Prostate Cancer

Definition

Cancer is a disease characterized by the uncontrolled growth, called a tumor, of abnormal cells. Prostate cancer is any type of malignant (cancerous) growth in the prostate.

Description

The prostate is one of the male sex glands, located just below the bladder and in front of the rectum. The prostate is about the size of a walnut and it surrounds part of the urethra (the tube that carries urine from the bladder to the outside of the body). The prostate makes fluid that becomes part of the semen (the fluid that contains sperm).

In the U.S., prostate cancer is the most common cancer and the second leading cause of cancer deaths in men. Statistics show that from 1990 to the present, the number of men diagnosed with prostate cancer has tripled, with an estimated 37,000 expected to die from the disease in 1999.

Causes and Risk Factors

The most common risk factors include:

• being over 55 years of age

• a family history of prostate cancer

• being African-American

Other speculative risk factors include:

• having an enlarged prostate (called benign prostatic hyperplasia, or BPH)

• being exposed to sexually transmitted viral agents

• eating a high saturated fat diet

• exposure to heavy metal and chemicals

• a sedentary lifestyle

• insufficient amounts of vitamin D in the diet

Symptoms

Often, there are no symptoms in the earliest stages of prostate cancer. When symptoms do occur, they may include the following:

• the need to urinate frequently, especially at night

• needing to strain when urinating

• difficulty in starting urination or holding back urine

• the inability to urinate

• a weak or interrupted flow of urine

• painful or burning urination

• blood in the urine

• painful ejaculation

• continuing pain in the lower back, hips or upper thighs

Many of these symptoms are common to non-cancerous prostate conditions, including prostatitis (inflammation of the prostate), prostate stones, infection and BPH. It is important to have any of these symptoms checked by a doctor to find the problem.

Diagnosis

To find the cause of symptoms, the doctor will take a full medical history, a complete physical examination and perform laboratory and diagnostic testing. During the physical exam, the doctor will do a digital rectal exam. The doctor will insert a gloved and lubricated finger into the rectum and feel the prostate to check for hard or lumpy areas. The doctor will also order a blood test, called a prostate-specific antigen (PSA) test.

Prostate-specific antigen is a protein secreted by the prostate. In men with enlargement or infection of the prostate or prostate cancer, the protein leaks into the circulatory system, thereby increasing the level of PSA in the blood.

In order to get an accurate PSA reading: 1) have your blood drawn before the digital rectal exam, 2) don't ejaculate on the day before the blood test, 3) alert your doctor if you are currently taking Proscar for BPH, and 4) if the initial reading indicates a borderline elevation, repeat the test in three or four months.

The readings for having a biopsy are interpreted as follows: men over age 60 with a level higher than 4.0 nanograms per milliliter; men in their 50s with a level of 3.5; and men in their 40s with a level of 2.5.

In order to confirm the diagnosis, the doctor will follow up an elevated PSA or positive digital rectal exam with more definitive testing. Some doctors request a transrectal ultrasonography (TRUS) be performed. In this procedure, sound waves are sent out by a probe inserted into the rectum. The waves bounce off the prostate and a computer uses the echoes to create a picture called a sonogram. TRUS helps the doctor map uneven areas of firmness in the prostate, which assists in the decision to do a biopsy.

There are two types of biopsies performed for the diagnosis of prostate cancer. The first is called a fine needle aspiration (or FNA) - a fine needle is inserted through the rectum or through the space between the scrotum and the anus, to withdraw cells from the suspicious area. The second is called a sextant biopsy - a needle is used to remove six cores of tissue from various sections of the prostate.

Once prostate cancer is diagnosed, other tests, such as computerized tomography, lymph node biopsies and bone scans are used to determine if tumors have spread beyond the prostate.

When prostate cancer is diagnosed, the doctor will determine at what stage (phase or progression) the cancer is. The following staging system is used:

Stage A: Prostate cancer at this stage cannot be felt and causes no symptoms. It is only in the prostate and usually found accidentally when other prostatic surgery is performed.

Stage B:Prostate cancer at this stage is felt during a rectal examination and confirmed during a biopsy because of an elevated PSA level. Cancer is located in the prostate only.

Stage C: Cancer cells have spread outside the prostate to the tissues surrounding the prostate.

Stage D: Cancer cells have spread to lymph nodes or organs and tissues far away from the prostate.

Treatment

If the cancer is located in the prostate gland and considered slow growing, some doctors may recommend a conservative approach of "watchful waiting." During this time, the patient will receive no treatment, but the doctor will closely monitor the size and growth of the tumor and regularly test for elevated PSA levels.

