OUP accepted manuscript

Background

The survival impact of multi-agent (MAC) compared with single-agent (SAC) adjuvant chemotherapy (AC) in elderly patients with stage III colon cancer (CC) remains controversial. The aim of this study was to compare survival outcomes of MAC and SAC in this population utilizing the National Cancer Database (NCDB).

Patients and Methods

Patients aged ≥70 years with pathological stage III CC diagnosed in 2004-2015 were identified in the NCDB. Univariate and multivariable analyses were conducted, and Kaplan-Meier analysis and Cox proportional hazard models were used to identify associations between MAC vs. SAC and overall survival (OS).

Results

Among 41 707 elderly patients (≥70 years old) with stage III CC, about half (n = 20 257; 48.5%) received AC; the majority (n = 12 923, 63.8%) received MAC. The median age was 79 (range 70-90). The majority were female (n = 11 201, 55.3%), Caucasians (88%) and had moderately differentiated tumor grade (n = 12 619, 62.3%), tumor size >4 cm (11 785, 58.2%), and negative surgical margins (18 496, 91.3%). Low-risk stage III CC constituted 50.6% (n = 10 264) of the study population. High-risk stage III CC was associated with worse OS compared with low-risk disease (HR 0.35, 0.34-0.36, P < .001). Multi-agent chemotherapy was associated with a better 5-year OS compared with SAC (P < .001). High-risk stage III patients who received MAC vs. SAC had an OS of 4.2 vs. 3.4 years, respectively (P < .001). Low-risk stage III patients who received MAC vs. SAC had a median OS of 8.5 vs. 7 years (P < .001). In univariate and multivariable analyses, male sex, positive surgical margin, insurance and facility types, age, year of diagnosis, tumor size, and Charlson-Deyo score of >2 were associated with worse OS (P < .05).

Conclusions

Any adjuvant chemotherapy has a trend of survival benefits. Multi-agent chemotherapy seems to have an enhanced benefit in the 70-75 age group. Multi-agent chemotherapy seemed to have similar efficacy as SAC in those aged >76 years.

Hyaluronic Acid May Be a Predictive Biomarker for Thrombocytopenia and Liver Dysfunction After Oxaliplatin-based Chemotherapy

BACKGROUND/AIM

Following oxaliplatin-based chemotherapy, approximately half of all colorectal cancer patients develop sinusoidal obstruction syndrome (SOS). SOS can be monitored by measuring splenic volume; however, obtaining this measurement is not a simple process. In this study, we evaluated changes in hyaluronic acid (HA) concentrations as a simpler marker of SOS.

PATIENTS AND METHODS

We measured splenic volume and laboratory data, including hyaluronic acid concentration, liver enzymes, and platelet counts, in 34 patients with colorectal cancer who underwent radical resection and who received capecitabine plus oxaliplatin (CapeOx) chemotherapy.

RESULTS

A strong correlation was identified between ≥30% increase in splenic volume and significantly elevated HA concentrations. Affected patients also had persistent thrombocytopenia and liver dysfunction compared to patients without elevated HA concentration.

CONCLUSION

HA concentration may predict SOS in patients who receive CapeOx adjuvant chemotherapy.

Effectiveness of oral fluoropyrimidine monotherapy as adjuvant chemotherapy for high-risk stage II colon cancer

Purpose

Methods

Results

Conclusion

Clinical implication of adjuvant chemotherapy according to mismatch repair status in patients with intermediate-risk stage II colon cancer

Background

The present study evaluated the clinical implications of adjuvant chemotherapy according to the mismatch repair (MMR) status and clinicopathologic features of patients with intermediate- and high-risk stage II colon cancer (CC).

Methods

This study retrospectively reviewed 5,774 patients who were diagnosed with CC and underwent curative surgical resection at Kyungpook National University Chilgok Hospital. The patients were enrolled according to the following criteria: (1) pathologically diagnosed with primary CC; (2) stage II CC classified based on the 7th edition of the American Joint Committee on Cancer staging system; (3) intermediate- and high-risk features; and (4) available test results for MMR status. A total of 286 patients met these criteria and were included in the study.

Results

Among the 286 patients, 54 (18.9%) were identified as microsatellite instability-high (MSI-H) or deficient MMR (dMMR). Although all the patients identified as MSI-H/dMMR showed better survival outcomes, T4 tumors and adjuvant chemotherapy were identified as independent prognostic factors for survival. For the intermediate-risk patients identified as MSI-low (MSI-L)/microsatellite stable (MSS) or proficient MMR (pMMR), adjuvant chemotherapy exhibited a significantly better disease-free survival (DFS) but had no impact on overall survival (OS). Oxaliplatin-containing regimens showed no association with DFS or OS. Adjuvant chemotherapy was not associated with DFS in intermediate-risk patients identified as MSI-H/dMMR.

Conclusion

The current study found that the use of adjuvant chemotherapy was correlated with better DFS in MSI-L/MSS or pMMR intermediate-risk stage II CC patients.

In vitro and in vivoactivity of series of cationic dinuclearPt(II) complexes

The antitumour potential of nine dinuclear platinum(II) complexes of the type [{Pt(L)Cl}2(μ-X)]2+(where L represents two NH3 or different bidentantly coordinated diamine ligand - ethylenediamine, en; (±)-1,2-propylenediamine, 1,2-pn; isobutylenediamine, ibn; trans-(±)-1,2-diaminocyclohexane, dach; 1,3-propylenediamine, 1,3-pd; 2,2-dimethyl-1,3-propylenediamine, 2,2-diMe-1,3-pd; (±)-1,3-pentanediamine,1,3-pnd, and X is a bridging pyrazine (pz) or pyridazine (pydz) ligand) were determined by in vitro and in vivo assays using the CT26 cell line and a murine model of heterotopic colon cancer tumour induced in immunocompetent BALB/c mice. This study concludes that complexes Pt1, Pt2 and Pt7 possess significant in vitro cytotoxic activity against mouse colon carcinoma CT26 cells, while all these complexes show moderate apoptotic effect. Complexes Pt1 and Pt7 arrested CT26 cells in G2/M phase of cell cycle, while, evaluated by detection of Ki67 expressing cells, complexes Pt5 and Pt6 exerted the highest antiproliferative effect. Complexes Pt1 and Pt2 exerted significant in vivo antitumour effects. These complexes reduced the growth of primary tumour and the incidence of lung and liver metastases without causing the significant hepato- and nephro- toxicity. Our data indicate considerable antitumour activity of platinum(II) complexes against CT26 cells in vitro and in vivo and imply possible further investigations on their role as potential chemotherapeutic agents.

Detecting Liquid Remnants of Solid Tumors: Circulating Tumor DNA Minimal Residual Disease

Growing evidence demonstrates that circulating tumor DNA (ctDNA) minimal residual disease (MRD) following treatment for solid tumors predicts relapse. These results suggest that ctDNA MRD could identify candidates for adjuvant therapy and measure response to such treatment. Importantly, factors such as assay type, amount of ctDNA release, and technical and biological background can affect ctDNA MRD results. Furthermore, the clinical utility of ctDNA MRD for treatment personalization remains to be fully established. Here, we review the evidence supporting the value of ctDNA MRD in solid cancers and highlight key considerations in the application of this potentially transformative biomarker.

SIGNIFICANCE

ctDNA analysis enables detection of MRD and predicts relapse after definitive treatment for solid cancers, thereby promising to revolutionize personalization of adjuvant and consolidation therapies.

Predictive risk-score model for selection of patients with high-risk stage II colon cancer for adjuvant systemic therapy

BACKGROUND

Adjuvant systemic therapy is selectively considered for high-risk stage II colon cancer, but which patients benefit most from adjuvant systemic therapy is unclear.

METHODS

Patients who underwent resection of stage II colon cancer were identified from the National Cancer Database (2010-2016). Risk-factors for decreased overall survival on multivariable analysis were used to establish a predictive risk-score model for all-cause mortality. After propensity matching within each risk group, 5-year overall survival was estimated based on receipt of adjuvant systemic therapy.

RESULTS

Of the 15,241 patients evaluated, 2,857 (18.8%) received adjuvant systemic therapy. Risk factors for decreased overall survival included age >75 (hazard ratio 3.3, P < .001), male sex (hazard ratio 1.2, P < .001), White/Black race (hazard ratio 1.4, P = .020), preoperative carcinoembryonic antigen >3.5 ng/mL (hazard ratio 1.6, P < .001), T4a T-stage (hazard ratio 2.0, P < .001), T4b T-stage (hazard ratio 2.4, P < .001), lymphovascular invasion (hazard ratio 1.2, P = .003), perineural invasion (hazard ratio 1.3, P = .003), and non-R0 proximal/distal resection margins (hazard ratio 1.7, P < .001). An internally validated risk-score model using these factors was developed composed of low-risk (n = 8,489), moderate-risk (n = 4,623), and high-risk (n = 2,129) groups; within each group, 19.9%, 15.7%, and 20.8% of patients, respectively, received adjuvant systemic therapy. After propensity matching, adjuvant systemic therapy was not associated with improved 5-year overall survival for low-risk patients (89.8% vs 88.3%, P = .280), but was for moderate-risk (80.5% vs 70.8%, P < .001), and high-risk (65.2% vs 45.7%, P < .001) patients.

