Results from the UNITED study: a multicenter study validating the prognostic effect of the tumor-stroma ratio in colon cancer

BACKGROUND

The TNM (tumor-node-metastasis) Evaluation Committee of Union for International Cancer Control (UICC) and College of American Pathologists (CAP) recommended to prospectively validate the cost-effective and robust tumor-stroma ratio (TSR) as an independent prognostic parameter, since high intratumor stromal percentages have previously predicted poor patient-related outcomes.

PATIENTS AND METHODS

The 'Uniform Noting for International application of Tumor-stroma ratio as Easy Diagnostic tool' (UNITED) study enrolled patients in 27 participating centers in 12 countries worldwide. The TSR, categorized as stroma-high (>50%) or stroma-low (≤50%), was scored through standardized microscopic assessment by certified pathologists, and effect on disease-free survival (DFS) was evaluated with 3-year median follow-up. Secondary endpoints were benefit assessment of adjuvant chemotherapy (ACT) and overall survival (OS).

RESULTS

A total of 1537 patients were included, with 1388 eligible stage II/III patients curatively operated between 2015 and 2021. DFS was significantly shorter in stroma-high (n = 428) than in stroma-low patients (n = 960) (3-year rates 70% versus 83%; P < 0.001). In multivariate analysis, TSR remained an independent prognosticator for DFS (P < 0.001, hazard ratio 1.49, 95% confidence interval 1.17-1.90). As secondary outcome, DFS was also worse in stage II and III stroma-high patients despite adjuvant treatment (3-year rates stage II 73% versus 92% and stage III 66% versus 80%; P = 0.008 and P = 0.011, respectively). In stage II patients not receiving ACT (n = 322), the TSR outperformed the American Society of Clinical Oncology (ASCO) criteria in identifying patients at risk of events (event rate 21% versus 9%), with a higher discriminatory 3-year DFS rate (stroma-high 80% versus ASCO high risk 91%). A trend toward worse 5-year OS in stroma-high was noticeable (74% versus 83% stroma-low; P = 0.102).

CONCLUSION

The multicenter UNITED study unequivocally validates the TSR as an independent prognosticator, confirming worse outcomes in stroma-high patients. The TSR improved current selection criteria for patients at risk of events, and stroma-high patients potentially experienced chemotherapy resistance. TSR implementation in pathology diagnostics and international guidelines is highly recommended as aid in personalized treatment.

The Assessment of Burden of ColoRectal Cancer (ABCRC)-tool; a validity and reliability study

INTRODUCTION

Follow-up care after treatment for colorectal cancer (CRC) is increasingly focused on health-related quality of life (HRQoL) and functional outcomes. The Assessment of Burden of ColoRectal Cancer (ABCRC)-tool is developed to measure these outcomes and support patient-oriented care. The tool comprises items assessing burden of disease and lifestyle parameters. It consists of a generic module combined with one of the three CRC specific modules. The objective of this study is to assess the construct validity and reliability of the items of the ABCRC-tool.

METHODS

Patients who were receiving follow-up care after surgical CRC treatment were invited to complete the ABCRC-tool together with other validated patient-reported outcome measures (PROMs). Construct validity was assessed by testing expected correlations between items of the ABCRC-tool and domains of other PROMs and by examining predefined hypotheses regarding differences in subgroups of patients. Patients completed the ABCRC-tool twice, with 8 days apart, to evaluate its reliability.

RESULTS

In total, 177 patients participated (64% male) with a mean age of 67 years (range 33-88). The colon, rectum and stoma module were completed by subsequently 89, 53 and 35 patients. Most items correlated as expected with anticipated domains of the EORTC QLQ-C30 or EORTC QLQ-CR29 (all p-values <0.05). Furthermore, the ABCRC-tool could discriminate between subgroups of patients. The intraclass correlation coefficient (ICC) was good (>0.70) for most items, indicating good reliability.

CONCLUSION

The ABCRC-tool is a valid and reliable instrument that is ready for use in a clinical setting to support personalized follow-up care after CRC treatment.

Harnessing the Potential of Real-World Evidence in the Treatment of Colorectal Cancer: Where Do We Stand?

OPINION STATEMENT

Treatment guidelines for colorectal cancer (CRC) are primarily based on the results of randomized clinical trials (RCTs), the gold standard methodology to evaluate safety and efficacy of oncological treatments. However, generalizability of trial results is often limited due to stringent eligibility criteria, underrepresentation of specific populations, and more heterogeneity in clinical practice. This may result in an efficacy-effectiveness gap and uncertainty regarding meaningful benefit versus treatment harm. Meanwhile, conduct of traditional RCTs has become increasingly challenging due to identification of a growing number of (small) molecular subtypes. These challenges-combined with the digitalization of health records-have led to growing interest in use of real-world data (RWD) to complement evidence from RCTs. RWD is used to evaluate epidemiological trends, quality of care, treatment effectiveness, long-term (rare) safety, and quality of life (QoL) measures. In addition, RWD is increasingly considered in decision-making by clinicians, regulators, and payers. In this narrative review, we elaborate on these applications in CRC, and provide illustrative examples. As long as the quality of RWD is safeguarded, ongoing developments, such as common data models, federated learning, and predictive modelling, will further unfold its potential. First, whenever possible, we recommend conducting pragmatic trials, such as registry-based RCTs, to optimize generalizability and answer clinical questions that are not addressed in registrational trials. Second, we argue that marketing approval should be conditional for patients who would have been ineligible for the registrational trial, awaiting planned (non) randomized evaluation of outcomes in the real world. Third, high-quality effectiveness results should be incorporated in treatment guidelines to aid in patient counseling. We believe that a coordinated effort from all stakeholders is essential to improve the quality of RWD, create a learning healthcare system with optimal use of trials and real-world evidence (RWE), and ultimately ensure personalized care for every CRC patient.

Cumulative Incidence, Risk Factors, and Overall Survival of Disease Recurrence after Curative Resection of Stage II-III Colorectal Cancer: A Population-based Study

Real-world data are necessitated to counsel patients about the risk for recurrent disease after curative treatment of colorectal cancer. This study provided a population-based overview of the epidemiology of recurrent disease in patients with surgically resected stage II/III colorectal cancer.Patients diagnosed with stage II/III primary colorectal cancer between July and December 2015 were selected from the Netherlands Cancer Registry (N = 3,762). Cumulative incidence of recurrent disease was estimated, and multivariable competing risk regression was used to identify risk factors for recurrent disease in patients with primary colon and rectal cancer. Moreover, overall survival (OS) after diagnosis of recurrent colorectal cancer was estimated.Median clinical follow-up was 58 months (Q1-Q3: 22-62). Five-year cumulative incidence of recurrent disease was 21.6% [95% confidence interval (CI): 20.0-23.2] and 30.0% (95% CI: 28.3-33.5) for patients with primary colon and rectal cancer, respectively. Stage III disease and incomplete resection margin in patients with primary colon cancer and extramural vascular invasion in patients with primary rectal cancer were strongly (HR ≥ 2) associated with recurrent disease. Median OS of patients with distant, locoregional, or the synchronous combination of distant and locoregional recurrent disease was 29, 27, and 13 months, respectively (P < 0.001). Patients with distant recurrences limited to liver or lung showed a median OS of 46 and 48 months, respectively. The incidence of recurrent disease was higher in patients with rectal cancer than in patients with colon cancer, predominantly due to higher rates of distant recurrences. OS after recurrent disease was impaired, but subgroups of patients diagnosed with recurrent disease limited to one site showed statistically significantly longer OS.

SIGNIFICANCE

Population-based data on recurrent colorectal cancer are rare, but crucial for counseling patients and their physicians. This large nationwide, population-based study provides an up-to-date overview of the epidemiology of recurrent disease in patients with stage II and III primary colon and rectal cancer treated with surgical resection.

Oncological outcomes of screen-detected and non-screen-detected T1 colorectal cancers

BACKGROUND AND STUDY AIMS

The incidence of T1 colorectal cancers (CRC) has increased with the implementation of CRC screening programs. It is unknown if outcomes and and risk models for T1 CRC patients, based on non-screen-detected cases, can be extrapolated to screen-detected T1 CRC. This study aims to compare stage distribution and oncological outcomes of T1 CRC patients within and outside the screening program.

PATIENTS AND METHODS

Data from T1 CRC patients diagnosed between 2014-2017 were collected from 12 hospitals in the Netherlands. The presence of lymph node metastasis (LNM) at diagnosis was compared between screen-detected and non-screen-detected patients using multivariable logistic regression. Cox proportional hazard regression was employed to analyze differences in time to recurrence (TTR), metastasis-free survival (MFS), cancer-specific survival (CSS), and overall survival (OS). Additionally, the performance of conventional risk factors for LNM was evaluated in both groups.

RESULTS

1803 patients were included, of which 1114 (62%) were screen-detected. Median follow-up was 51 months (IQR 30). The proportion of LNM did not significantly differ between screen- and non-screen-detected patients (12.6% vs 8.9%; OR 1.41; 95% CI 0.89-2.23), and a prediction model for LNM performed equally in both groups. Three and 5-year TTR, MFS, and CSS were similar for patients within and outside the screening program. However, OS was significantly higher in screen-detected T1 CRC patients (adjusted HR 0.51; 95% CI 0.38-0.68).

CONCLUSIONS

Screen-detected and non-screen-detected T1 CRCs have similar stage distributions and oncological outcomes and can therefore be treated equally. However, screen-detected T1 CRC patients exhibit a lower rate of non-CRC-related mortality, resulting in higher OS.

Impact of colorectal cancer screening on survival after metachronous metastasis

BACKGROUND

An increasing proportion of colorectal cancer (CRC) cases in Europe are detected by screening with faecal immunochemical testing (FIT). Previous studies showed that population screening with FIT leads to a decrease in CRC incidence and to detection at an earlier stage. However, approximately twenty percent of patients with CRC without metastases at initial diagnosis still develop metachronous metastases. We investigated the association between detection mode of the primary tumor and overall survival (OS) after metachronous metastasis in patients with CRC.

METHODS

Nationwide registry-based data was obtained of 794 patients who developed metachronous metastases after being diagnosed with stage I-III CRC between January and June 2015. With multivariable Cox PH regression modelling, we analyzed the (causal) association between detection mode of the primary tumor (FIT screen-detected versus non-screen-detected) and OS after metachronous metastasis while adjusting for potential confounders.

RESULTS

Median OS and five-year OS after metachronous metastasis were significantly higher for patients with screen-detected (n = 152) vs. non-screen-detected primary tumors (n = 642): 38.3 vs. 19.2 months, and 35.4% vs. 18.8%, respectively, p < 0.0001). After adjustment for potential confounders, the association between detection mode and OS after metachronous metastasis remained significant (HR 0.70 [95% CI 0.56-0.89]).

CONCLUSIONS

Screen-detection of the primary tumor was independently associated with longer OS after metachronous metastasis. This may support the clinical utility of the population screening program and it shows the prognostic value of detection mode of the primary tumor once metachronous metastasis is diagnosed.

A scenario-drafting study to explore potential future implementation pathways of circulating tumor DNA testing in oncology

Circulating tumor DNA (ctDNA) detection has multiple promising applications in oncology, but the road toward implementation in clinical practice is unclear. We aimed to support the implementation process by exploring potential future pathways of ctDNA testing. To do so, we studied four ctDNA-testing applications in two cancer types and elicited opinions from 30 ctDNA experts in the Netherlands. Our results showed that the current available evidence differed per application and cancer type. Tumor profiling and monitoring treatment response were found most likely to be implemented in non-small cell lung cancer (NSCLC) within 5 years. For colorectal cancer, applications of ctDNA testing were found to be at an early stage in the implementation process. Demonstrating clinical utility was found a key aspect for successful implementation, but there was no consensus regarding the evidence requirements. The next step toward implementation is to define how clinical utility of biomarkers should be evaluated. Finally, these data indicate that specific challenges for each clinical application and tumor type should be appropriately addressed in a deliberative process involving all stakeholders to ensure implementation of ctDNA testing and timely access for patients.

