Genetic Testing for Breast Cancer: Your Guide

If you’re in danger for breast most cancers, your physician might suggest genetic testing. Usually, genetic testing for breast most cancers refers to exams that look for gene mutations that increase an individual’s danger of creating this situation.

Doctors might recommend genetic testing for sure ladies who’ve breast most cancers or have danger elements that enhance the chance that they are going to develop breast most cancers sooner or later.

For ladies who’ve already been identified with breast most cancers, docs may additionally suggest exams to determine gene adjustments that affect how most cancers cells develop. This can be generally known as genetic testing, or it may be referred to as molecular profiling or next-generation testing. Knowing this data will help docs estimate your prognosis (outlook) and select remedies which are almost certainly to be efficient.

What Is Genetic Testing for Cancer?

Cancer is brought on by gene mutations (gene adjustments). Genes inform cells easy methods to make proteins, which play many roles within the cell. When genes are mutated, they trigger the cell to make irregular proteins that lead the cell to develop uncontrolled, resist loss of life, or accumulate harm.

Occasionally, most cancers is brought on by inherited gene mutations — adjustments which are handed down from father or mother to little one, and are current in all of an individual’s cells at start. More typically, most cancers is brought on by acquired gene mutations, which develop in a single cell throughout an individual’s lifetime.

Genetic testing normally appears for inherited gene mutations, and a few exams additionally look for acquired mutations. These exams “read” the DNA sequence inside cells to find out whether or not there are any adjustments inside genes that may trigger most cancers.

This sort of genetic testing is completely different from at-home DNA exams that present details about private traits and ancestry. The at-home exams can detect only some cancer-causing genetic mutations.

There are greater than 1,000 inherited gene adjustments that may trigger breast most cancers. Many individuals have high-risk gene adjustments that received’t be detected utilizing these exams. Additionally, these at-home exams aren’t normally lined by medical health insurance, whereas genetic testing by way of a physician could also be lined.

Types of Genetic Testing

Most sorts of genetic testing for breast most cancers assist ladies perceive whether or not they have inherited gene adjustments that may result in most cancers. In some circumstances, genetic exams can be utilized to assist decide what sort of breast most cancers a girl has.

BRCA Gene Testing

The most typical sort of genetic testing in individuals with breast most cancers contains exams that look for adjustments within the BRCA1 and BRCA2 genes. Mutations in these genes result in hereditary breast and ovarian cancer syndrome. People with BRCA gene mutations usually tend to develop breast and ovarian most cancers, in addition to different sorts of most cancers similar to pancreatic most cancers, prostate most cancers, and melanoma.

Who Needs BRCA Gene Testing?

Doctors might suggest BRCA gene testing for ladies with a private or household well being historical past that reveals they might be in danger. Those in danger embrace ladies who’ve been identified with:

• Breast most cancers earlier than turning 45 years previous, or with each breast and ovarian most cancers at any age
• Breast most cancers in each breasts, or twice in the identical breast
• Triple-negative breast most cancers earlier than the age of 60
• A private historical past of ovarian most cancers
• Breast most cancers and who’re of Ashkenazi Jewish descent

Those additionally in danger embrace:

• Men who’ve been identified with breast most cancers
• People who’ve developed a number of sorts of most cancers
• People who’ve a household historical past of breast most cancers, ovarian most cancers, fallopian tube most cancers, prostate most cancers, or pancreatic most cancers
• People who’ve shut relations who’re recognized to have a BRCA mutation

Doctors may additionally use completely different instruments to assist estimate an individual’s danger of breast most cancers. These instruments present if an individual is kind of prone to have a BRCA mutation and will help docs determine whether or not to suggest genetic testing.

How Is BRCA Gene Testing Performed?

BRCA gene testing begins with genetic counseling. The counselor will assist you to perceive the genetic testing course of.

They will ask about your private and household medical historical past. It might assist to carry any related medical data that you’ve for your self, in addition to details about which of your relations have had most cancers, the age they had been identified, and which sort of most cancers that they had.

During the genetic counseling assembly, you may as well ask the counselor questions on genetic testing, together with what the dangers and advantages are and what the potential outcomes might imply.

Usually, BRCA gene testing requires a blood pattern. A well being care supplier will draw blood out of your arm and ship it to a lab for testing. Occasionally, gene testing could also be carried out with a saliva check or from a cheek swab.

Once the exams are full, an individual present process testing could have one other assembly with the genetic counselor. The counselor will share the check outcomes and clarify what they imply.

What Does BRCA Gene Testing Tell You?

A constructive check outcome means that you’ve an inherited BRCA gene mutation that results in an elevated danger of creating most cancers. If you haven’t but developed most cancers, preventive remedies might assist decrease your danger.

Additionally, you might have to endure breast most cancers screening earlier and extra typically than ladies throughout the normal inhabitants. You may additionally be in danger for creating different sorts of most cancers. Your members of the family might need to be examined to see whether or not additionally they have this inherited mutation.

