Prognostic Impact of Ventral Versus Dorsal Tumor Location After Total Mesorectal Excision of Rectal Cancer

Abstract

Background Multidisciplinary treatment of rectal cancer, including neoadjuvant treatment, total mesorectal excision, and adjuvant chemotherapy, have improved oncological outcome. Preoperative radiation therapy is advocated by national and international guidelines in all patients with AJCC stage II and III rectal cancer. Although this treatment reduces local recurrence rates with no effect on overall survival, there are possible short- and long-term side effects of radiation exposure, so patients should be carefully selected for neoadjuvant radiation therapy. Methods We analyzed whether ventral or dorsal tumor location affects local recurrence rates following radical rectal resection. Patients who underwent radical rectal resection for mid or low rectal cancer in our department between October 2001 and December 2013 were included. Prognostic indicators for local recurrence were analyzed using univariate and multivariate analyses. Results Overall, 480 patients met the inclusion criteria. Univariate analysis identified surgical procedure (hazard ratio [HR] 1.9, p \u2009=\u20090.006), ventral tumor location (HR 3.8, p \u2009<\u20090.001), and a pathologic circumferential resection margin (pCRM) (HR 9.3, p \u2009<\u20090.001) as prognostic factors of local recurrence. Multivariate analysis revealed tumor location (HR 3.5, p \u2009<\u20090.001) and pCRM (HR 6.0, p \u2009=\u20090.002) as independent factors for local recurrence. Neoadjuvant treatment of AJCC stage II and III tumors reduced the local recurrence rate at ventral but not at dorsal tumor locations ( p \u2009<\u20090.001). Conclusions Ventral versus dorsal tumor location is an independent prognostic factor for local recurrence. Tumor location may aid in patient selection for neoadjuvant treatment.