Table 1.

Cancer detection by screening round in a trial of annual mammographic screening starting age 40, UK.

Screening round	Women screened1	Screen-detected cancers		ICs2 in the first 12 months		Mean age (years)	Mean screening interval (years)
		INV3	IS 4	INV3	IS 4
1	36 348	31	6	7	2	40.5	-
2	30 779	20	3	17	2	41.6	1.1
3	27 083	16	3	17	0	42.6	1.1
4	24 188	15	5	17	1	43.7	1.1
5	21 107	16	4	10	0	44.7	1.0
6	18 603	13	7	16	1	45.6	1.0
7	17 193	19	9	18	1	46.6	1.0
8	13 998	21	6	11	2	47.5	0.9
Total	189 299	151	43	113	9	43.4

¹Only includes women screened at all previous rounds; ²interval cancer; ³invasive carcinomas; ⁴in-situ carcinomas.