The Role of P16, P53, KI-67 and PD-L1 Immunostaining in Primary Vaginal Cancer.

BACKGROUND: To analyze clinical, pathological and immunohistochemical correlates of survival in vaginal cancer patients. METHODS: Retrospective analysis of primary vaginal cancer patients, treated at the Department of Gynecology and Gynecological Oncology of the University Hospital Bonn between 2007 and 2021. RESULTS: The study cohort comprised 22 patients. The median age was 63 years (range: 32-87 years). Squamous cell histology was present in 20 patients. Five-year OS in Stage I, II, III and IV was 100%, 56.25%, 0% and 41.67%, respectively (p = 0.147). Five-year DFS was 100%, 50%, 0% and 20.83%, respectively (p = 0.223). The 5-year OS was significantly reduced in the presence of nodal metastasis (p = 0.004), lymphangiosis (p = 0.009), hemangiosis (p = 0.002) and an age above 64 years (p = 0.029). Positive p 16 staining was associated with significantly improved OS (p = 0.010). Tumoral and immune cell PD-L1 staining was positive in 19 and in 16 patients, respectively, without significant impact on OS; 2 patients with metastastic disease are long-term survivors treated with either bevacizumab or pembrolizumab. CONCLUSION: P16 expression, absence of lymph- or hemangiosis, nodal negative disease and an age below 64 years show improved survival rates in PVC. Tumoral PD-L1 expression as well as PD-L1 expression on immune cells is frequent in PVC, without impacting survival. Within our study cohort, long-term survivors with recurrent PVC are treated with anti-VEGF and immunotherapy.