Lee Jihyoun, Lee Ji Sung, Lee Jong Eun, Kim Zisun, Han Sun Wook, Hur Sung Mo, Choi Young Jin, Park Sungmin
Department of Surgery, Soonchunhyang University Seoul Hospital, Seoul, Korea.
Clinical Research Center, Asan Institute for Life Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
J Breast Cancer. 2021 Jun;24(3):280-288. doi: 10.4048/jbc.2021.24.e28. Epub 2021 May 14.
Raloxifene is a selective estrogen receptor modulator (SERM), and raloxifene treatment for osteoporosis is reimbursable under the Korean National Health Insurance. Evidence suggests that SERMs use reduces the risk of breast cancer in Asian population. Herein, we retrospectively investigated the protective effect of raloxifene on breast cancer rates in Korean population.
Using the Health Insurance Review and Assessment Service database, we selected women with osteoporosis aged 50 years and above. Patients treated for at least 2 years with raloxifene were assigned to the user group, whereas the remaining patients were assigned to the non-user group. The effect on breast cancer risk was assessed using the Cox proportional-hazards model with a time-dependent covariate to adjust for immortal time bias.
A total of 322,870 women who were registered between 2010 and 2011 were included. The user group comprised 0.7% (n = 2,307) of the total population. The mean age was 65.7 ± 8.0 years and 67.2 ± 8.6 years in the user and non-user groups, respectively ( < 0.001). There was no difference in the previous use of estrogen replacement between the 2 groups ( = 0.087). The incidence of breast cancer per 1,000 person-years was 0.49 (n = 8) and 0.68 (n = 1,714) in the user and non-user groups, respectively (hazard ratio [HR], 0.63, 95% confidence interval [CI], 0.32-1.27). HR decreased with increase in the treatment duration, but this change was not statistically significant (HR, 1.00, 95% CI, 0.32-3.11 in 2-3 years; HR, 0.63, 95% CI, 0.20-1.94 in 3-4 years; and HR, 0.41, 95% CI, 0.10-1.65 in 4-5 years).
Long-term treatment with raloxifene in women with osteoporosis was not significantly associated with a reduction in breast cancer rates. However, further investigation is required for a conclusive proof.
雷洛昔芬是一种选择性雌激素受体调节剂（SERM），在韩国国民健康保险制度下，雷洛昔芬治疗骨质疏松症是可报销的。有证据表明，SERM的使用可降低亚洲人群患乳腺癌的风险。在此，我们回顾性研究了雷洛昔芬对韩国人群乳腺癌发病率的保护作用。
利用健康保险审查和评估服务数据库，我们选取了50岁及以上的骨质疏松症女性。接受雷洛昔芬治疗至少2年的患者被分配到使用组，而其余患者被分配到非使用组。使用Cox比例风险模型并采用时间依存性协变量来评估对乳腺癌风险的影响，以校正不朽时间偏倚。
共纳入了2010年至2011年期间登记的322,870名女性。使用组占总人口的0.7%（n = 2,307）。使用组和非使用组的平均年龄分别为65.7±8.0岁和67.2±8.6岁（P<0.001）。两组之间既往雌激素替代疗法的使用情况无差异（P = 0.087）。使用组和非使用组每1000人年的乳腺癌发病率分别为0.49（n = 8）和0.68（n = 1,714）（风险比[HR]，0.63，95%置信区间[CI]，0.32 - 1.27）。HR随着治疗持续时间的增加而降低，但这种变化无统计学意义（2 - 3年时HR，1.00，95%CI，0.32 - 3.11；3 - 4年时HR，0.63，95%CI，0.20 - 1.94；4 - 5年时HR，0.41，95%CI，0.10 - 1.65）。
骨质疏松症女性长期使用雷洛昔芬与乳腺癌发病率的降低无显著相关性。然而，需要进一步研究以得出确凿证据。
