Perineural Invasion as a Predictive Biomarker of Groin Metastases and Survival Outcomes in Vulvar Cancer: A Meta-Analysis.

We searched international databases to identify evidence that refer to the impact of perineural invasion on survival outcomes of patients with squamous cell vulvar cancer. We identified six retrospective cohort studies that investigated 887 patients. Of those, 234 (26.4%) had perineural invasion in the pathology analysis. Women with perineural invasion were more likely to have inguinal lymph node metastases (HR 3.45, 95% CI 1.12, 10.67). The impact of perineural invasion on progression-free survival rates was significant (HR 1.61, 95% CI 1.21, 2.15) as well as its impact on overall survival rates (HR 2.73, 95% CI 1.94, 3.84).