Prostate Cancer: Symptoms, Tests, and Treatment
Risk factors for prostate cancer include family history, age and race; but new approaches to treatment hold promise.
Prostate cancer is the most common cancer among men and the second most common cause of cancer-related deaths among American men. African-American men are more likely to get prostate cancer and twice as likely to die from the disease.
The U.S. Food and Drug Administration (FDA) regulates screening tests and treatments for prostate cancer to ensure their safety and effectiveness.
The prostate is part of the male reproductive system that makes semen. The walnut-sized gland is located beneath the bladder and surrounds the upper part of the urethra, the tube that carries urine from the bladder.
Signs and Symptoms
Prostate cancer is frequently a very slow growing disease, often causing no symptoms until it is in an advanced stage. At that point, symptoms may include difficulty starting urination, weak or interrupted flow of urine, and frequent urination, especially at night.
However, these symptoms can have many other causes than prostate cancer, such as a benign enlarged prostate. If you have any concerns about any of these symptoms, you should contact your health care professional. Most men with prostate cancer die of other causes, and many never know that they have the disease. But once prostate cancer begins to grow quickly or spreads outside the prostate, it is dangerous. While the disease is rare before age 50, experts believe that most elderly men have traces of it.
In 2004, FDA approved docetaxel, the first chemotherapy for metastatic prostate cancer that showed a survival benefit, after years of research failed to find a treatment that would prolong the lives of metastatic prostate cancer patients. Metastatic is a term used to describe a cancer that spreads from the original location to other areas of the body.
“When prostate cancer metastasizes to another location in the body, it is in most cases incurable and the goal of treatment is to improve a patient’s symptoms or function, or to extend the length of the patient’s life, ” says Daniel Suzman, M.D., a medical officer in FDA’s Office of Hematology and Oncology Products in the Center for Drug Evaluation and Research. Since docetaxel, FDA has approved five additional therapies, all of which have shown improvements in survival.
In addition, several major trials showed that adding either docetaxel or abiraterone acetate, a potent form of hormone therapy, to standard hormonal therapy for men with metastatic disease that had not previously been treated improved their survival.
According to Suzman, that approach has become a standard of care for men who have a high burden of disease (such as cancer that has spread to the soft tissues or to many spots in the bone). To receive docetaxel, men must be fit for chemotherapy. Docetaxel can cause serious side effects that may lead to death such as low white blood cell counts (neutropenia), and serious allergic reactions. Common side effects include low blood cell counts, infection, nosebleeds, decrease appetite, weight gain, rash, hair loss, and nerve pain. Abiraterone acetate can cause elevated levels of hormones that cause fluid retention, high blood pressure, and low potassium and must be taken with a steroid, prednisone, to prevent this. Other important side effects include liver toxicity, inability of the adrenal glands to produce enough stress hormones, as well as fatigue, joint pain, nausea, hot flush, diarrhea, vomiting, upper respiratory infection, cough, and headache. Abiraterone acetate tablets are also approved, in combination with prednisone, for patients with metastatic high-risk, castration-sensitive prostate cancer.
Some men who are treated with hormone therapy before they experience metastatic disease may develop a form of prostate cancer that is resistant to standard hormone therapy (known as non-metastatic castration-resistant prostate cancer). The FDA recently approved apalutamide, a drug that blocks the effect of testosterone and similar hormones on the prostate cancer cells, for men with this form of the disease based on its ability to delay the time until men developed metastatic disease. Serious side effects of apalutamide include falls/fractures and seizure. Other common side effects include fatigue, high blood pressure, rash, diarrhea, nausea, weight loss, joint pain, hot flush, decreased appetite, and swelling.
Screening and Tests
Risk of prostate cancer can be measured through prostate-specific antigen (PSA) testing. PSA is a protein produced by cells of the prostate gland. Because of the widespread use of PSA testing in the United States, prostate cancer is often detected early. In some cases, the prostate cancer found can be very slow growing.
In most of these cases, the prostate cancer may not require treatment, and the use of PSA testing to screen for prostate cancer is controversial, Suzman says. Side effects from treatment of prostate cancer with surgery or radiation therapy can include urinary incontinence, erectile dysfunction, and bowel problems.
One promising area of prostate cancer research is related to preventing overtreatment of patients with prostate cancer that is still localized to the prostate and who have a low risk of becoming symptomatic or dying from the condition. Careful selection of these men to ensure that they are low-risk is crucial. There is increasing evidence that close surveillance and repeated biopsies may safely allow these patients to delay definitive therapy (surgery or radiation). “There is a need to reduce the burden to patients of overtreatment if the prostate cancer is slow growing,” Suzman says.