Background:
Obesity is hypothesised to worsen melanoma prognosis, yet there is conflicting literature. Therefore, our study aimed to explore the association between body mass index (BMI) and melanoma prognosis (tumour stage at diagnosis and tumour recurrence) in patients with high-risk (T1b – T4a) primary cutaneous melanoma.
Methods:
For this prospective study, 700 patients with newly diagnosed stage T1 to T4b cutaneous melanoma were recruited between 2010 and 2014 in Queensland, Australia. We used logistic regression and Cox survival regression to evaluate the associations between BMI, tumour stage and tumour recurrence, respectively.
Results:
Obese participants were significantly more likely to have an earlier tumour stage at diagnosis compared to healthy-weight participants (adjusted odds ratio [OR] 1.93, 95% confidence interval [CI] 1.11 – 3.38, p-value 0.05). No association was found between BMI and melanoma recurrence at 7 years post-diagnosis of the primary tumour (adjusted hazard ratio [HR] 0.83, 95% CI 0.56 – 1.23, p-value 0.34 for overweight; HR 0.85, 95% CI 0.55 – 1.30, p-value 0.45 for obese).
Conclusion:
Our findings suggest obese patients are diagnosed at earlier tumour stages, yet BMI has no effect on melanoma recurrence.