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The aim of cancer treatment is to remove all or
as much of the tumor as possible and to prevent the recurrence or
spread of the primary tumor. While devising a treatment plan for
cancer, the likelihood of curing the cancer has to be weighed
against the side effects of the treatment. If the cancer is very
aggressive and a cure is not possible, then the treatment should be
aimed at relieving the symptoms and controlling the cancer for as
long as possible.
Cancer treatment can take many different forms,
and it is always tailored to the individual patient. The decision on
which type of treatment is the most appropriate depends on the type
and location of cancer, the extent to which it has already spread,
the patient's age, sex, general health status and personal treatment
preferences. The major types of treatment are: surgery, radiation,
chemotherapy, immunotherapy, hormone therapy, and bone-marrow
transplantation.
Surgery
Surgery is the removal of a visible tumor and is
the most frequently used cancer treatment. It is most effective when
a cancer is small and confined to one area of the body.
Surgery can be used for many purposes.
- Treatment. Treatment of cancer by surgery involves removal of
the tumor to cure the disease. This is typically done when the
cancer is localized to a discrete area. Along with the cancer,
some part of the normal surrounding tissue is also removed to
ensure that no cancer cells remain in the area. Since cancer
usually spreads via the lymphatic system, adjoining lymph nodes
may be examined and sometimes they are removed as well.
- Preventive surgery. Preventive or prophylactic surgery
involves removal of an abnormal looking area that is likely to
become malignant over time. For example, 40% of the people with a
colon disease known as ulcerative colitis, ultimately die of colon
cancer. Rather than live with the fear of developing colon cancer,
these people may choose to have their colons removed and reduce
the risk significantly.
- Diagnostic purposes. The most definitive tool for diagnosing
cancer is a biopsy. Sometimes, a biopsy can be performed by
inserting a needle through the skin. However, at other times, the
only way to obtain some tissue sample for biopsy is by performing
a surgical operation.
- Cytoreductive surgery is a procedure where the doctor removes
as much of the cancer as possible, and then treats the remaining
with radiation therapy or chemotherapy or both.
- Palliative surgery is aimed at curing the symptoms, not the
cancer. Usually, in such cases, the tumor is so large or has
spread so much that removing the entire tumor is not an option.
For example, a tumor in the abdomen may be so large that it may
press on and block a portion of the intestine, interfering with
digestion and causing pain and vomiting. "Debulking surgery" may
remove a part of the blockage and relieve the symptoms. In tumors
that are dependent on hormones, removal of the organs that secrete
the hormones is an option. For example, in prostate cancer, the
release of testosterone by the testicles stimulates the growth of
cancerous cells. Hence, a man may undergo an "orchiectomy" (removal
of testicles) to slow the progress of the disease. Similarly, in a
type of aggressive breast cancer, removal of the ovaries (oophorectomy)
will stop the synthesis of hormones from the ovaries and slow the
progression of the cancer.
Radiation
Radiation kills tumor cells. Radiation is used
alone in cases where a tumor is unsuitable for surgery. More often,
it is used in conjunction with surgery and chemotherapy. Radiation
can be either external or internal. In the external form, the
radiation is aimed at the tumor from outside the body. In internal
radiation (also known as brachytherapy), a radioactive substance in
the form of pellets or liquid is placed at the cancerous site by
means of a pill, injection or insertion in a sealed container.
Chemotherapy
Chemotherapy is the use of drugs to kill cancer
cells. It destroys the hard-to-detect cancer cells that have spread
and are circulating in the body. Chemotherapeutic drugs can be taken
either orally (by mouth) or intravenously, and may be given alone or
in conjunction with surgery, radiation or both.
When chemotherapy is used before surgery or
radiation, it is known as primary chemotherapy or "neoadjuvant
chemotherapy." An advantage of neoadjuvant chemotherapy is that
since the cancer cells have not been exposed to anti-cancer drugs,
they are especially vulnerable. It can therefore be used effectively
to reduce the size of the tumor for surgery or target it for
radiation. However, the toxic effects of neoadjuvant chemotherapy
are severe. In addition, it may make the body less tolerant to the
side effects of other treatments that follow such as radiation
therapy. The more common use of chemotherapy is adjuvant therapy,
which is given to enhance the effectiveness of other treatments For
example, after surgery, adjuvant chemotherapy is given to destroy
any cancerous cells that still remain in the body.
