Low rectal cancer treatment strategies: a cohort study assessing watch and wait.

Purpose: Treatment strategies for low rectal cancer have been evolving toward achieving less treatment morbidity with the same oncological success—we aimed to assess the results of the new watch and wait (W&W) strategy in our cohort. Methods: A tertiary care cohort study was conducted. New patients with rectal adenocarcinoma up to 6 cm from the anal margin, cM0, locally staged higher than cT1N0, evaluated between November 2014 and October 2018, were included. All 93 patients received neoadjuvant radiotherapy ± chemotherapy. Re-evaluation was planned 8–12 weeks after the end of treatment. Patients showing clinical complete response (cCR) were given the choice of either to proceed to surgery or to enter W&W. Results: Of the 93 patients, 82.8% were re-evaluated and 20.8% had cCR. Patients in clinical stages II/III were significantly less likely to achieve cCR than those in stage I (p = 0.017). After a mean follow-up of 17.44 months, there were 4 regrowths in the 16 patients under W&W, all submitted to R0 surgery, ypN0; there were no deaths or local recurrences; one patient with regrowth had distant recurrence. Sixty patients underwent direct surgery after a mean follow-up of 16.23 months; 3 patients had local and distant recurrences; 7 others had only distant recurrences; there were 8 deaths. There were no statistically significant differences between patients under W&W and patients who underwent direct surgery regarding local or distant recurrences, or death (p > 0.9; p = 0.44; p = 0.19, respectively). Conclusion: The W&W strategy for low rectal cancer achieved the same oncological outcomes as the traditional strategy while sparing some patients from surgery. [ABSTRACT FROM AUTHOR]