CONCLUSION

A predictive risk-score model incorporating patient and tumor factors identifies a high-risk cohort of stage II colon cancer patients who may benefit from adjuvant systemic therapy, although the minority of these patients appear to be receiving treatment.

Clinicopathological and Molecular Characteristics of Early-Onset Stage III Colon Adenocarcinoma: An Analysis of the ACCENT Database

BACKGROUND

Colon cancer (CC) incidence in young adults (age 20-49 years), termed early-onset CC (EO-CC), is increasing.

METHODS

Individual patient data on 35 713 subjects with stage III colon cancer from 25 randomized studies in the Adjuvant Colon Cancer ENdpoint database were pooled. The distributions of demographics, clinicopathological features, biomarker status, and outcome data were summarized by age group. Overall survival, disease-free survival, time to recurrence, and survival after recurrence were assessed by Kaplan-Meier curves and Cox models stratified by treatment arms within studies, adjusting for sex, race, body mass index, performance status, disease stage, grade, risk group, number of lymph nodes examined, disease sidedness, and molecular markers. All statistical tests were 2-sided.

RESULTS

Using a 5% difference between age groups as the clinically meaningful cutoff, patients with stage III EO-CC had similar sex, race, performance status, risk group, tumor sidedness, and T stage compared with patients with late-onset CC (age 50 years and older). EO-CC patients were less likely to be overweight (30.2% vs 36.2%) and more commonly had 12 or more lymph nodes resected (69.5% vs 58.7%). EO-CC tumors were more frequently mismatch repair deficient (16.4% vs 11.5%) and less likely to have BRAFV600E (5.6% vs 14.0%), suggesting a higher rate of Lynch syndrome in EO-CC. Patients with EO-CC had statistically significantly better overall survival (hazard ratio [HR] = 0.81, 95% confidence interval [CI] = 0.74 to 0.89; P < .001), disease-free survival (HR = 0.91, 95% CI = 0.84 to 0.98; P = .01), and survival after recurrence (HR = 0.88, 95% CI = 0.80 to 0.97; P = .008) in the analysis without molecular markers; however, age at onset of CC lost its prognostic value when outcome was adjusted for molecular markers.

CONCLUSION

Tumor biology was found to be a more important prognostic factor than age of onset among stage III colon cancer patients in the Adjuvant Colon Cancer ENdpoint database.

Adjuvant treatment of colon cancer with microsatellite instability - the state of the art

Adjuvant chemotherapy with fluoropyrimidine (FP) plus oxaliplatin in stage III resected colorecatal cancer (RCRC) resulted in a 30% relative reduction of disease recurrence risk and mortality. The presence of altered mismatch repair genes identify tumors with microsatellite instability (MSI) that have a better prognosis than stable tumors, but data about adjuvant chemotherapy benefit in this subgroup are compelling. We investigate the role of adjuvant therapy in resected MSI RCRC. The standard treatment is the association of FP plus oxaliplatin, while it can avoided in low risk stage II, thanks to its good prognosis. We propose a practice strategy to approach MSI RCRC in line with the current knowledge. In consideration of the dramatic results in chemorefractory MSI metastatic CRC, there are assumptions that immunotherapy can become a potential alternative to classical systemic therapies also in the adjuvant setting. We await the results of ongoing studies to draw further conclusions."

Outcomes of Cytoreduction and Oxaliplatin-Based Hyperthermic Intraperitoneal Chemotherapy in Patients With Peritoneal Carcinomatosis From Colorectal Cancer

Among patients with metastatic colorectal cancer, 25% have isolated peritoneal carcinomatosis. We performed a systematic review and meta-analysis to assess the disease-free survival (DFS) and overall survival (OS) of patients undergoing hyperthermic intraperitoneal chemotherapy with oxaliplatin. Eleven studies were included in the final assessment. Pooled three- and five-year OS rates were 58.60% and 42.19%, respectively. The estimated pooled three- and five-year DFS rates were 23.47% and 14.26%, respectively.

[Neoadjuvant and adjuvant therapy of resectable colon cancer - Current standards and developments]

The present review focusses on perioperative diagnosis and treatment of resectable colon cancer. In UICC stages associated with a higher risk of recurrence, adjuvant chemotherapy after resection of the primary tumor is an established standard. While initial data also indicate the benefit of Neoadjuvant, pre-operative chemotherapy, a final evaluation is still pending. The main focus of molecular testing in the perioperative setting is the analysis of microsatellite instability, which should routinely be performed in defined subgroups. In UICC stage II without risk factors, adjuvant therapy has a limited benefit and therefore is not a preferred option. In UICC stage II with risk factors, adjuvant therapy can be performed. The approach here is based on the recommendations applicable to stage III. In UICC stage III with low risk, adjuvant chemotherapy with CAPOX for 3 months is preferentially recommended. In UICC stage III with high risk, adjuvant chemotherapy over 6 months is recommended, preferentially with FOLFOX. Microsatellite instability (MSI) is clearly associated with favorable prognosis in non-metastatic colon cancer. However, it cannot be considered a predictive factor for the efficacy of adjuvant chemotherapy. Specifically, recent data of the IDEA study have opened the arena for shared decision making between physicians and patients allowing to define individual treatment approaches based on common assessment of risks and benefits. After completion of perioperative treatment, structured follow-up is of great importance and should be carried out according to the recommendations of the S3 guideline.

Circulating Tumour DNA and Colorectal Cancer: the Next Revolutionary Biomarker?

PURPOSE OF REVIEW

Improving outcomes for patients with colorectal cancer in both the adjuvant and metastatic setting has been challenging. Here, we review the current and future directions for using ctDNA in clinical practice.

RECENT FINDINGS

Circulating tumour DNA (ctDNA) with its ability to detect minimal residual disease is beginning to refine the way we assess recurrence risk in the adjuvant setting. We can potentially tailor treatments to reduce recurrence risk and minimize treatment toxicity. In the metastatic setting, ctDNA can provide a less invasive method of detecting clinically important genetic changes to guide molecularly targeted treatment and to identify mechanisms of molecular resistance. ctDNA can be a surrogate marker for treatment response and help guide the timing of anti-EGFR rechallenge. We await the results of the randomized clinical trials assessing clinical utility of ctDNA in both the adjuvant and metastatic setting before incorporating ctDNA into clinical practice.

Gene Therapy Targeting p53 and KRAS for Colorectal Cancer Treatment: A Myth or the Way Forward?

Colorectal cancer (CRC) is the third most commonly diagnosed malignancy worldwide and is responsible as one of the main causes of mortality in both men and women. Despite massive efforts to raise public awareness on early screening and significant advancements in the treatment for CRC, the majority of cases are still being diagnosed at the advanced stage. This contributes to low survivability due to this cancer. CRC patients present various genetic changes and epigenetic modifications. The most common genetic alterations associated with CRC are p53 and KRAS mutations. Gene therapy targeting defect genes such as TP53 (tumor suppressor gene encodes for p53) and KRAS (oncogene) in CRC potentially serves as an alternative treatment avenue for the disease in addition to the standard therapy. For the last decade, significant developments have been seen in gene therapy for translational purposes in treating various cancers. This includes the development of vectors as delivery vehicles. Despite the optimism revolving around targeted gene therapy for cancer treatment, it also has various limitations, such as a lack of availability of related technology, high cost of the involved procedures, and ethical issues. This article will provide a review on the potentials and challenges of gene therapy targeting p53 and KRAS for the treatment of CRC.

Impact of Immunoscore on the Management of Stage II Colon Cancer Patients: A Physician Survey

Simple Summary

Selection of appropriate stage II colon cancer patients for adjuvant chemotherapy (AC) is controversial. A novel immune response classifier has previously been validated to refine patient selection, but its impact on oncologist treatment planning had yet to be described. In this survey, all but one oncologist altered clinical practice recommendations, and recommendations for AC prescriptions were reduced by half (among the Immunoscore-high cases (low recurrence risk)). This study revealed that the Immunoscore results could significantly decrease AC use in patients with stage II colon cancer who may not benefit from it, thereby reducing the administration of nonvalue care.

Abstract

Background: Adjuvant chemotherapy use in stage II colon cancer is controversial. Current prognostic risk factors do not take the tumor immune microenvironment into account. Consideration of the Immunoscore, which measures the host immune response at the tumor site, may assist clinicians in reducing adjuvant chemotherapy use in patients who are unlikely to benefit from it. This study sought to determine the potential clinical utility of the Immunoscore, via its effect on medical oncologists’ recommendations for management of patients with stage II colon cancer. Methods: De-identified vignettes of 10 patients with stage II colon cancer were presented to 25 practicing medical oncologists. Each participant completed surveys indicating recommendations for adjuvant chemotherapy and surveillance strategies. An educational session was subsequently conducted, and the same patient profiles were re-presented but included immunoscore results. Participants were again asked to provide their recommendations. A participant was counted as influenced if their responses were altered after immunoscore test results were provided. Results: All but one participant (96%) altered a management recommendation for ≥1 case. For individual cases, a mean of 55% (range, 40–80%) of participants altered their recommendations for adjuvant chemotherapy and/or surveillance. For the immunoscore-high cases (low-risk of recurrence), recommendations for adjuvant chemotherapy use decreased from 60% to 31%. Conclusions: These results indicate a willingness by oncologists to integrate immunoscore information into clinical practice recommendations. Incorporation of immunoscore data resulted in the reduction of nonvalue care in the simulated population. Confirmation in prospective studies is planned.

