Treatment outcomes of patients with adenocarcinoma of the uterine cervix after definitive radiotherapy and the prognostic impact of tumor-infiltrating CD8⁺ lymphocytes in pre-treatment biopsy specimens: A multi-institutional retrospective study

The current study aimed to evaluate the outcomes of patients with adenocarcinoma (AC) of the uterine cervix after definitive radiotherapy (RT) and to evaluate prognostic factors, including immunity-related molecules. A total of 71 patients with AC of the uterine cervix from multiple Japanese institutions were retrospectively analysed. Histological subtypes were diagnosed according to the 2014 World Health Organization classification. All patients underwent definitive RT comprising external beam RT and intracavitary brachytherapy with or without concurrent chemotherapy. Immunohistochemical studies were performed to detect the expression of programmed cell death-ligand 1(PD-L1) and CD8. The 5-year locoregional control (LC), overall survival (OS) and progression-free survival (PFS) rates for all patients were 61.8, 49.7 and 36.1%, respectively. The LC, OS and PFS rates were not significantly different among the histological subtypes. Membranous PD-L1 expression was not significantly associated with prognosis. Patients with CD8-positive tumor-infiltrating lymphocytes (CD8⁺TILs) in the tumor nests had significantly better OS than patients without CD8⁺TILs in the tumor nests (5-year OS: 53.8 vs 23.8%, P = 0.038). As expected, the International Federation of Gynecology and Obstetrics (FIGO) stage (2008) III-IVA and maximum tumor diameter > 40 mm were significantly associated with worse prognosis. In summary, the presence of CD8⁺TILs in the tumor nests has the potential to be an independent favorable prognostic factor for patients with AC of the uterine cervix after definitive RT.