***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
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    Input: BACKGROUND North American investigators have suggested the usefulness of risk-group stratification based on prostate-specific antigen ( PSA ) , clinical stage and biopsy Gleason score for predicting the biochemical outcome of prostate cancer after radical prostatectomy .  There have been no reports of the application of this stratification to early biochemical outcome  after radical surgery in Japanese men . METHODS The study population consisted of 178 men treated with radical retropubic prostatectomy and bilateral pelvic lymph node dissection at Kitasato University Hospital ( n = 110 ) and Kurashiki Central Hospital ( n = 68 ) between October 1992 and May 1999 .  Pathologic and biochemical outcomes after radical prostatectomy were analyzed based on risk-group stratification . Risk groups were further analyzed according to detailed pathologic findings at biopsy . RESULTS The median follow-up period for the 178 patients after radical surgery was 41.5 months ( range , 2.0 - -82.0 months ; mean , 40.9 months ) . Fifty-eight patients experienced PSA failure at a median of 8.0 months following surgery ( range , 0.0 - -58.0 ) . Risk-group stratification distinctly defined groups of pathologic findings in the radical prostatectomy specimens . The proportion of patients with PSA failure for low , intermediate and high-risk groups were 9.5 % , 23.9 % and 56.9 % , respectively ( P < 0.0001 ) . Use of the number of cores with cancer and maximum cancer length in biopsy cores failed to improve risk stratification for PSA outcome in all risk groups . CONCLUSIONS Risk-group stratification based on preoperative variables may significantly improve a physician 's ability to counsel patients about PSA outcome after radical prostatectomy . Further improvement in risk stratification may call for use of variables other than the pathologic information in biopsy cores BACKGROUND Many newly diagnosed patients with prostate cancer have " good risk " disease . The challenge is to identify the minority of these patients with aggressive disease and offer them curative treatment , while sparing the remainder the morbidity of unnecessary treatment . PURPOSE To examine the results of active surveillance with selective delayed intervention in good risk prostate cancer patients . MATERIAL S AND METHODS This was a prospect i ve phase II study of active surveillance of 299 patients . Eighty percent ( 239 patients ) met the criteria for good risk disease : PSA < 10 ng/mL , Gleason < 6 , T < 2a . Twenty percent of patients , all of whom who were age 70 or greater , had Gleason 7 cancer or a PSA above 10 . RESULTS At 8 years , overall survival is 85 % and disease-specific survival is 99 % . A PSA doubling time of < 2 years was linked with likelihood of locally advanced disease . CONCLUSION Watchful waiting is clearly appropriate for elderly prostate cancer patients with high co-morbidities . For good risk , young , healthy patients , this study supports the feasibility of long-term , close monitoring with early intervention for those who progress rapidly . Approximately two thirds of such patients will remain free of treatment over 8 years PURPOSE Several studies have defined risk groups for predicting the outcome after external-beam radiotherapy of localized prostate cancer . However , most models formed patient risk groups , and none of these models considers radiation dose as a predictor variable . The purpose of this study was to develop a nomogram to improve the accuracy of predicting outcome after three-dimensional conformal radiotherapy . MATERIAL S AND METHODS This study was a retrospective , nonr and omized analysis of patients treated at the Memorial Sloan-Kettering Cancer Center between 1988 and 1998 . Clinical parameters of the 1,042 patients included stage , biopsy Gleason score , pretreatment serum prostate-specific antigen ( PSA ) level , whether neoadjuvant and rogen deprivation therapy was administered , and the radiation dose delivered . Biochemical ( PSA ) treatment failure was scored when three consecutive rises of serum PSA occurred . A nomogram , which predicts the probability of remaining free from biochemical recurrence for 5 years , was vali date d internally on this data set using a bootstrapping method and externally using a cohort of patients treated at the Clevel and Clinic , Clevel and , OH . RESULTS When predicting outcomes for patients in the validation data set from the Clevel and Clinic , the nomogram had a Somers ' D rank correlation between