Women more vulnerable to
risk of colorectal cancer from tobacco
Newswise — A new study of gender and risk factors for
colorectal cancer reveals that while both tobacco and
alcohol increase risk for colorectal cancer, women who smoke
are at higher risk. Researcher Anna L. Zisman, M.D. of
Evanston Northwestern Health Care presented these findings
at the 70th Annual Scientific Meeting of the American
College of Gastroenterology. Another study presented at ACG
of patients undergoing colonoscopy demonstrated that
patients over 75 benefit from colorectal cancer screening in
detecting cancer and potentially cancerous lesions and
experience no more complications from colonoscopy than
younger patients.
Smoking Significantly Increases Colorectal Cancer Risk in
Women
Smoking and alcohol use are well-established risk factors
for colorectal cancer. According to Dr. Zisman,
“Understanding interactions between genetic and
environmental factors, such as smoking and alcohol use, is
critical for colorectal cancer risk stratification, and will
help us design effective screening strategies.”
Dr.
Zisman and her colleagues looked at women’s susceptibility
compared to men. Using the IMPAC Medical Registry Services
Cancer Information Resource File, a large database from over
350 teaching and community hospitals, the investigators
conducted a regression analysis of gender, tobacco and
alcohol use. They found that while age of onset of
colorectal cancer was slightly younger in males than females
in the non-smoking/non-drinking group, current smokers had a
markedly decreased age of presentation for both men and
women. Similarly, alcohol use was associated with an earlier
age of diagnosis in males and females. An assessment of the
differential sensitivity to smoking and alcohol use in men
and women revealed that women are sensitive to smoking as a
risk factor for colorectal cancer but not alcohol. “We can
see that while both men and women who use tobacco and
alcohol are diagnosed with colorectal cancer at an earlier
age, the effect of tobacco is significantly greater in
women,” said Dr. Zisman.
Colorectal Cancer Screening Benefits Patients 75 Years and
Older
Most guidelines recommend that screening for colorectal
cancer should begin at age 50 for individuals at average
risk. “However there is no consensus regarding the age at
which we should stop screening,” commented Aaron Walfish,
M.D. of Beth Israel Medical Center in New York. According to
Dr. Walfish, “Older patients often have other health
problems that increase the risk of undergoing endoscopy, so
we need more evidence regarding the usefulness of screening
in this older population. Our data support continued
screening of elderly patients.”
Dr.
Walfish and his colleagues conducted a retrospective
analysis of 178 patients 75 and older and 318 patients
between ages 65 and 69. In both age groups, the researchers
found that a similar percentage of patients had polyps or
masses (43 percent in the 75 and older group vs. 42 percent
in the 65 to 69 group), and that a similar percentage had
larger polyps or masses (49 percent in the 75 and older
group vs. 58 percent in the 65 to 69 group had polyps
greater than or equal to 1 cm.) There were no complications
from the screening procedure reported in either age group.