Superficial Inguinal and Radical Ilioinguinal Lymph Node Dissection in Patients with Palpable Melanoma Metastases to the Groin - An Analysis of Survival and Local Recurrence

The present study addresses the question whether an extended ilioinguinal dissection as compared to an only superficial inguinal dissection improves survival and/or local tumour control after the appearance of palpable melanoma metastases to the groin. We retrospectively analysed the data of 104 patients with 69 ilioinguinal and 35 superficial inguinal dissections (median follow up 127 months). Prognostic factors of survival and groin recurrence were assessed using Kaplan-Meier estimation and Cox proportional hazards model. By multifactorial analysis, metastatic involvement of two lymph nodes or less was associated with a significantly better survival rate than involvement of >2 or pelvic nodes (p=0.0002). After radical ilioinguinal dissection, patients with extremity-located primaries had a better prognosis than patients with truncal primaries (p=0.03). Tumour infiltration of the ilio-obturator compartment was found to be an independent factor of poor prognosis (p=0.0009). The probability of recurrence in the dissected groin paralleled the number of positive nodes and significantly increased if intransits were observed (p=0.0002). The extent of surgery, Breslow thickness, epidermal ulceration, sex, age and adjuvant chemotherapy neither significantly influenced survival nor local control rates. In summary, when metastatic inguinal nodes become palpable, the presence of pelvic metastases indicates systemic disease. After therapeutic groin dissection, local recurrence and survival depend rather on regional tumour burden than on the extent of surgery.