What is Targeted Therapy for Breast Cancer?

Targeted therapy is an important cornerstone of modern-day cancer treatment and part of the broader concept of precision medicine. Targeted therapy differs from traditional approaches in that it specifically targets molecules, genes, and cellular structures and mechanisms responsible for the uncontrolled proliferation of malignant cells. Targeted therapy is an alternative or option for patients with specific biomarkers or tumor characteristics. Let's explore what targeted therapy is, who can benefit from it, and what mechanisms can be targeted.

What is Targeted Therapy?

Many types of cancer cells can have mutated or abnormal molecules that promote their proliferation. Targeted therapy is based on drugs that target and inhibit these abnormal structures and processes specifically.

According to the NCI (National Cancer Institute), there are two main types of targeted therapy:

• Monoclonal antibody therapy: drugs produced in a laboratory that target specific cells or molecules.
• Small molecule drugs: drugs that penetrate cells to target specific molecules.

Since targeted therapy primarily focuses on biomarkers specific to a given tumor, biomarker testing is a critical step before considering it.

Testing typically includes assessing whether tumor cells are positive for hormone receptors or human epidermal growth factor receptor 2 (HER2), as well as analyzing specific genes and proteins. In addition, many other genetic tests can be used to determine if an individual has specific tumor biomarkers.

Who is eligible for targeted therapy in breast cancer treatment?

Targeted therapy is a type of accurate/precision medicine; thus, it is not suitable for all breast cancer patients. The NCI notes that targeted therapy can be used to treat HER2-positive breast cancer, hormone receptor-positive breast cancer, triple-negative breast cancer, and BRCA gene carriers. Therefore, patients with the following tumor characteristics can consider targeted therapy:

• HER2-positive breast cancer.
• Hormone receptor-positive breast cancer.
• Triple-negative breast cancer in specific circumstances.
• Carrying BRCA1orBRCA2gene variants.

The specific type of targeted therapy depends on the following factors:

• Cancer type and stage.
• History of previous treatment.
• The presence of certain biomarkers.
• Other cancer treatment responses.
• The existence of other health problems.
• Whether the cancer is recurring, advanced, or detected in the early stage.

Which targeted therapy drugs are used for HER2-positive breast cancer?

HER2 is medically introduced as a protein that stimulates the growth and proliferation of breast cells. But in some people, particularly women, the HER2 gene may be amplified or overexpressed in breast cancer cells, increasing the amount of this protein produced. As a result, cancer cells proliferate more rapidly than healthy cells. This genetic abnormality is referred to as HER2 positivity.

• Trastuzumab.
• Pertuzumab.
• The drug trastuzumab deruxtecan.
• Ado-trastuzumab emtansine.
• The drug tucatinib.
• The drug neratinib.
• The drug lapatinib.
• The medication Margetuximab.
• Margetuximab.

Some of these drugs are often combined with chemo and other cancer treatments. Recently, scientists have also been working on developing antibody-drug conjugates for HER2-positive breast cancer.

How do CDK4/6 and enzyme inhibitors treat hormone receptor-positive cancer?

Tumor cells with receptors for the female sex hormones progesterone and estrogen are indicative of hormone receptor-positive breast cancer. Targeted therapy is often combined with hormone therapy for this type of breast cancer. According to NCI, the following targeted drugs are effective in treating hormone receptor-positive breast cancer:

• CDK4/6 inhibitors: ribociclib, palbociclib, and abemaciclib.
• Alpelisib is a PI3K inhibitor.
• Capivasertib is an AKT inhibitor.
• Everolimus is an mTOR inhibitor.
• In certain cases, inavolisib is a PI3Kα inhibitor.
• Depending on certain circumstances, additional receptor-specific targeted medications.

CDK4 and CDK6 are enzymes that promote cell proliferation and are often defective in cancer cells. One class of targeted medications is CDK4/6 inhibitors, which block the action of these enzymes, thereby slowing cancer cell proliferation. NCI notes that “when added to endocrine therapy, CDK4/6 inhibitors improve progression-free survival in patients with estrogen receptor-positive, HER2-negative advanced breast cancer.”. Specifically, the use of ribociclib was associated with advantages for overall survival in individuals with metastatic breast cancer. Moreover, CDK4/6 inhibitors can also reduce the chance of recurrence of cancer in patients with early-stage, hormone receptor-positive, HER2-negative breast cancer.

What PARP inhibitors are available for BRCA-mutated breast cancer?

BRCA1 and BRCA2 are DNA repair genes that, when mutated, can significantly enhance the risk of developing breast cancer. For breast cancer patients with germline BRCA1 or BRCA2 variants, PARP inhibitors such as olaparib and talazoparib can be used to treat breast cancer.

How is targeted therapy used to treat triple-negative breast cancer?