Towards patient-led follow-up after curative surgical resection of stage I, II and III colorectal cancer (DISTANCE-trial): a study protocol for a stepped-wedge cluster-randomised trial

BACKGROUND

Colorectal cancer (CRC) is among the most frequently diagnosed cancers. Approximately 20-30% of stage I-III CRC patients develop a recurrent tumour or metastases after curative surgical resection. Post-operative follow-up is indicated for the first five years after curative surgical resection. As intensified follow-up after curative surgical resection has shown no effect on survival, patient organisations and policy makers have advocated for a more patient-centred approach to follow-up. The objective of this study is to successfully implement patient-led, home-based follow-up (PHFU) in six hospitals in The Netherlands, with as ultimate aim to come to a recommendation for a patient-centred follow-up schedule for stage I-III CRC patients treated with surgical resection with curative intent.

METHODS

This study is designed as a stepped-wedge cluster-randomised trial (SW-CRT) in six participating centres. During the trial, three centres will implement PHFU after six months; the other three centres will implement PHFU after 12 months of inclusion in the control group. Eligible patients are those with pT2-4N0M0 or pT1-4N1-2M0 CRC, who are 18 years or older and have been free of disease for 12 months after curative surgical resection. The studied intervention is PHFU, starting 12 months after curative resection. The in-hospital, standard-of-care follow-up currently implemented in the participating centres functions as the comparator. The proportion of patients who had contact with the hospital regarding CRC follow-up between 12-24 months after curative surgical resection is the primary endpoint of this study. Quality of life, fear of cancer recurrence, patient satisfaction, cost-effectiveness and survival are the secondary endpoints.

DISCUSSION

The results of this study will provide evidence on whether nationwide implementation of PHFU for CRC in The Netherlands will be successful in reducing contact between patient and health care provider. Comparison of PROMs between in-hospital follow-up and PHFU will be provided. Moreover, the cost-effectiveness of PHFU will be assessed.

TRIAL REGISTRATION

Dutch Trail Register (NTR): NL9266 (Registered on January 1st, 2021).

Prognostic value of Lynch syndrome, BRAFV600E , and RAS mutational status in dMMR/MSI-H metastatic colorectal cancer in a pooled analysis of Dutch and French cohorts

BACKGROUND

Current knowledge on prognostic biomarkers (especially BRAFV600E /RAS mutations) in metastatic colorectal cancer (mCRC) is mainly based on mCRC patients with proficient mismatch repair (pMMR) tumors. It is uncertain whether these biomarkers have the same prognostic value in mCRC patients with deficient mismatch repair (dMMR) tumors.

METHODS

This observational cohort study combined a population-based Dutch cohort (2014-2019) and a large French multicenter cohort (2007-2017). All mCRC patients with a histologically proven dMMR tumor were included.

RESULTS

In our real-world data cohort of 707 dMMR mCRC patients, 438 patients were treated with first-line palliative systemic chemotherapy. Mean age of first-line treated patients was 61.9 years, 49% were male, and 40% had Lynch syndrome. BRAFV600E mutation was present in 47% of tumors and 30% harbored a RAS mutation. Multivariable regression analysis on OS showed significant hazard rates (HR) for known prognostic factors as age and performance status, however showed no significance for Lynch syndrome (HR: 1.07, 95% CI: 0.66-1.72), BRAFV600E mutational status (HR: 1.02, 95% CI: 0.67-1.54), and RAS mutational status (HR: 1.01, 95% CI: 0.64-1.59), with similar results for PFS.

CONCLUSION

BRAFV600E and RAS mutational status are not associated with prognosis in dMMR mCRC patients, in contrast to pMMR mCRC patients. Lynch syndrome is also not an independent prognostic factor for survival. These findings underline that prognostic factors of patients with dMMR mCRC are different of those with pMMR, which could be taken into consideration when prognosis is used for clinical decision-making in dMMR mCRC patients and underline the complex heterogeneity of mCRC.

Comparison of NTRK fusion detection methods in microsatellite-instability-high metastatic colorectal cancer

Tropomyosin receptor kinase (TRK) inhibitors have been approved for metastatic solid tumors harboring NTRK fusions, but the detection of NTRK fusions is challenging. International guidelines recommend pan-TRK immunohistochemistry (IHC) screening followed by next generation sequencing (NGS) in tumor types with low prevalence of NTRK fusions, including metastatic colorectal cancer (mCRC). RNA-based NGS is preferred, but is expensive, time-consuming, and extracting good-quality RNA from FFPE tissue is challenging. Alternatives in daily clinical practice are warranted. We assessed the diagnostic performance of RNA-NGS, FFPE-targeted locus capture (FFPE-TLC), fluorescence in situ hybridization (FISH), and the 5'/3' imbalance quantitative RT-PCR (qRT-PCR) after IHC screening in 268 patients with microsatellite-instability-high mCRC, the subgroup in which NTRK fusions are most prevalent (1-5%). A consensus result was determined after review of all assay results. In 16 IHC positive tumors, 10 NTRK fusions were detected. In 33 IHC negative samples, no additional transcribed NTRK fusions were found, underscoring the high sensitivity of IHC. Sensitivity of RNA-NGS, FFPE-TLC, FISH, and qRT-PCR was 90%, 90%, 78%, and 100%, respectively. Specificity was 100% for all assays. Robustness, defined as the percentage of samples that provided an interpretable result in the first run, was 100% for FFPE-TLC, yet more limited for RNA-NGS (85%), FISH (70%), and qRT-PCR (70%). Overall, we do not recommend FISH for the detection of NTRK fusions in mCRC due to its low sensitivity and limited robustness. We conclude that RNA-NGS, FFPE-TLC, and qRT-PCR are appropriate assays for NTRK fusion detection, after enrichment with pan-TRK IHC, in routine clinical practice.

Abstract 3358: PLCRC-PROVENC3: assessing the prognostic value of post-surgery liquid biopsy cell-free circulating tumor DNA in stage III colon cancer patients

Introduction: Surgery followed by adjuvant chemotherapy (ACT) is standard of care in stage III colon cancer. However, 50% of the patients would be cured by surgery alone and are being overtreated, while 30-35% will experience a recurrence despite adjuvant treatment, resulting in only 15-20% of the patients benefitting from ACT. Therefore, there is a need for prognostic biomarkers to better stratify this group of patients for ACT decisions. Recent observational and interventional studies in non-metastatic colon cancer have shown that detection of cell-free circulating tumor DNA (ctDNA) in blood after surgery is highly prognostic for development of recurrence. Hence, ctDNA analysis is a promising approach to guide treatment decisions in stage III colon cancer, but studies with large well-defined patient cohorts are needed to prove clinical utility.

Aim: Determine the prognostic value of ctDNA in stage III colon cancer patients treated with ACT to reduce futile treatment.

Methods: 241 stage III colon cancer patients treated with ACT were included in the prospective observational study “PROVENC3” (PROgnostic Value of Early Notification by Ctdna in Colon Cancer stage 3), a substudy of the Prospective Dutch Colorectal Cancer cohort (PLCRC). The PLCRC infrastructure accrued patients with colorectal cancer in 23 participating hospitals in the Netherlands. After informed consent, blood was collected pre-surgery, post-surgery, post-ACT and every six months up to 3 years. Tumor-informed detection of ctDNA was performed through integrated whole genome sequencing (WGS) analyses of formalin-fixed paraffin-embedded tumor tissue DNA (80x), germline DNA (40x), and plasma cell-free DNA (30x).

Results: Patient accrual was completed in 2021, with a median follow-up of 35.6 months. In total, 1090 blood samples have been collected to date. Analytical studies demonstrated a limit of detection of the test of 0.005% ctDNA utilizing contrived reference models derived from six independent cell lines, with a specificity of 99.6% across 119 noncancerous donor plasma specimens. From the PROVENC3 study, ctDNA analyses are ongoing for pre-surgery (n=68) and post-surgery (n=241 patients) blood samples. Preliminary results demonstrated a ctDNA detection rate of 93.4% pre-surgery and 17.1% post-surgery, which was associated with disease recurrence. Final analysis will enable determination of: 1) the proportion of ctDNA-positive/negative patients after surgery and the corresponding recurrence rates; 2) the prognostic value of post-surgery ctDNA; and 3) the lead time between post-surgery ctDNA detection and recurrence.

Future Perspective: Ultimately, the results of this study will be used to model and design a ctDNA-guided interventional trial in stage III colon cancer patients, to reduce futile ACT and its associated side-effects.

Citation Format: Carmen Rubio-Alarcon, Steven L. Ketelaars, Ingrid A. Franken, Sietske C. van Nassau, Dave E. van der Kruijssen, Suzanna J. Schraa, Theodora C. Linders, Pien Delis-van Diemen, Maartje Alkemade, Anne Bolijn, Marianne Tijssen, Margriet Lemmens, Miranda van Dongen, Mirthe Lanfermeijer, Annegien Broeks, Lana Meiqari, Linda J. Bosch, Victor E. Velculescu, Amy Greer, Samuel V. Angiuoli, Andrew Georgiadis, David Riley, James R. White, Christopher Greco, Liam Cox, Daan van den Broek, Cornelis J. Punt, Veerle M. Coupé, Miriam Koopman, Jeanine Roodhart, Gerrit A. Meijer, Mark Sausen, Geraldine R. Vink, Remond J. Fijneman. PLCRC-PROVENC3: assessing the prognostic value of post-surgery liquid biopsy cell-free circulating tumor DNA in stage III colon cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3358.

Abstract 3366: A machine learning approach to determine the cellular origin of variants in liquid biopsies

Introduction: Targeted next-generation sequencing (NGS) of cell-free DNA in plasma, referred to as liquid biopsy, has become a valuable diagnostic tool in clinical oncology. However, detection of variants related to clonal hematopoiesis (CH) is a major confounder that significantly impairs the clinical utility of liquid biopsies. Here we developed a machine-learning model to determine tumor versus CH origin of variants identified in plasma-only NGS.

Methods: We assembled a training cohort of 352 variants identified by targeted deep plasma sequencing from 199 patients with stage I-IV breast, colorectal, esophageal, lung, and ovarian cancer, coupled with matched white blood cell (WBC) and tumor tissue NGS to allow determination of the reference origin for each plasma variant. We employed Extreme Gradient Boosting (XGBoost) to integrate fragment, variant, gene, and patient level features to predict tumor versus CH plasma variant origin, evaluating the performance of this approach within the training cohort using 10-fold cross-validation. We applied the fixed model to two independent validation cohorts: a small cell lung cancer (SCLC) cohort comprising of 74 variants from targeted plasma NGS from 26 patients and a multi-cancer cohort of 409 variants detected using the MSK-Impact panel from 74 patients with breast, colorectal, and prostate cancer.

Results: Variant allele frequencies (VAF) did not differentiate tumor from CH variants, as the VAFs between tumor (median VAF 0.53%) and CH (median VAF 0.409%) variants in the training cohort were largely overlapping (area under the ROC curve-AUC 0.54, 95% confidence interval-CI 0.48-0.61). Similarly, individual fragmentomic features (mutant fragment length, cut points, and endpoint motifs) had limited ability to distinguish tumor from CH variants (AUC range 0.51-0.76). Using serial plasma samples, we identified stable statistical measures of differences in fragment feature distributions between mutant and wild type fragments; these were subsequently incorporated into an XGBoost machine-learning model along with variant, gene and patient features to predict tumor versus CH variant origin. Our model predicted variant origin with an AUC of 0.95 (95% CI 0.87-1) from 10-fold cross validation in the training cohort. The performance of the model was tested in independent SCLC and multi-cancer validation cohorts; the fixed model predicted plasma variant origin with an AUC of 0.87 (95% CI 0.73-1) and 0.89 (95% CI 0.86-0.92) respectively.

