Preoperative Chemoradiation in Locally Advanced Rectal Cancer: Efficacy and Safety.

Background: Preoperative chemoradiation (CRT) is considered the standard of care in the management of stage II/III rectal cancer. The aim of this retrospective study was to assess the efficacy and safety of preoperative CRT in our patient cohort with locally advanced rectal adenocarcinoma.

Methods: Forty patients with cT3-4N0-2M0 adenocarcinoma of the lower (n = 26) and mid/upper (n = 14) rectum were enrolled in this study between 2001 and 2012. Radiotherapy (RT) was given to the pelvis. The median prescribed dose was 45 Gy (daily dose, 1.8 - 2.0 Gy). All patients received chemotherapy concurrently with RT and underwent surgery 6 - 8 weeks after CRT. Low anterior resection (LAR) was achieved in 21 patients. Total mesorectal excision (TME) was performed in 24 patients.

Results: Tumor downstaging (expressed as TN downstaging) was observed in 15 patients (38%); a pathological complete response (pCR) was pathologically confirmed in six of them. In nine out of the 26 (23%) patients with low lying tumors, sphincter preservation (SP) was possible. SP was also possible in all but one patient (13%) who achieved a pCR. In three out of 15 patients (8%) with preoperative sphincter infiltration, SP was achieved. With a median follow-up of 58 months, the 4-year local control (LC), distant metastases-free survival (DMFS), disease-free survival (DFS) and overall survival (OS) rates were 89.7%, 86.9%, 79.5% and 81.2%, respectively. The pretreatment tumor size was predictive of response to preoperative CRT. The response to preoperative CRT did show a significant impact on DFS and on OS. TME resulted in a statistically significant increased DFS rate. No grade 3/4 acute toxicity was reported. Three patients developed grade 3 late side effects.

Conclusion: Preoperative CRT demonstrates encouraging rates of disease control and facilitates complete resection and SP in advanced rectal cancer with acceptable late toxicity.