Global Disparities in Breast Cancer Genetics Testing, Counselling and Management.

Area of Science:

• Oncology
• Genetics
• Preventive Medicine

Background:

• Hereditary breast cancer, primarily linked to BRCA1 and BRCA2 mutations, constitutes 5-10% of all breast cancers.
• Genetic testing is recommended when there's a 10% probability of detecting a mutation, assessed by models like BOADICEA and Manchester Scoring System.
• Risk-reducing strategies, including bilateral mastectomy, can decrease breast cancer risk by 90-95% in unaffected BRCA mutation carriers.

Purpose of the Study:

• To review current strategies for managing hereditary breast cancer risk.
• To highlight advancements in genetic testing and targeted therapies.
• To address disparities in access to breast cancer genetics services, particularly in low-resource settings.

Main Methods:

• Review of risk assessment models (BOADICEA, Manchester Scoring System) for genetic testing.
• Evaluation of risk-reducing interventions: prophylactic mastectomy, surveillance (mammography, MRI), and chemoprevention.
• Discussion of novel genetic testing technologies (next-generation sequencing, multigene panels) and targeted therapies (PARP inhibitors).

Main Results:

• Bilateral risk-reducing mastectomy significantly lowers breast cancer risk in BRCA carriers.
• Risk-reducing contralateral mastectomy is advised for BRCA-associated breast cancer patients due to a 40% contralateral risk.
• Advancements in genetic testing have reduced cost and time, enabling treatment-focused testing and targeted therapies like PARP inhibitors.

Conclusions:

• Multidisciplinary clinics effectively manage hereditary breast cancer risk, but are limited to high-income settings.
• Prohibitive costs and lack of genetic counselors hinder breast cancer genetics services in low- and middle-income countries.
• Improving access to quality treatment and addressing the stigma associated with family history are crucial for low-resource settings.