Reducing the radicality of surgery for vulvar cancer: are smaller margins safer?

Abstract

Vulvar cancer accounts for ~4% of all gynecological malignancies and the majority of tumors (>90%) are squamous cell (keratinizing, ~60% and warty/basaloid, ~30%). Surgical excision forms the foundation of treatment, with resection margin status being the single most influential factor when predicting clinical outcome. There has been a paradigm shift concerning surgical approaches and radicality when managing vulvar cancer within recent times, largely owing to a desire to preserve vulvar structure and function without compromising oncological outcome. As such the safety of the size of resection margin has been called into question. In this narrative review we consider the current literature on the safety of resection margins for vulvar cancer. PubMed, Medline and the Cochrane Database were searched for original peer-reviewed primary and review articles, from January 2005 to January 2020. The following search terms were used vulvar cancer surgery, vulvar squamous cell carcinoma, excision margins, adjuvant radiation. A pathological tumor margin of <8 mm has been widely considered to indicate "close" margins. This measurement after fixation of the tumor is considered comparable to a surgical resection margin of around 1cm, following an estimated 20% tissue shrinkage after formalin fixation and a 1-2cm clinical surgical margin in order to achieve the 8 mm final pathological margin. A surgical resection margin of 2-3mm does not appear to be associated with a higher rate of local recurrence than the widely used limit of 8 mm. As such the traditional practice of re-excision or adjuvant radiotherapy based on "close" surgical margins alone needs to be closely evaluated, since the attendant morbidity associated with these procedures may not be outweighed by oncological benefit.