prostate cancer is one of the most commonly diagnosed malignancies in men [ 1 , 2 ] . in the usa and several western european countries ,
the incidence rates of pca have exceeded the remaining malignant neoplasms in males [ 3 , 4 ] .
there were 9,273 new pca diagnoses recorded nationwide , according to the national polish cancer register statistics from 2010 .
the diagnosis of pca is based on transrectal ultrasound  guided multiple core prostate biopsy results in view of raised serum prostate  specific antigen ( psa ) levels and/or abnormal digital rectal examination ( dre ) , and/or the presence of trus  confirmed hypoechogenic foci within the marginal zone of the prostate gland , all of which are suggestive of malignancy . the clinical stage of pca is evaluated from the dre and trusbx results . the histological grade of the disease is given a score on the 10point gleason scale , which has been widely used since 1966 [ 6 , 7 ] .
the gleason score ( gl.s . ) is a sum of two individual numbers , representing the two predominant ( out of five possible ) histological pca grades .
additionally , there has been a sharp increase of early stage and low  grade neoplasms diagnosed in younger men .
these trends closely reflect the frequency of psa testing , as well as advances in trusbx techniques . as a result
the combination of psa < 10 ng / ml and gl.s 6 correlates well with small tumour volume , evidenced by a small amount of pca tissue in no more than two samples obtained during trus biopsy .
pca characterised by the aforementioned features is referred to as a low risk tumour [ 9 , 10 ] .
some low  risk prostate cancers meet the criteria of a clinically insignificant disease , one which is unlikely to be the cause of the patient 's death [ 11 , 12 ] .
hence , some low  risk pca men may never need active treatment and can be offered an active surveillance approach . as is based on interval psa testing , dre and yearly trusbx , unless an increase in psa or any abnormal dre
the rationale behind as is to avoid unnecessary radical treatment with its potential risks to the patient , and also to monitor disease progression to the point where the patient can still be cured .
this study was undertaken to evaluate pca characteristics based on clinical features and trusbx results , obtained from low  risk pca patients as potential candidates for active surveillance , and to compare them with the same patients histology results following their radical prostatectomy .
the secondary objective was to assess the level of consistency in reporting trusbx and rp specimens by the same pathologist on two separate occasions , as well as by another independent pathologist .
in this study , all procedures have been carried out in accordance with the ethical standards of the responsible committee on human experimentation and the helsinki declaration of 1975 , as revised in 1983 .
all patients who underwent open radical prostatectomy between 2005 and 2008 had their clinical data , as well as both trusbx and surgical sample histology reports , analysed retrospectively .
subsequently , all low  risk pca cases , eligible for active surveillance , were identified . the inclusion criteria for as were as follows : ( i ) psa < 10 ng / ml ; ( ii ) gl.s .
6 ; ( iii ) a total pca percentage ( % pca ) within the prostate biopsy sample of 25% .
the tnm classification from 2002 was used for pca clinical staging , and where cancer is limited to the prostate ( t2 ) , it is subdivided into either t2a ( the tumor is in half or less than half of one of the prostate gland 's two lobes ) or t2b ( the tumor is in more than half of one lobe , but not both ) , or t2c ( the tumor is in both lobes ) .
the evaluations of pca burden , based on clinical stage and histological grade , were performed prospectively by two independent pathologists , where one examined pre  operative core needle biopsies and post  operative surgical samples , then re  examined them at later stage .
between 2005 and 2008 there were 124 rps , with a mean patient age of 62.7 years ( range , 47 to 74 years ) . in 119 cases ,
the cancer was limited to the prostate ( ct  2 n0 , m0 ) ( table 1 ) . 
  prostate cancer clinical tumour stage ( ct ) in patients treated with radical prostatectomy the low  risk pca inclusion criteria were fulfilled in 8 patients ( 6.45% ) , and subsequently , these men could have been offered as .
features of malignancy , within single core biopsy samples , were found in five men , and within three and two cores in one and two patients , respectively .
cancer positive core biopsies were obtained from the same prostate lobe and did not exceed 25% of total specimen volume .
histologically , gl.s . 4 ( 2 + 2 ) was present in five men , whereas gl.s . 5 ( 2 + 3 ) in three cases , respectively .
