MIS1-1 - Lymphovascular Invasion is a Significant Prognosticator in Rectal Cancer Patients who Receive Preoperative Chemoradiotherapy Followed by Total Mesorectal Excision

Abstract

ABSTRACT Background This study was designed to identify the significance of lymphovascular invasion as a prognosticator for tumor recurrence and survival in rectal cancer patients treated with preoperative chemoradiotherapy (CRT) and total mesorectal excision (TME). Methods Between January 2003 and October 2010, the study included 328 patients with primary rectal cancer who had received preoperative CRT followed by TME. We analyzed the clinicopathologic factors that may be associated with survival, such as age, gender, carcinoembryonic antigen (CEA) value, pathologic T and N stage, tumor response, histologic grade, lymphovascular invasion (LVI), and perineural invasion. Results Higher pathologic T and N stage, poor tumorresponse, high-grade histology, and positive LVI were adverse prognostic factors for both disease-free survival (DFS) and overall survival (OS) on the multivariate analysis. Perineural invasion was a significant adverse prognostic factor affecting DFS (P = 0.046) but not OS (P = 0.08). Increased T and N stage and distant recurrence, but not local recurrence, were significant factors associated with LVI. The LVI-negative group had a higher DFS (71.4 versus 56.2%, P = 0.012) and OS rate (86.7 versus 63.4%, P = 0.020) at 5 years than the LVI-positive group did. Conclusions Positive LVI had a negative impact on survivalin patients with rectal cancer who received preoperative CRT and TME and is significantly associated with an increased chance of distant recurrence. Based on this finding, more tailored adjuvant chemotherapy is warranted for advanced rectal cancer patients with LVI to reduce the distant dissemination of tumor.