Ever being diagnosed with severe acne was associated with a higher risk of breast cancer (HR=1.23; 95% CI: 0.98, 1.54), particularly in women who were diagnosed prior to age 18 years (HR=1.40; 95% CI: 1.04, 1.90). Results were similar when limited to invasive cancers.5 Jun 2019
Severe Acne and Risk of Breast Cancer - PMC - NCBI
I had severe acne from aged 12 to 38 when I was cured by four months treatment with Roaccutane. During my teenage years I was given ultraviolet treatment to my chest and back while at University. That did improve my skin but I worried about the risk of skin cancer. I also took a lot of antibiotics none of which did much.