An interval >7 weeks between neoadjuvant therapy and surgery improves pathologic complete response and disease-free survival in patients with locally advanced rectal cancer

Background: We assessed whether the time interval between neoadjuvant therapy and surgery affects the operative and postoperative morbidity and mortality, the pathologic complete response (pCR) rate, and disease recurrence in locally advanced rectal cancer. Methods: One-hundred and thirty-two patients with locally advanced low- and mid-rectal cancer underwent neoadjuvant chemoradiation followed by radical resection (October 2000 to December 2006). Data on the neoadjuvant regime, neoadjuvant-surgery interval, final pathology, type of operation, operative time, intraoperative blood transfusions, postoperative complications, length of hospital stay, disease recurrence, and mortality were reviewed. The patients were divided into two groups according to the neoadjuvant-surgery interval: > 7 weeks (group A, n = 48), and > 7 weeks (group B, n = 84). Results: The groups were demographically comparable except for the group A patients being younger at operation. The median interval between chemoradiation and surgery was 56 days (range 13-173 days). Thirty-seven patients (28%) had a pCR and near pCR. Fifty three patients (40%) had complications. There was no in-hospital mortality. Surgery type, operative time, number of intraoperative blood transfusions, postoperative complications, and length of hospitalization were not influenced by the interval length. The pCR and near pCR rates were higher with longer interval: 17% in group A, 35% in group B (P = 0.03). Patients operated at an interval > 7 weeks had significantly better disease-free survival (P = 0.05). Conclusions: A neoadjuvant-surgery interval > 7 weeks was associated with higher rates of pCR and near pCR, decreased recurrence and improved disease-free survival.