3-year disease-free survival in patients with rectal cancer following an opportunistic watch-and-wait approach—results from the Swedish WoW study
Lidija Mijaljevic, Eva Angenete, Najia Azhar, Abbas Chabok, Joakim Folkesson, Anders Gerdin, Rode Grönkvist, Peter Matthiessen, Daniel Rydbeck, Per J Nilsson, Anna MartlingAbstract
Introduction
Organ preserving strategies in the management of rectal cancer are emerging. Neoadjuvant treatment can induce a clinical complete response (cCR), enabling an opportunistic watch-and-wait approach. The Watch-and-Wait (WoW) study, a national prospective observational study of patients with cCR after neoadjuvant treatment, was initiated in Sweden in 2017.The primary endpoint was three-year disease-free survival (DFS). Secondary endpoints included regrowth rate, distant metastasis (DM) rate and outcomes after salvage surgery for regrowth.
Methods
Patients with rectal adenocarcinoma who obtained cCR after neoadjuvant treatment were included in a structured watch-and-wait program, with prespecified follow-up intervals to detect regrowth or DM. Inclusion and follow-up were performed at eight dedicated centers. Neoadjuvant therapy was according to national guidelines. Patients with regrowth were advised resection surgery.
Results
A total of 211 patients with cCR were included between January 2017 and February 2023. Three-year DFS was 91% (191/211) and regrowth rate was 27% (57/211). Fifty-five out of 57 (96%) patients with regrowth underwent salvage surgery with R0 rate of 96% (53/55). Distant metastases occurred in 13/211 (6%) patients overall; 4/150 (3%) among those with sustained cCR and 9/57 (16%) among patients who developed regrowth.
Discussion
Patients with a cCR following neoadjuvant treatment for rectal cancer had an excellent three-year DFS after an opportunistic watch-and-wait approach. Regrowth rates were similar to previous studies, and successful salvage surgery was performed in nearly all patients. The study supports the safe adoption of opportunistic watch-and-wait for selected patients in a centralized Swedish setting.