Association of socioeconomic status with secondary primary malignancy risk and mortality.

Abstract

e21559 Background: Patients with a melanoma history are at higher risk of developing a secondary primary malignancy (SPM), an independent and distinct cancer that is not a metastasis from the initial one. There is currently limited literature on how socioeconomic status (SES) is associated with risk of SPMs, despite 2.1% of U.S. population living with a melanoma history. This study aims to identify the risk factors associated with getting another primary cancer after initial early-stage melanoma diagnosis, the risk factors associated with getting a higher stage SPM, and the risk factors associated with dying from stage IV melanoma. Methods: A retrospective cohort study was conducted using NIH SEER database of 426,732 stage 0/I/II melanoma patients from 2006-2020 and 1,089 metastatic melanoma patients from 2010-2020. Patient’s SES quintile was calculated using census tract information including median household income, house value/rent, education index, etc. Data on primary and secondary malignancies were analyzed using binomial and ordinal logistics regression. Five-year survival was analyzed using a Kaplan Meier and multivariate Cox model including prognostic factors such as Breslow thickness, number of lymph nodes involved, tumor mitotic rate, and ulceration status. Results: Patients with higher SES have a higher incidence of SPMs (Stage I/II Group 1*: OR 0.82, 95% CI: [0.78, 0.86]). However, patients with lower SES have a higher risk of developing higher stage SPMs (Stage I/II Group 1: OR 1.39, 95% CI: [1.28, 1.51]). As patients move down each SES quintile, their risk of developing a more advanced stage SPM increases. Subgroup analysis found lower SES patients are at higher risk of developing more advanced second melanoma, but not prostate, breast, or lung cancer after their initial melanoma diagnosis. Five-year cause-specific survival analysis revealed metastatic melanoma patients with lowest SES are most at risk of dying (Group 1: HR 1.54, 95% CI: [1.15, 2.08]). *Group 1 is the lowest SES group; reference group is Group 5 (highest SES). Conclusions: This study adds to the literature by illustrating patients with lower SES are at greater risk of developing higher stage SPMs after their initial melanoma---especially a higher stage second melanoma---whereas higher SES patients are more likely to be diagnosed. Our findings present disparities in skin cancer screening post-melanoma diagnosis. Current clinical guidelines recommend patients previously treated for early-stage melanoma to undergo routine skin cancer screenings. However, patients with lower SES often experience structural barriers including lack of health insurance, geographic inaccessibility, and suboptimal transportation options. Our findings highlight the need for targeted interventions to address SES-related disparities in melanoma prevention among a population that already has a past melanoma diagnosis.