The development of breast cancer is associated with many biological processes, and knowing the biological process can be useful for choosing the right treatment to treat the condition. For instance, in case of hormone receptor-positive and HER2-negative breast cancer, estrogens could stimulate proliferation of cancerous cells. However, as the tumor advances, hormonal therapy cannot be enough to inhibit its growth. This is where palbociclib comes into play.
What Is HR-Positive, HER2-Negative Breast Cancer?
Breast cancer HR+/-HER2- is a kind of breast cancer wherein the cancerous cells contain estrogen receptors, progesterone receptors, or both, but do not have high HER2. Hormonal stimulation may lead to the growth of the cancerous cells; therefore, endocrine therapy is a key factor in treating this form of cancer. Yet, at times, there may be cancers that will develop resistance to endocrine therapy. For patients like this, an inhibitor of the CDK4/6, may be taken with endocrine therapy.
Why Do HR-Positive Breast Cancer Cells Continue to Grow?
The process of cell division is characterized by a well-controlled mechanism in which CDK4 and CDK6 play a key role in facilitating the progression of a cell from one phase of the cell cycle to another. In breast cancer, hormonal regulation can increase the expression of such proteins, thereby increasing the ability of these cells to proliferate. However, targeting CDK4/6 could inhibit the cell proliferation process.
What Is Palbociclib?
The medicine is a CDK4/6 inhibitor used to treat certain patients with breast cancer characterized by HR positivity, HER2 negativity, and metastatic advanced stage. This capsule does not kill the cells but hinders the process needed for the cells’ life cycle. Doctor’s recommended this medicine in combination with endocrine therapy to help slow cancer-cell growth and control disease progression.
How Does The Capsule Help Control Breast Cancer Cell Growth?
This drug is known to block CDK4 and CDK6, which are proteins whose function is to assist in the progression of cancer cells within the cell cycle and division. Blocking these proteins makes it hard for cancer cells to progress from the growth phase to the DNA replication phase, hence slowing down the division process. Also, when Palbociclib is used with endocrine treatment, it works complementary to each other.
When Is The Medicine Used?
The therapy can be used by selected patients with advanced or metastatic breast cancer, who have the following criteria:
- HR+ breast cancer
- HER2- breast cancer
- Advanced or metastatic disease
It is usually administered in combination with hormonal treatment and not on its own. However, the decision to use it will depend on many factors including menopausal status, previous treatments, disease progression, tolerability, and general condition of the patient.
What Are the Benefits of The Capsule?
The use of the medication can be seen as an innovative approach to inhibit cancer cells from dividing. The capsule, in combination with endocrine therapy, helps utilize both the complementary biological approaches at once. The advantages are:
- CDK4/6-mediated cycle progression inhibition.
- Utilization of complementary hormonal approach.
- A well-established approach for advanced HR-positive, HER2-negative cases.
- Possibility to slow down the progression of disease in eligible patients.
- Mechanism-based treatment approach.
The treatment response differs from patient to patient, which makes periodic evaluation necessary.
What Are the Possible Side Effects Caused By The Medicine?
Since CDK4/6 proteins also function in healthy cells, the capsule can influence the formation of blood cells. Neutropenia is among the most common side effects associated with the treatment, which might make patients more vulnerable to infections. Among other possible reactions are:
- Fatigue
- Anemia
- Thrombocytopenia
- Nausea
- Diarrhea
- Stomatitis
- Decreased appetite
- Hair thinning
- Infections
Fever and other signs of infection need to be reported right away.
Which Brands Contain Palbociclib?
It is manufactured under various brand names in accordance with different countries and manufacturers. These include:
Dosage of the medicine should be strictly observed, and any variation of the product/dosage should be consulted with the healthcare provider.
What Monitoring Is Needed During Treatment?
Monitoring during therapy is vital for safety, identification of any changes in blood cell counts, and modification of the treatment program.
- The CBC test is always performed before the therapy and during the process of therapy.
- White blood cells and neutrophils are evaluated for detecting neutropenia and decreasing the risks associated with infections.
- Hemoglobin levels may be assessed for possible anemia.
- Platelets may be evaluated for detecting low levels.
