Equity in Melanoma Survival Masks Inequity in Diagnosis

Melanoma, while representing only about 10% of skin cancers, accounts for the majority of skin cancer–related deaths.¹ In Canada, melanoma ranks among the top 10 most common cancers, with incidence continuing to rise across provinces. Beyond biological risk factors such as ultraviolet exposure, social determinants of health—including socioeconomic status (SES) and access to care—are increasingly recognized as influential in cancer outcomes.² A recent retrospective study published in the Journal of Surgical Oncology investigated these associations in the context of Canada’s universal health care system, focusing on patients with melanoma treated surgically at The Ottawa Hospital between 1999 and 2023.³

Study Design and Cohort

The study examined 959 patients who underwent surgery for biopsy-proven melanoma. Researchers evaluated outcomes including overall survival, time to recurrence, and stage at presentation, while examining SES (measured by income quintiles based on postal codes) and distance from the treating hospital. Patients in the lowest and highest income quintiles (InQs) were compared most directly, though all quintiles were included in regression models. Other factors such as age, sex, and comorbidity index were also incorporated into the analyses.

Key Findings

The results revealed a nuanced picture of how socioeconomic and demographic variables affect melanoma outcomes:

• Income Quintile: Patients from higher-income neighborhoods were found to be less likely to present with advanced disease (stages II–IV) at diagnosis compared to those from lower-income areas (odds ratio: 0.865; p=0.004). However, SES did not significantly affect overall survival, stage III–IV disease, or recurrence time. This suggests that while higher SES may facilitate earlier diagnosis, treatment access within Canada’s centralized, publicly funded system may mitigate survival disparities.
• Distance to Care: Contrary to findings from studies in other healthcare systems, distance from the hospital was not associated with stage at presentation, recurrence, or survival. The authors suggest this may reflect effective regionalization of melanoma care in Eastern Ontario, where community hospitals refer patients to specialized cancer centers regardless of distance.
• Sex Differences: Female patients demonstrated longer time to recurrence (HR: 0.705; p=0.020) and lower odds of presenting with stage II–IV (p=0.049) or stage III–IV disease (p=0.009). These findings echo prior research suggesting that both biological and behavioral differences may contribute to more favorable outcomes in women.
• Treatment Patterns: Although overall rates of receiving adjuvant therapy did not differ significantly between income groups, the type of therapy did. Higher-InQ patients more often received immunotherapy or targeted therapy, while lower-InQ patients more commonly received radiation. This may reflect differences in disease features, eligibility, treatment era, or access preferences.

Interpretation and Context

The study underscores that even within a universal health care model, socioeconomic disparities persist at the point of diagnosis. Lower-income patients were more likely to present with ulcerated and more advanced melanomas, highlighting potential gaps in early detection. These disparities may stem from barriers in education, awareness of suspicious lesions, or access to dermatology and primary care services. Notably, survival outcomes appeared equalized once patients entered specialized care, reflecting the strength of centralized oncology services in Canada.

The lack of impact from geographic distance contrasts with prior studies in the United States and elsewhere, where distance has been linked to delayed diagnosis and worse outcomes. The authors attribute this difference to regionalized care pathways and universal coverage, which may buffer against travel-related inequities.

Limitations

Several limitations temper interpretation. The study excluded patients with unresectable stage III/IV disease, potentially underestimating late-stage burden. Melanoma in situ was also underrepresented, as many such cases are managed in community dermatology practices. Additionally, using area-level income data may not fully capture individual SES. Finally, the study spanned 2 decades, during which systemic therapy options evolved substantially, complicating interpretation of treatment trends.

Clinical Implications

For clinicians, the findings highlight the importance of vigilance in recognizing socioeconomic disparities in melanoma detection. While treatment outcomes appear equitable once patients reach specialized care, interventions aimed at improving early diagnosis—particularly in lower-income populations—remain critical. Public health strategies that enhance awareness, improve access to dermatology, and strengthen primary care referral pathways could reduce disparities in stage at diagnosis.

Conclusion

This Canadian study suggests that socioeconomic status influences melanoma stage at presentation but not survival once patients receive surgical treatment within a universal health care framework. Distance to hospital did not significantly impact outcomes, underscoring the benefits of centralized oncology care. Future research should further explore educational and systemic barriers that delay diagnosis among lower-income populations, with the goal of improving equity in melanoma outcomes.

References

1. Bertrand JU, Steingrimsson E, Jouenne F, Bressac-de Paillerets B, Larue L. Melanoma risk and melanocyte biology. Acta Derm Venereol. 2020;100(11):adv00139. 2020. doi:10.2340/00015555-3494
2. Ghazawi FM, Cyr J, Darwich R, et al. Cutaneous malignant melanoma incidence and mortality trends in Canada: A comprehensive population-based study. J Am Acad Dermatol. 2019;80(2):448-459. doi:10.1016/j.jaad.2018.07.041
3. King A, Brandts-Longtin O, Somayaji C, et al. Impact of social determinants on melanoma outcomes in Canada: A single-centre retrospective study. J Surg Oncol. 2025. doi:10.1002/jso.70069