What is Molecularly Targeted Therapy for Cancer? An Overview

Molecular Targeted Therapy for Cancer

Molecular targeted therapy is a kind of cancer treatment that makes use of the interaction between drugs or other chemicals and the molecular pathway, proteins or genes of cancerous cells to destroy them with little or no destruction of normal cells.

What Is Molecular Targeted Therapy?

It entails the utilization of agents, which disrupt particular molecules (normally proteins), which are implicated in:

• Cell enlargement in cancer cells
• Progression
• Survival
• Metastasis

Targeted therapy contrasts with the traditional chemotherapies that destroy all cells that grow fast; this therapy is intended to interfere with certain abnormalities that cancer cells have in their cells rather than the normal cells.

Targeted Therapy in Cancer Treatment

A relatively new and growing treatment trend in cancer is targeted therapy, where drugs or other substances target specific molecules that have a role in the growth, survival and spread of the cancerous cells: a more accurate, somewhat less toxic, alternative to classical chemotherapy.

What Is Targeted Therapy?

Targeted therapy:

• Targets certain molecular levels (e.g., proteins, genes) that are linked with cancer.
• Spares majority of normal cells unlike chemotherapy that targets all the quickly changing cells.
• But might be applied as single therapy or in combination with chemotherapy, radiation, or immunotherapy.

Types of Targeted Therapy for Cancer

Targeted cancer therapies may be grouped in accordance with the way they work upon the cancerous cells or the particular molecular people they influence. The synopsis of the key kinds of targeted therapies is given as follows:

Cancer Targeted Therapy Categories

Monoclonal Antibodies (mAbs)

• These are artificial antibodies, which bind themselves to certain proteins on the surface of the cancerous cells.

Mechanisms:

• Signals that trigger block growth (e.g., HER2)
• Bring toxins or radiation to the cancer cells directly
• Cause the attack by immune factors cancer cells

Small Molecule Inhibitors

• They are the medications that get into cells and inhibit some enzymes or proteins which are used in the multiplication of cancer cells.

Mechanisms:

• Tyrosine kinase inhibitor or serine/threonine kinase inhibition
• To interfere with signaling pathways within cancer cells

Angiogenesis Inhibitors

• The newer ones inhibit the development of new blood vessels (angiogenesis) required by tumors to expand.
• Target: VEGF/VEGFR pathway

Hormone-Targeted Therapies

• Applied in conditions where the treatment involves the hormone-dependent cancers such as estrogen or androgen-based.
• Targets: Estrogen receptor (ER), Androgen receptor (AR)

CDK Inhibitors

• Attack cyclin-dependent kinases, which are proteins that control the cell cycle.

PARP Inhibitors

• Target flaws in DNA repair (synthetic lethality) especially some BRCA mutant cancers.

Proteasome Inhibitors

• Inhibition of the block breakdown of proteins in cells, which cause death of cancer cells.

Epigenetic Modulators

• Change the expression of genes without any changes to the DNA sequence, and may do so by influencing some aspect of histone acetylation or DNA methylation.

Tumor-Agnostic Therapies

• Attack individual mutations in the cancer without depending on their origin.

How does targeted therapy work in cancer?

The concept of targeted therapy in cancer is that it disrupts actions of particular molecules which aid the growth dividing, survival, or spread of cancerous cells. This contrasts with traditional chemotherapy, which harms normal as well as cancerous rapidly-dividing cells, targeted therapy tends to minimize damage to normal tissue, by targeting unique properties of cancer cells.

Mechanisms by which Targeted Therapy works

These are the key mechanisms of targeted therapy applied to destroy cancer cells:

Inhibition of Signal Transduction (Signal Blocking)

• Abnormal signaling pathways are frequently used by cancer cells to develop and to reproduce.
• Targeted therapy drugs include inhibitory receptors, such as EGFR, or HER2 on the surface of cancerous cells.
• This prevents the messages of growth to reach the nucleus of the cell.

Causing Apopheresis in Cancer Cells

• There are therapies that trigger natural “suicide” programs within the cell known as apoptosis.
• Proteins that are overexpressed in cancer cells in order to evade death.

