uncover the latest BRCA testing guidelines for identifying genetic cancer risks. Learn about the importance of genetic testing from healthcare experts on Meri Sehat

Genetic Testing For Breast Cancer

Humza Khizer

Overview

Breast cancer is one of the most prevalent forms of cancer affecting women worldwide, accounting for 1 in 8 cancer diagnoses globally<a href="#accordion">[1]</a>. While various factors contribute to the development of breast cancer, including lifestyle choices and environmental exposures; genetic mutations can significantly increase the risk of this disease. <a href="https://merisehat.pk/disease/breast-cancer">Inherited breast cancer</a>, often caused by specific genetic mutations, accounts for 5-10% of all breast cancer cases<a href="#accordion">[2]</a>. 
&nbsp;

Certain genes, such as BRCA1 and BRCA2, are known as tumor suppressor genes, which play a crucial role in repairing damaged DNA and preventing the growth of cancerous cells. However, specific mutations in these genes can impair their function, leading to an increased risk of breast and ovarian cancer. Approximately 1 in every 400 people carry a mutated BRCA gene<a href="#accordion">[3]</a>.

Besides BRCA1 and BRCA2, other gene mutations like TP53, PTEN, and PALB2 have also been associated with an elevated risk of breast cancer. 
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understanding the role of genetic testing for breast cancer

Genetic testing involves analyzing an individual&#39;s DNA to identify specific changes or mutations in genes that may be linked to an increased risk of certain diseases, including breast cancer. In the context of breast cancer, genetic testing primarily focuses on mutations in BRCA1 and BRCA2 genes. Inherited mutations in the BRCA1 and BRCA2 genes account for 3% of breast cancers and 10% of ovarian cancers<a href="#accordion">[5]</a>.

Genetic testing for breast cancer is typically recommended for individuals with a family history of breast or ovarian cancer, especially if multiple relatives have been affected or if there is a history of early-onset cancer. Moreover, individuals who are more susceptible to particular genetic mutations associated with breast cancer ( e.g. Ashkenazi Jewish ancestry), can gain significant advantages from undergoing genetic testing<a href="#accordion">[4]</a>. 
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As per the updated guidelines of the National Comprehensive Cancer Network (NCCN), genetic testing for breast cancer is recommended for individuals who meet specific criteria. Some of the criteria include<a href="#accordion">[6]</a>:

<ul>
	<li>A diagnosis of breast cancer before the age of 45.</li>
	<li>Being diagnosed with breast cancer between the ages of 45 and 60, along with having another personal diagnosis of breast cancer or having a close relative with breast, pancreatic, or prostate cancer, or an unknown family history.</li>
	<li>A diagnosis of triple-negative breast cancer before the age of 60.</li>
	<li>An invasive ovarian cancer diagnosis at any age.</li>
	<li>Male breast cancer diagnosis at any age.</li>
	<li>History of prostate cancer and one or more family member(s) with breast, ovarian, prostate cancer, or pancreatic cancer.</li>
	<li>History of pancreatic cancer and at least one close relative with ovarian or pancreatic cancer, or at least two close relatives with breast or prostate cancer.</li>
	<li>Family member with a known breast cancer mutation (e.g., BRCA).</li>
	<li>Having a personal diagnosis of breast cancer and having a close relative with breast cancer diagnosed before the age of 50 or ovarian cancer at any age, or at least two relatives with pancreatic or breast cancer, or a male relative with breast cancer, or Ashkenazi Jewish ancestry.</li>
	<li>Having a first or second-degree relative who meets any of the criteria. 
	&nbsp;</li>
</ul>

In addition to these criteria, the NCCN also considers other risk factors that warrant genetic evaluation. These guidelines primarily involve an individual&#39;s family history and personal history of breast or ovarian cancer, and sometimes, their personal history of other cancers. 
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After undergoing genetic testing for breast cancer, genetic counseling is essential to help individuals understand their test results and make informed decisions for themselves and their families. 
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<h5>Positive Test Result</h5>

