Hamashima Chisato, Sobue Tomotaka, Muramatsu Yukio, Saito Hiroshi, Moriyama Noriyuki, Kakizoe Tadao
Research Center for Cancer Prevention and Screening, National Cancer Center, Chuo-ku, Tokyo 104-0045, Japan.
Jpn J Clin Oncol. 2006 May;36(5):301-8. doi: 10.1093/jjco/hyl022. Epub 2006 May 30.
The Research Center for Cancer Prevention and Screening program is a one-arm prospective study designed to evaluate the effect of multiple modalities for cancer screening. Basic programs consist of screening tests for cancer of the lung, esophagus, stomach, colon, rectum, liver, gall bladder, pancreas and kidneys, in addition to prostate cancer screening for males and breast, cervical, endometrial and ovarian cancer screenings for females.
To investigate the possibility of overdiagnosis, we compared the observed numbers with expected numbers based on the model.
We calculated the expected number of cancers on the basis of negative or positive history of screening tests within the previous year, based on assumed sensitivity and sojourn time. Observed numbers of screen-detected cases for stomach, colorectal, lung, prostate and breast cancer were compared with expected numbers.
From February 2004 to January 2005, 3786 participants were enrolled in our study. The overall cancer detection rate was 5.8% (119/2061) for males and 4.1% (71/1725) for females. No statistically significant difference was found between observed and expected cases for colorectal cancer screening, gastric cancer screening for females and lung cancer screening for males. Observed numbers of breast, prostate and lung cancer for females exceeded those expected (P < 0.05).
Although cancer screening programs in the present study increased the detection of potentially curable cancers, these modalities, particularly lung, breast and prostate screening, might detect cancers which would not necessarily be clinically significant. We should therefore weigh up benefit and harm for such cancer screening programs.
癌症预防与筛查研究中心项目是一项单臂前瞻性研究，旨在评估多种癌症筛查方式的效果。基本项目包括对肺癌、食管癌、胃癌、结肠癌、直肠癌、肝癌、胆囊癌、胰腺癌和肾癌的筛查测试，此外还包括针对男性的前列腺癌筛查以及针对女性的乳腺癌、宫颈癌、子宫内膜癌和卵巢癌筛查。
为了调查过度诊断的可能性，我们将观察到的病例数与基于模型的预期病例数进行了比较。
我们根据前一年筛查测试的阴性或阳性病史，基于假定的敏感性和停留时间计算了预期癌症病例数。将观察到的胃癌、结直肠癌、肺癌、前列腺癌和乳腺癌筛查发现病例数与预期病例数进行了比较。
2004年2月至2005年1月，共有3786名参与者纳入我们的研究。男性的总体癌症检出率为5.8%（119/2061），女性为4.1%（71/1725）。在结直肠癌筛查、女性胃癌筛查和男性肺癌筛查中，观察到的病例数与预期病例数之间未发现统计学上的显著差异。女性乳腺癌、前列腺癌和肺癌的观察病例数超过预期（P<0.05）。
尽管本研究中的癌症筛查项目增加了可治愈癌症的检出率，但这些筛查方式，特别是肺癌、乳腺癌和前列腺癌筛查，可能会检测出不一定具有临床意义的癌症。因此，我们应该权衡此类癌症筛查项目的利弊。
