Genital melanoma: prognosis factors and treatment modality.

PURPOSE: Genital melanoma is a rare pathology. We present the experience of two comprehensive cancer centers in Lyon (France) in the management of genital melanoma in order to identify prognostic factors and optimal treatments.

METHODS: Between April 1992 and Mars 2014, 16 patients with a primary genital melanoma were referred to our department. Nine patients presented a vaginal melanoma, six vulvar melanomas and only one cervical melanoma. The median dimension of the lesion was 33.7 mm (5-100 mm). The AJCC stage ranged from IB to IIIC. 12 cases were the classic dark-blue flat melanoma and the other 4 cases were an atypical amelanotic tumor. Wide local surgery was performed in nine patients. A radical surgery was performed in six patients. In the large cervical melanoma, radiotherapy was performed as first-line treatment. In all the patients regional lymph node staging was performed. Adjuvant treatment was realized in nine patients.

RESULTS: Two patients are alive without recurrence. Only one patient was lost to the first follow-up. The other 13 patients experienced a rapid recurrence. The median disease-free survival and the median overall survival were 11.8 months (2-49 m) and of 30.4 m (11-144 m), respectively. The disease-free survival and overall survival could be linked to a clinical presentation (Breslow thickness and morphology of lesion) associated to the early diagnosis.

CONCLUSIONS: In our small series, the most important prognosis factor remains the tumor thickness. These rare lesions should be treated in experienced centers in order to improve their prognostic.