Evaluation of Groin Lymphadenectomy Extent For Metastatic Melanoma

BACKGROUND: Spread of metastatic melanoma to the groin lymph nodes (LN) is a common event affecting about 350 people a year in Australia. Globally it has been shown that patients with involved groin LN, without proven pelvic LN disease on imaging receive 1 of 3 management strategies in equal proportions - inguinal lymphadenectomy (IL); ilio-inguinal lymphadenectomy (I-IL); or variable use of either depending on circumstances. Different experts have strong and polarised opinions favouring either IL or more extensive I-IL with existing cases series reporting conflicting data on best cancer outcomes. No high level evidence proves which operation is best. HYPOTHESIS: There will be no significant difference in DFS between patients having IL or I-IL, conditional on PET/CT scan showing no evidence of pelvic disease at the time of diagnosis of groin LN metastatic melanoma. AIMS: To provide a rational evidence base for management for melanoma to the groin LNs by randomly assessing the effect of each operation on DFS, distant DFS, overall survival (OS), morbidity - including early complications and longer-term rates of lymphedema as well as comprehensively assessed QOL. Also to clarify the reliability of PET/CT scans for staging pelvic LNs and evaluate any health economic benefits of I-IL over IL. TARGET POPULATION: To recruit 634 patients in 5 years. DESIGN: An Australian led, international, multi-centre, non-inferiority, phase III, prospective, randomised clinical trial comparing IL or I-IL for patients with metastatic melanoma to groin LNs and no evidence of pelvic disease on PET/CT. ENDPOINTS: DFS, Distant DFS, OS and QOL at 5 years. Accuracy of PET/CT for pelvic LN metastases. OUTCOMES: International standardization of care, improved cancer outcomes, improved QOL for patients with groin metastatic melanoma. Proof of principle about extent of surgery when PET/CT is clear in adjacent LN areas, leading to clinical trials investigating management of other lymph node fields.