Blog | Friday, July 6, 2012

QD: News Every Day--Caffeine associated with less basal cell carcinoma

Caffeine may help the body clear skins cells damaged by the ultraviolet rays of sunlight, suggesting a way to potentially reduce basal cell carcinoma, researchers reported.

Researchers applied data from the Nurses' Health Study and the Health Professionals Follow-up Study to prospectively examine risks of basal cell carcinoma (nearly 23,000 cases), squamous cell carcinoma (nearly 2,000 cases), and melanoma (741 cases).

Results appeared in Cancer Research.

There were nearly 113,000 people studied, nearly 73,000 female nurses and nearly 40,000 male health professionals. The amount of caffeine intake from all dietary sources was inversely associated with basal cell carcinoma risk. Compared with the lowest quintile, the highest quintile had the lowest risk (women: relative risk [RR], 0.82 in women; 95% confidence interval [CI], 0.77 to 0.86; men RR, 0.87; 95% CI, 0.81 to 0.94; Ptrend less than 0.0001 in both).

Compared with individuals who consumed less than one cup per month of caffeinated coffee women who consumed more than 3 cups a day had the lowest risk of basal cell carcinoma (RR, 0.79; 95% CI, 0.74 to 0.85; Ptrend less than 0.0001). For men, results were RR 0.90; 95% CI, 0.80 to 1.01; Ptrend=0.003).

Caffeine from tea, soda and chocolate was also inversely associated with lower basal cell carcinoma risk, while decaffeinated coffee was not. Caffeine intake was not inversely associated with risks of squamous cell carcinoma or melanoma.

Caffeine is suspected to induce apoptosis in UV-damaged keratinocytes, a mechanism shown in mice models. This could explain the lowered basal cell carcinoma, the researchers said. In contrast, damaged melanocytes limit go into a senescent state instead of undergoing apoptosis, so anything that affects apoptosis wouldn't matter for melanoma.

Basal cell carcinoma accounts for approximately 80% of newly diagnosed skin cancers and 30% of all newly diagnosed cancers in the United States, and its rate is still increasing by 4% to 8% per year, potentially creating a scenario in which basal cell carcinoma incidence could equal all other cancers combined. And, with 40% to 50% of patients with a primary carcinoma developing basal cell carcinomas within 5 years, the potential morbidity and burden could increase considerably.

"Given the nearly one million new cases diagnosed each year in the United States modification in daily dietary factors with even small protective effects may have great public health impact," the authors wrote.