An appraisal of analytical tools used in predicting clinical outcomes following radiation therapy treatment of men with prostate cancer: a systematic review.
BACKGROUND
Prostate cancer can be treated with several different modalities, including radiation treatment. Various prognostic tools have been developed to aid decision making by providing estimates of the probability of different outcomes. Such tools have been demonstrated to have better prognostic accuracy than clinical judgment alone.


METHODS
A systematic review was undertaken to identify papers relating to the prediction of clinical outcomes (biochemical failure, metastasis, survival) in patients with prostate cancer who received radiation treatment, with the particular aim of identifying whether published tools are adequately developed, validated, and provide accurate predictions. PubMed and EMBASE were searched from July 2007. Title and abstract screening, full text review, and critical appraisal were conducted by two reviewers. A review protocol was published in advance of commencing literature searches.


RESULTS
The search strategy resulted in 165 potential articles, of which 72 were selected for full text review and 47 ultimately included. These papers described 66 models which were newly developed and 31 which were external validations of already published predictive tools. The included studies represented a total of 60,457 patients, recruited between 1984 and 2009. Sixty five percent of models were not externally validated, 57% did not report accuracy and 31% included variables which are not readily accessible in existing datasets. Most models (72, 74%) related to external beam radiation therapy with the remainder relating to brachytherapy (alone or in combination with external beam radiation therapy).


CONCLUSIONS
A large number of prognostic models (97) have been described in the recent literature, representing a rapid increase since previous reviews (17 papers, 1966-2007). Most models described were not validated and a third utilised variables which are not readily accessible in existing data collections. Where validation had occurred, it was often limited to data taken from single institutes in the US. While validated and accurate models are available to predict prostate cancer specific mortality following external beam radiation therapy, there is a scarcity of such tools relating to brachytherapy. This review provides an accessible catalogue of predictive tools for current use and which should be prioritised for future validation.
South Australian Prostate Cancer Clinical Outcomes Collaborative (SA-PCCOC), Adelaide, Australia.
Elspeth
E
Raymond
South Australian Prostate Cancer Clinical Outcomes Collaborative (SA-PCCOC), Adelaide, Australia. Michael.ocallaghan@health.sa.gov.au.|Freemasons Foundation Centre for Men's Health, University of Adelaide, Adelaide, Australia. Michael.ocallaghan@health.sa.gov.au.|SA Health, Repatriation General Hospital, Urology Unit, Daws Road, Daw Park, 5041, SA, Australia. Michael.ocallaghan@health.sa.gov.au.|Flinders Centre for Innovation in Cancer, Bedford Park, Australia. Michael.ocallaghan@health.sa.gov.au.
Michael E
ME
O'Callaghan
Joanna Briggs Institute, University of Adelaide, Adelaide, Australia.
Jared
J
Campbell
South Australian Prostate Cancer Clinical Outcomes Collaborative (SA-PCCOC), Adelaide, Australia.|Freemasons Foundation Centre for Men's Health, University of Adelaide, Adelaide, Australia.
Andrew D
AD
Vincent
South Australian Prostate Cancer Clinical Outcomes Collaborative (SA-PCCOC), Adelaide, Australia.|Centre for Population Health Research, University of South Australia, Adelaide, Australia.
Kerri
K
Beckmann
Centre for Population Health Research, University of South Australia, Adelaide, Australia.
David
D
Roder
Epidemiology & Preventative Medicine, Monash University, Clayton, Australia.
Sue
S
Evans
Epidemiology & Preventative Medicine, Monash University, Clayton, Australia.
John
J
McNeil
Radiation Oncology, Alfred Health, Melbourne, Australia.
Jeremy
J
Millar
Epidemiology & Preventative Medicine, Monash University, Clayton, Australia.|School of Public Health and Preventive Medicine, Monash University, Clayton, Australia.
John
J
Zalcberg
Adelaide Radiotherapy Centre, Adelaide, Australia.
Martin
M
Borg
South Australian Prostate Cancer Clinical Outcomes Collaborative (SA-PCCOC), Adelaide, Australia.|Freemasons Foundation Centre for Men's Health, University of Adelaide, Adelaide, Australia.|Centre for Population Health Research, University of South Australia, Adelaide, Australia.|Joanna Briggs Institute, University of Adelaide, Adelaide, Australia.|Discipline of Surgery, University of Adelaide, Adelaide, Australia.
Kim
K
Moretti
D006801:Humans; D008297:Male; D049451:Nomograms; D011379:Prognosis; D011471:Prostatic Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D016896:Treatment Outcome
Biochemical recurrence; Nomogram; Outcomes; Prostate cancer; Survival; Systematic literature review