HER2 positive breast cancer is a distinct subtype characterized by an excess of the human epidermal growth factor receptor 2 (HER2) protein on the surface of cancer cells. This protein acts like a growth signal, leading to more aggressive tumor growth and spread. This specific characteristic also makes it possible to develop treatments that directly target the HER2 protein.
Understanding Available Therapies
Treatments for HER2 positive breast cancer involve a combination of approaches. Targeted therapies block the HER2 protein. These include monoclonal antibodies like trastuzumab and pertuzumab, which bind to HER2 receptors on cancer cells, preventing them from receiving growth signals and also helping the immune system recognize and attack cancer cells.
Another type of targeted drug is ado-trastuzumab emtansine (T-DM1), an antibody-drug conjugate that links trastuzumab with a chemotherapy drug, delivering the chemotherapy directly to HER2-positive cancer cells. Fam-trastuzumab deruxtecan-nxki is a newer antibody-drug conjugate that combines trastuzumab with a chemotherapy drug, guiding it to HER2-positive cells while minimizing harm to healthy tissue. Tyrosine kinase inhibitors (TKIs) like neratinib also block HER2 and other related proteins that contribute to cancer cell growth.
Chemotherapy plays a supporting role, often administered alongside targeted therapies. These drugs kill rapidly dividing cells throughout the body, including cancer cells. Combining trastuzumab with chemotherapy has been shown to significantly reduce the risk of breast cancer recurrence. Regimens often involve multiple drugs given in cycles with rest periods.
Immunotherapy is an evolving area of cancer treatment that harnesses the body’s own immune system to fight cancer cells. While immune checkpoint inhibitors are currently approved for other breast cancer subtypes, their role in HER2 positive breast cancer is under investigation. Research indicates that HER2-positive breast cancers may have characteristics that make them responsive to immunotherapy. Studies are exploring various immunotherapeutic strategies.
Surgery is a primary treatment modality aimed at removing the primary tumor and potentially affected lymph nodes. Options include lumpectomy, which removes the tumor and a small amount of surrounding tissue, or mastectomy, which removes the entire breast. The choice of surgical procedure depends on factors like tumor size, location, and patient preferences.
Radiation therapy uses high-energy beams to destroy any remaining cancer cells in a localized area, such as the breast or nearby lymph nodes, after surgery. It can also be used to target specific areas where cancer has spread. Postoperative radiation therapy can reduce the risk of local recurrence and improve overall survival for patients with early-stage HER2 positive breast cancer.
Tailoring the Treatment Plan
The treatment for HER2 positive breast cancer is a highly individualized process, with therapies often combined and sequenced to achieve the best outcome. Neoadjuvant therapy is given before surgery, typically to shrink the tumor for easier or less extensive removal. This approach is common for many with HER2 positive breast cancer.
Adjuvant therapy is administered after surgery to eliminate any remaining cancer cells, thereby reducing the risk of recurrence. After neoadjuvant therapy and surgery, patients often receive adjuvant HER2-targeted therapy. This strategic sequencing helps to target cancer cells at various stages of the disease.
A personalized treatment plan is developed by considering multiple factors beyond just the HER2 status. The stage of the cancer, including tumor size and whether it has spread to lymph nodes or distant sites, significantly influences decisions. Other tumor characteristics, such as hormone receptor status, also guide treatment choices, as hormone receptor-positive HER2 positive cancers may also benefit from hormone therapy.
The patient’s overall health, age, and any co-existing medical conditions are also carefully evaluated to ensure the chosen therapies are well-tolerated and effective. Patient preferences and lifestyle considerations are integrated into the decision-making process. Treatment decisions are typically made through a collaborative effort involving a multidisciplinary team of specialists, including oncologists, surgeons, and radiation oncologists, to ensure a comprehensive and coordinated approach.
Managing the Treatment Journey
Undergoing treatment for HER2 positive breast cancer involves navigating various practical aspects and potential side effects. Common side effects can vary depending on the specific therapies received. Chemotherapy, for example, can lead to fatigue, nausea, hair loss, and a lowered blood count, increasing the risk of infection. Some targeted therapies, like trastuzumab, can have specific cardiac effects, such as weakness of the heart muscle, though this often resolves with treatment adjustment. Radiation therapy may cause skin changes and fatigue in the treated area.
Doctors closely monitor the effectiveness of treatment through various methods. Imaging scans, such as CT, MRI, or PET scans, help assess tumor size and response to therapy. Blood tests can also provide information about the body’s response to treatment and overall health. Based on these assessments, the treatment plan may be adjusted to optimize outcomes and manage side effects.
Supportive care plays a significant role in managing the treatment journey. This includes managing symptoms like pain or nausea, providing nutritional support, and addressing emotional well-being through counseling or support groups. The aim is to help patients maintain their quality of life throughout treatment.
After completing active treatment, long-term follow-up is necessary to monitor for any signs of cancer recurrence. This typically involves regular check-ups, physical examinations, and imaging scans. Ongoing monitoring helps ensure that any potential recurrence is detected early, allowing for prompt intervention.