Melanoma brain metastases: the impact of nodal disease

Brain metastases (BMs) are a major source of mortality and morbidity in patients with melanoma. This study assesses prognostic nodal factors in patients with nodal metastatic melanoma with respect to the development of BMs. The aim was to identify a high risk subset that may benefit from brain directed management. Prospective surgical and clinical trial databases identified patients who had had nodal dissections and were seen through the Princess Alexandra Hospital Melanoma clinic between August 1995 and June 2010. Patient data was collected and event data was updated from medical imaging and clinical records. The primary endpoint was the rate of development of BMs. 474 patients were identified as having nodal dissections. Two hundred and eighty-seven patients (61%) were male with a median age of 52 (39-66). The most common nodal dissection site was axilla 190 (40%), followed by groin 154 (32.5%) and neck 130 (27.5%). Adjuvant radiotherapy to the nodal basin was delivered to 134 patients (28%). BMs occurred in 61 patients (12.9%) with a median time of 13.87 months from dissection. No lymph node characteristics were significantly associated with the development of BMs including: nodal region (p=0.72), nodal size (p=0.08), number of involved nodes (p=0.36), presence of extra-capsular spread (p=0.47) and AJCC N stage. There was no significant association between primary ulceration (p=0.37) or location and development of BMs. It appears that for patients with resected stage III melanoma there is no histopathological lymph node feature associated with the development of BMs. This highlights the importance of identifying molecular markers in nodal melanoma which may predict for BMs to further direct site-specific therapy.