Table 3. Incidence rates of breast cancer per 100 000 women-years for female cancer survivorsa according to age and stage of breast cancer (second primary) in 1970s and 1990s.

	1970s		1990s
Period of first primary cancer diagnosis	60.8		63.2
Mean age at breast cancer (years)	N	Incidence (100 000)	N	Incidence (100 000)	Rate ratiob	(95% CI)
Age at breast cancer (second primary – age-specific rates)
30–49 years	23	678	43	887	1.3	0.8–2.2
50–74 years	61	509	94	615	1.2	0.9–1.7
75+	16	409	45	664	1.6	0.9–2.9
Stage of breast cancer (second primary) c
I	41	209	82	305	1.46	0.99–2.11
II	13	68	57	212	3.10	1.73–5.78
III	11	58	18	67	1.16	0.56–2.50
IV	9	46	14	52	1.14	0.50–2.65
Unknown	26	140	11	41	0.29	0.14–0.59

N indicates number of cases.

^aFemale cancer survivors are both breast cancer and non-breast cancer survivors.

^bRate ratio compares incidence rate in 1990s with incidence rate in 1970s, if adjusted rates are presented than rate ratio is based on the standardised rates.

^cAge adjusted.