Table 5.
Comparison of Expected With Observed Numbers of Invasive Breast Cancers Among White Women in the NIH-AARP and PLCO Studies Using an Updated Model on the Basis of 1995-2003 SEER Breast Cancer Incidence Rates
| Variable | NIH-AARP |
PLCO |
||||||
|---|---|---|---|---|---|---|---|---|
| Observed* | Expected† | Expected:Observed |
Observed* | Expected† | Expected:Observed |
|||
| Ratio | 95% CI | Ratio | 95% CI | |||||
| Overall | 5,665 | 5,810.4 | 1.03 | 1.00 to 1.05 | 2,223 | 2,250.2 | 1.01 | 0.97 to 1.06 |
| Age at menarche, years | ||||||||
| 7-11 | 1,253 | 1,349.9 | 1.08 | 1.02 to 1.14 | 487 | 483.5 | 0.99 | 0.91 to 1.08 |
| 12-13 | 3,180 | 3,233.6 | 1.02 | 0.98 to 1.05 | 1,169 | 1,223.0 | 1.05 | 0.99 to 1.11 |
| ≥14 | 1,223 | 1,213.9 | 0.99 | 0.94 to 1.05 | 565 | 539.3 | 0.95 | 0.88 to 1.04 |
| No. of first-degree relatives with breast cancer and age at first birth < 20 years | ||||||||
| 0 | 619 | 532.9 | 0.86 | 0.80 to 0.93 | 225 | 192.6 | 0.86 | 0.75 to 0.98 |
| 1 | 126 | 202.9 | 1.61 | 1.35 to 1.92 | 47 | 72.3 | 1.54 | 1.16 to 2.05 |
| ≥ 2 | 3 | 27.4 | 9.12 | 2.94 to 28.28 | 6 | 19.6 | 3.26 | 1.47 to 7.26 |
| No. of first-degree relatives with breast cancer and age at first birth 20-24 years | ||||||||
| 0 | 1,859 | 1,772.1 | 0.95 | 0.91 to 1.00 | 803 | 733.8 | 0.91 | 0.85 to 0.98 |
| 1 | 427 | 555.9 | 1.30 | 1.18 to 1.43 | 178 | 231.5 | 1.30 | 1.12 to 1.51 |
| ≥ 2 | 35 | 66.2 | 1.89 | 1.36 to 2.63 | 31 | 51.3 | 1.65 | 1.16 to 2.35 |
| No. of first-degree relatives with breast cancer and age at first birth 25-29 years or nulliparous | ||||||||
| 0 | 1,586 | 1,569.7 | 0.99 | 0.94 to 1.04 | 594 | 555.2 | 0.93 | 0.86 to 1.01 |
| 1 | 347 | 409.3 | 1.18 | 1.06 to 1.31 | 105 | 150.4 | 1.43 | 1.18 to 1.73 |
| ≥ 2 | 33 | 38.6 | 1.17 | 0.83 to 1.65 | 16 | 22.9 | 1.43 | 0.88 to 2.33 |
| No. of first-degree relatives with breast cancer and age at first birth ≥ 30 years | ||||||||
| 0 | 320 | 343.7 | 1.07 | 0.96 to 1.2 | 165 | 162.5 | 0.98 | 0.85 to 1.15 |
| 1 | 59 | 73.6 | 1.25 | 0.97 to 1.61 | 24 | 33.0 | 1.37 | 0.92 to 2.05 |
| ≥ 2 | 2 | 5.9 | 2.94 | 0.74 to 11.77 | 3 | 5.1 | 1.69 | 0.55 to 5.24 |
| No. of breast biopsies | ||||||||
| 0 | 3,855 | 3,953.3 | 1.03 | 0.99 to 1.06 | ||||
| 1 | 1,134 | 1,089.2 | 0.96 | 0.91 to 1.02 | ||||
| ≥ 2 | 661 | 748.3 | 1.13 | 1.05 to 1.22 | ||||
Abbreviations: NIH-AARP, National Institutes of Health–AARP Diet and Health Study; PLCO, Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial; SEER, Surveillance, Epidemiology, and End Results.
*
Observed number of invasive breast cancers. Separate category for unknown for each factor not shown because of small numbers.
†
Expected number of invasive breast cancers from the recalibrated Gail model on the basis of 1995-2003 SEER breast cancer incidence rates.