Higher Risk of Melanoma-related Deaths for Patients Residing in Rural Counties: A Surveillance, Epidemiology, and End Results Program Study
Description
Background: Prior literature has demonstrated a persistent and increasing “rural mortality penalty” (RMP) where those living rural areas have higher mortality rates compared to metropolitan counterparts. Objective: Analyze the latest SEER data to determine the current extent of the RMP on melanoma diagnoses. Methods: Tumor and county characteristics, incidence, and mortality rates were compared using two-tailed t-tests. Relationships between rurality, time-to-treatment, and Breslow depth (BD) were analyzed using a Poisson generalized linear model and log-link function that accounted for race, age, gender, and income. For survival, a multivariate Cox Proportional Hazard (CPH) model controlling for the same factors plus tumor depth was employed. Results: 169,903 cases were analyzed with 11% of the cohort residing in rural counties. These patients had thicker tumors (BD 1.34mm vs. 1.18mm p<0.001) and lower rates of T1 melanoma (BD <0.75mm, 52.6% vs. 58.2%, p<0.001). Incidence was higher (25.4 vs 21.7 cases/100,000 people/year, p<0.001), and ten-year survival was lower in the rural cohort overall (87.69 vs. 90.24%, p<0.001) and for localized melanoma (91.11% vs. 93.26%, p<0.001). Rural patients had shorter average time-to-treatment, 0.30 vs. 0.35 months (p<0.001). CPH model confirmed higher hazard ratio for disease specific death (DSD) for rural patients, 1.13 (p <0.001; 95% CI: 1.08, 1.19). Conclusion: The RMP for patients with melanoma conferred a 13% higher risk of DSD and 17% higher incidence, indicating a significant disease burden in this population. This is likely due barriers to care, limiting early screening and diagnosis. Limitations include lack of covariates, county-level data, unknown confounders.