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.

The safety and efficacy of total mesorectal excision (TME) surgery following dose-escalation: Surgical outcomes from the organ preservation in early rectal adenocarcinoma (OPERA) trial, a European multicentre phase 3 randomised trial (NCT02505750).

AIM: Nonsurgical treatment with chemoradiotherapy for rectal cancer is gaining interest as it avoids total mesorectal excision (TME) surgery and stoma. The OPERA trial aims to evaluate whether dose escalation with contact X-ray brachytherapy (CXB) boost improves organ preservation compared to external beam radiotherapy (EBRT) boost. It has been suggested that dose escalation adversely affects surgical outcomes and therefore we report outcomes following TME in OPERA at 36 months. METHODS: OPERA is a European multicentre phase 3 trial (NCT02505750) which randomises patients with cT2-3a-b, cN0-1, M0 to EBCRT (45 Gy in 25 fractions over 5 weeks with oral capecitabine 825 mg/m2 ) followed by EBRT boost (9 Gy in 5 fractions over 5 days) versus EBCRT followed by CXB boost (90 Gy in 3 fractions over 4 weeks). Patients were assessed at 14, 20 and 24 weeks from the start of treatment. Watch and wait management was adopted for patients who achieved a clinical complete response (cCR) at 24 weeks following treatment. Either local excision (LE) or TME surgery was offered for residual disease or local regrowth, according to patient and surgeon preference. Surgical morbidity and mortality were recorded prospectively. RESULTS: Between July 2015 and June 2020, 148 patients were randomised of which 141 were evaluable in March 2022. At median follow-up of 38.2 months (range: 34.2-42.5), surgery was performed for 66 (47%) patients. A total of 27 (20%) patients had local excision and 39 (29%) had TME surgery, 22/39 (56%) underwent anterior resection and 17/39 (44%) underwent abdominoperineal excision of the rectum. The R0 resection rate was 87%. There were no deaths, and six patients (15%) had Clavien-Dindo IIIb complications. Whilst there was a statistically significant decrease in the TME rate following CXB boost (HR 0.38, 95% CI: 0.19-0.74, p = 0.00419) there was no difference in surgical outcomes between patients who received EBRT and CXB boost. CONCLUSION: Dose escalation can facilitate nonsurgical treatment for cT2-3 rectal cancer patients who are fit but wish to avoid TME surgery and stoma. If TME surgery is required, then it can be performed safely and effectively.

Neoadjuvant chemoradiotherapy with radiation dose escalation with contact x-ray brachytherapy boost or external beam radiotherapy boost for organ preservation in early cT2-cT3 rectal adenocarcinoma (OPERA): a phase 3, randomised controlled trial.

BACKGROUND: Organ preservation after reaching clinical complete response on neoadjuvant therapy is gaining interest for rectal cancers, although the role of radiation dose escalation is still not known. We aimed to determine whether a contact x-ray brachytherapy boost, following or preceding neoadjuvant chemoradiotherapy, increases the probability of 3-year organ preservation for patients with early rectal cancers. METHODS: OPERA was a multicentre, open-label, phase 3 randomised controlled trial done at 17 cancer centres that included operable patients, aged 18 years or older, with cT2, cT3a, or cT3b adenocarcinoma of low-mid rectum, tumours of less than 5 cm in diameter, and cN0 or cN1 smaller than 8 mm. All patients received neoadjuvant chemoradiotherapy and 45 Gy external beam radiotherapy in 25 fractions over 5 weeks with concurrent oral capecitabine (825 mg/m2 twice a day). Patients were randomly assigned (1:1) to receive a boost of external beam radiotherapy at 9 Gy in five fractions (group A) or a boost with contact x-ray brachytherapy (90 Gy in three fractions; group B). Randomisation was done centrally using an independent web-based system and stratified by trial centre, tumour classification (cT2 vs cT3a or cT3b), tumour distance from rectum (<6 cm from anal verge vs ≥6 cm), and tumour diameter (<3 cm vs ≥3 cm). Treatment in group B was stratified by tumour diameter, with the contact x-ray brachytherapy boost given before neoadjuvant chemoradiotherapy in patients with tumours smaller than 3 cm. The primary outcome was organ preservation at 3 years, analysed in the modified intention-to-treat population. This study was registered with ClinicalTrials.gov, NCT02505750, and is ongoing. FINDINGS: Between June 14, 2015, and June 26, 2020, 148 patients were assessed for eligibility and were randomly assigned to group A (n=74) or group B (n=74). Seven patients withdrew their consent (five in group A and two in group B). 141 patients were included in the primary efficacy analysis, including 69 assigned to group A (29 with tumours <3 cm in diameter and 40 with tumours ≥3 cm) and 72 assigned to group B (32 with tumours <3 cm and 40 with tumours ≥3 cm). After a median follow-up of 38·2 months (IQR 34·2-42·5), the 3-year organ preservation rate was 59% (95% CI 48-72) in group A versus 81% (72-91) in group B (hazard ratio [HR] 0·36, 95% CI 0·19-0·70; p=0·0026). For patients with tumours less than 3 cm in diameter, 3-year organ preservation rates were 63% (95% CI 47-84) in group A versus 97% (91-100) in group B (HR 0·07, 95% CI 0·01-0·57; p=0·012). For patients with tumours of 3 cm or larger, 3-year organ preservation rates were 55% (95% CI 41-74) in group A versus 68% (54-85) in group B (HR 0·54, 95% CI 0·26-1·10; p=0·11). 21 (30%) patients in group A and 30 (42%) in group B had an early grade 2-3 adverse event (p=1·0). The most common early grade 2-3 adverse events were proctitis (four [6%] in group A, nine [13%] in group B) and radiation dermatitis (seven [10%] in group A, two [3%] in group B). The main late side-effect was grade 1-2 rectal bleeding due to telangiectasia, which was more frequent in group B (37 [63%] of 59) than in group A (five [12%] of 43; p<0·0001) and subsided after 3 years. INTERPRETATION: Neoadjuvant chemoradiotherapy with a contact x-ray brachytherapy boost significantly improved the 3-year organ preservation rate, particularly for patients with tumours smaller than 3 cm who were treated with contact x-ray brachytherapy first, compared with neoadjuvant chemoradiotherapy with a boost via external beam radiotherapy. This approach could be discussed and offered to operable patients with early cT2-cT3 disease who are keen to avoid surgery and seek organ preservation. FUNDING: The French Programme Hospitalier de Recherche Cinique.

