Is the delayed surgery after neoadjuvant chemoradiation beneficial for locally advanced rectal cancer?

BACKGROUND: Neoadjuvant treatment with radiotherapy and chemotherapy is the preferred regimen for locally advanced rectal cancer, aiming to increase resectability and decrease local recurrence. AIM: To evaluate the benefits of delayed surgery after neoadjuvant chemoradiation in advanced rectal cancer regarding aspects of tumor response, survival and its deleterious effects. METHODS: Were treated 106 patients consecutively with locally advanced rectal adenocarcinoma. Neoadjuvant chemoradiation with a dose of 50.4 Gy (28 fractions), 5-fluoracil and leucovorin was given. Surgery was scheduled within five to six weeks. Patients who returned later than six weeks for the scheduled surgery were grouped into the delayed group and variables such as the downstaging rate, complete response, surgical time, blood transfusion, local recurrence, distant metastasis and survival were correlated with the remaining patients in order to determine the benefits of the delayed surgery. RESULTS: Complete tumor response was found in 15 patients (T0=15/106 - 14.2%). Partial response was achieved in 38 patients (34.9%), while one patient had pT0N2 staging. The mean follow-up was 35.6 weeks for the six weeks group, and 32.2 weeks for the delayed group. There were no significant differences between the two groups in terms of downstaging, complete tumor response, surgical time, blood transfusion and early post-operative complications. Although delayed surgery didn't have a significant difference regarding the local recurrence (p=0.1468), it showed a strong tendency in the delayed group of having a lower risk of distant metastasis (p=0.0520). CONCLUSION: Delayed surgery after chemoradiation offered no clear benefits in terms of complete tumor response or downstaging. Predictive molecular factors should be investigated in the future for the proper selection of patients who will benefit from chemoradiation.