Controversies in vulvar cancer: revisiting the margin of error

Despite an oftentimes radical surgical approach when treating patients with early-stage vulvar cancer, local recurrence occurs in approximately 40% of cases. Surgery in this setting can result in significant morbidity; however, treatment failure is associated with high mortality rates. Historically, many guidelines recommended a tumor-free margin ≥8 mm in the surgical treatment of vulvar cancer, although this is largely consensus-based and supported by a few small retrospective case series. Recently, numerous retrospective studies have found no association between a tumor-free margin of <8 mm and locoregional recurrence. Emerging evidence suggests that the presence of differentiated vulvar intra-epithelial neoplasia and lichen sclerosis at the pathologic margin may also play a role in local recurrence; however, data are retrospective and heterogenous, and the definition of what a "safe" tumor-free margin is remains unclear. However, increasing evidence has failed to demonstrate the beneficial role of re-excision or adjuvant radiation in the setting of margins of <8 mm. These additional treatments are associated with significant morbidity and have a negative impact on patients' quality of life; thus, they should be reserved solely for patients with positive margins. One of the main challenges in finding the ideal tumor-free margin is that the rarity of vulvar cancer makes prospective and randomized controlled trials difficult to conduct. Therefore, it is imperative that we make a concerted effort as a field to collaborate across nations and institutions, promote centralization of care for rare tumors, and prioritize future work to better understand the nature of this disease.