Smoking has long been tied to a number of cancers, and now another tumor type, skin cancer, may join that list.
A new review of data finds that lighting up may boost the risk of a common type of non-melanoma skin cancer.
Researchers sifted through the results of 25 studies conducted in 11 countries worldwide. Most of the studies included middle-aged to elderly people.
This analysis revealed that smoking was associated with a 52 percent increased risk of cutaneous squamous cell carcinoma skin cancer, according to Jo Leonardi-Bee, of the U.K. Center for Tobacco Control Studies at the University of Nottingham in England
Squamous cell and basal cell carcinomas -- collectively known as non-melanoma skin cancer -- account for about 97 percent of all skin cancers. The incidence of non-melanoma skin cancer is rising worldwide, with about 2 to 3 million new cases each year.
The authors said they found no clear association between smoking and basal cell carcinomas.
This study highlights the importance for Doctors to actively survey high-risk patients, including current smokers, to identify early skin cancers, since early diagnosis can improve prognosis because early lesions are simpler to treat compared with larger or neglected lesions.
This isn't the first time smoking has been linked to skin cancer. In December, researchers reporting in the journal Cancer Causes Control said that women diagnosed with squamous cell carcinoma were twice as likely to have been smokers than those who were free of the disease.
The study, led by Dana Rollison, an associate member in the Moffitt Cancer Center department of cancer epidemiology, in Tampa, Fla., also found that men who were long-term smokers were at slightly higher risk for basal cell carcinomas.
Speaking at the time, Dr. Jeffrey Dover, associate clinical professor of dermatology at Yale University Medical School, said the findings weren't surprising because "we know cigarette smoke contains carcinogens" and smokers are "blowing the smoke and ash around their faces all day."
Squamous cell cancer occurs in the epidermis, the top layer of skin, and can spread to other organs. Basal cell skin cancer occurs in the dermis, the skin layer beneath the epidermis. While it does not spread to other organs, it is far more common than squamous cell cancer.