The Facts About Prostate Cancer
One man in seven will be diagnosed with prostate cancer during his lifetime, making prostate cancer the most common cancer among men in the United States. Almost 181,000 new cases will be diagnosed in the U.S. in 2016, and an estimated 26,120 men will die from the disease.
Those statistics tell only part of the story, however. Thanks to advances in detecting and treating prostate cancer, survival rates have increased steadily in recent years, and most men diagnosed with prostate cancer do not die from the disease. In fact, for every 100 men diagnosed with prostate cancer this year, only about one will die from the disease over the next five years, and only about five will die from the disease over the next 15 years. Of course, the success of treatment for any given patient depends on the nature and extent of his cancer, his overall health, and other factors. Nonetheless, due to the effectiveness of available therapies, the U.S. today is home to more than 2.9 million men who have received a diagnosis of prostate cancer at some point in their lives, often many years or even decades earlier.
The oncology specialists of Regional Cancer Care Associates (RCCA) draw on a wide range of therapies, often combining one type of treatment with another, to individualize each patient’s care. While you should discuss questions and concerns about prostate cancer with your physician or other healthcare provider, RCCA’s specialists provide the information on this page for general educational purposes.
The prostate is a gland located below the bladder and in front of the rectum in males (females do not have a prostate gland). The prostate and the seminal vesicles located immediately behind it produce fluids that are found in semen. The urethra—a tube connected to the bladder that transports urine and semen out of the body via the penis—passes through the middle of the prostate. In younger men, the prostate is about the size of a walnut. The prostate can increase in size in middle-aged and older men, but this does not necessarily indicate that cancer is present. More often, this age-related enlargement is due to a condition called benign prostatic hyperplasia, or BPH.
Definition, Risk Factors, and Symptoms of Prostate Cancer
The development of cancer is a complex biological process involving activity at the molecular level of the body, but for basic purposes, cancer can be defined as uncontrolled cell growth. In prostate cancer, glandular cells almost always are the cells involved in this process, and so most cases of prostate cancer are adenocarcinomas, the medical term for cancers arising from glandular tissue. Other types of prostate cancer, such as transitional cell carcinomas and small cell tumors, are rare. Most prostate cancers develop slowly, although some can grow and spread rapidly.
Increasing age is a risk factor for prostate cancer, with about 60 percent of cases diagnosed in men age 66 and older. A family history of prostate cancer also is a risk factor for the disease; the American Cancer Society reports that men who have a father or brother with prostate cancer are at about twice the risk of the average man. However, most men diagnosed with prostate cancer do not have a family history of the condition. African-American men are at higher risk than non-Hispanic whites, who in turn are at higher risk than Asian-American and Hispanic/Latino men. The possibility of connections between prostate cancer and other potential risk factors, such as dietary habits, exposure to certain chemicals, and sexually transmitted diseases, is unclear and the focus of ongoing research.
There usually are no symptoms of early prostate cancer. As the disease progresses, however, men sometimes experience problems urinating, blood in the urine or semen, erectile dysfunction, and pain in the hips, back or spine. It is important to remember that many of these symptoms, such as a slow or weak urinary stream or difficulty getting an erection, can be caused by many health conditions. Contact your physician promptly about any symptoms you experience.
Detecting and Classifying Prostate Cancer
Screening for prostate cancer includes measuring the level of prostate-specific antigen (PSA) in man’s blood and conducting a digital rectal exam, in which a physician puts a gloved, lubricated finger into the rectum to feel the prostate. If either method yields abnormal findings, further evaluation is conducted. This evaluation involves a detailed medical history and physical examination, and may include obtaining ultrasound images by placing a small probe in the rectum or a prostate biopsy, in which samples of prostate tissue are obtained via a thin needle introduced through the wall of the rectum, typically after administration of a local anesthetic.
If cancerous cells are found on biopsy, a patient’s cancer is assigned a grade through the use of an approach called the Gleason system. In this system, a pathologist examines a sample obtained on biopsy and assigns a grade to the two areas with the greatest presence of cancerous cells. The grading is done on a five-point scale, with one representing tissue that looks very much like normal prostate tissue and five representing very abnormal tissue. The grades for the two areas generally then are added together, resulting in a score ranging from two to ten. The higher the score, the greater the chance that the cancer will grow and spread rapidly. Tests may be ordered to determine whether the cancer has spread beyond the prostate include bone scans, computed tomography (CT) scans, magnetic resonance imaging (MRI), and lymph node biopsy. Not every patient needs every test, and the decision on what type of testing is appropriate for each patient is based on the specifics of his condition.
