Table 2.

Breast cancer risk and radiation exposure: baseline depends on city, in-city status, age ATB, and attained age

Overall: all reproductive status categories combined
Dose category (Gy)SubjectsPerson yearsCasesRR (95% CI)*
<0.00514,830443,9662611.00 (Reference)
0.005-0.4913,075397,3452661.19 (1.00, 1.49)
0.50-0.991,24336,102542.42 (1.70-3.43)
1.00-1.9967018,968403.33 (2.19-5.00)
≥2.002957,694204.33 (2.61-6.08)
ERR per Gy (e = 30, a = 70)1.55 (0.87-2.42)
Age at exposure (% Δ/10-y increase)−3% (−31 to −36%)
Attained age (power)−0.78 (−2.4 to −0.9)
EAR per Gy (e = 30, a = 70)12.64 (8.18-17.72)
Age at exposure (% Δ/10-y increase)−43% (−57 to 26%)
Attained age (power)2.8 (1.7-3.9)
  • *95% CI calculated from the profile likelihood for hazard ratios and ERR and EAR per Gy terms and from Wald's method for age at exposure and attained age terms.