What is Prostate Cancer?
Prostate cancer develops from cells of the prostate gland. Eventually the cancer cells may spread outside the gland to other parts of the body. Most prostate cancers grow very slowly. Autopsy studies show that many elderly men who died of other diseases also had a prostate cancer that neither they nor their doctor were aware of. But some prostate cancers can grow and spread quickly.
The prostate gland is about the size of a walnut and is located in front of the rectum, behind the base of the penis, and under the bladder. It is found only in men, and contains gland cells that produce some of the seminal fluid, which protects and nourishes sperm cells.
The prostate surrounds the upper part of the urethra, the tube that carries urine and semen out of the penis. Nerves located next to the prostate take part in causing an erection of the penis, and treatments that remove or damage these nerves can cause erectile dysfunction, also known as impotence.
Lymph is a clear fluid that contains tissue waste products and immune system cells. Lymphatic vessels carry this fluid to lymph nodes (small, bean-shaped collections of immune system cells important in fighting infections). Most lymphatic vessels of the prostate lead to pelvic lymph nodes. Cancer cells can enter lymph vessels and spread out along these vessels to reach lymph nodes, where they can continue to grow. If prostate cancer cells have multiplied in the pelvic lymph nodes, they are more likely to have spread to other organs of the body as well.
Although several other cell types are found in the prostate, over 99% of prostate cancers develop from glandular cells. The medical term for a cancer that starts in glandular cells is adenocarcinoma. Because other types of prostate cancer are so rare, when someone speaks of prostate cancer it is assumed they are referring to a prostatic adenocarcinoma, unless they specifically mention some other cell type.
Prostatic intraepithelial neoplasia (PIN) is a condition in which there are changes in the microscopic appearance (the size, shape, or the rate at which they multiply) of prostate epithelial cells. Older men are more likely to have this condition. PIN is classified as either low grade or high grade. If a person has high grade PIN, repeat biopsies and PSA tests should be done regularly. PIN may lead to the development of prostate cancer. At this time there is no standard treatment for PIN. Studies are being done to determine if treatments used for BPH (benign prostatic hyperplasia) are also effective in treating PIN.
Source: AMERICAN CANCER SOCIETY
