A randomized trial of intensive versus minimal surveillance of patients with resected Dukes B2-C colorectal carcinoma

Cost-effectiveness of surveillance intervals after curative resection of colorectal cancer

BACKGROUND

Major guidelines consistently recommend 5 years of postoperative surveillance for patients with colorectal cancer. However, they differ in their recommendations for examination intervals and whether they should vary according to disease stage. Furthermore, there are no reports on the cost-effectiveness of the different surveillance schedules. The objective of this study is to identify the most cost-effective surveillance intervals after curative resection of colorectal cancer.

METHODS

A total of 3701 patients who underwent curative surgery for colorectal cancer at the National Cancer Center Hospital were included. A cost-effectiveness analysis was conducted for the five surveillance strategies with reference to the guidelines. Expected medical costs and quality-adjusted life years after colorectal cancer resection were calculated using a state-transition model by Monte Carlo simulation. The incremental cost-effectiveness ratio per quality-adjusted life years gained was calculated for each strategy, with a maximum acceptable value of 43 500-52 200 USD (5-6 million JPY).

RESULTS

Stages I, II and III included 1316, 1082 and 1303 patients, respectively, with 45, 140 and 338 relapsed cases. For patients with stage I disease, strategy 4 (incremental cost-effectiveness ratio $26 555/quality-adjusted life year) was considered to be the most cost-effective, while strategies 3 ($83 071/quality-adjusted life year) and 2 ($289 642/quality-adjusted life year) exceeded the threshold value. In stages II and III, the incremental cost-effectiveness ratio for strategy 3 was the most cost-effective option, with an incremental cost-effectiveness ratio of $18 358-22 230/quality-adjusted life year.

CONCLUSIONS

In stage I, the cost-effectiveness of intensive surveillance is very poor and strategy 4 is the most cost-effective. Strategy 3 is the most cost-effective in stages II and III.

Non-metastatic colon cancer: French Intergroup Clinical Practice Guidelines for diagnosis, treatments, and follow-up (TNCD, SNFGE, FFCD, GERCOR, UNICANCER, SFCD, SFED, SFRO, ACHBT, SFP, AFEF, and SFR)

INTRODUCTION

This article is a summary of the French intergroup guidelines regarding the management of non-metastatic colon cancer (CC), revised in November 2022.

METHODS

These guidelines represent collaborative work of all French medical and surgical societies involved in the management of CC. Recommendations were graded in three categories (A, B, and C) according to the level of evidence found in the literature published up to November 2022.

RESULTS

Initial evaluation of CC is based on clinical examination, colonoscopy, chest-abdomen-pelvis computed tomography (CT) scan, and carcinoembryonic antigen (CEA) assay. CC is usually managed by surgery and adjuvant treatment depending on the pathological findings. The use of adjuvant therapy remains a challenging question in stage II disease. For high-risk stage II CC, adjuvant chemotherapy must be discussed and fluoropyrimidine monotherapy or oxaliplatin-based chemotherapy proposed according to the type and number of poor prognostic features. Oxaliplatin-based chemotherapy (FOLFOX or CAPOX) is the current standard for adjuvant therapy of patients with stage III CC. However, these regimens are associated with significant oxaliplatin-induced neurotoxicity. The results of the recent IDEA study provide evidence that 3 months of treatment with CAPOX is as effective as 6 months of oxaliplatin-based therapy in patients with low-risk stage III CC (T1-3 and N1). A 6-month oxaliplatin-based therapy remains the standard of care for high-risk stage III CC (T4 and/or N2). For patients unfit for oxaliplatin, fluoropyrimidine monotherapy is recommended.

CONCLUSION

French guidelines for non-metastatic CC management help to offer the best personalized therapeutic strategy in daily clinical practice. Each individual case must be discussed within a multidisciplinary tumor board and then the treatment option decided with the patient.

Quality of Surgical Outcome Reporting in Randomised Clinical Trials of Multimodal Rectal Cancer Treatment: A Systematic Review

INTRODUCTION

Randomised controlled trials (RCTs) continue to provide the best evidence for treatment options, but the quality of reporting in RCTs and the completeness rate of reporting of surgical outcomes and complication data vary widely. The aim of this study was to measure the quality of reporting of the surgical outcome and complication data in RCTs of rectal cancer treatment and whether this quality has changed over time.

METHODS

Eligible articles with the keywords ("rectal cancer" OR "rectal carcinoma") AND ("radiation" OR "radiotherapy") that were RCTs and published in the English, German, Polish, or Italian language were identified by reviewing all abstracts published from 1982 through 2022. Two authors independently screened and analysed all studies. The quality of the surgical outcome and complication data was assessed based on fourteen criteria, and the quality of RCTs was evaluated based on a modified Jadad scale. The primary outcome was the quality of reporting in RCTs and the completeness rate of reporting of surgical results and complication data.

RESULTS

A total of 340 articles reporting multimodal therapy outcomes for 143,576 rectal cancer patients were analysed. A total of 7 articles (2%) met all 14 reporting criteria, 13 met 13 criteria, 27 met from 11 to 12 criteria, 36 met from 9 to 10 criteria, 76 met from 7 to 8 criteria, and most articles met fewer than 7 criteria (mean 5.5 criteria). Commonly underreported criteria included complication severity (15% of articles), macroscopic integrity of mesorectal excision (17% of articles), length of stay (18% of articles), number of lymph nodes (21% of articles), distance between the tumour and circumferential resection margin (CRM) (26% of articles), surgical radicality according to the site of the primary tumour (R0 vs. R1 + R2) (29% of articles), and CRM status (38% of articles).

CONCLUSION

Inconsistent surgical outcome and complication data reporting in multimodal rectal cancer treatment RCTs is standard. Standardised reporting of clinical and oncological outcomes should be established to facilitate comparing studies and results of related research topics.

Intensive follow-up vs conventional follow-up for patients with non-metastatic colorectal cancer treated with curative intent: A meta-analysis

BACKGROUND

The frequency and content of follow-up strategies remain controversial for colorectal cancer (CRC), and scheduled follow-ups have limited value.

AIM

To compare intensive and conventional follow-up strategies for the prognosis of non-metastatic CRC treated with curative intent using a meta-analysis.

METHODS

PubMed, Embase, and the Cochrane Library databases were systematically searched for potentially eligible randomized controlled trials (RCTs) from inception until April 2023. The Cochrane risk of bias was used to assess the methodological quality of the included studies. The hazard ratio, relative risk, and 95% confidence interval were used to calculate survival and categorical data, and pooled analyses were performed using the random-effects model. Additional exploratory analyses were performed for sensitivity, subgroups, and publication bias.

RESULTS

Eighteen RCTs involving 8533 patients with CRC were selected for the final analysis. Intensive follow-up may be superior to conventional follow-up in improving overall survival, but this difference was not statistically significant. Moreover, intensive follow-up was associated with an increased incidence of salvage surgery compared to conventional follow-up. In addition, there was no significant difference in the risk of recurrence between intensive and conventional follow-up strategies, whereas intensive follow-up was associated with a reduced risk of interval recurrence compared to conventional follow-up. Finally, the effects of intensive and conventional follow-up strategies differed when stratified by tumor location and follow-up duration.

CONCLUSION

Intensive follow-up may have a beneficial effect on the overall survival of patients with non-metastatic CRC treated with curative intent.

Survivorship in Early-Stage Rectal Cancer Patients Who Have Received Combined Modality Therapy

Survival rates in early-stage rectal cancer patients have increased over the past few decades. Societies such as the National Comprehensive Cancer Network (NCCN), American Cancer Society (ACS), American Society of Clinical Oncology (ASCO), and European Society of Medical Oncology (ESMO) have proposed guidelines related to cancer survivorship care including formal recommendations to address the needs in early-stage rectal cancer survivors. These guidelines, in addition to new clinical research findings in survivorship will be reviewed, specifically looking at physical, psychosocial, and financial concerns in rectal cancer survivorship.

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).

Effect of High-Versus Low-Frequency of Abdominopelvic Computed Tomography Follow-Up Testing on Overall Survival in Patients With Stage II Or III Colon Cancer

BACKGROUND

Intensive surveillance of colon cancer by using the abdominopelvic computed tomography (AP-CT) is common in real world practice; however, it is still unclear whether high-frequency surveillance using AP-CT in patients with these risk factors is superior to that in the low-frequency surveillance.

