Guidelines for Cancer Prevention, Early detection & Screening. Prostate Cancer

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1 Guidelines for Cancer Prevention, Early detection & Screening Prostate Cancer Intervention Comments & Recommendations For primary prevention, it has been suggested that diets low in meat & other fatty foods of animal origin may prevent 10-20% of cases of Digital rectal examination (DRE) for screening Representative estimates of sensitivity & specificity of DRE ranged between 33-58% & 96-99% DRE was found to have a positive predictive value of 28-47% & negative predictive value of 99% However there has NOT been any randomized controlled study (RCT) that compared DRE alone with no screening in reducing mortality Three case-control studies evaluated the association between DRE & mortality, which showed mixed results: 1. Two studies showed screening by DRE did not reduce mortality from nor 1

2 prevent metastatic. Serum Prostate Specific Antigen (PSA) for screening 2. The 3 rd study showed a strong inverse association between DRE & prostatic cancer mortality Accuracy of PSA tests as screening depends on the value used to define an abnormal PSA result At cut-off point of 4.0ng/ml or higher, the sensitivity & specificity of PSA in detecting cancers appearing within 2 years after screening was 73% & 85 % The only RCT of PSA & DRE screening reported a benefit from screening (69% decrease in mortality rate from ). However, the trial design & published analysis were considered scientifically flawed. Transrectal Ultrasound (TRUS) of prostate as screening Because of its low sensitivity & specificity, TRUS is generally used as a diagnostic tool for work-up of an abnormal screening test, rather than as a screening procedure Chemoprevention with taking oral drug Finasteride 5mg daily RCT showed chemoprevention with Finasteride reduces the incidence of, but the evidence is still insufficient to determine whether chemoprevention with finasteride reduces mortality from. Thus it is NOT recommended. Local considerations of Serum PSA as screening procedure In Hong Kong, the median age at diagnosis & death from is around 74 & 78 years respectively. The latter approximates the male average life expectancy of 78 years. Despite the increase in incidence & mortality rates of during the past decade, they remain substantially lower than those in most Western countries. Coupled with the fact that 2

3 specificity of PSA is not very high, PSA screening in Hong Kong is likely to produce a substantial false positive rate. Besides, the detection of slow growing prostate cancer through screening (many of which might remain silent during a patient s lifetime), followed by therapeutic interventions that carry significant risks of adverse effects, may offer little clinical benefit Thus we recommend clinicians to discuss with patients the potential benefits & possible hams of routine PSA screening for asymptomatic men so as to allow men to make informed choice about PSA testing. Serial monitoring of PSA to note the trend may be considered. Local consideration of DRE as screening procedure In the case of DRE, it has limited sensitivity as an early detection test, and the benefits of screening for are also not proven. However, DRE has a higher specificity than PSA & many doctors are practicing DRE for early detection of prostate abnormalities. On the whole, there is still insufficient evidence to recommend for or against screening by DRE in asymptomatic men After due consideration, it is fair to make the following comments: 1. Prostate cancer screening is still controversial due to a lack of evidence from properly conducted randomized controlled trials that show mortality reduction from. 2. Screening tests are able to detect at an early stage, but it is still not clear whether this earlier detection and consequent earlier treatment leads to any change in natural history and outcome of the 3

4 disease. 3. At present, there is still insufficient evidence to recommend for or against routine screening for using PSA test. We recommend clinicians to discuss with patients the potential benefits & possible hams of routine PSA screening for asymptomatic men so as to allow men to make informed choice about PSA testing. It is important to note that PSA as screening test has frequent false-positive results and unnecessary anxiety, biopsies and potential complications of treatment of some s that may never have affected a patient s health can occur. 4. There is insufficient evidence to recommend for or against screening by DRE in asymptomatic men. 5. Both Transrectal ultrasound of prostate as screening and Chemoprevention by taking finasteride are not recommended. Appendix: Recommendations of Other Countries PSA DRE Remarks The US Preventive Services Task Force US- Major organizations including American Academy of Family Physicians, American College of Physicians, American Medical Insufficient evidence to recommend for or against routine screening for using PSA Recommended clinicians to discuss with patients the potential benefits & possible harms of PSA screening, considering patient preferences & Insufficient evidence to recommend for or against routine screening for using DRE None of these organizations endorses universal or mass screening for any group of men 4

5 Association & American Urologic Assoication American Cancer Society individualize the decision to screen Both PSA & DRE should be offered annually, beginning at age 50, to men who have at least a 10-year life expectancy Canada The Canadian Task Force on Periodic Health Care UK- National Health Services (NHS) Prostate Cancer Risk Management Program Australia- National Health Priority Action Council In 1994, recommended against the routine use of PSA as part of periodic health check In 2001, the Council recommended promoting informed choice by men about Insufficient evidence to recommend that physicians discontinue use of DRE in men aged 50 or over Any man considering PSA test will be given detailed information to make informed choice about whether or not to proceed with the test. The National Screening Committee has reaffirmed that asymptomatic men should not be invited for PSA testing The current national policy is that asymptomatic men should not be screened for 5

6 PSA testing & early detection of through education for general practitioners & community as a priority action in cancer control Dr. Anthony C.H. YING Chairman, Cancer Detection & Prevention Subcommittee The Hong Kong Anti-Cancer Society April