CD274 (PD-L1), CDKN2A (p16), TP53, and EGFR immunohistochemical profile in primary, recurrent and metastatic vulvar cancer.

Vulvar squamous cell carcinoma can be divided by human papillomaviruses (HPV) status into two distinct clinicopathological and molecular entities. New agents targeting the tumor surface expression of programmed cell death-1/programmed cell death-ligand-1 are becoming a therapeutic option in an increasing number of carcinomas. We evaluate CD274 (PD-L1), CDKN2A (p16), tumor protein p53 (TP53), and epidermal growth factor receptor (EGFR) immunoexpression in primary tumors, recurrences and lymph node metastases and its correlations with prognosis and HPV status. We report 93 cases of vulvar squamous cell carcinoma diagnosed between 2002 and 2016 with the description of their clinicopathological features and prognosis data. Immunohistochemistry for CD274, CDKN2A, TP53, and EGFR was performed on tissue microarrays collecting from primary tumor, recurrences and lymph node metastasis. Kaplan-Meier estimator and multivariable Cox regression analysis controlling for FIGO stage and age were used. Patients who underwent surgery had a superior overall survival (HR = 0.51, 95% CI = 0.26-0.99 p = 0.04). Lymph node metastasis size ≥5 mm was associated with an inferior overall survival (HR = 1.88, 95% CI = 1.22-2.92 p = 0.004). CDKN2A expression was correlated with an inferior rate of recurrent disease (p = 0.02). In high-risk HPV DNA+ vulvar squamous cell carcinomas patients with CDKN2A- carcinomas showed a significantly worse overall survival than women with CDKN2A+ tumors (56% vs.100%, p = 0.003). TP53 expression was associated with an increased rate of recurrent disease (p = 0.0005). CD274 expression was associated with lymph node metastasis (p = 0.04). In 16 patients the CD274, CDKN2A, TP53, and EGFR expression changed between primary tumors, recurrences and lymph node metastases during tumor progression. In conclusion, a significant percentage of vulvar squamous cell carcinoma has a heterogeneous biomarker expression during tumor progression. We highlight the importance of some of these markers to be used as prognostic biomarkers. This data brings new light to future treatment using targeted therapy to EGFR or CD274 to include retesting such biomarkers in recurrence and lymph nodes metastases.