PATIENTS AND METHODS

We retrospectively reviewed 1803 patients with stage II-III colon cancer receiving curative surgery between January 1, 2005 to December 31, 2015. We evaluated the average scan-to-scan intervals of postoperative AP-CT testing and assigned patients with an interval of 5 to 8 and 9 to 13 months to the high-frequency (HF) and low-frequency (LF) groups, respectively. The cutoff value of preoperative and postoperative CEA levels was 5 ng/mL. We also applied propensity score matching (PSM) and inverse probability of treatment weighting to adjust clinicopathologic differences between the 2 groups.

RESULTS

We matched 1:1 for each surveillance group yielding a cohort of 776 matched patients. After PSM, Baseline demographics were overall well balanced between 2 groups. Stage III (OR, 2.00; 95% Confidence interval [CI], 1.21-3.30) and postoperative CEA elevation (OR, 2.30; 95% CI, 1.08-4.92) were independent risk factors of recurrence in multivariate analyses. Patient in the HF group had more surgery plus chemo- or radiotherapy as postrecurrence treatment than patient in the LF group (46.2% vs. 23.1%, P = .017). This trend was retained after PSM, although it is not significant (44.4% vs. 23.1%, P = .060). However, survival outcomes of high-frequency AP-CT surveillance were not superior to those of low-frequency surveillance in all subgroups, including stage III (HR 0.99, 95% CI 0.40-2.47) and postoperative CEA elevation (HR 1.36, 95% CI 0.45-4.11).

CONCLUSION

High-frequency AP-CT testing is associated with a higher proportion of surgery plus chemo- or radiotherapy as postrecurrence treatment, without improvement in 5-year overall survival.

High resection rates of colorectal liver metastases after standardized follow-up and multimodal management: an outcome study within the COLOFOL trial

BACKGROUND

Outcome after colorectal liver metastases (CRLM) resection has improved over time, despite increased resection rates. Hence, it's crucial to identify all patients possible to treat with curative intent. The objectives of this study were to map recurrence pattern, treatment strategy and survival depending on treatment and follow-up strategy.

METHODS

In the COLOFOL-trial, patients with radically resected stage II-III colorectal cancer were randomized to high-frequency (6, 12, 18, 24 and 36 months; HF) or low-frequency (12 and 36 months; LF) follow-up. In this study, all CRLM within 5 years were identified and medical files scrutinized. Overall survival (OS) was analysed in uni- and multivariable analyses. Primary endpoint was 5-year OS.

RESULTS

Of 2442 patients, 235 (9.6%) developed metachronous CRLM of which 123 (52.3%) underwent treatment with curative intent, resulting in 5-year OS of 58%. Five-year OS for patients with CRLM was 43% after HF versus 24% after LF. The survival benefit was confirmed for HF 8 years from resection of the primary tumour, HR 0.63 (CI 0.46-0.85).

CONCLUSION

A high proportion of metachronous CRLM was possible to treat with curative intent, yielding high survival rates. More intense follow-up after colorectal cancer resection might be of value in high-risk patients.

Endoscopic surveillance after surgery for colorectal cancer

Colorectal cancer (CRC) is one of the most common cancers worldwide and its global incidence is rapidly increasing among adults younger than 50 years, especially in the 20-39 age group. Once a curative resection is achieved, surveillance is mandatory. Colonoscopy has a pivotal role aimed at resecting premalignant neoplasms and detecting cancer at a curable stage. In the current review, an update on the role of surveillance colonoscopy after CRC is provided, considered the most recent international guidelines and evidence published on this issue. In particular, several questions have been answered, why, how and how often colonoscopy should be performed, whether intensive surveillance is more effective than standard surveillance, how endoscopically resected T1 cancer should be followed, the different management existing between colon and rectal cancer, and, finally, how to improve the endoscopic surveillance. In a period of resource constraints, appropriateness will be mandatory, thus understanding how to optimize the role of colonoscopy in the surveillance of patients with a history of CRC is of crucial importance. Improving the quality of colonoscopy and identifying risk factors for recurrent and new-onset CRC, will allow us to individualize the surveillance program while sparing health care cost.

Is a less-intensive follow-up for colon cancer in early stages reasonable?

PURPOSE

Patients with colon cancer are usually included in an intensive 5-year surveillance protocol after curative resection, independent of the tumor stage, though early stages have a considerably lower risk of recurrence. The aim of this study was to analyze the adherence to an intensive follow-up and the risk of recurrence in patients with colon cancer in UICC stages I and II.

METHODS

In this retrospective study, we assessed patients who underwent resection for colon cancer in UICC stages I and II between 2007 and 2016. Data were collected on demographics, tumor stages, therapy, surveillance, recurrent disease, and oncological outcome.

RESULTS

Of the 232 included patients, 43.5% (n = 101) reached the 5-year follow-up disease-free. Seven (7.5%) patients in stage UICC I and sixteen (11.5%) in UICC II had a recurrence, with the highest risk in patients with pT4 (26.3%). A metachronous colon cancer was detected in four patients (1.7%). The therapy of recurrence was intended to be curative in 57.1% (n = 4) of UICC stage I and in 43.8% (n = 7) of UICC stage II, but only in one of seven patients over 80 years. 44.8% (n = 104) of the patients were lost to follow-up.

CONCLUSION

A postoperative surveillance in patients with colon cancer is important and recommended as a recurrent disease can be treated successfully in many patients. However, we suggest that a less intensive surveillance protocol is reasonable for patients with colon cancer in early tumor stages, especially in UICC stage I, as the risk of recurrent disease is low. With elderly and/or frail patients in a reduced general condition, who will not endure further specific therapy in case of a recurrence, the performance of the surveillance should be discussed: we recommend a significant reduction or even renunciation.

Surveillance strategies following curative resection and non-operative approach of rectal cancer: How and how long? Review of current recommendations

Different follow-up strategies are available for patients with rectal cancer following curative treatment. A combination of biochemical testing and imaging investigation, associated with physical examination are commonly used. However, there is currently no consensus about the types of tests to perform, the timing of the testing, and even the need for follow-up at all has been questioned. The aim of this study was to review the evidence of the impact of different follow-up tests and programs in patients with non-metastatic disease after definitive treatment of the primary. A literature review was performed of studies published on MEDLINE, EMBASE, the Cochrane Library and Web of Science up to November 2022. Current published guidelines from the most authoritative specialty societies were also reviewed. According to the follow-up strategies available, the office visit is not efficient but represents the only way to maintain direct contact with the patient and is recommended by all authoritative specialty societies. In colorectal cancer surveillance, carcinoembryonic antigen represents the only established tumor marker. Abdominal and chest computed tomography scan is recommended considering that the liver and lungs are the most common sites of recurrence. Since local relapse in rectal cancer is higher than in colon cancer, endoscopic surveillance is mandatory. Different follow-up regimens have been published but randomized comparisons and meta-analyses do not allow to determine whether intensive or less intensive follow-up had any significant influence on survival and recurrence detection rate. The available data do not allow the drawing of final conclusions on the ideal surveillance methods and the frequency with which they should be applied. It is very useful and urgent for clinicians to identify a cost-effective strategy that allows early identification of recurrence with a special focus for high-risk patients and patients undergoing a “watch and wait” approach.

Oncological surgery follow-up and quality of life: meta-analysis

BACKGROUND

Previous trials found that more intensive postoperative surveillance schedules did not improve survival. Oncological follow-up also provides an opportunity to address psychological issues (for example anxiety, depression, and fear of recurrence). This systematic review assessed the impact of a less intensive surveillance strategy on health-related quality of life (HRQoL), emotional well-being, and patient satisfaction.

METHODS

A systematic search was conducted in PubMed/MEDLINE, Embase, Web of Science, Cochrane database, PsycINFO, and Google Scholar to identify studies comparing different follow-up strategies after oncological surgery and their effect on HRQoL and patient satisfaction, published before 4 May 2022. A meta-analysis was conducted on the most relevant European Organisation for Research and Treatment of Cancer QLQ-C30 and Hospital Anxiety and Depression Scale subscales.

RESULTS

Thirty-five studies were identified, focusing on melanoma (4), colorectal (10), breast (7), prostate (4), upper gastrointestinal (4), gynaecological (3), lung (2), and head and neck (1) cancers. Twenty-two studies were considered to have a low risk of bias, of which 14 showed no significant difference in HRQoL between follow-up approaches. Five studies with a low risk of bias showed improved HRQoL or emotional well-being with a less intensive follow-up approach and three with an intensive approach. Meta-analysis of HRQoL outcomes revealed no negative effects for patients receiving less intensive follow-up.

CONCLUSION

Low-intensity follow-up does not diminish HRQoL, emotional well-being, or patient satisfaction.

