Table 3: Summary of Evidence—Mammography Trials for Women Younger than 50 Years—Breast Cancer Mortality
| Study |
Age at entry (years) |
Screening interval (months) |
Year study began |
Total study sample size |
Breast cancer mortality at mid-range follow-up (6 to 8 years) |
Breast cancer mortality at 14-year follow-up |
| Study group |
Control group |
Study group |
Control group |
RR (95% CI) |
Study group |
Control group |
RR (95% CI) |
| HIP |
40–49 |
12 |
1963 |
13,740 |
13,740 |
19 |
20 |
0.95 (0.51–1.78) |
64 |
82 |
0.78 (0.56–1.08) |
| Malmö |
45–54 |
18–24 |
1976 |
13,568 |
12,279 |
N/A |
N/A |
N/A |
53 |
66 |
0.73 (0.51–1.04) |
| Östergötland (E-County) |
40–49 |
24 |
1977 |
10,285 |
10,459 |
15 |
15 |
1.03 (0.50–2.11) |
31 |
30 |
1.05 (0.64–1.73) |
| Kopparberg (W-County) |
40–49 |
24 |
1977 |
9,582 |
5,031 |
13 |
9 |
0.76 (0.32–1.77) |
22 |
16 |
0.72 (0.38–1.37) |
| CNBSS-1 |
40–49 |
12 |
1980 |
25,214 |
25,216 |
38 |
28 |
1.36 (0.84–2.21) |
105 |
108 |
0.97 (0.74–1.27) |
| Stockholm |
40–49 |
28 |
1981 |
14,303 |
8,021 |
16 |
8 |
1.09 (0.40–3.00) |
34 |
13 |
1.47 (0.77–2.78) |
| Göteborg |
39–49 |
18 |
1982 |
11,724 |
14,217 |
16 |
33 |
0.59 (0.33–1.06) |
34 |
59 |
0.70 (0.46–1.06) |
| UK AGE |
39–41 |
12 |
1991 |
53,884 |
106,956 |
26 |
65 |
0.79 (0.48–1.27) |
105 |
251 |
0.83 (0.66–1.04) |