Men with colon cancer tend to have more advanced tumors than women of the same age, according to a new study that suggests screening guidelines may need to be adjusted for sex and age. Currently, men and women age 50 and older are urged to get a colonoscopy to screen for growths or polyps that could form into tumors. Colorectal cancer is the fourth leading cancer killer worldwide, taking 610,000 lives per year. The study in the Journal of the American Medical Association examined 44,350 participants in a national screening colonoscopy program from 2007 to 2010 in Austria. The screenings look for adenomas, which are polyps or benign tumors as well as for particularly advanced adenomas and colorectal cancer. The analysis found "a significantly higher rate of these lesions among men compared with women in all age groups, suggesting that male sex constitutes an independent risk factor for colorectal carcinoma," according to the study. For instance, five percent of men age 50-54 had advanced adenomas compared to just 2.9 percent of women. The rate of colorectal cancer in 55-59-year-old men (1.3 percent) was about the same as in women a decade older (65-69-year-old women were diagnosed at a rate of 1.2 percent). The prevalence of colorectal cancer overall was twice as high among men, at 1.5 percent, compared to 0.7 percent in women. The researchers noted 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." However, the study stopped short of saying what that new age should be, saying further studies "are needed to demonstrate the relative clinical effectiveness of screening at different ages."