Targeted therapy has transformed modern cancer treatment by attacking specific genes, proteins, or pathways that help cancer cells grow. Unlike traditional chemotherapy, which affects both healthy and cancerous cells, targeted therapy is more precise and often causes fewer side effects. However, this treatment is not suitable for everyone. Before prescribing targeted therapy, doctors perform a detailed evaluation to determine whether a patient’s cancer has the right characteristics to respond well. Understanding these factors can help patients and families make informed decisions about their treatment journey.
Detailed Molecular and Genetic Testing
One of the most important steps before prescribing targeted therapy is analyzing the genetic makeup of the tumor. This is done through molecular testing or genomic profiling. Doctors examine whether the cancer cells carry specific mutations or biomarkers that targeted drugs are designed to attack.
Some of the most common genetic mutations and markers include:
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EGFR mutations (seen in lung cancer)
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HER2 amplification (seen in breast and gastric cancer)
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BRAF mutations (common in melanoma)
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ALK and ROS1 rearrangements
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PD-L1 expression levels
If the tumor does not express these biomarkers, targeted therapy may not be effective.
This step ensures that treatment is personalized and tailored to the biology of each patient’s cancer. Without this testing, there is a risk of using medicines that may not provide any benefit.
Molecular testing also helps doctors understand how aggressive the cancer is and whether it might develop resistance to certain drugs. This information is crucial for choosing the right therapeutic approach.
Overall Health, Organ Function, and Medical History
Even if a patient is a good candidate at the molecular level, doctors must evaluate their overall health before prescribing targeted therapy. Some targeted drugs can affect the liver, kidneys, heart, or lungs, so doctors assess whether these organs are functioning well enough to tolerate the treatment.
They may check:
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Liver enzymes
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Kidney function tests
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Heart function (ECHO or ECG)
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Lung capacity
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Blood counts
Patients with pre-existing conditions such as heart disease, uncontrolled diabetes, or autoimmune disorders may require special monitoring or may not qualify for certain targeted drugs.
Doctors also review the patient’s current medications to avoid harmful interactions. For example, some targeted therapies can interfere with blood thinners, blood pressure medicines, or immune-modulating drugs.
Age is another consideration, though it is not usually a limiting factor. Instead, doctors focus on performance status—how well a patient can carry out daily activities.
Cancer Stage, Type, and Previous Treatment Response
The stage and type of cancer play a significant role in determining whether targeted therapy is appropriate. Targeted therapy is often recommended for cancers that are advanced, recurrent, or resistant to chemotherapy. However, in some early-stage cancers, it can also be used to improve outcomes when combined with surgery or radiation.
Doctors also consider how the patient responded to previous treatments:
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If chemotherapy was ineffective, targeted therapy may be the next step.
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If the cancer returned after treatment, molecular testing may reveal new mutations that can be targeted.
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If the tumor shrank with targeted drugs before, the same or an updated version may be used again.
In some cases, targeted therapy is given alongside immunotherapy or chemotherapy to enhance effectiveness. Doctors weigh all these factors to create the safest and most effective treatment plan.
Predicting potential resistance is another key area. Tumors can sometimes change or develop new mutations, making targeted drugs less effective over time. Doctors monitor these changes through repeat scans and blood tests.
Conclusion
Targeted therapy is a powerful and personalized approach to cancer treatment, but it requires careful evaluation before being prescribed. Doctors look closely at the tumor’s genetic profile, the patient’s overall health, organ function, cancer stage, and previous treatment response. This thorough assessment ensures that the therapy selected will offer the best possible outcomes with minimal side effects.
Dr AV Cancer Institute provides the best treatment regarding this, offering advanced genomic testing, expert oncologists, cutting-edge targeted therapies, and comprehensive patient care tailored to individual needs.
