How does Herceptin work for breast cancer?
In 1998, the Food and Drug Administration (FDA) approved the medication for treating metastatic breast cancer with an overexpression of the human epidermal growth factor receptor 2 (HER2) gene.
In 2006, the FDA approved Herceptin for use in people with early-stage breast cancer, alongside standard breast cancer chemotherapy.
In 2014, a study reported that combining Herceptin with chemotherapy increased the 10-year overall survival rate among people with HER2-positive, operable breast cancer from just over 75 percent to 84 percent.
Herceptin helps treat some kinds of cancer, including breast cancer.
Herceptin is a monoclonal antibody, and it interferes with HER2.
Doctors use monoclonal antibodies to treat some types of cancer, either alongside chemotherapy or alone.
Cells produce proteins, and a monoclonal antibody recognizes and attaches itself to a particular protein.
Human epidermal growth factor receptor proteins promote the growth, adhesion, migration, differentiation, and survival of cells.
These proteins occur at high levels in cancer cells, which may explain why cancer cells divide so rapidly.
Different antibodies work in different ways, depending on their target protein. Doctors use specific antibodies to treat certain types of cancer.
The antibodies involved in cancer therapies have various ways of attacking cancer cells, including:
- triggering the immune system to attack the unwanted cells
- putting up a barrier to signals that tell the cancer cells to divide
- blocking molecules that prevent immune function
- carrying radiation or cancer drugs to the cancer cells
HER2 is a type of human epidermal growth factor receptor that can play a role in the development of breast cancer.
The task of this type of receptor is transmitting molecular signals to the insides of cells from the surface. These signals switch genes on and off.
In some people, the HER2 receptor is faulty. Its on switch never goes off, so breast cells endlessly reproduce. Cancer results from this uncontrolled cell division.
When a protein overexpresses, the body produces too much of it. This often contributes to developing cancer.
Herceptin sticks to the HER2 protein, and it prevents the epidermal growth factor from entering cancer cells. This is how Herceptin prevents breast cancer cells from growing in a way that the body cannot control.
People should only take Herceptin if they have overexpression of HER2. It does not benefit individuals who do not have this type of breast cancer.
Among newly diagnosed cases of breast cancer, around 10–20 percent are positive for HER2. A range of lab tests can determine whether a person has too much HER2.
A healthcare professional will administer Herceptin, either as a series of intravenous infusions or subcutaneous injections, which are injections under the skin, at intervals of 1–3 weeks.
Currently, people with early-stage breast cancer undergo a 1-year course of Herceptin.
Studies have shown that treatment lasting 1 year is more beneficial than that lasting only 6 months. Extending Herceptin therapy beyond 1 year does not seem to have any benefits.
When the cancer has spread to other organs or tissues, a doctor may recommend using pertuzumab, Herceptin, and paclitaxel together.
In treating this type of cancer, Herceptin is only helpful until it no longer exhibits a controlling effect on cell reproduction.
Herceptin can cause congestive heart failure.
In rare circumstances, Herceptin can damage heart cells and lead to congestive heart failure.
As a result, people usually require a heart assessment before they can use this medication, and monitoring should continue throughout treatment. People with a preexisting heart condition should not take Herceptin.
This is the most serious potential side effect. However, most people will recover after stopping use of the drug and that long-term effects are unlikely.
Herceptin might also cause problems in the lungs. In rare cases, a person might experience severe breathlessness, fluid on the lungs, or other symptoms.
If lung-related symptoms occur, contact a physician.
Some doctors have also reported low white blood cell counts in people taking Herceptin. This can be life-threatening, and healthcare professionals may conduct regular white blood cell counts during treatment.
Flu-like symptoms occur in about 40 percent of people who use Herceptin, but these generally become less severe after the first dose.
Other possible side effects of Herceptin include:
- stomach pain
- nausea and vomiting
- a fever
- chest pain
- general aches and pains
Rarely, a person develops an allergic reaction to the drug and experiences breathlessness, itching, and a rash.
However, people generally tolerate Herceptin well. Most do not experience significant side effects. Other medications can relieve a majority of the adverse effects.
Is Herceptin effective for any other diseases?
Herceptin works on a specific target, the HER2 receptor, which limits its effectiveness for treating diseases other than cancer.
Those who have tests showing that they have HER2-positive cancer cells benefit by using Herceptin. Meanwhile, use in other cancers is being studied.Alan Carter, PharmD Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.