Cancer-associated fibroblasts impact the clinical outcome and treatment response in colorectal cancer via immune system modulation: a comprehensive genome-wide analysis

Background

Cancer-associated fibroblasts (CAFs) in the tumour microenvironment are associated with poor prognosis and chemoresistance in multiple solid tumours. However, there is a lack of universal measures of CAFs in colorectal cancer (CRC). The aim of this study was to assess the utility of a fibroblast-related gene signature (FRGS) for predicting patient outcomes and reveal its relevant mechanism.

Methods

The GSE39582 dataset, which includes 316 CRC patients who did not receive adjuvant chemotherapy was used as a discovery cohort to identify the prognostic fibroblast-related genes (FRGs). A total of 1352 CRC patients were divided into one training cohort (GSE39582, n = 461) and two validation cohorts (TCGA, n = 338; meta-validation, n = 553) for the construction of the FRGS and the verification of its prognostic value in stage II/III CRC patients. Functional annotation and analysis were performed to explore the underlying mechanism. The ability of the FRGS to predict immunotherapy response was further tested in a clear cell renal cell carcinoma (ccRCC) cohort.

Results

An 11-gene signature that had prognostic value for stage II/III CRC patients in both validation cohorts was developed (TCGA cohort: HR = 1.90, 95% CI 1.16–3.12, P < 0.01; meta-validation cohort: HR = 1.95, 95% CI 1.39–2.73, P < 0.001). A high level of CAFs was correlated with worse prognosis in CRC patients who did not receive adjuvant chemotherapy (HR = 3.63, 95% CI 2.24–5.88, P < 0.001). Importantly, patients in the low-risk group were found to be benefit from chemotherapy (P < 0.01), but not in the high CAF group (P > 0.05). Similar results were found in the TCGA cohort. Integrated with clinical characteristics, the FRGS was confirmed to be an independent prognostic factor in the multivariate analysis after adjustment for tumour TNM stage (GSE39582 cohort: HR = 3.19, 95% CI 1.88–5.41, P < 0.001; TCGA cohort: HR = 5.00, 95% CI 1.58–15.85, P = 0.007; meta-validation cohort: HR = 2.99, 95% CI 1.44–6.21, P = 0.003). Furthermore, the enrichment analysis found that the antitumour immune response was suppressed and the infiltration of CD4 T cells and M1 macrophages was depressed in the high CAF group. The FRGS was also found to have value in predicting for immunotherapy response in the ccRCC cohort.

Conclusions

The 11-gene FRGS had independent prognostic value for CRC patients, as well as utility in the prediction of benefit from chemotherapy. CAFs in the tumour microenvironment might have an impact on the prognosis of CRC patients via inhibiting immune response.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-021-00402-3.

High-Risk Features Are Prognostic in dMMR/MSI-H Stage II Colon Cancer

BACKGROUND

High-risk features, such as T4 disease, bowel obstruction, poorly/undifferentiated histology, lymphovascular, perineural invasion, and <12 lymph nodes sampled, indicate poor prognosis and define high-risk stage II disease in proficient mismatch repair stage II colon cancer (CC). The prognostic role of high-risk features in dMMR/MSI-H stage II CC is unknown. Similarly, the role of adjuvant therapy in high-risk stage II CC with dMMR/MSI-H (≥1 high-risk feature) has not been studied in prospective trials. The aim of this analysis of the National Cancer Database is to evaluate the prognostic value of high-risk features in stage II dMMR/MSI-H CC.

METHODS

Univariate (UVA) and multivariate (MVA) Cox proportional hazards (Cox-PH) models were built to assess the association between clinical and demographic characteristics and overall survival. Kaplan-Meier survival curves were generated with log-rank tests to evaluate the association between adjuvant chemotherapy in high-risk and low-risk cohorts separately.

RESULTS

A total of 2,293 stage II CC patients have dMMR/MSI-H; of those, 29.5% (n = 676) had high-risk features. The high-risk dMMR/MSI-H patients had worse overall survival [5-year survival and 95%CI, 73.2% (67.3-78.1%) vs. 80.3% (76.7-83.5%), p = 0.0001]. In patients with stage II dMMR/MSI-H CC, the high-risk features were associated with shorter overall survival (OS) along with male sex, positive carcinoembryonic antigen, Charlson-Deyo score >1, and older age. Adjuvant chemotherapy administration was associated with better OS, regardless of the high-risk features in dMMR/MSI-H (log-rank test, p = 0.001) or not (p = 0.0006). When stratified by age, the benefit of chemotherapy was evident only in patients age ≥65 with high-risk features.

CONCLUSION

High-risk features are prognostic in the setting of dMMR/MSI-H stage II CC. Adjuvant chemotherapy may improve survival specifically in patients ≥65 years and with high-risk features.

Role of Circulating Tumor DNA in Gastrointestinal Cancers: Current Knowledge and Perspectives

Gastrointestinal (GI) cancers are major health burdens worldwide and biomarkers are needed to improve the management of these diseases along their evolution. Circulating tumor DNA (ctDNA) is a promising non-invasive blood and other bodily-fluid-based biomarker in cancer management that can help clinicians in various cases for the detection, diagnosis, prognosis, monitoring and personalization of treatment in digestive oncology. In addition to the well-studied prognostic role of ctDNA, the main real-world applications appear to be the assessment of minimal residual disease to further guide adjuvant therapy and predict relapse, but also the monitoring of clonal evolution to tailor treatments in metastatic setting. Other challenges such as predicting response to treatment including immune checkpoint inhibitors could also be among the potential applications of ctDNA. Although the level of advancement of ctDNA development in the different tumor localizations is still inhomogeneous, it might be now reliable enough to be soon used in clinical routine for colorectal cancers and shows promising results in other GI cancers.

KRAS and BRAF Mutations in Stage II/III Colon Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

KRAS and BRAF mutations are well-established predictive and prognostic factors in metastatic colorectal cancer, however their impact in the adjuvant setting has not yet been established.

METHODS

We performed a meta-analysis of adjuvant phase III trials in patients with stage II and III colon cancer with available data on the impact of KRAS/BRAF mutations on both disease-free survival (DFS) and overall survival (OS). Trials were subgrouped based on whether adjustment for microsatellite instability (MSI) was performed and the subgroup effect was analyzed through a meta-regression. To increase the precision of the estimates, a joint DFS/OS (so-called 'multivariate') meta-analysis was performed. All statistical tests were 2-sided.

RESULTS

Nine trials were selected (QUASAR 2, PETACC-8, N0147, CALGB-89803, NSABP-C07, NSABP-C08, PETACC-3, QUASAR, MOSAIC) including a total of 10893 patients. In the primary meta-analysis, KRAS mutation was associated with poor DFS (pooled HR = 1.36, 95% CI = 1.15-1.61, P < .001) and OS (pooled HR = 1.27, 95% CI = 1.03-1.55, P = .03) and BRAF mutation was also associated with poor DFS (pooled HR = 1.33, 95% CI = 1.00-1.78, P = .05) and OS (pooled HR = 1.49, 95% CI = 1.31-1.70, P < .001). MSI adjustment enhanced the effect of the mutations on outcome in the MSI-adjusted subgroup for both the KRAS mutation (pooled HR for DFS = 1.43, 95% CI = 1.15-1.79, P = .001; and pooled HR for OS = 1.33, 95% CI = 1.03-1.71, P = .03) and the BRAF mutation (pooled HR for DFS = 1.59, 95% CI = 1.22-2.07, P = .001; and pooled HR for OS = 1.67, 95% CI = 1.37-2.04, P < .001). The interaction between BRAF and MSI adjustment was statistically significant for DFS (P interaction = 0.02). This interaction was even more pronounced in the DFS/OS multivariate meta-analysis.

CONCLUSIONS

Both KRAS and BRAF mutations were statistically significantly associated with both DFS and OS, with the mutation effect being enhanced by MSI adjustment. Effective adjuvant treatment for microsatellite stable BRAF or KRAS-mutated colon cancer represents an unmet clinical need and exploring the use of recently available BRAF and KRAS inhibitors in this setting would be highly desirable.

Chimeric Ad5.F35 vector evades anti-adenovirus serotype 5 neutralization opposing GUCY2C-targeted antitumor immunity

BACKGROUND

Adenovirus serotype 5 (Ad5) is a commonly used viral vector for transient delivery of transgenes, primarily for vaccination against pathogen and tumor antigens. However, endemic infections with Ad5 produce virus-specific neutralizing antibodies (NAbs) that limit transgene delivery and constrain target-directed immunity following exposure to Ad5-based vaccines. Indeed, clinical trials have revealed the limitations that virus-specific NAbs impose on the efficacy of Ad5-based vaccines. In that context, the emerging focus on immunological approaches targeting cancer self-antigens or neoepitopes underscores the unmet therapeutic need for more efficacious vaccine vectors.

METHODS

Here, we evaluated the ability of a chimeric adenoviral vector (Ad5.F35) derived from the capsid of Ad5 and fiber of the rare adenovirus serotype 35 (Ad35) to induce immune responses to the tumor-associated antigen guanylyl cyclase C (GUCY2C).

