Long-term Oncologic Outcomes After Neoadjuvant Chemoradiation Followed by Intersphincteric Resection With Coloanal Anastomosis for Locally Advanced Low Rectal Cancer

BACKGROUND: To date only few data have been available relating to the oncologic safety of intersphincteric resection in such advanced tumors. OBJECTIVE: This study aimed to elucidate the oncologic outcomes and clinical factors affecting the long-term survival of patients who underwent preoperative chemoradiotherapy followed by intersphincteric resection for locally advanced rectal cancers. DESIGN: This was a retrospective analysis of prospectively collected departmental data. SETTINGS: The study was conducted at a department of colorectal surgery in a tertiary care teaching hospital between January 2009 and September 2015. PATIENTS: A cohort of 147 consecutive patients with low rectal cancer undergoing intersphincteric resection after preoperative chemoradiotherapy was included. MAIN OUTCOME MEASURES: Kaplan-Meier analyses were used to evaluate the 3-year disease-free survival and local recurrence rates. Logistic regression analyses were used to analyze the influence of tumor response and other prognostic factors on survival outcomes. RESULTS: Median follow-up was 34 months (range, 8-94 mo). The estimated overall 3-year disease-free survival and local recurrence rates were 64.9% and 11.7%. Circumferential resection margin involvement and pathologic T stage (ypT stage) were significant predictors of cancer relapse. The 3-year disease-free survival was 47.4% for patients with ypT3 tumors compared with 82.0% for those with ypT0-2 tumors (p = 0.001). The 3-year disease-free survival was 36.5% for patients with involved circumferential resection margins compared with 69.7% for those with a noninvolved circumferential resection margin (p = 0.003). On multivariate analysis, ypT stage, ymrT stage, and circumferential resection margin status were associated with worse disease-free survival. Clinical T-stage and pathologic distal margin status were not independent factors affecting oncologic outcomes. LIMITATIONS: This study is limited with respect to its retrospective design. CONCLUSIONS: In these patients with locally advanced low rectal cancers, intersphincteric resection after preoperative chemoradiotherapy was associated with acceptable oncologic outcomes. See Video Abstract at http://links.lww.com/DCR/A941.