Conclusion: We developed a machine-learning model that integrates patient, gene, variant and fragment features to predict tumor versus CH origin of plasma variants across solid tumors and NGS sequencing platforms. The ability to identify bona fide tumor variants in plasma-only sequencing fills a critical need in the clinical implementation of liquid biopsy-guided cancer therapy by reducing misinterpretation due to CH contamination.

Citation Format: Jenna V. Canzoniero, Archana Balan, Jillian Phallen, Blair V. Landon, Lavanya Sivapalan, Benjamin Green, Zineb Belcaid, Susan C. Scott, Gavin Pereira, Vincent K. Lam, Ali H. Zaidi, Ronan J. Kelly, Christine L. Hann, Wade T. Iams, Christine M. Lovly, Patrick M. Forde, Gerrit A. Meijer, Geraldine R. Vink, Remond J. Fijneman, The MEDOCC Group, Victor E. Velculescu, Robert B. Scharpf, Valsamo Anagnostou. A machine learning approach to determine the cellular origin of variants in liquid biopsies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3366.

Time-varying prognostic value of primary tumor sidedness in metastatic colorectal cancer: A population-based study and meta-analysis

We studied the prognostic value of primary tumor sidedness in metastatic colorectal cancer over time and across treatment lines. Population data on synchronous metastatic colorectal cancer patients were extracted from the Netherlands Cancer Registry and SEER database. Pubmed, EMBASE and Cochrane library were searched for prospective studies on metastatic colorectal cancer to conduct a meta-analysis. Inclusion criteria consisted of metastatic disease, systemic treatment with palliative intent and specification of primary tumor location. Data were pooled using a random-effects model. For the population-based data, multivariable Cox models were constructed. The Grambsch-Therneau test was conducted to evaluate the potential time-varying nature of sidedness. Meta-regression incorporating treatment-line as variable was conducted to test the pre-specified hypothesis that the prognostic value of sidedness varies over time. Analysis of 12 885 and 16 160 synchronous metastatic colorectal cancer patients registered in the Netherlands Cancer Registry and SEER database, respectively, indicated a time-varying prognostic value of sidedness (P < .01). Thirty-one studies were selected for the meta-analysis (9558 patients for overall survival analysis). Pooled univariable hazard ratio_{left-sided/right-sided} for overall survival was 0.71 (95% CI: 0.65-0.76) in 1st-line, 0.76 (0.54-1.06) in 2nd-line and 1.01 (0.86-1.19) in 3rd-line studies. Hazard ratios were significantly influenced by treatment line (P = .035). The prognostic value of sidedness of the primary tumor in metastatic colorectal cancer patients treated with palliative systemic therapy decreases over time since diagnosis, suggesting that sidedness may not be a useful stratification factor in late-line trials. This decrease in prognostic value should be taken into account when providing prognostic information to patients.

Health-related quality-of-life trajectories during/after surgery and adjuvant chemotherapy in patients with colon cancer

PURPOSE

This study aims to evaluate quality of life trajectory during the first year after surgical treatment in patients with resectable primary colon cancer.

METHODS

Patients with resectable primary colon cancer diagnosed between 2013 and 2019 who received surgical treatment and adjuvant chemotherapy if indicated were selected from the Prospective Dutch ColoRectal Cancer cohort study (PLCRC). Health-related quality of life (HR-QoL) was assessed using EORTC-QLQ-C30 questionnaire before surgery, and three and twelve months after surgery. HR-QoL scores varied between 0 and 100 and outcomes were compared according to age (< 70 years, ≥ 70 years), comorbidity (yes, no) and treatment type (adjuvant chemotherapy, surgical treatment only). The extent of resilience, defined as a recovery of HR-QoL to baseline level after a clinically relevant decline in HR-QoL at months, was calculated twelve months post-surgery.

RESULTS

For all 458 patients, the mean age was 66.4 years (SD 9.5), 40% were aged 70 years and older and 68% were men. Baseline level of HR-QoL summary score was relatively high with a mean of 87.9 (SD 11.5), and did not significantly differ between older and younger patients. The strongest decline of HR-QoL compared to baseline was observed at three months with a gradual recovery over time. Fourteen percent of all patients were non-resilient or showed a late decline at twelve months post-surgery. Compared to younger patients, older patients who received adjuvant chemotherapy were less resilient (respectively, 53 and 32%, p = 0.07) and at risk of a late decline in HR-QoL 1 year post-surgery (respectively, 3% versus 16%, p = 0.02). Comorbidity status had no significant impact on the HR-QoL trajectory.

CONCLUSION

Colon cancer treatment was associated with a decline in HR-QoL three months post-surgery, but most patients return to baseline level within twelve months. Still, particularly older patients who received adjuvant chemotherapy were less resilient and at risk of a late decline in HR-QoL. These data could help in patients counselling regarding colon cancer treatment.

Predicting early extrahepatic recurrence after local treatment of colorectal liver metastases

BACKGROUND

Patients who develop early extrahepatic recurrence (EHR) may not benefit from local treatment of colorectal liver metastases (CRLMs). This study aimed to develop a prediction model for early EHR after local treatment of CRLMs using a national data set.

METHODS

A Cox regression prediction model for EHR was developed and validated internally using data on patients who had local treatment for CRLMs with curative intent. Performance assessment included calibration, discrimination, net benefit, and generalizability by internal-external cross-validation. The prognostic relevance of early EHR (within 6 months) was evaluated by landmark analysis.

RESULTS

During a median follow-up of 35 months, 557 of the 1077 patients had EHR and 249 died. Median overall survival was 19.5 (95 per cent c.i. 15.6 to 23.0) months in patients with early EHR after CRLM treatment, compared with not reached (45.3 months to not reached) in patients without an early EHR. The EHR prediction model included side and stage of the primary tumour, RAS/BRAFV600E mutational status, and number and size of CRLMs. The range of 6-month EHR predictions was 5.9-56.0 (i.q.r. 12.9-22.0) per cent. The model demonstrated good calibration and discrimination. The C-index through 6 and 12 months was 0.663 (95 per cent c.i. 0.624 to 0.702) and 0.661 (0.632 to 0.689) respectively. The observed 6-month EHR risk was 6.5 per cent for patients in the lowest quartile of predicted risk compared with 32.0 per cent in the highest quartile.

CONCLUSION

Early EHR after local treatment of CRLMs can be predicted.

Clinical outcomes in patients with microsatellite instability-high (MSI-H) metastatic colorectal cancer (mCRC) in the pre-immunotherapy era

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Background: Data on clinical treatment outcomes of systemic non-immunotherapy in patients with MSI-H mCRC are limited due to low incidence. Real world data can support the interpretation of immunotherapy studies. Our aim is to provide insight on clinical outcomes of patients with MSI-H mCRC treated with systemic non-immunotherapy. Methods: We describe an observational cohort study with real-world data from the Netherlands Cancer Registry during 2015-2018 (N=383) and trial-based data from three prospective phase III first-line clinical trials: CAIRO, CAIRO2 and CAIRO3 (N=54). We investigated progression free survival (PFS) and overall survival (OS), which were defined as time from the start of first-line (PFS1/OS1), second-line (PFS2/OS2) and third-line (PFS3/OS3) of systemic non-immunotherapy until disease progression or death, respectively. Furthermore, we investigated objective response rate (ORR), which was defined as the proportion of patients with a complete or partial response as best response after first-line (ORR1), second-line (ORR2) and third-line (ORR3). Results: A total of 437 patients with MSI-H mCRC were analyzed. The proportion of patients receiving at least one line of systemic non-immunotherapy was 63%, 21% received two lines, and 5% received three lines. Patients receiving one line of therapy (N=270) had a median age of 69, 50% were female, 49% had a WHO performance score of 0, 70% had a right-sided tumor, 72% had synchronous mCRC, and 64% of those with synchronous mCRC received primary tumor resection. When known, 52% of patients harbored a BRAF mutation and 21% a RAS mutation. The results of OS, PFS, and ORR are summarized. Conclusions: To our knowledge these results provide insight on clinical outcomes in the largest observational cohort of patients with MSI-H mCRC treated with systemic non-immunotherapy to date. We showed a median PFS1 of 5.9 months and an OS1 of 14.1 months, which are in distinct contrast with patients in MSI-H mCRC trials receiving mono-immunotherapy in which a median PFS1 of 16.5 months was reached and a median OS1 was not reached after median follow-up of 44.5 months. Only 21% of patients in our observational cohort reached second-line of systemic non-immunotherapy and 5% third-line. Our results underline the importance and early access to immunotherapy in the MSI-H mCRC population. [Table: see text]

The impact of surgery and adjuvant chemotherapy on health-related quality of life in patients with colon cancer: Changes at group level versus individual level

OBJECTIVE

This study aims to evaluate changes in health-related quality of life (HR-QoL) 1 year after surgical treatment in patients with primary resectable colon cancer and to assess whether changes at group level differ from changes at individual level. In addition, we assess which characteristics are associated with a decline of HR-QoL.

METHODS

Patients with primary resectable colon cancer who received surgical treatment and adjuvant chemotherapy if indicated were selected from the Prospective Dutch ColoRectal Cancer cohort (PLCRC). HR-QoL was assessed using EORTC-QLQ-C30 questionnaire before surgery and 12 months post-surgery. Outcomes were assessed at group and individual levels. Logistic regression analysis was conducted to assess which socio-demographic and clinical characteristics were associated with a clinically relevant decline of HR-QoL at 12 months.

RESULTS

Of all 324 patients, the baseline level of HR-QoL summary score was relatively high with a mean of 88.1 (SD 11.4). On group level, the change of HR-QoL at 12 months varied between -2% for cognitive functioning and +9% for emotional functioning. On individual level, 15% of all patients experienced a clinically relevant decline in HR-QoL summary score at 12 months. Older age, comorbidity burden or the reception of adjuvant chemotherapy was independently associated with a decline of HR-QoL in one of the functional subscales of EORTC-QLQ-C30 at 12 months.

CONCLUSION

Only trivial changes of HR-QoL were observed after colon cancer treatment on group level, whereas on individual level, at least 1 out of 10 patients experienced a decline of HR-QoL 12 months post-surgery. It is important to consider individual differences while making a treatment decision.

Translation of IDEA trial results into clinical practice: analysis of the implementation of a new guideline for colon cancer

The IDEA trial showed no clinical relevant differences in efficacy between 3 and 6 months of oxaliplatin‐based adjuvant chemotherapy (ACT) in colon cancer (CC), while toxicity was substantially lower in the 3 months regimen. Therefore, in 2017 the Dutch colorectal cancer guideline was revised and currently recommends 3 months of oxaliplatin‐based ACT. Furthermore, the definition of high‐risk stage II CC was restricted to pT4 tumors. We analyzed changes in ACT between 2015 and 2019. From the Netherlands Cancer Registry all 16 721 patients ≥18 years with resected high‐risk stage II and stage III CC during 2015 to 2019 were selected. Differences in patient and treatment characteristics were analyzed per calendar year according to stage and age. Mean duration of oxaliplatin‐based ACT decreased from 18.6 (±8.0) to 9.5 (±3.8) weeks between 2015 and 2019. In patients receiving ACT (n = 8170), the proportion treated with oxaliplatin increased from 74% to 83%. The proportion of patients receiving ACT was stable, 61% to 69% in stage III and 26% to 29% in pT4 stage II. ACT in previous high‐risk pT3N0 disease decreased from 15% to 3%. Use of oxaliplatin increased from 27% to 49% in patients aged ≥75 years. The revised guideline was rapidly implemented and led to an increase in oxaliplatin‐based ACT in the elderly and increased guideline‐adherence in high‐risk stage II CC.

