Table 2. Rates of granddaughter cancer in grandmother-granddaughter pairs.
| Registry women with exactly 1 grandmother with ovarian cancer |
|||
|---|---|---|---|
| Mother’s Mother | Father’s Mother | ||
| All Complete Pairs | |||
| Observed Pairs | 663 | 229 | |
| Granddaughter Cancer | 92 | 65 | |
| Cancer Rate | 13.9% | 28.4% | RR = 2.04 |
| (95% CI) | (11.4–16.8%) | (22.8–34.8%) | (1.55–2.71) |
| Expected # Cancers | |||
| Autosomal Dominant | 116.7 | 40.3 | X2 = 20.3, p<0.001 |
| X-linked Dominant | 92.5 | 63.9 | X2 = 0.02, p = 0.89 |
| Probands Excluded | |||
| Observed Pairs | 374 | 133 | |
| Granddaughter Cancer | 36 | 26 | |
| Cancer Rate | 9.6% | 19.5% | RR = 2.03 |
| (95% CI) | (6.9%-13.2%) | (13.4%-27.5%) | (1.28–3.23) |
| Granddaughter ≥ 45 Yearsa | |||
| Observed Pairs | 344 | 154 | |
| Granddaughter Cancer | 92 | 65 | |
| Cancer Rate | 26.7% | 42.2% | RR = 1.58 |
| (95% CI) | (22.2–31.8%) | (34.4–50.4%) | (1.22–2.04) |
| Site-specific Ovary Family | |||
| Observed Pairs | 291 | 127 | |
| Granddaughter Cancer | 49 | 44 | |
| Cancer Rate | 16.8% | 34.6% | RR = 2.06 |
| (95% CI) | (12.8–21.8%) | (26.6–43.7%) | (1.45–2.92) |
| Breast and Ovary Family | |||
| Observed Pairs | 357 | 89 | |
| Granddaughter Cancer | 43 | 21 | |
| Cancer Rate | 12.0% | 23.6% | RR = 1.96 |
| (95% CI) | (8.9–16.0%) | (15.5–34.0%) | (1.23–3.13) |
RR, Relative risk; X2, Chi-square goodness of fit statistic.
a Granddaughters without cancer who are younger than 45 are omitted