2. Comparison on 15-year cumulative survival rates between early-stage breast cancer cohorts with and without mammographic screening.

Age (year)	1973−1976 early-stage cancer cohort (no screening)				1999 early-stage cancer cohort (screening)			Improvement on survival rate (%)	P
	Total number	Number of death	Cumulatively survival rate (%)		Total number	Number of death	Cumulatively survival rate (%)
40−49	3,493	854	75.4		2,853	325	88.4	13.0	<0.001
50−59	4,561	1,451	68.0		3,957	632	83.9	15.8	<0.001
60−69	4,041	2,000	50.4		3,529	1,125	67.8	17.4	<0.001
70−74	1,709	1,179	30.9		1,990	1,038	47.5	16.6	<0.001
≥75	3,087	2,747	10.9		3,692	2,992	18.6	7.7	<0.001
Total	16,891	8,231	51.1		16,021	6,112	61.5	10.4	<0.001
50−74 in total	10,311	4,630	55.0		9,476	2,795	70.2	15.3	<0.001