Evaluation of an individual feedback report on patient-reported outcomes in the Prospective Dutch ColoRectal Cancer cohort

PURPOSE

Returning patient-reported outcomes to patients might aid patients in detecting symptoms and might facilitate early intervention. This descriptive study evaluates the use of an individual feedback report on patient-reported outcomes for colorectal cancer patients and aims to assess differences in patient, tumor, and treatment characteristics and cohort retention between patients who opt and do not opt for the feedback report.

METHODS

Patients with colorectal cancer participating in the nationwide Prospective Dutch ColoRectal Cancer Cohort, who filled in questionnaires digitally between June 2018 and January 2019, were included. Participants were given the option to receive a feedback report at baseline, 3, 6, and 12 months. The usefulness, content, and layout of the feedback report were evaluated. Differences in patient, tumor, and treatment characteristics, patient-reported outcomes, and cohort retention at subsequent questionnaires between participants who did and did not opt for feedback were assessed.

RESULTS

A total of 484 participants were included of whom 293 (61%) opted for feedback. The feedback report was considered useful by 92%. No differences in patient, tumor, and treatment characteristics, and patient-reported outcomes were found between participants who did and did not opt for feedback. The response rate was higher among patients who opted for feedback compared to patients who did not opt for feedback at T3 (84 vs 74%), but not at T6 and T12.

CONCLUSION

The feedback report was used by 6 out of 10 patients. The feedback report was considered valuable and associated with a higher subsequent response rate.

External Validation of Two Established Clinical Risk Scores Predicting Outcome after Local Treatment of Colorectal Liver Metastases in a Nationwide Cohort

Optimized surgical techniques and systemic therapy have increased the number of patients with colorectal liver metastases (CRLM) eligible for local treatment. To increase postoperative survival, we need to stratify patients to customize therapy. Most clinical risk scores (CRSs) which predict prognosis after CRLM resection were based on the outcome of studies in specialized centers, and this may hamper the generalizability of these CRSs in unselected populations and underrepresented subgroups. We aimed to externally validate two CRSs in a population-based cohort of patients with CRLM. A total of 1105 patients with local treatment of CRLM, diagnosed in 2015/2016, were included from a nationwide population-based database. Survival outcomes were analyzed. The Fong and more recently developed GAME CRS were externally validated, including in pre-specified subgroups (≤70/>70 years and with/without perioperative systemic therapy). The three-year DFS was 22.8%, and the median OS in the GAME risk groups (high/moderate/low) was 32.4, 46.7, and 68.1 months, respectively (p < 0.005). The median OS for patients with versus without perioperative therapy was 47.6 (95%CI [39.8, 56.2]) and 54.9 months (95%CI [48.8, 63.7]), respectively (p = 0.152), and for below/above 70 years, it was 54.9 (95%CI [49.3−64.1]) and 44.2 months (95%CI [37.1−54.3]), respectively (p < 0.005). The discriminative ability for OS of Fong CRS was 0.577 (95%CI [0.554, 0.601]), and for GAME, it was 0.596 (95%CI [0.572, 0.621]), and was comparable in the subgroups. In conclusion, both CRSs showed predictive ability in a population-based cohort and in predefined subgroups. However, the limited discriminative ability of these CRSs results in insufficient preoperative risk stratification for clinical decision-making.

External validation of the MSKCC nomogram to estimate five-year overall survival after surgery for stage I-III colon cancer in a Dutch population

INTRODUCTION

The Memorial Sloan Kettering Cancer Centre (MSKCC) nomogram has been developed to estimate five-year overall survival (OS) after curative-intent surgery of colon cancer based on age, sex, T stage, differentiation grade, number of positive and examined regional lymph nodes. This is the first evaluation of the performance of the MSKCC model in a European population regarding prediction of OS.

MATERIAL AND METHODS

Population-based data from patients with stage I-III colon cancer diagnosed between 2010 and 2016 were obtained from the Netherlands Cancer Registry (NCR) for external validation of the MSKCC prediction model. Five-year survival probabilities were estimated for all patients in our dataset by using the MSKCC prediction equation. Histogram density plots were created to depict the distribution of the estimated probability and prognostic index. The performance of the model was evaluated in terms of its overall performance, discrimination, and calibration.

RESULTS

A total of 39,805 patients were included. Five-year OS was 71.9% (95% CI 71.5; 72.3) (11,051 events) with a median follow up of 5.6 years (IQR 4.1; 7.7). The Brier score was 0.10 (95% CI 0.10; 0.10). The C-index was 0.75 (95% CI 0.75; 0.76). The calibration measures and plot indicated that the model slightly overestimated observed mortality (observed/expected ratio = 0.86 [95% CI 0.86; 0.87], calibration intercept = -0.14 [95% CI -0.16; -0.11], and slope 1.07 [95% CI 1.05; 1.09], ICI = 0.04, E50 = 0.04, and E90 = 0.05).

CONCLUSIONS

The external validation of the MSKCC prediction nomogram in a large Dutch cohort supports the use of this practical tool in the European patient population. These personalised estimated survival probabilities may support clinicians when informing patients about prognosis. Adding potential relevant prognostic factors to the model, such as primary tumour location, might further improve the model.

Cell-Free Circulating (Tumor) DNA before Surgery as a Prognostic Factor in Non-Metastatic Colorectal Cancer: A Systematic Review

Identification of non-metastatic colorectal cancer (CRC) patients with a high risk of recurrence after tumor resection is important to select patients who might benefit from adjuvant treatment. Cell-free DNA (cfDNA) and circulating tumor DNA (ctDNA) analyses after surgery are promising biomarkers to predict recurrence in these patients. However, these analyses face several challenges and do not allow guidance of neoadjuvant treatment, which might become a novel standard option in colon cancer treatment. The prognostic value of cfDNA/ctDNA before surgery is unclear. This systematic review aims to provide an overview of publications in which the prognostic value of presurgery cfDNA/ctDNA in non-metastatic CRC patients was studied and is performed according to PRISMA guidelines. A total of 29 out of 1233 articles were included and categorized into three groups that reflect the type of approach: measurement of cfDNA, ctDNA somatic alterations, and ctDNA methylation. Overall, a clear association between presurgery cfDNA/ctDNA and the outcome was not observed, but large studies that primarily focus on the prognostic value of presurgery cfDNA/ctDNA are lacking. Designing and performing studies that focus on the value of presurgery cfDNA/ctDNA is needed, in addition to standardization in the reporting of cfDNA/ctDNA results according to existing guidelines to improve comparability and interpretation among studies.

Limited impact of the COVID-19 pandemic on colorectal cancer care in the Netherlands in 2020

PURPOSE

The COVID-19 pandemic had a major impact on the health services worldwide. We aimed to investigate the impact of the pandemic on colorectal cancer (CRC) care in the Netherlands in 2020.

METHODS

CRC patients, diagnosed in 2018-2020 in the Netherlands, were selected from the Netherlands Cancer Registry (NCR). The year 2020 was divided in four periods reflecting COVID-19 developments in the Netherlands (pre-COVID, 1st peak, recovery period, 2nd peak) and compared with the same periods in 2018/2019. Patient characteristics and treatment were compared using the Chi-squared test. Median time between diagnosis and treatment, and between (neo)adjuvant therapy and surgery were analyzed by the Mann-Whitney U test.

RESULTS

In total, 38,021 CRC patients were diagnosed in 2018/2019 (n = 26,816) and 2020 (n = 11,205). Median time between diagnosis and initial treatment decreased on average 4 days and median time between neoadjuvant radiotherapy and surgery in clinical stage II or III rectal cancer patients increased on average 34 days during the three COVID-19 periods compared to the same periods of 2018/2019. The proportion of colon cancer patients that underwent elective surgery significantly decreased with 3.0% during the 1st peak. No differences were found in the proportion of patients who received (neo)adjuvant therapy, systemic therapy, or no anti-cancer treatment.

CONCLUSION

Only minor changes in the care for CRC patients occurred during the COVID-19 pandemic, mostly during the 1^st peak. In conclusion, the impact on CRC care in the Netherlands was found to be limited. However, long-term effects cannot be precluded.

Colorectal cancer incidence, mortality, tumour characteristics, and treatment before and after introduction of the faecal immunochemical testing-based screening programme in the Netherlands: a population-based study

BACKGROUND

In 2014, a population-based colorectal cancer (CRC) screening programme was stepwise implemented in the Netherlands comprising faecal immunochemical testing once every 2 years, with a cutoff value for positivity of 47 μg haemoglobin per g faeces. We aimed to assess CRC incidence, mortality, tumour characteristics, and treatment before and after introduction of this screening programme.

METHODS

We did a retrospective, observational, population-based study in the Netherlands and gathered CRC incidence data from the Netherlands Cancer Registry from Jan 1, 2010, to Dec 31, 2019, in people aged 55 years or older. Patients with a CRC diagnosis between Jan 1, 2014, and Dec 31, 2018, in the Netherlands Cancer Registry were linked with the nationwide registry of histopathology and cytopathology (PALGA) to identify mode of detection (ie, screening-detected vs clinically detected). We calculated age-standardised CRC incidence rates and used data from Statistics Netherlands to calculate CRC-related mortality in 2010-19. We compared localisation, stage distribution, and treatment of screening-detected CRCs with clinically detected CRCs diagnosed in 2014-18 in patients aged 55-75 years.

FINDINGS

Between Jan 1, 2010, and Dec 31, 2019, 125 215 CRCs were diagnosed in individuals aged 55 years or older and were included in the analyses for CRC incidence. Before the introduction of the screening programme, the age-standardised CRC incidence rate was 214·3 per 100 000 population in 2013 in people aged 55 years or older. After the introduction of the screening programme, this rate initially increased to 259·2 per 100 000 population in 2015, and subsequently decreased to 181·5 per 100 000 population in 2019. Age-standardised incidence rates for advanced CRCs (stage III and IV) were 117·0 per 100 000 population in 2013 and increased to 122·8 per 100 000 population in 2015; this rate then decreased to 94·7 per 100 000 population in 2018. Age-standardised CRC mortality decreased from 87·5 deaths per 100 000 population in 2010 to 64·8 per 100 000 population in 2019. Compared with clinically detected CRCs, screening-detected CRCs were more likely to be located in the left side of the colon (48·6% vs 35·2%) and to be detected at an early stage (I or II; 66·7% vs 46·2%). Screening-detected CRCs were more likely to be treated by local excision compared with clinically detected CRCs, and this finding persisted when stage I CRCs were analysed separately.

INTERPRETATION

After introduction of this national screening programme, a decrease in overall and advanced-stage CRC incidence was observed. In view of this observation, together with the observed shift to detection at earlier stages and more screening-detected CRCs being treated by local excision, we might cautiously conclude that, in the long-term, faecal immunochemical testing-based screening could ultimately lead to a decrease in CRC-related morbidity and mortality.

FUNDING

None.

Nationwide evaluation of mutation-tailored anti-EGFR therapy selection in patients with colorectal cancer in daily clinical practice

For a nationwide real-word data study on the application of predictive mutation testing of patients with colorectal cancer (CRC) for anti-epidermal growth factor receptor (EGFR) therapy stratification, pathology data were collected from the Dutch Pathology Registry from October 2017 until June 2019 (N=4060) and linked with the Netherlands Cancer Registry. Mutation testing rates increased from 24% at diagnosis of stage IV disease to 60% after 20-23 months of follow-up (p<0.001). Application of anti-EGFR therapy in KRAS/NRAS wild-type patients was mainly observed from the third treatment line onwards (65% vs 17% in first/second treatment line (p<0.001)). The national average KRAS/NRAS/BRAF mutation rate was 63.9%, being similar for next-generation sequencing (NGS)-based approaches and single gene tests (64.4% vs 61.2%, p=ns). NGS-based approaches detected more additional potential biomarkers, for example, ERBB2 amplifications (p<0.05). Therefore, single gene tests are suitable to stratify patients with mCRC for anti-EGFR therapy, but NGS is superior enabling upfront identification of therapy resistance or facilitate enrolment into clinical trials.

