To determine the incidence of local recurrence of vulvar squamous cell carcinoma in relation to tumor- and/or precursor lesion free pathologic margins.

Consecutive patients with primary vulvar squamous cell carcinoma surgically treated in two Dutch expert centers between 2000 and 2010 were included. All pathology slides were independently reviewed by two expert gynecopathologists, and local recurrence was defined as any recurrent disease located on the vulva. Time to first local recurrence was compared for different subgroups using univariable and multivariable Cox-regression analyses.

In total 287 patients with a median follow-up of 80months (range 0-204) were analyzed. The actuarial local recurrence rate ten years after treatment was 42.5%. Pathologic tumor free margin distance did not influence the risk on local recurrence (HR 1.03 (95% CI 0.99-1.06)), neither using a cutoff of eight, five, or three millimeters. Multivariable analyses showed a higher local recurrence rate in patients with dVIN and LS in the margin (HR 2.76 (95% CI 1.62-4.71)), in patients with dVIN in the margin (HR 2.14 (95% CI 1.11-4.12)), and a FIGO stage II or higher (HR 1.62 (95% CI 1.05-2.48)).

Local recurrences frequently occur in patients with primary vulvar carcinoma and are associated with dVIN (with or without LS) in the pathologic margin rather than any tumor free margin distance. Our results should lead to increased awareness among physicians of an ongoing risk for local recurrence and need for life-long follow-up. Intensified follow-up and treatment protocols for patients with dVIN in the margin should be evaluated in future research.