Impact of therapeutic delay in colorectal cancer on overall survival and cancer recurrence – is there a safe timeframe for prehabilitation?

Interest in adoption of a prehabilitation programme in management of colorectal cancer is increasing, but current waiting time targets leave no opening for intervention. Prompt treatment following diagnosis is demanded but defending evidence is lacking. We aimed to investigate the impact of prolonged therapeutic delay on overall and cancer-free survival in patients with primary colorectal cancer. Retrospective analysis was performed in a detailed dataset of patients with primary colorectal cancer who underwent curative surgical treatment between January 2010 and December 2016. Groups were made according to therapeutic delay ≤35 days or >35 days. Endpoints were overall and cancer-free survival, assessed with Kaplan-Meier survival curves, log-rank tests and Cox proportional hazard analyses. A total of 790 patients were included of whom 559 had a colonic tumour and 231 a rectal tumour. Median therapeutic delay was 32 days (IQR 26-43 days). Multivariate analysis showed therapeutic delay >35 days was not associated with poorer overall survival (HR = 1.202, p = 0.249) or earlier cancer recurrence (HR = 1.256, p = 0.212). Similar results were found when stratifying analyses for colonic and rectal cancer, and when defining prolonged delay as >49 days. Prolonged treatment delay does not lead to poorer overall or cancer-free survival in patients with primary colorectal cancer who underwent curative surgical treatment. This allows professionals to push current national waiting time targets in order to adopt a prehabilitation programme without jeopardizing outcomes.