Sixty-Day Mortality of Patients With Metastatic Colorectal Cancer Randomized to Systemic Treatment vs Primary Tumor Resection Followed by Systemic Treatment: The CAIRO4 Phase 3 Randomized Clinical Trial

Importance

The role of primary tumor resection (PTR) in synchronous patients with metastatic colorectal cancer (mCRC) who had unresectable metastases and few or absent symptoms of their primary tumor is unclear. Studying subgroups with low postoperative mortality may identify patients who potentially benefit from PTR.

Objective

To determine the difference in 60-day mortality between patients randomized to systemic treatment only vs PTR followed by systemic treatment, and to explore risk factors associated with 60-day mortality.

Design, Setting, and Participants

CAIRO4 is a randomized phase 3 trial initiated in 2012 in which patients with mCRC were randomized to systemic treatment only or PTR followed by systemic treatment with palliative intent. This multicenter study was conducted by the Danish and Dutch Colorectal Cancer Group in general and academic hospitals in Denmark and the Netherlands. Patients included between August 2012 and December 2019 with histologically proven colorectal cancer, unresectable metastases, and a primary tumor with few or absent symptoms were eligible.

Interventions

Systemic treatment, consisting of fluoropyrimidine-based chemotherapy with bevacizumab vs PTR followed by fluoropyrimidine-based chemotherapy with bevacizumab.

Main Outcomes and Measures

The aim of the current analysis was to compare 60-day mortality rates in both treatment arms. A secondary aim was the identification of risk factors for 60-day mortality in the treatment arms. These aims were not predefined in the study protocol.

Results

A total of 196 patients were included in the intention-to-treat analysis (112 [57%] men; median [IQR] age, 65 [59-70] years). Sixty-day mortality was 3% (95% CI, 1%-9%) in the systemic treatment arm and 11% (95% CI, 6%-19%) in the PTR arm (P = .03). In a per-protocol analysis, 60-day mortality was 2% (95% CI, 1%-7%) vs 10% (95% CI, 5%-18%; P = .048). Patients with elevated serum levels of lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase, and/or neutrophils who were randomized to PTR had a significantly higher 60-day mortality than patients without these characteristics.

Conclusions and Relevance

Patients with mCRC who were randomized to PTR followed by systemic treatment had a higher 60-day mortality than patients randomized to systemic treatment. Especially patients randomized to the PTR arm with elevated serum levels of lactate dehydrogenase, neutrophils, aspartate aminotransferase, and/or alanine aminotransferase were at high risk of postoperative mortality. Final study results on overall survival have to be awaited.

Trial Registration

ClinicalTrials.gov Identifier: NCT01606098.

Frailty and health related quality of life three months after non-metastatic colorectal cancer diagnosis in older patients: A multi-centre prospective observational study

BACKGROUND

Health related quality of life (HRQL) is an important outcome measure in geriatric oncology. Surgery is the main treatment for colorectal cancer (CRC) but has been associated with a loss of HRQL in older patients. This study aimed to identify determinants for a decreased HRQL at three months after CRC diagnosis.

METHOD

This multi-centre observational cohort study (NCT04443816) included 273 patients aged ≥70 years diagnosed with non-metastatic CRC. A multi-domain frailty screening was performed in each patient. A decreased HRQL was defined as a mean difference ≥ 10 on the EORTC QLQ-C30 questionnaire between baseline and three months after CRC diagnosis. Determinants of a decreased HRQL were analysed using multivariable logistic regression.

RESULTS

A decrease in HRQL occurred in 63 patients (23.1%). Non-surgical patients had the highest risk of decreased HRQL three months after diagnosis (adjusted odds ratio (OR) 6.4 (95% confidence interval (CI) 2.0-19.8)). The Charlson Comorbidity Index (CCI) (aOR 2.3 (95% (CI) 1.2-4.2)), the American Association of Anesthesiologists class (aOR 2.6 (95%CI 1.4-4.9)), impaired daily functioning (aOR 2.7 (95%CI 1.3-5.6)) and dependent living (aOR 1.9 (95%CI 1.1-4.5)) were associated with a decreased HRQL, mainly caused by non-surgical patients. In surgical patients, a major postoperative complication was a strong determinant of decreased HRQL and was associated with preoperative comorbidity and cognitive impairment (aOR 4.0 (95%CI 1.9-8.8)).

CONCLUSION

Frailty characteristics are highly prevalent in older patients at time of CRC diagnosis but not strongly associated with a decreased HRQL after three months. Non-surgical patients and patients with major postoperative complications had the highest risk of decreased HRQL. Registered at clinicaltrials.gov trial number: NCT04443816.

Role of Up-Front Primary Tumor Resection and Tumor Sidedness in the Survival of Synchronous Metastatic Colon Cancer Patients

INTRODUCTION

Uncertainty exists about a possible survival benefit of primary tumor resection (PTR) in synchronous metastatic colon cancer (mCC). Since sidedness of the primary tumor is regarded as an important prognostic factor, our objective was to study the interaction between PTR and sidedness in synchronous mCC.

METHODS

In this retrospective study, we used data from 2 first-line phase 3 randomized controlled trials (RCTs). A mixed Cox regression model was used to study the multiplicative interaction between PTR and sidedness. We adjusted for age, treatment arm, WHO performance status, number of affected organs by metastases, serum lactate dehydrogenase, and year of enrollment.

RESULTS

We found that PTR is associated with better survival in both right-sided (hazard ratio [HR] 0.59 [95% confidence interval 0.42-0.8 2]) and left-sided mCC (HR 0.70 [95% confidence interval 0.52-0.93]). The interaction between PTR and sidedness was not significant (p = 0.45).

CONCLUSION

Our data suggest that the prognostic value of PTR is independent of sidedness. Validation of these results will be performed in ongoing RCTs.

Abstract CT251: MEDOCC-CrEATE trial in progress: effectiveness of adjuvant chemotherapy in stage II colon cancer patients with positive circulating tumor DNA

Background Accurate detection of patients with minimal residual disease (MRD) after resection of localized colon cancer remains an unmet clinical need as these patients might benefit from adjuvant chemotherapy (ACT). For stage II colon cancer, ACT is only indicated in patients with a pT4 tumor without a deficient mismatch repair system (dMMR), according to Dutch guidelines. However, recurrence rate (RR) in stage II colon cancer is still 15-20%. Circulating tumor DNA (ctDNA), consisting of small fragments of DNA containing tumor-specific mutations, has been shown to be a promising biomarker for MRD and a strong predictor for recurrent disease when detectable after resection. The MEDOCC-CrEATE trial investigates how many stage II colon cancer patients with detectable ctDNA after surgery will accept ACT and whether ACT reduces RR in these patients.

Methods The MEDOCC-CrEATE study follows the ‘trials within cohorts' (TwiCs) design. Patients with colorectal cancer are included in the Prospective Dutch ColoRectal Cancer (PLCRC) cohort study and give informed consent for collection of clinical data and biomaterials, including tissue and blood samples. Additionally, patients are invited to give their consent for future randomization without being informed when allocated to the control group receiving standard of care. In MEDOCC-CrEATE 1320 stage II colon cancer patients without an indication for ACT will be included and randomized 1:1 into an experimental and a control arm. In the experimental arm, tissue and blood samples are analyzed after surgery for tissue-informed detection of plasma ctDNA, using the PGDx elio™ Platform. Patients with detectable ctDNA after surgery will be offered ACT consisting of 8 cycles of capecitabine plus oxaliplatin. Patients in the experimental arm without detectable ctDNA and patients in the control arm receive standard follow-up. The primary endpoint is the proportion of patients accepting ACT when ctDNA is detectable after resection. Most important secondary endpoint is 2-year RR, but also includes 5-year RR, disease free and overall survival, time to recurrence, quality of life and cost-effectiveness of the ctDNA-based treatment strategy. Data will be analyzed by intention to treat. To our knowledge, MEDOCC-CrEATE is the first trial in which a ctDNA guided strategy for adjuvant chemotherapy in colon cancer is investigated. The first patient was enrolled in August 2020. MEDOCC-CrEATE is now open for inclusion in 8 hospitals in the Netherlands. So far, 9 patients have been randomized. The number of participating hospitals will be expanded to 20-25 hospitals to include all 1320 patients within 3 years. MEDOCC-CrEATE has been registered in the Netherlands Trial Register: NL6281/NTR6455.

Citation Format: Suzanna J. Schraa, Karlijn L. Van Rooijen, Dave E. Van Der Kruijssen, Carmen Rubio Alarcón, Jillian Phallen, John Simmons, Sam Angiuoli, Amy E. Greer, Veerle M. Coupé, Helma M. Van Grevenstein, Sjoerd Elias, Helena M. Verkooijen, Miranda M. Van Dongen, Linda J. Bosch, Daan Van Den Broek, Gerrit A. Meijer, Victor E. Velculescu, Remond J. Fijneman, Geraldine R. Vink, Miriam Koopman. MEDOCC-CrEATE trial in progress: effectiveness of adjuvant chemotherapy in stage II colon cancer patients with positive circulating tumor DNA [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT251.

Interaction Between Primary Tumor Resection, Primary Tumor Location, and Survival in Synchronous Metastatic Colorectal Cancer: A Population-Based Study

OBJECTIVES

Location of the primary tumor has prognostic value and predicts the effect of certain therapeutics in synchronous metastatic colorectal cancer. We investigated whether the association between primary tumor resection (PTR) and overall survival (OS) also depends on tumor location.

METHODS

Data on synchronous metastatic colorectal cancer patients from the Netherlands Cancer Registry (n=16,106) and Surveillance, Epidemiology, and End Results (SEER) registry (n=19,584) were extracted. Cox models using time-varying covariates were implemented. Median OS for right-sided colon cancer (RCC), left-sided colon cancer, and rectal cancer was calculated using inverse probability weighting and a landmark point of 6 months after diagnosis as reference.

RESULTS

The association between PTR and OS was dependent on tumor location (P<0.05), with a higher median OS of upfront PTR versus upfront systemic therapy in Netherlands Cancer Registry (NCR) of 1.9 (95% confidence interval: 0.9-2.8), 4.3 (3.3-5.6), and 3.4 (0.6-7.6) months in RCC, left-sided colon cancer and rectal cancer, respectively. In SEER data, the difference was 6.0 (4.0-8.0), 8.0 (5.0-10.0), and 10.0 (7.0-13.0) months, respectively. Hazard plots indicate a higher hazard of death 2 to 3 months after PTR in RCC.

CONCLUSION

Upfront PTR is associated with improved survival regardless of primary tumor location. Patients with RCC appear to have less benefit because of higher mortality during 2 to 3 months after PTR.

Early Cost-effectiveness Analysis of Risk-Based Selection Strategies for Adjuvant Treatment in Stage II Colon Cancer: The Potential Value of Prognostic Molecular Markers

BACKGROUND

To explore the potential value of consensus molecular subtypes (CMS) in stage II colon cancer treatment selection, we carried out an early cost-effectiveness assessment of a CMS-based strategy for adjuvant chemotherapy.

