CLINICAL UPDATE
Risks in ( not ) diagnosing prostate cancer
Various colleges and government agencies seem to provide mixed messages on prostate cancer detection . When it comes to biopsies , small changes in methods have the potential to decrease negative biopsies and improve safety .
Screening recommendations and use varies
The American Urological Association has just downgraded recommendations for prostate cancer screening to align more with the more conservative U . S . Preventive Services Task Force ( USPSTF ), which says the harms outweigh the benefits for prostate cancer screening . This policy change has to be seen in the light of the Urologists in the USA being very aggressive on prostate cancer screening for many years . At the same time , Prof Bruce Armstong ( Director of Australian Agency for Health and Welfare ), who has long opposed prostate cancer screening , changed his mind and now believes benefits are likely .
The European prostate screening study group from Goteborg ( Sweden ) had the most compelling evidence for a benefit from prostate cancer screening with similar numbers needed to treat as breast and colon cancer screening trials . Interestingly Australia , like Sweden , has one of the world ’ s highest incidences and mortality rates of prostate cancer . There are no studies of prostate cancer screening in an Australian population .
This uncertainty leads to disparate practices regarding PSA testing amongst Australian doctors – not acting on an elevated result is risky .
The Goteburg study used a PSA cutoff of 3.2 ng / ml to suggest biopsy . PSAs above this level should at least prompt discussion of the risk of prostate cancer with the patient . New parameters such as free to total ratio and proPSA can be added to PSA in online calculators to refine an individual ’ s risk of a biopsy diagnosing cancer ( http :// deb . uthscsa . edu / URORiskCalc / Pages / calcs . jsp ). proPSA is available via Clinipath as a PHI-prostate health index test that is not MBS-rebateable .
MRI use
Currently , MRI use in diagnosis of prostate cancer involves targeting an abnormal area , and reducing the number of biopsies required . The negative predictive value of MRI ’ s is such that it will not replace biopsy yet but it can give useful information regarding staging and reassure patients in the setting of a negative biopsy with a rising PSA . Unfortunately there is no rebate for prostate
� Prostate cancer MRIs .
MRI ( which costs patients $ 500-700 ).
Prostate biopsy
Prostate biopsy is done with a transrectal ultrasound probe to image the gland ( TRUS / PB ). The biopsy needle passes through either the rectal mucosa ( transrectal ) or the skin ( transperineal ). The risk of infectious complications following TRUS / PB has increased up to fourfold and up to 10 % of patients admitted with post biopsy septicemia require ICU admission
( with rare fatalities ). This increasing risk is largely due to the increasing prevalence of fluoroquinolone resistance . Predictive risk factors include frequent antibiotics usage , frequent travel to SE Asia ( livestock antibiotic feeding ), diabetes , and increased number of biopsies taken .
One effective strategy to reduce infectious complications was pioneered locally at Hollywood Hospital with the use of betadine rectal suppositories at the time of biopsy . A randomised trial has just been published from Canada demonstrating a significant risk reduction with this technique .
In areas of high fluoroquinolone resistance , faecal cultures can identify antibiotic resistance and prompt adjusted prophylaxis in individual cases , while the same strategy
By Clinical A / Prof Justin Vivian ,
Urologist .
Tel 9382 4999
can be used in individuals at risk ( immune suppressed , frequent travelers , or prolonged antibiotic users ).
Avoiding the contaminated rectum and performing transperineal biopsies is another solution . Reported sepsis rates of 0.2 % following transperineal biopsy compare favourably to the 2.8 % for transrectal biopsy ( with similar prostate cancer detection rates ). The drop in septic complications following transperineal biopsy is more significant as these patients had more biopsies ( 14 ) than the transrectal group ( 10 ).
References Sanders et al , ANZ J Surg 83 ( 2013 ) 246-248 , Infectionrelated hospital admissions after transrectal biopsy of the prostate . Tsivian et al , Urology 2013 May 19 . pii : S0090- 4295 ( 13 ) 00372-5 . doi : 10.1016 / j . urology . 2013.01.071 . Lawrentschuk Nathan , ANZ J Surg ( 2013 ) 197-198 , The role of magnetic resonance imaging in prostate cancer Barentsz JO et al , ESUR prostate MR guidelines Hugosson J , Carlsson S , Aus G , et al . Mortality results from the Göteborg randomised population-based prostatecancer screening trial . Lancet Oncol 2010 ; 11 : 725-732 . Andriole GL , Crawford ED , Grubb RL 3rd , et al . Prostate cancer screening in the randomized Prostate , Lung , Colorectal , and Ovarian Cancer Screening Trial : mortality results after 13 years of follow-up . J Natl Cancer Inst 2012 ; 104 : 125-132 . Schröder FH , Hugosson J , Roobol MJ , et al . Prostate-cancer mortality at 11 years of follow-up . N Engl J Med 2012 ; 366 : 981-990
Declaration : The author treats prostate cancer ; no competing interests identified .
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