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UNDERSTANDING CANCER
Understanding Cancer ancer begins in cells, the building blocks that
make up tissues. Tissues make up the organs of the body.
Normally, cells grow and divide to form new cells as the body needs
them. When cells grow old, they die,
and new cells take their place. Sometimes, this orderly process goes
wrong. New cells form when the body does not need them, and old cells
do not die when they should. These extra cells can form a mass of
tissue called a growth or tumor.
Tumors can be benign or malignant:
a Benign tumors are not cancer:
—Benign tumors are rarely life-threatening.
—Generally, benign tumors can be removed. Theyusually do not grow back.
—Cells from benign tumors do not invade thetissues around them.
—Cells from benign tumors do not spread to otherparts of the body.
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Benign prostatic hyperplasia (BPH) is the
abnormal growth of benign prostate cells. The prostate
grows larger and squeezes the urethra. This prevents the
normal flow of urine. BPH is a very common problem. In the
United States, most men over the age of 50 have
symptoms of BPH. For some men, symptoms may be severe
enough to need treatment. To learn about BPH and other
prostate changes that are not cancer, read NCI's booklet
Understanding Prostate Changes: A Health Guide for Men. |
a Malignant tumors are cancer:
—Malignant tumors are generally more serious thanbenign tumors. They
may be life-threatening.
—Malignant tumors often can be removed. Butsometimes they grow back.
—Cells from malignant tumors can invade anddamage nearby tissues and
organs.
—Cells from malignant tumors can spread(metastasize) to other parts of
the body. Cancercells spread by breaking away from the original (primary)
tumor and entering the bloodstream or lymphatic system. The cells
invade other organs and form new tumors that damage these organs. The
spread of cancer is called metastasis.
When prostate cancer spreads, cancer is often found in
nearby lymph nodes. If cancer has reached these nodes, it also
may have spread to other lymph nodes, the bones, or other organs.
When cancer spreads from its original place to another part of
the body, the new tumor has the same kind of abnormal cells and
the same name as the primary tumor. For example, if prostate
cancer spreads to bones, the cancer cells in the bones are
actually prostate cancer cells. The disease is metastatic
prostate cancer, not bone cancer. For that reason, it is treated
as prostate cancer, not bone cancer. Doctors call the new tumor
"distant" or metastatic disease.
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