METHODS

We used a Markov cohort model to evaluate three selection strategies: (i) the Dutch guideline strategy (MSS+pT4), (ii) the mutation-based strategy (MSS plus a BRAF and/or KRAS mutation or MSS plus pT4), and (iii) the CMS-based strategy (CMS4 or pT4). Outcomes were number of colon cancer deaths per 1,000 patients, total discounted costs per patient (pp), and quality-adjusted life-years (QALY) pp. The analyses were conducted from a Dutch societal perspective. The robustness of model predictions was assessed in sensitivity analyses. To evaluate the value of future research, we performed a value of information (VOI) analysis.

RESULTS

The Dutch guideline strategy resulted in 8.10 QALYs pp and total costs of €23,660 pp. The CMS-based and mutation-based strategies were more effective and more costly, with 8.12 and 8.13 QALYs pp and €24,643 and €24,542 pp, respectively. Assuming a threshold of €50,000/QALY, the mutation-based strategy was considered as the optimal strategy in an incremental analysis. However, the VOI analysis showed substantial decision uncertainty driven by the molecular markers (expected value of partial perfect information: €18M).

CONCLUSIONS

On the basis of current evidence, our analyses suggest that the mutation-based selection strategy would be the best use of resources. However, the extensive decision uncertainty for the molecular markers does not allow selection of an optimal strategy at present.

IMPACT

Future research is needed to eliminate decision uncertainty driven by molecular markers.

Colorectal Cancer Care and Patients' Perceptions Before and During COVID-19: Implications for Subsequent SARS-CoV-2 Infection Waves

Background

Changes in colorectal cancer (CRC) care planning because of the coronavirus disease 2019 (COVID-19) pandemic and associated health-related quality of life (HRQoL) and well-being of patients with CRC are unknown. We report changes in CRC care and patient-reported outcomes including HRQoL, distress, and loneliness during the first wave of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Methods

In April 2020, 4984 patients included in the nationwide Prospective Dutch Colorectal Cancer cohort were invited to complete a COVID-19–specific questionnaire, together with the validated European Organisation for Research and Treatment of Cancer Core Quality of Life Questionnaire (QLQ-C30), De Jong Gierveld, and Hospital Anxiety and Depression Scale. Clinical data were obtained from the Netherlands Cancer Registry. Scores were compared with the year prior to COVID-19 and with an age- and sex-matched control population during COVID-19.

Results

In total, 3247 (65.1%) patients responded between April and June 2020. Of the patients, 17% had canceled, postponed, or changed hospital visits to a telephone or video consult, and 5.3% had adjusted, postponed, or canceled treatment. Compared with controls, patients reported worse HRQoL but comparable distress and less social loneliness (patients = 21.2%; controls = 32.9%). Compared with pre–COVID-19, clinically meaningful deterioration of HRQoL was more prevalent in patients with changes in cancer care planning than in patients without changes. Prior to undergoing or currently undergoing treatment and infection worries were associated with lower HRQoL.

Conclusions

CRC patients reported equal anxiety and depression but worse HRQoL than the control population. Changes in care planning were associated with deterioration of HRQoL and increased anxiety. In case of 1 or more risk factors, health-care specialists should discuss (mental) health status and possible support during future SARS-CoV-2 infection waves or comparable pandemics.

Model-based effectiveness and cost-effectiveness of risk-based selection strategies for adjuvant chemotherapy in Dutch stage II colon cancer patients

BACKGROUND

We aimed to evaluate the cost-effectiveness of risk-based strategies to improve the selection of surgically treated stage II colon cancer (CC) patients for adjuvant chemotherapy.

METHODS

Using the 'Personalized Adjuvant TreaTment in EaRly stage coloN cancer' (PATTERN) model, we evaluated five selection strategies: (1) no chemotherapy, (2) Dutch guideline recommendations assuming observed adherence, (3) Dutch guideline recommendations assuming perfect adherence, (4) biomarker mutation OR pT4 stage strategy in which patients with MSS status combined with a pT4 stage or a mutation in BRAF and/or KRAS receive chemotherapy assuming perfect adherence and (5) biomarker mutation AND pT4 stage strategy in which patients with MSS status combined with a pT4 stage tumor and a BRAF and/or KRAS mutation receive chemotherapy assuming perfect adherence. Outcomes were number of CC deaths per 1000 patients and total discounted costs and quality-adjusted life-years (QALYs) per patient (pp). Analyses were conducted from a societal perspective. The robustness of model predictions was assessed in sensitivity analyses.

RESULTS

The reference strategy, that is, no adjuvant chemotherapy, resulted in 139 CC deaths in a cohort of 1000 patients, 8.077 QALYs pp and total costs of €22,032 pp. Strategies 2-5 were more effective (range 8.094-8.217 QALYs pp and range 118-136 CC deaths per 1000 patients) and more costly (range €22,404-€25,102 pp). Given a threshold of €50,000/QALY, the optimal use of resources would be to treat patients with either the full adherence strategy and biomarker mutation OR pT4 stage strategy.

CONCLUSION

Selection of stage II CC patients for chemotherapy can be improved by either including biomarker status in the selection strategy or by improving adherence to the Dutch guideline recommendations.

Perceived Care and Well-being of Patients With Cancer and Matched Norm Participants in the COVID-19 Crisis: Results of a Survey of Participants in the Dutch PROFILES Registry

Importance

As the resolution of the coronavirus disease 2019 (COVID-19) crisis is unforeseeable, and/or a second wave of infections may arrive in the fall of 2020, it is important to evaluate patients' perspectives to learn from this.

Objective

To assess how Dutch patients with cancer perceive cancer treatment and follow-up care (including experiences with telephone and video consultations [TC/VC]) and patients' well-being in comparison with a norm population during the COVID-19 crisis.

Design, Setting, and Participants

Cross-sectional study of patients participating in the Dutch Patient Reported Outcomes Following Initial Treatment and Long-term Evaluation of Survivorship (PROFILES) registry and a norm population who completed a questionnaire from April to May 2020.

Main Outcomes and Measures

Logistic regression analysis assessed factors associated with changes in cancer care (treatment or follow-up appointment postponed/canceled or changed to TC/VC). Differences in quality of life, anxiety/depression, and loneliness between patients and age-matched and sex-matched norm participants were evaluated with regression models.

Results

The online questionnaire was completed by 4094 patients (48.6% response), of whom most were male (2493 [60.9%]) and had a mean (SD) age of 63.0 (11.1) years. Of these respondents, 886 (21.7%) patients received treatment; 2725 (55.6%) received follow-up care. Treatment or follow-up appointments were canceled for 390 (10.8%) patients, whereas 160 of 886 (18.1%) in treatment and 234 of 2725 (8.6%) in follow-up had it replaced by a TC/VC. Systemic therapy, active surveillance, or surgery were associated with cancellation of treatment or follow-up appointment. Younger age, female sex, comorbidities, metastasized cancer, being worried about getting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and receiving supportive care were associated with replacement of a consultation with a TC/VC. Patients and norm participants reported that the COVID-19 crisis made them contact their general practitioner (852 of 4068 [20.9%] and 218 of 979 [22.3%]) or medical specialist/nurse (585 of 4068 [14.4%] and 144 of 979 [14.7%]) less quickly when they had physical complaints or concerns. Most patients who had a TC/VC preferred a face-to-face consultation, but 151 of 394 (38.3%) were willing to use a TC/VC again. Patients with cancer were more worried about getting infected with SARS-CoV-2 compared with the 977 norm participants (917 of 4094 [22.4%] vs 175 of 977 [17.9%]). Quality of life, anxiety, and depression were comparable, but norm participants more often reported loneliness (114 of 977 [11.7%] vs 287 of 4094 [7.0%]) than patients with cancer (P = .009).

Conclusions and Relevance

Among patients with cancer in the Netherlands, 1 in 3 reported changes in cancer care in the first weeks of the COVID-19 crisis. Long-term outcomes need to be monitored. The crisis may affect the mental well-being of the general population relatively more than that of patients with cancer.

Longitudinal effects of adjuvant chemotherapy and related neuropathy on health utility in stage II and III colon cancer patients: A prospective cohort study

Patient's quality of life should be included in clinical decision making regarding the administration of adjuvant chemotherapy (ACT) in stage II/III colon cancer. Therefore, quality of life, summarized as health utility (HU), was evaluated for patients treated with and without ACT. Furthermore, the role of chemotherapy–induced peripheral neuropathy (CIPN) on HU was evaluated. Patients diagnosed with stage II/III colon cancer between 2011 and 2019 and participating in the Prospective Dutch ColoRectal Cancer cohort were included (n = 914). HU scores were assessed with the EQ‐5D‐5L at baseline, 3, 6, 12, 18, and 24 months. Patients treated with ACT received mainly capecitabine and oxaliplatin (57%) or capecitabine monotherapy (40%) (average duration: 3.5 months). HU 3 to 18 months after diagnosis (potential ACT period + 12 months follow‐up) was compared between patients treated with and without ACT using a mixed model adjusted for age, sex and education level. Subsequently, the CIPN sensory, motor and autonomy scales, measured using the EORTC QLQ‐CIPN20, were independently included in the model to evaluate the impact of neuropathy. Using a mixed model, a significant difference of −0.039 (95% confidence interval: −0.062; −0.015) in HU was found between patients treated with and without ACT. Including the CIPN sensory, motor and autonomy scales decreased the difference with 0.019, 0.015 and 0.02, respectively. HU 3 to 18 months after diagnosis is significantly lower in patients treated with ACT vs without ACT. This difference is on the boundary of clinical relevance and appears to be partly related to the sensory and motor neuropathy‐related side effects of ACT.

What's new?

Given its potentially serious side effects, patient quality of life should be included in clinical decision‐making regarding the administration of adjuvant chemotherapy in stage II/III colon cancer. Using a mixed model which was corrected for relevant covariates, here the authors found a statistically‐significant but small decrease in HU of −0.039 during chemotherapy and the following 12 months for patients treated with adjuvant chemotherapy compared to patients without adjuvant chemotherapy. The decrease in HU, which is on the boundary of clinical relevance, appears to be partly related to sensory and motor neuropathy side effects of adjuvant chemotherapy.

Model-based evaluation of the cost effectiveness of 3 versus 6 months' adjuvant chemotherapy in high-risk stage II colon cancer patients

BACKGROUND

Our aim was to evaluate the cost effectiveness of 3 months' adjuvant chemotherapy versus 6 months in high-risk (T4 stage + microsatellite stable) stage II colon cancer (CC) patients.

METHODS

Using the validated PATTERN Markov cohort model, which simulates the disease progression of stage II CC patients from diagnosis to death, we first evaluated a reference strategy in which high-risk patients were treated with chemotherapy for 6 months. In the second strategy, treatment duration was shortened to 3 months. Both strategies were evaluated for CAPOX (capecitabine plus oxaliplatin) and FOLFOX (fluorouracil, leucovorin and oxaliplatin). Based on trial data, we assumed that shortened treatment duration compared with a 6-month regimen was equally effective for CAPOX and less effective for FOLFOX. Adverse events were highest in the 6-month strategy. Analyses were conducted from a societal perspective using a lifelong time horizon. Outcomes were number of CC deaths per 1000 patients and total discounted costs and quality-adjusted life-years (QALYs) per patient (pp). Incremental net monetary benefit (iNMB) was calculated using a willingness-to-pay value of €50,000/QALY.

RESULTS

For CAPOX, the 6-month strategy resulted in 316 CC deaths per 1000 patients, 6.71 QALYs pp and total costs of €41,257 pp. The 3-month strategy resulted in an equal number of CC deaths, but higher QALYs (6.80 pp) and lower costs (€37,645 pp), leading to a iNMB of €8454 per person for 3 months versus 6 months. For FOLFOX, the 6-month strategy resulted in 316 CC deaths per 1000 patients, 6.71 QALYs pp and total costs of €47,135 pp. The 3-month strategy resulted in more CC deaths (393), lower QALYs (6.19 pp) and lower costs (€44,389 pp). An iNMB of -€23,189 was found for 3 months versus 6 months.

