Table 2.
Characteristics of the cohort of BRCA1 and BRCA2 mutation carriers
| BRCA1 mutation carriers | BRCA2 mutation carriers | |||
|---|---|---|---|---|
| Unaffected women (N = 2003) | Women with breast cancer (N = 269) | Unaffected women (N = 1448) | Women with breast cancer (N = 157) | |
| Total person-years of follow-up | 11,207 | 1134 | 7286 | 600 |
| Person-years of follow-up (mean (sd)) | 5.60 (3.67) | 4.21 (3.27) | 5.03 (3.44) | 3.82 (3.08) |
| Age at start of follow-up (mean (sd)) | 37.51 (11.80) | 40.68 (10.25) | 40.00 (12.53) | 45.14 (10.11) |
| Age at diagnosis/censoring (mean (sd)) | 43.10 (12.28) | 44.90 (10.33) | 45.00 (13.00) | 48.97 (10.30) |
| Reason for censoring | ||||
| Breast cancer | 0 | 269 | 0 | 157 |
| Ovarian cancer | 49 | 3a | 9 | 1a |
| Other cancer | 45 | 5a | 28 | 2a |
| RRM | 299 | – | 181 | – |
| Death | 5 | – | 8 | – |
| Unaffected at last follow-up time | 1605 | – | 1222 | – |
| Year of birth | ||||
| ≤ 1960 | 604 (83.54) | 119 (16.46) | 500 (84.75) | 90 (15.25) |
| > 1960 | 1399 (90.32) | 150 (9.68) | 948 (93.40) | 67 (6.60) |
| Menopausal status | ||||
| Premenopausal at censoringb | ||||
| Last informationc after censoring | 512 | 69 | 344 | 35 |
| Last information before censoringd | 585 | 58 | 473 | 35 |
| Postmenopausal | ||||
| Natural menopause age known | 194 | 27 | 182 | 31 |
| Natural menopause age unknown | 5 | 0 | 7 | 1 |
| Post-hysterectomy | 70 | 12 | 64 | 11 |
| Unknown menopausal status | 62 | 13 | 33 | 8 |
| RRSO status at censoring | ||||
| No RRSO | ||||
| Last information after censoring | 664 | 110 | 467 | 79 |
| Last information before censoring | 618 | 44 | 535 | 27 |
| RRSO | 721 | 115 | 446 | 51 |
| As reason for menopausee | 574 | 90 | 345 | 36 |
| After natural menopause | 101 | 18 | 76 | 10 |
| After hysterectomy | 46 | 7 | 25 | 5 |
RRSO risk-reducing salpingo-oophorectomy, RRM risk-reducing mastectomy
aDiagnosed at the same time as breast cancer
bFifteen women did not report age at menopause but were older than 60 years at the end of follow-up
cInformation from questionnaire and record linkage
dAge last known to be premenopausal mean 32.3 years, median 31 years for BRCA1 mutation carriers: mean 33.9, median 34 years for BRCA2 mutation carriers. Time between this age and end of censoring: mean 6.3, median 5 years for BRCA1 and mean 6 years, median 5 years for BRCA2 mutation carriers
eSeven women reported RRSO after age 60 years without first reporting natural menopause