Clinical impact of tumour-infiltrating B-cells in periampullary adenocarcinoma in relation to adjuvant chemotherapy.

Abstract

330 Background: The prognostic significance of tumour-infiltrating lymphocytes of the B lineage in solid cancers has only recently begun to receive attention. Herein, we explored the relationship between B cell and plasma cell density and survival in patients with periampullary adenocarcinoma, including pancreatic cancer, with particular reference to morphological type. Methods: Immunohistochemistry was applied to quantify the abundance of B cells (CD20+), and plasma cells (CD138+) in tissue microarrays with tumours from a retrospective consecutive cohort of 175 patients who had undergone pancreaticoduodenectomy for periampullary adenocarcinoma. Cox regression was applied to calculate univariable and multivariable hazard ratios (HR) for recurrence and death within five years up until March 2017. Multivariable HRs were adjusted for established clinical parameters. Results: High CD20+ cell density was an independent prognostic factor for a prolonged overall survival in both intestinal-type (HR 0.32; 95% CI 0.12-0.86) and pancreatobiliary-type (HR 0.38; 95% CI 0.23-0.66) tumours. CD138+ was an independent prognostic factor in pancreatobiliary-type tumours (HR 0.51; 95% CI 0.32-0.82) only. A significant positive interaction was seen between adjuvant chemotherapy and CD20+ cells in relation to OS for PB-type tumours (pinteraction= 0.027). Conclusions: These results demonstrate that dense infiltration into the tumour by cells of the B lymphocyte lineage confers an improved prognosis in periampullary adenocarcinoma including pancreatic cancer. The impact of B cells in the local anti-tumour response is gradually being unravelled, and their potential influence on adjuvant chemotherapy response in the more aggressive pancreatobiliary-type tumours may be clinically relevant and merits further study.