Risk of second primary cancer among patients with a first primary appendiceal adenocarcinoma.

• DOI: 10.1200/jco.2025.43.4_suppl.819
• Publication Date: 2025-01-27T14:35:52Z
• Authors: Andreana Natalie ...; Richard M Goldberg; Mary Kay Washington; Caitlin C. Murphy
• Keywords: Primary cancer; Primary (astronomy)

819 Background: Incidence rates of rare appendiceal cancers are increasing across the United States. Although this is suggestive a growing population cancer survivors over time, risk second primary specific to patients with first adenocarcinoma remains unknown. Methods: We conducted population-based study adults (age ≥18 years) diagnosed from 1992 2021, using data Surveillance, Epidemiology, and End Results (SEER) Program. estimated cumulative incidence cancer, defined as any at least 3 months after adenocarcinoma, Fine Gray methods account for competing death. For comparison general population, we also standardized ratios [SIRs], or observed number relative expected based on age-, sex-, race-specific rates. Results: A total 5,827 (mean age 58.0 years; 51.8% female; 68.5% non-Hispanic White) were identified during period, whom 418 developed cancer. The most common types prostate (17.7%), colorectal (14.4%), female breast (10.5%), lung (8.4%), melanoma (6.0%). At 10 20 years diagnosis, was 7.5% (95%CI 6.8%-8.4%) 11.7% 10.5%-12.9%), respectively. Cumulative significantly differed by sex (p<0.01) diagnosis (early-onset [age<50] vs late-onset; p<0.01). example, post-diagnosis, 6.4% 5.4%-7.4%) females 8.8% 7.6%-10.1%) males. overall SIR 1.12 (95%CI, 1.02-1.23)—corresponding 14.8 excess per 10,000 person-years. SIRs were: 1.07 0.84-1.35) prostate, 2.12 1.63-2.70) colorectal, 0.91 0.68-1.19) breast, 0.81 0.58-1.09) lung, 1.20 0.79-1.73) melanoma. Conclusions: Approximately one in every 13 States will be within years. After an have 12% double compared population. Implementation prevention early detection strategies (e.g., colonoscopy screening, genetic testing) clinical priority.