Change in the penetrance of founder <i>BRCA1/2</i> mutations? A retrospective cohort study
Bibliographic record
Abstract
There has been much discussion regarding the penetrance of breast cancer in BRCA1 / 2 mutation carriers (hereafter “carriers”). Both genetic and epigenetic factors could be influencing the reported penetrance estimates. We wanted to establish whether the penetrance of BRCA1 / 2 mutations is changing over time. To limit the genetic variability, we studied a cohort of 292 Ashkenazi Jewish (AJ) women diagnosed with first primary invasive breast cancer between 1 January 1980 and 1 November 1995 at a single Montreal Hospital, without regard to family history. All women were diagnosed at less than 65 years of age. Pathology blocks were identified from all women and the three AJ founder mutations in BRCA1 / 2 (185delAG, 5382insC ( BRCA1 ) and 6174delT ( BRCA2 )) were identified in archival samples using PCR based techniques described previously.1 We identified 41 (14%, 95% CI 10.2-18.6) BRCA1/2 carriers (31 in BRCA1 and 10 in BRCA2 ). The difference in mutation frequency between BRCA1 and BRCA2 carriers (10.6% v 3.4%) is statistically significant (Z=3.40, p=0.0007). Given that the population allele frequencies of AJ founder mutations in BRCA1 and BRCA2 are approximately equal (∼1%), this would suggest that BRCA1 has a higher penetrance than BRCA2 by age 65. This observation supports previous data from Canada.2 We then divided the data into quartiles by year of diagnosis and determined whether the proportion of mutation carriers was changing over time. The number of founder BRCA1 / 2 mutations per quartile of year of diagnosis increased from eight (11.0%) to 15 (20.5%) over the 15 year period of the study, and the χ2 p value for the trend in mean scores was 0.047 (table 1). This suggests that the penetrance of BRCA1 / 2 mutations to the age of 65 years is increasing. This is important, as previous studies of …
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".