Circulating Tumor DNA, Imaging, and Carcinoembryonic Antigen: Comparison of Surveillance Strategies Among Patients Who Underwent Resection of Colorectal Cancer-A Systematic Review and Meta-analysis

BACKGROUND

Almost one-third of colorectal cancer (CRC) patients experience recurrence after resection; nevertheless, follow-up strategies remain controversial. We sought to systematically assess and compare the accuracy of carcinoembryonic antigen (CEA), imaging [positron emission tomography (PET) and computed tomography (CT) scans], and circulating tumor DNA (CtDNA) as surveillance strategies.

PATIENTS AND METHODS

PubMed, Medline, Embase, Scopus, Cochrane, Web of Science, and CINAHL were systematically searched. The Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) was used to assess methodological quality. We performed a bivariate random-effects meta-analysis and reported pooled sensitivity, specificity, and diagnostic odds ratio (DOR) values for each surveillance strategy.

RESULTS

Thirty studies were included in the analysis. PET scans had the highest sensitivity to detect recurrence (0.95; 95%CI 0.91-0.97), followed by CT scans (0.77; 95%CI 0.67-0.85). CtDNA positivity had the highest specificity to detect recurrence (0.95; 95%CI 0.91-0.97), followed by increased CEA levels (0.88; 95%CI 0.82-0.92). Furthermore, PET scans had the highest DOR to detect recurrence (DOR 120.7; 95%CI 48.9-297.9) followed by CtDNA (DOR 37.6; 95%CI 20.8-68.0).

CONCLUSION

PET scans had the highest sensitivity and DOR to detect recurrence, while CtDNA had the highest specificity and second highest DOR. Combinations of traditional cross-sectional/functional imaging and newer platforms such as CtDNA may result in optimized surveillance of patients following resection of CRC.

Follow-up strategy and survival for five common cancers: A meta-analysis

BACKGROUND

This meta-analysis aimed to evaluate the effectiveness of intensive follow-up after curative intent treatment for five common solid tumours, in terms of survival and treatment of recurrences.

METHODS

A systematic literature search was conducted, identifying comparative studies on follow-up for colorectal, lung, breast, upper gastro-intestinal and prostate cancer. Outcomes of interest were overall survival (OS), cancer specific survival (CSS), and treatment of recurrences. Random effects meta-analyses were conducted, with particular focus on studies at low risk of bias.

RESULTS

Fourteen out of 63 studies were considered to be at low risk of bias (8 colorectal, 4 breast, 0 lung, 1 upper gastro-intestinal, 1 prostate). These studies showed no significant impact of intensive follow-up on OS (hazard ratio, 95% confidence interval) for colorectal (0.99; 0.92-1.06), breast 1.06 (0.92-1.23), upper gastro-intestinal (0.78; 0.51-1.19) and prostate cancer (1.00; 0.86-1.16). No impact on CSS (hazard ratio, 95% confidence interval) was found for colorectal cancer (0.94; 0.77-1.16). CSS was not reported for other cancer types. Intensive follow-up increased the rate of curative treatment (relative risk; 95% confidence interval) for colorectal cancer recurrences (1.30; 1.05-1.61), but not for upper gastro-intestinal cancer recurrences (0.92; 0.47-1.81). For the other cancer types, no data on treatment of recurrences was available in low risk studies.

CONCLUSION

For colorectal and breast cancer, high quality studies do not suggest an impact of intensive follow-up strategies on survival. Colorectal cancer recurrences are more often treated locally after intensive follow-up. For other cancer types evaluated, limited high quality research on follow-up is available.

Evaluation of Comparative Surveillance Strategies of Circulating Tumor DNA, Imaging, and Carcinoembryonic Antigen Levels in Patients With Resected Colorectal Cancer

IMPORTANCE

A circulating tumor DNA (ctDNA) assay (Signatera; Natera) has been marketed for use in the surveillance of resected colorectal cancer despite limited data supporting such practice.

OBJECTIVE

To compare a ctDNA assay with standard radiographic imaging and measurement of carcinoembryonic antigen (CEA) levels, per National Comprehensive Cancer Network guidelines, in the surveillance of resected colorectal cancer.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective, single-center cohort study evaluated surveillance strategies of ctDNA, imaging, and measurement of CEA levels in patients with resected colorectal cancer from September 1, 2019, to November 30, 2021.

MAIN OUTCOMES AND MEASURES

The sensitivity and specificity of ctDNA, imaging, measurement of CEA levels, and combination of imaging plus measurement of CEA levels in detecting a confirmed recurrence of colorectal disease. A confirmed recurrence was defined as a positive ctDNA finding or a finding on imaging confirmed by biopsy, CEA level elevation, or subsequent tumor radiographic dynamics.

RESULTS

A total of 48 patients with curatively resected colorectal cancer satisfied the inclusion criteria for this study (28 men [58.3%]; median age, 60 [IQR, 34-85] years) and underwent surveillance by ctDNA, imaging, and measurement of CEA levels. Fifteen patients had disease recurrence during surveillance. Positive ctDNA findings confirmed disease recurrence in 8 patients; imaging, in 9 patients; CEA levels, in 3 patients; and combined imaging plus CEA levels, in 11 patients. Numerically, ctDNA did not perform better than imaging in detecting recurrence, with sensitivities of 53.3% (95% CI, 27.4%-77.7%) and 60.0% (95% CI, 32.9%-82.5%), respectively (P > .99). The combination of imaging plus measurement of CEA levels (sensitivity, 73.3% [95% CI, 44.8%-91.1%]) had a numerical advantage compared with ctDNA in identifying recurrence (P = .55). In addition, no significant difference was noted among ctDNA (median, 14.3 months), imaging (median, 15.0 months), or imaging plus measurement of CEA levels (median, 15.0 months) in the time to identify disease recurrence.

CONCLUSIONS AND RELEVANCE

The findings of this cohort study suggest that ctDNA assay may not provide advantages as a surveillance strategy compared with standard imaging combined with CEA levels when performed per National Comprehensive Cancer Network guidelines.

The utility of surveillance CT scans in a cohort of survivors of colorectal cancer

PURPOSE

Colorectal cancer (CRC) is the third most common cancer worldwide. After curative intent treatment, international guidelines recommend surveillance protocols which include annual CT chest, abdomen and pelvis (CAP) and serum carcinoembryonic antigen (CEA) monitoring which aim to improve overall survival by early detection of recurrence. Despite the widespread recommendations, robust evidence of an overall survival benefit is lacking. Our study aimed to quantify the utility of annual CT CAP as a surveillance modality in comparison to the rate of potentially harmful false-positive and incidental findings.

METHODS

High-risk stage II and stage III CRC patients were retrospectively identified from the Sydney Cancer Survivorship Centre database. Findings on surveillance CT were classified into confirmed recurrence or the potentially harmful findings of (a) false-positive or (b) clinically significant incidental finding.

RESULTS

A total of 376 surveillance CT CAPs were performed in 174 survivors between 12 September 2013 and 30 June 2020. The recurrence rate during the study period was 23/174 (13.2%) with the majority of recurrences detected by abnormal CEA (14/23, 60.9%) versus surveillance CT (4/23, 17.4%), with the remainder identified on non-surveillance CT (5/23, 21.7%). Curative intent surgery was performed in 12/23 people with CRC recurrence. Surveillance CT was shown to result in high levels of false-positive (31/174, 17.8% of patients) or clinically significant incidental findings (30/174, 17.2% of patients). The risk of identifying these potentially harmful findings was ongoing with each year of surveillance CT.

CONCLUSION

Surveillance CT was associated with low detection rates and high rates of potentially harmful findings bringing this surveillance modality under further scrutiny.

IMPLICATIONS FOR CANCER SURVIVORS

An increased emphasis should be placed on educating survivors on the benefits of surveillance CT weighed against the risk of potentially harmful findings.

Reevaluating the Evidence for Intensive Postoperative Extracolonic Surveillance for Nonmetastatic Colorectal Cancer

OBJECTIVES

The FACS, GILDA, and COLOFOL trials have cast doubt on the value of intensive extracolonic surveillance for resected nonmetastatic colorectal cancer and by extension metastasectomy. We reexamined this pessimistic interpretation. We evaluate an alternative explanation: insufficient power to detect a realistically sized survival benefit that may be clinically meaningful.

METHODS

A microsimulation model of postdiagnosis colorectal cancer was constructed assuming an empirically plausible efficacy for metastasectomy and thus surveillance. The model was used to predict the large-sample mortality reduction expected for each trial and the implied statistical power. A potential recurrence imbalance in the FACS trial was investigated. Goodness of fit between model predictions and trial results were evaluated. Downstream life expectancy was estimated and power calculations performed for future trials evaluating surveillance and metastasectomy.

