Recurrence and cancer-specific death after adjuvant chemotherapy for Stage III colon cancer

A systematic review of population-based studies on metachronous metastases of colorectal cancer

BACKGROUND

The occurrence of metachronous metastases (MM) of colorectal (CRC), colon (CC), and rectal (RC) cancer of population-based studies has not been compiled in a systematic review previously.

METHODS

MEDLINE, Embase, and Cochrane Library were searched for primary studies of any design from inception until January 2021 and updated in August 2023 (CRD42021261648). The PRISMA guidelines were adopted, and the Newcastle-Ottawa Quality Assessment Scale used for risk of bias assessment. Outcomes on overall and organ-specific MM were extracted. A narrative analysis followed.

RESULTS

Out of 2143 unique hits, 162 publications were read in full-text and 37 population-based cohort studies published in 1981-2022 were included. Ten studies adopted time-dependent analyses; eight were registry-based and seven had a low risk of bias. Three studies reported 5-year recurrence rate of MM overall of stages I-III; for CRC, it was 20.5%, for CC, it was 18% and 25.6%, and for RC, it was 23%. Four studies reported 5-year recurrence rate of organ-specific MM of stages I-III-for CRC, it was 2.2% and 5.5% for peritoneal metastases and 5.8% for lung metastases and for CC 4.5% for peritoneal metastases. Twenty-seven studies reported proportions of patients diagnosed with MM, but data on the length of follow-up was incomplete and varied widely. Proportions of patients with CRC stages I-III that developed MM overall was 14.4%-26.1% in 10 studies. In relation to the enrollment period, a downward trend may be discernible.

CONCLUSION

Studies adopting a more appropriate analysis were highly heterogeneous, whereas uncertain data of partly inadequate studies may indicate that MM are overall declining.

Are Metastatic Central Lymph Nodes (D3 volume) in right-sided Colon Cancer a Sign of Systemic Disease? A sub-group Analysis of an Ongoing Multicenter Trial

OBJECTIVE

Assess outcomes of patients with right-sided colon cancer with metastases in the D3 volume after personalized surgery.

BACKGROUND

Patients with central lymph node metastasis (D3-PNG) are considered to have a systemic disease with a poor prognosis. A 3-dimensional definition of the dissection volume allows the removal of all central nodes.

MATERIALS AND METHODS

D3-PNG includes consecutive patients from an ongoing clinical trial. Patients were stratified into residual disease negative (D3-RDN) and residual disease positive (D3-RDP) groups. D3-RDN was further stratified into 4 periods to identify a learning curve. A personalized D3 volume (defined through arterial origins and venous confluences) was removed " en bloc" through medial-to-lateral dissection, and the D3 volume of the specimen was analyzed separately.

RESULTS

D3-PNG contained 42 (26 females, 63.1 SD 9.9 y) patients, D3-RDN:29 (17 females, 63.4 SD 10.1 y), and D3-RDP:13 (9 females, 62.2 SD 9.7 y). The mean overall survival (OS) days were D3-PNG:1230, D3-RDN:1610, and D3-RDP:460. The mean disease-free survival (DFS) was D3-PNG:1023, D3-RDN:1461, and D3-RDP:74 days. The probability of OS/DFS were D3-PNG:52.1%/50.2%, D3-RDN:72.9%/73.1%, D3-RDP: 7.7%/0%. There is a significant change in OS/DFS in the D3-RDN from 2011-2013 to 2020-2022 (both P =0.046) and from 2014-2016 to 2020-2022 ( P =0.028 and P =0.005, respectively).

CONCLUSION

Our results indicate that surgery can achieve survival in most patients with central lymph node metastases by removing a personalized and anatomically defined D3 volume. The extent of mesenterectomy and the quality of surgery are paramount since a learning curve has demonstrated significantly improved survival over time despite the low number of patients. These results imply a place for the centralization of this patient group where feasible.

