3 versus 6 months of adjuvant oxaliplatin-fluoropyrimidine combination therapy for colorectal cancer (SCOT): an international, randomised, phase 3, non-inferiority trial.

BACKGROUND: 6 months of oxaliplatin-containing chemotherapy is usually given as adjuvant treatment for stage 3 colorectal cancer. We investigated whether 3 months of oxaliplatin-containing chemotherapy would be non-inferior to the usual 6 months of treatment. METHODS: The SCOT study was an international, randomised, phase 3, non-inferiority trial done at 244 centres. Patients aged 18 years or older with high-risk stage II and stage III colorectal cancer underwent central randomisation with minimisation for centre, choice of regimen, sex, disease site, N stage, T stage, and the starting dose of capecitabine. Patients were assigned (1:1) to receive 3 months or 6 months of adjuvant oxaliplatin-containing chemotherapy. The chemotherapy regimens could consist of CAPOX (capecitabine and oxaliplatin) or FOLFOX (bolus and infused fluorouracil with oxaliplatin). The regimen was selected before randomisation in accordance with choices of the patient and treating physician. The primary study endpoint was disease-free survival and the non-inferiority margin was a hazard ratio of 1·13. The primary analysis was done in the intention-to-treat population and safety was assessed in patients who started study treatment. This trial is registered with ISRCTN, number ISRCTN59757862, and follow-up is continuing. FINDINGS: 6088 patients underwent randomisation between March 27, 2008, and Nov 29, 2013. The intended treatment was FOLFOX in 1981 patients and CAPOX in 4107 patients. 3044 patients were assigned to 3 month group and 3044 were assigned to 6 month group. Nine patients in the 3 month group and 14 patients in the 6 month group did not consent for their data to be used, leaving 3035 patients in the 3 month group and 3030 patients in the 6 month group for the intention-to-treat analyses. At the cutoff date for analysis, there had been 1482 disease-free survival events, with 740 in the 3 month group and 742 in the 6 month group. 3 year disease-free survival was 76·7% (95% CI 75·1-78·2) for the 3 month group and 77·1% (75·6-78·6) for the 6 month group, giving a hazard ratio of 1·006 (0·909-1·114, test for non-inferiority p=0·012), significantly below the non-inferiority margin. Peripheral neuropathy of grade 2 or worse was more common in the 6 month group (237 [58%] of 409 patients for the subset with safety data) than in the 3 month group (103 [25%] of 420) and was long-lasting and associated with worse quality of life. 1098 serious adverse events were reported (492 reports in the 3 month group and 606 reports in the 6 month group) and 32 treatment-related deaths occurred (16 in each group). INTERPRETATION: In the whole study population, 3 months of oxaliplatin-containing adjuvant chemotherapy was non-inferior to 6 months of the same therapy for patients with high-risk stage II and stage III colorectal cancer and was associated with reduced toxicity and improved quality of life. Despite the fact the study was underpowered, these data suggest that a shorter duration leads to similar survival outcomes with better quality of life and thus might represent a new standard of care. FUNDING: Medical Research Council, Swedish Cancer Society, NETSCC, and Cancer Research UK.

SCOT: a comparison of cost-effectiveness from a large randomised phase III trial of two durations of adjuvant Oxaliplatin combination chemotherapy for colorectal cancer.

BACKGROUND: The Short Course Oncology Therapy (SCOT) study is an international, multicentre, non-inferiority randomised controlled trial assessing the efficacy, toxicity, and cost-effectiveness of 3 months (3 M) versus the usually given 6 months (6 M) of adjuvant chemotherapy in colorectal cancer. METHODS: In total, 6088 patients with fully resected high-risk stage II or stage III colorectal cancer were randomised and followed up for 3-8 years. The within-trial cost-effectiveness analysis from a UK health-care perspective is presented using the resource use data, quality of life (EQ-5D-3L), time on treatment (ToT), disease-free survival after treatment (DFS) and overall survival (OS) data. Quality-adjusted partitioned survival analysis and Kaplan-Meier Sample Average Estimator estimated QALYs and costs. Probabilistic sensitivity and subgroup analysis was undertaken. RESULTS: The 3 M arm is less costly (-£4881; 95% CI: -£6269; -£3492) and entails (non-significant) QALY gains (0.08; 95% CI: -0.086; 0.230) due to a better significant quality of life. The net monetary benefit was significantly higher in 3 M under a wide range of monetary values of a QALY. The subgroup analysis found similar results for patients in the CAPOX regimen. However, for the FOLFOX regimen, 3 M had lower QALYs than 6 M (not statistically significant). CONCLUSIONS: Overall, 3 M dominates 6 M with no significant detrimental impact on QALYs. The results provide the economic case that a 3 M treatment strategy should be considered a new standard of care.

