PROSTATE CANCER DEFINED
Cancer that forms in tissues of the prostate
(a male gland in the reproductive system found
below the bladder in front of the rectum).
WHAT IS PROSTATE CANCER?
Prostate Cancer is a malignant (cancerous) tumor (growth) that consists of cells from the prostate gland. Generally, the tumor usually grows slowly and remains confined to the gland for many years. During this time, the tumor produces little or no symptoms or outward signs (abnormalities on physical examination). However, all Prostate Cancers do not behave similarly. Some aggressive types of Prostate Cancer grow and spread more rapidly than others and can cause a significant shortening of life expectancy in men affected by them. A measure of Prostate Cancer aggressiveness is the Gleason score, which is calculated by a trained pathologist observing prostate biopsy specimens under the microscope.
As the cancer advances, however, it can spread beyond the prostate into the surrounding tissues (local spread). Moreover, the cancer also can metastasize (spread even farther) throughout other areas of the body, such as the bones, lungs, and liver. Symptoms and signs, therefore, are more often associated with advanced Prostate Cancer.
WHY IS PROSTATE CANCER IMPORTANT?
Prostate Cancer is the most common malignancy in American men and the second most leading cause of deaths from cancer, after lung cancer. According to the American Cancer Society’s most recent estimates, approximately 238,590 new cases of Prostate Cancer would be diagnosed in 2013 and approximately 29,720 would die from the disease.
The estimated lifetime risk of being diagnosed with the disease is one in six men. The lifetime risk of death from Prostate Cancer is one in 36 men. It is estimated that two men are diagnosed with Prostate Cancer every five minutes. As reflected in these numbers, Prostate Cancer is likely to impact the lives of a significant percentage of men that are alive today.
Over the years, however, the death rate from this disease has shown a steady decline, and currently, more than 2 million men in the United States are still alive after being diagnosed with Prostate Cancer at some point in their lives.
Although it is subject to controversy, many experts in this field, therefore, recommend that all men should undergo screening for Prostate Cancer beginning at age 40. Screening recommendations can be confusing, as they refer to testing being done on large groups of people. Each patient’s case should be considered on its own merits. Certainly, a rectal examination for men is indicated beginning at age 40 and should include palpitation of the back of the prostate gland during such an examination. African American men have a higher incidence of Prostate Cancer, and further screening may be considered appropriate for them. Men with a family history of Prostate Cancer are also at an increased risk and should be considered for earlier evaluation than others.
WHAT ARE THE CAUSES OF PROSTATE CANCER?
The cause of Prostate Cancer is unknown, but the cancer is not thought to be related to benign prostatic hyperplasia (BPH). The risk (predisposing) factors for Prostate Cancer include advancing age, genetics (heredity), hormonal influences, and such environmental factors as toxins, chemicals, and industrial products. The chance of developing Prostate Cancer increases with age. Thus, Prostate Cancer under age 40 is extremely rare, while it is common in men older than 65 years of age. As a matter of fact, some studies have suggested that among men over 65 years of age, two-thirds, or 67%, of them may have Prostate Cancer cells present in the prostate gland. More than 67% of Prostate Cancers are diagnosed in men older than 65 years of age.
There are differences in diagnoses and death rates among different racial groups. These differences in diagnoses and death rates are, however, more likely to reflect a difference in factors such as environmental exposure, diet, lifestyle, and health-seeking behavior rather than any racial susceptibility to Prostate Cancer. Recent studies indicate that this disparity is progressively decreasing, with chances of complete cure in men undergoing treatment for organ-confined Prostate Cancer (cancer that is limited to within the prostate without spread outside the confines of the prostate gland) - irrespective of race.
Genetics (heredity), as just mentioned, plays a role in the risk of developing Prostate Cancer. Prostate Cancer is more common among family members of individuals with Prostate Cancer.
Testosterone, the male hormone produced by the testicles, directly stimulates the growth of both normal prostate tissue and Prostate Cancer cells. Therefore, this hormone is thought to be involved in the development and growth of Prostate Cancer. The important implication of the role of this hormone is that decreasing the level of testosterone should be (and usually is) effective in inhibiting the growth of the Prostate Cancer.
The role of environment, nationality, diet, smoking, and obesity as risk factors for Prostate Cancer are being explored, but links have not been proven.
WHAT ARE THE SYMPTOMS AND SIGNS OF PROSTATE CANCER?
In the early stages, Prostate Cancer often causes no symptoms for many years. As a matter of fact, these cancers frequently are first detected by an abnormality on a blood test (the PSA, discussed below) or as a hard nodule (lump) in the prostate gland. Occasionally, the doctor may first feel a hard nodule during a routine digital (done with the finger) rectal examination. The prostate gland is located immediately in front of the rectum.
Rarely, in more advanced cases, the cancer may enlarge and press on the urethra. As a result, the flow of urine diminishes and urination becomes more difficult. Patients may also experience burning with urination or blood in the urine. As the tumor continues to grow, it can completely block the flow of urine, resulting in a painfully obstructed and enlarged urinary bladder. These symptoms by themselves, however, do not confirm the presence of Prostate Cancer. Most of these symptoms can occur in men with non-cancerous (benign) enlargement of the prostate (the most common form of prostate enlargement). However, the occurrence of these symptoms should prompt an evaluation by the doctor to rule out cancer and provide appropriate treatment.
Furthermore, in the later stages, Prostate Cancer can spread locally into the surrounding tissue or the nearby lymph nodes, called pelvic nodes. The cancer then can spread even further (metastasize) to other areas of the body. Symptoms of metastatic disease include fatigue, bone pain, malaise, and weight loss. During a rectal examination, the doctor can sometimes detect local spread into the surrounding tissues. That is, the physician can feel a hard, fixed (not movable) tumor extending from and beyond the gland. Prostate Cancer usually metastasizes first to the lower spine or the pelvic bones (the bone connecting to the lower spine to the hips), thereby causing back or pelvic pain.
DID YOU KNOW?
(JUST THE FACTS ABOUT PROSTATE CANCER)
Prostate Cancer is the second leading cause of deaths from cancer among men in the United States.
It is estimated 161,360 new cases of Prostate Cancer will be diagnosed in 2017 in the United States.
It is estimated that 26,730 of those new cases will die.
One in six men in the United States will be diagnosed with Prostate Cancer in their lifetime.
Men should have a PSA (Prostate Specific Antigen) test and digital rectal examination by age 40, with follow-up screening by age 45.
Men having a greater chance of getting Prostate Cancer at age 50 years or older are African-Americans and other minority males whose father, brother or son have had Prostate Cancer.
Currently there are no specific measures known for the prevention of Prostate Cancer. However, early screening with PSA and digital rectal examinations could lead to diagnoses of Prostate Cancer.