Through linking test results to electronic health records in England from 1995 to 2019, researchers estimated risks of a second primary cancer after breast cancer for BRCA1/2 carriers (Table 1) as well as risks over 10 years (Table 2). This study gives us more generalizable information about cancer risks to help guide risk assessment and management.
Table 1: Second Primary Cancer Risks in BRCA1 and BRCA2 Carriers
| Second Primary Cancer Type | BRCA1 | BRCA2 | ||
| SIR | HR | SIR | HR | |
| Contralateral breast | 15.6 | 3.6 | 7.7 | 2.4 |
| Ovarian | 44 | 33 | 16.8 | 12 |
| Combined non-breast or ovarian | 2.18 | 1.45 | 1.68 | |
| Colorectal | 4.8 | 2.93 | ||
| Endometrial | 2.92 | |||
| Pancreatic | 5.72 | 3.56 | ||
| Male breast | 13.1 | |||
| Prostate | 5.61 | |||
SIR: Standardized Incidence Ratio (represents comparison with population-level incidences); HR: Hazard Ratio (represents comparison with non-carriers); A blank cell represents insignificant data.
Table 2: Cancer Risks Over 10 Years
| Cancer Type | BRCA1 | BRCA2 | Non-Carriers |
| Contralateral breast | 16.0% | 12.0% | 3.6% |
| Ovarian | 6.3% | 3.0% | 0.4% |
| Combined non-breast or ovarian | 7.8% | 6.2% | 4.9% |
Allen, et al. J Clin Oncol. 2025;43(6):651-661. PMID: 39475295. Article available at: https://ascopubs.org/doi/10.1200/JCO.24.01146. Social media post available at: https://tinyurl.com/post1282025.