207_Combined course Presentations

Colostomy-free survival

Definition Time from randomisation to colostomy formation (in ITT population) Pros • Easy to define • Not affected by crossover or subsequent treatment (eg checkpoint inhibitors) Cons • ? Measure of direct benefit • Initial colostomy can be reversed but often not reversed • Colostomy can be formed both for recurrence and late effects Censor bias – if imbalanced withdrawal of patients who are censored prior to colostomy