Table 1 Relative risk (95% CI) of breast cancer, observed in a Danish cohort of women aged 15–49 years and without a history of cancer, venous thromboembolism or fertility treatment [64]
From: Progesterone from ovulatory menstrual cycles is an important cause of breast cancer
(a) Relative risk according to time since use and duration of any type of hormonal contraception | |||
|---|---|---|---|
Duration of use | Relative risk of breast cancer (95% CI) | ||
 < 1 yr since recent use | 1 to < 5 yr since recent use | 5–10 yr since recent use | |
 < 1 yr | 0.96 (0.78–1.19) | 0.96 (0.85–1.09) | 1.01 (0.88–1.15) |
1 to < 5 yr | 1.04 (0.88–1.23) | 1.06 (0.96–1.18) | 1.07 (0.94–1.20) |
5–10 yr | 1.33 (1.11–1.59) | 1.16 (1.02–1.33) | 1.30 (1.06–1.58) |
 > 10 yr | 1.52 (1.17–1.98) | 1.16 (0.89–1.49) | NA |
(b) Relative risk among women using current or recent P-only contraception | ||
|---|---|---|
Current or recent P-only contraception | Relative risk (95% CI) | |
Oral contraception | NETA | 1.00 (0.80–1.25) |
LNG | 1.93 (1.18–3.16) | |
DSG | 1.18 (0.87–1.60) | |
Intra-uterine device | LNG | 1.21 (1.11–1.33) |