Pathologic Response to Preoperative Therapy as a Novel Prognosticator for Ampullary and Duodenal Adenocarcinoma

Background. The prognostic impact of pathologic response to preoperative therapy on patients with duodenal adenocarcinoma (DA) and ampullary adenocarcinoma (AMPA) has not been established. Methods. A retrospective review of 266 patients who underwent curative resection for DA (n = 97) or AMPA (n = 169) during 1993-2015 was performed. For patients who underwent preoperative therapy, the pathologic response was systematically evaluated and classified as major (0-49% of viable residual tumor cells) or minor (>= 50% of viable residual tumor cells). Uni- and multivariable analyses were performed to identify predictors of pathologic response and disease-specific survival (DSS). Results. For the 79 patients treated with preoperative therapy (DA: n = 34; AMPA: n = 45), concomitant use of radiation (80%, 67/79) was the sole independent predictor of major pathologic response (odds ratio [OR] 8.17; 95% confidence interval [CI] 1.85-58.2; P = 0.005). The patients with major pathologic response had a better 5-year DSS rate than the patients with minor pathologic response (DA: 65 vs 25%; P = 0.028; AMPA: 85 vs 43%; P = 0.016). In the multivariable analysis of DSS for the 79 patients who underwent preoperative therapy, major pathologic response was the sole predictor of improved DSS (hazard ratio [HR] 2.88; 95% CI 1.41-5.98; P = 0.004). In the multivariable analysis of DSS for the entire cohort, pathologic stage 2 or lower was the sole predictor of better DSS. Conclusion. The major pathologic response to preoperative therapy predicted improved DSS after resection of DA and AMPA and might represent a new prognosticator after resection of DA and AMPA.