Tumour- and treatment-related colostomy rates following Mitomycin or Cisplatin chemoradiation with or without maintenance chemotherapy in squamous cell carcinoma of the anus in the ACT II trial
Mené sur 940 patients atteints d'un carcinome épidermoïde de l'anus (durée médiane de suivi : 5,1 ans ), cet essai évalue l'effet d'un traitement, combinant ou non une chimioradiothérapie par 5-fluorouracile-cisplatine ou 5-fluorouracile-mitomycine et une chimiothérapie d'entretien, sur la survie sans progression et la survie sans colostomie, puis identifie les facteurs prédictifs associés à la survie sans colostomie
Background : Squamous cell carcinoma of the anus (SCCA) is highly sensitive to chemoradiation which achieves good loco-regional control and preserves anal function. However some patients require permanent stoma formation either as a result of surgery on relapse, poor anal function or treatment-related symptoms. Our aim was to determine patient, tumor and treatment-related colostomy rates following chemoradiation (CRT) and maintenance chemotherapy in the ACT II trial. Patients and methods : The ACT II trial recruited 940 patients comparing 5FU-based CRT using cisplatin (CisP) or mitomycin (MMC) with or without additional maintenance chemotherapy. We investigated the association between colostomy-free survival (CFS) and progression-free survival (PFS) with age, gender, T-stage, N-stage, treatment and baseline haemoglobin. Results : Median follow-up was 5.1 years (n=884 evaluable/940); tumour site canal (84%), margin (14%); stage T1/T2 (52%), T3/T4 (46%); N+(32%), N0 (62%). 20/118 (17%) colostomies fashioned prior to CRT were reversed within 8 months. 112 patients had a post-treatment colostomy due to persistent disease (98) or morbidity (14). 52% (61/118) of all pre-treatment colostomies were never reversed. The 5-year CFS rates were 68% MMC/Maint, 70% CisP/Maint, 68% MMC/No-maint and 65% CisP/No-maint. CRT with CisP did not improve CFS when compared to MMC (HR: 1.04, 95% confidence interval: 0.82-1.31, p=0.74). The 5-year CFS rates were higher for T1/T2 (79%) than T3/T4 (54%) tumours and higher for node-negative (72%) than node-positive (60%) patients. Significant predictors of CFS were gender, T-stage and haemoglobin while treatment factors had no impact on outcome. Similar associations were found between PFS and tumour/treatment-related factors. Conclusions : The majority (52%) of pre-treatment colostomies were never reversed. Neither CRT with 5FU/CisP nor maintenance chemotherapy impacted on CFS. The low risk of colostomy for late effects (1.7%) is likely to be associated with the modest total radiotherapy dose. The predictive factors for CFS were T-stage, gender and baseline haemoglobin.
Annals of Oncology 2014