Ovarian cancer develops when cells in or near the ovaries grow uncontrollably, forming tumors. It is a significant health concern, with approximately 1.1% of women having a lifetime risk of developing the disease. A specific subtype, HER2-positive ovarian cancer, involves a particular protein that influences how these cancer cells behave. Understanding this subtype is becoming increasingly important for guiding treatment decisions.
Understanding HER2 in Ovarian Cancer
HER2, or Human Epidermal Growth Factor Receptor 2, is a protein found on the surface of cells throughout the body. Its normal function involves regulating cell growth, division, and repair by transmitting signals from outside the cell to its interior. HER2 belongs to a family of four receptors, activating by partnering with other members to initiate cellular signaling pathways. These pathways play a role in normal cell development and proliferation.
In cancer, the gene responsible for producing the HER2 protein, known as ERBB2, can undergo amplification or overexpression. This means there are too many copies of the HER2 gene, leading to an excessive amount of HER2 protein on the cell surface. This overabundance of HER2 receptors causes uncontrolled signaling within the cell, telling it to divide and grow without regulation. This unchecked cell division contributes directly to tumor growth and progression. HER2 overexpression drives this uncontrolled growth, making it a specific target for therapies designed to block these signals in HER2-positive cancers.
Identifying HER2 Positive Ovarian Cancer
Detecting HER2 overexpression or gene amplification in ovarian cancer is an important step in determining treatment. This testing helps identify patients whose tumors might respond to therapies that specifically target the HER2 pathway. Methods used to assess HER2 status involve analyzing tissue samples from the patient’s tumor.
One common method is immunohistochemistry (IHC), which uses antibodies to detect the HER2 protein in tissue sections. The intensity and pattern of staining are scored to determine the level of HER2 protein expression. Another technique is fluorescence in situ hybridization (FISH), which identifies if the ERBB2 gene is amplified, meaning there are extra copies of the gene within the cancer cells. FISH uses fluorescent probes that bind to the ERBB2 gene, allowing visualization and counting of gene copies under a microscope. Determining HER2 status through these methods guides clinicians in selecting targeted treatment strategies.
Targeted Treatment Options
Targeted therapies for HER2-positive ovarian cancer aim to interfere with the HER2 protein’s ability to promote cancer cell growth. These treatments are more precise than traditional chemotherapy, directly addressing molecular changes in cancer cells. One type of targeted therapy involves monoclonal antibodies, such as trastuzumab.
Trastuzumab is a monoclonal antibody that binds to the HER2 protein on cancer cell surfaces, blocking signals that tell cells to grow and divide. It can also trigger the body’s immune system to attack and destroy HER2-overexpressing cells. While effective in some HER2-positive cancers, trastuzumab’s effectiveness as a single agent in ovarian cancer has shown varied response rates in studies.
Newer approaches include antibody-drug conjugates (ADCs), which combine a monoclonal antibody’s targeting ability with a potent chemotherapy drug. These ADCs deliver the chemotherapy agent directly to HER2-expressing cancer cells, minimizing damage to healthy cells and improving treatment outcomes. Targeted therapies are often used in combination with traditional chemotherapy regimens to enhance their effectiveness against HER2-positive ovarian cancer.