The value of additional bevacizumab in patients with high-risk stroma-high colon cancer. A study within the QUASAR2 trial, an open-label randomized phase 3 trial.

INTRODUCTION: Patients with a high stroma percentage within the primary tumor have a poor prognosis. In this study, we investigate whether anti-angiogenic therapy might improve survival of patients with a stroma-high profile with potentially increased angiogenesis. MATERIALS AND METHODS: Tissue samples of the primary tumor of 965 colon cancer patients participating in the QUASAR2 trial were analyzed for tumor-stroma ratio (TSR). Stroma-high (>50%) and stroma-low (≤50%) groups were evaluated with respect to survival. RESULTS: Disease free survival (DFS) was significantly lower in the stroma-high group (HR 1.53, 95%CI 1.19-1.95, P = 0.001). No difference in DFS was seen with respect to treatment with capecitabine alone (CAP) or capecitabine with bevacizumab (CAPBEV) (Stroma-high HR 1.00, 95%CI 0.69-1.46, P = 0.996; stroma-low HR 1.02, 95%CI 0.75-1.41, P = 0.883). A significant difference in survival was seen comparing groups with or without vascular invasion (DFS P < 0.001). A correlation between vascular invasion and stroma-high was seen (χ2 -test P = 0.043). DISCUSSION AND CONCLUSIONS: The TSR confirmed to be a strong prognosticator for disease-free survival in a selected high-risk patient population. No benefit was found in response to treatment with bevacizumab when stratified for TSR. TSR showed to have an additional prognostic value in patients with vascular invasion present in the primary tumor.

Adjuvant capecitabine plus bevacizumab versus capecitabine alone in patients with colorectal cancer (QUASAR 2): an open-label, randomised phase 3 trial.

BACKGROUND: Antiangiogenic agents have established efficacy in the treatment of metastatic colorectal cancer. We investigated whether bevacizumab could improve disease-free survival in the adjuvant setting after resection of the primary tumour. METHODS: For the open-label, randomised, controlled QUASAR 2 trial, which was done at 170 hospitals in seven countries, we recruited patients aged 18 years or older with WHO performance status scores of 0 or 1 who had undergone potentially curative surgery for histologically proven stage III or high-risk stage II colorectal cancer. Patients were randomly assigned (1:1) to receive eight 3-week cycles of oral capecitabine alone (1250 mg/m2 twice daily for 14 days followed by a break for 7 days) or the same regimen of oral capecitabine plus 16 cycles of 7·5 mg/kg bevacizumab by intravenous infusion over 90 min on day 1 of each cycle. Randomisation was done by a computer-generated schedule with use of minimisation with a random element stratified by age, disease stage, tumour site, and country. The study was open label and no-one was masked to treatment assignment. The primary endpoint was 3-year disease-free survival, assessed in the intention-to-treat population. Toxic effects were assessed in patients who received at least one dose of randomised treatment. This trial is registered with the ISRCTN registry, number ISRCTN45133151. FINDINGS: Between April 25, 2005, and Oct 12, 2010, 1952 eligible patients were enrolled, of whom 1941 had assessable data (968 in the capecitabine alone group and 973 in the capecitabine and bevacizumab group). Median follow-up was 4·92 years (IQR 4·00-5·16). Disease-free survival at 3 years did not differ between the groups (75·4%, 95% CI 72·5-78·0 in the capecitabine and bevacizumab group vs 78·4%, 75·7-80·9 in the capecitabine alone group; hazard ratio 1·06, 95% CI 0·89-1·25, p=0·54). The most common grade 3-4 adverse events were hand-foot syndrome (201 [21%] of 963 in the capecitabine alone group vs 257 [27%] of 959 in the capecitabine and bevacizumab group) and diarrhoea (102 [11%] vs 104 [11%]), and, with the addition of bevacizumab, expected increases were recorded in all-grade hypertension (320 [33%] vs 75 [8%]), proteinuria (197 [21%] vs 49 [5%]), and wound healing problems (30 [3%] vs 17 [2%]). 571 serious adverse events were reported (221 with capecitabine alone and 350 with capecitabine and bevacizumab). Most of these were gastrointestinal (n=245) or cardiovascular (n=169). 23 deaths within 6 months of randomisation were classified as being related to treatment, eight in the capecitabine alone group and 15 in the capecitabine and bevacizumab group. INTERPRETATION: The addition of bevacizumab to capecitabine in the adjuvant setting for colorectal cancer yielded no benefit in the treatment of an unselected population and should not be used. FUNDING: Roche.

