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News Release

May 9, 2013

Women Smokers May Have Greater Risk for Colon Cancer Than Men
Visiting Professor at the University of Hawaii Cancer Center Makes Discovery

HONOLULU, HI – A study conducted by Inger Torhild Gram, MD, PhD, visiting professor at the University of Hawaii Cancer Center found that female smokers may have a greater risk of developing colon cancer than male smokers. This data was recently published in Cancer Epidemiology, Biomarkers & Prevention a journal of the American Association for Cancer Research.

“Globally, during the last 50 years, the number of new colon cancer cases per year has exploded for both men and women,” said Inger Torhild Gram, MD, PhD, professor in the Department of Community Medicine at the University of Tromsø in Norway. “Our study is the first that shows women who smoke less than men still get more colon cancer.”

Gram and colleagues found that female smokers had a 19 percent increased risk compared with never-smokers, while male smokers had an 8 percent increased risk compared with never-smokers. They also found that the longer and more frequent a woman smoked also increased their risk of getting colon cancer.

Gram and her colleagues examined the association between cigarette smoking and colon cancer, by tumor location, in a large Norwegian cohort of more than 600,000 men and women. The participants from four surveys initiated by the National Health Screening Service of the Norwegian Institute of Public Health had a short health exam and completed questionnaires about smoking habits, physical activity and other lifestyle factors. The participants were followed by linkage to the Cancer Registry of Norway and the Central Population Register. During an average 14 years of follow-up, close to 4,000 new colon cancer cases were diagnosed.

In the next phase of this research, Gram and colleagues from the University of Hawaii Cancer Center will examine this association using data from the Cancer Center’s Multiethnic Cohort Study. “It will be very exciting to look at the different ethnicities,” said Gram. “We will be able to see across different ethnic groups, not just Caucasians.”

Gram hopes to have preliminary results in November 2013 to report back to the American Association for Cancer Research.

“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,” said Gram. “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.”

Colorectal cancer is the third most commonly diagnosed cancer and the second leading cause of cancer death in men and women combined in the United States, according to the National Cancer Institute (NCI), part of the U.S. National Institutes of Health. About 72 percent of cases arise in the colon and about 28 percent in the rectum.

About Inger Torhid Gram, MD, PhD

Inger Torhild Gram is a professor in the Department of Community Medicine at the University of Tromsø in Norway. While on sabbatical, she is a visiting professor at the University of Hawaii Cancer Center. This is her third visit to the University of Hawaii Cancer Center. She was previously at the Center from 2003 to 2004 and again from 2007 to 2008.

Her study has been garnering extensive national as well as international news attention:

http://www.foxnews.com/health/2013/05/01/female-smokers-have-higher-colon-cancer-risk/

http://www.aljazeera.com/video/europe/2013/05/20135117949696969.html

http://www.bbc.co.uk/news/health-22350264