Armune BioScience

Prostate cancer occurs when cells within the prostate grow uncontrollably, creating small tumors. The term "cancer" refers to a condition in which the regulation of cell growth is lost and cells grow uncontrollably. Most cells in the body are constantly dividing, maturing and then dying in a tightly controlled process. Unlike normal cells, the growth of cancer cells is no longer well-regulated. Instead of dying as they should, cancer cells outlive normal cells and continue to form new, abnormal cells.

Abnormal cell growths are called tumors. The term "primary tumor" refers to the original tumor; secondary tumors are caused when the original cancer spreads to other locations in the body. Prostate cancer typically is comprised of multiple very small, primary tumors within the prostate. At this stage, the disease is often curable (rates of 90% or better) with standard interventions such as surgery or radiation that aim to remove or kill all cancerous cells in the prostate. Unfortunately, at this stage the cancer produces few or no symptoms and can be difficult to detect.

If untreated and allowed to grow, the cells from these tumors can spread in a process called metastasis. In this process, prostate cancer cells are transported through the lymphatic system and the bloodstream to other parts of the body, where they lodge and grow secondary tumors. Once the cancer has spread beyond the prostate, cure rates drop dramatically.

In most cases, prostate cancer is a relatively slow-growing cancer, which means that it typically takes a number of years for the disease to become large enough to be detectable, and even longer to spread beyond the prostate. However, a small percentage of patients experience more rapidly growing, aggressive forms of prostate cancer. Unfortunately, it is difficult to know for sure which prostate cancers will grow slowly and which will grow aggressively – complicating treatment decisions.

When prostate cancer spreads to another site, such as bone, the new tumor is still considered to be prostate cancer, not bone cancer.

The Prostate Cancer Foundation (PCF) reports that prostate cancer is the most common non-skin cancer in America, affecting 1 in 6 men. A non-smoking man is more likely to develop prostate cancer than he is to develop colon, bladder, melanoma, lymphoma and kidney cancers combined. In fact, a man is 35% more likely to be diagnosed with prostate cancer than a woman is to be diagnosed with breast cancer.

According to the American Cancer Society (ACS), in 2010, more than 217,000 men were diagnosed with prostate cancer, and more than 32,000 men died from the disease. About 1 man in 36 will die of prostate cancer. One new case occurs every 2.7 minutes and a man dies from prostate cancer every 19 minutes.

The older you are, the more likely you are to be diagnosed with prostate cancer. Although only 1 in 10,000 under age 40 will be diagnosed, the rate shoots up to 1 in 38 for ages 40 to 59, and 1 in 15 for ages 60 to 69. In fact, more than 65% of all prostate cancers are diagnosed in men over the age of 65.

It is estimated that there are more than 2 million American men currently living with prostate cancer.

According to the PCF, African American men are 61% more likely to develop prostate cancer compared with Caucasian men and are nearly 2.5 times as likely to die from the disease. Men with a single first-degree relative—father, brother or son—with a history of prostate cancer are twice as likely to develop the disease, while those with two or more relatives are nearly four times as likely to be diagnosed. The risk is even higher if the affected family members were diagnosed at a young age, with the highest risk seen in men whose family members were diagnosed before age 60.

Although genetics might play a role in deciding why one man might be at higher risk than another, social and environmental factors, particularly diet and lifestyle, likely have an effect as well.

When weighing risk factors for prostate cancer, it's also important to recognize that there are non-risk factors, or factors that have not been linked to an increase in risk. The most common misperception about the risk of prostate cancer is that the presence of non-cancerous conditions of the prostate increases the risk of prostate cancer. Although these conditions can cause symptoms similar to those of prostate cancer and should be evaluated by a physician, there is no evidence that having BPH (benign prostatic hyperplasia) or prostatitis increases the risk for developing prostate cancer.

BPH is a non-cancerous enlargement of the prostate. Because the urethra, the tube that carries urine from the bladder out of the body, runs directly through the prostate, enlargement of the prostate in BPH squeezes the urethra, making it difficult, and often painful, for men to urinate.

The growth of the prostate in men with BPH is unrelated to prostate cancer, and a number of research studies have shown that the presence of BPH does not make a man any more or less likely to develop prostate cancer.

Prostatitis is an infection in the prostate, and is the most common cause of urinary tract infection in men. Most treatment strategies are designed to relieve the symptoms of prostatitis, which include fever, chills, burning during urination, or difficulty urinating. Research has shown that the presence of prostatitis does not make a man any more or less likely to develop prostate cancer.