The use of adjuvant chemotherapy is not associated with recurrence or cancer-specific death following curative resection for stage III rectal cancer: a competing risks analysis

BACKGROUND

The role of adjuvant chemotherapy (AC) in stage III rectal cancer (RC) has been argued based on evidence from its use in colon cancer. Previous trials have analysed disease-free and overall survivals as endpoints, rather than disease recurrence. This study compares the competing risks incidences of recurrence and cancer-specific death between patients who did and did not receive AC for stage III RC.

METHODS

Consecutive patients who underwent a potentially curative resection for stage III RC (1995-2019) at Concord Hospital, Sydney, Australia, were studied. AC was considered following multidisciplinary discussion. Primary outcome measures were the competing risks incidences of disease recurrence and cancer-specific death. Associations between these outcomes and use of AC (and other variables) were tested by regression modelling.

RESULTS

Some 338 patients (213 male, mean age 64.4 years [SD12.7]) were included. Of these, 208 received AC. The use of AC was associated with resection year (adjusted OR [aOR] 1.74, 95%CI 1.27-2.38); age ≥75 years (aOR0.04, 95%CI 0.02-0.12); peripheral vascular disease (aOR0.08, 95%CI 0.01-0.74); and postoperative abdomino-pelvic abscess (aOR0.23, 95%CI 0.07-0.81). One hundred fifty-seven patients (46.5%) were diagnosed with recurrence; death due to RC occurred in 119 (35.2%). After adjustment for the competing risk of non-cancer death, neither recurrence nor RC-specific death was associated with AC (HR0.97, 95%CI 0.70-1.33 and HR0.72, 95%CI 0.50-1.03, respectively).

CONCLUSION

This study found no significant difference in either recurrence or cancer-specific death between patients who did and did not receive AC following curative resection for stage III RC.

Safety and efficacy of autologous cell vaccines in solid tumors: a systematic review and meta-analysis of randomized control trials

We conducted a systematic review and meta-analysis of randomized control trials to formally assess the safety and efficacy of autologous whole cell vaccines as immunotherapies for solid tumors. Our primary safety outcome was number, and grade of adverse events. Our primary efficacy outcome was clinical responses. Secondary outcomes included survival metrics and correlative immune assays. We searched MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials for studies published between 1946 and August 2020 using any autologous whole cell product in the treatment of any solid tumor. The Cochrane Randomized Controlled Trial risk of bias tool was used to assess risk of bias. Eighteen manuscripts were identified with a total of 714 patients enrolled in control and 808 in vaccine arms. In 698 patients receiving at least one dose of vaccine, treatment was well tolerated with a total of 5 grade III or higher adverse events. Clinical response was reported in a minority (n = 2, 14%) of studies. Autologous cell vaccines were associated with improved overall (HR 1.28, 95% CI 1.01-1.63) and disease-free survival (HR 1.33, 95% CI 1.05-1.67) over thirteen and ten trials respectively. Where reported, immune assays correlated well with clinical outcomes. Our results suggest that autologous whole cell vaccination is safe and efficacious in increasing survival in patients undergoing treatment for solid tumors.Registration: PROSPERO CRD42019140187.

Assessment of adjuvant chemotherapy benefits after complete mesocolic excision in patients with colon cancer: Reanalysis of data from the ESCME trial

AIM

The benefits of adjuvant chemotherapy (AC) in colon cancer after complete mesocolic excision (CME) have not been evaluated sufficiently. We reanalysed the ESCME trial data to investigate the survival benefits and establish AC stratified indications.

METHODS

The data of Stage II and III colon cancer patients who received CME in the ESCME trial were reanalysed. Patients were divided into AC and non-AC (NAC) groups. The primary outcomes measured were differences in 5-year cancer-specific survival and disease-free survival (DFS) between the groups.

RESULTS

Of the 206 patients enrolled in the study, 125 patients (AC, 49; NAC, 76) had Stage II cancer and 111 (AC, 86; NAC, 25) had Stage III cancer. There were no significant differences in the adjusted 5-year cancer-specific survival and DFS between the AC and NAC groups. Poor differentiation (hazard ratio [HR] 2.947; 95% CI 1.218-7.131) and RAS mutation (HR 3.140; 95% CI 1.363-7.234) affected the 5-year DFS significantly in multivariate Cox regression analysis for Stage II and III cancer, respectively. In subgroup analysis, AC significantly improved 5-year DFS (HR 0.369; 95% CI 0.140-0.978) for Stage III cancer with lymphovascular/perineural invasion compared to NAC.

