Table 2. Estimates of Recurrence According to BMI at Breast Cancer Diagnosis.
| Body composition | Patients, No. | Person-years | Recurrences, No. | Crude hazard ratio (95% CI) | Adjusted hazard ratio (95% CI)a |
|---|---|---|---|---|---|
| Underweight, BMI <18.5 | 296 | 1561 | 28 | 1.06 (0.73-1.55) | 1.12 (0.77-1.64) |
| Healthy weight, BMI 18.5-24.9 | 5873 | 33 117 | 569 | 1 [Reference] | 1 [Reference] |
| Overweight, BMI 25.0-29.9 | 4294 | 23 995 | 471 | 1.16 (1.02-1.31) | 1.10 (0.97-1.24) |
| Obesity, BMI 30.0-34.9 | 1909 | 10 518 | 233 | 1.31 (1.12-1.52) | 1.18 (1.01-1.37) |
| Severe obesity, BMI ≥35.0 | 858 | 4654 | 110 | 1.40 (1.14-1.72) | 1.32 (1.08-1.62) |
| Total | 13 230 | 73 904 | 1587 | NA | NA |
Abbreviations: BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); NA, not applicable.
a
Adjusted for age at diagnosis, tumor size, Charlson Comorbidity Index, node status, histological grade, ERBB2 status, surgical procedure, chemotherapy, and radiotherapy.