Table 4. Effect of breastfeeding on women's risk of breast and ovarian cancer, UK 2008.

	Breast cancer				Ovarian cancer
	1	2	3	4	1	2	3	4
Age (years)	Estimated individual decrease in risk	Target decrease in risk a	Excess risk	PAF (%)	Estimated individual decrease in risk	Target decrease in risk a	Excess risk	PAF (%)
0–4	—	—	0	—	—	—	0	—
5–9	—	—	0	—	—	—	0	—
10–14	—	—	0	—	—	—	0	—
15–19	0.0005	0.0010	0.001	0.1	0.0026	0.0052	0.003	0.3
20–24	0.0043	0.0086	0.004	0.4	0.0219	0.0443	0.022	2.3
25–29	0.0084	0.0196	0.011	1.1	0.0429	0.1010	0.058	6.1
30–34	0.0140	0.0328	0.019	1.9	0.0718	0.1691	0.097	10.5
35–39	0.0183	0.0429	0.025	2.5	0.0935	0.2212	0.128	14.1
40–44	0.0186	0.0463	0.028	2.8	0.0951	0.2387	0.144	15.9
45–49	0.0195	0.0478	0.028	2.9	0.0997	0.2466	0.147	16.3
50–54	0.0207	0.0495	0.029	2.9	0.1060	0.2550	0.149	16.7
55–59	0.0209	0.0500	0.029	3.0	0.1071	0.2575	0.150	16.8
60–64	0.0225	0.0536	0.031	3.2	0.1149	0.2764	0.161	18.2
65–69	0.0240	0.0573	0.033	3.4	0.1228	0.2953	0.173	19.7
70v74	0.0246	0.0588	0.034	3.5	0.1260	0.3029	0.177	20.2
75–79	0.0241	0.0576	0.033	3.4	0.1233	0.2966	0.173	19.8
80–84	0.0217	0.0519	0.030	3.1	0.1113	0.2676	0.156	17.6
⩾85	0.0205	0.0490	0.028	2.9	0.1050	0.2524	0.147	16.5

Abbreviation: PAF=population-attributable fraction.

^aIf all had breastfed for a minimum of 6 months.