Cancer treatment has dramatically changed over the past few years from one-size-fits-all approaches to highly personalized therapies. Precision oncology, a modern field that tailors cancer treatment based on the unique genetic profile of a patient’s tumor, stands at the forefront of this revolution. Precision oncology allows us to understand the molecular makeup of cancer and select treatments that target specific genetic mutations, thereby enhancing efficacy and minimizing side effects.
Central to precision oncology are molecular tests, which help identify genetic alterations and biomarkers in cancer cells. These tests guide oncologists in determining the best course of action, including targeted therapies, immunotherapies, or clinical trials.
In this blog, we’ll explore the concept of precision oncology, its role in cancer treatment, and the various molecular tests available to support this personalized approach.
What is precision oncology in cancer?
Precision oncology is a new and individualized type of cancer treatment targeting genetic and molecular characteristics unique to each patient’s type of cancer. It’s quite different from traditional cancer treatment where all patients receive the same form of treatment. Using state-of-the-art technology, advanced technologies can pick up the unique genetic mutations and biomarkers within cancer cells that allow doctors to personalize the treatment for each individual patient.
At the center of precision oncology is the understanding that no two cancers are alike. Even in patients with cancer of the same type, cancers can behave differently from one another because of genetic differences. Precision oncology enables doctors to pinpoint specific genetic alterations fueling the growth of tumor cells. Targeted therapy can be applied to inhibit such growths more effectively without causing many side effects, different from traditional treatments such as chemotherapy and radiation.
It has sometimes been referred to as the ‘treatment tailored’ strategy of personalized medicine. Tailored treatment means doctors would use treatments that have chosen depending on the unique molecular profile of the cancer. From this strategy, genetic testing combined with molecular profiling allow an oncologist to make precise drug, immunotherapy, and targeted therapy selection more likely to be most successful against a given patient’s type of cancer.
Precision oncology also allows for newer treatment options, including immunotherapy, which enhances the body’s immune system to recognize and attack cancer cells. It may also include clinical trials, where patients can receive the latest treatments before they are widely available.
In summary, precision oncology revolutionizes cancer treatment by offering highly personalized, effective, and less invasive treatment options, ultimately improving outcomes and reducing the impact of cancer therapies on a patient’s overall health.
What are the types of molecular tests available?
Molecular testing plays a critical role in precision oncology by identifying genetic mutations, alterations, and biomarkers specific to a patient’s cancer. These tests help guide treatment decisions by determining the most effective therapies tailored to the unique molecular profile of the tumor.
Here are the primary types of molecular tests used in cancer:-
1. Germline Testing
Germline testing searches for inherited mutations in a patient’s DNA that may increase the risk of developing certain cancers. It is usually done with a blood or saliva sample, and the focus is on changes in genes like BRCA1 and BRCA2, which are associated with breast, ovarian, and other cancers.
Purpose: Assesses hereditary cancer risk and whether genetic mutations are indeed passed from parent to child.
Example: Increased risk of breast and ovarian cancers by BRCA gene mutations.
2. Tumor Genomic Profiling: Somatic Testing
Tumor genomic profiling focuses on mutations within the DNA of the tumor itself rather than inherited mutations. It is a test that checks the genetic changes in the cancer cells and helps identify the mutations, gene fusions, amplifications, or deletions that drive the growth of cancer. Usually, it is done using a sample of the tumor obtained through biopsy or surgery.
Purpose: To detect specific mutations that can direct treatment decisions and predict a response to targeted therapies.
Example: Testing for mutations in genes like EGFR, ALK, or KRAS that can be treated with targeted therapies in lung or colon cancers.
3. Next-Generation Sequencing (NGS)
Next-generation sequencing is a broad molecular test that analyzes the genetic makeup of the tumor at a much deeper level than traditional methods. NGS can simultaneously examine hundreds of genes or even the entire exome, which is the part of the genome that encodes proteins, to identify mutations that could influence treatment choices.
Purpose: To provide a comprehensive perspective of genetic changes over thousands of genes, enabling detection of new therapeutic opportunities or clinical trials.
Example: Tumor genomic profiling of numerous cancers to identify actionable alterations
4. PCR Test Polymerase Chain Reaction Test
PCR testing amplifies particular segments of DNA to detect specific mutations or gene expressions. PCR tests can be used for tracking known mutations or monitoring the advancement and response to treatment. It is commonly applied in selective gene testing, such as EGFR mutations in lung cancer.
Purpose: detection of targeted genetic mutations, or monitoring minimal residual disease (MRD) of certain cancers.
Detect the BCR-ABL fusion gene in chronic myelogenous leukemia (CML).
5. Fluorescence In Situ Hybridization (FISH)
FISH testing employs fluorescent probes to detect specific genetic abnormalities, such as gene amplifications, deletions, or rearrangements in the cancer cells. It is commonly used for cancers like lymphoma, breast cancer, and bladder cancer to identify gene amplifications or translocations.
Purpose: To identify specific chromosomal changes that may help guide treatment decisions.
Example: HER2 amplification testing in breast cancer for eligibility for targeted treatment with trastuzumab.
6. Immunohistochemistry
Immunohistochemistry is a test of the presence of specific proteins or markers on the surface of cancer cells. It is used to find out what type of cancer someone has and whether they have specific proteins, for instance, HER2 in breast cancer or PD-L1 in lung cancer,.
Purpose: It helps evaluate the expression of the biomarkers that can aid in guiding the use of targeted therapies and immunotherapies.
Example: In breast cancer, HER2 overexpression; this is potential treatment using HER2 targeted drugs.
7. Liquid Biopsy
Liquid biopsy is a non-invasive test that analyses blood or other bodily fluids (like urine) to detect genetic mutations, tumor DNA, and other biomarkers associated with cancer. It’s mostly used for monitoring treatment response, detecting recurrence, or assessing minimal residual disease.
It is used to identify genetic alterations or mutations in a patient’s tumor without needing a tissue biopsy.
Example: Detection of circulating tumor DNA (ctDNA) in blood samples to identify mutations in cancers such as lung or colorectal cancer.
8. Circulating Tumor Cell (CTC) Testing
CTC testing detects cancer cells that have broken off from the primary tumor and can circulate in the bloodstream to other parts of the body. It is usually applied to metastatic cancers to monitor the progression of the disease and the response to treatment.
Purpose: To monitor metastasis and the effectiveness of treatment.
Example: In breast cancer, CTC monitoring to determine how well a patient is responding to treatment.
Molecular testing in cancer has transformed the way doctors understand and treat the disease. These tests identify specific genetic mutations and alterations in cancer cells, thus tailoring treatment strategies to target the unique aspects of each tumor. Utilizing a combination of genetic tests, tumor profiling, and advanced technologies such as NGS and liquid biopsies, oncologists can offer more precise, effective treatments, thus improving outcomes and quality of life for cancer patients.
Dr. Pooja Babbar: A Decade of Expertise and Success Stories
With more than a decade of experience in medical oncology, Dr. Pooja Babbar has been a guiding light for many patients fighting against cancer. Her deep expertise, compassionate approach, and commitment to the latest advancements in cancer treatment have made a difference in the lives of the patients she has treated.
Dr. Babbar’s success stories reflect her commitment to personalized care through precision medicine and innovative therapies for the best possible outcome. Whether it is chemotherapy, immunotherapy, or precision oncology, the comprehensive care of Dr. Babbar continues to bring hope and healing to cancer patients.
Whether it is you or a dear one seeking expert guidance to navigate the journey of your cancer, Dr. Pooja Babbar stands as a trusted specialist where you can expect exceptional care and successful results.
