据9月28日刊《美国医学会杂志》上的一则研究披露，一项对超过4万个结肠镜筛检结果的分析发现，在各个接受检查的年龄组中，男性比女性有着更高的晚期肿瘤发病率；从而提示，接受最初结肠镜筛检的个人年龄应该具有性别特异性。
尽管某些研究显示，男性比女性有着更大的罹患晚期结肠直肠肿瘤的年龄特异性风险，但要求具有平均风险的病人做结肠直肠癌（CRC）结肠镜筛检的年龄对男女两性来说皆为50岁，这是因为CRC的发病率会在60岁之后增加。 根据文章的背景资料，结肠镜筛检的目标是发现并清除腺瘤（息肉或良性肿瘤），特别是晚期腺瘤（AA）。
奥地利维也纳的奥地利胃肠病学与肝病学协会的Monika Ferlitsch, M.D.及其同事开展了一项研究，旨在查明对男女病患组来说最合适的进行初次结肠镜筛检的年龄，希望籍此获得对腺瘤、AA及CRC的更高的检测率，从而降低CRC的死亡率。 这项研究包括了4万4350名在2007年至2010年间在奥地利参与某个为期4年的全国性结肠镜筛检计划的人。 在这些参与者中，有51%为女性，其中位数（中点）年龄为60.7岁（女性）及60.6岁（男性）。
结肠镜筛检的结果包括：有34.4%的病人有息肉（n = 15,267），有0.4%的病人有结肠癌（n = 162），有0.2%的人有直肠癌（n = 92）。 有61.4%（n = 27,212）的结肠镜检查没有发现异常。 在接受筛检的人中，有19.7%的人发现有腺瘤，有6.3%的人发现有AAs，有1.1%的人有CRCs。 腺瘤的发病率在男性中为24.9%，在女性中为14.8%；在50-54岁的男性中，这一发病率为18.5%，而在同一年龄组的女性中的该发病率为10.7%，但50-54岁的男性的该发病率却与65-69岁的妇女中的发病类似，为17.9%。 对所有的个体来说，发现腺瘤所需的筛检平均数（NNS）为5.1，但男性为4.0，女性为6.7。 在50-54岁的女性中，NNS比相同年龄的男性要高出近两倍（9.3 vs. 5.4）。 在45-49岁的男性中，NNS为5.9；这一数字与年龄在60-64岁的女性的NNS（6.0）相似。
文章的作者写道：“在我们的研究中，腺瘤、AAs和CRC的年龄及性别特异性的流行率分析表明，在所有的年龄组中，男性发生这些损害的几率都比女性显著要高；这提示男性性别构成了独立的结肠直肠癌的风险因子，表明有必要对做结肠镜提出新的性别特异性的筛检年龄建议。”
相关英文论文摘要：
Sex-Specific Prevalence of Adenomas, Advanced Adenomas, and Colorectal Cancer in Individuals Undergoing Screening Colonoscopy
Context Although some studies have shown that men are at greater age-specific risk for advanced colorectal neoplasia than women, the age for referring patients to screening colonoscopy is independent of sex and usually recommended to be 50 years.
Objective To determine and compare the prevalence and number needed to screen (NNS) for adenomas, advanced adenomas (AAs), and colorectal carcinomas (CRCs) for different age groups in men and women.
Design, Setting, and Patients Cohort study of 44 350 participants in a national screening colonoscopy program over a 4-year period (2007 to 2010) in Austria.
Main Outcome Measures Prevalence and NNS of adenomas, AAs, and CRCs in different age groups for men and women.
Results The median ages were 60.7 years (interquartile range [IQR], 54.5-67.5 years) for women and 60.6 years (IQR, 54.3-67.6 years) for men, and the sex ratio was nearly identical (51.0% [22 598] vs 49.0% [21 572]). Adenomas were found in 19.7% of individuals screened (95% CI, 19.3%-20.1%; n = 8743), AAs in 6.3% (95% CI, 6.1%-6.5%; n = 2781), and CRCs in 1.1% (95% CI, 1.0%-1.2%; n = 491); NNS were 5.1 (95% CI, 5.0-5.2), 15.9 (95% CI, 15.4-16.5), and 90.9 (95% CI, 83.3-100.0), respectively. Male sex was significantly associated with a higher prevalence of adenomas (24.9% [95% CI, 24.3%-25.4%] vs 14.8% [95% CI, 14.3%-15.2%]; P < .001; unadjusted odds ratio [OR], 1.9 [95% CI, 1.8-2.0]), AAs (8.0% [95% CI, 7.6%-8.3%] vs 4.7% [95% CI, 4.4%-4.9%]; P < .001; unadjusted OR, 1.8 [95% CI, 1.6-1.9]), and CRCs (1.5% [95% CI, 1.3%-1.7%] vs 0.7% [95% CI, 0.6%-0.9%]; P < .001; unadjusted OR, 2.1 [95% CI, 1.7-2.5]). The prevalence of AAs in 50- to 54-year-old individuals was 5.0% (95% CI, 4.4%-5.6%) in men but 2.9% (95% CI, 2.5%-3.4%) in women (adjusted P = .001); the NNS in men was 20 (95% CI, 17.8-22.6) vs 34 in women (95% CI, 29.1-40; adjusted P = .001). There was no statistical significance between the prevalence and NNS of AAs in men aged 45 to 49 years compared with women aged 55 to 59 years (3.8% [95% CI, 2.3%-6.1%] vs 3.9% [95% CI, 3.3%-4.5%] and 26.1 [95% CI, 16.5-44.4] vs 26 [95% CI, 22.5-30.2]; P = .99).
Conclusion Among a cohort of Austrian individuals undergoing screening colonoscopy, the prevalence and NNS of AAs were comparable between men aged 45 to 49 years and women aged 55 to 59 years.