Time From Colorectal Cancer Surgery to Adjuvant Chemotherapy: Post Hoc Analysis of the SCOT Randomized Clinical Trial.

Importance: The timing of adjuvant chemotherapy after surgery for colorectal cancer and its association with long-term outcomes have been investigated in national cohort studies, with no consensus on the optimal time from surgery to adjuvant chemotherapy. Objective: To analyze the association between the timing of adjuvant chemotherapy after surgery for colorectal cancer and disease-free survival. Design, Setting, and Participants: This is a post hoc analysis of the phase 3 SCOT randomized clinical trial, from 244 centers in 6 countries, investigating the noninferiority of 3 vs 6 months of adjuvant chemotherapy. Patients with high-risk stage II or stage III nonmetastatic colorectal cancer who underwent curative-intended surgery were randomized to either 3 or 6 months of adjuvant chemotherapy consisting of fluoropyrimidine and oxaliplatin regimens. Those with complete information on the date of surgery, treatment type, and long-term follow-up were investigated for the primary and secondary end points. Data were analyzed from May 2022 to February 2024. Intervention: In the post hoc analysis, patients were grouped according to the start of adjuvant chemotherapy being less than 6 weeks vs greater than 6 weeks after surgery. Main Outcomes and Measures: The primary end point was disease-free survival. The secondary end points were adverse events in the total treatment period or the first cycle of adjuvant chemotherapy. Results: A total of 5719 patients (2251 [39.4%] female; mean [SD] age, 63.4 [9.3] years) were included in the primary analysis after data curation; among them, 914 were in the early-start group and 4805 were in the late-start group. Median (IQR) follow-up was 72.0 (47.3-88.1) months, with a median (IQR) of 56 (41-66) days from surgery to chemotherapy. Five-year disease-free survival was 78.0% (95% CI, 75.3%-80.8%) in the early-start group and 73.2% (95% CI, 72.0%-74.5%) in the late-start group. In an adjusted Cox regression analysis, the start of adjuvant chemotherapy greater than 6 weeks after surgery was associated with worse disease-free survival (hazard ratio, 1.24; 95% CI, 1.06-1.46; P = .01). In adjusted logistic regression models, there was no association with adverse events in the total treatment period (odds ratio, 0.82; 95% CI, 0.65-1.04; P = .09) or adverse events in the first cycle of treatment (odds ratio, 0.77; 95% CI, 0.56-1.09; P = .13). Conclusions and Relevance: In this international population of patients with high-risk stage II and stage III colorectal cancer, starting adjuvant chemotherapy more than 6 weeks after surgery was associated with worse disease-free survival, with no difference in adverse events between the groups. Trial Registration: isrctn.org Identifier: ISRCTN59757862.

Non-Canonical Activin A Signaling Stimulates Context-Dependent and Cellular-Specific Outcomes in CRC to Promote Tumor Cell Migration and Immune Tolerance.

We have shown that activin A (activin), a TGF-ß superfamily member, has pro-metastatic effects in colorectal cancer (CRC). In lung cancer, activin activates pro-metastatic pathways to enhance tumor cell survival and migration while augmenting CD4+ to CD8+ communications to promote cytotoxicity. Here, we hypothesized that activin exerts cell-specific effects in the tumor microenvironment (TME) of CRC to promote anti-tumoral activity of immune cells and the pro-metastatic behavior of tumor cells in a cell-specific and context-dependent manner. We generated an Smad4 epithelial cell specific knockout (Smad4-/-) which was crossed with TS4-Cre mice to identify SMAD-specific changes in CRC. We also performed IHC and digital spatial profiling (DSP) of tissue microarrays (TMAs) obtained from 1055 stage II and III CRC patients in the QUASAR 2 clinical trial. We transfected the CRC cells to reduce their activin production and injected them into mice with intermittent tumor measurements to determine how cancer-derived activin alters tumor growth in vivo. In vivo, Smad4-/- mice displayed elevated colonic activin and pAKT expression and increased mortality. IHC analysis of the TMA samples revealed increased activin was required for TGF-ß-associated improved outcomes in CRC. DSP analysis identified that activin co-localization in the stroma was coupled with increases in T-cell exhaustion markers, activation markers of antigen presenting cells (APCs), and effectors of the PI3K/AKT pathway. Activin-stimulated PI3K-dependent CRC transwell migration, and the in vivo loss of activin lead to smaller CRC tumors. Taken together, activin is a targetable, highly context-dependent molecule with effects on CRC growth, migration, and TME immune plasticity.

