San Francisco – Indoor tanning increases the risk of two types of non-melanoma skin cancer, particularly among people who start tanning at an early age, concludes a new study from the University of California, San Francisco.

Tanning beds have already been linked to malignant melanoma; this study examined non-melanoma cancers, which are the most common. Researchers analyzed medical articles published since 1985 involving approximately 80,000 people in six countries, according to a UCSF press release.

People who engaged in indoor tanning had a 67 percent higher chance of developing squamous cell carcinoma and a 29 percent greater risk of basal cell carcinoma. The risk was higher for people who began tanning before age 25.

Overall, researchers estimated indoor tanning causes more than 170,000 non-melanoma cases in the United States each year.

The study appeared online Oct. 2 in the journal BMJ.