Introduction
The role of diet in cancer prognosis has sparked considerable research interest in recent years. However, this relationship remains largely unexplored in melanoma. This study aims to investigate the association between the Healthy Eating Index (HEI) and melanoma outcomes, specifically tumour ulceration at diagnosis and risk of death due to metastatic melanoma in patients with high-risk primary melanoma.
Methods
In this prospective cohort study, 700 patients with newly diagnosed stage T1b to T4b cutaneous melanoma with no clinically detectable metastases were recruited between 2010 and 2014 in Queensland, Australia. HEI scores were calculated from a food questionnaire and categorised into low, medium, and high scores, where increasing scores indicated improved diet quality. We used a logistic regression and a Cox survival regression to evaluate the associations between the HEI, tumour ulceration, and death due to metastatic melanoma, respectively.
Results
Participants with a low HEI score were significantly more likely to have an ulcerated melanoma at diagnosis compared to those with a medium HEI score (adjusted odds ratio [OR] 1.49, 95% confidence interval [CI] 0.93 – 2.39, p-value 0.04). Additionally, participants with a high HEI score had a significantly reduced risk of dying from metastatic melanoma within 7 years of diagnosis of the primary tumour, compared to those with a low HEI score (adjusted hazard ratio [HR] 0.50, 95% CI 0.25 – 0.98, p-value 0.05).
Conclusion
Our research indicates that patients with a poor diet had a higher risk of their melanoma being ulcerated at diagnosis, which is a marker of tumour inflammation and associated with poorer prognosis. On the contrary, patients with a healthy diet had a lower risk of dying from metastatic melanoma within 7 years of diagnosis.