RESULTS

For all 3 trials, the model predicted a mortality reduction of ≤5% and power of <10%. The FACS recurrence imbalance likely led to a large relative bias (>2.5) in the hazard ratio for overall survival favoring control. After adjustment, both COLOFOL and FACS results were consistent with model predictions (P>.5). A 2.6 (95% credible interval 0.5-5.1) and 3.6 (95% credible interval 0.8-7.0) month increase in life expectancy is predicted comparing intensive extracolonic surveillance-routine computed tomography scans and carcinoembryonic antigen assays-with 1 computed tomography scan at 12 months or no surveillance, respectively. An adequately sized surveillance trial is not feasible. A metastasectomy trial should randomize at least 200 to 300 patients.

CONCLUSIONS

Recent trial results do not warrant de novo skepticism of metastasectomy nor targeted extracolonic surveillance. Given the potential for clinically meaningful life-expectancy gain and significant uncertainty, a trial of metastasectomy is needed.

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.

Optimal postoperative surveillance strategies for stage III colorectal cancer

BACKGROUND

Optimal surveillance strategies for stage III colorectal cancer (CRC) are lacking, and intensive surveillance has not conferred a significant survival benefit.

AIM

To examine the association between surveillance intensity and recurrence and survival rates in patients with stage III CRC.

METHODS

Data from patients with pathologic stage III CRC who underwent radical surgery between January 2005 and December 2012 at Asan Medical Center, Seoul, Korea were retrospectively reviewed. Surveillance consisted of abdominopelvic computed tomography (CT) every 6 mo and chest CT annually during the 5 year follow-up period, resulting in an average of three imaging studies per year. Patients who underwent more than the average number of imaging studies annually were categorized as high intensity (HI), and those with less than the average were categorized as low intensity (LI).

RESULTS

Among 1888 patients, 864 (45.8%) were in HI group. Age, sex, and location were not different between groups. HI group had more advanced T and N stage (P = 0.002, 0.010, each). Perineural invasion (PNI) was more identified in the HI group (21.4% vs 30.3%, P < 0.001). The mean overall survival (OS) and recurrence-free interval (RFI) was longer in the LI group (P < 0.001, each). Multivariate analysis indicated that surveillance intensity [odds ratio (OR) = 1.999; 95% confidence interval (CI): 1.680-2.377; P < 0.001], pathologic T stage (OR = 1.596; 95%CI: 1.197-2.127; P = 0.001), PNI (OR = 1.431; 95%CI: 1.192-1.719; P < 0.001), and circumferential resection margin (OR = 1.565; 95%CI: 1.083-2.262; P = 0.017) in rectal cancer were significantly associated with RFI. The mean post-recurrence survival (PRS) was longer in patients who received curative resection (P < 0.001). Curative resection rate of recurrence was not different between HI (29.3%) and LI (23.8%) groups (P = 0.160). PRS did not differ according to surveillance intensity (P = 0.802).

CONCLUSION

Frequent surveillance with CT scan do not improve OS in stage III CRC patients. We need to evaluate role of other surveillance method rather than frequent CT scans to detect recurrence for which curative treatment was possible because curative resection is the important to improve post-recurrence survival.

Clinical Applications of Minimal Residual Disease Assessments by Tumor-Informed and Tumor-Uninformed Circulating Tumor DNA in Colorectal Cancer

Simple Summary

Circulating tumor DNA, or ctDNA, are fragments of tumor DNA that can be detected in the blood of patients with colorectal cancer. Measuring ctDNA levels in the blood has shown the potential to provide important information that can be helpful in the clinical care of patients with colorectal cancer. For example, in patients with colon cancer that has been removed by surgery, measuring ctDNA in the blood can predict the likelihood of cancer recurrence, while in those with metastatic colorectal cancer, measuring ctDNA can inform the clinician whether chemotherapy is effective at earlier timepoints than currently available tests. In this review, we discuss the results from ongoing studies describing the utility of ctDNA measurements across all stages of colorectal cancer. We also discuss the various clinical scenarios that ctDNA may have the most immediate impact in colorectal cancer management.

Abstract

Emerging data suggest that circulating tumor DNA (ctDNA) can detect colorectal cancer (CRC)-specific signals across both non-metastatic and metastatic settings. With the development of multiple platforms, including tumor-informed and tumor-agnostic ctDNA assays and demonstration of their provocative analytic performance to detect minimal residual disease, there are now ongoing, phase III randomized clinical trials to evaluate their role in the management paradigm of CRC. In this review, we highlight landmark studies that have formed the basis for ongoing studies on the clinically applicability of plasma ctDNA assays in resected, stage I–III CRC and metastatic CRC. We discuss clinical settings by which ctDNA may have the most immediate impact in routine clinical practice. These include the potential for ctDNA to (1) guide surveillance and intensification or de-intensification strategies of adjuvant therapy in resected, stage I–III CRC, (2) predict treatment response to neoadjuvant therapy in locally advanced rectal cancer inclusive of total neoadjuvant therapy (TNT), and (3) predict response to systemic and surgical therapies in metastatic disease. We end by considering clinical variables that can influence our ability to reliably interpret ctDNA dynamics in the clinic.

Stage dependent recurrence patterns and post-recurrence outcomes in non-metastatic colon cancer

BACKGROUND

Multiple meta-analyses have demonstrated that routine surveillance following colorectal cancer surgery improves survival outcomes. There is limited data on how recurrence patterns and post-recurrence outcomes vary by individual tumor stage.

METHODS

Using a multi-site community cohort study, we examined the potential impact of primary tumor stage on the sites of recurrence, management of recurrent disease with curative intent, and post-resection survival. We also explored changes over time.

RESULTS

Of 4257 new colon cancers diagnosed 2001 through 2016, 789 (21.1%) had stage I, 1584 (42.4%) had stage II, and 1360 (36.4%) had stage III colon cancer. For consecutive 5-year periods (2001-2005, 2006-2010, 2011-2016), recurrence rates have declined (23.4 vs. 17.1 vs. 13.6%, p < 0.001), however, the resection rates of metastatic disease (29.3 vs. 38.6 vs. 35.0%, p = 0.21) and post-resection 5-year survival (52.0 vs. 51.8 vs. 64.2%, p = 0.12) have remained steady. Primary tumor stage impacted recurrence rate (3.8 vs. 12 vs. 28%, p < 0.0001 for stage 1, 2, and 3), patterns of recurrence, resection of metastatic disease, (50 vs. 42 vs. 30%, p < 0.0001) and post-resection 5-year survival (92 vs. 64 vs. 44%, p < 0.001).

CONCLUSION

In this community cohort we defined significant differences in recurrence patterns and post-resection survival by tumor stage, with a diminishing rate of recurrence over time. While recurrence rates were lower with stage I and II disease, the high rate of metastatic disease resection and excellent post-resection outcomes help to justify routine surveillance in these patients.

Association of Adherence to Quality Metrics with Recurrence or Mortality among Veterans with Colorectal Cancer

BACKGROUND

The National Comprehensive Cancer Network has defined metrics for colorectal cancer; however, the association of metric adherence with patient clinical outcomes remains underexplored. The study aim was to evaluate the association of National Comprehensive Cancer Network metric adherence with recurrence and mortality in Veterans with nonmetastatic colorectal cancer.

METHODS

Veterans with stage I-III colorectal cancer who underwent non-emergent resection from 2001 to 2015 at a single Veterans Affairs Medical Center were included. The primary predictor was completion of eligible National Comprehensive Cancer Network metrics. The primary outcome was a composite of recurrence or all-cause death in three phases of care: surgical (up to 6 months after resection), treatment (6-18 months after resection), and surveillance (18 months-3 years after resection). Hazard ratios were estimated via Cox proportional hazards regression in a propensity score-weighted cohort.

RESULTS

A total of 1107 electronic medical records of patients undergoing colorectal surgery were reviewed, and 379 patients were included (301 colon and 78 rectal cancer). In the surgical phase, the weighted analysis yielded a hazard ratio of 0.37 (95% confidence interval 0.12-1.13) for metric-adherent patients compared with non-adherent patients. In the treatment and surveillance phases, the hazard ratios for metric-adherent care were 0.68 (95% confidence interval 0.25-1.85) and 0.91 (95% confidence interval 0.31-2.68), respectively.

