Prognostic factors for recurrence and survival in uncommon variants of vulvar cancer.

Purpose: To analyze the prognostic factors of recurrence and overall survival in rare histotypes of vulvar cancer.
Methods: An international multicenter retrospective study including patients diagnosed with vulvar cancer was performed. One hundred centers participated in the study and 2453 vulvar cancer cases were enrolled from January 2001 until December 2005. After exclusion of squamous vulvar cancer, Paget´s disease and vulvar melanoma 112 tumors were analyzed for the present study.
Results: The mean age at diagnosis was 64.9 ± 17.2 years. 99 (88.4%) patients had a single lesion, in 25 (22.3%) cases the vulvar tumor involved the midline, and only 13 (11.5%) patients had clinically positive inguinal lymph nodes. The mean size of the lesion was 33.8 ± 33.9 mm. Regarding the surgical treatment, 2 (1.8%) patients underwent skinning vulvectomy, 63 (56.3%) local excision, 41 (36.6%) vulvectomy, 3 (2.7%) exenteration and 3 (2.7%) did not receive any surgical treatment. The mean free surgical margin was 8.2 ± 9 mm and 7 (6.2%) patients presented positive inguinal nodes. Radiotherapy was administered in 22 (19.6%) patients and it was performed postoperatively in all cases; 14 (12.5%) patients received adjuvant chemotherapy. The mean overall follow-up time was 44.1 ± 35.7 months. The risk factors associated with overall survival were chemotherapy and radiotherapy, tumor size and stromal invasion (p < 0.05). The only independent factor significantly associated with global recurrence and absence of metastasis was radiotherapy (p = 0.02 and p = 0.002, respectively).
Conclusion: Postoperative radiotherapy seems to be the only independent factor associated with recurrence and overall survival in uncommon types of vulvar cancer.