Tumor growth is determined by the Gleason system - the tumor appearance under a microscope distinguishes its grade. The grades of tumors are from 2 to 10. A grade 2 tumor appears as clumped together cancer cells with well defined edges and is less likely to grow rapidly. A higher-grade tumor is dispersed with uneven edges that are apt to spread rapidly. However, after taking into account the tumor stage, the tumor grade, the man's age and the man's overall health, some doctors would recommend other treatment methods.

There are two methods of treatment - local and systemic. Local treatments are used to remove, destroy or control the cancer cells in a specific area. Surgery and radiation therapies are local treatments. Systemic treatments are used to destroy or control cancer cells all over the body. Hormone therapy is a systemic treatment.

Local treatments

Surgery

Radical prostatectomy: the removal of the prostate and some of the tissue around it. There are two types of prostatectomy - perineal prostatectomy, which is done by cutting into the space between the scrotum and the anus and removing the prostate, and retropubic prostatectomy, which is done by cutting into the lower abdomen and removing the prostate. Often before a prostatectomy is performed, the doctor may take out the lymph nodes in the pelvis (a pelvic lymph node dissection) to see if they contain cancer. Radical prostatectomy has become more acceptable with the development of a nerve-sparing technique. The "nerve-sparing" technique is a radical prostatectomy that removes the prostate but leaves one or both of the nerve bundles on either side of the prostate intact so the patient has a chance of potency after surgery. Not everyone qualifies for nerve-sparing surgery, and it should be done only when it seems likely that the cancer does not lie close to the nerve bundles.

TURP: is a procedure in which the cancer is cut from the prostate using a tool with a small wire loop on the end that is placed into the prostate through the urethra. This operation is sometimes done to relieve symptoms caused by the tumor before other treatment, or in men who cannot have a radial prostatectomy because of age or other medical problems.

Radiation therapy

This is the use of high-energy x-rays to kill cancer cells and shrink tumors. There are two types of radiation therapy - external (from a machine) and internal (radioactive materials are implanted) - also called seed implantation therapy. Using a machine called a linear accelerator, radiation is passed through the diseased tissue by means of x-rays.

Seed implantation therapy is the placement of radioisotopes directly into the cancerous prostate, where they emit low-level radiation for about a year. With the help of a transrectal ultrasound and a computerized CT scan, doctors are able to view the precise size and shape of the prostate on a video monitor and nonsurgically guide needles containing the seeds with pinpoint accuracy into the cancerous part of the gland. Two different isotopes are used in prostate implants; Iodine-125 is generally used to treat slow-growing tumors, while palladium-103 is used for faster-growing cancers.

A variant on seed implantation is called high-dose-rate radiation. In this technique, a highly radioactive seed is attached to a wire that is momentarily inserted into the man's prostate through a number of hollow tubes.

Systemic treatments

Hormone therapy is the use of hormones to stop cancer cells from growing. One form of hormone therapy is called an orchiectomy (the surgical procedure for removal of one or both testes). After removing the testicles, the main source of male hormones is gone. Without these hormones, the growth of the prostate cells slows. In another form of hormone therapy, men are given estrogen, a female hormone, or luteinizing hormone-releasing hormone (LHRH), a laboratory made hormone. Both these drugs stop the testicles from producing testosterone.

Staging Treatments

Treatment for men with Stage A cancer depends on whether the cancer cells are found in one or more areas of the prostate. If the cancer cells are found in only one area and the man is older, the doctor may recommend the watchful waiting approach. The doctor may choose this option because the cancer is not causing any symptoms or other problems and the tumor is slow-growing. If younger, the man may have surgery or external radiation therapy.

Men with Stage B cancer are treated with surgery and/or external radiation.

Men with Stage C cancer are treated with surgery and/or external radiation. If the patient is unable to have surgery or radiation therapy, the doctor will recommend palliative treatments (treatments to relieve the symptoms of the disease), and/or radiation, and/or hormone therapy and/or TURP.

Men with Stage D will be treated first with hormone therapy, then external radiation and/or surgery.

Questions to Ask Your Doctor

What tests are going to be done for an accurate diagnosis?

Is the cancer benign or malignant?

Did the cancer originate in the prostate?

Has the cancer spread to any other areas?

What stage of prostate cancer is it?

What type of treatment do you recommend? What are the risks?

If the medication (as in chemotherapy) is prescribed, what are the side effects?

If surgery is recommended, what about post-operative care?

What is the survival rate with or without therapy?

Can diet help decrease the cancer?

What effects will this condition have on sexual activity?