CONCLUSION

The current indication and benefits of AC for colon cancer patients after CME should be re-evaluated. AC is more appropriate for Stage III cancer with lymphovascular/perineural invasion.

Finding Waldo: The Evolving Paradigm of Circulating Tumor DNA (ctDNA)—Guided Minimal Residual Disease (MRD) Assessment in Colorectal Cancer (CRC)

Simple Summary

After the surgical removal of colorectal cancer (CRC), residual cancer cells undetectable by standard blood tests and imaging studies are responsible for cancer recurrence. Currently, chemotherapy is often administered after surgery to eradicate residual cancer cells, a decision guided by clinical and pathologic criteria, which are imprecise. Circulating tumor DNA (ctDNA) consists of DNA fragments in the bloodstream derived from cancer cells, and the presence of ctDNA likely indicates the presence of residual cancer cells. The current article discusses how ctDNA technology can help guide treatment in patients with CRC after curative surgery.

Abstract

Circulating tumor DNA (ctDNA), the tumor-derived cell-free DNA fragments in the bloodstream carrying tumor-specific genetic and epigenetic alterations, represents an emerging novel tool for minimal residual disease (MRD) assessment in patients with resected colorectal cancer (CRC). For many decades, precise risk-stratification following curative-intent colorectal surgery has remained an enduring challenge. The current risk stratification strategy relies on clinicopathologic characteristics of the tumors that lacks precision and results in over-and undertreatment in a significant proportion of patients. Consequently, a biomarker that can reliably identify patients harboring MRD would be of critical importance in refining patient selection for adjuvant therapy. Several prospective cohort studies have provided compelling data suggesting that ctDNA could be a robust biomarker for MRD that outperforms all existing clinicopathologic criteria. Numerous clinical trials are currently underway to validate the ctDNA-guided MRD assessment and adjuvant treatment strategies. Once validated, the ctDNA technology will likely transform the adjuvant therapy paradigm of colorectal cancer, supporting ctDNA-guided treatment escalation and de-escalation. The current article presents a comprehensive overview of the published studies supporting the utility of ctDNA for MRD assessment in patients with CRC. We also discuss ongoing ctDNA-guided adjuvant clinical trials that will likely shape future adjuvant therapy strategies for patients with CRC.

Comparing 5-Year Survival Rates Before and After Re-stratification of Stage I-III Right-Sided Colon Cancer Patients by Establishing the Presence/Absence of Occult Tumor Cells and Lymph Node Metastases in the Different Levels of Surgical Dissection

BACKGROUND

To establish the impact of re-stratification on the outcomes of patients (stage I-III right-sided colon cancer) based on the presence/absence of occult tumor cells (OTC) and/or metastatic lymph nodes in the different levels of surgical dissection.

METHODS

Consecutive patients were drawn from a multicenter prospective trial. After surgery, the surgical specimen was divided into the D1/D2 and D3 volumes before being further analyzed separately. All lymph nodes were examined with cytokeratin CAM 5.2 immunohistochemically. Lymph nodes containing metastases and OTC (micrometastases; isolated tumor cells) were identified. Re-stratification was as follows: RS1, stages I/II, no OTC in D1/D2 and D3 volumes; RS2, stages I/II, OTC in D1/D2 and/or D3; RS3, stage III, lymph node metastases in D1/D2, with/without OTC in D3; RS4, stage III, lymph node metastases in D3, with/without OTC in D3.

RESULTS

Eighty-seven patients (39 men, 68.4 + 9.9 years) were included. The standard stratified (SS) group contained the following: stages I/II (SS1) 57 patients; stage III (SS2) 30 patients. Re-stratified (RS) contained RS1 (38), RS2 (19), RS3 (24), and RS4 (6) patients. Lymph node ratio (OTC) RS2: 0.157 D1/D2; 0.035 D3 and 0.092 complete specimens. Lymph node ratio RS3: 0.113 D1/D2; complete specimen 0.056. Overall survival and disease-free survival were p = 0.875 and p = 0.049 for SS and p = 0.144 and p = 0.001 for RS groups, respectively.

