Positive iliac and obturator nodes in melanoma: Survival and prognostic factors

Background: The need for deep groin dissection when superficial nodes contain metastatic melanoma is controversial. Methods: A review of 362 therapeutic groin dissections performed at our tertiary referral center between 1961 and 1995 revealed 71 patients (20%) with positive iliac and/or obturator nodes. This group was analyzed for survival rates, prognostic factors for survival, regional tumor control, and morbidity. Results: Patients with involved deep nodes exhibited overall 5-year and 10-year survival rates of 24% (SE, 5%) and 20% (SE, 5%), respectively. Independent prognostic factors for survival were the number of positive iliac nodes (P = .0011), the Breslow thickness (P = .0069), and the site of the primary tumor (P = .0075). Patients with an unknown primary tumor seemed to have better prognoses. Seven patients (10%) experienced recurrence in the surgically treated groin. The short- and long-term morbidity rates (infection, 17%; skin flap necrosis, 15%; seroma, 17%; mild/moderate lymphedema, 19%; severe lymphedema, 6%) compared well with those of other series studying inguinal as well as ilioinguinal dissections. Conclusions: From the present study it can be concluded that removal of deep lymph node metastases is worthwhile, because one of every five such patients survives for 10 years. Prognostic factors for survival are the number of involved iliac nodes, the Breslow thickness, and the site of the primary tumor. Long-term regional tumor control can be obtained for 90% of the patients. The morbidity of an additional deep lymph node dissection is acceptable.