- Symptoms such as fever, chills, sore throat, or others associated with infections need to be reported.
- Physicians will evaluate the tolerance of the therapy and worsening or persistent symptoms.
- Clinical assessments and necessary tests may be conducted to determine the effectiveness of the therapy.
- If blood counts drop substantially, the physician may stop the therapy temporarily or modify the dosage of the emedication.
What Is the Future of Targeted Therapy in Breast Cancer?
The development of CDK4/6 inhibitors has increased the efficacy of targeted therapy in individuals with HR-positive breast cancer. The future studies will focus on the most optimal application sequence of the drugs, as well as on their combination with other agents that can be used to treat breast cancer. The identification of cancer-specific biomarkers and mutations through the further research can become helpful in predicting whether particular patients can receive certain targeted treatment options.
Is The Capsule Interact With Other Medicines?
It has potential interactions with certain drugs and other substances; hence, it is essential to assess the current therapies with the healthcare provider to get safe and effective therapy.
- Let the doctor know about all the prescription medications, over-the-counter medications, vitamins, and herbal supplements that are taking.
- Medicines that act on the enzymes involved in the metabolism of the medication can either raise or lower Palbociclib levels in the body.
- Some therapies can raise the chances or intensity of adverse reactions associated with this capsule.
- Grapefruits and grapefruit juice must be avoided when undergoing the treatment.
- Never start, discontinue, or alter the medicine or any supplement before consulting the prescribing physician.
- The physician will either reduce the dosage or prescribe a substitute drug in case there is any significant interaction.
Conclusion
The medicine has an integral part to play in the treatment of certain cases of advanced/metastatic breast cancer that have positive human epidermal growth factor receptor 1/2 negative status. This capsule works by inhibiting the function of cyclin-dependent kinases 4 and 6, which causes inhibition of cell cycle progress. Also, the side effect of abnormal blood counts such as neutropenia needs to be monitored regularly to avoid complications during the treatment.
FAQs
1. Does the medicine cause hair problems?
Hair loss or hair thinning may happen, but the extent differs from one individual to another.
2. Is the capsule be taken if someone is already on endocrine therapy?
Yes, the applicability of this medicine is based on the clinical scenario and the choice of the oncologist.
References
- Huppert, L. A., Gumusay, O., Idossa, D., & Rugo, H. S. (2023). Systemic therapy for hormone receptor‐positive/human epidermal growth factor receptor 2‐negative early stage and metastatic breast cancer. CA: a cancer journal for clinicians, 73(5), 480-515. Https://acsjournals.onlinelibrary.wiley.com/doi/full/10.3322/caac.21777
- Ballinger, T. J., Meier, J. B., & Jansen, V. M. (2018). Current landscape of targeted therapies for hormone-receptor positive, HER2 negative metastatic breast cancer. Frontiers in Oncology, 8, 373869. Https://pubmed.ncbi.nlm.nih.gov/30148117/
- Kim, E. S., & Scott, L. J. (2017). Palbociclib: a review in HR-positive, HER2-negative, advanced or metastatic breast cancer. Targeted oncology, 12(3), 373-383. Https://pubmed.ncbi.nlm.nih.gov/28488183/
- Wang, W., Lei, W., Fang, Z., Jiang, R., & Wang, X. (2024). Efficacy, safety, and predictive model of Palbociclib in the treatment of HR-positive and HER2-negative metastatic breast cancer. BMC cancer, 24(1), 1. Https://www.researchgate.net/publication/377080696_Efficacy_safety_and_predictive_model_of_Palbociclib_in_the_treatment_of_HR-positive_and_HER2-negative_metastatic_breast_cancer
- Clark, A. S., Karasic, T. B., DeMichele, A., Vaughn, D. J., O’Hara, M., Perini, R., … & O’Dwyer, P. J. (2016). Palbociclib (PD0332991)—a selective and potent cyclin-dependent kinase inhibitor: a review of pharmacodynamics and clinical development. JAMA oncology, 2(2), 253-260. https://www.ovid.com/journals/jamaon/abstract/10.1001/jamaoncol.2015.4701~palbociclib-pd0332991a-selective-and-potent-cyclin-dependent?redirectionsource=fulltextview
