Smoking increases the risk of developing colon cancer in both males and females, however, the risk is higher among women smokers, according to a new study.

The research was conducted by a team of experts from the University of Tromsø in Norway and was published in Cancer Epidemiology, Biomarkers & Prevention.

The experts also found that the more and longer a woman smoked, the greater her risk for colon cancer.

Inger Torhild Gram, M.D., Ph.D., professor in the Department of Community Medicine at the University of Tromsø in Norway, said:

“Globally, during the last 50 years, the number of new colon cancer cases per year has exploded for both men and women. Our study is the first that shows women who smoke less than men still get more colon cancer.”

The study involved a large Norweigan cohort of over 600,000 males and females. Gram and her colleagues looked at the link between cigarette smoking and colon cancer, by examining the tumor location.

The volunteers from four surveys established by the National Health Screening Service of the Norwegian Institute of Public Health underwent a short health exam and filled out questionnaires regarding smoking habits, exercise, and other lifestyle factors.

The subjects were followed by linkage to the Central Population Register and the Cancer Registry of Norway. About 4,000 new colon cancer cases were diagnosed during an average 14 years of follow-up.

Women smokers had a 19% elevated risk compared with those who never smoked, while men smokers had an 8% higher risk compared to non-smokers.

The results also showed that women who began smoking when they were 16 years or younger and women who had smoked for 40 years or longer had a considerably elevated likelihood – of about 50%.

Additionally, the dose-response link between the number of cigarettes smoked each day, number of years smoked, and the number of pack-years smoked and colon cancer risk was stronger for females than it was for males, the authors pointed out.

Gram concluded:

“The finding that women who smoke even a moderate number of cigarettes daily have an increased risk for colon cancer will account for a substantial number of new cases because colon cancer is such a common disease.

A causal relationship between smoking and colorectal cancer has recently been established by the International Agency for Research on Cancer of the World Health Organization, but unfortunately, this is not yet common knowledge, neither among health personnel nor the public.”

A previous report showed that not smoking, exercising more, and cutting down on red meat and alcohol can reduce a person’s risk of colon cancer.

Written by Sarah Glynn