W 16: An Investigation Into the Distribution of BRCA 1/2 Mutation/Ness Breast and Ovarian Cancer Populations
Associate Global Feasibility Lead
Quintiles United Kingdom
The objective of this study is to identify the patient distribution of BRCA1/2 mutation specific Ovarian and Breast cancer populations that could potentially benefit from targeted therapies, such as poly (ADP-ribose) polymerase (PARP) inhibitors.
For this study, we reviewed literature and databases from existing investigations that include BRCA1/2 ovarian and breast cancer mutation prevalence, comparing the methods and results to build an overall picture of BRCAmut distribution.
Quantitative data included incidence rate and prevalence for breast cancer and ovarian cancer by country (GLOBOCAN).
BRCA 1/2 mutations are shown to range from 5–15% in ovarian cancers and 20–25% in hereditary breast cancers (NIH. 2015, Ramsus S.J et al. 2009). BRCAness or homologous recombination repair deficiency (HRD) tumors show a large degree of complexity as the HRD phenotype can be present in many ovarian breast cancer tumor types; up to 50–60% of women with epithelial ovarian cancer have BRCAness phenotype (Edmondson R.J. 2011).
Literature indicates that there are ethnic groups more predisposed to the BRCA 1/2 mutation than others;
‘…the frequency varies, geographically and between different ethnic groups.’ (Ramsus S.J et al. 2009). Observing different ethnic/ racial population show that these mutations are more common in Ashkenazi Jewish, Norwegian, Dutch, Icelandic, African Americans, Hispanics, Asian Americans and Non- Hispanics white population (NIH. 2015).
Data base – WHO GLOBOCAN 2015
-Region level OC and BC patient distribution (Incidence/ Prevalence)
- North America (BC: 91.6, 671236; OC: 8.1, 41587)
- CEE (OC:1.4, 48950; BC: 47.7, 304311)
- Australia/ New Zealand (OC: 7.6, 2954; BC: 85.8, 43931)
- Western Europe (OC: 7.5, 15987; BC: 91.1, 399841)
- Latin America (OC: 536, 32328; BC: 47.2, 354772)
- Africa (OC: 4.8, 27706; BC: 36.2, 291061)
- The proportion of patients with breast cancer or ovarian cancer that have the BRCA 1/2 mutation can vary, as shown by reviewing literature.
- Regional distribution between breast and ovarian cancer patients differs greatly with OC having the highest incidence and prevalence within Western Europe compared with breast cancer which has the lowest. As BRCA 1/2 mutation are hereditary this may suggest that there may not be a strong link between the occurrence of breast and/ or ovarian cancer stemming from BRCA 1/2 mutations.
- An increased awareness of the distribution of breast and ovarian cancer patients with the BRCA 1/2 mutation could help future feasibility studies and clinical strategies, to better target effective countries and/ regional areas.
- This investigation has identified the key ethnic groups that predominantly have this mutation.
- Breast cancer screening practices may have an effect on the ranges indicated within this investigation – as some countries class women at high-risk of breast cancer through family history or regular screening with the use of mammograms/ MRI.
- The robustness of the findings were bolstered by combining a range of data sources and types with the additional data from GLOBOCAN, the review of previous investigations into BRCA 1/2 populations and calculation of new patient populations within regional areas.