Prognostic factors for local recurrence of squamous cell carcinoma of the vulva: A systematic review

Background: In patients treated for early-stage squamous cell vulvar carcinoma local recurrence is reported in up to 40% after ten years. Knowledge on prognostic factors related to local recurrences should be helpful to select high risk patients and/or to develop strategies to prevent local recurrences.

Objective: This systematic review aims to evaluate the current knowledge on the incidence of local recurrences in vulvar carcinoma related to clinicopathologic and cell biologic variables.

Data sources: Relevant studies were identified by an extensive online electronic search in July 2017.

Study eligibility criteria: Studies reporting prognostic factors specific for local recurrences of vulvar carcinoma were included.

Study appraisal and synthesis methods: Two review authors independently performed data selection, extraction and assessment of study quality. The risk difference was calculated for each prognostic factor when described in two or more studies.

Results: Twenty-two studies were included; most of all were retrospective and mainly reported pathologic prognostic factors. Our review indicates an estimated annual local recurrence rate of 4% without plateauing. The prognostic relevance for local recurrence of vulvar carcinoma of all analyzed variables remains equivocal, including pathologic tumor free margin distance <8mm, presence of lichen sclerosus, groin lymph node metastases and a variety of primary tumor characteristics (grade of differentiation, tumor size, tumor focality, depth of invasion, lymphovascular space invasion, tumor localization and presence of human papillomavirus).

Conclusions: Current quality of data on prognostic factors for local recurrences in vulvar carcinoma patients does not allow evidence-based clinical decision making. Further research on prognostic factors, applying state of the art methodology is needed to identify high-risk patients and to develop alternative primary and secondary prevention strategies.