Immunotherapy
Immunotherapy uses the body's own immune system
to destroy cancer cells. This form of treatment is being intensively
studied in clinical trials and is not yet widely available to most
cancer patients. The various immunological agents being tested
include substances produced by the body (such as the interferons,
interleukins, and growth factors), monoclonal antibodies and
vaccines. Unlike traditional vaccines, cancer vaccines do not
prevent cancer. Instead, they are designed to treat people who
already have the disease. Cancer vaccines work by boosting the
body's immune system and training the immune cells to specifically
destroy cancer cells.
Hormone therapy
Hormone therapy is standard treatment for some
types of cancers that are hormone-dependent and grow faster in the
presence of particular hormones. These include cancer of the
prostate, breast, and uterus. Hormone therapy involves blocking the
production or action of these hormones. As a result the growth of
the tumor slows down and survival may be extended for several months
or years.
Bone marrow transplantation
The bone marrow is the tissue within the bone
cavities that contains blood-forming cells. Healthy bone marrow
tissue constantly replenishes the blood supply and is essential to
life. Sometimes, the amount of drugs or radiation needed to destroy
cancer cells also destroys bone marrow. Replacing the bone marrow
with healthy cells counteracts this adverse effect. A bone marrow
transplant is the removal of marrow from one person and the
transplant of the blood-forming cells either to the same person or
to someone else. Bone-marrow transplantation, while not a therapy in
itself, is often used to "rescue" a patient, by allowing those with
cancer to undergo very aggressive therapy.
Many different specialists generally work
together as a team to treat cancer patients. An oncologist is a
physician who specializes in cancer care. The oncologist provides
chemotherapy, hormone therapy, and any other non-surgical treatment
that does not involve radiation. The oncologist often serves as the
primary physician and coordinates the patient's treatment plan.
The radiation oncologist specializes in using
radiation to treat cancer, while the surgical oncologist performs
the operations needed to diagnose or treat cancer. Gynecologist-oncologists
and pediatric-oncologists, as their titles suggest, are physicians
involved with treating women's and children's cancers respectively.
Many other specialists may also be involved in the care of a cancer
patient. For example, radiologists specialize in the use of x rays,
ultrasounds, computed tomography scans (CT scans), MRI imaging and
other techniques that are used to diagnose cancer. Hematologists
specialize in disorders of the blood and are consulted in case of
blood cancers and bone marrow cancers. The samples that are removed
for biopsy are sent to a laboratory, where a pathologist examines
them to determine the type of cancer and extent of the disease. Only
some of the specialists who are involved with cancer care have been
mentioned above. There are many other specialties, and virtually any
type of medical or surgical specialist may become involved with care
of the cancer patient should it become necessary. |
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CANCER
ALTERNATIVE TREATMENTS
There are a multitude of alternative treatments
available to help the person with cancer. They can be used in
conjunction with, or separate from, surgery, chemotherapy, and
radiation therapy. Alternative treatment of cancer is a complicated
arena and a trained health practitioner should be consulted.
Although the effectiveness of complementary
therapies such as acupuncture in alleviating cancer pain has not
been clinically proven, many cancer patients find it safe and
beneficial. Bodywork therapies such as massage and reflexology ease
muscle tension and may alleviate the side effects such as nausea and
vomiting. Homeopathy and herbal remedies used in Chinese traditional
herbal medicine have also been shown to alleviate some of the side
effects of radiation and chemotherapy and are being recommended by
many doctors.
Certain foods including many vegetables, fruits
and grains are believed to offer protection against various cancers.
However, isolation of the individual constituent of vegetables and
fruits that are anti-cancer agents has proven difficult. In
laboratory studies, vitamins such as A, C and E, as well as
compounds such as isothiocyanates and dithiolthiones found in
broccoli, cauliflower, and cabbage, and beta-carotene found in
carrots have been shown to protect against cancer. Studies have
shown that eating a diet rich in fiber as found in fruits and
vegetables reduces the risk of colon cancer. Exercise and a low fat
diet help control weight and reduce the risk of endometrial, breast,
and colon cancer.
Certain drugs, which are currently being used for
treatment, could also be suitable for prevention. For example, the
drug tamoxifen (Nolvadex), which has been very effective against
breast cancer, is currently being tested by the National Cancer
Institute for its ability to prevent cancer. Similarly, retinoids
derived from vitamin A are being tested for their ability to slow
the progression or prevent head and neck cancers. Certain studies
have suggested that cancer incidence is lower in areas where soil
and foods are rich in the mineral selenium. More trials are needed
to explain these intriguing connections. |