Is routine use of adjuvant chemotherapy for rectal cancer with complete pathological response justified?

BACKGROUND: Patients with locally advanced rectal cancer (LARC) receiving neoadjuvant chemoradiation (nCRT) can have a complete pathologic response (pCR), and are given postoperative adjuvant chemotherapy (ACT).

METHODS: A prospectively maintained outcomes database was queried for patients who had pCR to nCRT for LARC from 2000 to 2012. Local recurrence and survival were analyzed according to whether patients received ACT.

RESULTS: We identified 139 patients and excluded 9 due to lack of follow-up. Mean age was 58.9 ± 11.8 years. 83 patients (63.8%) did not receive ACT (Group A) and 47 (36.2%) did (Group B). Mean follow-up was 5.7 ± 3 and 5.6 ± 3.5 years for Groups A and B respectively (p = 0.51). Groups were comparable in age, gender, tumor differentiation, and clinical staging. There were no differences in oncological outcomes.

CONCLUSION: Avoiding routine use of ACT in patients with a pCR may be considered. Further justification of this approach warrants prospective randomized studies.