Comparison of the clinical efficacy of a new prognostic stratification for duodenal adenocarcinoma with that of TNM staging: The importance of T status with regard to the prognosis.

Abstract

Although the current staging system and therapeutic strategy for duodenal adenocarcinoma (DA) focus on the N status, their validity has not been clarified. In this study, we evaluated the prognostic factors of DA and reviewed the current staging system. We included 105 patients who underwent surgical resection of DA in our department between September 2006 and October 2020. Patients with localised disease other than an early tumour (pT1a) were classified into the advanced group, and prognostic factors were compared with those for the Union for International Cancer Control (UICC) classification, 8th edition. The 5-year overall survival (OS) rate in the advanced group (n=55) was 73%. Multivariate analysis revealed that pT4 and pN2 statuses were independent prognostic factors for OS. The prognosis was stratified based on the pT4 and pN2 statuses, whereas the survival curves for patients with pStage II (pN0) and pStage IIIA (pN1) DA overlapped on staging according to the UICC classification. The new classification indicated a favourable prognosis for patients classified as pT1-3N1 stage IIIA (5-year OS, 86%), whereas the prognosis of patients with pT4N0-1 DA was similar to those classified as pT1-3N2 stage IIIB. Patients with pT4N2 DA had a similar prognosis (5-year OS, 24%) as those with metastases, and 75% of these patients showed distant metastasis within one year after surgery. Both T and N statuses affect the prognosis of DA. Patients with pT4N2 DA may require intensive adjuvant chemotherapy. (238 words).