Description of the study population
| BC, breast cancer | |
| *For specific mutations see table 2. | |
| †At the initiation of the study, the carrier status was known in 31 of the participating subjects. During the study all included subjects wanted to have a predictive genetic BRCA test, so that in the end we knew the carrier status of all participating subjects. | |
| ‡These statistics do not represent the actual cancer incidence, as only living individuals are included in this study. The BRCA1 mutation was carried by 36% of the subjects, BRCA2 by 46%, and 18% did not carry the familial BRCA1/2 mutation and were considered to be sporadic cancers. Of the subjects with ovarian cancer, 75% carried a BRCA1 mutation, and 25% a BRCA2 mutation. The only subject with breast and ovarian cancer carried a BRCA2 mutation. Of the subjects without breast or ovarian cancer, 19% carried a BRCA1 mutation, 19% had a BRCA2 mutation, and 62% did not carry a BRCA1/2 mutation. | |
| Number of participating families/subjects | 14/107 |
| Males/females | 44/63 |
| Minimum/maximum age of the subjects | 21 years/83 years |
| Relationship to the proband | 1st−4th degree (largest group 1st–3rd) |
| Families with a BRCA1/BRCA2 mutation* | 7/7 |
| No. of carriers of a BRCA1/BRCA2 mutation† | 23/22 |
| No. of non-carriers of a BRCA1/2 mutation† | 62 |
| Percentage of subjects with: | |
| no breast or ovarian cancer ‡ | 85.9% |
| breast cancer‡ | 10.3% (1.7% bilateral BC) |
| ovarian cancer‡ | 3.7% |
| breast and ovarian cancer‡ | 0.9% |