Prostate Cancer Screening

Prostate Cancer and Screening: An Update
December 19th 2004
Phillips, Erwin Arthur

•What do we know about prostate cancer?
•When does it make sense to screen?
•What do we tell patients?


•Prostate Cancer is a leading cause of mortality and morbidity worldwide


Risk Factors include:
•High animal fat and protein
•Family History
•Ethnicity


Clinical Features:

Most often asymptomatic
Lower urinary tract symptoms (BPH)
Frequent urination, especially at night
Inability to urinate
Trouble starting or holding back urination
A weak or interrupted flow of urine
Painful or burning urination
Blood in the urine or semen
Painful ejaculation
Frequent pain in the lower back, hips, or upper thighs


Diagnosis is by:

•Digital Rectal Examination (DRE)
•Prostate Specific Antigen (PSA)
•Transrectal ultrasound with or without Biopsy (TRUS)


Other than the size of the prostate and the age of the person PSA may be raised by the following:
Urinary Tract Infections, ejaculation or vigorous exercise in the past 48 hours, biopsy of the prostate in the past 6 weeks and DRE in the past 48 hours


Treatment of Prostate Cancer

Considering grade and stage, age and health, values and feelings (about benefits and harms of each option. )
•Radical Prostatectomy
•Radical Radiotherapy
•Conservative Management


Prevention (this is controversial)

•Diet (lowfat)
•Exercise ??
•Screening(this is very controversial)
•High Intensity Focused Ultrasound (experimental)


Lets talk a little bit more about screening
In 1968 Wilson and Junger came up with some guidelines to help those making decisions about implemeting screening programmes. While 1968 is a very long time ago not much has changed. The guidelines continue to be valuable. This is what they said:

The condition is an important health problem
Its natural history is well understood
It is recognisable at an early stage
Treatment is better at an early stage
A suitable test exists
An acceptable test exists
Adequate facilities exist to cope with abnormalities detected
Screening is done at repeated intervals when the onset is insidious
The chance of harm is less than the chance of benefit
The cost is balanced against benefit


Guidelines
The reality is that there is alot of controversy about the benefits of screening for prostate cancer. (That is looking for illness in people who do not have symptoms) If we for example look at the following organisations' positions on prostate cancer screening(PCS) you would find acknowledged that the info supporting its benefits is very limited if not non-existant. Interestingly enough Cancer Societies and Urologists continue to push prostate cancer screening. Hopefully this has nothing to do with the fact that they have financial incentive to do so and instead is explained by thier inability to understand the published information on the subject. "No randomized clinical trials have ever demonstrated that early detection and aggressive treatment of prostate cancer reduce mortality;
The treatments usually mobilized after a positive PSA test and biopsy (radical prostatectomy, radiation therapy or castration) are associated with severe side effects including impotence and incontinence." Berry 2001

Some of the bodies that have opinions and make recomendations about PCS:
American Cancer Society http://caonline.amcancersoc.org/cgi/content/full/53/1/27#SEC6U.S. Preventive Services Task Force http://www.ahcpr.gov/clinic/uspstf/uspsprca.htm
US Centers for Disease Control http://www.cdc.gov/cancer/prostate/prostate.htm UK NHS Screening http://www.cancerscreening.nhs.uk/
Australia http://www7.health.gov.au/pubs/ahtac/prostate.htm
University of California Irvine http://www.ucihealth.com/news/UCI%20Health/prostate.htm Canada http://www.prostatecancer.ca/english/living/screening.html

Recommendations
In theory PCS may help. There is not solid evidence that it does. There is evidence that it may cause harms. We need to communicate this effectively to the public as opposed to saying it is a cure-all or a complete waste of time. Several large studies are underway with preliminary results due out in 2006 and difinitive around 2015. For now we need informed consent clearly explaining the risks and potential benefits.

•PSA+ DRE offered annually from age 50
•Informed decision (pros and cons)
•High risk from 45
•Greater risk from 40

References

•Nelson, W. G. et al Mechanisms of Disease: Prostate Cancer, New England Journal of Medicine 2003:339;366-81
•Mazhar, D and Waxman J Review:Prostate Cancer, Postgraduate Medical Journal 2002; 78,590-595
•Kakehi, Y. Watchful waiting as a treatment option for localised prostate cancer in the PSA era, Review Article, Japanese Journal of Clinical Oncology 2003; 33(1) 1-5
•Sabichi, A L et al, Frontiers in Cancer prevention Research, Cancer Research 63, 5649-5655, September 2003
•Selly S et al, Diagnosis Management and Screening of Early Localised Prostate Cancer Health Technology Assessment 1997, Vol 1; No 2


Further Reading (prostate)

•Watson E, Jenkins L, Bukach C Austoker J. The PSA test and prostate cancer: Information for primary care. NHS Cancer Screening Programmes, Sheffield 2002
•Tudiver F,et al What influences family physicians’ cancer screening decisions when practice guidelines are unclear or conflicting? The Journal of Family Practice, September 2002 Vol 51, No 9
•Summary of Evidence Last Modified: 10/20/2004
National Cancer Institute- www. Cancer.gov (see prostate cancer, prevention, screening, treatment and levels of evidence)
•Prostate Cancer Screening Australian Health Technology Advisory Committee Report http://www7.health.gov.au/pubs/ahtac/prostate.htm
•Russell Harris, MD, MPH and Kathleen N. Lohr, PhD Screening for Prostate Cancer: An Update of the Evidence for the U.S. Preventive Services Task Force, Annals of Internal Medicine 3 December 2002 Volume 137 Issue 11 Pages 917-929

Further Reading (Screening)


•NHS (UK) Screening Programme. http://www.cancerscreening.nhs.uk/
•Sennfalt K, Sandblom G, Carlsson P, Varenhorst E,Costs and Effects of Prostate Cancer Screening in Sweden: A 15-year follow-up of a randomized trial Scandinavian Journal of Urology & Nephrology. 38(4):291-298, 2004.Guide to Clinical Preventive Services http://www.ahrq.gov/clinic/cps3dix.htm
•Greenhalgh T, How to read a paper: Papers that report diagnostic or screening tests BMJ 1997;315:540-543

Feel free to contact me at:
e.arthurphillips@gmail.com