Association of tea consumption and cutaneous squamous cell carcinoma.

Laboratory and epidemiologic studies suggest a protective effect of tea consumption on risk of cutaneous squamous cell carcinoma (SCC). We designed a case-control study to examine the association between putative protective exposures, including tea consumption, and SCC risk using a large health maintenance organization population. Cases (n=415) were defined as Kaiser Permanente Northern California (KPNC) members with a pathology-verified SCC in 2004 and controls (n=415) were age-, gender-, and race-matched members with no previous history of skin cancer. Tea consumption and SCC risk factors were ascertained by questionnaire. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using conditional logistic regression to estimate the association of SCC with regular use, as well as dose and duration of tea consumption. Risk factor adjusted models included education, smoking, hair and eye color, skin type, family history of skin cancer, and history of freckling, sunburns, sun exposure, and tanning bed use. Adjusted analyses showed no reduction in SCC risk with regular consumption of tea (OR=1.11, 95% CI: 0.81-1.54). Examining duration, dose, and combined duration and dose exposure variables did not alter findings. We found no evidence that tea consumption was associated with cutaneous SCC risk.