CONCLUSIONS

The National Comprehensive Cancer Network guideline metric adherence was associated with a lower rate of recurrence and death in the surgical phase of care among stage I-III patients with resected colorectal cancer.

Patterns and resectability of colorectal cancer recurrences: outcome study within the COLOFOL trial

BACKGROUND

Improvements in surgery, imaging, adjuvant treatment, and management of metastatic disease have led to modification of previous approaches regarding the risk of recurrence and prognosis in colorectal cancer. The aims of this study were to map patterns, risk factors, and the possibility of curative treatment of recurrent colorectal cancer in a multimodal setting.

METHODS

This was a cohort study based on the COLOFOL trial population of patients who underwent radical resection of stage II or III colorectal cancer. The medical files of all patients with recurrence within 5 years after resection of the primary tumour were scrutinized. Follow-up time was 5 years after the first recurrence. Primary endpoints were cumulative incidence, site, timing, and risk factors for recurrence, and rate of potentially curative treatment. A secondary endpoint was survival.

RESULTS

Of 2442 patients, 471 developed recurrences. The 5-year cumulative incidence was 21.4 (95 per cent c.i. 19.5 to 23.3) per cent. The median time to detection was 1.1 years after surgery and 87.3 per cent were detected within 3 years. Some 98.2 per cent of patients who had potentially curative treatment were assessed by a multidisciplinary tumour board. A total of 47.8 per cent of the recurrences were potentially curatively treated. The 5-year overall survival rate after detection was 32.0 (95 per cent c.i. 27.9 to 36.3) per cent for all patients with recurrence, 58.6 (51.9 to 64.7) per cent in the potentially curatively treated group and 7.7 (4.8 to 11.5) per cent in the palliatively treated group.

CONCLUSION

Time to recurrence was similar to previous results, whereas the 21.4 per cent risk of recurrence was somewhat lower. The high proportion of patients who received potentially curative treatment, linked to a 5-year overall survival rate of 58.6 per cent, indicates that it is possible to achieve good results in recurrent colorectal cancer following multidisciplinary assessment.

Optimal Postoperative Surveillance Strategies for Colorectal Cancer: A Retrospective Observational Study

This study aimed to assess whether surveillance intensity is associated with recurrence and survival in colorectal cancer (CRC) patients. Overall, 3794 patients with pathologic stage I-III CRC who underwent radical surgery between January 2012 and December 2014 were examined. Surveillance comprised abdominopelvic computed tomography (CT) every 6 months and chest CT annually for 5 years. Patients who underwent more than and less than an average of three imaging examinations annually were assigned to the high-intensity (HI) and low-intensity (LI) groups, respectively. Demographics were similar in both groups. T and N stages were higher and perineural and lymphovascular invasion were more frequent in the HI group (p < 0.001 each). The mean overall survival (OS) was similar for both groups; however, recurrence-free survival (RFS) was longer (p < 0.001) and post-recurrence survival (PRS) was shorter (p = 0.024) in the LI group. In the multivariate analysis, surveillance intensity was associated with RFS (p < 0.001) in contrast to PRS (p = 0.731). In patients with high recurrence risk predicted using the nomogram, OS was longer in the HI group (p < 0.001). A higher imaging frequency in patients at high risk of recurrence could be expected to lead to a slight increase in PRS but does not improve OS. Therefore, rather than increasing the number of CT scans in high-risk patients, other imaging modalities or innovative approaches, such as liquid biopsy, are required.

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.

Radiological Surveillance Post-Curative Colorectal Cancer Resection: Is There a Need for a Targeted Protocol?

Background

The frequency of radiological surveillance after curative colorectal cancer resection has long been a controversial issue with the need to balance potential harm from ionizing radiation and the financial burden of intense surveillance against advantages of early detection of recurrent disease. NICE guidelines issued in 2018 suggested having two surveillance computed tomography (CT) scans within three years of surgery without specifying the timing or the interval.

Aim

To examine whether an evidence-based flexible approach based on individual patients’ risk factors can add value to surveillance protocols. Reaching a targeted protocol that can maximize early detection of metastasis without consumption of resources and most important without compromising patient safety.

Methodology

A retrospective study involving five years of data of patients who underwent curative colorectal cancer resections. Data extracted after patients completed their three-year surveillance CT scans, CT reports retrieved together with post-operative histology reports, and a detailed database was constructed.

Results

Of 179 patients included, 66 developed recurrence (7 local and 59 distant). Recurrence increased from 23.5% in T1 to 66% in T4 (P=0.0001). The median time to recurrence 23 months in T4 disease compared to 36, 42 and 43 months for stages T1, T2 and T3, respectively (P=0.0001). A similar incremental increase in recurrence noted from 22% in the N0 stage to 73.5% in the N2 stage (P=0.0001); the median time to recurrence of 14 months in N2 patients compared to 45 and 33 months for stages N0 and N1, respectively (P=0.0001). Recurrence correlated well with positive extramural vascular invasion (EMVI) status, (71.7% versus 19.3% P=0.0001) being detected significantly earlier in EMVI positive group at 17 versus 45 months (P=0.0001).

Conclusion

Flexible protocol for radiological surveillance after curative resection of colorectal cancer, based on known pathological prognostic factors, is likely to be more effective in maximizing resource utilization as well as improving patient outcomes.

Diagnostic accuracy of follow-up tests for detecting colorectal cancer recurrences in primary care: A systematic review and meta-analysis

Introduction

Traditionally, follow‐up of colorectal cancer (CRC) is performed in secondary care. In new models of care, the screening part care could be replaced to primary care. We aimed to synthesise evidence on the diagnostic accuracy of commonly used screeners in CRC follow‐up applicable in primary care: carcinoembryonic antigen (CEA), ultrasound and physical examination.

Methods

Medline, EMBASE, Cochrane Trial Register and Web of Science databases were systematically searched. Studies were included if they provided sufficient data for a 2 × 2 contingency tables. QUADAS‐2 was used to assess methodological quality. We performed bivariate random effects meta‐analysis, generated a hypothetical cohort, and reported sensitivity and specificity.

Results

We included 12 studies (n = 3223, median recurrence rate 19.6%). Pooled estimates showed a sensitivity for CEA (≤ 5 μg/l) of 59% [47%–70%] and a specificity of 89% [80%–95%]. Only few studies reported sensitivities and specificities for ultrasound (36–70% and 97–100%, respectively) and clinical examination (23% and 27%, respectively).

Conclusion

In practice, GPs could perform CEA screening. Radiological examination in a hospital setting should remain part of the surveillance strategy. Personalised algorithms accounting for recurrence risk and changes of CEA‐values over time might add to the diagnostic value of CEA in primary care.

Frequent post-operative monitoring of colorectal cancer using individualised ctDNA validated by multiregional molecular profiling

Background

Circulating tumour DNA (ctDNA) is known as a tumour-specific personalised biomarker, but the mutation-selection criteria from heterogeneous tumours remain a challenge.

Methods

We conducted multiregional sequencing of 42 specimens from 14 colorectal tumours of 12 patients, including two double-cancer cases, to identify mutational heterogeneity to develop personalised ctDNA assays using 175 plasma samples.

Results

“Founder” mutations, defined as a mutation that is present in all regions of the tumour in a binary manner (i.e., present or absent), were identified in 12/14 tumours. In contrast, “truncal” mutations, which are the first mutation that occurs prior to the divergence of branches in the phylogenetic tree using variant allele frequency (VAF) as continuous variables, were identified in 12/14 tumours. Two tumours without founder and truncal mutations were hypermutators. Most founder and truncal mutations exhibited higher VAFs than “non-founder” and “branch” mutations, resulting in a high chance to be detected in ctDNA. In post-operative long-term observation for 10/12 patients, early relapse prediction, treatment efficacy and non-relapse corroboration were achievable from frequent ctDNA monitoring.

Conclusions

A single biopsy is sufficient to develop custom dPCR probes for monitoring tumour burden in most CRC patients. However, it may not be effective for those with hypermutated tumours.

