Trends in Immunotherapy (IO) Use and Survival Among Patients With High-Incidence Stage IV Cancers Across the United States

Background and Objectives: IO has transformed cancer management, but its adoption in advanced cancer patients varies by tumor type. With more Stage IV patients undergoing surgery, understanding site-specific outcomes in these challenging patients is essential. We aimed to evaluate IO use and survival trends for Stage IV cancer patients across high-incidence cancers in the US. Methods: Patients diagnosed with Stage IV prostate, breast, melanoma, colorectal, renal, bladder, lung, or pancreas cancer were identified from the National Cancer Database (2004–2020). Cochrane–Armitage test and Kaplan–Meier methods assessed IO and overall survival across three periods: 2004–2010, 2011–2015, and 2016–2020. Results: Among 1 425 731 Stage IV cancer patients, most had lung (50.0%), pancreas (12.5%), and breast cancer (9.3%), while the least had melanoma (2.2%). From periods 1 to 3, IO use increased from 1.0% to 24.6%, notably in melanoma (9.5% to 58.5%, p < 0.001). Melanoma exhibited the greatest survival gains (median survival: 7.1 to 14.9 months). Absolute increases in 3-year overall survival rates ranged from 3.4% in pancreas (1.7% to 5.1%) to 21.4% in melanoma (15.7% to 37.1%). Conclusions: Utilization of IO is tumor-site specific and associated with improved survival rates for Stage IV cancer, with varied success across types. Variations in receipt highlight ongoing challenges to ensure equitable adoption.