CONCLUSION

This re-stratification identifies a patient group with poor prognosis (RS4). Removing this group from SS2 eliminates all the differences in survival between RS2 and RS3 groups. The level of dissection of the affected nodes may have an impact on survival.

CLINICAL TRIAL

"Safe Radical D3 Right Hemicolectomy for Cancer through Preoperative Biphasic Multi-Detector Computed Tomography (MDCT) Angiography" registered at http://clinicaltrials.gov/ct2/show/NCT01351714.

Chitosan-Decorated PLGA-NPs Loaded with Tannic Acid/Vitamin E Mitigate Colon Cancer via the NF-κB/β-Cat/EMT Pathway

Colon cancer is the second highest contributor of cancer-related deaths throughout the world. Treatment strategies with tannic acid and vitamin E are envisaged as desirable and safe owing to their robust antioxidative and anti-inflammatory potential. In the present report, these bioactives have been nanoencapsulated in poly(d,l-lactide-co-glycolic acid) (PLGA) formulations for maintaining sustained release and ensuring enhanced bioavailability. Capping of nanoparticles (NPs) with chitosan was done for enhanced anticancer efficacy and tumor targeting. CS-PLGA-TA-E, administered intraperitoneally, significantly inhibited tumor number and tumor volume and normalized colon histology in the colon cancer. Tissue distribution studies showed that TA/E content from CS-PLGA-TA-E was present in a higher concentration in the tumor tissue than the concentration of TA/E content from PLGA-TA-E or free TA or free E. Also, the TA/E content from all of the treatment groups showed its highest concentration in the tumor compared to other organs. Antioxidant enzymes and proinflammatory cytokines (TNF-α, IL-1β, IL-6) were inhibited by CS-PLGA-TA-E. CS-PLGA-TA-E inhibited markers for tumor growth (EGFR-PI3K-AKT), inflammation (NF-κB/Stat3), β-catenin signaling (β-catenin, c-myc, cyclin D1), EMT (E-cadherin, N-cadherin, vimentin), and apoptosis (Bcl-2) in a significantly greater way as compared with PLGA-TA-E, TA, or E. CS-PLGA-TA-E NPs can be considered promising anticancer drugs for colon cancer.

Recurrence and colon cancer-specific death in patients with large bowel obstruction requiring urgent operation: a competing risks analysis

AIM

Clinical presentation with large bowel obstruction has been proposed as a predictor of poor long-term oncological outcomes after resection for colorectal cancer. This study examines the association between obstruction and recurrence and cancer-specific death after resection for colon cancer.

METHOD

Consecutive patients who underwent resection for colon cancer between 1995 and 2014 were drawn from a prospectively recorded hospital database with all surviving patients followed for at least 5 years. The outcomes of tumour recurrence and colon cancer-specific death were assessed by competing risks multivariable techniques with adjustment for potential clinical and pathological confounding variables.

RESULTS

Recurrence occurred in 271 of 1485 patients who had a potentially curative resection. In bivariate analysis, obstruction was significantly associated with recurrence [hazard ratio (HR) 2.23, CI 1.52-3.26, p < 0.001] but this association became nonsignificant after adjustment for confounders (HR 1.53, CI 0.95-2.46, p = 0.080). Colon cancer-specific death occurred in 238 of 295 patients who had a noncurative resection. Obstruction was not significantly associated with cancer-specific death (HR 1.02, CI 0.72-1.45, p = 0.903). In patients who had a noncurative resection, the competing risks incidence of colon cancer-specific death was not significantly greater in obstructed than in unobstructed patients (HR 1.02, CI 0.72-1.45, p = 0.903).

CONCLUSION

Whilst the immediate clinical challenge of an individual patient presenting with large bowel obstruction must be addressed by the surgeon, the patient's long-term oncological outcomes are unrelated to obstruction per se.

Colorectal cancer databases and registries in Australia: what data is available?

BACKGROUND

There are multiple data sources relating to colorectal cancer (CRC) nationwide. Prospective clinical cancer databases, population-based registries and linked administrative data are powerful tools in clinical outcomes research and provide real-world perspective on cancer treatments. This study aims to review the different Australian data sources for CRC from the perspective of conducting comparative research studies using a PICO (patient, intervention, comparison, outcome) framework.

METHODS

Data dictionaries from the different data sources were evaluated for the types of exposure and outcome variables contained to highlight their differing research utility.

RESULTS

State or territory-based cancer registries contain limited histology, cancer staging and treatment detail. They enable investigation of population-level patterns in overall survival (OS) of cancer patients with different demographics. Prospective clinical cancer databases contain more detail, especially surgical. Their strength is in auditing short-term surgical outcomes. They vary in the amount of data collected for other cancer treatments and completion of follow up data. Linked administrative databases have broad population coverage but less surgical detail. They provide population-level data on treatment patterns, short-term outcome measures and OS, as well as long-term surgical outcomes such as identifying patients who did not undergo stoma reversal. These databases cannot assess disease-free survival.

CONCLUSION

Of the various CRC data sources within Australia, linked administrative databases have the potential to provide the widest population coverage combined with the broadest range of exposures and outcomes, and arguably the most research utility.

Impact of Andrographolide and Melatonin Combinatorial Drug Therapy on Metastatic Colon Cancer Cells and Organoids

Background:

The death rate (the number of deaths per 100 000 people per year) of colorectal cancer (CRC) has been dropping since 1980 due to increased screening, lifestyle-related risk factors, and improved treatment options; however, CRC is the third leading cause of cancer-related deaths in men and women in the United States. Therefore, successful therapy for CRC is an unmet clinical need. This study aimed to investigate the impacts of andrographolide (AGP) and melatonin (MLT) on CRC and the underlying mechanism.

Methods:

To investigate AGP and MLT anticancer effects, a series of metastatic colon cancer cell lines (T84, Colo 205, HT-29, and DLD-1) were selected. In addition, a metastatic patient-derived organoid model (PDOD) was used to monitor the anticancer effects of AGP and MLT. A series of bioassays including 3D organoid cell culture, MTT, colony formation, western blotting, immunofluorescence, and quantitative polymerase chain reaction (qPCR) were performed.

Results:

The dual therapy significantly promotes CRC cell death, as compared with the normal cells. It also limits CRC colony formation and disrupts the PDOD membrane integrity along with decreased Ki-67 expression. A significantly higher cleaved caspase-3 and the endoplasmic reticulum (ER) stress proteins, IRE-1 and ATF-6 expression, by 48 hours were found. This combinatorial treatment increased reactive oxygen species (ROS) levels. Apoptosis signaling molecules BAX, XBP-1, and CHOP were significantly increased as determined by qPCR.

Conclusions:

These findings indicated that AGP and MLT associated ER stress-mediated apoptotic metastatic colorectal cancer (mCRC) cell death through the IRE-1/XBP-1/CHOP signaling pathway. This novel combination could be a potential therapeutic strategy for mCRC cells.

Endoscopic Resection Before Surgery Does Not Affect the Recurrence Rate in Patients With High-Risk T1 Colorectal Cancer

INTRODUCTION

Patients with high-risk T1 colorectal cancer (CRC) after endoscopic resection (ER) should undergo surgery in view of the risk of lymph node metastasis. Although additional surgery can potentially prevent recurrence, there is a paucity of data and longitudinal studies exploring this potential. Hence, this study aimed to evaluate the prolonged influence of ER before additional surgery on recurrence in T1 CRC.

METHODS

Between January 2004 and October 2015, 162 patients who underwent secondary surgery (SS) after ER ([ER + SS] group) and 392 consecutive patients with T1 CRC who underwent primary surgery at our institution were retrospectively analyzed. Recurrence was analyzed in these 2 groups. High-risk CRC patients were histologically defined according to the Japanese Society for Cancer of the Colon and Rectum guidelines (2016) for the treatment of CRC. Data were analyzed based on clinical and histological features, including lymph node metastasis, and the number of lymph nodes evaluated.