Published randomized controlled trials of surveillance in cancer patients - a systematic review

With solid tumor cancer survivorship increasing, the number of patients requiring post-treatment surveillance also continues to increase. This highlights the need for evidence-based cancer surveillance guidelines. Ideally, these guidelines would be based on combined high-quality data from randomized controlled trials (RCTs). We present a systematic review of published cancer surveillance RCTs in which we sought to determine the feasibility of data pooling for guideline development. We carried out a systematic search of medical databases for RCTs in which adult patients with solid tumors that had undergone surgical resection with curative intent and had no metastatic disease at presentation, were randomized to different surveillance regimens that assessed effectiveness on overall survival (OS). We extracted study characteristics and primary and secondary outcomes, and assessed risk of bias and validity of evidence with standardized checklist tools. Our search yielded 32,216 articles for review and 18 distinct RCTs were included in the systematic review. The 18 trials resulted in 23 comparisons of surveillance regimens. There was a highlevel of variation between RCTs, including the study populations evaluated, interventions assessed and follow-up periods for the primary outcome. Most studies evaluated colorectal cancer patients (11/18, [61%]). The risk of bias and validity of evidence were variable and inconsistent across studies. This review demonstrated that there is tremendous heterogeneity among RCTs that evaluate effectiveness of different postoperative surveillance regimens in cancer patients, rendering the consolidation of data to inform high-quality cancer surveillance guidelines unfeasible. Future RCTs in the field should focus on consistent methodology and primary outcome definition.

Second primary cancers and recurrence in patients after resection of colorectal cancer: An integrated analysis of trials by Japan Clinical Oncology Group: JCOG1702A

BACKGROUND

Improvements in early detection and treatment have resulted in an increasing number of long-term survivors of colorectal cancer (CRC). For the survivors, second primary cancer and recurrence are important issues; however, evidence for an appropriate surveillance strategy remains limited.This study aimed to investigate the frequency and timing of second primary cancer in patients after surgery for exploring an appropriate surveillance strategy by using an integrated analysis of three large-scale randomized controlled trials in Japan.

METHODS

The eligibility criteria of three trials included histologically confirmed CRC and having received surgery. The timing, site and frequency of second primary cancers and recurrence were investigated. Risk factors associated with second primary cancers were also examined. The standardized incidence ratio (SIR) of second primary cancers compared with the national database of the Japan Cancer Registry was estimated.

RESULTS

A total of 2824 patients were included in this study. The cumulative incidence of second primary cancer increased over time. The SIR of any second primary cancer was 1.07 (95% CI: 0.94-1.21). The SIR for second primary cancers of colon was 1.09 (95% CI: 0.79-1.47). The cumulative incidence of recurrence almost reached plateau at 3 years.

CONCLUSIONS

A common surveillance strategy for the general population can be applied even for curatively resected CRC patients, as the risk of second primary cancers was almost the same as that of the general population.

Comparison of 18FDG-PET/CT and conventional follow-up methods in colorectal cancer: A randomised prospective study

BACKGROUND

A surveillance program was performed in colorectal cancer (CRC) patients after surgery, to diagnose asymptomatic recurrence.

AIMS

To assess whether 18-FDG positron emission tomography/CT (PET/CT) improved the detection of recurrence during a 3-year follow-up.

METHODS

A multicentre, two-arm randomised prospective trial comparing different 36-month follow-up strategies. Complete colonoscopy was performed at baseline and after 3 years and clinical exams with imaging every 3 months. The conventional arm (A) received carcinoembryonic antigen, liver echography, and alternated between lung radiography and computed tomography (CT) scans. The experimental arm (B) received PET/CT.

RESULTS

A total of 365 patients with colon (79.4%) or rectal cancer (20.6%), stages II (48.2%) or III (50.8%), were enroled in this study. At 36 months, intention-to-treat analysis revealed recurrence in 31 (17.2%) patients in arm A and 47 (25.4%) in arm B (p = 0.063). At 3 years, 7 of 31 relapses (22.5%) in arm A were surgically treated with curative intent, compared to 17 of 47 (36.2%) in arm B (p = 0.25). The rates of recurrence and new cancers were higher in arm B than arm A (p = 0.038).

CONCLUSIONS

PET/CT follow-up every 6 months did not increase the rate of recurrence at 3 years or the rate of surgically treated recurrence compared with conventional follow-up.

Characteristics Associated With Nonreceipt of Surveillance Testing and the Relationship With Survival in Stage II and III Colon Cancer

We investigated characteristics of patients with colon cancer that predicted nonreceipt of posttreatment surveillance testing and the subsequent associations between surveillance status and survival outcomes. This was a retrospective cohort study of the Surveillance, Epidemiology, and End Results database combined with Medicare claims. Patients diagnosed between 2002 and 2009 with disease stages II and III and who were between 66 and 84 years of age were eligible. A minimum of 3 years' follow-up was required, and patients were categorized as having received any surveillance testing (any testing) versus none (no testing). Poisson regression was used to obtain risk ratios with 95% confidence intervals for the relative likelihood of No Testing. Cox models were used to obtain subdistribution hazard ratios with 95% confidence intervals for 5- and 10-year cancer-specific and noncancer deaths. There were 16,009 colon cancer cases analyzed. Patient characteristics that predicted No Testing included older age, Black race, stage III disease, and chemotherapy. Patients in the No Testing group had an increased rate of 10-year cancer death that was greater for patients with stage III disease (subdistribution hazard ratio = 1.79, 95% confidence interval: 1.48, 2.17) than those with stage II disease (subdistribution hazard ratio = 1.41, 95% confidence interval: 1.19, 1.66). Greater efforts are needed to ensure all patients receive the highest quality medical care after diagnosis of colon cancer.

ctDNA and Adjuvant Therapy for Colorectal Cancer: Time to Re-Invent Our Treatment Paradigm

Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide. While there have been significant developments in the treatments for patients with metastatic CRC in recent years, improving outcomes in the adjuvant setting has been more challenging. Recent technological advances in circulating tumour DNA (ctDNA) assay with the ability to detect minimal residual disease (MRD) after curative intent surgery will fundamentally change how we assess recurrence risk and conduct adjuvant trials. Studies in non-metastatic CRC have now demonstrated the prognostic impact of ctDNA analysis after curative intent surgery over and above current standard of care clinicopathological criteria. This ability of ctDNA analysis to stratify patients into low- and very-high-risk groups provides a window of opportunity to personalise adjuvant treatment where escalation/de-escalation of adjuvant systemic therapy could potentially increase cure rates and also reduce treatment-related physical and financial toxicity. Emerging data suggest that conversion of ctDNA from detectable to undetectable after adjuvant chemotherapy may reflect treatment efficacy. This real-time assessment of treatment benefit could be used as a surrogate endpoint for adjuvant novel drug development. Several ctDNA-based randomized adjuvant trials are ongoing internationally to confirm the clinical utility of ctDNA in colorectal cancer.

Circulating Tumor DNA Predicts Pathologic and Clinical Outcomes Following Neoadjuvant Chemoradiation and Surgery for Patients With Locally Advanced Rectal Cancer

PURPOSE

This study was designed to assess the ability of perioperative circulating tumor DNA (ctDNA) to predict surgical outcome and recurrence following neoadjuvant chemoradiation for locally advanced rectal cancer (LARC).

MATERIALS AND METHODS

Twenty-nine patients with newly diagnosed LARC treated between January 2014 and February 2018 were enrolled. Patients received long-course neoadjuvant chemoradiation prior to surgery. Plasma ctDNA was collected at baseline, preoperatively, and postoperatively. Next-generation sequencing was used to identify mutations in the primary tumor, and mutation-specific droplet digital polymerase chain reaction was used to assess mutation fraction in ctDNA.

RESULTS

The median age was 54 years. The overall margin-negative, node-negative resection rate was 73% and was significantly higher among patients with undetectable preoperative ctDNA (n = 17, 88%) versus patients with detectable preoperative ctDNA (n = 9, 44%; P = .028). Undetectable ctDNA was also associated with more favorable neoadjuvant rectal scores (univariate linear regression, P = .029). Recurrence-free survival (RFS) was calculated for the subset (n = 19) who both underwent surgery and had postoperative ctDNA available. At a median follow-up of 20 months, patients with detectable postoperative ctDNA experienced poorer RFS (hazard ratio, 11.56; P = .007). All patients (4 of 4) with detectable postoperative ctDNA recurred (positive predictive value = 100%), whereas only 2 of 15 patients with undetectable ctDNA recurred (negative predictive value = 87%).

CONCLUSION

Among patients treated with neoadjuvant chemoradiation for LARC, patients with undetectable preoperative ctDNA were more likely to have a favorable surgical outcome as measured by the rate of margin-negative, node-negative resections and neoadjuvant rectal score. Furthermore, we have confirmed prior reports indicating that detectable postoperative ctDNA is associated with worse RFS. Future prospective study is needed to assess the potential for ctDNA to assist with personalizing treatment for LARC.

