Table 1.
Hazard ratio estimates of RRSO for breast cancer from the prospective cohort studies by Domchek et al. (2) and Kauff et al. (3) among BRCA1/2 carrier women without prior breast or ovarian cancer and without prior RRSO/RRM
| Study | BRCA1 | BRCA2 | BRCA1/2 |
|---|---|---|---|
| Domchek et al. (2010), No. (%) | (n = 970) | (n = 597) | (n = 1567) |
| RRSO | |||
| Yes | 294 (30.3) | 155 (26.0) | 449 (28.7) |
| Cancer | 40 (13.6) | 13 (8.4) | 53 (11.8) |
| No | 676 (69.7) | 442 (74.0) | 1118 (71.3) |
| Cancer | 137 (20.3) | 96 (21.7) | 233 (20.8) |
| HR estimates (95% CI) and P value using the approach of Heemskerk-Gerritsen (1)* | 0.63(0.42 to 0.93)* P = .021 |
0.40(0.19 to 0.84)* P = .015 |
0.59(0.42 to 0.82)* P = .001 |
| HR estimates (95% CI) and P value using Domchek (2) original approach† | 0.56(0.39 to 0.81)* P = .002 |
0.42(0.21 to 0.86)* P = .02 |
0.51(0.36 to 0.70)* P = .001 |
| Kauff et al. (2008), No. (%) | (n = 220) | (n = 125) | (n = 345) |
| RRSO | |||
| Yes | 100 (45.5) | 60 (48) | 160 (46.4) |
| Cancer | 6 (6) | 2 (3.3) | 8 (5) |
| No | 120 (54.5) | 65 (52) | 185 (53.6) |
| Cancer | 11 (9.2) | 5 (7.7) | 16 (8.6) |
| HR estimates (95% CI) and P value using the approach of Heemskerk-Gerritsen (1)‡ | 0.47(0.16 to 1.37) P = .17 |
0.47(0.06 to 3.86) P = .49 |
0.50(0.20 to 1.25) P = .14 |
| Original HR estimates (95% CI) and P value in Kauff (3) | 0.61 (0.30 to 1.22) P = .16 |
0.28 (0.08 to 0.92) P = .036 |
0.53 (0.29 to 0.96) P = .036 |
* Age was used as the time scale with left truncation at the age of ascertainment in the Cox regression analyses. RRSO was used as a time-dependent variable that took value 0 before and 1 after RRSO. We stratified on study center and accounted for family correlation using robust variance estimates (7). All analyses adjusted for year of birth (<1940, 1940–49, 1950–59, 1960–69, ≥1970), parity (yes or no), and, in the analyses of combined carrier group, mutation status (BRCA1 or BRCA2). For BRCA2, year of birth was adjusted as whether born before 1960 or not. RRSO = risk-reducing salpingo-oophorectomy.
† This analysis used the same approach as Domchek et al. (2010). Time since age of RRSO was used for RRSO users, and time since ascertainment was used for non-RRSO users as time scale in Cox regression analyses. We stratified on study center and accounted for family correlation using robust variance estimates (7). All analyses adjusted for year of birth (whether born before 1960 or not).
‡ The analysis was the same as in the first note, except that follow-up started from age at genetic testing. Parity (yes or no) was adjusted for BRCA1, history of prior use of hormone replacement therapy (yes or no) for BRCA2, and both for the combined carrier group in addition to the mutation status.