An analysis of reported independent prognostic factors for survival in squamous cell carcinoma of the vulva: is tumor size significance being underrated?

OBJECTIVE To assess independent prognostic factors described in the literature. Thus, to identify different risk groups. METHODS Review of the records with a diagnosis of primary vulvar squamous cell carcinoma (January/1992-January/2012). INCLUSION CRITERIA depth of stromal invasion (DSI) >1mm, pathological tumor size >2 cm, and pathological tumor-free margin ≥ 8 mm. Patients who underwent neoadjuvant therapy due to locoregionally advanced vulvar cancer were excluded. All the patients underwent radical, both local and regional, surgery. Adjuvant radiation therapy was administered to all patients with positive nodes. Features of lymph nodes, tumor size, age, grade, lymphovascular space invasion (LVSI), DSI, type of radical surgery, pathological margin distance and stage were evaluated by univariate and multivariate analysis. RESULTS 194 patients were included. Median age: 67 years. Median follow-up: 62 months. 5-year OS and DFS: 65.5% and 58.2%. Positive lymph nodes were found in 91 (46.9%) patients. After a multivariate analysis, the number of positive lymph nodes, extra-nodal growth, pathologic tumor size and DSI proved to be independent prognostic factors. A high risk group for failure to survive (5y-OS 24%) was identified: tumor size ≥ 6-7.9 cm and DSI >4mm or ≥ 8 cm irrespective of DSI; and extra-nodal growth or ≥2 positive lymph nodes irrespective of tumor size and DSI. CONCLUSIONS A new high-risk group was identified based on different cutoff values for tumor size, extra-nodal growth and number of positive lymph nodes. This could be very important in the tailored treatment of a specific group of patients with bulky primary tumors and a poorer prognosis.