Abstract 4338: Immunotherapy in resected stage III melanoma: An analysis of the National Cancer Database
Authors: Moyers Justin T. , Chong Esther G. , Mitchell Jasmine , Patel Amie , Jeong Il Seok Daniel , Nagaraj Gayathri 
Published: September 2020

Abstract
Introduction: Even after curative intent resection, stage III melanoma carries poor prognosis and traditional chemotherapy has limited efficacy. Adjuvant immune checkpoint inhibitor (ICI) therapy utilizing the anti-CTLA-4 agent, ipilimumab, was shown to improve survival following resection in Stage III disease. Ipilimumab was FDA approved for adjuvant therapy in 2015. The National Cancer Database (NCDB) is a joint project of the Commission on Cancer of the American College of Surgeons and the American Cancer Society and is the largest clinical cancer registry in the world covering 72% of new cancer diagnoses in the US. We aimed to assess the real-world survival data along with sociodemographic factors associated with receipt of adjuvant immunotherapy using the NCDB.
Methods: We queried the NCDB for stage III patients since 2015. The most recent dataset available includes treatment data from 2015 and 2016 and survival data from 2015. Patients were included who had documented surgery to primary site; those with systemic therapy before surgery were excluded. Patients were divided into receipt of immunotherapy or no receipt of immunotherapy after surgery; those without documentation of either were excluded. Those who received chemotherapy as their systemic therapy were excluded. Factors compared between the two groups included age, sex, diagnosis year, pathologic stage group, Charlson-Deyo score, primary payer and state Medicaid expansion status, income, treatment region, and facility type. Survival analyses were performed by Kaplan-Meier method. Logistic Regression was used to examine factors associated with immunotherapy receipt.
Results: 4,093 patients met criteria to be analyzed for survival with 25% (n=1,014) receiving immunotherapy. Median overall survival has yet to be reached for either treatment group; whereas, the 30-month survival was rate was 78% (95%CI; 74-82%) for those receiving adjuvant immunotherapy versus 73% (95% CI; 72-74%) when immunotherapy was not given (p=0.051). However, adjuvant immunotherapy given to resected stage IIIC patients improved survival 32.8 versus 28.0 months (p&lt;0.01). 8,160 patients met inclusion criteria for treatment pattern analysis of which 28% (n=2,260) received immunotherapy after surgery. Charlson-Deyo Scores of 1-3, 2015 as year of diagnosis, and Medicare as primary payer had lower percentage of patients receiving immunotherapy.
Conclusion: We provide the first early analysis of the NCDB in the era of adjuvant ICI. Adjuvant immunotherapy in resected stage IIIC melanoma yielded a superior survival advantage. Additionally, sociodemographic factors appear to play a role in receiving adjuvant immunotherapy.
Citation Format: Justin T. Moyers, Esther G. Chong, Jasmine Mitchell, Amie Patel, Il Seok Daniel Jeong, Gayathri Nagaraj. Immunotherapy in resected stage III melanoma: An analysis of the National Cancer Database [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4338.