Concurrent Use in Taiwan of Chinese Herbal Medicine Therapies among Hormone Users Aged 55 Years to 79 Years and Its Association with Breast Cancer Risk: A Population-Based Study
Table 3
Number (no.) of new cases, population-at-risk, hazard ratios (HR), and 95% confidence intervals (CI) for breast cancer estimated using the univariate Cox regression model on a random sample from the National Health Insurance Research Database among sample subjects and followed from 1997 to 2008.
Presence of breast cancer during the follow-up period
HT users who did use a Chinese medicine. Number of cases/population
HT users coprescribed a Chinese medicine, Number of cases/population
HT users coprescribed a Chinese medicine/HT users who did not use a Chinese medicine HR (95% CI)
HT* use at baseline
Estrogen-alone
Current users
3/53
2/117
0.30 (0.05–1.81)
Last use 1–3 years previously
0/211
3/249
—
Last use 4-5 years previously
1/192
1/157
1.21 (0.08–19.41)
Last use >=6 years previously
2/710
1/395
0.90 (0.08–9.91)
Progesterone-alone
Current users
3/9
0/0
—
Last use 1–3 years previously
0/23
0/0
—
Last use 4-5 years previously
0/19
0/0
—
Last use >=6 years previously
0/32
0/0
—
Estrogen and progesterone combination
Current users
0/0
0/0
—
Last use 1–3 years previously
0/0
0/0
—
Last use 4-5 years previously
0/0
0/0
—
Last use >=6 years previously
0/0
0/0
—
Mixed type†
Current users
5/69
7/246
0.39 (0.13–1.24)
Last use 1–3 years previously
1/69
8/192
2.87 (0.36–22.98)
Last use 4-5 years previously
0/118
0/614
—
Last use >=6 years previously
16/836
11/1,081
0.53 (0.25–1.15)
HT refers to hormonal therapy. †Mixed type refers to the estrogen-alone (E-alone); estrogen together with progesterone (E + P); other preparations, which included progesterone only and vaginal and other local treatments and combinations of the above preparation types.
