Smoking linked with rectal cancer risk

Women who smoke cigarettes appear to have nearly twice the risk of developing rectal cancer compared with women who do not smoke. Researchers from the Ohio State University, Columbus looked at the incidence of colorectal cancer among more than 140,000 women between 50 and 79 years old, who participated in Women's Health Initiative, a long-term observational study. Of these women, 51 per cent reported that they have never smoked, 42 per cent were past smokers and 7 per cent were current smokers. Over a period of almost eight years, on average, 1,242 of the women developed invasive colorectal cancer. Of these cancers, 176 were rectal cancer. Compared with women who never smoked, current smokers were 95 per cent more likely to develop rectal cancer, but did not have an increased risk of colon cancer. These relationships held after the researchers adjusted the data to account for other factors known to influence colorectal cancer development. These factors included age, ethnicity, family history, physical activity; nonsteroidal anti-inflammatory drugs, hormone therapy; alcohol use; dietary intake of calcium, fibre, fat and red meat; waist circumference and the women's history of diabetes. A similar analysis did not associate passive smoking with an increased risk for colorectal cancer. The findings suggest the risk of rectal cancer among women increases with the number of cigarettes they smoke per day, longer smoking duration, and older age at smoking cessation. Thus, women who choose to continue smoking should receive regular screening for colorectal cancer. However, smoking cessation may be a better way not just to prevent colorectal cancer, but reducing other health risks as well.