According to ACS, early prostate cancer usually has no symptoms. With more advanced disease, individuals may experience weak or interrupted urine flow; inability to urinate or difficulty starting or stopping the urine flow; the need to urinate frequently, especially at night; blood in the urine; or pain or burning with urination. Advanced prostate cancer commonly spreads to the bones, which can cause pain in the hips, spine, ribs, or other areas. Many of these symptoms are more likely to be caused by conditions other than prostate cancer, however.

Screening for prostate cancer can be performed in a physician's office using two tests: the PSA (prostate-specific antigen) blood test, and the digital rectal exam (DRE). Although the DRE and PSA tests cannot diagnose prostate cancer, they can signal the need for a biopsy to examine the prostate cells and determine whether they are cancerous. In some men, changes in urinary or sexual function lead to a full evaluation by the doctor, and, if prostate cancer is suspected, a biopsy will be performed.

A biopsy is a procedure in which a sample of body tissue is removed and then looked at under a microscope. A core needle biopsy is the main method used to diagnose prostate cancer. It is usually done by an urologist, a surgeon who treats cancers of the genital and urinary tract, which includes the prostate gland. Using transrectal ultrasound the doctor quickly inserts a needle through the wall of the rectum into the prostate gland. When the needle is pulled out it removes a small cylinder (core) of tissue, usually about 1/2-inch long and 1/16-inch across. This is repeated from 8 to18 times, but most urologists will take about 12 samples. These are sent to the lab to see if cancer is present. The biopsy procedure may cause some discomfort or pain, but the procedure is short, and can usually be performed without an overnight hospital stay.

Under normal conditions, prostate cells, just like all other cells in the body, are constantly reproducing and dying, and each new prostate cell has the same shape and appearance as all of the other prostate cells. But cancer cells look different, and the degree to which they look different from normal cells is what determines the cancer grade. "Low-grade" tumor cells tend to look very similar to normal cells, whereas "high-grade" tumor cells have mutated so much that they often barely resemble the normal cells.

The Gleason grading system accounts for the five distinct patterns that prostate tumor cells tend to go through as they change from normal cells. The scale runs from 1 to 5, where 1 represents cells that are very nearly normal, and 5 represents cells that don't look much like prostate cells at all.

After examining the cells under a microscope, the pathologist looking at the biopsy sample assigns one Gleason grade to the most common pattern, and a second Gleason grade to the next most common pattern. The two grades are added, and the Gleason score, or sum, is determined.

Generally speaking, the Gleason score tends to predict the aggressiveness of the disease and how it will behave. The higher the Gleason score, the less the cells behave like normal cells, and the more aggressive the tumor tends to be.

Staging determines the extent of prostate cancer. Localized prostate cancer means that the cancer is confined within the prostate. Locally advanced prostate cancer means that most of the cancer is confined within the prostate, but some has started to escape to the immediate surrounding tissues. In metastatic disease, the prostate cancer is growing outside the prostate and its immediate environs, possibly to more distant organs.

While there are several different staging systems for prostate cancer, the most widely used system is the American Joint Committee on Cancer (AJCC) TNM System.

The TNM System describes:

1. the extent of the primary tumor (T category)
2. whether the cancer has spread to nearby lymph nodes (N category)
3. the absence or presence of distant metastasis (M category)

The overall stage takes all 3 categories into account, along with the Gleason score described above.

There are actually 2 types of staging for prostate cancer. The clinical stage is your doctor's best estimate of the extent of your disease, based on the results of the physical exam (including DRE), lab tests, prostate biopsy, and any imaging studies you have had.

If you have surgery, your doctors can also determine the pathologic stage, which is based on the surgery and examination of the removed tissue. This means that if you have surgery, the stage of your cancer might actually change afterward (if cancer was found in a place it wasn't suspected, for example). Pathologic staging is likely to be more accurate than clinical staging, as it allows your doctor to get a firsthand impression of the extent of your disease. This is one possible advantage of having surgery (radical prostatectomy) as opposed to radiation therapy or watchful waiting (expectant management).

Both types of staging use the same categories (but the T1 category is not used in pathologic staging).

T categories

There are 4 categories for describing the local extent of the prostate tumor, ranging from T1 to T4. Most of these have subcategories as well.

T1: Your doctor can't feel the tumor or see it with imaging such as transrectal ultrasound.

