Clinical outcomes after pulmonary metastasectomy for melanoma: a population-based study

Background — Resection of pulmonary metastases is an important treatment option for patients with oligometastatic melanoma. There are currently no published data available on population-level outcomes. Here, we report outcomes of a registry-based study of patients who underwent lung resection for cutaneous melanoma metastases.

Methods — The study population was all cases of cutaneous melanoma in Ontario, Canada, with resection of pulmonary metastases from 2004 to 2012. Melanoma cases were identified using the population-based Ontario Cancer Registry and were linked with hospital records to identify thoracic surgery. Pathology reports from the Ontario Cancer Registry were used to confirm the histology of resected lesions and determine tumor-related prognostic factors. Overall survival was described, and multivariable Cox regression utilized.

Results — Ninety-nine patients underwent resection of cutaneous melanoma lung metastases. Mean age was 58 years. Sixty-day postoperative mortality was 0%. Two-year and 5-year overall survival from time of resection was 44% and 21%, respectively (95% confidence intervals: 34% to 54% and 12% to 31%, respectively). Two-year overall survival was 57% for lesion size less than 1.5 cm; 43% for lesion size 1.5 to 2.2 cm; and 35% for lesion size 2.2 cm or greater (confidence intervals: 35% to 73%, 26% to 59%, and 19% to 52, respectively). In the multivariable stepwise selected model, the only significant variable was size 2.3 cm or greater (hazard ratio 1.64, confidence interval: 1.001 to 2.68). Greater lesion size was correlated with positive margin status (p = 0.04); there were no survivors beyond 2 years with positive margins.

Conclusions — In this unselected population-based study, 21% of patients were 5-year survivors after pulmonary metastasectomy for melanoma. There was worse survival with greater lesion size. Greater lesion size was associated with positive margin status.