Merel Nissenberg, President, National Alliance of State Prostate Cancer Coalitions was part of a panel discussing the pros and cons of screening for prostate cancer at the IMPaCT meeting convened by the DoD CDMRP in Atlanta. She has given me permission to share her presentation with you.
NATIONAL ALLIANCE OF STATE PROSTATE CANCER COALITIONS
PROSTATE CANCER SCREENING
The consumer perspective on prostate cancer screening is affirmatively proactive and recognizes that a better term would be “early detection”. Who would not opt for early stage, curable prostate cancer rather than late-stage disease? We need to separate out the issue of detection from the issue of treatment, so that there is room in any discussion for those patients who are diagnosed but who then select watchful waiting or active surveillance rather than definitive treatment at the outset.
To hear the naysayers argue against screening, one would be tempted to think that all prostate cancer is clinically insignificant. Not true. Simply put, to counter the arguments of those opposed to performing Prostate Specific Antigen Testing and Digital Rectal Exams on a regular basis, we believe that over-detection does NOT have to mean over-treatment. That is to say, a man should be able to learn if he has cancer – clinically significant cancer – and then have an opportunity to make an informed decision as to which treatment – if any –to choose. [That decision should be made in concert with his physician and be appropriate for his particular stage of disease, i.e. tumor location and size; Gleason grade; and whether or not his prostate cancer is still organ-confined or has spread, along with other risk factors.]
Most organizations advocate for prostate cancer screening but differ as to the age and frequency for testing. Some insist that a patient be counseled first on the benefits and risks of such screening (not on the benefits of early diagnosis or the risk of a late one). We believe that begs the point.
Several organizations advocate for a baseline PSA and DRE at age 40 – such as the National Comprehensive Cancer Network and the ACS – as to African-American men. The National Alliance of State Prostate Cancer Coalitions has adopted Early Detection Guidelines urging men to have their first PSA and DRE at age 40 OR at 35 if they are high risk – including African American men or those with a known or an indeterminate family history of prostate cancer. NASPCC’s Guidelines further state that every man is responsible to know and keep track of his PSA and that it is the change in the PSA over time, rather than the absolute number, that is significant.
The benefits of prostate cancer “screening” through the use of PSA are many, including its preponderant ability to identify clinically significant prostate cancer; to detect prostate cancer when it has more favorable clinical and pathologic features; and to identify groups of men who are at increased risk for the disease.
Most importantly, by augmenting the use of the DRE – formerly the gold standard for prostate cancer detection- the use of PSA since its inception has led to definitive stage migration, meaning more cases of localized disease at time of diagnosis and fewer of advanced or metastatic disease. In fact, the age-adjusted prostate cancer-specific mortality has declined by 32.5% since 1992, according to Kopec in the Journal of Urology in 2005.
We can conclude therefore that more than simply clinically insignificant prostate cancers are being detected and treated.
We know that DRE’s alone can be deficient as prostate cancer screening tools. They are dependent upon the skill of the examiner, and are less than reliable when there are different examiners each time; we also know that for those prostate cancers not arising at the back of the gland a negative DRE would be falsely reassuring.
While we recognize the value of the PSA test we do not advocate its use simply as an absolute number because prostate cancer can be present with a low PSA, and a high PSA does not always mean cancer – it can mean BPH or prostatitis. Thus there are various strategies and refinements currently being utilized to make PSA more sensitive and specific for prostate cancer, such as monitoring PSA velocity, i.e. increases greater than .5 per year, free-versus-bound PSA, and PSA doubling time. Other tests are on the horizon.
In short, we believe that knowledge is power. We do not advocate ignorance for the patient of his own true health status. As with most solid tumors, early detection is key to successful treatment, when the tumor burden is small and there is less chance that the cancer has spread.
But just as mammography is not 100% sensitive and specific, and some feel it should not be routinely performed for women, yet its benefits are nearly universally acknowledged. So, too, DRE’s and PSA’s, while not perfect, remain the best hope for early detection of prostate cancer and thus a greater chance for curative, rather than palliative care. That said, more research is needed to develop even better diagnostic tools.
Consumer advocates are starting to address the glaring need for increased prostate cancer education and awareness for as-yet undiagnosed men, as well as for clinicians. There is still much to do and learn in the area of prostate cancer screening for both healthcare providers and prospective and current patients.
In the meantime, we believe that the DRE and the PSA should be a regular part of every man’s health exam, on at least a yearly basis.
In conclusion, while there are opportunities for health care educators and clinicians to help men and their families make informed decisions regarding detection and treatment choices, without knowledge and opportunity for early detection those opportunities are meaningless. Thank you.