Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY, USA.
Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.
JNCI Cancer Spectr. 2021 Aug 31;5(4). doi: 10.1093/jncics/pkab072. eCollection 2021 Aug.
The effect of calcium plus vitamin D (CaD) supplementation on risk of ductal carcinoma in situ (DCIS) of the breast, a nonobligate precursor of invasive ductal carcinoma, is not well understood. In this secondary analysis, we examined this association in the Women's Health Initiative CaD trial over approximately 20 years of follow-up.
A total of 36 282 cancer-free postmenopausal women (50-79 years) were randomly assigned to daily (d) calcium (1000 mg) plus vitamin D (400 IU) supplementation or to a placebo. Personal supplementation with vitamin D (≤600 IU/d, subsequently raised to 1000 IU/d) and calcium (≤1000 mg/d) was allowed. The intervention phase (median = 7.1 years), was followed by a postintervention phase (additional 13.8 years), which included 86.0% of the surviving women. A total of 595 incident DCIS cases were ascertained. Hazard ratios (HRs) plus 95% confidence intervals (CIs) were calculated.
The intervention group had a lower risk of DCIS throughout follow-up (HR = 0.82, 95% CI = 0.70 to 0.96) and during the postintervention phase (HR = 0.76, 95% CI = 0.61 to 0.94). The group that used CaD personal supplements in combination with the trial intervention had a lower risk of DCIS compared with the trial placebo group that did not use personal supplementation (HR = 0.72, 95% CI = 0.56 to 0.91).
CaD supplementation in postmenopausal women was associated with reduced risk of DCIS, raising the possibility that consistent use of these supplements might provide long-term benefits for the prevention of DCIS.
钙加维生素 D（CaD）补充剂对乳腺导管原位癌（DCIS）风险的影响，乳腺导管原位癌是浸润性导管癌的非强制性前体，目前还不太清楚。在这项二次分析中，我们在 Women's Health Initiative CaD 试验中进行了大约 20 年的随访，研究了这种关联。
共有 36282 名无癌症的绝经后妇女（50-79 岁）被随机分配每天（d）服用钙（1000mg）加维生素 D（400IU）补充剂或安慰剂。允许个人补充维生素 D（≤600IU/d，随后提高到 1000IU/d）和钙（≤1000mg/d）。干预阶段（中位数=7.1 年）之后是干预后阶段（另外 13.8 年），其中包括 86.0%的幸存妇女。共确定了 595 例新发 DCIS 病例。计算了风险比（HR）加 95%置信区间（CI）。
在整个随访期间（HR=0.82，95%CI=0.70 至 0.96）和干预后阶段（HR=0.76，95%CI=0.61 至 0.94），干预组的 DCIS 风险较低。与未使用个人补充剂的试验安慰剂组相比，同时使用 CaD 个人补充剂和试验干预措施的组的 DCIS 风险较低（HR=0.72，95%CI=0.56 至 0.91）。
绝经后妇女补充钙加维生素 D 与降低 DCIS 风险相关，这表明长期使用这些补充剂可能对预防 DCIS 有长期益处。
