“Watch and wait” strategy (active dynamic follow-up) in the management of rectal cancer patients with a complete clinical response

Background. Currently available chemoradiotherapy regimens for distal rectal cancer often ensure complete regression of the tumor and lymph node lesions. Therefore, patients with a complete clinical response can be managed with a “watch and wait” (ww) strategy.Objective: to evaluate 2-year overall and progression-free survival in patients with local and locally advanced rectal cancer with a complete clinical response who were managed with the ww strategy.Materials and methods. we performed retrospective analysis of treatment outcomes in patients with newly diagnosed, histologically verified, stage II–III, mrT1–2n1–2m0, T3–4n0–2m0 (within 0–10 cm of the anal verge), and mrT2n0m0 (within 0–5 cm of the anal verge) rectal cancer who had demonstrated complete clinical response to chemoradiotherapy. mandard tumor regression grade (TRg1–2) (assessed using magnetic resonance imaging of the pelvis) and palpatory/visual signs of residual tumor (assessed by digital examination and colonoscopy) were the main parameters evaluated. Overall and disease-free survival was analyzed using the Kaplan–meier method.Results. Twenty-seven patients with a complete clinical response were assigned to the ww group. mRI scans of the pelvis demonstrated that 5 patients (18.5 %) had TRg1, whereas 22 patients (81.5 %) had TRg2. T-downstaging after therapy was observed in 21 participants (77.7 %). n-downstaging was registered in all 14 patients (100 %) with regional lymph nodes affected. median follow-up time was 41 months (range: 25–114 months). Two individuals (7.4 %) developed progressive disease. Both of them had lengthy tumors as demonstrated by digital examination, colonoscopy, and magnetic resonance imaging; they immediately underwent radical surgery. The two-year overall and disease-free survival rates were 100 % and 92.6 %, respectively. Conclusion. The ww strategy with active dynamic follow-up is safe for the management of patients with local and locally advanced middle and lower rectal cancer, provided that inclusion/exclusion criteria are adhered to and patients are carefully followed-up in specialized centers.