RESULTS

In the absence of pre-existing immunity to Ad5, GUCY2C-specific T-cell responses and antitumor efficacy induced by Ad5.F35 were comparable to Ad5 in a mouse model of metastatic colorectal cancer. Furthermore, like Ad5, Ad5.F35 vector expressing GUCY2C was safe and produced no toxicity in tissues with, or without, GUCY2C expression. Importantly, this chimeric vector resisted neutralization in Ad5-immunized mice and by sera collected from patients with colorectal cancer naturally exposed to Ad5.

CONCLUSIONS

These data suggest that Ad5.F35-based vaccines targeting GUCY2C, or other tumor or pathogen antigens, may produce clinically relevant immune responses in more (≥90%) patients compared with Ad5-based vaccines (~50%).

The CIRCULATE Trial: Circulating Tumor DNA Based Decision for Adjuvant Treatment in Colon Cancer Stage II Evaluation (AIO-KRK-0217)

BACKGROUND

Guidance regarding adjuvant treatment decisions in stage II colorectal cancer (CRC) remains uncertain due to lack of predictive clinical or molecular markers. Recently, postoperative circulating tumour (ct)DNA has been demonstrated to be a strong prognostic marker in early colon cancer.

PATIENTS AND METHODS

CIRCULATE enrols patients with stage II microsatellite stable CRC in Germany (AIO) and Austria (ABCSG). Within the AIO, screening is supported by ColoPredict Plus 2.0, a molecular registry, and screening platform for interventional trials. Patient-specific mutations are centrally analysed by next generation sequencing in the resected primary tumour. A postoperative plasma sample is subsequently screened for the specific mutation(s). ctDNA positive (ctDNApos) patients are randomised (2:1) chemotherapy (capecitabine, oxaliplatin added an investigator's choice) or to follow-up (control group). ctDNA negative (ctDNAneg) patients are randomised (1:4) to be followed-up within CIRCULATE (control group) or outside the trial. Patients in the control group remain blinded to the ctDNA results. The primary objective is to compare disease free survival (DFS) of ctDNApos patients with chemotherapy or control. To demonstrate a treatment effect with a hazard ratio of 0.617 (3-year DFS rates 42.5% vs. 25%), 231 ctDNApos and estimated 2079 ctDNAneg patients are randomised. Secondary aims include to compare overall survival and DFS in the ctDNApos and ctDNAneg patient cohorts and ctDNA kinetics.

CONCLUSION

The CIRCULATE trial may establish ctDNA for adjuvant treatment decision in stage II colon cancer - and with the secondary objectives - support a ctDNA guided follow up in colon cancer stage II and beyond.

Reevaluating Disease-Free Survival as an Endpoint vs Overall Survival in Stage III Adjuvant Colon Cancer Trials

BACKGROUND

Disease-free survival (DFS) with a 3-year median follow-up (3-year DFS) was validated as a surrogate for overall survival (OS) with a 5-year median follow-up (5-year OS) in adjuvant chemotherapy colon cancer (CC) trials. Recent data show further improvements in OS and survival after recurrence in patients who received adjuvant FOLFOX. Hence, reevaluation of the association between DFS and OS and determination of the optimal follow-up duration of OS to aid its utility in future adjuvant trials are needed.

METHODS

Individual patient data from 9 randomized studies conducted between 1998 and 2009 were included; 3 trials tested biologics. Trial-level surrogacy examining the correlation of treatment effect estimates of 3-year DFS with 5 to 6.5-year OS was evaluated using both linear regression (RWLS2) and Copula bivariate (RCopula2) models and reported with 95% confidence intervals (CIs). For R2, a value closer to 1 indicates a stronger correlation.

RESULTS

Data from a total of 18 396 patients were analyzed (median age = 59 years; 54.0% male), with 54.1% having low-risk tumors (T1-3 and N1), 31.6% KRAS mutated, 12.3% BRAF mutated, and 12.4% microsatellite instability high or deficient mismatch repair tumors. Trial-level correlation between 3-year DFS and 5-year OS remained strong (RWLS2 = 0.82, 95% CI = 0.67 to 0.98; RCopula2 = 0.92, 95% CI = 0.83 to 1.00) and increased as the median follow-up of OS extended. Analyses limited to trials that tested biologics showed consistent results.

CONCLUSIONS

Three-year DFS remains a validated surrogate endpoint for 5-year OS in adjuvant CC trials. The correlation was likely strengthened with 6 years of follow-up for OS.

The Value of Sentinel Lymph Node Mapping for the Staging of Node-Negative Colon Cancer: Propensity Score and Mediation Analyses

Objectives

Mediation analysis to assess the protective impact of sentinel lymph node (SLN) mapping on prognosis and survival of patients with colon cancer through a more precise evaluation of the lymph node (LN) status.

Background

Up to 20% of patients with node-negative colon cancer develop disease recurrence. Conventional histopathological LN examination may be limited in describing the real metastatic burden of LN.

Methods

Data of 312 patients with stage I & II colon cancer was collected prospectively. Patients were either staged using intraoperative SLN mapping with multilevel sectioning and immunohistochemical staining of the SLN or conventional techniques. The value of the SLN mapping for the detection of truly node-negative patients was assessed using Cox regression and mediation analysis.

Results

SLN mapping was performed in 143 patients. Disease recurrence was observed in 13 (9.1%) patients staged with SLN mapping and in 27 (16%) staged conventionally. Five-year overall survival (OS) rate was 82.7% (95% confidence interval [CI], 76.5-89.4%) with SLN mapping compared with 65.8% (95% CI, 58.8-73.7%). Five-year cancer-specific survival (CSS) was 95.1% (95% CI, 91.3-99.0%) with SLN mapping compared with 92.5% (95% CI, 88.0-97.2%). Node-negative staging with SLN mapping was associated with significantly better OS (hazard ratio [HR], 0.64; 95% CI, 0.56-0.72; P < 0.001) and CSS (HR, 0.49; 95% CI, 0.39-0.61; P < 0.001) in multivariate analysis. Mediation analysis confirmed a direct protective effect of SLN mapping on OS (HR, 0.78; 95% CI, 0.52-0.96; P < 0.01) and disease-free survival (DFS) (HR, 0.75; 95% CI, 0.48-0.89; P < 0.01).

Conclusions

Staging performed by SLN mapping with multilevel sectioning provides more accurate results than conventional staging. The observed clinically relevant and statistically significant benefit in OS and DFS is explained by a more accurate detection of positive LN by SLN mapping.

Three Versus Six Months of Adjuvant Doublet Chemotherapy for Patients With Colorectal Cancer: A Multi-Country Cost-Effectiveness and Budget Impact Analysis

BACKGROUND

The Short Course Oncology Treatment (SCOT) trial demonstrated non-inferiority, less toxicity, and cost-effectiveness from a UK perspective of 3 versus 6 months of oxaliplatin-based chemotherapy for patients with colorectal cancer. This study assessed the cost-effectiveness of shorter treatment and the budget impact of implementing trial findings from the perspectives of all countries recruited to SCOT: Australia, Denmark, New Zealand, Spain, Sweden, and the United Kingdom.

PATIENTS AND METHODS

Individual cost-utility analyses were performed from the perspective of each country. Resource, quality of life, and survival estimates from the SCOT trial (N = 6065) were used. Probabilistic sensitivity analysis and subgroup analyses were undertaken. Using undiscounted costs from these cost-utility analyses, the impact on country-specific healthcare budgets of implementing the SCOT trial findings was calculated over a 5-year period. The currency used was US dollars (US$), and 2019 was the base year. One-way and scenario sensitivity analysis addressed uncertainty within the budget impact analysis.

RESULTS

Three months of treatment were cost saving and cost-effective compared to 6 months from the perspective of all countries. The incremental net monetary benefit per patient ranged from US$8972 (Spain) to US$13,884 (Denmark). The healthcare budget impact over 5 years for the base-case scenario ranged from US$3.6 million (New Zealand) to US$61.4 million (UK) and totaled over US$150 million across all countries.

CONCLUSION

This study has widened the transferability of results from the SCOT trial, showing that shorter treatment is cost-effective from a multi-country perspective. The vast savings from implementation could fully justify the investment in conducting the SCOT trial.

[Influence of molecular markers on oncological surgery of colorectal cancer]

Colorectal cancer (CRC) is still a very common disease and one of the best characterized malignancies on a molecular level. Interdisciplinary and multimodal treatment strategies should be preferred. In addition to surgical resection in localized stages as well as metastasectomy for oligometastatic advanced stages, neoadjuvant chemoradiotherapy for localized rectal cancer and cytostatic treatment, targeted treatment approaches should also be considered. This overview presents established and novel prognostic and predictive molecular markers of (metastasized) CRC and describes these as targeted therapy options. The determination of high microsatellite instability (MSI-H) has a therapeutic influence when planning adjuvant therapy and also now in the treatment of metastatic CRC. Furthermore, circulating tumor DNA represents a promising marker with respect to a recurrence in early as well as in advanced stages of disease. In addition to the RAS and BRAF mutation status and the localization of the primary tumor, an MSI‑H is also important with respect to the treatment strategy and should be determined before initiation of first-line treatment in metastasized CRC. New pharmaceutical approaches enable targeted interventions at the immunological or molecular level. The understanding of CRC as a heterogeneous disease has been increased using recently established analyses at the molecular level; however, it also generated many hypotheses that require further evaluation with respect to their clinical importance. Special attention is paid to patients affected by hereditary syndromes because of the early onset of disease and the considerable consequences individually and for the patient's family.

