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 mortalityiii at mid-range follow-up (6 to 8 years) Breast cancer mortalityiii at 14-year follow-up
Study groupStudy group Control groupControl group Study groupStudy group Control groupControl group RR (95% CI)RR (95% CI) Study groupStudy group Control groupControl group RR (95% CI)RR (95% CI)
Study groupHIP66 Control group40–49 Study group12 Control group1963 RR (95% CI)13,740 Study group13,740 Control group19 RR (95% CI)Breast cancer mortalityiii at mid-range follow-up (6 to 8 years)20 0.95 (0.51–1.78) Breast cancer mortalityiii at 14-year follow-up64 Breast cancer mortalityiii at 14-year follow-up82 Breast cancer mortalityiii at 14-year follow-up0.78 (0.56–1.08)
Study groupMalmö58 Control group45–54 Study group18–24 Control group1976 RR (95% CI)13,568 Study group12,279 Control groupN/A RR (95% CI)Breast cancer mortalityiii at mid-range follow-up (6 to 8 years)N/A N/A Breast cancer mortalityiii at 14-year follow-up53 Breast cancer mortalityiii at 14-year follow-up66 Breast cancer mortalityiii at 14-year follow-up0.73 (0.51–1.04)
Study groupÖstergötland (E-County)65 Control group40–49 Study group24 Control group1977 RR (95% CI)10,285 Study group10,459 Control group15 RR (95% CI)Breast cancer mortalityiii at mid-range follow-up (6 to 8 years)15 1.03 (0.50–2.11) Breast cancer mortalityiii at 14-year follow-up31 Breast cancer mortalityiii at 14-year follow-up30 Breast cancer mortalityiii at 14-year follow-up1.05 (0.64–1.73)
Study groupKopparberg (W-County)65 Control group40–49 Study group24 Control group1977 RR (95% CI)9,582 Study group5,031 Control group13 RR (95% CI)Breast cancer mortalityiii at mid-range follow-up (6 to 8 years)9 0.76 (0.32–1.77) Breast cancer mortalityiii at 14-year follow-up22 Breast cancer mortalityiii at 14-year follow-up16 Breast cancer mortalityiii at 14-year follow-up0.72 (0.38–1.37)
Study groupCNBSS-156 Control group40–49 Study group12 Control group1980 RR (95% CI)25,214 Study group25,216 Control group38 RR (95% CI)Breast cancer mortalityiii at mid-range follow-up (6 to 8 years)28 1.36 (0.84–2.21) Breast cancer mortalityiii at 14-year follow-up105 Breast cancer mortalityiii at 14-year follow-up108 Breast cancer mortalityiii at 14-year follow-up0.97 (0.74–1.27)
Study groupStockholm64 Control group40–49 Study group28 Control group1981 RR (95% CI)14,303 Study group8,021 Control group16 RR (95% CI)Breast cancer mortalityiii at mid-range follow-up (6 to 8 years)8 1.09 (0.40–3.00) Breast cancer mortalityiii at 14-year follow-up34 Breast cancer mortalityiii at 14-year follow-up13 Breast cancer mortalityiii at 14-year follow-up1.47 (0.77–2.78)
Study groupGöteborg63 Control group39–49 Study group18 Control group1982 RR (95% CI)11,724 Study group14,217 Control group16 RR (95% CI)Breast cancer mortalityiii at mid-range follow-up (6 to 8 years)33 0.59 (0.33–1.06) Breast cancer mortalityiii at 14-year follow-up34 Breast cancer mortalityiii at 14-year follow-up59 Breast cancer mortalityiii at 14-year follow-up0.70 (0.46–1.06)
Study groupUK AGE61 Control group39–41 Study group12 Control group1991 RR (95% CI)53,884 Study group106,956 Control group26 RR (95% CI)Breast cancer mortalityiii at mid-range follow-up (6 to 8 years)65 0.79 (0.48–1.27) Breast cancer mortalityiii at 14-year follow-up105 Breast cancer mortalityiii at 14-year follow-up251 Breast cancer mortalityiii at 14-year follow-up0.83 (0.66–1.04)