Table 1. Characteristics of the LHID2005 and BCOS Cohorts.
| Variable, Age Group | Osteoporosis Before Breast Cancer | P Valuea | |
|---|---|---|---|
| Yes | No | ||
| Women With Early-Stage Breast Cancer in the LHID2005 Cohort | |||
| Age at breast cancer diagnosis, mean (SD), y | |||
| Overall | 58.9 (13.1) | 45.7 (13.6) | <.001 |
| >55 y | 66.8 (9.2) | 64.0 (7.6) | <.001 |
| ≤55 y | 46.6 (7.8) | 40.4 (9.8) | <.001 |
| Radiation therapy, No./total No. (%) | |||
| Overall | 147/705 (20.9) | 1394/8399 (16.6) | .005 |
| >55 y | 97/429 (22.6) | 381/1890 (20.2) | .29 |
| ≤55 y | 50/276 (18.1) | 1013/6509 (15.6) | .29 |
| Chemotherapy, No./total No. (%) | |||
| Overall | 182/705 (25.8) | 1666/8399 (19.8) | <.001 |
| >55 y | 119/429 (27.7) | 491/1890 (26.0) | .49 |
| ≤55 y | 63/276 (22.8) | 1175/6509 (18.1) | .05 |
| Surgery, No./total No. (%) | |||
| Overall | 338/705 (47.9) | 2844/8399 (33.9) | <.001 |
| >55 y | 241/429 (56.2) | 944/1890 (49.9) | .02 |
| ≤55 y | 97/276 (35.1) | 1900/6509 (29.2) | .04 |
| Metastasis, No./total No. (%) | |||
| Bone | 27/705 (3.8) | 287/8399 (3.4) | .64 |
| Lung | 18/429 (4.2) | 230/1890 (12.2) | .07 |
| Liver | 14/276 (5.1) | 193/6509 (3.0) | .69 |
| Women With Early-Stage Breast Cancer in the BCOS Study Cohortb | |||
| Age at breast cancer diagnosis, mean (SD), y | |||
| Overall | 60.9 (11.7) | 57.0 (11.3) | <.001 |
| >55 y | 66.9 (9.1) | 66.0 (7.9) | <.001 |
| ≤55 y | 49.0 (5.3) | 47.9 (5.2) | <.001 |
| Radiation therapy, No./total No. (%) | |||
| Overall | 2886/14 020 (20.6) | 2788/15 163 (18.4) | <.001 |
| >55 y | 1974/9317 (21.2) | 1343/7645 (17.6) | <.001 |
| ≤55 y | 912/4703 (19.4) | 1445/7518 (19.2) | .83 |
| Chemotherapy, No./total No. (%) | |||
| Overall | 3423/14 020 (24.4) | 2986/15 163 (19.7) | <.001 |
| >55 y | 2363/9317 (25.4) | 1450/7645 (19.0) | <.001 |
| ≤55 y | 1060/4703 (22.5) | 1536/7518 (20.4) | .006 |
| Surgery, No./total No. (%) | |||
| Overall | 6648/14 020 (47.4) | 6020/15 163 (39.7) | <.001 |
| >55 y | 4913/9317 (52.7) | 3336/7645 (43.6) | <.001 |
| ≤55 y | 1735/4703 (36.9) | 2684/7518 (35.7) | .19 |
| Women in the BCOS Cohort Who Received Osteoporosis Therapy Before Breast Cancer Diagnosisc | |||
| Bisphosphonates | |||
| Age at breast cancer diagnosis, mean (SD), y | |||
| Overall | 73.0 (9.8) | 59.8 (11.6) | <.001 |
| >55 y | 74.1 (8.7) | 66.4 (8.9) | <.001 |
| ≤55 y | 51.3 (3.3) | 48.6 (5.5) | .05 |
| Radiation therapy, No./total No. (%) | 64/337 (19.0) | 2233/10 678 (20.9) | .43 |
| Chemotherapy, No./total No. (%) | 62/337 (18.4) | 2700/10 678 (25.3) | .005 |
| Surgery, No./total No. (%) | 167/337 (49.6) | 5047/10 678 (47.3) | .44 |
| Other osteoporosis drugs | |||
| Age at breast cancer diagnosis, mean (SD), y | |||
| Overall | 64.2 (10.6) | 59.8 (11.6) | <.001 |
| >55 y | 67.6 (9.2) | 66.4 (8.9) | <.001 |
| ≤55 y | 51.5 (3.2) | 48.6 (5.5) | <.001 |
| Radiation therapy, No./total No. (%) | 124/689 (18.0) | 2233/10 678 (20.9) | .07 |
| Chemotherapy, No./total No. (%) | 136/689 (19.7) | 2700/10 678 (25.3) | .001 |
| Surgery, No./total No. (%) | 301/689 (43.7) | 5047/ 10 678 (47.3) | .07 |
Abbreviations: BCOS, breast cancer and osteoporosis; LHID2005, Longitudinal Health Insurance Database 2005.
a
P values were derived from unpaired, 2-tailed t tests (age) or χ2 tests.
b
The group with no precancer osteoporosis in this cohort only includes women whose osteoporosis was diagnosed after the diagnosis of breast cancer and does not include those who never had a diagnosis of osteoporosis during the study period.
c
The definition of osteoporosis therapy is described in eMethods 3 in the Supplement.