<ul>
	<li>Indicates the presence of a mutation associated with hereditary breast and ovarian cancer.</li>
	<li>Allows individuals to take preventive measures to reduce the risk of developing cancer or detect it early if it occurs.</li>
	<li>Guides treatment decisions if the individual has already had breast or ovarian cancer.</li>
	<li>This implies a 50% chance for close family members (parents, children, siblings) to carry the same mutation. 
	&nbsp;</li>
</ul>

<h5>Negative Test Result (Already Had Cancer)</h5>

<ul>
	<li>Suggests the absence of a known mutation responsible for the individual&#39;s cancer.</li>
	<li>Further testing may be available for a more comprehensive analysis.</li>
	<li>Lowers the likelihood of an inherited mutation in the family, unless another relative has a known mutation.</li>
	<li>Genetic testing for unaffected family members may not be helpful unless a known mutation is present. 
	&nbsp;</li>
</ul>

<h5>Negative Test Result (Never Had Cancer)</h5>

If no known mutation is found in the family:

<ul>
	<li>The result is inconclusive as it may mean the person does not carry a known mutation but could still have an increased risk.</li>
	<li>Individual risk levels, appropriate screening, and preventive options vary based on the family history. 
	&nbsp;</li>
</ul>

If another family member has a known mutation and the individual tests negative:

<ul>
	<li>The person is not at higher risk for breast or ovarian cancer.</li>
	<li>The mutation cannot be passed on to offspring. 
	&nbsp;</li>
</ul>

<h5>Variant Of Uncertain Significance (VUS) Result</h5>

<ul>
	<li>Indicates a mutation in a gene linked to hereditary breast and ovarian cancer, but its effect on cancer risk is uncertain.</li>
	<li>Further testing may be required to clarify the mutation&#39;s significance.</li>
	<li>Individuals with VUS results are still considered at an increased risk for breast and ovarian cancer, and risk management varies based on individual and family factors. 
	&nbsp;</li>
</ul>

Note: Having a strong family health history of breast and ovarian cancer does not guarantee the presence of an inherited mutation. Also, many individuals at an increased risk for BRCA1 and BRCA2 mutations based on family history do not carry these mutations. Additionally, not all individuals with BRCA1 or BRCA2 mutations have a known family history of breast and ovarian cancer. 
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Receiving genetic testing results can be emotionally challenging, but it provides vital information for risk assessment and personalized management. If a harmful mutation is identified, individuals have options to consider, including increased surveillance, preventive measures, or even preventive surgeries, such as mastectomy or oophorectomy (removal of ovaries). 
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Conclusion

Genetic testing plays a vital role in assessing the risk of hereditary breast and ovarian cancer. Positive results enable individuals and their families to implement preventive measures and make informed decisions about their health. Negative results, depending on the context, may still indicate an increased risk. Genetic counseling is crucial in providing personalized guidance and support based on the test results and family history. 
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Key Points

<ul>
	<li>Breast cancer affects 1 in 8 cancer diagnoses globally, with genetic mutations contributing to increased risk.</li>
	<li>Inherited breast cancer accounts for 5-10% of cases, often linked to specific genetic mutations like BRCA1 and BRCA2.</li>
	<li>Genetic testing involves analyzing DNA to identify mutations associated with an increased risk of breast cancer.</li>
	<li>Genetic testing primarily focuses on BRCA1 and BRCA2 genes, accounting for 3% of breast cancers and 10% of ovarian cancers.</li>
	<li>Genetic testing is recommended for individuals with a family history of breast or ovarian cancer, early-onset cancer, or certain ethnic backgrounds.</li>
	<li>The National Comprehensive Cancer Network (NCCN) guidelines provide criteria for those who should undergo genetic testing.</li>
	<li>Positive test results indicate a mutation linked to hereditary breast and ovarian cancer, enabling preventive measures and treatment guidance.</li>
	<li>Negative test results may still carry an increased risk, depending on family history and personal factors.</li>
	<li>Variant of Uncertain Significance (VUS) results require further testing for clarification.</li>
	<li>Having a strong family health history of breast and ovarian cancer does not guarantee the presence of an inherited mutation.</li>
	<li>Genetic counseling is essential to help individuals understand test results and make informed decisions for themselves and their families. 
	&nbsp;</li>
</ul>