Watch and Wait in practice: Adherence to surveillance after nonoperative management for rectal cancer

Surveillance after neoadjuvant therapy and complete clinical response, known as "Watch and Wait," is an accepted treatment approach for locally advanced rectal cancer. Watch and Wait replaces surgical resection with rigorous surveillance for early identification of regrowth. However, there are scant data on adherence to surveillance. This study aimed to assess the adherence to Watch and Wait and the receipt of optimal surveillance.

A multicenter cohort of patients diagnosed with rectal adenocarcinoma from 2021to 2022 was retrospectively reviewed. Patients who underwent Watch and Wait after neoadjuvant therapy and complete clinical response were included. The primary endpoint was receipt of National Comprehensive Cancer Network guideline-based surveillance. Patients were stratified by receipt of optimal surveillance, defined as completion of all required imaging and endoscopic surveillance elements during their analyzed time within Watch and Wait. Variables were compared with Fisher exact or Mann-Whitney U tests. The Kaplan-Meier method was used for time-to-event analysis.

Fifty-three patients underwent Watch and Wait. Of these, 33 (62%) had optimal surveillance, with a median follow-up of 17 months. Those receiving optimal surveillance were younger (median age 54 vs 63 years, P = .04), and there were no differences by socioeconomic factors. On Kaplan-Meier analysis, the most common missed events leading to suboptimal surveillance were an endoscopic or imaging examination before 9 months and a full colonoscopy before 18 months.

Of patients who underwent Watch and Wait, 62% received optimal surveillance. Patients were at greatest risk for missing the first required endoscopic or imaging surveillance and the first full colonoscopy. Patients undergoing nonoperative management are most likely to miss surveillance in the critical first year, during which regrowth occurs.