Breast Cancer Drugs
Your doctor will determine
your breast cancer treatment after considering multiple factors like the
specific type and stage of the cancer. According to the Mayo
Clinic, many women diagnosed with breast cancer
undergo surgery as a part of their treatment. There are also numerous drugs for
breast cancer that may be used before, after, or in some cases, instead of
There are many different
options, and the complex decision-making may be very overwhelming.
Communicating with your doctor is key.
Trastuzumab, more commonly known by its brand name,
Herceptin, is a targeted therapy for breast cancer. According to the American Cancer Society,
Herceptin can stop the growth and spread of breast cancer by stopping the human
epidermal growth factor receptor 2 (Her-2/neu) actions on cancer cells.
Herceptin is given through an IV. It’s most often used in combination with
chemotherapy or hormone therapy. It’s known as a targeted therapy because it specifically
attaches to the protein that is driving the growth of Her-2/neu positive breast
cancers. This attachment slows growth of
the cancer by blocking one of the signals for cancer cells to divide and labels
only those cells for killing by the patient’s own immune system. It does not
damage any other cells.
The Herceptin regimen usually calls for an initial 90-minute
dose. Follow-up dosages of shorter duration happen a week to three weeks later.
Studies haven’t yet proven the most effective duration. Herceptin can cause
negative side effects for some patients. The U.S. Food and Drug Administration
(FDA) requires that patients be screened for proper heart function before undergoing
Herceptin treatment. Also, if you
already have lung disease like asthma or COPD or if the breast cancer has
significantly invaded your lungs, there is an increased possibility of lung damage.
Your doctor should go over side effects that may occur before you start this
Like Herceptin, Tykerb targets the HER2 receptor. But unlike
Herceptin, it interferes with the action of the receptor inside the cell rather
than blocking its activation outside the cell.
Because of this difference, Tykerb only slows down tumor growth. It does
not label the cells for removal by the patient’s immune system. It’s approved for the treatment of advanced
metastatic breast cancer. But it’s typically reserved for women who have
already tried Herceptin without positive results.
Side effects of Tykerb reflect this somewhat more
generalized activity and include vomiting, diarrhea, nausea, fatigue, rash,
mouth sores, and pain in the hands and feet (neuropathy).
Avastin is a drug therapy that starves cancer cells by
preventing the tumor cells from communicating with nearby blood vessels and may
prevent the tumor from connecting to the blood supply. The cancer cells die without
a blood supply bringing fresh oxygen and nutrients to the tumor.
Side effects of bevacizumab include fatigue, high blood
pressure, blood clots, headaches, heat damage, and mouth sores.
The U.S. Food and Drug Administration
approved bevacizumab in 2004. In 2008, it was approved for use in
metastatic breast cancer. There was some controversy around this. The panel
advised against approval because while the drug may help slow the growth of
cancer cells, research hasn’t been able to show the drug can increase a
person’s survival rate. In 2011, the FDA revoked the use of the drug in advanced
Doctors can still prescribe it for “off-label use,” but insurance
companies are less likely to cover it. In 2014, the FDA approved use of
bevacizumab in patients with aggressive and late-stage cervical cancer.
to the American Cancer Society, dozens of chemotherapy
drugs are approved by the FDA for the treatment of breast cancer. Certain
chemotherapy drugs for breast cancer are used more commonly than others.
- Cyclophosphamide (Cytoxan) blocks the copying of DNA in cancer
cells, inhibiting their growth.
- Docetaxel (Taxotere) interferes with cell division, slowing the
- Doxorubicin (Adriamycin) is an anthracycline drug, which is
derived from strep bacteria and is one of the more effective broad spectrum
- Fluorouracil (Adrucil) blocks enzymes required for DNA production
by cancer cells.
- Methotrexate (Trexall) blocks an enzyme needed by cancer cells
(and other rapidly dividing cells) to live.
- Paclitaxel (Taxol), a taxane like docetaxel, disrupts cell
regimens often combine the agents above and others. Doses typically include two
or more drugs to enhance their power and to decrease the chance that the cancer
will return. The expectation is that combination therapy will allow many women
with breast cancer to live longer.
combination that is gaining favor among clinicians is aimed at women whose
estrogen receptor-negative breast cancer has spread to the lymph nodes. For
them, many oncologists prescribe an anthracycline such as cyclophosphamide followed
by a taxane (docetaxel or paclitaxel). This combination has been shown to
reduce the chance of a relapse and to provide a longer life for the women who
similarly population-specific treatment is for women with Her-2/neu positive
cancer. A course of chemotherapy used together with Herceptin (trastuzumab)
significantly decreases the risk of recurrence and even improves chances for
effects may occur with any chemotherapy drug. Side effects will differ depending
on differences in regimens, drugs, and the individual. Common side effects
you begin any chemotherapy, your medical team should go over side effects that
may occur and suggestions to combat or mitigate them.
This synthetic hormone decreases the risk of recurrence in women with either early-stage or
metastatic hormone receptor-positive breast cancer. Tamoxifen blocks estrogen,
which reduces the chances for recurrence or new tumor development. It’s
appropriate for both pre- and postmenopausal women who have hormone
receptor-positive breast cancer. Tamoxifen won’t work for breast cancers that
are not estrogen-sensitive or for women who do not have an enzyme, CYP2D6,
which activates the drug.
Tamoxifen is usually given daily for five years. So far this
appears to be the optimal length of treatment. Side effects from it are usually
irregular periods, vaginal discharges, and hot flashes. There is also a low
risk for leg or lung blood clots and different kinds of uterine cancer.
Postmenopausal hormone receptor-positive women are the prime
candidates for aromatase inhibitor (AI) therapy. AI drugs include:
All three work by prompting a significant drop in your
body's estrogen levels. AIs can work as well as tamoxifen and are often used in
combination with it. AI drugs can be used alone if a woman cannot take
tamoxifen. Many cancer specialists recommend that adjuvant therapy for hormone
receptor-positive breast cancer in postmenopausal women include an aromatase
inhibitor to reduce the chances for recurrence.
Possible long-term effects of the lowered estrogen caused by
both tamoxifen and AI therapy could put you at greater risk of osteoporosis. Your
doctor may monitor your bone mineral density while you're taking the
medication. Lower estrogen levels also may lead to vaginal dryness and