RETROSPECTIVE ANALYSIS OF THE PREDICTORS OF OUTCOME FOLLOWING LOCAL EXCISION FOR T1 RECTAL ADENOCARCINOMA

Objective: Early-stage cancers may allow for less radical approaches such as local excision which preserve quality of life without compromising oncologic outcomes. We examined outcomes of patients with early-stage rectal adenocarcinoma treated with Local excision (LE). Patients and Methods: We queried the NCDB for patients with pT1N0M0 rectal adenocarcinoma treated with local excision alone. Multivariable Cox regression was used to identify predictors of overall survival (OS). Results: We identified 887 patients eligible for analysis across 2010-2014. The median tumor size was 1.5 cm (IQ range: 0.9-2.5 cm). A minority of patients had grade 3 tumors (5%), lymphovascular invasion - LVI (8%), or perineural invasion PNI (<1%). Median follow up was 36 months (1-83). Predictors of worse survival included: size >4 cm, age >67, higher comorbidity score, and presence of LVI. On Kaplan Meier analysis, 5-year OS was 75% vs. 74% for patients without and with LVI, respectively (p-value=0.0115). In terms of size, the 5-year OS rates were 74% for size <4 cm vs. 51% size >4 cm (p-value=0.0138). Conclusions: The study demonstrates excellent survival outcomes in patients with early-stage rectal adenocarcinoma treated with LE alone. LVI remains a predictor of outcome, while grade and PNI were not significant.