If you had prostate cancer, would you want to know? Consider this: prostate cancer grows slowly, and in many cases, undetected tumors never become life threatening. Screening allows clinicians to diagnose and treat tumors at their earliest stages, when they are still asymptomatic. Treatments for prostate cancer are associated with debilitating side affects, including sexual impotence, incontinence, infection, or diarrhea. This means, according to recent interim data from two studies, many men are undergoing prostate cancer treatments that confer a lot of risk but no life-saving benefit.
Studies Agree Screening Leads to Unnecessary Treatment
One study, conducted in the United States, included nearly 77,000 men aged 55 to 74 years. Half of the men underwent routine prostate cancer screening, and the other half received screening only if they developed signs or symptoms that warranted it. Men in the screened group were 22% more likely to get a diagnosis of prostate cancer, and many received treatment. Researchers followed men in both groups for 7 to 10 years, during which time, 50 in the “screened” group died from prostate cancer compared with 44 in the standard-care group.
The second study compiled data from seven European trials that cumulatively enrolled 162,243 men, aged 55 to 69 years. Median follow-up was 9 years, and men who received regular screening were 20% less likely to die from prostate cancer than those who did not undergo screening. While these results conflict with those of the US study, which found no benefit to screening, they still indicate that 48 men would have to undergo treatment to prevent one prostate cancer death. This suggests that 47 men received unnecessary treatment. Both studies are ongoing, and investigators expect to update the results in the coming years.
Is Watching and Waiting a Safe Approach?
Another study, published in the March 19 issue of Urology, found that it is safe for men with “low risk” prostate cancer to forego treatment and adopt a watchful waiting approach. In the multi-center study, which took place from 1991-2007, 262 American and Canadian men with T1-T2a prostate cancer had no treatment for their initial tumors after a staging biopsy. Every 6 months, they visited their physician, who conducted a physical examination to look for progression and evaluated their PSA level. It was suggested that they get re-biopsied every 1 to 2 years.
There were 43 patients who subsequently underwent treatment after their cancer progressed. Radiation or surgery cured 42 of these patients. The 219 who did not experience progression continued to be monitored regularly throughout the study and had no signs of tumor spread or metastases.
Lead author Scott Eggener, MD, of the University of Chicago Medical Center, said that “close observation” may ensure the quality of life for patients with early stage prostate cancer without increasing the risk of death from tumor progression. “Cure rates appear to be identical when these men choose immediate treatment or delayed treatment when prompted by new information about their condition,” Dr. Eggener said.
To Screen or Not To Screen
According to the American Cancer Society, approximately 1 out of every 6 men in the United States will develop prostate cancer, yet it does not recommend routine screening for the disease. The American College of Physicians and American Academy of Family Physicians actually recommend against routine prostate cancer screening. In February 2009, the US Preventive Services Task Force advised physicians not to screen men over 75 years of age for prostate cancer, concluding that elderly men were more likely to suffer injury or death from diagnosis and treatment of their tumors than from the tumor itself.
Until researchers make a definitive determination about the benefits of prostate cancer, men should discuss the need for screening with their physician. Regular screening is currently recommended for men at high risk for the disease, such as African American men or those with a family history of prostate cancer or BRCA1/2-associated breast cancer. In light of these studies, the real question may not be whether to get screened but instead whether to have early stage tumors treated.