[Oncogenetic consultation for breast cancer]

The Potential Contribution of BRCA Mutations to Early Onset and Familial Breast Cancer in Uzbekistan

Introuduction:

Breast cancer is the most common malignancy in women and affects approximately 1 out of 8 females in the US. Risk of developing breast cancer is strongly influenced by genetic factors. Germ-line mutations in BRCA1 and BRCA2 genes are associated with 5–10% of breast cancer incidence. To reduce the risk of developing cancer and to increase the likelihood of early detection, carriers of BRCA1 or BRCA2 mutations are offered surveillance programs and effective preventive medical interventions. Identification of founder mutations of BRCA1/2 in high risk communities can have a significant impact on the management of hereditary cancer at the level of the national healthcare systems, making genetic testing more affordable and cost-effective. BRCA1 and BRCA2 mutations in breast cancer patients have not been characterized in the Uzbek population. This pilot study aimed to investigate the contribution of BRCA1 and BRCA2 mutation to early onset and familial cases of breast cancer in Uzbekistan.

Methods:

A total of 67 patients with breast cancer and 103 age-matched disease free controls were included in this study. Utilizing SYBR Green based real-time allele-specific PCR, we have analyzed DNA samples of patients with breast cancer and disease free controls to identify the following BRCA1 and BRCA2 mutations: BRCA1 5382insC, BRCA1 4153delA, BRCA1 185delAG, BRCA1 300T>G, BRCA2 6174delT.

Results:

Three unrelated samples (4.5%) were found to be positive for the heterozygous 5382insCBRCA1 mutation, representing a possible founder mutation in the Uzbek population, supporting the need for larger studies examining the contribution of this mutation to breast cancer incidence in Uzbekistan. We did not find BRCA1 4153delA, BRCA1 185delAG, BRCA1 300T>G, and BRCA2 6174delT mutations.

Conclusion:

This preliminary evidence suggests a potential contribution of BRCA1 5382insC mutation to breast cancer development in Uzbek population. Taking into account a high disease penetrance in carriers of BRCA1 mutation, it seems reasonable to recommend inclusion of the 5382insC mutation test in future research on the development of screening programs for breast cancer prevention in Uzbekistan.

[Management of families at high risk for hereditary breast-ovarian cancers: the endocrinologist's point of view]

Most cancers have a sporadic physiopathology, but approximately 5 to 10% of breast cancers and 10% of ovarian cancers involve a genetic predisposition. Sometimes, the gene involved in these hereditary cancers can be identified (usually BRCA1 or 2), but most of the time it remains unknown. However, all women considered at high risk, because of their familial history, must be identified so they can be provided with the most adequate care, since the probability is very high that they develop such a cancer in the future. Fortunately, effective strategies have been developed to reduce this risk. Early detection of breast cancer is possible and prophylactic treatments (chemoprevention and prophylactic surgery) exist for both breast and ovarian cancers. Another reason why it is essential that these high risk women are identified is that treatment for hereditary cancers differs in some ways from that of sporadic cancers. It is best that counseling be given in an interdisciplinary cancer genetic clinic, where all practionners are aware of the latest data and guidelines.