predicted and observed failure times of 0.52 . Predictions from this nomogram were more accurate ( P<.0001 ) than the best of seven published risk stratification systems , which achieved a Somers ' D coefficient of 0.47 . CONCLUSION The development process illustrated here produced a nomogram that seems to predict more accurately than other available systems and may be useful for treatment selection by both physicians and patients Purpose : To perform a multivariate analysis to investigate the usefulness of eight preoperative variables as predictors of final pathological stage ( pT ) , positive surgical margins ( PSM ) and biological progression after  radical prostatectomy ( RP )  . Material s and Methods : In 143 patients undergoing RP for T1–T2 prostate cancer , the respective values of age , clinical stage , preoperative  prostate – specific antigen ( PSA )  , prostate – specific antigen density ( PSAD ) , number of positive biopsies ( NPB ) , Gleason score , length of tissue core invaded by cancer ( LTI ) and topography ( uni/bilaterality ) of positive biopsies for predicting extracapsular extension , PSM and biochemical failure ( PSA≥0.05 ng/ml ) were evaluated retrospectively . Univariate and multivariate analyses were applied to define the statistical significance of each variable . Actuarial survival without biological progression was calculated using the Kaplan – Meier method ( log – rank test ) . Results : In this series , 44.8 % of patients had extracapsular extension with 41.3 % PSM . The mean PSA was 12.4 ng/ml . In univariate analysis , LTI ( p<0.0001 ) , NPB ( p = 0.0023 ) , PSA ( p = 0.0039 ) and Gleason score ( p = 0.0136 ) were the most powerful variables to predict pT stage ; however , in logistic regression analysis , LTI was the most predictive feature . For prediction of PSM , some variables ( LTI , NPB and PSA ) were found to be of statistical value in univariate analysis , and LTI in combination with NPB and PSA in multivariate analysis . For biological progression , statistical analysis ( log rank test ) showed PSAD and LTI to be significant predictors . Conclusion : The pathological report regarding the biopsy contains crucial information influencing the prediction of pT stage , PSM and biological progression after RP . LTI , NPB and PSA are the most useful parameters for this purpose Despite years of research and hundreds of reports on tumor markers in oncology , the number of markers that have emerged as clinical ly useful is pitifully small . Often initially reported studies of a marker show great promise , but subsequent studies on the same or related markers yield inconsistent conclusions or st and in direct contradiction to the promising results . It is imperative that we attempt to underst and the reasons why multiple studies of the same marker lead to differing conclusions . A variety of method ological problems have been cited to explain these discrepancies . Unfortunately , many tumor marker studies have not been reported in a rigorous fashion , and published articles often lack sufficient information to allow adequate assessment of the quality of the study or the generalizability of study results . The development of guidelines for the reporting of tumor marker studies  was a major recommendation of the National Cancer Institute – European Organisation for Research and Treatment of Cancer ( NCI – EORTC ) First International Meeting on Cancer Diagnostics in 2000 . As for the successful CONSORT initiative for r and omized trials and for the STARD statement for diagnostic studies , we suggest guidelines to provide relevant information about the study design , preplanned hypotheses , patient and specimen characteristics , assay methods , and statistical analysis methods . In addition , the guidelines provide helpful suggestions on how to present data and important elements to include in discussion s. The goal of these guidelines is to encourage transparent and complete reporting so that the relevant information will be available to others to help them to judge the usefulness of the data and underst and the context in which the conclusions apply 
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EVIDENCE SYNTHESIS The percentage of cancer in biopsies ( overall percentage or the greatest percentage in the most involved core ) was an independent predictor of prostate-specific antigen ( PSA ) and clinical outcomes regardless of the form of treatment and was generally superior to simply counting the number of positive cores .
Tumour quantitation is a promising prognostic tool in the assessment of risk of pCA progression .