Biological therapy is a treatment that uses drugs to improve the way your body’s immune system fights disease. Your immune system is your body’s natural defense against disease. A healthy and strong immune system can potentially detect the difference between healthy cells and cancer cells. Biological therapy attempts to strengthen and improve the immune system so that it can fight the cancer more effectively.
Interferon is the most common form of biological therapy. Interferons interfere with the division of cancer cells and can slow their growth. There are several types of interferons, and they are normally produced in the body. For the use of biological therapy, interferons are made in the laboratory. Other possible biological therapies include interleukin and monoclonal antibodies (MABs), such as
Herceptin
(combined with chemotherapy). New biological therapies recently approved by the FDA include:
-
Avastin
(used in combination with paclitaxel for patients who have not received chemotherapy for metastatic breast cancer)
-
Lapatinib
(used in combination with
capecitabine
(Xeloda) for metastatic breast cancer)
These newer therapies have shown great promise, but pose some medical risks. Discuss them with your doctor.
Most biological therapies are given by injection into a vein. They are frequently given in combination with
chemotherapy
or
radiation therapy
.
Side Effects
Possible side effects include:
- Red, sore area where injection was given
- Flu-like symptoms—fever, chills, gastrointestinal upset
- Fatigue
- Allergic reactions—cough, wheezing, skin rash
-
Confusion, disorientation,
depression
- Interleukin therapy is generally given in the hospital because it can cause severe changes in blood pressure.
Special Considerations
These treatments can cause extreme fatigue. It is important to get as much rest as possible when your body is fighting cancer. Talk with your doctor about how best you can minimize side effects and the discomforts that come with treatment.
To date, vaccines and other immunotherapies have not been effective in killing breast cancer. There is always hope that this may be effective in some patients, and scientists feel that the greatest benefit from vaccinations against breast cancer may be in those patients who have a predisposition to developing the disease (most likely related to a family history or a genetic mutation in a gene such as BRCA-1 or BRCA-2).
Hormonal Therapy
Hormonal therapy is designed to take advantage of the fact that many breast cancers are "estrogen sensitive." In other words, estrogen—a hormone—binds to the "estrogen sensitive" cells and stimulates them to grow and divide. Anti-estrogen drugs, like
tamoxifen
, prevent the binding of estrogen. This stops the cells from growing and, in doing so, prevents or delays breast cancer recurrence.
Newer agents, like aromatase inhibitors, may be more effective than tamoxifen in both early and advanced stages of breast cancer. Examples of aromatase inhibitors include:
-
Anastrozole
(Arimidex)
-
Exemestane
(Aromasin)
-
Letrozole
(Femara)
In some cases, these agents are inappropriate (eg, in women who are premenopausal or who cannot tolerate aromatase inhibitors). Tamoxifen may be used instead of a newer agent. There is another type of hormonal therapy drugs called luteinizing hormone-releasing hormone (LHRH) agonists, which works by blocking how much estrogen the body makes. LHRH agonists may reduce the risk of cancer recurrence in premenopausal women who have early stage breast cancer. In some cases, it is used along with tamoxifen.
Side Effects
Hormonal therapy to treat breast cancer will cause
menopause
, including hot flashes, night sweats, change in mental status, and
infertility
. Managing these side effects may be difficult for cancer patients because hormone replacement therapy (used to manage menopause in healthy women) is not an option. It would counteract the effects of the anti-estrogen agents.
In addition to menopausal symptoms, other side effects can occur, such as:
- Bone, muscle, and joint pain (aromatase inhibitors, tamoxifen, and LHRH agonists)
- Weakened bones (aromatase inhibitors, LHRH agonists)
-
Blood clots,
stroke
,
uterine cancer
,
cataracts
(tamoxifen)
- Fast or irregular heartbeat (LHRH agonists)
Make sure to talk to your doctor about all medicines you are taking. Some medications, when mixed, can cause problems. For example, when tamoxifen and certain antidepressants are taken together, this may increase the risk of death from breast cancer.