The prognostic impact of CD3, CD8, FoxP3, and IL17 tumor-infiltrating immune cells in periampullary cancer differs by morphological type and adjuvant chemotherapy.

Abstract

53 Background: The prognostic impact of tumor-infiltrating T lymphocytes has been evaluated in periampullary carcinoma, but previous studies have not taken into consideration the different morphological subtypes of cancers derived from the periampullary region. Herein, we investigated the prognostic impact and distribution of tumor-infiltrating CD3+, CD8+, FoxP3+ T lymphocytes as well as IL-17+cells in periampullary adenocarcinoma, with particular reference to morpohological subtyoe. Methods: Counts of CD3+, CD8+, FoxP3+ T lymphocytes, and IL-17+cells were assessed using immunohistochemistry on tissue microarrays with tumors from a consecutive retrospective cohort of 175 patients with resected periampullary adenocarcinoma; 110 of pancreatobiliary type (PB-type) and 65 of I intestinal type (I-type). Results: Distribution of all evaluated immune cells differed significantly between PB- and I-type tumors. In I-type tumors, the ratios of IL-17+/FoxP3+ and IL-17+/CD3+ were independent factors of poor prognosis. Notably, the unfavorable prognostic impact of IL-17+ was only evident in cases that had not received adjuvant chemotherapy. In PB-type tumors, CD3+was an independent marker of good prognosis. Conclusions: The results from this study highlight that the composition and prognostic importance of various subsets of infiltrating immune cells in periampullary adenocarcinoma differ by morphological subtype, and potentially by adjuvant chemotherapy.