Once physicians have gathered the necessary information, they assign prostate cancer a stage from I to IV, with various sub-stages in between. The staging generally is based on the so-called TNM system created by the American Joint Committee on Cancer (AJCC). This system considers the extent of the primary tumor, whether the cancer has spread to nearby lymph nodes, whether the cancer has metastasized to other parts of the body, the PSA level at diagnosis, and the Gleason score. Stage I represents localized disease, while Stage IV describes disease that has spread regionally or to distant sites in the body. Five-year survival rates for local and regional stage prostate cancer are significantly higher than for distant stage cancer.
Treating Prostate Cancer
Physicians today have more options than ever before to treat prostate cancer with effective therapies. In many cases, they combine a number of treatment approaches simultaneously or sequentially in a strategy tailored to the specifics of a patient’s disease.
The broad categories of treatment are radiation therapy, cryotherapy, surgery, hormone therapy, chemotherapy, vaccine treatment, and bone-directed treatment. For some patients, active surveillance–also termed watchful waiting–may be appropriate, particularly if the cancer appears to be growing very slowly and a man’s age or health makes him a poor candidate for other approaches.
Radiation therapy options include external beam radiation therapy (EBRT), in which beams of radiation target the cancer from a machine outside the body. EBRT increasingly employs sophisticated, computer-guided techniques such as intensity modulated radiation therapy (IMRT) to precisely map the location of cancerous tissues, delivering higher levels of radiation to those sites while avoiding nearby healthy tissues. Stereotactic body radiation therapy and proton beam radiation therapy also are forms of EBRT. By contrast, brachytherapy is internal radiation therapy and involves placement of tiny radioactive “seeds” or pellets into the prostate. There are several different forms of brachytherapy. In cryotherapy, by contrast, a physician uses ultrasound imaging to guide hollow needles through the skin between the anus and scrotum to the prostate to deliver very cold gas to freeze and destroy the prostate and its cancerous cells.
Surgical treatment of prostate cancer includes operations that involve an “open approach,” in which a long incision is made in the skin and, more commonly in recent years, procedures performed with a laparoscope and related instruments. In terms of open approaches, a radical retropubic prostatectomy removes the prostate and nearby tissues through an incision in the abdomen. In radical perineal prostatectomy, the incision is made in the skin between the anus and scrotum. In laparoscopic radical prostatectomy, the surgeon inserts long, thin instruments through several small incisions in the skin to reach and remove the prostate under video guidance. In some cases, a robotic system is used to increase the precision of the laparoscopic procedure.
Hormone therapy typically entails giving medications that suppress the production or interfere with the action of androgens, male sex hormones such as testosterone that can stimulate the growth of prostate cancer cells.
Chemotherapy may be employed if cancer has spread outside the prostate gland. Several different chemo drugs have been shown to slow the growth of cancer and reduce symptoms. Unlike vaccines administered to prevent infectious diseases, a vaccine used in prostate cancer combats existing disease by boosting the body’s immune system so that it can attack prostate cancer cells. Bone-directed treatments can have many purposes, including relieving the pain caused by prostate cancer cells that have metastasized to bone, slowing the growth of cancer in the bone, and strengthening bone. They include drugs that affect bone metabolism, steroids, and radiopharmaceutical agents that kill cancer cells in the bone by emitting radiation in the immediate area of those cancerous cells.
Each treatment option may offer benefits to appropriately selected patients, and each has potential side effects that need to be considered, watched for, and addressed if they occur. The wide variety of therapies available gives physicians a greater ability than ever before to tailor treatment to each man’s particular situation, but it also introduces a degree of complexity that calls for in-depth discussion between the patient and the physicians treating him.
Beyond these currently employed approaches, several new therapies and treatment strategies are being developed for prostate cancer, and men may want to consider participating in a clinical trial of one of those approaches, particularly if they have not responded well to current treatments.
In summary, prostate cancer remains a major health concern, one that takes a high toll on American men. However, advances in diagnosis and treatment offer more hope than ever before for effectively treating patients.
The oncologists of Regional Cancer Care Associates are always available to see you or to consult with your physician if you have been diagnosed with prostate cancer. In addition, reliable resources for obtaining further information include the: