Capecitabine versus S-1 as adjuvant chemotherapy for patients with stage III colorectal cancer (JCOG0910): an open-label, non-inferiority, randomised, phase 3, multicentre trial

Accrual and statistical power failure in published adjuvant phase III oncology trials: a comprehensive analysis from 2013 to 2023

BACKGROUND

In a competitive landscape with many ongoing adjuvant randomised controlled trials (RCTs), the prevalence of trials that failed to recruit their targeted sample size and were inadequately powered is unclear. The aims of the study are (i) to determine the percentage of trials with accrual and statistical power failure and (ii) to evaluate their potential impact on the drug development process.

MATERIALS AND METHODS

A systematic review was carried out to identify adjuvant phase III oncology RCTs reported between 2013 and 2023 across all solid tumours. No restrictions were applied regarding the type of intervention or journal of publication. The percentage of trials with accrual failure and power failure was estimated as well as their association with the efficacy endpoints. Logistic regression models were used to estimate the odds ratio (OR) and its 95% confidence interval (CI).

RESULTS

A total of 282 RCTs met the inclusion criteria with a median sample size of 661 patients and a median accrual period of 4.3 years. Most of these studies were superiority trials (83.0%). Accrual failure was observed in 22.0% of the studies, finishing recruitment without achieving the targeted sample size. Overall, 39.7% of the studies experienced power failure, having less power than specified in the protocol at the date of the read-out. Among superiority RCTs evaluating intermediate survival endpoints, only 31.1% presented statistically significant results. Trials with power failure were less likely to present statistically significant results (37.9% versus 21.9%, P = 0.04). The association was consistent across all cancer types. In the subset of non-inferiority trials, 35.0% formally demonstrated non-inferiority of the experimental arm.

CONCLUSIONS

Nearly 40% of adjuvant phase III RCTs experienced power failure, and the reduction in power significantly impacted the final study results. There is a need for procedural refinements in the design and implementation of future adjuvant RCTs to mitigate these fallacies.

Localized colorectal cancer database integrating 4 randomized controlled trials; (JCOG2310A)

Although phase III randomized controlled trials (RCTs) represent the most robust statistical approach for answering clinical questions, they require massive expenditures in terms of time, labor, and funding. Ancillary and supplementary analyses using RCTs are sometimes conducted as alternative approaches to answering clinical questions, but the available integrated databases of RCTs are limited. In this background, the Colorectal Cancer Study Group (CCSG) of the Japan Clinical Oncology Group (JCOG) established a database of ancillary studies integrating four phase III RCTs (JCOG0212, JCOG0404, JCOG0910 and JCOG1006) conducted by the CCSG to investigate specific clinicopathological factors in pStage II/III colorectal cancer (JCOG2310A). This database will be updated by adding another clinical trial data and accelerating several analyses that are clinically relevant in the management of localized colorectal cancer. This study describes the details of this database and planned and ongoing analyses as an initiative of JCOG cOlorectal Young investigators (JOY).

Prognostic Relevance of Primary Tumor Sidedness in Early-stage Colorectal Cancer: An Integrated Analysis of 4 Randomized Controlled Trials (JCOG2003A)

OBJECTIVE

The aim of this study was to determine the genuine prognostic relevance of primary tumor sidedness (PTS) in patients with early-stage colorectal cancer (CRC).

BACKGROUND

The prognostic relevance of PTS in early-stage CRC remains a topic of debate. Several large epidemiological studies investigated survival only and did not consider the risk of recurrence so far.

METHODS

Patients with stage II/III adenocarcinoma of the colon and upper rectum from 4 randomized controlled trials were analyzed. Survival outcomes were compared according to the tumor location: right-sided (cecum to transverse colon) or left-sided (descending colon to upper rectum).

RESULTS

A total of 4113 patients were divided into a right-sided group (N=1349) and a left-sided group (N=2764). Relapse-free survival after primary surgery was not associated with PTS in all patients and each stage [hazard ratio (HR) adjusted =1.024 (95% CI: 0.886-1.183) in all patients; 1.327 (0.852-2.067) in stage II; and 0.990 (0.850-1.154) in stage III]. Also, overall survival after primary surgery was not associated with PTS in all patients and each stage [HR adjusted =0.879 (95% CI: 0.726-1.064) in all patients; 1.517 (0.738-3.115) in stage II; and 0.840 (0.689-1.024) in stage III]. In total, 795 patients (right-sided, N=257; left-sided, N=538) developed recurrence after primary surgery. PTS was significantly associated with overall survival after recurrence (HR adjusted =0.773, 95% CI: 0.627-0.954).

CONCLUSIONS

PTS had no impact on the risk of recurrence for stage II/III CRC. Treatment stratification based on PTS is unnecessary for early-stage CRC.

DYRK2 promotes chemosensitivity via p53-mediated apoptosis after DNA damage in colorectal cancer

Dual-specificity tyrosine-regulated kinase 2 (DYRK2) is a protein kinase that phosphorylates p53-Ser46 and induces apoptosis in response to DNA damage. However, the relationship between DYRK2 expression and chemosensitivity after DNA damage in colorectal cancer has not been well investigated. The aim of the present study was to examine whether DYRK2 could be a novel marker for predicting chemosensitivity after 5-fluorouracil- and oxaliplatin-induced DNA damage in colorectal cancer. Here we showed that DYRK2 knockout decreased the chemosensitivity to 5-fluorouracil and oxaliplatin in p53 wild-type colorectal cancer cells, whereas the chemosensitivity remained unchanged in p53-deficient/mutated colorectal cancer cells. In addition, no significant differences in chemosensitivity to 5-fluorouracil and oxaliplatin between scramble and siDYRK2 p53(-/-) colorectal cancer cells were observed. Conversely, the combination of adenovirus-mediated overexpression of DYRK2 with 5-fluorouracil or oxaliplatin enhanced apoptosis and chemosensitivity through p53-Ser46 phosphorylation in p53 wild-type colorectal cancer cells. Furthermore, DYRK2 knockout decreased chemosensitivity to 5-fluorouracil and oxaliplatin in p53 wild-type xenograft mouse models. Taken together, these findings demonstrated that DYRK2 expression was associated with chemosensitivity to 5-fluorouracil and oxaliplatin in p53 wild-type colorectal cancer, suggesting the importance of evaluating the p53 status and DYRK2 expression as a novel marker in therapeutic strategies for colorectal cancer.

Adjuvant and neoadjuvant chemotherapy for biliary tract cancer: a review of randomized controlled trials

The first randomized controlled trial of adjuvant chemotherapy for biliary tract cancer was reported in 2002. Since then, studies have continued, with efficacy reported for capecitabine in 2018 and S-1 in 2023. Oral fluoropyrimidines have become established as the standard of care. This article reviews the evidence from the randomized controlled trials reported to date and those that are ongoing or from which results have not yet been reported.

Exploratory randomized phase II trial for optimizing treatment dosage and duration of adjuvant S-1 plus oxaliplatin in patients with stage III colon cancer: YCOG1402 (SOAP trial)

Introduction

Conventionally, the recommended duration of adjuvant chemotherapy of colon cancer had been 6 months. The IDEA Collaboration suggested that shortening capecitabin and oxaliplatin (CAPOX) adjuvant chemotherapy may be possible. S-1 and oxaliplatin (SOX) treatment is standard treatment in metastatic colorectal cancer in Japan. The aim of this study was to optimize treatment dosage and duration of adjuvant SOX in stage III colon cancer.

Methods

This trial was as open-label multi-center randomized phase II study. Patients with stage III colon cancer were randomly assigned to 3 months or 6 months of adjuvant SOX treatment in different doses: 130 mg/m2 (3 months) or 100 mg/m2 (6 months) of oxaliplatin. The primary endpoint was 3-year disease-free survival (DFS) and the null hypothesis for the primary endpoint was that the 3-year DFS was ≤72% in each arm and was tested with a one-sided significance level of 10%.

Results

Eighty-two patients were assigned to the 6 months arm and 81 to the 3 months arm. The 3-year DFS was 75.0% (80% CI 67.95-80.72, p = 0.282) in the 6 months arm and 76.9% (80% CI 70.1-82.38, p = 0.171) in the 3 months arm. Treatment completion rate and relative dose intensity (RDI) were higher in 3 months than 6 months arm. The adverse events (AE) were similar in both arms.

Conclusions

The 3-year DFS was not significantly superior to null hypothesis in both 3 months and 6 months arms for the stage III colon cancer. Primary endpoint was not achieved. The SOX regimen was not feasible in long-term outcomes.

Genomic landscape and its prognostic significance in stage III colorectal cancer: JCOG1506A1, an ancillary of JCOG0910

Large-scale genomic sequencing of colorectal cancers has been reported mainly for Western populations. Differences by stage and ethnicity in the genomic landscape and their prognostic impact remain poorly understood. We investigated 534 Japanese stage III colorectal cancer samples from the Phase III trial, JCOG0910. Targeted-capture sequencing of 171 potentially colorectal cancer-associated genes was performed, and somatic single-nucleotide variants and insertion-deletions were determined. Hypermutated tumors were defined as tumors with MSIsensor score >7 and ultra-mutated tumors with POLE mutations. Genes with alterations associated with relapse-free survival were analyzed using multivariable Cox regression models. In all patients (184 right-sided, 350 left-sided), mutation frequencies were TP53, 75.3%; APC, 75.1%; KRAS, 43.6%; PIK3CA, 19.7%; FBXW7, 18.5%; SOX9, 11.8%; COL6A3, 8.2%; NOTCH3, 4.5%; NRAS, 4.1%; and RNF43, 3.7%. Thirty-one tumors were hypermutated (5.8%; 14.1% right-sided, 1.4% left-sided). Modest associations were observed: poorer relapse-free survival was seen with mutant KRAS (hazard ratio 1.66; p = 0.011) and mutant RNF43 (2.17; p = 0.055), whereas better relapse-free survival was seen with mutant COL6A3 (0.35; p = 0.040) and mutant NOTCH3 (0.18; p = 0.093). Relapse-free survival tended to be better for hypermutated tumors (0.53; p = 0.229). In conclusion, the overall spectrum of mutations in our Japanese stage III colorectal cancer cohort was similar to that in Western populations, but the frequencies of mutation for TP53, SOX9, and FBXW7 were higher, and the proportion of hypermutated tumors was lower. Multiple gene mutations appeared to impact relapse-free survival, suggesting that tumor genomic profiling can support precision medicine for colorectal cancer.

Chronomodulated Administration of Chemotherapy in Advanced Colorectal Cancer: A Systematic Review and Meta-Analysis

In this systematic review, the efficacy and safety of chronomodulated chemotherapy, defined as the delivery of chemotherapy timed according to the human circadian rhythm, were assessed and compared to continuous infusion chemotherapy for patients with advanced colorectal cancer. Electronic English-language studies published until October 2020 were searched. Randomised controlled trials (RCTs) comparing chronomodulated chemotherapy with non-chronomodulated (conventional) chemotherapy for the management of advanced colorectal cancer were included. The main outcomes were the objective response rate (ORR) and system-specific and overall toxicity related to chemotherapy. Electronic databases including Ovid Medline, Ovid Embase, Cochrane Central Register of Controlled Trials and the Cochrane Database of Systematic Review were searched. In total, seven RCTs including 1,137 patients were analysed. Males represented 684 (60%) of the study population. The median age was 60.5 (range = 47.2-64) years. There was no significant difference between chronomodulated and conventional chemotherapy in ORR (risk ratio (RR) = 1.15; 95% confidence interval (CI) = 0.87-1.53). Similarly, there was no significant difference in gastrointestinal toxicity under the random effect model (RR = 1.02; 95% CI = 0.68-1.51). No significant difference was found regarding neurological and skin toxicities (RR = 0.64, 95% CI = 0.32-1.270 and RR = 2.11, 95% CI = 0.33-13.32, respectively). However, patients who received chronomodulated chemotherapy had less haematological toxicity (RR = 0.36, 95% CI = 0.27-0.48). In conclusion, there was no overall difference in ORR or haematologic toxicity between chronomodulated and non-chronomodulated chemotherapy used for patients with advanced colorectal cancer. Chronomodulated chemotherapy can be considered in patients at high risk of haematological toxicities.

Real impact of oxaliplatin in adjuvant chemotherapy for patients with stage III colon cancer based on the Multi-Institutional Registry of Large Bowel Cancer in Japan

Although fluoropyrimidine plus oxaliplatin is the standard of care for stage III colon cancer, fluoropyrimidine alone is also recommended for stage III patients in Japanese and other practice guidelines. We assessed efficacy of adjuvant fluoropyrimidine with or without oxaliplatin across a population of patients with stage III colon cancer in the Multi-Institutional Registry of Large Bowel Cancer in Japan. From the registry, we analyzed 6,834 stage III colorectal cancer patients. Approximately 70% of colorectal cancer patients received some form of chemotherapy. Of these, we analyzed those who received adjuvant chemotherapy between 2008 and 2011. Based on the TNM classification, the 5-year overall survival rates of colon and rectal cancer after the covariate adjustment by regimens of adjuvant chemotherapy were 95.7% with fluoropyrimidines and 90.6% with oxaliplatin-combined therapy at stage IIIA (Stratified log-rank P < 0.001), 86.5% and 80.8% at stage IIIB (P < 0.001), and 72.1% and 70.7% at stage IIIC (P < 0.001), respectively. Oxaliplatin did not enhance efficacy with regard to relapse-free survival as well as overall survival. Adjuvant fluoropyrimidine monotherapy and fluoropyrimidine plus oxaliplatin show comparable efficacy benefits for the treatment of stage III of Japanese colon cancer patients. This supports the use of fluoropyrimidine alone as a standard option for this patient group in Japan.

Cost-effectiveness of 12 months of capecitabine as adjuvant chemotherapy for stage III colon cancer: preplanned cost-effectiveness analysis of the JFMC37-0801 study

OBJECTIVES

We evaluated the cost-effectiveness of a 12-month regimen of oral capecitabine versus a standard 6-month regimen as postoperative adjuvant chemotherapy for stage III colon cancer.

METHODS

We utilized patient-level data from a multi-institutional randomized controlled trial (JFMC37-0801) that investigated prolonged oral fluoropyrimidine monotherapy. The analysis considered three health states: stable disease, post-metastasis, and death. A parametric statistical model with a cure model was used to estimate the survival curve. The analysis was conducted from the Japanese public healthcare payer's perspective, considering only direct medical costs. A lifetime horizon was used, with a discount rate of 2% for both cost and health outcomes. Health outcomes were evaluated in terms of quality-adjusted life-years (QALYs).

RESULTS

The estimated cure rates for colon cancer were 0.726 [95% confidence interval (CI) 0.676-0.776] and 0.694 (95% CI 0.655-0.733) with the 12- and 6-month regimens, respectively; and the estimated 5-year relapse-free survival rates were 74.4% and 69.8%, respectively. The estimated lifetime cost for 12 months of capecitabine was JPY 3.365 million (USD 31,159), compared with JPY 3.376 million (USD 31,262) for 6 months. The estimated QALY were 12.48 and 11.77 for the 12- and 6-month regimens, respectively. Thus, the 12-month capecitabine regimen was dominant. Using a willingness-to-pay threshold of JPY 5 million per QALY, we determined a 97.4% probability that the 12-month capecitabine regimen is more cost-effective than the 6-month regimen.

CONCLUSIONS

Twelve months of capecitabine is the favorable option for postoperative adjuvant chemotherapy for stage III colon cancer from the perspective of cost-effectiveness.

Study protocol of a single-arm phase 2 study evaluating the preventive effect of topical hydrocortisone for capecitabine-induced hand-foot syndrome in colorectal cancer patients receiving adjuvant chemotherapy with capecitabine plus oxaliplatin (T-CRACC study)

BACKGROUNDS

Clinical evidence of the preventive effectiveness of medium-class topical corticosteroids for capecitabine-induced hand foot syndrome (HFS) is limited. Although the pathogenesis and mechanism of HFS are unclear, inflammatory reactions are thought to be involved in HFS development. This study aimed to evaluate the preventive effect of medium-class topical corticosteroids (hydrocortisone butyrate 0.1% topical therapy) for capecitabine-induced HFS in patients with colorectal cancer receiving adjuvant chemotherapy with capecitabine plus oxaliplatin.

METHODS

This is a single-center, single-arm, phase 2 study. Patients with colorectal cancer scheduled to receive adjuvant chemotherapy with capecitabine plus oxaliplatin are enrolled, and topical hydrocortisone butyrate 0.1% is applied prophylactically in addition to standard moisturizing therapy. The primary endpoint is the incidence of grade ≥ 2 HFS within three months. The secondary endpoints are the time to onset of HFS, rates of dose reduction, schedule delay, discontinuation caused by capecitabine-induced HFS, and other adverse events. All adverse events are evaluated by clinical pharmacists and attending physicians.

DISCUSSION

This study is expected to contribute to the establishment of new supportive care for preventing HFS, not only for colorectal cancer patients receiving adjuvant chemotherapy, but also for various cancer patients receiving capecitabine-based chemotherapy.

TRIAL REGISTRATION

This trial was registered in the Japan Registry of Clinical Trials (jRCT) as jRCTs031220002. Registered 5 April 2022, https://jrct.niph.go.jp/search Protocol version V.1.0, 16 February 2022.

The Conventional Technique Versus the No-touch Isolation Technique for Primary Tumor Resection in Patients With Colon Cancer (JCOG1006): A Multicenter, Open-label, Randomized, Phase III Trial

OBJECTIVE

This phase III trial evaluated whether the no touch was superior to the conventional in patients with cT3/T4 colon cancer.

BACKGROUND

No touch involves ligating blood vessels that feed the primary tumor to limit cancer cell spreading. However, previous studies did not confirm the efficacy of the no touch.

METHODS

This open-label, randomized, phase III trial was conducted at 30 Japanese centers. The eligibility criteria were histologically proven colon cancer; clinical classification of T3-4, N0-2, andM0; and patients aged 20 to 80years. Patients were randomized (1:1) to undergo open surgery with conventional or the no touch. Patients with pathological stage III disease received adjuvant capecitabine chemotherapy. The primary endpoint was disease-free survival (DFS) according to the intention-to-treat principle.

RESULTS

Between January 2011 and November 2015, 853 patients were randomized to the conventional group (427 patients) or the no touch group (426 patients). The 3-year DFS were 77.3% [95% confidence interval (CI) 73.1%-81.0%] and 76.2% (95% CI 71.9%-80.0%) in the conventional and no touch groups, respectively. The superiority of no touch was not confirmed: hazard ratio for DFS = 1.029 (95% CI 0.800- 1.324; 1-sided P = 0.59). Operative morbidity was observed in 31 of 427 conventional patients (7%) and 26 of 426 no touch patients (6%). All grade adverse events were similar between the conventional and no touch groups. No in-hospital mortality occurred in either group.

CONCLUSION

The present study failed to confirm the superiority of the no touch.

Managing 5FU Cardiotoxicity in Colorectal Cancer Treatment

Fluorouracil (5FU) is the backbone chemotherapy agent in the treatment of colorectal cancer (CRC). Cardiotoxicity represents an uncommon but serious side effect of treatment with 5FU. Here, we review the current literature on 5FU-cardiotoxicity in the setting of CRC specifically, with a focus on data from the modern era of combination chemotherapy. Despite decades of study, there is little consensus on risk factors and biomarkers for 5FU-cardiotoxicity, nor how patients with CRC should be managed following a cardiotoxicity event. Given the elevated risk of recurrent cardiotoxicity on rechallenge, the use of alternative regimens that do not contain 5FU is a critical aspect of management. Data on the cardiotoxicity risk and efficacy of non-5FU regimens in CRC are therefore reviewed in detail.

Pan-Asian adapted ESMO Clinical Practice Guidelines for the diagnosis treatment and follow-up of patients with localised colon cancer

The most recent version of the European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of localised colon cancer was published in 2020. It was decided by both the ESMO and the Japanese Society of Medical Oncology (JSMO) to convene a special virtual guidelines meeting in March 2021 to adapt the ESMO 2020 guidelines to take into account the ethnic differences associated with the treatment of localised colon cancer in Asian patients. These guidelines represent the consensus opinions reached by experts in the treatment of patients with localised colon cancer representing the oncological societies of Japan (JSMO), China (CSCO), India (ISMPO), Korea (KSMO), Malaysia (MOS), Singapore (SSO) and Taiwan (TOS). The voting was based on scientific evidence and was independent of the current treatment practices and drug availability and reimbursement situations in the different Asian countries.

Selection of Oral Therapeutics in China for the Treatment of Colorectal Cancer

OPINION STATEMENT

Intravenous administration of fluoropyrimidine-based chemotherapy has been the backbone of treatment in colorectal cancer (CRC) for decades. The availability of oral capecitabine has improved the tolerability and simplified combination schedules. In addition to capecitabine, several other oral drugs have proven efficacy, particularly in palliative treatment lines. Clinical guidelines describe several available third-line treatment options for metastatic CRC (mCRC), but few insights are provided to guide the selection and sequence. In this review, we describe the available evidence and most recent data concerning oral drugs with proven efficacy in CRC, including antiangiogenetic tyrosine kinase inhibitors (VEGFR TKIs), inhibitors blocking EGFR/Raf/MEK/ERK signaling pathway and modified fluoropyrimidine, and share recommendations and insights on selecting third-line oral therapies for mCRC in China. In general, third-line treatment options for mCRC are mainly regorafenib, fruquintinib, and chemo/targeted therapy reintroduction, while FTD/TPI was rarely used in China probably due to poor accessibility. Fruquintinib is preferred in patients with poor performance status (PS), elder age, and severe organ dysfunction, compared to regorafenib. New drugs of clinical trials were more recommended for the patients with BRAF mutant tumor, and those with good previous treatment efficacy tended to be recommended for chemo/targeted therapy reintroduction. The management of mCRC is evolving, and it must be emphasized that the consideration and recommendations presented here reflect current treatment practices in China and thus might change according to new clinical data as well as the availability of new oral drugs.

Predictive factors associated with relapse of stage II/III colon cancer treated with peroral anti-cancer agents in the adjuvant setting

Postoperative adjuvant chemotherapy for patients with stage III colon cancer (CC) is regarded as the standard treatment worldwide for outcome improvement and relapse prevention. Similarly, high-risk stage II CC requires adjuvant chemotherapy because of its high recurrence rate. Previous randomized controlled trials showed that oxaliplatin (OX), in addition to fluorinated pyrimidine-based therapy for patients with stage II/III CC, significantly improves cancer survival but it remains controversial as to which patient groups should receive OX-containing regimens. Among 1,150 consecutive patients who underwent curative resection for stage II/III CC between 2009 and 2016 at two tertiary hospitals, 349 patients treated with only peroral (PO) fluorinated pyrimidine-based chemotherapy and 149 patients who received fluorinated pyrimidine-based chemotherapy with OX as adjuvant chemotherapy were retrospectively reviewed. The primary outcome was recurrence-free survival (RFS). Clinicopathological factors were more advanced in patients treated with OX than in patients treated only with PO fluorinated pyrimidine agents. Multivariate analysis for 5-year RFS showed that T4 [hazard ratio (HR), 2.947; P=0.0001], N2 (HR, 2.704; P=0.0075), vessel or lymphatic invasion (HR, 1.675; P=0.0437) and high cancer antigen (CA)19-9 (HR 3.367, P=0.0002) levels were independent risk factors of cancer relapse. Propensity score matching analysis was performed to match clinicopathological differences between the PO and OX groups. After matching, subgroup analysis of the patients showed that greater effects of OX on cancer survival were observed in patients in the OX group with high CA19-9 levels and tended to be associated with T4 and N2 compared with the PO group. Thus, OX-containing regimens should be recommended for patients with CC with these factors in an adjuvant setting.

S-1 and Capecitabine for the Treatment of Colorectal Cancer: A Meta-Analysis

Colorectal cancers common tumors that develop in the large intestines. The incidence of colorectal cancer is second only to gastric and esophageal cancers. Both S-1 and capecitabine are the third-generation fluorouracil-based chemotherapeutic drugs. We hope to summarize the therapeutic effects of tecotae and capecitabine in patients with colorectal cancer through this Meta-analysis. We performed a meta-analysis of the findings in the current literature. We performed a systematic review of outcomes associated with S-1 and capecitabine used to treat advanced colorectal cancer based on findings from both English and Chinese publications listed in PubMed, Embase, CNKI, Wanfang, EBSCO, Web of Science and the Cochrane Library. End-points included ORR, DCR, OS, and PFS; adverse events (grades 1–2 and 3–4) were also evaluated. Statistical analysis was performed using RevMan 5.3. A total of 12 studies were eventually included, involving a total of 3,375 patients. Of this group, 1,683 and 1,692 patients underwent treatment with S-1 or capecitabine, respectively. There were no greatly differences with respect to ORR, DCR, or OS; however, PFS was bettered in the group of S-1 compared to those treated with capecitabine. The incidence of leukopenia, diarrhea and anorexia were all higher among those in S-1 group compared to the capecitabine group, but a higher incidence of hand-foot syndrome was linked with use of capecitabine. Use of S-1 for the treatment of colorectal cancer may result in superior outcomes when compared to use of capecitabine.

S-1 and oxaliplatin versus tegafur-uracil and leucovorin as post-operative adjuvant chemotherapy in patients with high-risk stage III colon cancer: updated 5-year survival of the phase III ACTS-CC 02 trial

Background

The ACTS-CC 02 trial demonstrated that S-1 plus oxaliplatin (SOX) was not superior to tegafur-uracil and leucovorin (UFT/LV) in terms of disease-free survival (DFS) as adjuvant chemotherapy for high-risk stage III colon cancer (any T, N2, or positive nodes around the origin of the feeding arteries). We now report the final overall survival (OS) and subgroup analysis according to the pathological stage (TNM 7th edition) for treatment efficacy.

Patients and methods

Patients who underwent curative resection for pathologically confirmed high-risk stage III colon cancer were randomly assigned to receive either UFT/LV (300 mg/m² of UFT and 75 mg/day of LV on days 1-28, every 35 days, five cycles) or SOX (100 mg/m² of oxaliplatin on day 1 and 80 mg/m²/day of S-1 on days 1-14, every 21 days, eight cycles). The primary endpoint was DFS and the patients’ data were updated in February 2020.

Results

A total of 478 patients in the UFT/LV group and 477 patients in the SOX group were included in the final analysis. With a median follow-up time of 74.3 months, the 5-year DFS rate was 55.2% in the UFT/LV group and 58.1% in the SOX group [stratified hazard ratio (HR) 0.92; 95% confidence interval (CI) 0.76-1.11; P = 0.3973], and the 5-year OS rates were 78.3% and 79.1%, respectively (stratified HR 0.97; 95% CI 0.76-1.24; P = 0.8175). In the subgroup analysis, the 5-year OS rates in patients with T4N2b disease were 51.0% and 64.1% in the UFT/LV and SOX groups, respectively (HR 0.72; 95% CI 0.40-1.31).

Conclusion

Our final analysis reconfirmed that SOX as adjuvant chemotherapy is not superior to UFT/LV in terms of DFS in patients with high-risk stage III colon cancer. The 5-year OS rate was similar in the UFT/LV and SOX groups.

•

This final analysis reconfirmed that SOX is not superior to UFT/LV in high-risk stage III colon cancer in terms of DFS.

•

With a median follow-up time of 74.3 months, the 5-year OS rate was similar in both groups.

•

The 5-year OS rates in patients with T4N2b disease were 51.0% and 64.1% in the UFT/LV and SOX groups, respectively.

Short-term outcomes of preoperative chemoradiotherapy with S-1 for locally advanced rectal cancer

The purpose of the present study was to evaluate the short-term results of preoperative chemoradiation therapy with S-1 for locally advanced rectal cancer. A total of 32 patients with advanced rectal cancer who had been treated with preoperative chemoradiotherapy with S-1 and underwent surgical resection between May 2012 and December 2019 were analyzed. Advanced rectal cancer of clinical stage II and III was diagnosed in 13 (41%) and 19 (59%) patients, respectively. Therapeutic toxicities of anemia (24 patients; 75%), anal pain (22 patients; 69%) and skin and subcutaneous tissue disorders (19 patients; 59%) were frequently observed in all grades. Grade ≥3 leukopenia, anemia, neutrophil count reduction, platelet count reduction and diarrhea were identified in 2 (6%), 1 (3%), 1 (3%), 1 (3%) and 1 (3%) patients, respectively. A total of 29 patients (91%) completed this therapy without any change to the protocol or dosage. R0 resection was performed in 100% of the patients, and no postoperative mortality was observed. Pathological complete response was observed in 9 cases (28.1%). This therapy can be considered for cases of locally advanced rectal cancer due to its acceptable toxicity and relatively high antitumor effect.

Quality of adverse event reporting in phase III randomized controlled trials of breast and colorectal cancer: A systematic review

BACKGROUND

Clinical trial reports often emphasize efficacy over harms, leading to misinterpretation of the risk-to-benefit ratio of new therapies. Clear and sufficiently detailed reporting of methods and results is especially important in the abstracts of trial reports, as readers often base their assessment of a trial on such information. In this study, we evaluated the quality of adverse event (AE) reporting and abstract quality in phase III randomized controlled trials (RCTs) of systemic therapies in breast and colorectal cancer.

METHODS

Medline, EMBASE, Cochrane Database of RCTs, and Cochrane Database of Systematic Reviews were searched from November 2005 to September 2018. Phase III RCTs evaluating systemic therapies in breast or colorectal cancer were included. Each article was independently reviewed by two investigators using a standardized data extraction form based on guidelines developed by the Consolidated Standards of Reporting Trials (CONSORT) group. Descriptive statistics, bivariate analysis, and multivariable linear regression were used to analyze data. All statistical tests were two-sided.

RESULTS

Of 166 RCTs identified, 99.4% reported harms in the manuscript body, and 59.6% reported harms in the abstract. Reporting was restricted to severe harms in 15.6% of RCTs. Statistical comparison of AE rates went unreported in 59.0% of studies. Information regarding AEs leading to dose reductions, treatment discontinuations, or study withdrawals went unreported in 59.3%, 18.7%, and 86.8% of studies, respectively. Recently published RCTs (P = .009) and those sponsored at least partially by for-profit companies (P = .003) had higher abstract quality scores.

CONCLUSIONS

Breast and colorectal cancer phase III RCTs inadequately report CONSORT-compliant AE data. Improved guideline adherence and abstract reporting is required to properly weigh benefits and harms of new oncologic therapies.

SYSTEMATIC REVIEW REGISTRATION NUMBER

CRD42019140673.

Challenges of improving treatment outcomes for colorectal and anal cancers in Japan: the Colorectal Cancer Study Group (CCSG) of the Japan Clinical Oncology Group (JCOG)

Colorectal cancer is a major public health concern in Japan. While early-stage colorectal adenocarcinoma treatment entails radical resection of the primary tumor, the importance of perioperative treatment is growing as physicians seek to further improve treatment outcomes. For anal squamous cell carcinoma, definitive chemoradiotherapy is superior to radical surgery in terms of improved patient quality of life. The Colorectal Cancer Study Group of the Japanese Clinical Oncology Group was established in 2001 and has worked to provide answers to common clinical questions and improve treatment outcomes for colorectal and anal cancers through 15 large-scale prospective clinical trials. Here, we discuss the current state of perioperative treatment for early-stage colon, rectal and anal cancers in Japan and approaches taken by the Colorectal Cancer Study Group/the Japanese Clinical Oncology Group to improve treatment outcomes for these cancers.

Guidelines for time-to-event end-point definitions in adjuvant randomised trials for patients with localised colon cancer: Results of the DATECAN initiative

BACKGROUND

The variability of definitions for time-to-event (TTE) end-points impacts the conclusions of randomised clinical trials (RCTs). The Definition for the Assessment of Time-to-event Endpoints in CANcer (DATECAN) initiative aims to provide consensus definitions for TTE end-points used in RCTs. Here, we formulate guidelines for adjuvant colon cancer RCTs.

METHODS

We performed a literature review to identify TTE end-points and events included in their definition in RCT publications. Then, a consensus was reached among a panel of international experts, using a formal modified Delphi method, with 2 rounds of questionnaires and an in-person meeting.

RESULTS

Twenty-four experts scored 72 events involved in 6 TTE end-points. Consensus was reached for 24%, 57% and 100% events after the first round, second round and in-person meeting. For RCTs not using overall survival as their primary end-point, the experts recommend using disease-free survival (DFS) rather than recurrence-free survival (RFS) or time to recurrence (TTR) as the primary end-point. The consensus definition of DFS includes all causes of death, second primary colorectal cancers (CRCs), anastomotic relapse and metastatic relapse as an event, but not second primary non-CRCs. Events included in the RFS definition are the same as for DFS with the exception of second primary CRCs. The consensus definition of TTR includes anastomotic or metastatic relapse, death with evidence of recurrence and death from CC cause.

CONCLUSION

Standardised definitions of TTE end-points ensure the reproducibility of the end-points between RCTs and facilitate cross-trial comparisons. These definitions should be integrated in standard practice for the design, reporting and interpretation of adjuvant CC RCTs.

Influence of chemoradiotherapy on nutritional status in locally advanced rectal cancer: Prospective multicenter study

OBJECTIVE

The aim of this study was to investigate the influence of chemoradiotherapy (CRT) on nutritional status and the association between changes in nutritional status and clinical outcomes (treatment completion, adverse events, perioperative complications, and relapse-free survival [RFS]) in patients with locally advanced rectal cancer (LARC).

METHODS

In this multicenter, phase II study, 41 patients with LARC underwent CRT for 5 wk, followed by a 6- to 8-wk interval before surgery. Body weight, body mass index (BMI), lean body mass, serum albumin, and prealbumin levels were measured before (pre-), during, and after CRT, and before surgery. Changes in these data and scores on the Malnutrition Universal Screening Tool (MUST) were calculated based on pre-CRT status.

RESULTS

Twelve patients (29.3%) experienced body weight loss (BWL) ≥5% (defined as malnutrition) after CRT (P < 0.001) and before surgery (P = 0.035). Significant changes were seen in serum albumin levels and BMI during and after CRT (P < 0.001), and in MUST scores after CRT (P = 0.003) and before surgery (P = 0.035). Treatment completion was significantly associated with BWL (P = 0.028), MUST score (P = 0.013), and decreased serum albumin level (P = 0.001) after CRT. Regarding adverse events, MUST score before surgery (P = 0.009) and serum albumin level after CRT (P = 0.002) were significantly associated with diarrhea severity. Serum albumin level during CRT was associated with the onset of neutropenia (P = 0.005). No association was found between BWL and RFS.

CONCLUSIONS

These findings suggest that malnutrition and changes in nutritional status are not only commonly observed after CRT, but also associated with treatment completion and adverse events.

Efficacy and feasibility of S-1 plus oxaliplatin (C-SOX) for treating patients with stage III colon cancer (KSCC1303): final analysis of 3-year disease-free survival

BACKGROUND

Adjuvant chemotherapy is an accepted treatment to improve survival rates in patients with stage III colon cancer, and regimens including oxaliplatin have been shown to be superior to those containing 5-FU alone. The purpose of this study was to examine the efficacy and feasibility of S-1 plus oxaliplatin (C-SOX) as adjuvant chemotherapy for patients with stage III colon cancer following curative resection.

METHODS

Patients with colon cancer who underwent curative resection were enrolled and received oral S-1 40-60 mg twice daily on days 1-14 every 3 weeks plus intravenous oxaliplatin 130 mg/m² on day 1 for eight courses. The primary endpoint was 3-year disease-free survival rate. Secondary endpoints were the rate of treatment completion, adverse events, relative dose intensity, and overall survival.

RESULTS

Between February 2014 and December 2014, 89 patients were enrolled. One patient was excluded from the analysis because of ineligibility, and the remaining 88 patients were included. The rate of protocol treatment completion was 72.3%. The relative dose intensity of S-1 and oxaliplatin was 72% and 76.3%, respectively. Hematological severe adverse events (Grade 3/4) were neutropenia (21.3%) and thrombocytopenia (15.7%). The most frequent symptom was diarrhea (Grade 3/4: 5.6%). The incidence of grade 2 neuropathy has decreased from 8.1 to 2.7% after 3 years of the therapy. Three-year disease-free survival rate was 73.9% (95% CI 63.8-81.9), and 3-year overall survival rate was 94.3% (95% CI 86.8-97.6) CONCLUSIONS: C-SOX is a safe and feasible adjuvant chemotherapy regimen in patients with stage III colon cancer undergoing curative resection.

Effect of adjuvant chemotherapy on survival benefit in stage III colon cancer patients stratified by age: a Japanese real-world cohort study

Background

Adjuvant chemotherapy is relatively underused in older patients with colon cancer in Japan, and its age-specific effects on clinical outcomes remain unclear. This study aimed to assess the effect of adjuvant chemotherapy on survival benefit in stage III colon cancer patients stratified by age in a Japanese real-world setting.

Methods

In this multi-center retrospective cohort study, we analyzed patient-level information through a record linkage of population-based cancer registry data and administrative claims data. The study population comprised patients aged ≥18 years who received a pathological diagnosis of stage III colon cancer and underwent curative resection between 2010 and 2014 at 36 cancer care hospitals in Osaka Prefecture, Japan. Patients were divided into two groups based on age at diagnosis (< 75 and ≥ 75 years). The effect of adjuvant chemotherapy was analyzed using Cox proportional hazards regression models for all-cause mortality with inverse probability weighting of propensity scores. Adjusted hazard ratios were estimated for both age groups.

Results

A total of 783 patients were analyzed; 476 (60.8%) were aged < 75 years and 307 (39.2%) were aged ≥75 years. The proportion of older patients who received adjuvant chemotherapy (36.8%) was substantially lower than that of younger patients (73.3%). In addition, the effect of adjuvant chemotherapy was different between the age groups: the adjusted hazard ratio was 0.56 (95% confidence interval: 0.33–0.94, P = 0.027) in younger patients and 1.07 (0.66–1.74, P = 0.78) in older patients.

Conclusions

The clinical effectiveness of adjuvant chemotherapy in older patients with stage III colon cancer appears limited under current utilization practices.

Essential advances in surgical and adjuvant therapies for colorectal cancer 2018-2019

Surgical resection and adjuvant chemotherapy are the only treatment modalities for localized colorectal cancer that can obtain a "cure." The goal in surgically treating primary colorectal cancer is complete tumor removal along with dissection of systematic D3 lymph nodes. Adjuvant treatment controls recurrence and improves the prognosis of patients after they undergo R0 resection. Various clinical studies have promoted the gradual spread and clinical use of new surgical approaches such as laparoscopic surgery, robotic surgery, and transanal total mesorectal excision (TaTME). Additionally, the significance of adjuvant chemotherapy has been established and it is now recommended in the JSCCR (the Japanese Society for Cancer of the Colon and Rectum) guideline as a standard treatment. Herein, we review and summarize current surgical treatment and adjuvant chemotherapy for localized colorectal cancer and discuss recent advances in personalized medicine related to adjuvant chemotherapy.

Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines 2019 for the treatment of colorectal cancer

The number of deaths from colorectal cancer in Japan continues to increase. Colorectal cancer deaths exceeded 50,000 in 2016. In the 2019 edition, revision of all aspects of treatments was performed, with corrections and additions made based on knowledge acquired since the 2016 version (drug therapy) and the 2014 version (other treatments). The Japanese Society for Cancer of the Colon and Rectum guidelines 2019 for the treatment of colorectal cancer (JSCCR guidelines 2019) have been prepared to show standard treatment strategies for colorectal cancer, to eliminate disparities among institutions in terms of treatment, to eliminate unnecessary treatment and insufficient treatment and to deepen mutual understanding between healthcare professionals and patients by making these guidelines available to the general public. These guidelines have been prepared by consensuses reached by the JSCCR Guideline Committee, based on a careful review of the evidence retrieved by literature searches and in view of the medical health insurance system and actual clinical practice settings in Japan. Therefore, these guidelines can be used as a tool for treating colorectal cancer in actual clinical practice settings. More specifically, they can be used as a guide to obtaining informed consent from patients and choosing the method of treatment for each patient. Controversial issues were selected as clinical questions, and recommendations were made. Each recommendation is accompanied by a classification of the evidence and a classification of recommendation categories based on the consensus reached by the Guideline Committee members. Here, we present the English version of the JSCCR guidelines 2019.

Efficacy of oral administration of cystine and theanine in colorectal cancer patients undergoing capecitabine-based adjuvant chemotherapy after surgery: a multi-institutional, randomized, double-blinded, placebo-controlled, phase II trial (JORTC-CAM03)

Purpose

Capecitabine-based adjuvant chemotherapy for colorectal cancer patients often causes adverse events (AEs), such as diarrhea, stomatitis, anorexia, and hand-foot syndrome (HFS). Cystine and theanine were reported to attenuate some chemotherapy-associated AEs, and hence are also expected to attenuate capecitabine-induced AEs. Therefore, we aimed to investigate the safety and efficacy of cystine/theanine treatment in colorectal cancer patients undergoing capecitabine-based adjuvant chemotherapy after surgery.

Methods

A total of 100 colorectal cancer patients treated with capecitabine as an adjuvant chemotherapy after surgery were randomly allocated into the cystine/theanine group (n = 52) or the placebo group (n = 48). The primary endpoint was incidence rate of diarrhea of grade 1 or higher in accordance with the Common Terminology Criteria for AEs (CTCAE) v.4.0, Japanese Clinical Oncology Group (JCOG) version. The secondary endpoints included incidence rates of other AEs (CTCAE v.4.0-JCOG), as well as the incidence rate of HFS according to the HFS grading scale.

Results

There were no significant differences in capecitabine-induced AEs between the two groups. However, the incidence rate of diarrhea of grade 1 or higher tended to be lower in the cystine/theanine group than the placebo group (18.4% vs. 28.9%, p = 0.169) as well as the incidence rate of HFS of grade 1 or higher (CTCAE v.4.0-JCOG or HFS grading scale) (67.4% vs. 77.8%, p = 0.185, 67.3% vs. 80.0%, p = 0.124, respectively).

Conclusion

This trial demonstrated that cystine/theanine treatment of colorectal cancer patients undergoing capecitabine-based adjuvant chemotherapy after surgery is safe and has the tendency to reduce the incidence rate of diarrhea or HFS.

Trial registration

UMIN000024784

Electronic supplementary material

The online version of this article (10.1007/s00520-019-05205-1) contains supplementary material, which is available to authorized users.

S-1 and Oxaliplatin Versus Tegafur-uracil and Leucovorin as Postoperative Adjuvant Chemotherapy in Patients With High-risk Stage III Colon Cancer (ACTS-CC 02): A Randomized, Open-label, Multicenter, Phase III Superiority Trial

BACKGROUND

The efficacy of S-1 plus oxaliplatin (SOX) as postoperative adjuvant chemotherapy for colon cancer has not been established. This randomized phase III study was designed to verify the superiority of SOX over tegafur-uracil and leucovorin (UFT/LV) in patients with high-risk stage III colon cancer (any T, N2, or positive nodes around the origin of the feeding arteries).

PATIENTS AND METHODS

Patients who underwent curative resection for pathologically confirmed high-risk stage III colon cancer were randomly assigned to receive either UFT/LV (300 mg/m² of UFT and 75 mg/day of LV on days 1-28, every 35 days, 5 cycles) or SOX (100 mg/m² of oxaliplatin on day 1 and 80 mg/m² of S-1 on days 1-14, every 21 days, 8 cycles). The primary endpoint was disease-free survival (DFS).

RESULTS

A total of 478 patients in the UFT/LV group and 477 patients in the SOX group were included in the primary analysis. The 3-year DFS was 60.6% (95% confidence interval [CI], 56.0%-64.9%) in the UFT/LV group and 62.7% (95% CI, 58.1%-66.9%) in the SOX group. The stratified hazard ratio for DFS was 0.90 (95% CI, 0.74-1.09; stratified log-rank test, P = .2780). In the N2b subgroup, the 3-year DFS was 46.0% (95% CI, 37.5%-54.0%) in the UFT/LV group and 54.7% (95% CI, 45.7%-62.7%) in the SOX group (hazard ratio, 0.76; 95% CI, 0.55-1.05).

CONCLUSION

As postoperative adjuvant chemotherapy, SOX was not superior to UFT/LV in terms of DFS in patients with high-risk stage III colon cancer.

Safety and efficacy of a modified XELOX adjuvant regimen for patients with operated stage III colon cancer: a Chinese single-center experience

Background

A fixed 8-cycle oxaliplatin and capecitabine (XELOX) regimen has been the standard adjuvant therapy for patients with stage III colon cancer. However, completing the full-cycle of oxaliplatin is often associated with severe neurotoxicity. To spare patients from the toxic effects, without comprising the required efficacy, we evaluated the safety and efficacy of a modified XELOX (mXELOX) adjuvant chemotherapy regimen with 6 cycles of oxaliplatin and a full cycle of capecitabine.

Methods

We retrospectively analyzed 330 eligible patients with stage III colon cancer who underwent curative tumor resection followed by mXELOX, standard XELOX or unfinished XELOX adjuvant chemotherapy between December 2007 and April 2015. Associated prognostic factors were investigated and their disease-free survival (DFS) and overall survival (OS) rates were also determined and compared among the different regimen groups.

Results

Compared with the standard XELOX group, the mXELOX group had lower total incidence rates of neurotoxicity (39.3% vs. 76.2%, P < 0.001), leucopenia (53.6% vs. 69.8%, P = 0.017) and thrombocytopenia (38.1% vs. 56.3%, P = 0.011). The standard XELOX and mXELOX adjuvant chemotherapy regimens presented with comparable 3-year DFS rates (86.3% vs. 89.2%; P = 0.838) and 3-year OS rates (92.7% vs. 97.6%; P = 0.227). Compared to unfinished XELOX chemotherapy, the oncologic benefits of the mXELOX regimen were greater for patients with T4 tumors (3-year DFS: Hazard ratio [HR], 2.184; 95% confidence interval [CI], 1.051–4.540; P = 0.036; 3-year OS: HR, 4.529; 95% CI 1.245–16.479; P = 0.022) and for high-risk patients (3-year DFS: HR, 1.962; 95% CI 0.964–3.993; P = 0.044; 3-year OS: HR, 4.193; 95% CI 1.182–14.874; P = 0.026).

Conclusions

The mXELOX adjuvant chemotherapy presented a comparable survival benefit and lower incidence of toxicity than standard XELOX chemotherapy. It could be an alternative treatment for high-risk patients with operated stage III colon cancer.

JOIN trial: treatment outcome and recovery status of peripheral sensory neuropathy during a 3-year follow-up in patients receiving modified FOLFOX6 as adjuvant treatment for stage II/III colon cancer

Purpose

Adjuvant FOLFOX therapy is an established standard-of-care for resected colon cancer. Peripheral sensory neuropathy (PSN) is regarded as the major toxicity issue related to FOLFOX therapy. There have been a few reports on the recovery status from PSN thereafter. JOIN trial investigated the tolerability and efficacy of adjuvant modified FOLFOX6 (mFOLFOX6) in Japanese patients with stage II/III colon cancer.

Methods

Twelve cycles of mFOLFOX6 were given to patients with stage II/III curatively resected colon cancer. Treatment outcomes, including disease-free survival (DFS), relapse-free survival (RFS), overall survival (OS), and recovery status of PSN during 3-year follow-up, were investigated.

Results

Of the 882 patients enrolled from 2010 to 2012, 864 were eligible for the efficacy analyses. Three-year DFS, RFS, and OS were favorable in 92.1, 92.8, and 97.4% of stage II patients; 76.4, 77.9, and 93.8% of stage IIIA/B; and 61.6, 62.7, and 85.9% of stage IIIC, respectively. The cumulative incidence of PSN during treatment was 47.8% in grade 1 (G1), 30.3% in G2, and 5.8% in G3. For those with G3 PSN during treatment, there was gradual recovery in 1.1% of patients at 12 months after enrollment, 0.5% at 24 months, and 0.2% at 36 months. However, G1 or G2 residual PSN after 3 years was observed in 21.0% (18.7%, G1; 2.3%, G2).

Conclusions

Adjuvant mFOLFOX6 therapy was effective and well tolerated in patients with stage II/III colon cancer. Most patients recovered from G3 PSN related to oxaliplatin, but approximately 20% of patients had G1 or G2 PSN at 3-year follow-up.

Electronic supplementary material

The online version of this article (10.1007/s00280-019-03957-5) contains supplementary material, which is available to authorized users.

Impact of primary tumor location as a predictive factor in patients suffering from colorectal cancer treated with cytotoxic anticancer agents based on the collagen gel droplet-embedded drug sensitivity test

In recent studies, better clinical outcomes for patients with left-sided colon cancer (CC) compared with right-sided CC have been reported; however, in such investigations, the chemotherapy regimens included molecular-targeting agents. To the best of our knowledge, the impact of primary tumor location as a predictive factor in patients suffering from CC treated with cytotoxic anticancer agents alone has not been investigated. The aim of the present study was to determine the impact of the primary tumor location as a predictive factor of patients undergoing the following cytotoxic anticancer agent regimens: Leucovorin and fluorouracil + oxaliplatin (FOLFOX) or Leucovorin and fluorouracil + irinotecan (FOLFIRI), using the collagen gel droplet-embedded drug sensitivity test (CD-DST). Between March 2008 and April 2017, tumor specimens were obtained from 133 patients suffering from colorectal cancer (CRC) who had not received preoperative chemotherapy. CD-DST was performed and the growth inhibition rate (IR) was determined in FOLFOX and FOLFIRI regimens. The associations between tumor location and IR values for each condition were evaluated. In the present study, the prognosis of patients receiving palliative chemotherapy as well as treatment with molecularly-targeted agents was also investigated. There were no significant differences in the IRs (%) of the two regimens using CD-DST for right-sided tumors compared with left-sided tumors, including or excluding the rectum. The median survival times of patients with right CC and left CC who had received palliative chemotherapy and treatment with molecularly-targeted agents were 960 and 1,348 days, respectively. Primary tumor location did not represent a predictive factor for the efficacy of treatment with cytotoxic anticancer agent regimens using CD-DST. However, patients suffering from left-sided CC were revealed to exhibit better clinical outcomes compared with patients suffering from right-sided CC when molecularly-targeted agent regimens were administered. Therefore, the results of the present study suggested that molecularly-targeted agents rather than cytotoxic anticancer agents may result in improved clinical outcomes for patients with CRC suffering from left-sided tumors.

Impact of primary tumor location as a predictive factor in patients suffering from colorectal cancer treated with cytotoxic anticancer agents based on the collagen gel droplet-embedded drug sensitivity test

In recent studies, better clinical outcomes for patients with left-sided colon cancer (CC) compared with right-sided CC have been reported; however, in such investigations, the chemotherapy regimens included molecular-targeting agents. To the best of our knowledge, the impact of primary tumor location as a predictive factor in patients suffering from CC treated with cytotoxic anticancer agents alone has not been investigated. The aim of the present study was to determine the impact of the primary tumor location as a predictive factor of patients undergoing the following cytotoxic anticancer agent regimens: Leucovorin and fluorouracil + oxaliplatin (FOLFOX) or Leucovorin and fluorouracil + irinotecan (FOLFIRI), using the collagen gel droplet-embedded drug sensitivity test (CD-DST). Between March 2008 and April 2017, tumor specimens were obtained from 133 patients suffering from colorectal cancer (CRC) who had not received preoperative chemotherapy. CD-DST was performed and the growth inhibition rate (IR) was determined in FOLFOX and FOLFIRI regimens. The associations between tumor location and IR values for each condition were evaluated. In the present study, the prognosis of patients receiving palliative chemotherapy as well as treatment with molecularly-targeted agents was also investigated. There were no significant differences in the IRs (%) of the two regimens using CD-DST for right-sided tumors compared with left-sided tumors, including or excluding the rectum. The median survival times of patients with right CC and left CC who had received palliative chemotherapy and treatment with molecularly-targeted agents were 960 and 1,348 days, respectively. Primary tumor location did not represent a predictive factor for the efficacy of treatment with cytotoxic anticancer agent regimens using CD-DST. However, patients suffering from left-sided CC were revealed to exhibit better clinical outcomes compared with patients suffering from right-sided CC when molecularly-targeted agent regimens were administered. Therefore, the results of the present study suggested that molecularly-targeted agents rather than cytotoxic anticancer agents may result in improved clinical outcomes for patients with CRC suffering from left-sided tumors.

Updated 5-year survival and exploratory T x N subset analyses of ACTS-CC trial: a randomised controlled trial of S-1 versus tegafur-uracil/leucovorin as adjuvant chemotherapy for stage III colon cancer

Objective

Adjuvant Chemotherapy Trial of TS-1 for Colon Cancer (ACTS-CC), a randomised phase III trial, demonstrated that adjuvant therapy with S-1 for stage III colon cancer was non-inferior in 3-year disease-free survival (DFS) to that of tegafur-uracil plus leucovorin (UFT/LV). We updated DFS and overall survival (OS) and performed T x N subset analysis.

Methods

A total of 1518 patients with curatively resected stage III colon cancer were randomly assigned to receive S-1 (80-120  mg/day on days 1-28 every 42 days, four courses) or UFT/LV (UFT: 300-600  mg/day and LV: 75  mg/day on days 1-28 every 35 days, five courses).

Results

The 5-year DFS rates of the S-1 and UFT/LV group were 70.2 % and 66.9 %, respectively (HR 0.88; 95%  CI 0.74 to 1.06; p=0.177), and non-inferiority of DFS was reconfirmed with a median of 63.5-month follow-up. The similarity of OS was also confirmed (HR 0.92; 95%  CI 0.72 to 1.17; p=0.488); 5-year OS rates of the S-1 and UFT/LV group were 86.0 % and 84.4 %, respectively. No significant interactions were identified between the major baseline characteristics and DFS of the S-1 and UFT/LV groups, except for histological type; S-1 was more favourable in patients with poorly differentiated adenocarcinoma. Patient outcomes were well separated by TNM-substages (IIIA/IIIB/IIIC). With the patients divided into 20 subsets by T and N factors, the DFS and OS rates of T3 and N1 subset, which accounted for 62 % of stage IIIB patients and 44 % of all studied subjects, were significantly better than those of the other subsets in stage IIIB and similar to those of stage IIIA.

Conclusions

Adjuvant therapy of S-1 for stage III colon cancer was reconfirmed to be non-inferior in DFS to those of UFT/LV after long follow-up. No difference in OS was also demonstrated. T3N1 patients might be considered separately from other patients included in stage IIIB because of its favourable outcome.

Trial registration number

NCT00660894.