Intratumoural immune signature to identify patients with primary colorectal cancer who do not require follow-up after resection: an observational study

BACKGROUND

Following surgical and adjuvant treatment of primary colorectal cancer, many patients are routinely followed up with axial imaging (most commonly computerised tomography imaging) and blood carcinoembryonic antigen (a tumour marker) testing. Because fewer than one-fifth of patients will relapse, a large number of patients are followed up unnecessarily.

OBJECTIVES

To determine whether or not the intratumoural immune signature could identify a cohort of patients with a relapse rate so low that follow-up is unnecessary.

DESIGN

An observational study based on a secondary tissue collection of the tumours from participants in the FACS (Follow-up After Colorectal Cancer Surgery) trial.

SETTING AND PARTICIPANTS

Formalin-fixed paraffin-embedded tumour tissue was obtained from 550 out of 1202 participants in the FACS trial. Tissue microarrays were constructed and stained for cluster of differentiation (CD)3+ and CD45RO+ T lymphocytes as well as standard haematoxylin and eosin staining, with a view to manual and, subsequently, automated cell counting.

RESULTS

The tissue microarrays were satisfactorily stained for the two immune markers. Manual cell counting proved possible on the arrays, but manually counting the number of cores for the entire study was found to not be feasible; therefore, an attempt was made to use automatic cell counting. Although it is clear that this approach is workable, there were both hardware and software problems; therefore, reliable data could not be obtained within the time frame of the study.

LIMITATIONS

The main limitations were the inability to use machine counting because of problems with both hardware and software, and the loss of critical scientific staff. Findings from this research indicate that this approach will be able to count intratumoural immune cells in the long term, but whether or not the original aim of the project proved possible is not known.

CONCLUSIONS

The project was not successful in its aim because of the failure to achieve a reliable counting system.

FUTURE WORK

Further work is needed to perfect immune cell machine counting and then complete the objectives of this study that are still relevant.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN41458548.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 2. See the NIHR Journals Library website for further project information.

Risk Stratification Based on Synchronous Neoplasia and Clinical Physicochemical Characteristics Predicts a Higher Incidence of Metachronous Advanced Neoplasia in Patients Undergoing Colorectal Resection for Colorectal Cancer

Purpose

Patients who undergo primary colorectal cancer (CRC) resection remain at increased risk for metachronous advanced neoplasia (MAN) in the remnant colorectum. This study aimed to investigate the incidence and clinicopathological characteristics predictive of MAN development in the residual colon after surgery.

Patients and Methods

We retrospectively reviewed 450 primary CRC cases referred to our hospital during a 4-year period. Univariate and multivariate analyses were performed to identify risk factors for MAN. The cumulative incidence of MAN was evaluated by the Cox proportional hazards model.

Results

MAN development was confirmed in 78 of the 450 patients (17.3%). Overall 1-, 2-, 3-, and 5-year cumulative probabilities were 0.9%, 4.8%, 9.8%, and 16.1%, respectively, for MAN. Among the clinical and colonoscopic factors at baseline, the independent factors that were significantly associated with MAN were synchronous neoplasia, carcinoembryonic antigen (CEA) level ≥10.0 ng/mL, and index cancer size ≥50 mm. The cumulative probability of MAN was significantly higher for patients with synchronous advanced neoplasia (SAN) than for those without synchronous neoplasia (P = 0.000). A subgroup analysis of patients based on the CEA level and index cancer size indicated that CEA ≥10 ng/mL and index cancer ≥50 mm resulted in a significantly higher cumulative probability of MAN (P = 0.039).

Conclusion

Patients with SAN or high preoperative serum CEA levels and large index cancer are at increased risk for early-onset MAN. More intensive surveillance strategies may be appropriate for these groups. Risk stratification based on synchronous neoplasia and clinical physicochemical characteristics requires further investigations involving modified appropriate postoperative colonoscopic surveillance schedules.

Recurrence Risk after Radical Colorectal Cancer Surgery-Less Than before, But How High Is It?

Simple Summary

Evidence indicates that recurrence risk after colon cancer today is less than it was when trials performed decades ago showed that adjuvant chemotherapy reduces the risk and prolong disease-free and overall survival. After rectal cancer surgery, local recurrence rates have decreased but it is unclear if systemic recurrences have. After a systematic review of available literature reporting recurrence risks after curative colorectal cancer surgery we report that the risks are lower today than they were in the past and that this risk reduction is not solely ascribed to the use of adjuvant therapy. Adjuvant therapy always means overtreatment of many patients, already cured by the surgery. Fewer recurrences mean that progress in the care of these patients has happened but also that the present guidelines giving recommendations based upon old data must be adjusted. The relative gains from adding chemotherapy are not altered, but the absolute number of patients gaining is less.

Abstract

Adjuvant chemotherapy aims at eradicating tumour cells sometimes present after radical surgery for a colorectal cancer (CRC) and thereby diminish the recurrence rate and prolong time to recurrence (TTR). Remaining tumour cells will lead to recurrent disease that is usually fatal. Adjuvant therapy is administered based upon the estimated recurrence risk, which in turn defines the need for this treatment. This systematic overview aims at describing whether the need has decreased since trials showing that adjuvant chemotherapy provides benefits in colon cancer were performed decades ago. Thanks to other improvements than the administration of adjuvant chemotherapy, such as better staging, improved surgery, the use of radiotherapy and more careful pathology, recurrence risks have decreased. Methodological difficulties including intertrial comparisons decades apart and the present selective use of adjuvant therapy prevent an accurate estimate of the magnitude of the decreased need. Furthermore, most trials do not report recurrence rates or TTR, only disease-free and overall survival (DFS/OS). Fewer colon cancer patients, particularly in stage II but also in stage III, today display a sufficient need for adjuvant treatment considering the burden of treatment, especially when oxaliplatin is added. In rectal cancer, neo-adjuvant treatment will be increasingly used, diminishing the need for adjuvant treatment.

Impact of Surgical Resection on Metachronous Metastases of Colorectal Cancer According to Tumor Doubling Time

BACKGROUND/AIM

We aimed to elucidate the prognostic impact of tumor doubling time (DT) and radical surgery when classified by DT in patients with metachronous liver, lung, or peritoneal metastases of colorectal cancer (CRC).

PATIENTS AND METHODS

We reviewed the data of 1941 patients who underwent curative surgery for CRC and calculated DT for recurrences using computed tomography.

RESULTS

Short DT was an independent prognostic risk factor in liver (p<0.001) and peritoneal (p=0.03) metastases. Survival was significantly better in patients who underwent surgery than in those who did not, both in short and long DT groups in any metastatic organ (p<0.01). Patients with long DT gained significantly better prognostic benefit from surgery than those with short DT in liver (p=0.01) and peritoneal (p=0.04) metastases.

CONCLUSION

Surgery is recommended for resectable metastases, especially in patients with liver and peritoneal metastases with long DT.

Is It Time to Introduce PET/CT in Rectal Cancer Guidelines?

At the moment, international guidelines for rectal cancer suggest to consider F-FDG PET/CT scan in a few conditions: (1) at disease presentation in case of suspected or proven metastatic synchronous adenocarcinoma with potentially curable M1 disease; (2) in the recurrence workup for serial carcinoembryonic antigen level elevation; (3) in the recurrence workup with metachronous metastases documented by CT, MRI, or biopsy; (4) in case of strong contraindication to IV contrast agent administration; and (5) to evaluate an equivocal finding on a contrast-enhanced CT or MRI. PET/CT is not indicated in the follow-up or surveillance of rectal cancer. On the other hand, an attentive evaluation of the literature shows that PET/CT may also be used in some circumstances with significant levels of diagnostic accuracy. This review article aims to emphasize differences between current international guidelines and scientific literature in the role of PET/CT in rectal cancer.

Is It Time to Introduce PET/CT in Colon Cancer Guidelines?

International colon cancer guidelines suggest F-FDG PET/CT in a few circumstances: (1) at disease presentation in case of suspected or proven metastatic synchronous adenocarcinoma; (2) in the workup of recurrent colon cancer with metachronous metastases documented by CT, MRI, or biopsy and in case of serial CEA elevation with negative colonoscopy and negative CT; and (3) in case of contraindication to iodine- and gadolinium-based contrast agents. However, review of the literature has shown that PET/CT can also be used in other scenarios with significant levels of diagnostic advantage. This review aims to emphasize differences between guidelines and scientific literature for the use of PET/CT in colon cancer.

Pulmonary Metastasectomy in Colorectal Cancer: updated analysis of 93 randomized patients - control survival is much better than previously assumed

AIM

Lung metastases from colorectal cancer are resected in selected patients in the belief that this confers a significant survival advantage. It is generally assumed that the 5-year survival of these patients would be near zero without metastasectomy. We tested the clinical effectiveness of this practice in Pulmonary Metastasectomy in Colorectal Cancer (PulMiCC), a randomized, controlled noninferiority trial.

