It is important to remember that breast cancer is not necessarily going to act the same in everyone, even if there are cancerous tumors that are forming in the same location. The biological factors such as receptors and genes within the tumor could play a role in determining how fast the cancer spreads and reacts to treatment options. However, the precision medicine approach looks at what the tumor is made up of to aid in the decision process for treatment.
What Is Precision Medicine?
Precision medicine refers to the technique of treating a patient using specific details about their illness in order to find the best form of therapy for the patient. For instance, in breast cancer, this may include looking at the hormone receptors, HER2, genetic mutations, among others. The aim is not only to detect the presence of cancer but to determine the biology of the disease. This will help in determining the most beneficial treatment for an individual.
Why Is Precision Medicine Important in Breast Cancer?
Breast cancer is a biologically heterogeneous disease. There can be patients suffering from tumors of equal sizes, but their disease can differ considerably and require separate treatment regimens. With personalized assessment, healthcare providers can:
- Find out what kind of treatment targets need to be addressed.
- Choose the right systemic treatment.
- Calculate the chances of the treatment’s success.
- Understand which patients can benefit from certain clinical trials.
- Exclude ineffective therapy options.
Such an assessment enables healthcare providers to give more individualized treatment to their patients.
What Biomarkers Are Used in Breast Cancer?
Biomarker refers to biological markers which give us data on cancer cells. The most common breast cancer biomarkers are estrogen receptors (ER), progesterone receptors (PR) and HER2. ER/PR tests are used for determination of contribution of hormonal signaling in tumor formation. HER2 test is done for detection of elevated activity of HER2 protein or gene. Other markers can also be studied in case if it can influence treatment decision.
What Are the Molecular Subtypes of Breast Cancer?
There is a broad classification of breast cancer based on the types of receptors and markers present in the tumor cells. In hormone receptor positive tumors, there are either estrogen receptors or progesterone receptors or both, while in HER2 positive cancers, there is more HER2 activity. There may also be genetic changes in some cases of hormone receptor positive and HER2 negative tumors like PIK3CA mutation. However, identifying these characteristics will help in determining a particular treatment for selected patients.
What Is the Role of Genetic Testing?
The genetic test for breast cancer may look at either an inherited genetic mutation or a mutation that only occurs in cancerous tissue. The following two kinds of genetic tests can be performed:
- Inherited genetic test: Looks at the DNA from either blood or saliva samples to find out whether any gene mutations have been inherited from one’s parents. The presence of certain mutations may increase the chances of breast cancer.
- Cancer genetic test: Looks at the DNA from cancer tissue to determine what kind of mutation there might be.
This knowledge can help a physician evaluate the patient’s risk of cancer as well as some other features of the tumor.
How Does Precision Medicine Guide Treatment?
After identifying appropriate biomarkers, the findings can be used to determine the best treatment approach. For instance, endocrine therapy can be recommended for the hormone-receptor positive disease while HER2 positive cancers can be treated with HER2-targeting drugs. Patients having specific molecular changes can receive targeted therapy that inhibits these pathways. Precision medicine can impact the selection of chemotherapy, immunotherapy, clinical trials, and drug combination therapies. However, it is imperative to note that Alpelisib, Palbociclib, and Fulvestrant are critical medications that play a key role in the personalized treatment of some types of breast cancer.
What Are the Benefits of Precision Medicine?
Some of the potential benefits of personalized treatment include:
- Informed selection of treatment modality
- Identification of molecular targets
- Increased knowledge about tumor biology
- Ability to explore options for targeted treatment modalities
- Better selection of patients for some clinical trials
- Avoidance of ineffective treatments
However, there is no certainty that personalized medicine will be successful. There are cases when cancer develops resistance even after being responsive to treatment.
What Are the Challenges and Future of Precision Medicine?
Precision medicine still has some barriers, such as:
- Treatment is not available for every mutation.
- Some mutations can be difficult to understand.
- Tests might need additional financial support.
- There may be technical restrictions in tests.
- A delay in obtaining the results of tests may take place.
As science advances, new technologies will be developed to improve the results of molecular tests and provide treatment opportunities.
Conclusion
Breast cancer therapy has undergone a paradigm shift as a result of the emergence of precision medicine, which aims to use the distinguishing biological markers present in every tumor to guide the management process. Techniques such as receptor testing, molecular and genetic profiling can be useful in guiding the application of targeted therapy, hormonal therapy, immunotherapy, among others.
FAQs
1. Could precision medicine be applied to advanced breast cancer?
Molecular and receptor testing might be especially helpful in advanced cases in choosing appropriate systemic therapy.
2. Is it possible for breast cancer to vary its molecular profile?
Yes, the malignant cells can change their molecular features during the course of the disease and/or under the influence of therapy. Thus, in some cases, testing again could prove beneficial.
References
- Bai, J., Gao, Y., & Zhang, G. (2025). The treatment of breast cancer in the era of precision medicine. Cancer Biology & Medicine, 22(4), 322-347. Https://pubmed.ncbi.nlm.nih.gov/40269562/
- Valencia, O. M., Samuel, S. E., Viscusi, R. K., Riall, T. S., Neumayer, L. A., & Aziz, H. (2017). The role of genetic testing in patients with breast cancer: a review. JAMA surgery, 152(6), 589-594. Https://www.researchgate.net/publication/316266476_The_Role_of_Genetic_Testing_in_Patients_With_Breast_Cancer_A_Review
- Ellisen, L. W., & Haber, D. A. (1998). Hereditary breast cancer. Annual review of medicine, 49(1), 425-436. Https://oamonitor.ireland.openaire.eu/rfo/sfi_rfo/search/publication?pid=10.1146%2Fannurev.med.49.1.425
- Papalexis, P., Georgakopoulou, V. E., Drossos, P. V., Thymara, E., Nonni, A., Lazaris, A. C., … & Thomopoulou, G. E. (2024). Precision medicine in breast cancer. Molecular and clinical oncology, 21(5), 78. Https://www.spandidos-publications.com/10.3892/mco.2024.2776
- Yan, J., Liu, Z., Du, S., Li, J., Ma, L., & Li, L. (2020). Diagnosis and treatment of breast cancer in the precision medicine era. Precision Medicine, 53-61. https://pubmed.ncbi.nlm.nih.gov/32710314/