CONCLUSION

Our findings indicate that 3 months' adjuvant chemotherapy should be considered as standard of care in high-risk stage II CC patients for CAPOX, but not for FOLFOX.

Modeling Personalized Adjuvant TreaTment in EaRly stage coloN cancer (PATTERN)

AIM

To develop a decision model for the population-level evaluation of strategies to improve the selection of stage II colon cancer (CC) patients who benefit from adjuvant chemotherapy.

METHODS

A Markov cohort model with a one-month cycle length and a lifelong time horizon was developed. Five health states were included; diagnosis, 90-day mortality, death other causes, recurrence and CC death. Data from the Netherlands Cancer Registry were used to parameterize the model. Transition probabilities were estimated using parametric survival models including relevant clinical and pathological covariates. Subsequently, biomarker status was implemented using external data. Treatment effect was incorporated using pooled trial data. Model development, data sources used, parameter estimation, and internal and external validation are described in detail. To illustrate the use of the model, three example strategies were evaluated in which allocation of treatment was based on (A) 100% adherence to the Dutch guidelines, (B) observed adherence to guideline recommendations and (C) a biomarker-driven strategy.

RESULTS

Overall, the model showed good internal and external validity. Age, tumor growth, tumor sidedness, evaluated lymph nodes, and biomarker status were included as covariates. For the example strategies, the model predicted 83, 87 and 77 CC deaths after 5 years in a cohort of 1000 patients for strategies A, B and C, respectively.

CONCLUSION

This model can be used to evaluate strategies for the allocation of adjuvant chemotherapy in stage II CC patients. In future studies, the model will be used to estimate population-level long-term health gain and cost-effectiveness of biomarker-based selection strategies.

Circulating tumor DNA guided adjuvant chemotherapy in stage II colon cancer (MEDOCC-CrEATE): study protocol for a trial within a cohort study

BACKGROUND

Accurate detection of patients with minimal residual disease (MRD) after surgery for stage II colon cancer (CC) remains an urgent unmet clinical need to improve selection of patients who might benefit form adjuvant chemotherapy (ACT). Presence of circulating tumor DNA (ctDNA) is indicative for MRD and has high predictive value for recurrent disease. The MEDOCC-CrEATE trial investigates how many stage II CC patients with detectable ctDNA after surgery will accept ACT and whether ACT reduces the risk of recurrence in these patients.

METHODS/DESIGN

MEDOCC-CrEATE follows the 'trial within cohorts' (TwiCs) design. Patients with colorectal cancer (CRC) are included in the Prospective Dutch ColoRectal Cancer cohort (PLCRC) and give informed consent for collection of clinical data, tissue and blood samples, and consent for future randomization. MEDOCC-CrEATE is a subcohort within PLCRC consisting of 1320 stage II CC patients without indication for ACT according to current guidelines, who are randomized 1:1 into an experimental and a control arm. In the experimental arm, post-surgery blood samples and tissue are analyzed for tissue-informed detection of plasma ctDNA, using the PGDx elio™ platform. Patients with detectable ctDNA will be offered ACT consisting of 8 cycles of capecitabine plus oxaliplatin while patients without detectable ctDNA and patients in the control group will standard follow-up according to guideline. The primary endpoint is the proportion of patients receiving ACT when ctDNA is detectable after resection. The main secondary outcome is 2-year recurrence rate (RR), but also includes 5-year RR, disease free survival, overall survival, time to recurrence, quality of life and cost-effectiveness. Data will be analyzed by intention to treat.

DISCUSSION

The MEDOCC-CrEATE trial will provide insight into the willingness of stage II CC patients to be treated with ACT guided by ctDNA biomarker testing and whether ACT will prevent recurrences in a high-risk population. Use of the TwiCs design provides the opportunity to randomize patients before ctDNA measurement, avoiding ethical dilemmas of ctDNA status disclosure in the control group.

TRIAL REGISTRATION

Netherlands Trial Register: NL6281/NTR6455 . Registered 18 May 2017, https://www.trialregister.nl/trial/6281.

Improving clinical management of colon cancer through CONNECTION, a nation-wide colon cancer registry and stratification effort (CONNECTION II trial): rationale and protocol of a single arm intervention study

BACKGROUND

It is estimated that around 15-30% of patients with early stage colon cancer benefit from adjuvant chemotherapy. We are currently not capable of upfront selection of patients who benefit from chemotherapy, which indicates the need for additional predictive markers for response to chemotherapy. It has been shown that the consensus molecular subtypes (CMSs), defined by RNA-profiling, have prognostic and/or predictive value. Due to postoperative timing of chemotherapy in current guidelines, tumor response to chemotherapy per CMS is not known, which makes the differentiation between the prognostic and predictive value impossible. Therefore, we propose to assess the tumor response per CMS in the neoadjuvant chemotherapy setting. This will provide us with clear data on the predictive value for chemotherapy response of the CMSs.

METHODS

In this prospective, single arm, multicenter intervention study, 262 patients with resectable microsatellite stable cT3-4NxM0 colon cancer will be treated with two courses of neoadjuvant and two courses of adjuvant capecitabine and oxaliplatin. The primary endpoint is the pathological tumor response to neoadjuvant chemotherapy per CMS. Secondary endpoints are radiological tumor response, the prognostic value of these responses for recurrence free survival and overall survival and the differences in CMS classification of the same tumor before and after neoadjuvant chemotherapy. The study is scheduled to be performed in 8-10 Dutch hospitals. The first patient was included in February 2020.

DISCUSSION

Patient selection for adjuvant chemotherapy in early stage colon cancer is far from optimal. The CMS classification is a promising new biomarker, but a solid chemotherapy response assessment per subtype is lacking. In this study we will investigate whether CMS classification can be of added value in clinical decision making by analyzing the predictive value for chemotherapy response. This study can provide the results necessary to proceed to future studies in which (neo) adjuvant chemotherapy may be withhold in patients with a specific CMS subtype, who show no benefit from chemotherapy and for whom possible new treatments can be investigated.

TRIAL REGISTRATION

This study has been registered in the Netherlands Trial Register (NL8177) at 11-26-2019, https://www.trialregister.nl/trial/8177 . The study has been approved by the medical ethics committee Utrecht (MEC18/712).

Abstract 3096: Liquid biopsy cell-free circulating tumor DNA as prognostic biomarker for stage III colon cancer patients

Introduction: Stage III colon cancer patients undergo surgery followed by adjuvant chemotherapy (ACT) according to clinical guidelines. However, 50% would be cured by surgery alone and are being overtreated, while 30-35% will relapse despite adjuvant treatment. This means that only 15-20% of the patients benefit from ACT. Therefore, there is a need for better prognostic biomarkers to stratify patients for ACT. Detection of cell-free circulating tumor DNA (ctDNA) in blood after surgery is indicative of minimal residual disease and highly prognostic for disease recurrence. Hence, detecting liquid biopsy ctDNA is a promising approach to guide treatment decisions in stage III colon cancer.

Aim: Determine prognostic value of ctDNA in stage III colon cancer patients treated with ACT in order to reduce futile treatment.

Methods: 315 stage III colon cancer patients treated with ACT will be included in the prospective observational study “PROVENC3” (PROgnostic Value of Early Notification by Ctdna in Colon Cancer stage 3). The Prospective Dutch Colorectal Cancer Cohort (PLCRC) infrastructure organizes accrual of colorectal cancer patients in more than 50 hospitals in the Netherlands, among which 25 hospitals that accrue patients for PROVENC3. If informed consent is provided, blood is collected at baseline, post-surgery, post-ACT and every six months up to 3 years, and shipped to a central location. Tumor-informed detection of mutations in ctDNA will be performed by combined analysis of targeted sequencing of a panel of &gt;30 genes in cfDNA (PGDx elio plasma test) and a panel of &gt;500 genes in DNA from formalin-fixed paraffin-embedded tumor tissue (PGDx elio tissue complete assay). The clinical, pathological, and molecular data will be handled according to the FAIR (findable, accessible, interoperable and reusable) principles and integrated in cBioPortal.

Results and future directions: Around 125 patients and 400 blood samples included to date. Once sequencing data are obtained we will determine: 1) the proportion of ctDNA-positive and ctDNA-negative patients after surgery and the corresponding recurrence rates; 2) the prognostic value of ctDNA pre-surgery; and 3) the lead time between ctDNA detection and recurrence. Ultimately, the results of this study will be used to model and design an ethically acceptable and cost-effective ctDNA-guided interventional trial, to reduce futile ACT and its associated side-effects in stage III colon cancer patients.

Citation Format: Carmen Rubio Alarcón, Dave E. van der Kruijssen, Lana Meiqari, Linda J. Bosch, John K. Simmons, Victor E. Velculescu, Daan van den Broek, Cornelis J. Punt, Veerle M. Coupé, Miriam Koopman, Gerrit A. Meijer, Geraldine R. Vink, Remond J. Fijneman. Liquid biopsy cell-free circulating tumor DNA as prognostic biomarker for stage III colon cancer patients [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3096.

Informing metastatic colorectal cancer patients by quantifying multiple scenarios for survival time based on real-life data

Reported median overall survival (mOS) in metastatic colorectal cancer (mCRC) patients participating in systemic therapy trials has increased to over 30 months. It is uncertain whether trial results translate to real-life populations. Moreover, patients prefer presentation of multiple survival scenarios. Population-based data of all stage IV CRC patients diagnosed between 2008 and 2016 were obtained from the Netherlands Cancer Registry, which has a case ascertainment completeness surpassing 95%. We calculated the following percentiles (scenarios) of OS per year of diagnosis for the total population, and for treatment subgroups: 10th (best-case), 25th (upper-typical), 50th (median), 75th (lower-typical) and 90th (worst-case). Twenty-five percent of patients did not receive any antitumor treatment. From 2008 to 2016, mOS of the total population (n = 27275) remained unchanged at approximately 12 months. OS improved only for the upper-typical and best-case patients; by 4.2 to 29.1 months (P < .001), and by 6 to 62 months (P < .001), respectively. No clinically relevant change was observed among patients who received systemic therapy, with mOS close to 15 months and best-case scenario approximately 40 months. A clinically relevant improvement in survival over time was observed in patients who initially received metastasectomy and/or HIPEC only. In contrast to the wide belief based on trial data that mOS of mCRC patients receiving systemic therapy has improved substantially, improvement could not be demonstrated in our real-life population. Clinicians should consider quoting multiple survival scenarios based on real-life data instead of point estimates from clinical trials, when informing patients about their life expectancy.

Performance of four platforms for KRAS mutation detection in plasma cell-free DNA: ddPCR, Idylla, COBAS z480 and BEAMing

Multiple platforms are commercially available for the detection of circulating cell-free tumour DNA (ctDNA) from liquid biopsies. Since platforms have different input and output variables, deciding what platform to use for a given clinical or research question can be daunting. This study aimed to provide insight in platform selection criteria by comparing four commercial platforms that detect KRAS ctDNA hotspot mutations: Bio-Rad droplet digital PCR (ddPCR), BioCartis Idylla, Roche COBAS z480 and Sysmex BEAMing. Platform sensitivities were determined using plasma samples from metastatic colorectal cancer (mCRC) patients and synthetic reference samples, thereby eliminating variability in amount of plasma analysed and ctDNA isolation methods. The prevalence of KRAS nucleotide alterations was set against platform-specific breadth of target. Platform comparisons revealed that ddPCR and BEAMing detect more KRAS mutations amongst mCRC patients than Idylla and COBAS z480. Maximum sample throughput was highest for ddPCR and COBAS z480. Total annual costs were highest for BEAMing and lowest for Idylla and ddPCR. In conclusion, when selecting a platform for detection of ctDNA hotspot mutations the desired test sensitivity, breadth of target, maximum sample throughput, and total annual costs are critical factors that should be taken into consideration. Based on the results of this study, laboratories will be able to select the optimal platform for their needs.