Treatment and Outcomes of Colorectal Cancer in Armenia: A Real-World Experience From a Developing Country

PURPOSE

In Armenia, colorectal cancer (CRC) is one of the most frequently diagnosed cancers. It is in the third place by incidence. The aim of this study was to evaluate treatment and outcomes of CRC in Armenia during the last 9 years.

MATERIALS AND METHODS

For this retrospective hospital-based study, we have collected data from two main oncology centers in Armenia: National Oncology Center and “Muratsan” Hospital of Yerevan State Medical University. The information about patients with CRC who were treated at these two centers between January 1, 2010 and July 1, 2018 was collected from the medical records. Log-rank test and Kaplan-Meier curves were used for survival analysis. Prognostic factors were identified by Cox regression.

RESULTS

A total of 602 patients with CRC were involved in the final analysis. Median follow-up time was 37 months (range, 3-207 months). A total of 8.6% of patients had stage I, 32.9% stage II, 38.0% stage III, and 17.6% stage IV cancer; for 2.7% patients, the stage was unknown. The main independent prognostic factors for overall survival (OS) were tumor stage, grade, and histology. Adjuvant chemotherapy has been shown to improve survival in stage II colon cancer and stage III rectal but not in stage II rectal cancer. Radiotherapy did not yield survival improvement in stage II or III rectal cancer. Three- and 5-year OS rates were 62.9% and 51.8% for all stages combined and 79.7% and 68.5% for stages I-II, 62.5% and 48.4% for stage III, and 24.4% and 17% for stage IV respectively.

CONCLUSION

As seen from our results, our survival rates are lower than those of the developed world. Additional research is needed to identify the underlying reasons and to improve patients’ treatment and outcomes in Armenia.

Detection of Circulating Tumor Cells and Microbial DNA Fragments in Stage III Colorectal Cancer Patients under Three versus Six Months of Adjuvant Treatment

Oxaliplatin-fluoropyrimidine combination therapy is the gold standard treatment for patients with stage III colorectal cancer (CRC); however, treatment duration is now under re-evaluation. The aim of the study was the evaluation of the non-inferiority of three over six months treatment with FOLFOX or CAPOX, in stage III CRC patients. Peripheral blood samples from 121 patients were collected, at three time points during treatment and evaluated for circulating tumor cells (CTCs) and microbial DNA detection (16S rRNA, Escherichia coli, Bacteroides fragilis, Candida albicans). Of all patients, 41.3% and 58.7% were treated with FOLFOX and CAPOX, respectively. CTCs were significantly decreased and increased after three and six months of treatment, respectively. CAPOX tends to reduce the CTCs after 3 months, whereas there is a statistically significant increase of CTCs in patients under FOLFOX after 6 months. A significant correlation was demonstrated between microbial DNA detection and both CTCs detection at baseline and CTCs increase between baseline and three months of treatment. To conclude, the current study provides additional evidence of non-inferiority of three over 6 months of treatment, mainly in patients under CAPOX.

Adjuvant Therapies in Colon Cancer

Most of the patients with localized colon cancer undergo curative resection. However, significant number of patients will recur with metastatic disease, especially those with node positive cancer. Adjuvant chemotherapy has shown to improve cure rate and survival by eradicating micrometastases. The benefit of adjuvant therapy is well established in node-positive cancers, while their role in stage II cancer is not well defined. A number of molecular markers have been identified that are prognostic and/or predictive in colon cancer. Such molecular markers, and other clinicopathological features play an important role in selection of appropriate therapy and duration of treatment. Emerging evidence for the utility of genomic profiling or detection of circulating tumor DNA (ctDNA) are promising which may further facilitate decision making in the future. This chapter reviews the evolution of adjuvant therapy for resected colon cancer, the current evidence and the factors influence the choice of therapy.

The platelet to lymphocyte ratio is a potential inflammatory marker predicting the effects of adjuvant chemotherapy in patients with stage II colorectal cancer

Background

The effects of adjuvant chemotherapy in patients with stage II colorectal cancer (CRC) has been in controversy for a long time. Our study aimed to find an effective inflammatory marker to predict the effects of chemotherapy.

Methods

Seven hundred eight stage II CRC patients in our institution were included. The subpopulation treatment effect pattern plot (STEPP) analysis was used to determine the optimal inflammatory marker and cut-off value. Propensity score matching (PSM) was performed to balance discrepancy between the chemotherapy and non-chemotherapy group. Survival analyses based on overall survival (OS) and cancer-specific survival (CSS) were performed with Kaplan-Meier methods with log-rank test and Cox proportional hazards regression. The restricted mean survival time (RMST) was used to measure treatment effect.

Results

The platelet to lymphocyte ratio (PLR) was chosen as the optimal marker with a cut-off value of 130 according to STEPP. In OS analysis, PLR was significantly associated with the effects of chemotherapy (interaction p = 0.027). In the low-PLR subgroup, the chemotherapy patients did not have a longer OS than the non-chemotherapy patients (HR: 0.983, 95% CI: 0.528–1.829). In the high-PLR subgroup, the chemotherapy patients had a significantly longer OS than the non-chemotherapy patients (HR: 0.371, 95% CI: 0.212–0.649). After PSM, PLR was still associated with the effects of chemotherapy. In CSS analysis, PLR was not significantly associated with the effects of chemotherapy (interaction p = 0.116). In the low-PLR subgroup, the chemotherapy patients did not have a longer CSS than the non-chemotherapy patients (HR: 1.016, 95% CI: 0.494–2.087). In the high-PLR subgroup, the chemotherapy patients had a longer CSS than the non-chemotherapy patients (HR: 0.371, 95% CI: 0.212–0.649). After PSM, PLR was not associated with the effects of chemotherapy.

Conclusions

PLR is an effective marker to predict the effects of chemotherapy in patients with stage II CRC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08521-0.

How I treat stage II colon cancer patients

Stage II colon cancer (CC) is probably one of the best prognosis gastrointestinal tumors seen in our consultations, but often takes a lot of time for physicians to determine appropriate treatment because of the limited benefit of adjuvant chemotherapy (CT) in these patients, together with the limited evidence in this situation. How to choose the best treatment for each individual patient is thus dependent on molecular (microsatellite instability/microsatellite stability status) and clinico-pathological features relevant enough to classify these tumors into low-, intermediate- and high-risk stage II disease and to choose an appropriate attitude for each of these subgroups. In practice, the first step in treatment decision making must be to assess the patient's status and comorbidities to see if the patient is eligible for an adjuvant treatment. Then, as fluoropyrimidines (FPs) are the corner stone of CC adjuvant treatment, screening for dihydropyrimidine dehydrogenase deficiency is mandatory in western countries. Finally, depending on the patient's characteristics and tumor risk stage, the strategy may be surveillance, adjuvant FP alone or oxaliplatin-based adjuvant CT. In the near future, new tools such as Immunoscore® (HalioDx; Luminy Biotech Enterprises, Marseille Cedex, France) and circulating tumor DNA may help to identify more precisely patients with minimal residual disease for more personalized adjuvant treatment approaches.

•

Stage II CC is a heterogeneous disease with a complex management due to the limited data and benefit of adjuvant CT.

•

Risk stratification through prognostic parameters is crucial to aid clinicians in determining the appropriate therapy.

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Lymph node sampling <12 and pT4 are currently recognized as the major prognostic features associated with worse survival.

•

Adjuvant CT should be considered by incorporating prognostic features and balanced against patient's age and comorbidities.

The impact of socioeconomic status on survival in stage III colon cancer patients: A retrospective cohort study using the SEER census-tract dataset

Background

The impact of socioeconomic status (SES) has been described for screening and accessing treatment for colon cancer. However, little is known about the “downstream” effect in patients who receive guideline‐concordant treatment. This study assessed the impact of SES on cancer‐specific survival (CSS) and overall survival (OS) for stage III colon cancer patients.

Methods

The SEER Census Tract‐Level SES Dataset from 2004 to 2015 was used to identify stage III colon adenocarcinoma patients who received curative‐intent surgery and adjuvant chemotherapy. The predictor variable was census tract SES. SES was analyzed as quintiles. The outcome variables were OR and CSS. Statistical analysis included chi square tests for association, Kaplan–Meier, Cox, Fine and Gray regression for survival analysis.

Results

In total, 27,222 patients met inclusion criteria. Lower SES was associated with younger age, Black or Hispanic race/ethnicity, Medicaid/uninsured, higher T stage, and lower grade tumors. CSS at the 25th percentile was 54 months for the lowest SES quintile and 80 for the highest. Median OS was 113 months for the lowest SES quintile and not reached for highest. The 5‐year CSS rate was 72.4% for the lowest SES quintile compared to 78.9% in the highest (p < 0.001). The 5‐year OS rate was 66.5% for the lowest SES quintile and 74.6% in the highest (p < 0.001).

Conclusion

This is the first study to evaluate CSS and OS in an incidence‐based cohort of stage III colon cancer patients using a granular, standardized measure of SES. Despite receipt of guideline‐based treatment, SES was associated with disparities in CSS and OS.

Real-World Effectiveness of Adjuvant Oxaliplatin Chemotherapy in Stage III Colon Cancer: A Controlled Interrupted Time Series Analysis

Background: The real-world effectiveness of oxaliplatin in stage III colon cancer has not been determined in a large-scale population. We aimed to assess the real-world impact of adjuvant oxaliplatin treatment on the survival of these patients.