METHOD

Multidisciplinary teams in 14 hospitals recruited patients with resectable lung metastases into a two-arm trial. Randomization was remote and stratified according to site, with minimization for age, sex, primary cancer stage, interval since primary resection, prior liver involvement, number of metastases and carcinoembryonic antigen level. The trial management group was blind to patient allocation until after intention-to-treat analysis.

RESULTS

From 2010 to 2016, 93 participants were randomized. These patients were 35-86 years of age and had between one and six lung metastases at a median of 2.7 years after colorectal cancer resection; 29% had prior liver metastasectomy. The patient groups were well matched and the characteristics of these groups were similar to those of observational studies. The median survival after metastasectomy was 3.5 (95% CI: 3.1-6.6) years compared with 3.8 (95% CI: 3.1-4.6) years for controls. The estimated unadjusted hazard ratio for death within 5 years, comparing the metastasectomy group with the control group, was 0.93 (95% CI: 0.56-1.56). Use of chemotherapy or local ablation was infrequent and similar in each group.

CONCLUSION

Patients in the control group (who did not undergo lung metastasectomy) have better survival than is assumed. Survival in the metastasectomy group is comparable with the many single-arm follow-up studies. The groups were well matched with features similar to those reported in case series.

Less intensive surveillance after radical surgery for stage I-III colorectal cancer by focusing on the doubling time of recurrence

PURPOSE

To propose a new and improved surveillance schedule for colorectal cancer (CRC) patients by focusing on the recurrence rate, resectability, and especially, the tumor doubling time (DT) of recurrent tumors.

METHODS

The subjects of this retrospective review were 1774 consecutive patients who underwent radical surgery for stage I-III CRC between January, 2004 and December, 2015. We calculated the DT by measuring the tumor diameter using computed tomography (CT).

RESULTS

The median DT for recurrences in the liver, lung, peritoneum, and other locations were 35, 72, 85, and 36 days, respectively, (p < 0.001) and tumor growth rates differed according to the organs where recurrence developed. Multiple linear regression analysis showed that the DT was strongly associated with the relapse-free interval from primary surgery (p < 0.001), and that the DT in patients with recurrence detected ≥ 3 years after primary surgery was longer by 151.1 days than that in patients with recurrence detected within 1 year after primary surgery. We proposed a less intensive surveillance, which achieved an average cost reduction of 32.5% compared with conventional surveillance in Japan.

CONCLUSION

We propose a new and more cost-efficient surveillance schedule for CRC surgery patients in the clinical setting.

Comprehensive literature review of randomized clinical trials examining novel treatment advances in patients with colon cancer

The treatment of colon cancer has had numerous recent advances, in terms of surgical approach, adjuvant therapies, and more. In this review, the authors examine randomized clinical trials comparing open surgery to laparoscopic surgery (including total mesocolic excision), and also examine the role of robotic surgery. Novel surgical techniques including the no-touch technique, side-to-side anastomosis, suture technique, complete mesocolic excision (CME) with central vascular ligation (CVL), and natural orifice transluminal endoscopic surgery (NOTES) are outlined. The role of placing endoscopic self-expandable metal stents (SEMS) for colonic obstruction is compared and contrasted with the surgical approach, and the effect that the anti-VEGF inhibitor bevacizumab may have on this side effect profile is further explored. The role of the resection of the primary tumor in the setting of metastatic disease is examined with respect to survival benefit. Pathways of perioperative care which can accelerate post-surgical recovery, including enhanced recovery after surgery (ERAS) are examined. The role of adjuvant chemotherapy in patients with high-risk stage II and patients with stage III disease is examined, along with the role on circulating tumor DNA (ctDNA) as well as with the biologic targeted agents cetuximab and bevacizumab. Lastly, the authors detail the postoperative surveillance schedules after surgical resection with respect to survival outcomes.

Virtual Colorectal Cancer Surveillance: Bringing Scope Rate to Target

BACKGROUND

Although endoscopy is recommended at 1 year after colorectal cancer (CRC) resection to detect locally recurrent CRC, earlier work at our Veterans Affairs (VA) facility demonstrated that 35% of patients achieve this metric.

STUDY DESIGN

The interdisciplinary team used quality improvement methods to standardize processes and implement a gastroenterology-managed virtual surveillance clinic. The intervention clinic was implemented in August 2014. Veterans who underwent resection for stage I to III CRC at a single VA facility from January 2010 to December 2017 were included, with those undergoing resection between January 2010 and July 2014 considered pre-intervention and those undergoing resection between August 2014 and December 2017 considered post-intervention. The primary endpoint was the proportion of eligible patients for whom endoscopy was completed within 1 year of resection. Secondary outcomes were the proportion of patients who completed endoscopy within 18 months of resection or at any time post-resection and time to surveillance endoscopy.

RESULTS

A total of 186 patients underwent resection for stage I to III CRC from 2010 to 2017; of these, 160 (86%) were eligible for endoscopy at 1-year post-resection (98 pre-intervention and 62 post-intervention). In the pre-intervention period, 30 of 98 patients (30.6%) underwent surveillance endoscopy within 1 year vs 31 of 62 (50.0%) post-intervention (p = 0.031). When evaluated at 18 months after resection, 56 of 98 patients (57.1%) in the pre-intervention group vs 52 of 62 (83.9%) in the post-intervention group underwent surveillance endoscopy (p = 0.001). Median time from resection to endoscopy decreased during the study period, from 1.19 years pre-intervention (interquartile range 0.93 to 1.74 years) to 1.0 years post-intervention (interquartile range 0.93 to 1.09 years) (p = 0.006).

CONCLUSIONS

Implementation of a virtual surveillance clinic with standardized processes was associated with increased guideline-concordant endoscopic surveillance after CRC resection.

Improved quality of colon cancer surveillance after implementation of a personalized surveillance schedule

BACKGROUND

Early detection of recurrence through surveillance after curative surgery for primary colon cancer is recommended. We previously reported inadequate quality of surveillance among patients operated for colon cancer. These poor results led to the introduction of a personalized surveillance schedule. This study reassesses the quality of surveillance after the introduction of the personalized schedule.

PATIENTS AND METHODS

A total of 93 patients undergoing curative surgery for colon cancer between January 2009 and December 2014 (prospective data registration) were included in this retrospective single-center cohort study. Written informed consent was given by all patients. Compliance with surveillance was compared with national guidelines, as well as with the previous results and analyzed depending on where surveillance was conducted (general practitioner or outpatient clinic).

RESULTS

Adherence to surveillance was higher when performed by oncologists compared to general practitioners with an odds ratio (OR), 6.03 (95%CI: 3.41-10.67, P = .001). Compared with the previous study, adherence to surveillance was significantly higher in the later cohort with an OR = 4.55 (95%CI: 2.50-8.33, P < 0.001).

CONCLUSION

This study demonstrates that the implementation of a personalized surveillance schedule improves adherence to recommendations and that awareness can be increased with this simple measure.

Evidence-based follow-up in colorectal cancer—quo vadis?

Colorectal cancer is the third most common and the third most lethal cancer disease in the western world. As most patients undergo treatment with curative intent at initial diagnosis, postoperative surveillance protocols have been established with the primary aim to detect possible disease recurrence in an early resectable stage. Various international guidelines recommend an intensive surveillance protocol over a 5-year time period. These guidelines are based on the reported significant benefit regarding overall patient survival, and on the observation that 90% of recurrences occur within the first 5 years following resection. Surveillance protocols include regular clinical examinations, measurement of the carcinoembryonic antigen, computed tomography scans and regular endoscopies. While there is plenty of evidence regarding the scheduling of endoscopies, the frequency of carcinoembryonic antigen measurements and computed tomography scans has been ever since under debate. The benefit of intensive compared to low frequency surveillance protocols regarding disease-specific survival has never been shown. Moreover, recent meta-analyses and randomized controlled trials challenge current guidelines. Intensive carcinoembryonic antigen assessment and computed tomography scan follow-up protocols seem to fail in generating better overall and disease-specific survival in colorectal cancer patients compared to less intensive surveillance strategies. This change over the last few decades parallels the treatment evolution of colorectal cancer from a primarily surgical to a multidisciplinary task. Instead of advocating a reduction of the follow-up intensity, these findings should stimulate the colorectal oncology field to move from a one-fits-all to a patient-centered surveillance.