According to BreastCancer.org, targeted therapies are treatments that single out specific characteristics of cancer cells, such as a protein that allows the cancer cells to grow in a rapid or abnormal way. Targeted therapies are generally less likely than chemotherapy to harm normal, healthy cells. Some targeted therapies are antibodies that work like the antibodies made naturally by our immune systems. These types of targeted therapies are sometimes called immune targeted therapies.
There are currently three targeted therapies doctors use to treat breast cancer:
Herceptin (chemical name: trastuzumab) works against HER2-positive breast cancers by blocking the ability of the cancer cells to receive chemical signals that tell the cells to grow.
Tykerb (chemical name: lapatinib) works against HER2-positive breast cancers by blocking certain proteins that can cause uncontrolled cell growth.
Avastin (chemical name: bevacizumab) works by blocking the growth of new blood vessels that cancer cells depend on to grow and function.
Pros and Cons of Herceptin
Herceptin slows down or stops the growth of breast cancer cells – even with metastatic disease. There are three tests used to determine whether a patient has the particular cancer (HER2-positive) that will respond to this drug. First, there is the IHC test that measures HER2 receptor protein. Second, the FISH test counts copies of the HER2 gene and third, the SPoT-Light HER2 CISH test that counts HER2 copy genes as well.
Herceptin is given intravenously. When first administered, the patient will be monitored closely to observe any adverse reactions. What about side effects?
Common side effects:
Fever
Chills
Muscle aches
Nausea
Less common side effects:
Mild heart damage
Severe heart damage
Lung reactions
If heart problems arise, the doctor assigned will discontinue Herceptin and begin heart-strengthening medications. The possibility of heart problems is the reason why doctors usually give the patient a thorough checkup to evaluate this organ as well as the lungs.
Pros and Cons of Tykerb
As indicated by BreastCancer.org, Tykerb works inside the cancer cell by interfering with certain proteins, called kinases. Left untreated, kinases can stimulate an uncontrolled growth of cancer cells. Tykerb is used in regards to advanced stage breast cancer that have stopped responding to other medications and with post-menopausal women with advance-stage cancer. The IHC and FISH tests are the two tests that are used to determine whether this drug can be used in a particular patient’s treatment.
The side effects for Tykerb are usually mild and not life-threatening. Listed below are known side effects for this drug.
Common side effects:
Diarrhea
Vomiting
Fatigue
Less common side effects:
Mild heart damage
Doctors usually adjust the dosage to control these symptoms. With heart damage and diarrhea, this medication will be stopped. Heart-strengthening medication will be administered for any heart problem developed.
Pros and Cons of Avastin
Avastin works by blocking any cancer cell growth of new blood vessels, which, in turn, starves the cancer of nutrients. The growth of new blood vessels into a tumor is called angiogenesis. This medication blocks the protein made during this growth process – which is why Avastin is called an anti-angiogenic. Avastin can also change blood vessels already feeding the cancer in ways that make it harder for the cancer to survive and more vulnerable to chemotherapy.
Avastin is an immune targeted therapy. It is given intravenously and monitored initially for any allergic reactions. Listed below are known side effects.
Common side effects:
Nosebleeds
High blood pressure
Extra protein in urine
Less common side effects:
Weakness
Pain
Diarrhea
Blood clots
Slow wound healing
Perforation of intestines
Risk of stroke
Risk of heart problems
Risk of kidney malfunction
Low white blood count
If you experience any of the above side effects, please contact your doctor immediately. Remember, these medications are just additional options in breast cancer treatment. Before making any choice regarding treatment, your doctor should discuss, in detail, any options available.
Resource: BreastCancer.org
Dita Faulkner is a freelance writer that has three nieces and four nephews of whom she tries to be a positive influence by word and deed.