Accounting for intensity variation in image analysis of large-scale multiplexed clinical trial datasets.

Multiplex immunofluorescence (mIF) imaging can provide comprehensive quantitative and spatial information for multiple immune markers for tumour immunoprofiling. However, application at scale to clinical trial samples sourced from multiple institutions is challenging due to pre-analytical heterogeneity. This study reports an analytical approach to the largest multi-parameter immunoprofiling study of clinical trial samples to date. We analysed 12,592 tissue microarray (TMA) spots from 3,545 colorectal cancers sourced from more than 240 institutions in two clinical trials (QUASAR 2 and SCOT) stained for CD4, CD8, CD20, CD68, FoxP3, pan-cytokeratin, and DAPI by mIF. TMA slides were multi-spectrally imaged and analysed by cell-based and pixel-based marker analysis. We developed an adaptive thresholding method to account for inter- and intra-slide intensity variation in TMA analysis. Applying this method effectively ameliorated inter- and intra-slide intensity variation improving the image analysis results compared with methods using a single global threshold. Correlation of CD8 data derived by our mIF analysis approach with single-plex chromogenic immunohistochemistry CD8 data derived from subsequent sections indicates the validity of our method (Spearman's rank correlation coefficients ρ between 0.63 and 0.66, p ≪ 0.01) as compared with the current gold standard analysis approach. Evaluation of correlation between cell-based and pixel-based analysis results confirms equivalency (ρ > 0.8, p ≪ 0.01, except for CD20 in the epithelial region) of both analytical approaches. These data suggest that our adaptive thresholding approach can enable analysis of mIF-stained clinical trial TMA datasets by digital pathology at scale for precision immunoprofiling.

3-month versus 6-month adjuvant chemotherapy for patients with high-risk stage II and III colorectal cancer: 3-year follow-up of the SCOT non-inferiority RCT.

BACKGROUND: Oxaliplatin and fluoropyrimidine chemotherapy administered over 6 months is the standard adjuvant regimen for patients with high-risk stage II or III colorectal cancer. However, the regimen is associated with cumulative toxicity, characterised by chronic and often irreversible neuropathy. OBJECTIVES: To assess the efficacy of 3-month versus 6-month adjuvant chemotherapy for colorectal cancer and to compare the toxicity, health-related quality of life and cost-effectiveness of the durations. DESIGN: An international, randomised, open-label, non-inferiority, Phase III, parallel-group trial. SETTING: A total of 244 oncology clinics from six countries: UK (England, Scotland, Wales and Northern Ireland), Denmark, Spain, Sweden, Australia and New Zealand. PARTICIPANTS: Adults aged ≥ 18 years who had undergone curative resection for high-risk stage II or III adenocarcinoma of the colon or rectum. INTERVENTIONS: The adjuvant treatment regimen was either oxaliplatin and 5-fluorouracil or oxaliplatin and capecitabine, randomised to be administered over 3 or 6 months. MAIN OUTCOME MEASURES: The primary outcome was disease-free survival. Overall survival, adverse events, neuropathy and health-related quality of life were also assessed. The main cost categories were chemotherapy treatment and hospitalisation. Cost-effectiveness was assessed through incremental cost comparisons and quality-adjusted life-year gains between the options and was reported as net monetary benefit using a willingness-to-pay threshold of £30,000 per quality-adjusted life-year per patient. RESULTS: Recruitment is closed. In total, 6088 patients were randomised (3044 per group) between 27 March 2008 and 29 November 2013, with 6065 included in the intention-to-treat analyses (3-month analysis, n = 3035; 6-month analysis, n = 3030). Follow-up for the primary analysis is complete. The 3-year disease-free survival rate in the 3-month treatment group was 76.7% (standard error 0.8%) and in the 6-month treatment group was 77.1% (standard error 0.8%), equating to a hazard ratio of 1.006 (95% confidence interval 0.909 to 1.114; p-value for non-inferiority = 0.012), confirming non-inferiority for 3-month adjuvant chemotherapy. Frequent adverse events (alopecia, anaemia, anorexia, diarrhoea, fatigue, hand-foot syndrome, mucositis, sensory neuropathy, neutropenia, pain, rash, altered taste, thrombocytopenia and watery eye) showed a significant increase in grade with 6-month duration; the greatest difference was for sensory neuropathy (grade ≥ 3 was 4% for 3-month vs.16% for 6-month duration), for which a higher rate of neuropathy was seen for the 6-month treatment group from month 4 to ≥ 5 years (p < 0.001). Quality-of-life scores were better in the 3-month treatment group over months 4-6. A cost-effectiveness analysis showed 3-month treatment to cost £4881 less over the 8-year analysis period, with an incremental net monetary benefit of £7246 per patient. CONCLUSIONS: The study achieved its primary end point, showing that 3-month oxaliplatin-containing adjuvant chemotherapy is non-inferior to 6 months of the same regimen; 3-month treatment showed a better safety profile and cost less. For future work, further follow-up will refine long-term estimates of the duration effect on disease-free survival and overall survival. The health economic analysis will be updated to include long-term extrapolation for subgroups. We expect these analyses to be available in 2019-20. The Short Course Oncology Therapy (SCOT) study translational samples may allow the identification of patients who would benefit from longer treatment based on the molecular characteristics of their disease. TRIAL REGISTRATION: Current Controlled Trials ISRCTN59757862 and EudraCT 2007-003957-10. 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. 23, No. 64. See the NIHR Journals Library website for further project information. This research was supported by the Medical Research Council (transferred to NIHR Evaluation, Trials and Studies Coordinating Centre - Efficacy and Mechanism Evaluation; grant reference G0601705), the Swedish Cancer Society and Cancer Research UK Core Clinical Trials Unit Funding (funding reference C6716/A9894).