risk pca patients are presented in table 2 . 
  serum psa level ( psa ) , psa density ( psad ) , prostate cancer histological grade ( gl.s . ) in 8 low  risk men eligible for active surveillance the tumour stage , determined by the histological examination of radical prostatectomy samples , was originally reported as pt2a , pt2b and pt3a in 4 , 3 and 1 patients , respectively .
one patient was found to have a positive surgical margin , while two had extracapsular extension of cancer .
overall , the reporting concordance of core biopsy specimens , re  examined by the same pathologist ( the time between the initial and subsequent examination ranged from 1 to 5 years ) and then by the second pathologist , with regard to the number of pca positive core biopsies , as well as pca positive radical prostatectomy specimens , was low .
the disagreement in reporting the gleason score for the specimens obtained from trusbx and rp was apparent in 6 and 4 patients , in the second examination by the same pathologist , and in 7 and 6 cases in the examination performed by the second pathologist , respectively ( table 3 ) . 
 
gleason scores as per the first pathologist 's first examination , the first pathologist 's second examination and the second pathologist 's examination of both trusbx and rp specimens trusbx  transrectal ultrasound  guided multiple core prostate biopsy , gl.s. gleason score , rp radical prostatectomy , p1  the first pathologist 's first examination , p1  the first pathologist 's second examination , ( p2 )  the second pathologist 's examination
prostate cancer trigger factors remain unknown and the natural history of pca is unpredictable [ 18 , 19 ] . recently , there have been more prostate cancer cases diagnosed at an earlier stage and in younger men from developed countries .
consequently , this increases the number of potential candidates for the active surveillance approach . according to the capsure ( cancer of the prostate strategic urologic research endeavor ) database , which included 1,884 americans with pca
, 16.4% of men met active surveillance criteria and thus might have avoided early radical treatment .
patients who undergo radical prostatectomy following a period of active surveillance have the same biochemical  free and cancer specific survival as those men who are operated on without delay .
however , active surveillance can trigger a feeling of anxiety in both patient and doctor .
patients are mainly concerned about the continuous need for necessary disease monitoring and prostate biopsies , as well as the fear of impending cancer progression . from the urologists perspective , active surveillance is always associated with a degree of uncertainty , whether or not trusbx results indeed can be relied on in terms of cancer stage and histological grade .
in fact , the most commonly observed limitations of trusbx are undergrading , understaging and underestimating true pca volume [ 22 , 23 ] . in this prospective analysis of data from 124 pca patients who underwent rp , 8 ( 6.45% )
the proportion of men eligible for active surveillance reported by others varies , and can reach up to 57% depending on the inclusion criteria and population used [ 17 , 24 , 25 ] . in our study , when comparing pre and postoperative histology , it appeared that in five out of eight cases the pca grade and stage were significantly underestimated and would not have allowed for as . in three patients pca was present in both lobes ( pt2c ) , in two pca extended beyond the prostate ( pt3a ) , and in one the gleason score was greater than 6 .
pineiro and colleagues , who compared the concordance of trusbx and surgical specimens histological examination findings , reported that out of a total of 164 radical prostatectomies , 36% of pca cases were low 
> 6 , pca extracapsular extension ( pt > 2 ) and the seminal vesicle invasion occurred respectively in 42.4% , 47.5% and 5% initially classed as low  grade pca patients .
the influence of intra and interobserver variability , in preoperative histological diagnosis of pca , on the decision  making process regarding active surveillance , has not yet been reported in the literature . in our study , as in other reports , a proportion of the trusbx and surgical specimens re  examined by the same pathologist was reported differently from the initial reports [ 26 , 27 ] .
to better assess the possible impact of intraobserver variability on the decision for active surveillance , two reports by same pathologist were compared . had the decision about active surveillance been made on the re  examined trusbx histology ,
3 patients would not have been offered it due to a high total pca percentage within the prostate biopsy specimen . in six reviewed reports
the interobserver variability in histology reporting has also been observed by several research groups previously [ 2830 ] . in our study , in two out of eight cases ( 25% ) active surveillance would not have been indicated if the decision was made based on the trusbx report reviewed by the second pathologist .
