Sunnybrook Odette Cancer Centre, University of Toronto, Toronto, ON, Canada
Sherry Athena Doroja Ruste , Andrea Eisen , Kathleen I. Pritchard
Background: Publicly funded testing for BRCA1/2 mutations in Ontario has been available for high-risk individuals since 2000. The criteria are based on personal and/or family cancer history and ethnicity. We reviewed the results of the first 10 yrs of testing at our institution, a regional cancer centre in an academic, tertiary care teaching hospital. Methods: This REB-approved, retrospective study included individuals who had GT from 2001-2011. Sociodemographic, clinical, and GT results were collected. Results: 2,305 individuals met criteria and underwent GT between Jan. 2001and Dec. 2011. Of all tested subjects, 93% were female, median age was 55 yrs., 23% were of Ashkenazi Jewish (AJ) ancestry and 80% lived in an area with family income $50-100K/yr. BRCA1/2 mutations were present in 16%, 8% had unclassified variant (UCV), 76% had normal sequence. We excluded 460 individuals who had predictive GT for a familial mutation, and results are shown in the Table. For each carrier, an average of four additional relatives had GT. The most common criteria for GT was at least three cases of ovarian or breast cancer at any age on the same side of the family. BRCA mutations were most common among those AJ, Italian, Asian Oriental and English ancestry. Wait time for GT result improved from 107 wks. in 2001 to 8 wks. in 2011. Conclusions: In our tested population, the prevalenceof BRCA1/2 mutations was high. Over time wait times improved and more relatives were tested.
Mutation | N | % | ||
---|---|---|---|---|
BRCA1 | 100 | 6 | ||
BRCA2 | 74 | 4 | ||
UCV only | 171 | 9 | ||
Normal sequence | 1,500 | 81 | ||
Cancer history in carriers | BRCA1 N |
% | BRCA2 N |
% |
No cancer | 18 | 18 | 12 | 16 |
Breast cancer | 63 | 3 | 53 | 72 |
Ovarian cancer | 9 | 9 | 2 | 3 |
Breast and ovarian cancer | 5 | 5 | 3 | 4 |
Other cancer | 5 | 5 | 4 | 7 |
Median age breast cancer diagnosis | 42 | 44 | ||
Ancestry in carriers* | BRCA1 N |
% | BRCA2 N |
% |
Ashkenazi Jewish | 26 | 26 | 10 | 13 |
Italian | 16 | 16 | 8 | 11 |
Asian-oriental | 4 | 4 | 8 | 11 |
Eastern European | 5 | 5 | 5 | 7 |
Asian-other | 6 | 6 | 4 | 5 |
Abbreviations: BRCA, breast cancer; UCV, unclassified variant. *Same ancestry on paternal and maternal side.
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