A population based study of factors associated with advanced cutaneous melanoma diagnosis in Ontario

Awardee: Meaghan Mavor

Graduate Program: MSc

Institution: Queen’s University

Supervisor(s): Timothy Hanna

ARCC Program Area(s): Health Systems, Services, and Policy

Competition: 2016

Project Summary:

Cutaneous malignant melanoma (hereafter melanoma) is the seventh most commonly diagnosed cancer in Canada, yet its management and outcomes remain understudied at the population level. Over the past several decades, the incidence and mortality rates of melanoma have been increasing internationally. Stage at diagnosis is highly related to prognosis, with lower stages having a 5-year survival rate of 98% and higher stages having a survival rate of only 18%. The stage of melanoma is dependent on disease-related factors such as tumour thickness, size, replication rate, ulceration, and whether it has spread to other body parts.

Studies in the United States (U.S.) and Europe have found disparate rates of advanced melanoma according to race/ethnicity, socioeconomic status (SES), age, sex, and area of residence. These factors are unrelated to melanoma growth; they should not fundamentally influence melanoma stage. Melanoma stage has yet to be examined in Ontario and, as such, the prevalence of advanced melanoma and the factors associated with it are currently unknown in this province. In addition, comprehensive and contemporary studies have yet to be conducted in the presence of a universal healthcare system, as we have in Canada, where access to care may be more equitable than in the U.S.

This thesis will be the first to describe the occurrence of advanced melanoma in Ontario. It will investigate whether factors that should not influence melanoma stage (e.g. age, sex, SES, and geography) are associated with advanced melanoma at time of diagnosis. Finally, to validate newly abstracted stage data used for this project, survival outcomes will be described according to thickness and American Joint Committee on Cancer (AJCC) 7th edition melanoma staging.

Findings from this study will contribute to the knowledge of cancer burden in Ontario and provide the foundation for future health services research on melanoma in Ontario. If melanoma stage is associated with factors that should not be involved with stage (e.g. age sex, SES, geography), future research can be performed to ascertain why these disparities exist and ways in which they can be improved. Public interventions can then be created for targeted groups of individuals that are disproportionately diagnosed with advanced stage melanoma.