Genital melanoma: prognosis factors and treatment modality

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.

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.

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.

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.