Methods: Based on Taiwan cancer registry, we evaluated 17,801 patients with resected stage III colon cancer, including 14,168 patients receiving adjuvant chemotherapy and 3,633 not receiving adjuvant chemotherapy as the control group between 2004 and 2014. We used the controlled interrupted time-series analysis to assess the three-year disease-free survival and five-year overall survival rates before (2004–2008) and after (2009–2014) the addition of oxaliplatin.

Results: The introduction of oxaliplatin was associated with no significant improvement in the slopes (per half-year) of the three-year disease-free survival rate (0.2%, 95% CI: −1.7∼2.2%) and five-year overall survival rate (0.6%, 95% CI: −1.8∼3%). The patients receiving oxaliplatin-based chemotherapy also showed no significant increase in the slopes (per half-year) of the three-year disease-free survival rate (0.6%, 95% CI: −1.4∼2.6%) and five-year overall survival rate (1%, 95% CI: −1.5∼3.5%). The nonsignificant results were consistent across subgroup analyses of age (<70 vs. ≥70 years), recurrence risk (T1-3 or N1 vs. T4 or N2), and cycle of oxaliplatin use (≤6 vs. >6). However, oxaliplatin-based chemotherapy significantly increased the slope (per half-year) of the five-year OS (2%, 95% CI: 0.2∼3.8%) for patients in the high-risk group (T4 or N2). The present results were robust in several sensitivity analyses.

Conclusion: Among real-world patients with stage III colon cancer, the introduction of oxaliplatin does not yield a significant improvement in survival. Future work should identify the subpopulation(s) of patients who benefit significantly from the addition of oxaliplatin.

Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines 2020 for the Clinical Practice of Hereditary Colorectal Cancer

Hereditary colorectal cancer (HCRC) accounts for < 5% of all colorectal cancer cases. Some of the unique characteristics commonly encountered in HCRC cases include early age of onset, synchronous/metachronous cancer occurrence, and multiple cancers in other organs. These characteristics necessitate different management approaches, including diagnosis, treatment or surveillance, from sporadic colorectal cancer management. There are two representative HCRC, named familial adenomatous polyposis and Lynch syndrome. Other than these two HCRC syndromes, related disorders have also been reported. Several guidelines for hereditary disorders have already been published worldwide. In Japan, the first guideline for HCRC was prepared by the Japanese Society for Cancer of the Colon and Rectum (JSCCR), published in 2012 and revised in 2016. This revised version of the guideline was immediately translated into English and published in 2017. Since then, several new findings and novel disease concepts related to HCRC have been discovered. The currently diagnosed HCRC rate in daily clinical practice is relatively low; however, this is predicted to increase in the era of cancer genomic medicine, with the advancement of cancer multi-gene panel testing or whole genome testing, among others. Under these circumstances, the JSCCR guidelines 2020 for HCRC were prepared by consensus among members of the JSCCR HCRC Guideline Committee, based on a careful review of the evidence retrieved from literature searches, and considering the medical health insurance system and actual clinical practice settings in Japan. Herein, we present the English version of the JSCCR guidelines 2020 for HCRC.

Analyzing the Opportunities to Target DNA Double-Strand Breaks Repair and Replicative Stress Responses to Improve Therapeutic Index of Colorectal Cancer

Despite the ample improvements of CRC molecular landscape, the therapeutic options still rely on conventional chemotherapy-based regimens for early disease, and few targeted agents are recommended for clinical use in the metastatic setting. Moreover, the impact of cytotoxic, targeted agents, and immunotherapy combinations in the metastatic scenario is not fully satisfactory, especially the outcomes for patients who develop resistance to these treatments need to be improved. Here, we examine the opportunity to consider therapeutic agents targeting DNA repair and DNA replication stress response as strategies to exploit genetic or functional defects in the DNA damage response (DDR) pathways through synthetic lethal mechanisms, still not explored in CRC. These include the multiple actors involved in the repair of DNA double-strand breaks (DSBs) through homologous recombination (HR), classical non-homologous end joining (NHEJ), and microhomology-mediated end-joining (MMEJ), inhibitors of the base excision repair (BER) protein poly (ADP-ribose) polymerase (PARP), as well as inhibitors of the DNA damage kinases ataxia-telangiectasia and Rad3 related (ATR), CHK1, WEE1, and ataxia-telangiectasia mutated (ATM). We also review the biomarkers that guide the use of these agents, and current clinical trials with targeted DDR therapies.

Microsatellite Instability as a Predictor of Outcomes in Colorectal Cancer in the Era of Immune-Checkpoint Inhibitors

The microsatellite instable phenotype resulting from errors in DNA mismatch repair proteins accounts for as far as 15 to 20% of non-hereditary colon cancers but is scarce in rectal cancer. It has been shown that the increased existence of tumor-specific neoantigens in hypermutated tumors is correlated with higher tumor-infiltrating lymphocytes (TILs) and overexpression of immune checkpoint receptors and ligands, mainly PD-1 and PD-L1. In particular, the data gained up to now gives evidence that neoantigen recognition constitutes a dominant component in the course of immunotherapies. This review's primary objective is to describe current approvals and summarize present knowledge about the outcomes of immuno-oncology treatment of microsatellite instable colorectal cancer (CRC). The secondary objective is to give a narrative report about testing methodologies, prognostics, and the predictive value of microsatellite instability. For this purpose, a literature review was performed, focusing on published clinical trial results, ongoing clinical trials and timelines, testing methods, and prognostic and predictive value of MSI. Following four recent FDA approvals of immunotherapy of MSI-high CRC, further work should be warranted by pathology societies towards standardization and rising concordance and reproducibility across the IHC/MSI testing landscape in order to facilitate professionals to offer better survival options for patients with CRC.

Circulating Tumor DNA Analyses as Markers of Recurrence Risk and Benefit of Adjuvant Therapy for Stage III Colon Cancer

Importance

Adjuvant chemotherapy in patients with stage III colon cancer prevents recurrence by eradicating minimal residual disease. However, which patients remain at high risk of recurrence after completing standard adjuvant treatment cannot currently be determined. Postsurgical circulating tumor DNA (ctDNA) analysis can detect minimal residual disease and is associated with recurrence in colorectal cancers.

Objective

To determine whether serial postsurgical and postchemotherapy ctDNA analysis could provide a real-time indication of adjuvant therapy efficacy in stage III colon cancer.

Design, Setting, and Participants

This multicenter, Australian, population-based cohort biomarker study recruited 100 consecutive patients with newly diagnosed stage III colon cancer planned for 24 weeks of adjuvant chemotherapy from November 1, 2014, through May 31, 2017. Patients with another malignant neoplasm diagnosed within the last 3 years were excluded. Median duration of follow-up was 28.9 months (range, 11.6-46.4 months). Physicians were blinded to ctDNA results. Data were analyzed from December 10, 2018, through June 23, 2019.

Exposures

Serial plasma samples were collected after surgery and after chemotherapy. Somatic mutations in individual patients' tumors were identified via massively parallel sequencing of 15 genes commonly mutated in colorectal cancer. Personalized assays were designed to quantify ctDNA.

Main Outcomes and Measures

Detection of ctDNA and recurrence-free interval (RFI).

Results

After 4 exclusions, 96 eligible patients were eligible; median patient age was 64 years (range, 26-82 years); 49 (51%) were men. At least 1 somatic mutation was identified in the tumor tissue of all 96 evaluable patients. Circulating tumor DNA was detectable in 20 of 96 (21%) postsurgical samples and was associated with inferior recurrence-free survival (hazard ratio [HR], 3.8; 95% CI, 2.4-21.0; P < .001). Circulating tumor DNA was detectable in 15 of 88 (17%) postchemotherapy samples. The estimated 3-year RFI was 30% when ctDNA was detectable after chemotherapy and 77% when ctDNA was undetectable (HR, 6.8; 95% CI, 11.0-157.0; P < .001). Postsurgical ctDNA status remained independently associated with RFI after adjusting for known clinicopathologic risk factors (HR, 7.5; 95% CI, 3.5-16.1; P < .001).

Conclusions and Relevance

Results suggest that ctDNA analysis after surgery is a promising prognostic marker in stage III colon cancer. Postchemotherapy ctDNA analysis may define a patient subset that remains at high risk of recurrence despite completing standard adjuvant treatment. This high-risk population presents a unique opportunity to explore additional therapeutic approaches.

Development and external validation of a novel nomogram for screening Chinese Lynch syndrome: based on a multicenter, population study

Background

This multicenter study aimed to reveal the genetic spectrum of colorectal cancer (CRC) with deficient mismatch repair (dMMR) and build a screening model for Lynch syndrome (LS).

Methods

Through the immunohistochemical (IHC) screening of mismatch repair protein results in postoperative CRC patients, 311 dMMR cases, whose germline and somatic variants were detected using the ColonCore panel, were collected. Univariate and multivariate logistic regression analysis was performed on the clinical characteristics of these dMMR individuals, and a clinical nomogram, incorporating statistically significant factors identified using multivariate logistic regression analysis, was constructed to predict the probability of LS. The model was validated externally by an independent cohort.

