Table 1.
Characteristics of women at study entry, 2005–2015 (n = 295 087)
| Characteristics | Full cohort |
Incident cancer diagnosis during study period |
||
|---|---|---|---|---|
| Total | None | Breast cancer | Ovarian cancer | |
| No. (%) | No. (%) | No. (%) | No. (%) | |
| Total No. | 295 087 | 290 805 | 3992 | 290 |
| Mean person-time (SD), y | 4.5 (3.8) | 4.5 (3.8) | 4.5 (3.1) | 4.3 (3.0) |
| Mean age (SD), y | 43.6 (17.9) | 43.4 (17.8) | 58.7 (12.5) | 61.6 (13.1) |
| Age group, y | ||||
| 18–29 | 79 609 (27.0) | 79 582 (27.4) | 23 (0.6) | 4 (1.4) |
| 30–49 | 105 278 (35.7) | 104 324 (35.9) | 907 (22.7) | 47 (16.2) |
| 50–69 | 84 300 (28.5) | 81 859 (28.1) | 2284 (57.2) | 160 (55.2) |
| ≥70 | 25 900 (8.8) | 25 040 (8.6) | 907 (22.7) | 47 (16.2) |
| Race/ethnicity | ||||
| Hispanic | 14 364 (4.9) | 14 106 (4.9) | 244 (6.1) | 14 (4.8) |
| White | 177 480 (60.1) | 174 052 (59.9) | 3182 (79.7) | 246 (84.8) |
| Asian | 27 230 (9.2) | 26 920 (9.3) | 293 (7.4) | 17 (5.9) |
| Black | 13 204 (4.5) | 13 068 (4.5) | 133 (3.3) | 3 (1.0) |
| Other* | 10 487 (3.6) | 10 339 (3.6) | 138 (3.5) | 10 (3.5) |
| Missing | 52 322 (17.7) | 52 320 (18.0) | 2 (0.1) | 0 (0.0) |
| Prior breast cancer | 5689 (1.9) | 5283 (1.8) | 388 (9.7) | 18 (6.2) |
| Prior breast cancer before age 50 years | 923 (0.3) | 851 (0.3) | 72 (1.8) | 0 (0.0) |
| FH indicating HBOC risk | ||||
| No | 75 616 (25.6) | 73 239 (25.2) | 2218 (55.6) | 159 (54.8) |
| Yes | 10 314 (3.5) | 9819 (3.4) | 464 (11.6) | 31 (10.7) |
| Missing | 209 157 (70.9) | 207 747 (71.4) | 1310 (32.8) | 100 (34.5) |
| Length of health plan enrollment, y | ||||
| 1–2 | 70 221 (23.8) | 70 150 (24.1) | 66 (1.7) | 5 (1.7) |
| 3–5 | 62 935 (21.3) | 62 679 (21.6) | 235 (5.9) | 21 (7.2) |
| 6–10 | 52 271 (17.7) | 51 722 (17.8) | 504 (12.6) | 45 (15.5) |
| ≥11 | 109 660 (37.2) | 106 254 (36.5) | 3187 (79.8) | 219 (75.5) |
*Includes individuals who identified as American Indian, Alaskan Native, Native Hawaiian, Pacific Islander, and multiple race or ethnicity categories. FH = family history; HBOC = hereditary breast and ovarian cancer.