Background: To the authors' knowledge, the potential prognostic value of DNA ploidy in vulvar melanoma has not been evaluated in previous series.
Methods: Clinical data and follow-up information were retrieved from the hospital records of 75 patients treated from 1956 to 1987. Histopathologic specimens were reviewed for histologic type, depth of invasion, vessel invasion, and ulceration. Flow cytometric DNA measurements were performed on paraffin embedded samples.
Results: Forty-three patients had International Federation of Gynecology and Obstetrics Stage I disease, 14 Stage II, 8 Stage III and 10 Stage IV. Sixty-five patients were treated by surgery, six by radiotherapy, and four patients with advanced disease received no therapy. The surgical procedure was local excision in 17 patients, vulvectomy in 22, and radical vulvectomy with inguinal lymph node dissection in 26. Five- and 10-year corrected survival rates were 46% and 37%, respectively. Recurrences were seen in 43 (66%) of the patients treated by surgery. Independent prognostic factors for corrected survival in the entire group of 75 patients were inguinal lymph node metastases (P = 0.016), angioinvasion (P = 0.027), tumor localization to clitoris, and multifocal tumors (P = 0.043). For the 65 patients treated by surgery, independent prognostic factors for disease free survival were angioinvasion (P < 0.001), age at diagnosis (P = 0.003), DNA ploidy (P = 0.004), and ulceration (P = 0.027). The independent prognostic factors for long term survival were tumor localization to clitoris (P = 0.018), DNA ploidy (P = 0.045), and inguinal lymph node involvement (P = 0.053). Radical surgery did not improve disease free or long term survival.
Conclusions: DNA ploidy is an independent factor that predicts prognosis in patients with vulvar melanoma, and should be considered together with previously known factors. Radical surgery does not improve prognosis and is not recommended when the inguinal lymph nodes are clinically negative.