von Euler-Chelpin My, Kuchiki Megumi, Vejborg Ilse
Department of Public Health, University of Copenhagen, Øster Farimagsgade 5, DK-1014 Copenhagen, Denmark.
Department of Radiology, University Hospital of Copenhagen, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen, Denmark.
Cancer Epidemiol. 2014 Oct;38(5):619-22. doi: 10.1016/j.canep.2014.06.006. Epub 2014 Jul 14.
Studies have shown that women with a false-positive result from mammography screening have an excess risk for breast cancer compared with women who only have negative results. We aimed to assess the excess risk of cancer after a false-positive result excluding cases of misclassification, i.e. women who were actually false-negatives instead of false-positives.
We used data from the Copenhagen Mammography Screening Programme, Denmark. The study population was the 295 women, out of 4743 recalled women from a total of 58,003 participants, with a false-positive test during the screening period 1991-2005 and who later developed breast cancer. Cancers that developed in the same location as the finding that initially caused the recall was studied in-depth in order to establish whether there had been misclassification.
Seventy-two cases were found to be misclassified. When the women with misclassified tests had been excluded, there was an excess risk of breast cancer of 27% (RR=1.27, 95% confidence interval (CI), 1.11-1.46) among the women with a false-positive test compared to women with only negative tests. Women with a false-positive test determined at assessment had an excess risk of 27%, while false-positives determined at surgery had an excess risk of 30%.
The results indicate that the increased risk is not explained only by misclassification. The excess risk remains for false-positives determined at assessment as well as at surgery, which favours some biological susceptibility. Further research into the true excess risk of false positives is warranted.
研究表明，与仅获得阴性结果的女性相比，乳腺钼靶筛查结果为假阳性的女性患乳腺癌的风险更高。我们旨在评估排除误诊情况（即实际为假阴性而非假阳性的女性）后假阳性结果后患癌的额外风险。
我们使用了丹麦哥本哈根乳腺钼靶筛查项目的数据。研究人群为在1991 - 2005年筛查期间钼靶检查结果为假阳性且后来患乳腺癌的295名女性，她们来自总共58003名参与者中的4743名被召回的女性。对与最初导致召回的检查结果出现在同一位置发生的癌症进行了深入研究，以确定是否存在误诊。
发现72例存在误诊。排除误诊检查的女性后，与仅为阴性检查结果的女性相比，假阳性检查结果的女性患乳腺癌的额外风险为27%（风险比=1.27，95%置信区间（CI），1.11 - 1.46）。评估时确定为假阳性的女性额外风险为27%，而手术时确定为假阳性的女性额外风险为30%。
结果表明，风险增加并非仅由误诊所致。评估时以及手术时确定为假阳性的情况均存在额外风险，这表明存在某种生物学易感性。有必要对假阳性的真正额外风险进行进一步研究。
