The impact of effective systemic therapies on surgery for stage IV metastatic melanoma.


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Henry Smith1,Ruben Cohen2,Kroopa Joshi2,Dirk Strauss2,Andrew Hayes2,James Larkin2,Myles Smith2
1The Royal Marsden Hospital/The Institute of Cancer Research,2The Royal Marsden Hospital

Abstract

Background

The prognosis of metastatic melanoma has drastically improved in recent years with the evolution of effective systemic therapies (EST). The impact of EST on the role of surgery in Stage IV melanoma is unclear. We sought to characterise the patterns and outcomes of surgery in patients with Stage IV melanoma before and after the introduction of EST.

Method

Patients undergoing surgery in the context of Stage IV melanoma were identified from institutional patient records. Patients were grouped into those referred before-EST (2003-2007) and those referred after-EST (2011-2015).

Results

A total of 138 patients underwent surgery for Stage IV melanoma during the study period, with 69 patients in the before-EST and after-EST cohorts. No significant difference in the number of operations/patient performed between cohorts was noted. However, the pattern of operations altered with a significant decrease in in-transit excisions (0.9% vs 19.4%, p < 0.001) and an increase in abdominal metastasectomies (21.1% vs 4.2%, p < 0.001) in the after-EST cohort. Novel indications for surgical intervention were noted in the after-EST cohort, with an increase in patients undergoing potentially curative operations (15.9% vs 4.3%, p = 0.045). Survival following surgery was prolonged in the after-EST cohort (median survival 16 months vs 6 months, p < 0.001), with stage at initial metastasectomy (Stage 4a, HR 0.45 (0.28-0.73), p = 0.001) and treatment with immune checkpoint inhibitors (HR 0.38 (0.25-0.60), p < 0.001) found to be associated with prolonged survival.

Conclusion

Surgery remains important in the management of Stage IV melanoma, with evolving indications and patterns of intervention after the introduction of EST. Surgery for abdominal metastases is increasingly common, emphasising the importance of the inclusion of abdominal surgeons in the multidisciplinary management of an increasingly complex population of patients.