Prostate cancer: the controversies and their solutions
(Feb 9, 2012)
Prostate cancer is one of the most common cancers affecting men in the United States with estimates of 240,890 new cases being diagnosed and 33,720 men dying from prostate cancer in 2011.
The recent U.S. Preventative Services Task Forces’ (USPSTF) recommendation against the use of prostate-specific antigen (PSA) based screening for prostate cancer in men 75 years or older has stimulated a heated discussion regarding the benefits and harms of early detection screening programs and treatment for prostate cancer. For younger men, the task force stated “current evidence is insufficient to assess the balance of benefits and harms of prostate cancer screening in men younger than age 75 years.”
However, there may still be great clinical value in identifying and treating prostate cancer in its early stages for many patients. In fact, several of the prostate cancer studies evaluated by the task force showed a definite benefit of screening in younger men. One trial of men in their 50s and early 60s showed a 44 percent relative risk reduction in prostate cancer death rate after a median of 14 years.
Prostate cancer screening is typically performed through a blood test to identify the presence of PSA, along with a prostate examination/digital examination. The problem is that PSA, a protein, is also produced by a noncancerous condition called benign enlarged prostates (BPH), in addition to prostate cancer. Therefore the presence of PSA is not specific to prostate cancer. This can lead to falsely positive test results, where the PSA test is abnormal, without the actual presence of prostate cancer.
Up to 50 percent of men may have lower risk and/or slow-growing prostate cancer at the time of diagnosis and many of these men do not need immediate treatment. There is a growing body of evidence to suggest prostate cancer patients currently are overdiagnosed and overtreated. However, there is little doubt that early detection of prostate cancer screening has led to better chances for cure and is supported by the following observations:
• Prior to 1990, men had less than a 35 percent chance for curative success, compared to 90 percent of men who present today.
• Epidemiological data have shown a 41 percent decrease in prostate cancer mortality in the U.S. between 1990 and 2008.
Studies suggest that more than 50 percent of this reduction is due to early detection.
Ultimately, men need to be well-informed before making decisions about screening and treatment for prostate cancer. The American Cancer Society and the American Urology Association both advocate screening be performed according to patient preference after an explanation of the potential benefits and harms.
A potential solution to the concern of overtreatment of prostate cancer is a relatively new approach in the management of these cancers known as “active surveillance.” Active surveillance allows carefully selected patients with early stage, low-grade tumors (less aggressive) to avoid being treated. All the while, they are being carefully monitored to detect any disease progression before it escapes the realm of curability. Studies show that approximately 33 percent of men being managed with active surveillance will eventually require some form of definitive treatment. Patients managed with active surveillance are recommended to undergo treatment if the cancer shows evidence of significant growth or demonstrates a more aggressive pattern on pathological evaluation. The goal is always to treat cancer when it is still curative.
A large Johns Hopkins University study recently published in the Journal of Clinical Oncology has offered strong evidence that active surveillance is a reasonable option for many men diagnosed with low grade/stage prostate cancer.
Physicians at Genesis Healthcare Partners in San Diego are coordinating a new active surveillance research study incorporating sophisticated contemporary diagnostic procedures such as urology dedicated MRI protocols and image-guided re-biopsy procedures in cases where more significant disease is suspected. Men meeting the criteria for the Genesis active surveillance program undergo a thorough initial evaluation, followed by periodic re-evaluations that include PSA tests, digital rectal exams, biopsies, multiparametric MRI exams and regular consultation with their physician.
If progressing cancer becomes evident, more aggressive treatment options may be recommended to eradicate the cancer. Minimally invasive treatment options such as robotic surgery, traditional open Radical Prostatectomy, Smart Arc Image Guided Radiotherapy (IGRT) and CyberKnife Stereotactic Body Radiotherapy (SBRT) are among the best therapeutic alternatives available.
Active surveillance may be the answer to the concern that too many men are being diagnosed and treated for prostate cancer, treatment which may not always be necessary.
Gaylis is a urologist and medical director of Genesis Healthcare Partners.