moreover , six out of eight surgical specimens reviewed by the second pathologist were also less favourably reported .
undoubtedly , trusbx and postoperative histology reports vary due to the sheer volume of the specimens being analysed .
however , we have also noticed a marked intra and interobserver variability in pre and postoperactive histological evaluation of pca .
the observed differences in initial and subsequent assessments may result from the variation in the criteria for interpretation , the actual interpretation of the criteria , and expertise in interpreting the criteria [ 3133 ] .
one should , therefore , always be aware of prostate cancer understaging and undergrading by trusbx when deciding whether active surveillance is in patient 's best interest .
the concept of active surveillance prior to radical treatment in patients with prostate cancer refers back to whitmore 's cornerstone questions :  is cure possible ?
this also reflects the trend to tailor pca management to an individual patient 's needs .
there is a large body of evidence which supports that in selected cases active surveillance is oncologically safe [ 36 , 37 ] .
we recommend , however , maintaining cautious monitoring of all pca patients under active surveillance .
moreover , the decision about active surveillance should , ideally , be made after at least two pathologists have jointly reviewed and agreed on the trusbx histology results .
our study has several methodological strengths , which are : ( i ) clearly defined inclusion criteria for active surveillance ; ( ii ) a second , blinded histological evaluation by the same pathologist ( intraobserver variability ) , as well as a second , blinded histological evaluation by a different pathologist ( interobserver variability ) ; ( iii ) histological reporting in accordance with the isup ( international society of urological pathology ) 2005 guidelines .
the study was limited , however , by a small number of patients , partly retrospective study design , and the 6 to 8core prostate biopsy .
our study has several methodological strengths , which are : ( i ) clearly defined inclusion criteria for active surveillance ; ( ii ) a second , blinded histological evaluation by the same pathologist ( intraobserver variability ) , as well as a second , blinded histological evaluation by a different pathologist ( interobserver variability ) ; ( iii ) histological reporting in accordance with the isup ( international society of urological pathology ) 2005 guidelines .
the study was limited , however , by a small number of patients , partly retrospective study design , and the 6 to 8core prostate biopsy .
the decision about active surveillance prior to radical prostatectomy , offered to low  risk prostate cancer patients , should be made with full awareness of the limitations associated with prostate biopsy .
our study has identified significant intra and interobserver variability where pca histology reports differed , and were often undergraded .
therefore , the decision about active surveillance of low  risk prostate cancer patients should be made carefully , taking into account all available clinical and histological data , and after at least two pathologists have jointly reviewed and agreed on the trusbx histology results .
further prospective studies with a larger number of patients need to identify the most adequate histological approach for an optimal selection of candidates suitable for active surveillance .
 introductionactive surveillance ( as ) is always associated with a degree of uncertainty , whether or not prostate biopsy ( trusbx ) results indeed can be relied on for evaluation of cancer stage and histological grade , as the most commonly observed limitations of trusbx are undergrading , understaging and underestimating true prostate cancer ( pca ) volume . 
 we evaluated prostate cancer characteristics in men who could have been offered active surveillance based on clinical features and trusbx results , and compared them with the same patient 's histology results following their radical prostatectomy ( rp ) . 
 moreover , we assessed the level of consistency in reporting trusbx and rp specimens by the same pathologist on two separate occasions , as well as by another independent pathologist.material and methodsall patients who underwent rp between 2005 and 2008 had their medical records reviewed retrospectively . 
 all histological specimens were prospectively re 
  evaluated by the same pathologist , as well as by a second to assess for intra and interobserver variability , respectively.resultseight out of a total of 124 patients who underwent rp could have been offered as on the basis of initial microscopic reports . 
 however , there was significant intra and interobserver variability . 
 the differences in the histological grade of the specimens obtained from trusbx and rp , reported by the same pathologist and by the second pathologist were apparent in 6 and 4 cases , and in 7 and 6 patients , respectively.conclusionswe recommend that the decision about as should be made after at least two pathologists have jointly reviewed and agreed on the trusbx histology results . 
INTRODUCTION
MATERIAL AND METHODS
RESULTS
DISCUSSION
Strengths and limitations of the study
CONCLUSIONS