Ventura Leonardo, Zappa Marco, Carreras Giulia, Ciatto Stefano, Grazzini Grazia
ISPO Cancer Research and Prevention Institute, Florence, Italy.
Tumori. 2011 Sep-Oct;97(5):547-50. doi: 10.1177/030089161109700501.
The best screening strategy for colorectal cancer is still debated. We simulated two screening strategies, namely flexible sigmoidoscopy (single episode) and immunological fecal occult blood test (FOBT) (five biennial rounds) and comparing their results as regards advanced adenomas and colorectal cancer detection.
A Markov model was developed to estimate the number of advanced adenomas and colorectal cancer detected with the two compared screening strategies. Two different scenarios, namely a) where the same compliance (50%) at both flexible sigmoidoscopy and immunological FOBT invitation is applied, and b) where the actual compliance observed at a national level (immunological FOBT, 45%; flexible sigmoidoscopy, 30%) is applied.
In scenario a), immunological FOBT would detect a total of 20,573 adenomas and 3,952 colorectal cancers, performing 74,507 total colonoscopies compared to 20,939 and 2,511, respectively, detected by flexible sigmoidoscopy, with 17,985 total colonoscopies. In scenario b), immunological FOBT would detect 17,845 advanced adenomas with 65,215 colonoscopies performed compared to 12,672 detected by flexible sigmoidoscopy with 10,796 colonoscopies. The probability of having a colonoscopy for a subject attending all the five immunological FOBT rounds was 15.9%.
The simulation suggests that also immunological FOBT screening may achieve a substantial detection of advanced adenomas and therefore may have an impact on colorectal cancer incidence.
结直肠癌的最佳筛查策略仍存在争议。我们模拟了两种筛查策略，即柔性乙状结肠镜检查（单次）和免疫粪便潜血试验（FOBT）（五年内每两年进行一轮），并比较它们在晚期腺瘤和结直肠癌检测方面的结果。
建立了一个马尔可夫模型，以估计通过这两种对比筛查策略检测到的晚期腺瘤和结直肠癌的数量。两种不同的情况，即：a）柔性乙状结肠镜检查和免疫FOBT检查邀请的依从性相同（50%）；b）采用全国实际观察到的依从性（免疫FOBT，45%；柔性乙状结肠镜检查，30%）。
在情况a）中，免疫FOBT总共将检测到20,573例腺瘤和3,952例结直肠癌，总共进行74,507次全结肠镜检查，相比之下，柔性乙状结肠镜检查分别检测到20,939例和2,511例，总共进行17,985次全结肠镜检查。在情况b）中，免疫FOBT将检测到17,845例晚期腺瘤，进行65,215次结肠镜检查，相比之下，柔性乙状结肠镜检查检测到12,672例，进行10,796次结肠镜检查。参加所有五次免疫FOBT检查的受试者接受结肠镜检查的概率为15.9%。
模拟结果表明，免疫FOBT筛查也可能大量检测到晚期腺瘤，因此可能对结直肠癌发病率产生影响。