The Prospective Dutch Colorectal Cancer (PLCRC) Cohort: Towards a unique patient-reported outcome enriched “real-world” data cohort

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Background: The initiation of high-quality pan-population cohort studies is a major research priority for the improvement of colorectal cancer (CRC) outcomes as advocated by regulators and the research community. In 2013, the PLCRC cohort of the Dutch Colorectal Cancer Group was initiated in which longitudinal clinical data and patient-reported outcomes (PRO) are collected, along with pathology data and biospecimens, to serve as an infrastructure for a broad body of observational and (randomized) interventional research. Here we report on the cohort’s progress and investigate whether it develops in the direction of a nation-wide cohort of “real-world” nature. Methods: Clinical and demographical data of PLCRC participants, as prospectively collected in the Netherlands Cancer Registry by qualified data managers, were compared with the total Dutch CRC population with incidence between 2013-2017 (ref. population) which was also obtained from the Netherlands Cancer Registry. Variable distributions are compared using t-tests and χ2-tests, whereas cohort characteristics are descriptive. Results: In June 2019, 5,746 patients were enrolled in 52 / 75 Dutch hospitals, and 81% consented to receive repeated PROs. Compared to patients enrolled between 2013-16 (N = 1,093, 1-17 recruiting hospitals), we found a small shift towards the Dutch ref. population (N = 74,692) for patients enrolled between 2017-19 (N = 4,653, 17-52 hospitals) in terms of age at diagnosis (mean 64.6±10.2 years in 2013-16, 65.2±10.8 in 2017-19, and 69.5±10.9 in the ref. group), sex (65% males in 2013-16, 61% in 2017-19, and 56% in the ref. population), location of primary tumor (56% rectum in 2013-16, 40% in 2017-19, and 31% in the ref. population) and TNM stage (35% stage I-II in 2013-16, 41% in 2017-19, and 48% in the population). Conclusions: Over the past years, the number of PLCRC recruiting centers and participating patients, with high consent rates for PROs, steeply increased. Further improvements in recruitment methodologies and multidisciplinary enrolment of patients will continue to enhance PLCRC’s representation of the “real-world” and its ability to supplement trial-based evidence.

Informing metastatic colorectal cancer patients by quantifying multiple scenarios for survival based on real-life data

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Background: Reported median overall survival (mOS) in trials of metastatic colorectal cancer (mCRC) patients receiving systemic therapy has increased to over 30 months. When informing patients, many clinicians quote the mOS reported in these trials. It is uncertain whether trial results translate to real-life populations. Moreover, patients prefer presentation of multiple survival scenarios over presentation of just mOS. Therefore, we quantified multiple scenarios for survival time of real-life mCRC patients. Methods: Nationwide population-based data of all stage IV CRC patients diagnosed between 2008 and 2016 were obtained from the Netherlands Cancer Registry. We calculated percentiles (scenarios) of OS per year of diagnosis for the total population, and for treatment subgroups: 10th (best-case), 25th (upper-typical), 50th (median), 75th (lower-typical), and 90th (worst-case). Results: The total study population comprised 27,275 patients. Twenty-five percent these patients did not receive any antitumor treatment. From 2008-2016, mOS of the total population remained unchanged at approximately 12 months. OS improved only for the upper-typical and best-case patients; by 4.2 to 29.1 months (p<0.001), and by 6.0 months to 62.0 months (p<0.001), respectively. No clinically relevant change was seen among patients who received systemic therapy, with mOS close to 15 months and best-case scenario approximately 40 months. mOS and worst-case scenario for survival were highest in patients who underwent both metastasectomy and systemic therapy: around 48 and 15 months, respectively. A clinically relevant improvement in survival over time was observed only in patients who initially received metastasectomy without systemic treatment. Conclusions: In contrast to the wide belief that mOS of mCRC patients receiving systemic therapy has improved substantially, improvement could not be demonstrated in our real-life population. Clinicians should consider quoting multiple scenarios for survival based on real-life data, instead of point estimates from clinical trials, when informing patients about their life expectancy.

Estimating adjuvant treatment effects in Stage II colon cancer: Comparing the synthesis of randomized clinical trial data to real-world data

There is an ongoing discussion regarding the impact of adjuvant chemotherapy in Stage II colon cancer. We therefore estimated adjuvant treatment effect in Stage II colon cancer using pooled disease‐free survival (DFS) data from randomized clinical trials (RCT approach) and compared this to real‐world data (RWD approach) estimates. First, we estimated the treatment effect in RCTs by (i) searching relevant trials reporting DFS data, (ii) generating patient‐level data from reported DFS data and (iii) estimating treatment effect in the patient‐level data. Second, the treatment effect was estimated in an observational cohort of 1,947 patients provided by the Netherlands Cancer Registry using three propensity score methods; matching, weighting and stratification. In the RCT approach, patient‐level data of 4,489 patients (events: 853) were generated from seven trials which compared two of the following treatment arms: control, 5FU/LV or FOLFOX. A Cox model was used to estimate a hazard ratio (HR) of 0.77 (0.43;1.10) for 5FU/LV vs. control and 0.93 (0.72;1.15) for FOLFOX vs. 5FU/LV. In the RWD approach, HRs for any adjuvant treatment vs. control were 0.95 (0.50;1.80), 0.88 (0.24;3.21) and 1.05 (0.04;2.06) using matching, weighting and stratification, respectively. There was no significant difference with the estimates from the RCT approach (interaction test, p > 0.10). The RCT data suggest a clinically relevant benefit of adjuvant chemotherapy in terms of DFS, but the estimate did not reach statistical significance. Stratified analyses are required to evaluate whether treatment effect differs in specific subgroups.

What's new?

There is an ongoing discussion regarding the impact of adjuvant chemotherapy in stage II colon cancer. This study presents the most recent pooled estimate based on available RCT data since 1999, resulting in a pooled hazard ratio of 0.77 (95% CI 0.43;1.10) for fluoropyrimidine compared to no treatment. Even though no significant treatment effect was found, neither in the RCT approach nor in the real‐world data approach, the RCT data suggest a clinically‐relevant benefit of adjuvant chemotherapy. To improve guidance in treatment decisions, larger sample sizes, pooling of true patient‐level data with covariate information, and subgroup specific analyses are required.

Abstract 2276: Performance and cost comparison of circulating tumor DNA detection platforms

Purpose

The field of circulating cell free DNA (cfDNA) testing is quickly developing. Multiple platforms to detect hotspot mutations in ctDNA are available, including Bio-Rad droplet digital PCR (ddPCR), BioCartis Idylla, Roche COBAS z480 and Sysmex BEAMing. These platforms vary in the amount of plasma required, the method of ctDNA isolation, the number of hotspots analyzed, and the costs per sample. These factors can impact the applicability of a specific platform in the analysis of ctDNA.

In this study we compared these platforms in terms of sensitivity and total costs per sample.

Methods

The platform comparison was performed as follows:

1. Plasma from six metastatic colorectal cancer (mCRC) patients with known tissue KRAS mutation status was analyzed according to the manufacturers’ protocols.

2. Sensitivity was tested using six constructed reference samples with seven KRAS hotspot mutations at various total input (10ng, 50ng) and mutant allele frequencies (0%, 0.04%, 0.50%); each in four replicates.

3. Twelve mCRC patients were analyzed using equal amounts of ctDNA for each platform.

4. Total costs per sample were evaluated, including costs for consumables, technician hands-on time, equipment and maintenance.

Results

1. In six mCRC samples BEAMing (3ml plasma) detected 5/6 mutations, ddPCR and Idylla (both 1ml plasma) 4/6 mutations and COBAS z480 (2ml plasma) 3/6 mutations.

2. In constructed reference samples ddPCR (65%) and BEAMing (46%) yielded the highest sensitivity. With 10ng input BEAMing and COBAS z480 produced “Too little DNA” errors in 60% and 100% of cases, respectively.

3. In twelve mCRC samples, eight had more than 10ng ctDNA and four had less. All platforms were fully concordant for samples with more than 10ng input. Detection rate across twelve samples: Idylla detected 7/11 detectable mutations, COBAS z480 and BEAMing both detected 5/11, ddPCR detected 4/10.

4. BEAMing has the highest cost per sample (€486-€821) whereas ddPCR has the lowest cost per sample (€39-€298).

Conclusions

A direct comparison of ctDNA mutation detection platforms is complex and should take into account the differences in input and output specifications of the platforms.

Factors such as complexity of analysis (Idylla is a low complexity platform, whereas BEAMing requires more specialized training), total costs (varying from ddPCR to BEAMing), sensitivity (ddPCR and BEAMing yielded the highest sensitivity) and the number of mutations evaluated vary greatly between the platforms. All these factors influence ctDNA analysis and will have to be considered when choosing a specific platform for a specific (clinical) question, or when comparing results between studies.

Our data provide insight in the comparative performance of four commercial ctDNA analysis platforms, allowing future users to make an informed decision regarding a platform.

Acknowledgement

Powered by Health~Holland, Top Sector Life Sciences & Health, grant LSHM16047-H005.

Citation Format: Daan C. Vessies, Marjolein J. Greuter, Karlijn L. van Rooijen, Theodora C. Linders, Mirthe Lanfermeijer, Kalpana L. Ramkisoensing, Flore E. Grijseels, Boris van Doorn, Gerrit A. Meijer, Miriam Koopman, Veerle M. Coupé, Geraldine R. Vink, Remond J. Fijneman, Daan van den Broek. Performance and cost comparison of circulating tumor DNA detection platforms [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2276.

Recent changes in overall survival of real-life stage IV colorectal cancer patients

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Background: In the past decade, the reported median overall survival (mOS) in phase 3 trials of metastatic colorectal cancer (mCRC) patients increased from approximately 16 to over 36 months. However, only 2.5-20% of cancer patients participate in clinical studies and these are often patients with favourable prognostic factors. Therefore, we explored for which proportion of real-life stage IV CRC patients OS improved in recent years. Methods: Nationwide population-based data of all stage IV (synchronous metastatic) CRC patients diagnosed between 2008-2016 in the Netherlands who received local and/or systemic antitumor therapy were obtained from the Netherlands Cancer Registry (NCR). Initial treatment was registered in the NCR. Vital status was recorded until January 31st 2018. OS per incidence year was determined for various percentiles, which represent the number of months after which 10-30-50-70-80-90% of the patients had died. For some percentiles survival time exceeded follow-up duration. Results: The total study population comprised 21,047 patients. mOS remained unchanged in the period 2008-2016 at around 15 months. OS of p10 and p30 increased by 1,5 months to 3,6 and 10,0 respectively. For the ‘best’ (longest-living) patients (p70-p80) OS improved in the period 2008-2016 by 4 and 6 months to 30 and 43 months, respectively. Follow-up duration is insufficient to analyse change over time for the 10% ‘best’ patients. mOS did not change for any of the treatment subgroups except for the patients who received exclusively non-systemic therapy (e.g. metastasectomy, radiotherapy) in which mOS improved by 11 months to almost 20 months. Conclusions: mOS of real-life stage IV CRC patients has not improved since 2008. We observed a clinically relevant survival improvement in only 30% of all treated patients and in all patients who received exclusively non-systemic therapy. These data illustrate the different outcomes between trial patients and total patient population, which emphasizes that trial patients represent a selection of patients with favourable prognosis. Our results highlight the value of real-life data to determine efficacy of innovations in daily clinical practice.