BRCA Testing and Breast Cancer Prevention: A Public Health Imperative

BRCA Testing and Breast Cancer Prevention: A Public Health Imperative

Sub: Sci

Sec: Health

Why in News

October is recognized as Breast Cancer Awareness Month, bringing attention to the importance of BRCA testing for identifying hereditary breast and ovarian cancer risks. The case of Angelina Jolie and her preventive surgeries has spotlighted the potential of genetic testing to prevent cancer, highlighting the need for widespread access and awareness.

What is Breast Cancer?

Breast cancer is a disease in which cells in the breast grow out of control. There are different kinds of breast cancer. The kind of breast cancer depends on which cells in the breast turn into cancer.

Breast cancer can spread outside the breast through blood vessels and lymph vessels. When breast cancer spreads to other parts of the body, it is said to have metastasized.

The common kinds of breast cancer are—

Invasive ductal carcinoma: The cancer cells begin in the ducts and then grow outside the ducts into other parts of the breast tissue. Invasive cancer cells can also spread, or metastasize, to other parts of the body.

Invasive lobular carcinoma: Cancer cells begin in the lobules and then spread from the lobules to the breast tissues that are close by. These invasive cancer cells can also spread to other parts of the body.

Causes of Breast cancer

Breast cancer is not a transmissible or infectious disease. Unlike some cancers that have infection-related causes, such as human papillomavirus (HPV) infection and cervical cancer, there are no known viral or bacterial infections linked to the development of breast cancer.

Certain factors increase the risk of breast cancer including increasing age, obesity, harmful use of alcohol, family history of breast cancer, history of radiation exposure, reproductive history (such as age that menstrual periods began and age at first pregnancy), tobacco use and postmenopausal hormone therapy.

Understanding Hereditary Breast and Ovarian Cancer (HBOC)

Hereditary Cancer: Occurs when an individual inherits mutations in cancer-causing genes. BRCA1 and BRCA2 mutations are the most well-studied, causing Hereditary Breast and Ovarian Cancer (HBOC).

The BRCA gene (BRCA stands for BReast CAncer gene) refers to two genes, BRCA1 and BRCA2, which play a crucial role in suppressing tumors by repairing DNA damage. Mutations in these genes can impair their ability to repair DNA, leading to an increased risk of several cancers, particularly breast and ovarian cancers.

Germline Mutations: These mutations predispose individuals to multiple cancers, including breast, ovarian, prostate, pancreatic, and gastric cancers.

Women with BRCA mutations face a 69-72% risk of breast cancer and a 17-44% risk of ovarian cancer by age 80. This is significantly higher compared to the general population’s lifetime risks of 12% for breast cancer and 1% for ovarian cancer.

Preventive Measures: Options like prophylactic mastectomy and oophorectomy can reduce the risk of developing cancer by 90-100% and significantly lower cancer-related deaths.

The Need for Population-Based Testing in India

Advances in next-generation DNA sequencing and genomics make large-scale population testing possible. However, India faces challenges in implementing this model due to the high costs of testing.

Next-Generation Sequencing (NGS): It is a modern DNA sequencing technology that has revolutionized genomic research by allowing the sequencing of DNA and RNA much more quickly and cheaply than the previously used Sanger sequencing.

The concept of a liquid biopsy is a revolutionary technique that offers a less invasive alternative to surgery.

Advantages of NGS:

Speed: Enables rapid sequencing of large amounts of DNA/RNA.

Cost-Effective: Lower cost per base compared to traditional sequencing methods.

Comprehensive: Can detect a wide range of genetic variations, including SNPs, insertions, deletions, and structural variations.

Scalability: Can be scaled to fit a variety of experimental needs, from small targeted studies to large genome-wide analyses.