Background: Adrenal gland metastases (AGMs) are common in advanced-stage melanoma, occurring in up to 50% of patients. The introduction of immune checkpoint inhibitors (ICIs) has markedly altered the outcome of patients with melanoma. However, despite significant successes, anecdotal evidence has suggested that treatment responses in AGMs are significantly lower than in other metastatic sites. We sought to investigate whether having an AGM is associated with altered outcomes and whether ICI responses are dampened in the adrenal glands. Patients and Methods: We retrospectively compared ICI responses and overall survival (OS) in 68 patients with melanoma who were diagnosed with an AGM and a control group of 100 patients without AGMs at a single institution. Response was determined using RECIST 1.1. OS was calculated from time of ICI initiation, anti–PD-1 initiation, initial melanoma diagnosis, and stage IV disease diagnosis. Tumor-infiltrating immune cells were characterized in 9 resected AGMs using immunohistochemical analysis. Results: Response rates of AGMs were significantly lower compared with other metastatic sites in patients with AGMs (16% vs 22%) and compared with those without AGMs (55%). Patients with AGMs also had significantly lower median OS compared with those without AGMs (3.1 years vs not reached, respectively). We further observed that despite this, AGMs exhibited high levels of tumor-infiltrating immune cells. Conclusions: In this cohort of patients with melanoma, those diagnosed with an AGM had lower ICI response rates and OS. These results suggest that tissue-specific microenvironments of AGMs present unique challenges that may require novel, adrenal gland–directed therapies or surgical resection.
Submitted June 1, 2020; final revision received December 15, 2020; accepted for publication December 16, 2020.
Published online August 4, 2021.
Author contributions: Study concept and design: All authors. Data acquisition: All authors. Data analysis and interpretation: All authors. Manuscript preparation: All authors. Final approval: All authors.
Disclosures: Dr. Lewis has disclosed receiving grant/research support and personal fees from Roche/Genentech. Dr. McCarter has disclosed receiving grant/research support from Merck & Co., Inc. Dr. Mushtaq has disclosed owning stock and having other ownership interests in Abbott Laboratories, Amgen, Boston Scientific, Bristol Myers Squibb, Celgene Corp Company, Edwards Lifesciences, Gilead Sciences, Johnson & Johnson, and Medtronic. The remaining authors have disclosed that they have not received any financial considerations from any person or organization to support the preparation, analysis, results, or discussion of this article.
Funding: This work was supported in part by funding from the Patten-Davis Foundation, the Moore Family Foundation, the University of Colorado Department of Surgery Academic Enrichment Fund, University of Colorado Cancer Center Support Grant (P30CA046934), and the Cancer League of Colorado.