Clinicopathological demographics of malignant melanoma of the vulva and vagina in Japan: Japanese Gynecologic Oncology Group (JGOG)/Japanese Skin Cancer Society (JSCS)—Intergroup Study.

Abstract

e22106 Background: Malignant melanomas of the vulva (VuM) and vagina (VaM) represent a unique subgroup of malignant melanomas with important differences in biological properties and treatment. In Japan adequate surveys have not been performed.The objective of this study was to elucidate the clinicopathological demographics and outcomes of VuM and VaM in Japan. Methods: Women with invasive VuM or VaM were identified from a medical records. Data on clinician (Gynecologist or Dermatologist), age, location, node status, ulceration, mitotic count, histologic subtype, American Joint Committee on Cancer (AJCC) stage, primary surgery, and surgical margin were collected. The Kaplan-Meier method was used to analyze progression free survival (PFS) and overall survival (OS). Univariate and multivariate regression models were used to identify factors significantly related to survival. Results: A total of 217 patients (pts) were identified; 109 (50.2%) had VuM and 108 (49.8%) had VaM. The median age of the subjects was 67 years (range [R], 29-96 years). Surgery was performed in 84.3% of the women with VuM and 83.3% of those with VaM. The median depth of invasion was 4.5 mm (R, 0.1-12 mm). Ulceration was documented in 47.9% (104/217) of the lesions. Nodal status was positive in 60 pts (27.6%), negative in 149 pts (68.7%), and unknown in 8 (3.7%) pts. The AJCC stage was stage I in 37 pts (17.1%), II in 106 pts (48.8%), III in 46 pts (21.2%), and IV in 28 pts (12.9%). Nodular melanoma was the most common subtype (48.8%). The median PFS was 16.8 months in pts with VuM (95% confidence interval [CI] 23.1-87.7) and 15.6 months in pts with VaM (95% CI 8.4-12.6). The median OS was 43.9 months (95% CI 60-138) in pts with VuM and 31.1 months (95% CI 24.8-45.3) in pts with VaM. Univariate analysis showed that vaginal location, nodal metastases, stage, surgery, and surgical margin were associated with poorer PFS, whereas nodal status, histologic subtype, stage, surgery, and surgical margin were associated with poorer OS. Multivariate analysis showed that only disease stage (hazard ratio [HR] = 3.09; 95% CI = 1.73-5.49) was associated with poorer PFS. Surgical margin was the only independent factor influencing OS (HR = 2.39; 95% CI = 1.48-3.80). Conclusions: The overall outcomes of VuM and VaM remain poor in Japan. In particular, the outcomes of VaM are worse than those reported previously. AJCC stage and surgical margin are important predictors of survival. Regardless of disease stage, suitable surgical resection is required. Clinical trial information: UMIN000025968.