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.