If you could have already been identified with breast most cancers, testing constructive for BRCA can present details about which most cancers remedies could also be simplest. BRCA-positive breast cancers may be handled with PARP inhibitor medicine, together with olaparib (Lynparza) and talazoparib (Talzenna).

A adverse check outcome signifies that genetic testing didn’t discover any inherited BRCA gene adjustments recognized to extend most cancers danger. This doesn’t assure that you simply received’t develop breast most cancers. It might imply that you’ve a mean danger of being identified with breast most cancers. It can be potential that you’ve an inherited mutation in a special gene apart from BRCA1 or BRCA2 that raises your danger of breast most cancers.

Sometimes, genetic testing outcomes say that you’ve a variant of unsure significance. This means that you’ve a BRCA1 or BRCA2 mutation, however specialists don’t but know whether or not this explicit gene change will increase breast most cancers danger. Talk to your genetic counselor to study extra about what this outcome might imply for you.

Genetic Testing for Other Inherited Gene Mutations

Some individuals inherit mutations that have an effect on different genes moreover the BRCA genes. Mutations that may increase most cancers danger embrace adjustments within the following genes:

• TP53
• PTEN
• PALB2
• ATM
• CHEK2
• BARD1
• NF1
• STK11

Many genetic exams look for mutations in these genes in addition to in BRCA genes. This sort of testing could also be referred to as multigene testing or expanded panel testing. These exams work equally to BRCA gene testing.

Human Epidermal Growth Factor Receptor 2 Testing

Human epidermal progress issue receptor 2 (HER2) testing will help docs diagnose breast most cancers’s molecular subtype. It will not be a genetic check. Doctors classify breast most cancers cells based mostly on which genes or proteins they include. Identifying the molecular subtype helps docs estimate outlook and know which remedies may fit finest.

When analyzing the molecular subtype, docs have a look at whether or not breast most cancers cells include the proteins HER2, estrogen receptor (ER), and progesterone receptor (PR). Some HER2 testing depends on genetic exams. ER and PR testing is achieved by way of different strategies.

The HER2 gene makes a protein, additionally referred to as HER2, that helps cells develop. Normal breast cells include low ranges of HER2. For about 1 out of 5 individuals with breast most cancers, the cancerous breast cells have adjustments within the HER2 gene.

The adjustments trigger the cell to make an excessive amount of HER2 protein, which makes the cells develop too quick. People with excessive ranges of HER2 of their breast most cancers cells are stated to have HER2-positive breast most cancers.

Who Needs HER2 Testing?

Generally, all ladies with invasive breast most cancers will endure HER2 exams. They will even be examined for ER and PR.

How Is HER2 Testing Performed?

During HER2 testing, docs take away a pattern of breast most cancers cells by way of varied procedures:

• Fine-needle aspiration biopsy — A tiny breast tissue pattern is eliminated with a skinny needle.
• Core needle biopsy — Breast tissue is eliminated with a barely bigger needle.
• Surgical biopsy — Doctors take out a breast lump throughout surgical procedure.

Once the breast tissue is eliminated, it’s despatched to a lab for testing. There are two methods to have a look at HER2 ranges. Immunohistochemistry measures ranges of the HER2 protein. Fluorescence in situ hybridization (abbreviated as FISH) is a check that measures ranges of the HER2 gene.

What Does HER2 Testing Tell You?

Whether breast most cancers is HER2-positive or -negative influences the remedies that an individual receives. If you could have HER2-positive most cancers, you might endure focused therapies that block the HER2 protein. These remedies received’t work for somebody with low ranges of HER2 of their most cancers cells. Drug choices embrace:

• Trastuzumab (Herceptin)
• Trastuzumab and hyaluronidase injection (Herceptin Hylecta)
• Pertuzumab (Perjeta)
• Trastuzumab/pertuzumab/hyaluronidase (Phesgo)
• Margetuximab (Margenza)
• Ado-trastuzumab emtansine (Kadcyla)
• Fam-trastuzumab deruxtecan (Enhertu)
• Neratinib (Nerlynx)
• Tucatinib (Tukysa)
• Lapatinib (Tykerb)

People present process remedy for HER2-positive most cancers might have to endure additional HER2 testing to seek out out whether or not remedies are working. If the remedy plan is profitable at killing the most cancers cells, testing might present low ranges of HER2. On the opposite hand, if a check reveals that there are excessive ranges of HER2 after remedy, it could imply that the remedy isn’t efficient or that most cancers has returned.

Treatments for HER2-positive breast most cancers typically work effectively. As a outcome, ladies with HER2-positive breast most cancers typically have a good prognosis in comparison with these with different molecular subtypes.

Talk With Others Who Understand

MyBCTeam is the social community for individuals with breast most cancers and their family members. On MyBCTeam, greater than 56,000 members come collectively to ask questions, give recommendation, and share their tales with others who perceive life with breast most cancers.

Has your physician advised genetic testing for breast most cancers? Share your experiences within the feedback beneath, or begin a dialog by posting in your Activities web page.