Cancer Study Guide

This essay has a total of 2331 words and 11 pages.



Cancer is a group of diseases characterized by an uncontrolled growth of
abnormal cells. If the spread of these abnormal cells is not controlled, cancer
can cause death. Most cancers take the form of tumors, although not all tumors
are cancers. A tumor is simply a mass of new tissue that serves no
physiological purpose. It can be benign, like a wart, or malignant, like cancer.
Benign tumors are made up of cells similar to the surrounding normal cells and
are enclosed in a membrane that prevents them from penetrating neighboring
tissues. They are dangerous only if their physical presence interferes with
bodily functions. A malignant tumor, or cancer, is capable of invading
surrounding structures, including blood vessels, the lymph system and nerves.
It can also spread to distant sites by the blood and lymphatic circulation and
so can produce invasive tumors in almost any part of the body.
In 1997, an estimated 1,359,150 people in the United States will be
diagnosed with cancer and 554,740 will die of the disease. Early screening for
cancer is believed to be able to drastically reduce the number of deaths due to
the disease. Knowing what to look for when detecting cancer, as well as knowing
if you are in a high risk population are two of the main factors of early
intervention. Early intervention of cancer has proven to increase survival
rates and lower the length and severity of treatments. Detection and protection
are two types of ambulatory care for cancer that begin before the disease is
ever diagnosed.

Cancer often causes symptoms that you can watch for. These include:
change in bowel or bladder habits; a sore that does not heal; unusual bleeding
or discharge; thickening or lump in the breast or any other part of the body;
indigestion or difficulty swallowing; obvious change in a wart or mole; and
nagging cough or hoarseness. These symptoms are not always warning signs of
cancer. They can also be caused by less serious conditions. It is important to
see a doctor if any of these symptoms occur. Only a doctor can make a diagnosis.
A person shouldn't wait to feel pain because early cancer usually does not
cause pain.
Observation is the most widely available examination for the detection
of cancer. It is useful in identifying suspicious lesions in the skin, lip,
mouth, larynx, external genitalia and cervix. The second most available
detection procedure is palpation. It is particularly valuable in detecting
lumps, nodules, or tumors in the breast, mouth, salivary glands, thyroid,
subcutaneous tissues, anus, rectum, prostate, testes, ovaries and uterus and
enlarged lymph nodes in the neck, axilla or groin.
Internal cancers require an extension of observation through endoscopes,
x-rays, magnetic resonance imaging, and ultrasound. Laboratory test, such as
the Pap smear, and occult blood testing of the feces have also proven helpful
for some of the cancers. However, concerns regarding effectiveness and yield
play a particularly important role in decisions to screen for cancers not easily
responsive to earlier detection through physical examination. The performance
of these tests is usually measured in terms of sensitivity, specificity, and
positive and negative predictive values.
The type, periodicity, and commencement of screening in high-risk
populations for most cancers reflect the judgment of expert practitioners rather
that evidence from scientifically- conducted test. Some individuals are known
to be at high risk for cancer, such as those with a strong family history of
cancer. Physician judgment is needed in such circumstances to determine the
most appropriate application of available screening methods. Once the high-risk
person is identified, is counseled appropriately, and regularly undergoes
screening procedures, the benefits of early detection and treatment are
available to this person, yielding a proven higher chance of recovery. Those
people considered high risk should take extra precautions when attempting to
detect cancer.

Important facts that a person should know about how to protect against
getting cancer include: not using tobacco products; eating at least five
servings of fruits and vegetables each day; if you are a woman, getting a
mammogram, pelvic exam and Pap test every year; getting tests done as you get
older for cancers of the colon and rectum; if you are a man, getting early
detection tests for prostate cancer, avoiding too much sunlight by wearing
protective clothing and sun screen; and avoiding unnecessary x-rays. If a
person does have cancer, it is wise to find out what the treatment choices are
and which are best suited for that person. Before getting treatment, it is
advisable to get a second opinion from another doctor. These are all forms of
protection that can be done by an ambulatory basis.

Four basic forms of treatment for cancer are currently practiced. These
are surgery, radiation therapy, biological therapy and chemotherapy. All but
surgery can be performed on an outpatient basis. The physician may use one form
of therapy or a number of different forms in order to produce the desired

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Radiation therapy is one of the major ambulatory treatment modalities
for cancer. Approximately 60% of all people with cancer will be treated with
radiation therapy sometime during the course of their disease. Its
effectiveness as a treatment for cancer was first reported in the late 1800s.
Advances in equipment technology, combined with the science of radiobiology,
have led to today's highly sophisticated treatment centers. Radiation therapy
can now be delivered with maximum therapeutic benefits, minimizing toxicity and
sparing healthy tissues.
Radiation therapy uses high-energy ionizing radiation to kill cancer
cells. It is considered a local therapy because the cancer cells are destroyed
only in the anatomical area being treated. The radiation causes a breakage of
one or both stands of the DNA molecule inside the cells, therefor preventing
their ability to grow and divide. While cells in all phases of the cell cycle
can be damaged by radiation, the lethal effect of radiation may not be apparent
until after one or more cell divisions have occurred. Although normal cells can
also be affected by ionizing radiation, they are usually better able to repair
their DNA damage.
Radiation treatments can be administered externally or internally,
depending on the type and extent of the tumor, however only external radiation
can be administered in an out-patient basis. Some patients have both forms,
one after the other. X-rays, radioactive elements, and radioactive isotopes are
most often used in these forms of treatment.
External radiation treatments are administered by machines that deliver
high-energy radiation. These machines vary according to the amount and type of
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