Human epidermal growth factor 2, or HER2, is a protein that directs human cells how to grow as well as when not to develop. Occasionally, an arbitrary genetic mutation or excess copies of the HER2 gene cause these cells to proliferate uncontrollably.
This form of cancer is referred to as “HER2-positive.” Compared to other cancers, it develops faster, making it more aggressive. In addition, stomach, ovarian, bladder, and gastrointestinal malignancies can all be HER2 positive.
It’s unknown why HER2-positive cases of breast cancer arise or who most is at risk, but they account for about 20% of all diagnoses.
Symptoms that One May Have
This subtype of cancer may not exhibit overt symptoms, similar to many other types of the disease. When it happens, breast cancer that is HER-2 positive may have these typical symptoms:
- Alterations to the dimensions, form, or outline of the breasts.
- A lump or cluster of mass that might have the feel of a pea.
- A lump or thickening in the breast or underarm that lasts throughout your menstrual cycle.
How is it Diagnosed?
The signs of HER2 positive breast cancer are similar to those of other forms of the disease. Frequently, a patient discovers a lump or a regular mammography reveals one. In addition to being HER2 positive, inflammatory breast cancer may trigger individuals to have additional breast alterations, such as rash. To ascertain HER2 status, two tests are performed:
- Fluorescence in situ hybridization (FISH) test: This test can be run if the findings of an IHC are unclear, particularly if the IHC score is two. This pathological method examines the HER2 gene to see if more than one copy is present. We refer to this as HER2 amplification. Either positive or bad outcomes are possible with these.
- IHC testing, or immunohistochemistry: This test determines the quantity of HER2 present on the cell’s surface. HER2 negative tumors get a score of zero or one. Two is considered a borderline diagnosis. A cell is HER2 positive if its score is three.
Available Treatment Options
The size of the tumor determines how HER2 positive breast cancer is treated. Patients whose tumors are less than 2 cm in size and do not include lymph nodes will initially have surgery, then chemotherapy as well as a single antibody called trastuzumab (Herceptin) that targets the HER2 protein.
Patients will undergo chemotherapy in combination with one or two types of chemotherapy and two antibodies (trastuzumab in addition to an older antibody called pertuzumab or Perjeta) if a tumor is greater than two cm and has spread to neighboring lymph nodes.
Chemotherapy can drop blood counts, raise the risk of infection, cause hair loss, induce nausea and vomiting, and produce neuropathy, which is a temporary but occasionally permanent numbness in the hands and feet.
Conclusion
Developing novel and more effective treatments for this incredibly sensitive target, HER2+, is the subject of many studies in the preclinical, translational, and clinical domains.
Targeting HER2+ has advanced due to the use of antibody-drug conjugates (ADCs) and the optimization of their efficiency by modification of the linkers, payload, or antibody scaffold. Creating bispecific antibodies is a further strategy that maximizes efficiency by attaching to two distinct HER2+ epitopes.
In the same way that immunotherapy has proven beneficial for triple-negative breast cancer (TNBC), efforts are now being made to stimulate the immune system in HER2+ diseases.
