Boyd Norman F, Guo Helen, Martin Lisa J, Sun Limei, Stone Jennifer, Fishell Eve, Jong Roberta A, Hislop Greg, Chiarelli Anna, Minkin Salomon, Yaffe Martin J
Campbell Family Institute for Breast Cancer Research, Toronto, ON, Canada.
N Engl J Med. 2007 Jan 18;356(3):227-36. doi: 10.1056/NEJMoa062790.
Extensive mammographic density is associated with an increased risk of breast cancer and makes the detection of cancer by mammography difficult, but the influence of density on risk according to method of cancer detection is unknown.
We carried out three nested case-control studies in screened populations with 1112 matched case-control pairs. We examined the association of the measured percentage of density in the baseline mammogram with risk of breast cancer, according to method of cancer detection, time since the initiation of screening, and age.
As compared with women with density in less than 10% of the mammogram, women with density in 75% or more had an increased risk of breast cancer (odds ratio, 4.7; 95% confidence interval [CI], 3.0 to 7.4), whether detected by screening (odds ratio, 3.5; 95% CI, 2.0 to 6.2) or less than 12 months after a negative screening examination (odds ratio, 17.8; 95% CI, 4.8 to 65.9). Increased risk of breast cancer, whether detected by screening or other means, persisted for at least 8 years after study entry and was greater in younger than in older women. For women younger than the median age of 56 years, 26% of all breast cancers and 50% of cancers detected less than 12 months after a negative screening test were attributable to density in 50% or more of the mammogram.
Extensive mammographic density is strongly associated with the risk of breast cancer detected by screening or between screening tests. A substantial fraction of breast cancers can be attributed to this risk factor.
乳腺钼靶摄影显示的广泛致密影与乳腺癌风险增加相关，且会使通过钼靶摄影检测癌症变得困难，但致密影对癌症检测方法相关风险的影响尚不清楚。
我们在接受筛查的人群中开展了三项嵌套病例对照研究，共有1112对匹配的病例对照。我们根据癌症检测方法、筛查开始后的时间以及年龄，研究了基线钼靶片中测得的致密影百分比与乳腺癌风险之间的关联。
与钼靶片中致密影占比小于10%的女性相比，致密影占比75%或更高的女性患乳腺癌的风险增加（比值比为4.7；95%置信区间[CI]为3.0至7.4），无论癌症是通过筛查检测到的（比值比为3.5；95%CI为2.0至6.2），还是在阴性筛查检查后不到12个月内检测到的（比值比为17.8；95%CI为4.8至65.9）。无论癌症是通过筛查还是其他方式检测到的，患乳腺癌风险增加在研究入组后至少持续8年，且年轻女性比年长女性更大。对于年龄小于56岁中位数的女性，所有乳腺癌中的26%以及在阴性筛查检查后不到12个月内检测到的癌症中的50%可归因于钼靶片中50%或更多的致密影。
乳腺钼靶摄影显示的广泛致密影与通过筛查或两次筛查之间检测到的乳腺癌风险密切相关。相当一部分乳腺癌可归因于这一风险因素。
