Lundell M, Mattsson A, Hakulinen T, Holm L E
Department of Hospital Physics, Karolinska Hospital, Stockholm, Sweden.
Radiat Res. 1996 Feb;145(2):225-30.
Between 1920 and 1959, 9675 women were irradiated in infancy for skin hemangioma at Radiumhemmet, Stockholm. They were exposed to low to moderate doses of ionizing radiation. The mean age at first exposure was 6 months and the mean absorbed dose to the breast anlage was 0.39 Gy (range <0.01-35.8 Gy). The breast cancer incidence was analyzed by record linkage with the Swedish Cancer Register for the period 1958-1986. Seventy-five breast cancers were found [standardized incidence ratio = 1.24; 95% confidence interval (CI) 0.98-1.54] after a mean absorbed dose of 1.5 Gy in the breasts with cancer. The analyses showed a significant dose-response relationship with a linear model estimate for the excess relative risk (ERR) of 0.38 at 1 Gy 95% CI 0.09-0.85). This relationship was not modified significantly by age at exposure or by dose to the ovaries. The ERR increased significantly with time after exposure and for > or = 50 years after exposure the ERR at 1 Gy was 2.25 (95% CI 0.59-5.62). The fitted excess absolute risk (EAR) was 22.9 per 10(4) breast-year gray. The breast absorbed dose and time after exposure were important risk determinants for breast cancer excess risk. Forty to 50 years of follow-up was necessary for the excess risk to be expressed. The study confirms previous findings that the breast anlage of female infants is sensitive to ionizing radiation.
1920年至1959年间，斯德哥尔摩镭疗中心对9675名女性在婴儿期进行了皮肤血管瘤放射治疗。她们接受了低至中等剂量的电离辐射。首次照射时的平均年龄为6个月，乳腺原基的平均吸收剂量为0.39 Gy（范围<0.01 - 35.8 Gy）。通过与瑞典癌症登记处进行记录链接，分析了1958年至1986年期间的乳腺癌发病率。在患癌乳房平均吸收剂量为1.5 Gy后，发现了75例乳腺癌[标准化发病率比 = 1.24；95%置信区间（CI）0.98 - 1.54]。分析显示存在显著的剂量 - 反应关系，线性模型估计1 Gy时的超额相对危险度（ERR）为0.38（95% CI 0.09 - 0.85）。这种关系在照射时的年龄或卵巢剂量方面未受到显著改变。ERR随照射后的时间显著增加，照射后≥50年时，1 Gy的ERR为2.25（95% CI 0.59 - 5.62）。拟合的超额绝对危险度（EAR）为每10⁴乳房 - 年戈瑞22.9。乳房吸收剂量和照射后的时间是乳腺癌超额风险的重要风险决定因素。需要40至50年的随访才能体现出超额风险。该研究证实了先前的发现，即女婴的乳腺原基对电离辐射敏感。