Results

In total, 311 CRC patients with IHC dMMR included 95 identified MMR germline variant (LS) cases and 216 cases without pathogenic or likely pathogenic variants in MMR genes (non-Lynch-associated dMMR). Of the 95 individuals, approximately 51.6%, 28.4%, 14.7%, and 5.3% cases carried germline MLH1, MSH2, MSH6, and PMS2 pathogenic or likely pathogenic variants, respectively. A novel nomogram was then built to predict the probability of LS for CRC patients with dMMR intuitively. The receiver operating characteristic (ROC) curve informed that this nomogram-based screening model could identify LS with a higher specificity and sensitivity with an area under curve (AUC) of 0.87 than current screening criteria based on family history. In the external validation cohort, the AUC of the ROC curve reached 0.804, inferring the screening model's universal applicability. We recommend that dMMR-CRC patients with a probability of LS greater than 0.435 should receive a further germline sequencing.

Conclusion

This novel screening model based on the clinical characteristic differences between LS and non-Lynch-associated dMMR may assist clinicians to preliminarily screen LS and refer susceptible patients to experienced specialists.

Rhodium Complexes Targeting DNA Mismatches as a Basis for New Therapeutics in Cancers Deficient in Mismatch Repair

Cancers with microsatellite instability (MSI), which include ≤20% of solid tumors, are characterized by resistance to chemotherapy due to deficiency in the DNA mismatch repair (MMR) pathway. Rhodium metalloinsertors make up a class of compounds that bind DNA mismatches with high specificity and show selective cytotoxicity in MSI cancer cells. We determined that rhodium complexes with an N∧O coordination showed significantly increased cell potency compared with that of N∧N-coordinated compounds, and we identified [Rh(chrysi)(phen)(PPO)]²⁺ (RhPPO) as the most potent, selective compound in this class. Using matched cell lines that are MMR-deficient (HCT116O) and MMR-proficient (HCT116N), we demonstrated that RhPPO preferentially activates the DNA damage response and inhibits DNA replication and cell proliferation in HCT116O cells, leading to cell death by necrosis. Using a fluorescent conjugate of RhPPO, we established that the metalloinsertor localizes to DNA mismatches in the cell nucleus and causes DNA double-strand breaks at or near the mismatch sites. Evaluation of RhPPO across MMR-deficient and MMR-proficient cell lines confirmed the broad potential for RhPPO to target MSI cancers, with cell potency significantly higher than that of platinum complexes used broadly as chemotherapeutics. Moreover, in a mouse xenograft model of MSI cancer, RhPPO shows promising antitumor activity and increased survival. Thus, our studies indicate that RhPPO is a novel DNA-targeted therapy with improved potency and selectivity over standard-of-care platinum-based chemotherapy and, importantly, that DNA mismatches offer a critical new target in the design of chemotherapeutics for MSI cancers.

Colorectal cancer with microsatellite instability: Right-sided location and signet ring cell histology are associated with nodal metastases, and extranodal extension influences disease-free survival

Colorectal cancer (CRC) with microsatellite instability (MSI) accounts for 15-18 % of all CRCs and represents the category with the best prognosis. This study aimed at determining any possible clinical/pathological features associated with a higher risk of nodal metastasization in MSI-CRC, and at defining any possible prognostic moderators in this setting. All surgically resected CRCs of the last 20 years (mono-institutional series) with a PCR-based diagnosis of MSI, with and without nodal metastasis, have been retrieved for histological review, which was performed following WHO guidelines. Furthermore, the most important prognostic moderators have been investigated with a survival analysis. The study of 33 cases of MSI-CRCs with nodal metastasis highlighted a high fidelity of histology maintenance between primary tumors and matched nodal metastases. At survival analysis, the strongest prognostic variable in MSI-CRCs with nodal metastasis was the extranodal extension (multivariate analysis, HR: 14.4, 95 %CI: 1.46-140.9, p = 0.022). Furthermore, through a comparison between nodal positive (33 cases) and nodal negative (71 cases) MSI-CRCs, right-sided location (p < 0.0001), pT4 stage (p = 0.0004) and signet-ring histology (p = 0.0089) emerged as parameters more commonly associated with nodal metastasization. These findings shed new light on the biology of MSI-CRC and can be of help for the prognostic stratification of MSI-CRC patients.

Prognostic value and relation with adjuvant treatment duration of ctDNA in stage III colon cancer: a post-hoc analysis of the PRODIGE-GERCOR IDEA-France trial

PURPOSE

Circulating tumor DNA (ctDNA) has been suggested as a major prognostic factor in resected stage III colon cancer. We analyzed ctDNA of patients randomized in the phase III IDEA-France trial.

EXPERIMENTAL DESIGN

ctDNA was tested for WIF1 and NPY by droplet digital PCR with method developed and validated for colorectal cancer. Disease-free survival (DFS) and overall survival (OS) were analyzed via multivariable analysis in patients with ctDNA samples and in sub-groups according to treatment duration (3/6 months) and disease stage (high/low-risk stage III).

RESULTS

Of 2010 randomized patients, 1345 had available ctDNA samples (1017 collected both post-surgery and pre-chemotherapy). More ECOG PS of 0 (78% versus 69%) and T4 and/or N2 (40% versus 36%) were observed in patients studied (n=1017) versus not analyzed (n=993). There were 877 ctDNA-negative (86.2%) and 140 ctDNA-positive (13.8%) patients; their baseline characteristics were similar. With a median follow-up of 6.6 years, the 3-year DFS rate was 66.39% for ctDNA-positive patients and 76.71% for ctDNA-negative patients (P=0.015). ctDNA was confirmed as an independent prognostic marker for DFS (adjusted HR=1.55, 95% CI 1.13-2.12, P=0.006) and OS (HR=1.65, 95% CI 1.12-2.43, P=0.011). ctDNA was prognostic in patients treated for 3 months and with T4 and/or N2 tumors, but not in those treated for 6 months and with T1-3/N1 tumors.

CONCLUSIONS

In this first ctDNA assessment of a large series of stage III colon cancer patients enrolled in phase III trial, post-surgery ctDNA was found in 13.8% of them and was confirmed as an independent prognostic marker.

Relationship between microsatellite status and immune microenvironment of colorectal cancer and its application to diagnosis and treatment

Due to advances in understanding the immune microenvironment of colorectal cancer (CRC), microsatellite classification (dMMR/MSI-H and pMMR/MSS) has become a key biomarker for the diagnosis and treatment of CRC patients and therefore has important clinical value. Microsatellite status is associated with a variety of clinicopathological features and affects drug resistance and the prognosis of patients. CRC patients with different microsatellite statuses have different compositions and distributions of immune cells and cytokines within their tumor microenvironments (TMEs). Therefore, there is great interest in reversing or reshaping CRC TMEs to transform immune tolerant "cold" tumors into immune sensitive "hot" tumors. This requires a thorough understanding of differences in the immune microenvironments of MSI-H and MSS type tumors. This review focuses on the relationship between CRC microsatellite status and the immune microenvironment. It focuses on how this relationship has value for clinical application in diagnosis and treatment, as well as exploring the limitations of its current application.

A pilot study of a low glycemic load diet in patients with stage I-III colorectal cancer

Background

Consumption of a diet with high glycemic indices has been associated with inferior cancer-specific outcomes in patients with early-stage colorectal cancer, but there is limited prospective evidence that alterations in dietary habits improves cancer outcomes. This study aimed to determine the feasibility and acceptability of following a low glycemic load (GL) diet in patients with stage I-III colorectal cancer.

Methods

Patients with stage I-III colorectal cancer, who completed definitive therapy, and consumed an average daily GL >150 participated in a 12-week tailored face-to-face dietary intervention with a target GL. This study followed a 2-stage design, with 4 planned cohorts, each with an assigned GL target and dietary intervention intensity. The primary endpoint of feasibility was determined by participant compliance, defined as an individual following the assigned GL ≥75% of the time. Compliance was determined using 24-hour telephone recalls. A cohort was deemed feasible if at least 67% of participants were compliant. Secondary endpoints included acceptability of the diet, nutritional support resources necessary to follow the diet, and evaluation of the effect of the diet on physical measures and correlative laboratories.

Results

Only cohort 1 was required as the primary endpoint of feasibility was met (stringent GL target, low intensity dietary support). The majority of participants experienced a decrease in body mass index (BMI) and waist circumference, 29% experiencing meaningful weight loss (≥5%). The dietitian spent an average of 6.97 hours (SD 2.18) face-to-face time and 1.58 hours (SD 0.68) by phone with each participant. Significant decreases were seen in total cholesterol, very-low-density lipoprotein (VLDL) and triglycerides (all P<0.05). All participants liked the foods and were satisfied with the diet. All participants felt the in-person meetings were helpful, and 62% did not feel a virtual meeting (e.g., Skype, etc.) could replace in-person meetings.

Conclusions

Patients with stage I-III colorectal cancer can follow a low GL diet with a 12-week in-person dietary intervention. Significant changes in physical and laboratory measures suggest relevant biologic effects of the dietary intervention. This study establishes feasibility, and warrants a larger scale prospective intervention trial to evaluate the impact of a low GL diet on cancer outcomes.

