UNASSIGNED: Registry based, case-control study, nested in a nationwide cohort.
UNASSIGNED: Based in Denmark using the civil registration system, the national registry of medicinal product statistics, the Danish cancer registry, the Danish birth registry, and statistics Denmark.
UNASSIGNED: Women aged 50-60 years in year 2000 or turning 50 years during the study period of 1 January 2000 to 31 December 2018 were included. Exclusions were a history of cancer, mastectomy, use of systemic hormone treatment, use of the levonorgestrel releasing intrauterine system, or use of vaginal oestrogen treatments other than oestradiol tablets. To each woman who developed breast cancer during follow-up (18 997), five women in the control group (94 985) were incidence density matched by birth year.
UNASSIGNED: The main outcome was pathology confirmed breast cancer diagnosis.
UNASSIGNED: 2782 (14.6%) women with breast cancer (cases) and 14 999 (15.8%) women with no breast cancer diagnosis (controls) had been exposed to vaginal oestradiol tablets with 234 cases and 1232 controls having been in treatment for at least four years at a high intensity (>50 micrograms per week). Increasing durations and intensities of use (cumulative dose/cumulative duration) of vaginal oestradiol tablets was not associated with increasing rates of breast cancer. Compared with never-use, cumulative use of vaginal oestradiol for more than nine years was associated with an adjusted hazard ratio of 0.87 (95% confidence interval 0.69 to 1.11). Results were similar in women who had long term use (≥four years) and with high intensity of use (>50-70 micrograms per week) with an adjusted hazard ratio 0.93 (95% confidence interval 0.81 to 1.08).
UNASSIGNED: Use of vaginal oestradiol tablets was not associated with increased breast cancer rate compared with never-use. Increasing duration and intensity of use was not associated with increased rates of breast cancer.
■基于注册表,病例对照研究,嵌套在一个全国性的队列中。
■总部设在丹麦,采用民事登记制度,国家药品统计登记处,丹麦癌症登记处,丹麦出生登记处,和统计丹麦。
■纳入2000年50-60岁或2000年1月1日至2018年12月31日研究期间50岁的女性。排除是癌症史,乳房切除术,使用全身激素治疗,使用左炔诺孕酮宫内释放系统,或使用除雌二醇片以外的阴道雌激素治疗。对于每位在随访期间患乳腺癌的女性(18997),对照组中的5名妇女(94985)的发病率密度与出生年份相匹配。
■主要结果是病理证实的乳腺癌诊断。
■2782(14.6%)患有乳腺癌的女性(病例)和14999(15.8%)未诊断出乳腺癌的女性(对照)已暴露于阴道雌二醇片剂,其中234例和1232例对照已接受高强度治疗至少四年(每周>50微克)。阴道雌二醇片的使用持续时间和强度(累积剂量/累积持续时间)的增加与乳腺癌发病率的增加无关。与从不使用相比,累计使用阴道雌二醇超过9年与0.87的校正风险比相关(95%置信区间0.69~1.11).长期使用(≥4年)和高强度使用(每周>50-70微克)的女性的结果相似,调整后的风险比为0.93(95%置信区间为0.81至1.08)。
■与从未使用相比,使用阴道雌二醇片与乳腺癌发病率增加无关。持续时间和使用强度的增加与乳腺癌发病率的增加无关。