Physicians set record straight on prostate-specific antigen testing
SPRINGFIELD – First it was their recommendation on breast cancer screening, now it is the U.S. Preventive Services Task Force's (USPSTF) recommendation in May on screening for prostate cancer – the second leading cause of cancer death in American men behind only lung cancer – that has caused a controversy among clinicians and confusion among men.
The USPSTF recommends against prostate-specific antigen (PSA) testing for healthy men, regardless of age, but does not include the use of the PSA test for surveillance after diagnosis or treatment of prostate cancer.
"All men deserve to know what the science tells us about PSA screening – that there is a very small potential benefit and significant potential harms," Dr. Michael LeFevre, co-chair of the USPSTF, said.
Now is the time, during National Prostate Cancer Awareness Month, to set the record straight for those men who might be uncertain about what to do when it comes to testing for prostate cancer, which is 100 percent treatable if caught in its earliest stages.
According to Dr. Stephen Gallo, a member of the medical staff at Baystate Medical Center, the USPSTF looks at the balance of benefits and harms of prostate cancer screening.
"Patients should be made aware of this balance. Our present goal is to identify patients with lethal disease where we can offer potentially lifesaving treatment. However, we don't want to overdiagnose or overtreat patients. Many patients have clinically insignificant disease and do not need to be treated or should be monitored with what we refer to as 'active surveillance,'" Gallo of Pioneer Valley Urology, P.C., said
"The difficulty that physicians will have is to explain this dilemma to their patients, so that they can make an informed decision about whether or not to undergo PSA testing," he added.
Current screening guidelines issued by the American Urological Association (AUA) recommend that men starting at age 40 get both a digital rectal exam and a PSA test. A PSA test is a blood test which measures prostate-specific antigen (PSA), a substance made by normal prostate cells. The higher the PSA levels, the more likely the chance of prostate cancer. To predict how likely the cancer is to cause symptoms, doctors consider a man's PSA level, his physical exam findings, the appearance of his cancer under the microscope, and his age. Doctors recommend that men get this initial testing at age 40, so that they can use these initial results as a baseline.
While the exact causes of prostate cancer are not known, research indicates that men with certain risk factors – including age, race (especially African Americans), a diet high in red meat and fat, and family history – are more likely than others to develop prostate cancer.
Many men diagnosed with prostate cancer have no symptoms and only learn about having the disease through screening. However, symptoms that could indicate possible prostate cancer include the urgent need to urinate, hesitancy or slow stream when urinating, and pain or blood during urination.
Today, men have many treatment options for their prostate cancer, including active surveillance (also referred to as watchful waiting), radiation involving the implantation of radioactive "seeds," or external beam therapy using intensity modulated radiation therapy (IMRT), chemotherapy, hormone treatment, and surgery to remove all or part of the prostate gland.
"In many situations, especially for patients with high risk prostate cancer, surgery in combination with hormones and radiation has become the norm for prostate cancer treatment and offers the best chance of local control of the cancer and potential cure," Dr. Michael Yunes, radiation oncologist, Baystate Regional Cancer Program, said. The term "local control" used by doctors refers to the arrest of cancer growth at the site of origin.
Yunes noted that advances in technology have made it possible to target radiation to the prostate more precisely than in the past, thanks to new methods such as IMRT that increase the effectiveness of radiation therapy and minimize any side effects.
"As part of intensity modulated radiation therapy, three non-radioactive gold seeds are planted as markers in the prostate by a urologist working alongside the radiation oncologist as partners in the patient's care. Because the prostate moves inside the body from day to day, these marker seeds allow for better external localization of the prostate, thereby increasing the accuracy of the radiation," Yunes said.
However, both Yunes and Gallo said any treatment selection, in close consultation with a patient's physician, will depend on age and general health, current symptoms, grade of tumor, number of biopsy tissue samples that contain cancer cells, and the stage of the cancer. In some cases, especially in older patients, the progression of the disease may be so slow that the risk of complications from treatment may outweigh the benefits of the treatment. Complications include a higher risk of incontinence and erectile dysfunction with surgery, while there is an increased risk of gastrointestinal issues, diarrhea, and frequency of urination with radiation.
For those requiring surgery, a rapidly growing choice for prostate cancer treatment is minimally invasive surgery using the da Vinci Surgical System, first pioneered in the region by Dr. Gallo at Baystate Medical Center. The highly-advanced robotic equipment requires a minimal incision and can result in a better nerve-ending sparing operation, mitigating some of the potential side effects of incontinence and sexual dysfunction which can accompany the removal of the prostate gland. But research shows those side effects are temporary in many patients.
"Still, for many more prostate cancer patients today, they are delaying treatment and choosing 'active surveillance,'" said Dr. Gallo.
The National Cancer Institute defines active surveillance as closely watching a patient's prostate cancer, but not giving treatment unless there are changes in test results. Active surveillance avoids problems that may be caused by treatment such as radiation or surgery. It is used to find early signs that the cancer is getting worse and may have metastasized. During active surveillance, patients are given certain exams and tests on a regular schedule.
"Treatment can be started at a later date if the cancer volume increases or the tumor is later found to be more aggressive during the monitoring period," Gallo said.
Gallo said a study, published online on April 4, 2011 in the Journal of Clinical Oncology, noted that results of the largest and longest study of its kind involving men diagnosed with what is referred to as very-low-risk prostate cancer, provided strong evidence that active surveillance is the "preferred option" for most men with very-low-risk prostate disease.
"Watchful waiting can also be an option for those men with very slow growing cancers that are confined to a small area of the prostate, as well as for some men with other serious medical conditions that might make surgery or other treatments risky to their health," Gallo said.
"In general, patients who are on observation usually have a shorter life expectancy because of their age or medical condition," he added.
For more information on the Baystate Regional Cancer Program, visit baystatehealth.com/brcp
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