Accurate Prediction of Prognosis by Integrating Clinical and Molecular Characteristics in Colon Cancer

Various factors affect the prognosis of patients with colon cancer. Complicated factors are found to be conducive to accurate assessment of prognosis. In this study, we developed a series of prognostic prediction models for survival time of colon cancer patients after surgery. Analysis of nine clinical characteristics showed that the most important factor was the positive lymph node ratio (LNR). High LNR was the most important clinical factor affecting 1- and 3-year survival; M0&age < 70 was the most important feature for 5 years. The performance of the model was improved through the integration of clinical characteristics and four types of molecule features (mRNA, lncRNA, miRNA, DNA methylation). The model provides guidance for clinical practice. According to the high-risk molecular features combined with age ≥ 70&T3, poorly differentiated or undifferentiated, M0&well differentiated, M0&T2, LNR high, T4&poorly differentiated, or undifferentiated, the survival time may be less than 1 year; for patients with high risk of molecular features combined with M0&T2, M0&T4, LNR 0& M0, LNR median &T3, and LNR high, the survival is predicted less than 3 years; and the survival of patients with M1&T3, M0 and high risk molecular features is less than 5 years. Using multidimensional and complex patient information, this study establishes potential criteria for clinicians to evaluate the survival of patients for colon cancer.

Cancer-Associated Fibroblasts and Tumor-Associated Macrophages in Cancer and Cancer Immunotherapy

Our understanding of the tumor microenvironment (TME), including the interplay between tumor cells, stromal cells, immune cells, and extracellular matrix components, is mandatory for the innovation of new therapeutic approaches in cancer. The cell-cell communication within the TME plays a pivotal role in the evolution and progression of cancer. Cancer-associated fibroblasts (CAF) and tumor-associated macrophages (TAM) are major cell populations in the stroma of all solid tumors and often exert protumorigenic functions; however, the origin and precise functions of CAF and TAM are still incompletely understood. CAF and TAM hold significant potential as therapeutic targets to improve outcomes in oncology when combined with existing therapies. The regulation of CAF/TAM communication and/or their differentiation could be of high impact for improving the future targeted treatment strategies. Nevertheless, there is much scope for research and innovation in this field with regards to the development of novel drugs. In this review, we elaborate on the current knowledge on CAF and TAM in cancer and cancer immunotherapy. Additionally, by focusing on their heterogenous functions in different stages and types of cancer, we explore their role as potential therapeutic targets and highlight certain aspects of their functions that need further research.

Risk factors of mFOLFOX6-induced hyperammonemia in patients with colorectal cancer: an observational study

BACKGROUND

FOLFOX therapy, a standard treatment for colorectal cancer (CRC), causes a rare, but serious adverse event, hyperammonemia. However, the risk factors of hyperammonemia remain unknown.

METHODS

We examined 74 patients who received mFOLFOX6 therapy with or without biologics for CRC between April 2013 and March 2018 in Yaizu City Hospital. Clinicopathological factors were retrospectively reviewed in association with hyperammonemia, and risk factors of hyperammonemia during mFOLFOX6 therapy were analyzed in 32 patients with the available data.

RESULTS

Seven patients developed hyperammonemia, with onset exclusively on day 2 or 3 in the first cycle of therapy. They were treated with branched chain amino acid administration and hydration; however, one patient with stage G4 chronic kidney disease (CKD) died. By multivariate analysis, estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m² was independently associated with hyperammonemia during FOLFOX therapy (odds ratio: 9.0, p = 0.040).

CONCLUSIONS

Reduced eGFR is considered a risk factor of developing hyperammonemia during FOLFOX therapy. Serum ammonia levels should be monitored especially during the first cycle of FOLFOX therapy in patients with CKD stage G3 or higher.

HNF1A regulates colorectal cancer progression and drug resistance as a downstream of POU5F1

POU5F1-expressing cells can self-renew and differentiate, contributing to metastasis formation in colorectal cancer (CRC), but it plays an important role in normal pluripotent stem cells. Here, we identified the CRC-specific gene, HNF1A, which is the downstream of POU5F1. HNF1A associates with fatty acid and glucose metabolism, and CRC cells highly expressed it. In 198 CRC patients, high HNF1A expression was an independent predictor of disease-free (P = 0.031) and overall (P = 0.007) survival. HNF1A-knockdown showed significantly reduced cell growth, increased apoptosis, and improved anticancer drug sensitivity. We revealed that HNF1A regulated controlled GLUT1 expression via HIF1A and multidrug resistance protein function to suppress SRI. HNF1A expression was elevated in persister cells after exposure to anticancer drugs, and anticancer drug sensitivity was also improved in persister cells via the inhibition of HNF1A. In conclusion, HNF1A expression can reflect resistance to anticancer drug treatment, and its suppression improves anticancer drug sensitivity as a new therapeutic target.

Therapeutic implications of B-RAF mutations in colorectal cancer

Colorectal cancers (CRC) with B-RAF mutation carry a particularly poor prognosis. In this context, the value of first-line intensified chemotherapy associated with an anti-VEGF (Vascular endothelial growth factor) to treat metastatic CRC has recently been called into question. In patients with mutated B-RAF, the efficacy of first-line anti-EGFR (Epidermal Growth Factor Receptor) associated with chemotherapy for treatment of metastatic CRC is uncertain while that of anti-VEGF has been shown to be effective. The therapeutic pathways involving inhibition of B-RAF activity, although ineffective as monotherapy, have received marketing authorization when used in association with anti-EGFR for second-line treatment of metastatic CRC. Immunotherapy has provided very encouraging results in a recent phase III study in patients with microsatellite instability, irrespective of their B-RAF status. Finally, new therapies, targeting other RAF proteins and other specific receptors are currently under development. Surgery for liver metastases in patients with the B-RAF mutation should be considered whenever possible, after a complete search for peritoneal carcinomatosis and distant metastases, similarly to workup for patients without the B-RAF mutation.

High expression of microRNA-126 relates to favorable prognosis for colon cancer patients

miR-126 has been identified both as a tumor suppressor and an oncogene in different types of cancer. The aim of this study was to investigate the prognostic impact of miR-126-expression in colon cancer patients. Tumor tissue from 452 patients operated for stage I–III colon cancer was retrospectively collected and tissue microarrays were constructed. miR-126 expression was evaluated by in situ hybridization and analyzed using digital pathology. To isolate the compartment specific contribution of miR-126, tumor and adjacent tumor stroma were considered separately. In univariate analyses, high expression of miR-126 in tumor and stroma was related to increased disease-specific survival (p < 0.001 and p = 0.005, respectively). In multivariate analyses, high miR-126 expression in tumor remained a significant independent predictor of improved disease-specific survival (HR = 0.42, CI 0.23–0.75, p = 0.004). Within different TNM-stages there was a tendency towards the same results, but with statistically significant results in stage II only (p = 0.007). High expression of miR-126 is an independent positive prognostic factor in stage I–III colon cancer. This finding may be used to identify patients in need of adjuvant chemotherapy.

Hospital-level compliance with the commission on cancer's quality of care measures and the association with patient survival

Background

Quality measurement has become a priority for national healthcare reform, and valid measures are necessary to discriminate hospital performance and support value‐based healthcare delivery. The Commission on Cancer (CoC) is the largest cancer‐specific accreditor of hospital quality in the United States and has implemented Quality of Care Measures to evaluate cancer care delivery. However, none has been formally tested as a valid metric for assessing hospital performance based on actual patient outcomes.

Methods

Eligibility and compliance with the Quality of Care Measures are reported within the National Cancer Database, which also captures data for robust patient‐level risk adjustment. Hospital‐level compliance was calculated for the core measures, and the association with patient survival was tested using Cox regression.

Results

Seven hundred sixty‐eight thousand nine hundred sixty‐nine unique cancer cases were included from 1323 facilities. Increasing hospital‐level compliance was associated with improved survival for only two measures, including a 35% reduced risk of mortality for the gastric cancer measure G15RLN (HR 0.65, 95% CI 0.58–0.72) and a 19% reduced risk of mortality for the colon cancer measure 12RLN (HR 0.81, 95% CI 0.77–0.85). For the lung cancer measure LNoSurg, increasing compliance was paradoxically associated with an increased risk of mortality (HR 1.14, 95% CI 1.08–1.20). For the remaining measures, hospital‐level compliance demonstrated no consistent association with patient survival.

Conclusion

Hospital‐level compliance with the CoC’s Quality of Care Measures is not uniformly aligned with patient survival. In their current form, these measures do not reliably discriminate hospital performance and are limited as a tool for value‐based healthcare delivery.

ZNF37A promotes tumor metastasis through transcriptional control of THSD4/TGF-β axis in colorectal cancer

Poorly differentiated colorectal cancer (CRC) is characterized by aggressive invasion and stromal fibroblast activation, which results in rapid progression and poor therapeutic consequences. However, the regulatory mechanism involved remains unclear. Here, we showed that ZNF37A, a member of KRAB-ZFP family, was upregulated in poorly differentiated CRCs and associated with tumor metastasis. ZNF37A enhanced the metastatic potential of multiple CRC cell lines and promoted distant metastasis in an orthotopic CRC model. Further investigation attributed the ZNF37A-exacerbated metastasis to increased extracellular TGF-β and the consequent activation of cancer-associated fibroblasts (CAFs) in tumor microenvironment (TME). Mechanistically, ZNF37A formed a complex with KAP1 and bound to the promoter of THSD4, a TME modulator, to suppress its transcription, which is required for ZNF37A-mediated TGF-β activation and CRC metastasis. Collectively, our study indicates that ZNF37A promotes TGF-β signaling in CRC cells and activates CAFs by transcriptionally repressing THSD4 to drive CRC metastasis, implicating ZNF37A as a potential biomarker for CRC differentiation and progression.