T1a: The cancer is found incidentally (by accident) during a transurethral resection of the prostate (often abbreviated as TURP) that was done for benign prostatic hyperplasia (BPH). Cancer is present in less than 5% of the tissue removed.
T1b: The cancer is found during a TURP but is present in more than 5% of the tissue removed.
T1c: The cancer is found by needle biopsy that was done because of an increased PSA.

T2: Your doctor can feel the cancer when a digital rectal exam (DRE) is done, but it still appears to be confined to the prostate gland.

T2a: The cancer is in one half or less of only one side (left or right) of your prostate.
T2b: The cancer is in more than half of only one side (left or right) of your prostate.
T2c: The cancer is in both sides of your prostate.

T3: The cancer has begun to grow and spread outside your prostate and may involve the seminal vesicles.

T3a: The cancer extends outside the prostate but not to the seminal vesicles.
T3b: The cancer has spread to the seminal vesicles.

T4: The cancer has grown into tissues next to your prostate (other than the seminal vesicles), such as the bladder sphincter (muscle that helps control urination), the rectum, and/or the wall of the pelvis.

N categories

N0: The cancer has not spread to any lymph nodes.

N1: The cancer has spread to one or more regional (nearby) lymph nodes in the pelvis.

M categories

M0: The cancer has not spread beyond the regional lymph nodes.

M1: The cancer has spread beyond the regional nodes.

M1a: The cancer has spread to distant (outside of the pelvis) lymph nodes.
M1b: The cancer has spread to the bones.
M1c: The cancer has spread to other organs such as lungs, liver, or brain (with or without bone disease).

Once the T, N, and M categories have been determined, this information is combined, along with the Gleason score, in a process called stage grouping. The overall stage is expressed in Roman numerals from I (the least advanced) to IV (the most advanced). This is done to help determine treatment options and the outlook for survival or cure.

Stage I: T1a, N0, M0, low Gleason score (2 to 4)
The cancer is still within the prostate and has not spread to lymph nodes or elsewhere in the body. The cancer was found during a transurethral resection, it had a low Gleason score (2 to 4), and less than 5% of the tissue was cancerous.

Stage II: T1a, N0, M0, Gleason score of 5 to 10; OR T1b-T2, N0, M0, any Gleason score
The cancer is still within the prostate and has not spread to the lymph nodes or elsewhere in the body, and one of the following applies:

It was found during a transurethral resection, was less than 5% of the tissue removed [T1a], and has an intermediate or high Gleason score (5 or higher),
It was found during a transurethral resection and more than 5% of the tissue contained cancer [T1b]; or
It was discovered because of a high PSA level, cannot be felt on digital rectal exam or seen on transrectal ultrasound, and was diagnosed by needle biopsy [T1c]; or
It can be felt on digital rectal exam or seen on transrectal ultrasound [T2].

Stage III: T3, N0, M0, any Gleason score (2 to 10)
The cancer has begun to spread outside the prostate and may have spread to the seminal vesicles, but it has not spread to the lymph nodes or elsewhere in the body.

Stage IV: T4, N0, M0; OR
any T, N1, M0; OR
any T, any N, M1 (any Gleason score)
One or more of the following apply:

The cancer has spread to tissues next to the prostate (other than the seminal vesicles), such as the bladder's external sphincter (muscle that helps control urination), rectum, and/or the wall of the pelvis (T4); and/or
It has spread to the lymph nodes (N1); and/or
It has spread to other, more distant sites in the body (M1).

Knowing the stage of disease can help to determine how aggressively the disease needs to be treated, and how likely it is to be eradicated by the available treatment options.

Treatment options vary depending on age, stage and grade of the cancer, and other medical conditions, and should be discussed with the individual's physician. The grade assigned to the tumor, typically called the Gleason score, indicates the aggressiveness of the cancer and ranges from 2 (nonaggressive) to 10 (very aggressive).

Surgery, external beam radiation, or radioactive seed implants (brachytherapy) may be used to treat early stage disease; hormonal therapy may be added in some cases. Careful observation ("active surveillance") rather than immediate treatment may be appropriate for some men with less aggressive tumors, especially men who are older or who have other health problems.

Hormonal therapy, chemotherapy, radiation, or a combination of these treatments is used to treat more advanced disease.

According to the American Cancer Society, more than 90% of all prostate cancers are discovered in the local and regional stages; the 5-year relative survival rate for patients whose tumors are diagnosed at these stages approaches 100%. According to the most recent data, relative 10-year survival is 93% and 15-year survival is 79%.