Lung cancer is the third leading cause of death in LA County, while colorectal cancer is the eighth leading cause of death, according to the Los Angeles County Department of Public Health. Most are aware of the association between cigarette smoking and the risk of lung cancer; however, less are aware of the relationship between smoking and colorectal cancer risk. A new study has found that smoking increases the risk of colorectal cancer in women to a greater degree than it does in men. A team of Scandinavian researchers published their findings online in the Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.
The study authors note that smoking is a recently established risk factor for colon cancer and that Norwegian women are at high risk for colon cancer. Therefore, they conducted a study to determine whether women were more susceptible to smoking-attributed colon cancer than men. The study group comprised 602,242 individuals aged 19 to 67 years at enrollment in 1972–2003. The researchers reviewed data on these individuals that were contained in national registries through December 2007.
The investigators found that during an average follow-up of 14 years, altogether 3,998 (46% women) subjects developed colon cancer. Female ever-smokers had a 19% (1.19-fold increased risk) and male ever-smokers had an 8% (1.08-fold increased risk) increased risk of colon cancer compared with never smokers. They also assessed risk based on the amount of smoking. For all the four dose–response variables examined, female ever-smokers in the most exposed category of smoking initiation, of daily cigarette consumption, of smoking duration, and of pack-years of smoking had a significantly increased risk of more than 20% for colon cancer overall and of more than 40% for proximal colon cancer, compared with never smokers. The colon is divided into two regions: the proximal colon (the upper portion, which includes the cecum, appendix, ascending colon, hepatic flexure, transverse colon and splenic flexure); and the distal colon (lower portion, which includes the descending colon, sigmoid colon, and rectum).
The authors concluded that female smokers may be more susceptible to colon cancer and especially to proximal colon cancer than male smokers.
According to the American Cancer Society, colorectal cancer is one of the leading causes of cancer-related deaths in the United States. However, early diagnosis often leads to a complete cure. Almost all colon cancer starts in glands in the lining of the colon and rectum. When most people and when doctors talk about colorectal cancer, this is generally what they are referring to. There is no single cause for colon cancer. Nearly all colon cancers begin as noncancerous (benign) polyps, which slowly develop into cancer.
You have a higher risk for colon cancer if you:
Are older than 60
Are African American or Eastern European descent
Eat a diet high in red or processed meat
Have cancer elsewhere in the body
Have colorectal polyps
Have inflammatory bowel disease (Crohn’s disease or ulcerative colitis)
Have a family history of colon cancer
Have a personal history of breast cancer
Certain genetic syndromes also increase the risk of developing colon cancer. Two of the most common are hereditary nonpolyposis colorectal cancer (HNPCC), also known as Lynch syndrome, and familial adenomatous polyposis (FAP).
What you eat may play a role in your risk of colon cancer. Colon cancer may be associated with a high-fat, low-fiber diet and red meat. However, some studies found that the risk does not drop if you switch to a high-fiber diet, so the cause of the link is not yet clear.
