Abstract 1712
Background
Neoadjuvant chemoradiation therapy improves local control, may lead to significant tumor regression and even complete pathological response. We compared patients managed by watch and wait approach and those submitted to surgery with pathological complete response.
Methods
We included patients with rectal adenocarcinoma who had received neoadjuvant long-course chemoradiation therapy (45-50.4 Gy in 25-28 daily fractions with concurrent fluoropyrimidine-based chemotherapy) between July 2003 and December 2012. After, we compared outcomes between two groups: 1) 39 patients managed with watch and wait (WW) approach after clinical complete response; 2) 68 patients submitted to surgery and had pathological complete response (pCR). The primary endpoint was relapse-free survival (RFS).
Results
The median age was 63.5years of age (43-81y) for WW and 60 (29-86y) for pCR. After median follow up of 73 months, of 39 patients managed by watch and wait, 8 (20%) patients had local relapse, 4 (10%) patients had distant relapse, and 3 (7.5%) patients had both and of 68 patients with pCR, 4 (5.8%) patients had local relapse, 5 (7.3%) patients had distant relapse, and 3 (4.4%) patients had both. Salvage surgery was possible in 5 (62.5%) patients after local relapse and 1 (33%) patient after local and distant relapse in WW group, but was not possible in any patient in pCR group. Twenty-five (62.5%) patients have sustained complete clinical response without any surgery in WW group. Local relapse was 3 times higher in WW group (OR 3 – CI:1.09-8.69) and distant relapse were equal (OR: 1.3 – CI:0.43-4.26). The 3- and 5-year RFS was 84.8% and 75.1%, respectively, and was significant better in pCR than WW (HR: 2.46 CI: 1.13-5.49 – p: 0.02). The 3- and 5-year OS was 89.3% and 79.1%, respectively, and was similar in both groups (HR: 1.43 CI: 0.64-3.27 – p: 0.36). Permanent colostomy was 2.6 higher in pCR group (CI:1.02-6.69).
Conclusions
The watch and wait approach had worse RFS without impact on overall survival. Radical rectal surgery was avoided in 62.5% of patients selected and salvage surgery was possible in 62.5% of patients who had local relapse in WW group. The odds of permanent colostomy were 2.6 higher in pCR group.
Clinical trial identification
Legal entity responsible for the study
INCA - Instituto Nacional de Cancer
Funding
None
Disclosure
All authors have declared no conflicts of interest.