Patients diagnosed with bowel cancer are likely to have surgery to remove the tumour. Patients diagnosed with a more advanced stage of the disease are then likely to be offered what is known as adjuvant chemotherapy ­ chemotherapy to kill any cancer cells that have already spread but cannot be seen. Adjuvant chemotherapy is usually given over 6 months using two medicines known as oxaliplatin and fluoropyrimidine. This chemotherapy has side effects of diarrhoea, nausea and vomiting, and it reduces the numbers of cells in the blood. It can also damage nerves, which causes discomfort, numbness and tingling; in some cases, this can go on for years. These side effects are more likely to develop with longer treatment. This study looked at whether or not shortening the time over which patients were given oxaliplatin and fluoropyrimidine chemotherapy reduced its effectiveness. In this large study of over 6000 patients, half of the patients were allocated by chance to be treated for 3 months and the other half to be treated for 6 months. Reducing the time that patients had chemotherapy from 6 months to 3 months did not make the treatment less effective. When patients treated with chemotherapy over 3 months were compared with those treated over 6 months, 77% of patients in both groups were well with no detectable disease 3 years after surgery. Patients were less likely to get side effects with 3-month chemotherapy. In particular, the chance of persistent long-term nerve damage was lower, resulting in patients with 3-month chemotherapy having better health-related quality of life. Overall, the study showed that 3-month adjuvant chemotherapy for patients with bowel cancer is as effective as 6-month adjuvant chemotherapy and causes fewer side effects.

Aberrant P53 expression lacks prognostic or predictive significance in colorectal cancer: results from the VICTOR trial.

AIM: Biomarkers with prognostic and predictive value can help stratify patients with colorectal cancer (CRC) into appropriate treatment groups. We sought to evaluate the clinical utility of P53 protein expression as a biomarker in VICTOR, a large phase III trial of rofecoxib in stage II and III CRC. PATIENTS AND METHODS: Tissue micro arrays were constructed from 884 tumors and the expression of P53 was examined by immunohistochemistry. Tumors were dichotomised as either P53-positive (nuclear expression in >10% of cells or the 'absent' pattern, both representing TP53 mutation) or P53-negative (nuclear expression in <10% of cells). RESULTS: Aberrant P53 expression was found in 65% (482/740) of patients. It was associated with distal location (p<0.001) and stage III disease (p<0.001). No effect was observed on disease-free or overall survival, and there was no interaction with chemotherapy or radiotherapy. CONCLUSION: Analysis of P53 expression in the patients recruited to the VICTOR trial confirmed that P53 expression is associated with site and stage of CRC. However, independently, this biomarker has neither prognostic nor predictive utility in this cohort of patients.