Targeted Therapeutic Approaches in Vulvar Squamous Cell Cancer (VSCC): Case Series and Review of the Literature

Abstract

Therapeutic options in recurrent or metastasized vulvar squamous cell cancer (VSCC) not amenable to radiotherapy or radical surgery are limited. Evidence for the use of targeted therapies is sparse. All patients with VSCC treated at the Gynecological Cancer Center Hamburg-Eppendorf 20132019 were retrospectively evaluated for targeted therapeutic approaches. Furthermore, a MEDLINE, EMBASE, Web of Science, Scopus, and OVID database search was performed using the terms: vulvar cancer AND targeted therapy, erlotinib, EGFR, bevacizumab, VEGF, pembrolizumab, or immunotherapy. Twelve of 291 patients (4.1%) with VSCC received at least one targeted therapy at our institution. Previously, one or more platinum-based chemotherapy was applied to all patients [median 3.5 previous lines (range 25)]. In the erlotinib subgroup, two of five patients (40%) achieved stable disease (SD), while two patients (2/5, 40%) experienced partial response (PR). Treatment was given as monotherapy in second/third line for a median of 3.4 months (range 26 months). Bevacizumab (n=9) was given as maintenance therapy after platinum-based first-line chemotherapy (9/9); best response was complete response (CR) (n=2/9 22.2%). Median duration of treatment was 7 months (range 413 months) with two patients still under ongoing treatment. Best response in the pembrolizumab (n=3) subset was SD (n=1/3 33%). Treatment was given as monotherapy in second/third line for a median of 3.3 months (range 34 months). Nine of 12 patients (75%) experienced treatment-related adverse events (TRAEs), most commonly grade 1/2. Rapidly evolving antibody treatments have proven clinical benefit especially in HPV-driven tumor entities; however, clinical investigations in VSCC are still limited. These reported cases provide evidence for the clinical utility and feasibility while ensuring an acceptable safety profile.