Anti-Angiogenesis Stopping Tumor Blood Supply

• In order to grow, tumors require new blood vessels (angiogenesis).
• Targeted medications inhibit such signals as VEGF and deprive the tumor of oxygen and nutrients.

Cell Cycle Blockade

• There is uncontrolled division of cancerous cells. Spot chemicals have the ability to inhibit check points in the cycle of cell division.

Disturbance of DNA Repair (Synthetic Lethality)

• Mutation on some cancer cells ( e.g. BRCA1/2 ) makes their DNA repair system a weak tool.
• DNA repair By interfering with backup repair systems, the death of cells is caused by drugs such as PARP inhibitors.

Transportation of Toxins to Cancer Cells

• Other monoclonal antibodies directly take chemotherapy or radioactive material to the cancer cells themselves.

Dropping Toxins to Cancer Cells

• Other monoclonal antibodies take chemotherapy or radioactive materials directly to cancerous cells.

Benefits of Molecular Targeted Therapy

Molecular targeted therapy has a number of important advantages over conventional treatments for cancer, particularly chemotherapy and radiation. They are meant to target specific molecular alterations in cancer cells, so treatment is more specific and possibly more effective.

Key Benefits of Molecular Targeted Therapy:

• Precision in Targeting Cancer Cells
• Fewer and Milder Side Effects
• Oral Availability
• Improved Effectiveness in Specific Cancers
• Can Work When Chemotherapy Fails
• Enables Personalized Medicine
• Tumor-Agnostic Use
• Can Be Combined with Other Therapies
• Monitorable with Biomarkers
• Wider Availability & Accessibility

Targeted Therapy vs Chemotherapy

Targeted Therapy

• In targeted therapy the medication disrupts the action of a particular molecular target, including protein, gene, or receptor that is implicated in cancer cell growth and survival. 
• It is created on the basis of thorough molecular study of the tumor, and will only work when the target exists.  
• Targeted therapy is very precise and usually based on the genetics of the tumor of the person. 
• Molecular testing (e.g. to state EGFR, BRAF, ALK mutations) is a common test performed by doctors to check the eligibility of a patient to a specific targeted drug. 
• Targeted therapies primarily attack cancer cells and their specific mutations, and tend to cause less, and milder, side effects. 
• The usual side effects could be rash on the skin, weariness, or minimal elevation of the liver. 
• Most targeted drugs, particularly small molecule inhibitors come in an oral form, thus making their long-term administration more convenient. 
• The others are intravenous yet applied in more specific and continuous form. 
• In the cancers whose molecular abnormalities can be identified, targeted therapies can be quite effective. 
• Under targeted therapy, the tumors might develop new mutation and make the drug inefficient (e.g. T790M EGFR mutation lung cancer).

Chemotherapy

• Chemotherapy is effective because of its random nature of killing all the fast dividing cells within the body. 
• Not only cancer cells are affected but also the healthy cells such as the bone marrow cells, gastrointestinal tract and even the follicle hair cells. 
• However, chemotherapy is mostly non-selective, and it is chosen according to the type and stage of the cancer and not based on the specific genetic signatures. 
• The majority of chemotherapy schemes are unified and applied commonly amongst patients with comparable cancerous entities irrespective of their molecular appearance. 
• The chemotherapy sessions impose numerous effects on the normal cells, and the side effects of it are more systematic in nature (i.e., loss of hair, nausea, vomiting, loss of energy, diarrhea and suppressed immunity as a result of the bone marrow suppression). 
• Chemotherapy may be given intravenously or by injection, frequently in courses (e.g. every 3 weeks), with some rest periods to enable the body to regain its normal functions after the effects of the toxics have taken place. 
• Less specific but often very effective is chemotherapy, which can be first-line treatment in very fast-growing cancer, or in diseases whose molecular target is unknown. 
• It is still vital in treatment of numerous malignancies such as breast, colon cancer as well as ovarian cancer especially at early stages. 
• Drug efflux pumps and increased DNA repair can also develop resistance in chemotherapy. 
• Chemotherapy is available almost everywhere and does not involve genetic testing in advance, even though it is usually more toxic.