RESULTS

The recurrence rate was comparable between the ER + SS and primary surgery groups, with no significant difference (P = 0.625, log-rank test). There was no significant difference in the recurrence in patients receiving adjuvant chemotherapy in both groups (7.4% vs 10.4%, P = 0.27). The difference in the mean number of lymph nodes dissected between both groups was also not significant (24.3 vs 25.3, P = 0.43).

DISCUSSION

There was no significant difference in recurrence rates between patients undergoing ER before surgery and those undergoing primary surgery for high-risk T1 CRC. Hence, ER may be acceptable for high-risk T1 CRC.

Pluripotent Stem Cells: Cancer Study, Therapy, and Vaccination

INTRODUCTION

Pluripotent stem cells (PSCs) are promising tools for modern regenerative medicine applications because of their stemness properties, which include unlimited self-renewal and the ability to differentiate into all cell types in the body. Evidence suggests that a rare population of cells within a tumor, termed cancer stem cells (CSCs), exhibit stemness and phenotypic plasticity properties that are primarily responsible for resistance to chemotherapy, radiotherapy, metastasis, cancer development, and tumor relapse. Different therapeutic approaches that target CSCs have been developed for tumor eradication.

RESULTS AND DISCUSSION

In this review, we first provide an overview of different viewpoints about the origin of CSCs. Particular attention has been paid to views believe that CSCs are probably appeared through dysregulation of very small embryonic-like stem cells (VSELs) which reside in various tissues as the main candidate for tissue-specific stem cells. The expression of pluripotency markers in these two types of cells can strengthen the validity of this theory. In this regard, we discuss the common properties of CSCs and PSCs, and highlight the potential of PSCs in cancer studies, therapeutic applications, as well as educating the immune system against CSCs.

CONCLUSION

In conclusion, the resemblance of CSCs to PSCs can provide an appropriate source of CSC-specific antigens through cultivation of PSCs which brings to light promising ideas for prophylactic and therapeutic cancer vaccine development.

Quantitative analysis of CDX2 protein expression improves its clinical utility as a prognostic biomarker in stage II and III colon cancer

AIM

Better stratification of patients with stage II and stage III colon cancer for risk of recurrence is urgently needed. The present study aimed to validate the prognostic value of CDX2 protein expression in colon cancer tissue by routine immunohistochemistry and to evaluate its performance in a head-to-head comparison with tandem mass spectrometry-based proteomics.

PATIENT AND METHODS

CDX2 protein expression was evaluated in 386 stage II and III primary colon cancers by immunohistochemical staining of tissue microarrays and by liquid chromatography with tandem mass spectrometry (LC-MS/MS) analysis using formalin-fixed paraffin-embedded tissue sections of a matched subset of 23 recurrent and 23 non-recurrent colon cancers. Association between CDX2 expression and disease-specific survival (DSS) was investigated.

RESULTS

Low levels of CDX2 protein expression in stage II and III colon cancer as determined by immunohistochemistry was associated with poor DSS (hazard ratio [HR] = 1.97 (95% confidence interval [CI]: 1.26-3.06); p = 0.002). Based on analysis of a selected sample subset, CDX2 prognostic value was more pronounced when detected by LC-MS/MS (HR = 7.56 (95% CI: 2.49-22.95); p < 0.001) compared to detection by immunohistochemistry (HR = 1.60 (95% CI: 0.61-4.22); p = 0.34).

CONCLUSION

This study validated CDX2 protein expression as a prognostic biomarker in stage II and III colon cancer, conform previous publications. CDX2 prognostic value appeared to be underestimated when detected by routine immunohistochemistry, probably due to the semiquantitative and subjective nature of this methodology. Quantitative analysis of CDX2 substantially improved its clinical utility as a prognostic biomarker. Therefore, development of routinely applicable quantitative assays for CDX2 expression is needed to facilitate its clinical implementation.

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.