The impact of type 2 diabetes on melanoma stage (TNM) at the time of diagnosis and its association with sex: A Danish nationwide study.

Abstract

Background: Cancer has become the leading cause of death among individuals with type 2 diabetes (T2D) in high-income countries. T2D is suggested to directly influence cancer progression. However, the association between T2D and melanoma stage at diagnosis remains uncertain, as well as any potential sex disparities.

Objectives: To investigate the association between T2D and the melanoma TNM stage (Breslow thickness, ulceration status, lymph node metastases, and distant metastases) at the time of diagnosis and to assess whether the association is affected by sex.

Methods: A nationwide cross-sectional study was conducted, including all patients diagnosed with melanoma between 2004 and 2022 identified in the Danish Cancer Register. T2D status was ascertained using a validated register based algorithm. The association between T2D and melanoma stage was estimated using univariable and multivariable logistic regression analyses adjusted for sex, age, comorbidity, and year of diagnosis.

Results: The study included 30,315 individuals with melanoma. The multivariable analyses showed that T2D was associated with an increased adjust odds ratio (aOR) of tumour thickness > 4 mm (aOR 1.30, 95 %CI: [1.10-1.52]), the presence of ulceration (aOR: 1.25, 95 % CI: [1.09-1.43]), lymph node metastases (aOR 1.27 [1.10-1.47]), and distant metastases (aOR: 1.26 [1.01-1.56]). Furthermore, sex stratified analyses showed that T2D was associated with distant metastases in women, but not in men.

Conclusions: Individuals with T2D were more likely to be diagnosed with advanced stages of local, regional, and distant melanoma. This highlights the need for greater melanoma awareness and further research into treatment responses in individuals with T2D.