Targeted Therapy Side Effects Cancer

Traditional cancer chemotherapy is normally accompanied by many and general side effects but targeted therapy has fewer and more special side effects since it concerns itself with molecular characteristics peculiar to cancerous cells. It may possibly create several minimal to severe side effects though in the type of drug, target, and reaction of an individual.

Below is a summary of some of the more frequent and more severe side effects of targeted cancer treatments:

Typical Side effects of a Targeted Therapy:

Skin Problems

• Rashes (particularly the eruptions resembling acne (which is most frequent after EGFR-inhibitor use, such as erlotinib, cetuximab))
• Itchy, drying, red skin
• Hand-foot syndrome (palmar-plantar erythrodysesthesia): redness, pains and peeling of soles and palms

Changes of Hair and Nails

• Change of hair texture(from curly hair to straight, or vice versa) Hair thinning
• Crackler nail, paronychia (infectious painful fingernails)

Gastrointestinal Symptoms

• Diarrhea, usually more common in case of EGFR or HER2 inhibitors
• Nausea, vomiting
• Mouth ulcers (mucositis)

Fatigue

• A common side effect experienced with VEGF or mTOR inhibitors in particular, but many medications have the same effect

Factors affecting cost of targeted therapy in cancer

The price of targeted cancer therapy can be extremely variable based on a host of important medical, logistical, and economic considerations. Targeted therapies tend to be costly because they are so specific and precise, but the ultimate expense to the patient is based on a variety of variables.

Major Factors Affecting the Cost of Targeted Cancer Therapy:

• Type of Drug and Targeted Molecule
• Cancer Type and Stage
• Molecular Testing Requirements
• Healthcare Setting and Location
• Duration and Dosage of Treatment
• Drug Availability and Import Status
• Supportive Medications and Monitoring
• Doctor’s Expertise and Treatment Center

Targeted therapy breast cancer

A special treatment against breast cancer is the targeted therapy that acts on specific molecules or pathways related to the development of cancer cells. It is chiefly applied to HER2-positive, hormone receptor-positive, and cancer with BRCA mutation of the breast.

When Targeted Therapy in Breast Cancer Is Used?

It uses targeted therapy depending on the results of biomarker testing, which determines:

• HER2 status is the state (Human Epidermal Growth Factor Receptor 2)
• Hormone receptor (HR) - negative (no estrogen receptors and/or progesterone receptors).
• Mutations of the BRCA genes
• Mutation in PIK3CA (in HR + / HER2 - cancer)
• PD-L1 expression (in the breast cancer that is triple-negative)

Targeted therapy for lung cancer

The targeted lung cancer therapy is among the revolutionizing steps in the field of oncology, and in non-small cell lung cancer (NSCLC). What it does is that it will inhibit certain genetic mutation or proteins that promote the growth and survival of cancer cells.

Who is Eligible for Targeted Therapy in Lung Cancer?

Targeted therapy is preferentially applied in non-small cell lung cancer (NSCLC) (primarily of adenocarcinoma type) in cases of a specific gene mutation or rearrangement of the tumor. These include:

• EGFR mutations
• ALK rearrangements
• ROS1 fusions
• BRAF V600E mutation
• MET exon 14 skip
• RET rearrangements
• NTRK fusions
• KRAS G12C mutation

Before initiating targeted therapy, it is important to test biomarkers (PCR, NGS, FISH, or IHC).

Why Choose GetWellGo for Molecular Targeted Therapy?

GetWellGo is regarded as a leading supplier of healthcare services. We help our foreign clients choose the best treatment locations that suit their needs both financially and medically.

We offer:

• Complete transparency
• Fair costs.
• 24 hour availability.
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• Online consultation from recognized Indian experts.
• Assistance in selecting India's top hospitals for molecular targeted therapy.
• Expert doctor with a strong track record of success
• Assistance during and after the course of treatment.
• Language Support
• Travel and Accommodation Services
• Case manager assigned to every patient to provide seamless support in and out of the hospital like appointment booking
• Local SIM Cards
• Currency Exchange
• Arranging Patient’s local food