As the name suggests, TNBC (triple-negative breast cancer) is identified or characterized by the lack of estrogen receptors, HER2 overexpression, and progesterone receptors. Therefore, hormone therapy and HER2-targeted therapy are generally ineffective in TNBC. However, recently, a monoclonal antibody called sacituzumab govitecan has been approved for the treatment of TNBC.

Can targeted therapy benefit patients with HER2-low breast cancer?

Targeted therapy was traditionally used to treat HER2-positive breast cancer. However, recent research has demonstrated that patients with HER2-low or HER2-ultra-low breast cancer can also benefit from targeted therapy. According to NCI, trastuzumab deruxtecan is an appropriate targeted therapy option for HER2-low or HER2-ultra-low breast cancer patients in certain clinical scenarios.

HER2-low breast cancer is an emerging concept, and it refers to breast cancer cells that have low levels of HER2 protein on their surface. Thus, this subgroup of breast cancer patients can benefit from HER2-targeted therapy.

When is targeted therapy started during cancer treatment?

In accordance with tumor biology and stage, targeted therapy can be applied:

• As neoadjuvant treatment/ before surgery.
• As adjuvant therapy after surgery.
• As a therapy for recurrent breast cancer.
• As a therapy for metastatic or stage IV breast cancer.

Targeted therapy can be employed in combination with other types of cancer therapy, which include chemotherapy, hormone therapy, surgery, and radiotherapy. Targeted therapy can be administered on its own as well.

What are the main benefits of targeted therapy over traditional cancer care?

The major advantage of targeted therapy is that it enables personalized treatment for cancer patients. The advantages of targeted therapy for breast cancer patients may include:

• Targeting specific cancer cell mechanisms.
• Treating breast cancer with specific biomarkers.
• Disease control in selected breast cancer patients.
• Combined use of targeted therapy with other cancer therapies.
• Treating previously untreatable genetic tumor abnormalities.

However, it is critical to note that targeted therapy is not necessarily safer or has fewer side effects than traditional cancer treatments. Each targeted drug has its indications, contraindications, and side effects.

What are the Side Effects of Targeted Therapy?

Despite targeting only cancer cell mechanisms, many targeted drugs can have several side effects because certain molecules are also present in normal cells.

The National Cancer Institute (NCI) reports that targeted therapy for breast cancer is frequently linked with:

• Diarrhea.
• Damage to the liver.
• Oral sores.
• Modifications to the nails and hair.

The specific adverse effects of targeted medications are determined by their target molecules and modes of action. As a result, some targeted medications may also have adverse effects that could be fatal and call for specialized supervision.

Why is biomarker testing essential before starting targeted therapy?

An essential component of any targeted therapy treatment plan is biomarker testing. The NCI emphasizes the importance of biomarker testing and the concept of “the right treatment for the right tumor.”. Therefore, before initiating targeted therapy, your doctor may recommend a series of tests to identify biomarkers to target. For example, the following tests may be used:

• HER2 gene/protein mutationHER2-targeted therapy.
• Hormone receptor positivity/Hormone receptor-targeted therapy..
• BRCA1/BRCA2 gene mutation PARP inhibitor therapy.
• PIK3CA/AKT/PTENgene mutationsTargeted therapy against these pathways.

The specific tests to be taken depend on the stage and type of cancer, as well as the intended targeted therapy.

How is targeted therapy shaping the future of breast cancer care?

Overall, targeted therapy has fundamentally changed the management of breast cancer patients. As an illustration, the discovery of HER2 as a protein that promotes cancer cell growth has enabled the development of a HER2-targeted therapy, greatly benefiting individuals with HER2-positive breast cancer. Furthermore, additional cellular processes have been discovered, and drugs have been developed to block other “drivers,” such as the PI3K, AKT, and CDK4/6 pathways. The NCI keeps publishing more research on targeted therapy and the issues related to breast cancer. Thus, targeted therapy is a continuously growing area of study.

Why choose Tender Palm Super-Speciality Hospital for Targeted Therapy for Breast Cancer in Lucknow, India?

Tender Palm Super-Speciality Hospital is one of the best hospitals for Targeted Therapy for Breast Cancer in Lucknow, India. Our experienced medical oncologists and breast cancer specialists use advanced targeted treatment protocols based on the specific biomarkers and characteristics of each patient's cancer. We provide personalized treatment planning, careful monitoring, and supportive care to help manage side effects and achieve better treatment outcomes. With comprehensive cancer care, modern treatment facilities, experienced specialists, and affordable treatment options, our Targeted Therapy cost is suitable for patients seeking high-quality Breast Cancer treatment in Lucknow, India.

To seek an Expert Consultation for Targeted Therapy for Breast Cancer in Lucknow, India:

Call us at +91-9076972161
Email at care@tenderpalm.com

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