Table 1.
Summary of subgroup analyses for early-life BMI and breast and ovarian cancer risks.
| Cancer site | Subgroups | Number of studies included | Summary RR (95% CI) | I2 | P-heterogeneity | ||
|---|---|---|---|---|---|---|---|
| Within subgroup | Between subgroups | ||||||
| Breast cancer | Tumour subtype | Oestrogen receptor-positive | 5 | 0.75 (0.65, 0.87) | 74.9% | 0.003 | 0.29 |
| Oestrogen receptor-negative | 3 | 0.60 (0.38, 0.98) | 77.5% | 0.01 | |||
| Age of BMI | BMI at age <18 | 7 | 0.87 (0.82, 0.91) | 77.8% | <0.001 | 0.63 | |
| BMI at age 18 | 10 | 0.79 (0.72, 0.87) | 58.4% | 0.01 | |||
| BMI at age >18 | 9 | 0.85 (0.79, 0.91) | 38.9% | 0.11 | |||
| BMI assessment method | Measured | 6 | 0.86 (0.80, 0.93) | 68.0% | 0.008 | 0.49 | |
| Self-reported | 20 | 0.83 (0.79, 0.87) | 60.4% | <0.001 | |||
| Region | USA | 12 | 0.82 (0.78, 0.87) | 59.1% | 0.005 | 0.45 | |
| Europe | 10 | 0.86 (0.82, 0.90) | 33.8% | 0.14 | |||
| Other | 4 | 0.81 (0.69, 0.96) | 79.2% | 0.002 | |||
| Ovarian cancer | Region | USA | 4 | 1.18 (1.05, 1.31) | 0.0% | 0.66 | 0.57 |
| Europe | 3 | 1.11 (0.97, 1.27) | 33.8% | 0.22 | |||
This table shows the results from subgroup analyses by tumour subtype, age of BMI, BMI assessment method, and region.
BMI body mass index, CI confidence interval, RR relative risk.