Planned organ preservation for elderly patients with rectal cancer using short course radiotherapy and a contact brachytherapy boost-an International multi-institution analysis.

Background and purpose: The use of external beam radiotherapy (EBRT) and contact X-Ray brachytherapy (CXB) is emerging as an effective alternative in patients with early stage rectal cancer with the intent of organ preservation (OP). Short course radiotherapy (SCRT) is an alternative EBRT schedule for patients not fit for chemotherapy or for longer courses of EBRT. There are no multicentre studies that have reported on the outcomes of SCRT with a CXB boost, therefore we present these from patients from centres from the UK and Sweden. Materials and methods: From the Guildford Colorectal Database or local databases, 258 patients who underwent SCRT and CXB with the intent of OP from five centres treated between 2007 and 2019 were identified. Response and survival data was analysed and presented. Results: With a median age of 81, 226 patients were treated with radiotherapy alone (RTA) and 32 immediately after local excision (ILE). Median follow-up was 24 months. 70% and 97% of patients in the RTA and ILE groups respectively had a complete clinical response (cCR) after SCRT with CXB. Of those, local relapse was seen in 16% of the RTA and 3% of the ILE group. Median survival was 40 months after CXB in the RTA and 52 months in the ILE group. 94% of patients remained stoma-free to the point of latest follow-up. Conclusion: This data suggests that CXB when combined with SCRT, in a mainly elderly and comorbid population, provides good palliation with stoma-avoidance. Oncological outcomes compare with previously published work. A greater focus is required on quality of life outcomes after OP.

A multi-centre analysis of adjuvant contact X-ray brachytherapy (CXB) in rectal cancer patients treated with local excision - Preliminary results of the CONTEM1 study.

INTRODUCTION: Early rectal cancers are increasingly diagnosed through screening programmes and are often treated using local excision (LE). In the case of adverse pathological features completion total mesorectal excision surgery (TME) is the standard recommendation. The morbidity and mortality risks of TME have stimulated the use of adjunctive treatments following LE to achieve organ preservation. MATERIAL AND METHODS: Patients treated with adjuvant CXB following local excision between 2004 and 2017 in three centres were identified (Clatterbridge, Hull, Nice). All patients had adverse pathological features including: lymphovacular invasion, Sm2-3 Kikuchi level, tumour budding, pT2, positive resection margins (R1). CXB was performed with the Papillon50 tm machine to a dose of 40-60 Gy in 2 or 3 fractions over 2-4 weeks preceding/following external beam chemo/radiotherapy. Kaplan Meier survival estimates were used for outcomes measures. RESULTS: 194 patients were identified. Median age was 70 years. pT staging was: pT1:143, pT2:45, pT3:6. CXB alone was given in 24 pts and combined with EBRT in 170. Median follow-up time was 77 months (range 7-122 months). Local relapse rate was 8% and distant metastases 9%. Organ preservation was achieved in 95%. 6 year local recurrence free and overall survival was 91% and 81% respectively. Cancer specific survival was 97%. No treatment related mortality was seen. CONCLUSION: This large multi-centre cohort study using adjuvant CXB following local excision suggests excellent oncological outcomes for these patients without completion TME. This treatment approach can be considered as an alternative for selective patients compliant with long term follow up.

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.

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.

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.