Analysis of recurrence pattern and survival in locally advanced rectal cancer treated with neoadjuvant chemoradiation and surgery: 25 years of experience.

Abstract

744 Background: The standard treatment for locally advanced rectal cancer (LARC) is neoadjuvant chemoradiation (CRT) followed by total mesorectal excision (TME). Despite the significant reduction (~ 40%) in local recurrence, the overall survival (OS) and disease free survival (DFS) remain stable during last decade. We aimed to study the pattern of recurrence and it’s relationship with clinico-pathological data in 356 patients with LARC treated with CRT and TME in last 25 years. Methods: From a total of 621 patients, 356 with LARC were analyzed. In 55 (15.4%) the tumor was localized in upper third, in 120 (33.7%) in middle third and in 181 (50.8%) in distal third. The median dose of radiotherapy for the 3 groups was between 47.5 - 48.52 Gy. Chemotherapy was based on 5-FU or capecitabine combined with oxaliplatin. Type of surgery, pathological response grade, circumferential resection margin, lymphovascular invasion, colloid response, local recurrence incidence, distal relapse, OS and DFS were analyzed. Results: The median interval between the end of CRT and surgery was 40 days. 52 low anterior resection were carried-out in upper third (94.5%), 112 (93.3%) in middle third and 92 (50.8%) in distal third. Four patients from the middle third (3.3%) underwent abdominoperineal resection and 72 (39.8%) in the distal location. No differences were observed in number of lymphoid nodes, vascular perineural invasion, and pathological response grade. A pathological complete response was assessed in 5 patients (9.1%) in upper third, in 12 (10%) in middle third, as well in 32 (17.7%) in distal third. Median follow-up of 187 months. The 5-10 year DFS for the 3 groups was 75%, 76%, and 69%, and 75%, 71%, and 66% respectively. The local recurrence rate was 3.6%, 4.2%, and 6.1%. The distal recurrence was more frequent in the lung, 10.9%, 16.7%, 23.8%, with tendency to be significant (p<0.007) in distal third. Conclusions: In spite of the good local control with the association of preoperative CRT and TME in treatment of LARC, the development of distant metastases, especially in distal third, gives rise to new therapeutics schemes. Further research is warranted as to the benefits of adjuvant chemotherapy.