New research from Austria finds men have a higher rate of advanced colon cancer tumors than women of the same age and suggests male sex is a risk factor for the disease. The researchers propose this means men should be screened earlier than women, but do not say whether this ought to be by delaying the age when women are initially offered screening or bringing forward the age men are offered it.
You can read how Dr Monika Ferlitsch, of the Austrian Society for Gastroenterology and Hepatology in Vienna, and colleagues, analyzed the results of more than 40,000 screening colonoscopies to reach these conclusions in a paper published in the September 28 issue of JAMA.
Their results show that men have a higher rate of advanced tumors compared to women in all the age groups they examined.
Colorectal or bowel cancer is the fourth leading cancer killer worldwide and claims 610,000 lives a year.
Even though some studies show that men are at a greater risk for advanced tumors than women, current practice is that both men and women aged 50 and over are urged to have an initial screening colonoscopy. This looks for adenomas, which are polyps or benign tumors and also detects advanced adenomas and colorectal cancer.
Ferlitsch and colleagues investigated the most appropriate age for initial screening colonoscopy in groups of male and female patients to attain a higher detection rate of advanced tumors and cancer which could result in lower death rates.
For their study, they examined data from 44,350 participants (51% women) in Austria who took part in a national colonoscopy screening between 2007 and 2010. The median age of the females was 60.7 years and of the males was 60.6 years.
They found a significantly higher rate of colorectal cancer and advanced tumors among men compared with women in all age groups, suggesting that “male sex constitutes an independent risk factor for colorectal carcinoma and indicating new sex-specific age recommendations for screening colonoscopy”.
For example, they found the prevalence of colorectal cancer overall among men was double that of women (1.5% compared to 0.7%).
And among 50- to 54-year-olds, 5% of men had advanced adenomas compared to only 2.9% of women.
And they also found that men in their mid-50s had a similar rate of colorectal cancer as women ten years older (CRC rate was 1.3% in men aged 55-59 and 1.2% in women aged 65-69).
Another measure they examined was the average number needed to screen (NNS) to detect adenomas. They found this to be 5.1 for all individuals, 4.0 for men, and 6.7 for women.
However, in 50- to 54-year-old women, NNS was nearly twice as high as in men at the same age (9.3 for men compared with 5.4 for women). And among 45- to 49-year-old men, NNS was 5.9, similar to the 6.0 found for women aged 60 to 64 years.
The authors recommend that:
“… deciding whether to adjust the age at which screening begins also requires considering whether the recommended age for women should be older or the recommended age for men younger.”
They also urge further prospective studies be done to establish the relative clinical effectiveness of colonoscopy screening at different ages.
Written by Catharine Paddock PhD