Table 3.

Incidence rate of breast cancer − number of incident cases per 1,000 patient-years exposure to treatment with gonadal steroids

	Incident cases of breast cancer	Patient-years	Incidence rate	95% CI
Overall sample	2	2,282.5	0.88	0.11–3.17
				0.11–3.17
Group A	1	1,059	0.94	0.02–5.26
Group B	0	931.5	0	0–3.96
Group C	1	292	3.42	0.09–19.08