Gastrointestinal metastases from melanoma: Does surgical resection improve survival when performed in combination with immunotherapy?

Abstract

340 Background: Prior studies have shown the benefits of metastasectomy and more recently, immunotherapy, in Stage IV melanoma. We report the largest series of gastrointestinal (GI) melanoma metastases, in order to clarify the role of surgical resection in the setting of systemic treatment options. Methods: A review of our institutional melanoma database identified all patients with hollow viscus GI metastases diagnosed between 1971 and 2013. Patient age and sex; primary tumor location, thickness and ulceration; GI-metastasis free interval; and types of treatment were analyzed. The primary endpoint was melanoma-specific survival (MSS), measured from the diagnosis of GI metastases. Survival analyses compared combination therapy to immunotherapy (i.e. vaccine, interleukin-2, interferon, ipilimumab) or surgery alone. Operative patients were further stratified by surgical intent (curative or palliative). Results: The 393 study patients had a median GI-metastasis free interval of 49.5 (0 – 416.0) months from the initial diagnosis; their mean age at GI metastases was of 53.5 ± 14.1 years. Median MSS was 20.0 months with surgery plus immunotherapy (n=160), 13.0 months with surgery alone (n=111), 8.0 months with immunotherapy alone (n=64), and 5.0 months with neither treatment (n=58) (p<0.001). By multivariable analysis, age at GI metastasis diagnosis (HR=1.014; p=.014), truncal melanoma site (HR=1.659; p=.017), immunotherapy (HR=0.675; p=.030), and metastasectomy (HR=0.544; p<.001) were significant predictors of MSS. Surgical intent was known in 98 patients: curative surgery had a median MSS of 30.0 months (n=49) and palliative surgery had a median MSS of 12.0 months (n=49) (p=.015). Conclusions: Treatment of GI melanoma metastases should use a combination of metastasectomy and immunotherapy, instead of either modality alone. Select patients are likely to obtain an enhanced benefit from GI metastasectomy, specifically curative surgery, in the setting of newer immunotherapy options.

Malignant melanoma of the cecum and small intestine

“…In one study involving 393 patients with malignant melanoma and gastrointestinal metastases, median survival was 20.0 months with surgery plus immunotherapy (n ¼ 160), 13.0 months with surgery alone (n ¼ 111), 8.0 months with immunotherapy alone (n ¼ 64), and only 5.0 months with neither treatment (n ¼ 58) (P < 0.001). 10 Therefore, resection of metastatic lesions in conjunction with immunotherapy should be explored as a treatment option for these patients. Our case was unique because multiple areas of the gastrointestinal tract were involved throughout our patient's clinical course; his care required a wide spectrum of detection and treatment modalities, which ultimately resulted in an improved outcome.…”