Hill Deirdre A, Preston-Martin Susan, Ross Ronald K, Bernstein Leslie
Department of Preventive Medicine, University of Southern California, Keck School of Medicine, Norris Comprehensive Cancer Center, Los Angeles 90033, USA.
Cancer Causes Control. 2002 Oct;13(8):711-8. doi: 10.1023/a:1020201106117.
In previous studies breast cancer risk has been increased among women who received high doses (above 100-200 cGy) of ionizing radiation or those exposed to lower doses prior to age 20. Some evidence suggests that such risk may be distinctly elevated among women with a family history of breast or ovarian cancer (probably only carriers of specific gene mutations) and women with benign breast disease (BBD).
A population-based case-control study in Los Angeles County obtained interview data from 744 women who were aged 40 or younger and diagnosed with breast cancer during 1983-1988, and from 744 matched controls. Women with a positive family history of breast or ovarian cancer reported cancer in a mother, sister, or grandmother. Women with BBD reported a physician diagnosis. Radiation exposure was defined as a history of either radiation therapy or moderate exposure to medical radiography.
Breast cancer risk was elevated among women exposed to medical radiation prior to age 20 years (odds ratio (OR) = 1.4, 95% confidence interval (CI) = 1.2-1.8), relative to unexposed women. This increased risk was observed only among women with a history of BBD (OR = 2.4, 95% CI = 1.6-3.7). Overall, risk was not associated with exposure to medical radiation after age 20 years, although among women with a positive family history of breast or ovarian cancer, exposed women had an increased risk (OR= 1.8, 95% CI = 1.0-3.1). Breast cancer risk was not increased among women with a family history of breast/ovarian cancer exposed to medical radiation before age 20 years or those with BBD exposed to medical radiation after age 20 years.
Study participants may have received radiation doses that are no longer common, hampering study generalizability. Although differences in recall between cases and controls cannot be completely excluded, women with BBD or a family history of breast cancer appear to have greater breast cancer risk following relatively low ionizing radiation exposure than other women in this study.
在先前的研究中，接受高剂量（超过100 - 200厘戈瑞）电离辐射的女性，或20岁之前接受较低剂量辐射的女性患乳腺癌的风险有所增加。一些证据表明，在有乳腺癌或卵巢癌家族史（可能仅为特定基因突变携带者）的女性以及患有良性乳腺疾病（BBD）的女性中，这种风险可能会明显升高。
在洛杉矶县进行的一项基于人群的病例对照研究，收集了744名年龄在40岁及以下、在1983 - 1988年期间被诊断为乳腺癌的女性以及744名匹配对照的访谈数据。有乳腺癌或卵巢癌家族史阳性的女性报告其母亲、姐妹或祖母患有癌症。患有BBD的女性报告有医生诊断。辐射暴露定义为有放射治疗史或中度接受医学放射成像检查。
与未暴露女性相比，20岁之前接受医学辐射的女性患乳腺癌的风险升高（比值比（OR）= 1.4，95%置信区间（CI）= 1.2 - 1.8）。这种风险增加仅在有BBD病史的女性中观察到（OR = 2.4，95% CI = 1.6 - 3.7）。总体而言，20岁之后的医学辐射暴露与风险无关，尽管在有乳腺癌或卵巢癌家族史阳性的女性中，暴露女性的风险增加（OR = 1.8，95% CI = 1.0 - 3.1）。20岁之前接受医学辐射且有乳腺癌/卵巢癌家族史的女性，或20岁之后接受医学辐射且患有BBD的女性，患乳腺癌的风险并未增加。
研究参与者可能接受了如今已不常见的辐射剂量，这妨碍了研究的可推广性。尽管不能完全排除病例组和对照组在回忆方面的差异，但在本研究中，患有BBD或有乳腺癌家族史的女性在相对低剂量的电离辐射暴露后，似乎比其他女性有更高的患乳腺癌风险。
