Delaying surgery after neoadjuvant chemoradiotherapy improves prognosis of rectal cancer

AIM To investigate the prognostic effect of a delayed interval between neoadjuvant chemoradiotherapy (CRT) and surgery in locally advanced rectal cancer. METHODS We evaluated 87 patients with locally advanced mid-or distal rectal cancer undergoing total mesorectal excision following an interval period after neoadjuvant CRT at Sisli Hamidiye Etfal Training and Research Hospital, Istanbul between January 2009 and January 2014. Patients were divided into two groups according to the interval before surgery: < 8 wk (group.) and >= 8 wk (group.). Data related to patients, cancer characteristics and pathological examination were collected and analyzed. RESULTS When the distribution of timing between group. (n = 45) and group. (n = 42) was viewed, comparison of interval periods (median +/- SD) of groups showed a significant difference of as 5 +/- 1.28 wk in group. and 10.1 +/- 2.2 wk in group. (P < 0.001). The median follow-up period for all patients was 34.5 (9.9-81) mo. group. had significantly higher rates of pathological complete response (pCR) than group. had (19% vs 8.9%, P = 0.002). Rate of tumor regression grade (TRG) poor response was 44.4% in group. and 9.5% in group. (P < 0.002). A poor pathological response was associated with worse disease-free survival (P = 0.009). The interval time did not show any association with local recurrence (P = 0.79). CONCLUSION Delaying the neoadjuvant CRT-surgery interval may provide nodal down-staging, improve pCR rate, and decrease the rate of TRG poor response.