prostate biopsy has been widely performed in clinical practice in patients with high prostate - specific antigen ( psa ) levels , and the incidence of prostate cancer has increased . although a serum psa level of 3.0 or 4.0 ng / ml is used as a cutoff value for screening for prostate cancer , it is relatively difficult to discriminate prostate cancer from benign prostatic hyperplasia ( bph ) in men with gray - zone psa values ( 4 - 10 ng / ml ) . to increase the diagnostic accuracy of prostate biopsy , various parameters including psa velocity , percent free psa , age reference psa ranges , and psa density ( psad )   have been used in clinical practice . psad values of 0.15 are generally regarded as being highly suspicious of prostate cancer . with developments in prostate ultrasound and biopsy instruments , prostate biopsy can be performed under local anesthesia on an outpatient basis in most cases . the development of prostate biopsy techniques has reduced patient discomfort , but a considerable number of patients still complain of pain or discomfort . some patients refuse to undergo prostate biopsy because they recall the pain of previous biopsy procedures . to reduce this discomfort , prostate biopsy is sometimes performed under general anesthesia or spinal anesthesia , which is often costly and time consuming . in cases in which the psa level is within the gray zone , but the psad value is low , this increased psa level is mostly attributed to bph , suggesting a lower possibility of prostate cancer . if combined prostate biopsy and transurethral resection of the prostate ( turp ) is safe , the pain or discomfort experienced when prostate biopsy is performed separately can be avoided . this study was conducted to examine whether simultaneous transrectal prostate needle biopsy ( tpnb ) is safe and effective in patients who are scheduled for turp because of an increase in psa levels . this study included a total of 42 patients aged 60 years who had psa levels of 4 to 10 ng / ml and psad values of 0.12 and who underwent combined tpnb and turp at our hospital . the mean age , prostate volume , psa level , and psad value of the patients were 71.35.7 years , 75.927.7 g , 6.02.0 ng / ml , and 0.0840.026 , respectively ( table 1 ) . prostate volume was calculated by using the following formula : where l = length , w = width , and h = height . after prostate biopsy was performed with the patient under spinal anesthesia , the patient 's position was changed into the lithotomy position for turp . prostate biopsy was conducted under transrectal ultrasound guidance by using the 8 core method before february 2008 and the 12 core method after march 2008 . after surgery , the degree and duration of fever , the absence or presence of sepsis , and the development of complications , such as epididymitis or orchitis , were assessed . fever was defined when the highest measurement was 37.5. the diagnostic accuracy was determined , and the results of histological examinations were evaluated according to tpnb alone or combined tpnb and turp . the gleason score was measured in patients with a confirmed diagnosis of prostate cancer ( pca group ) . clinical characteristics , prostate volume , psa , and psad were analyzed in patients with a confirmed diagnosis of bph ( bph group ) and in the pca group . diagnostic accuracy was analyzed in two groups of patients according to age : those < 70 years and those 70 years . all statistical analyses were performed by using spss 12.0 ( spss inc , chicago , usa ) . comparisons of clinical characteristics and parameters were made by using the mann - whitney test . the mean volume of the resected specimen after turp was 32.421.6 g. the durations of urethral catheter placement and admission were 2.60.8 and 5.51.6 days , respectively ( table 1 ) . of the total 42 patients , fever was noted in 9 patients ( 21.4% ) , 4 ( 9.5% ) of whom had a fever of 38. all of the 9 patients had fever the day after surgery , and the fever subsided within 24 hours . there was no significant difference in the duration of hospital stay between the patients with fever and those without . of the total 42 patients , 6 ( 14.3% ) were definitively diagnosed as having prostate cancer . prostate cancer was diagnosed in 2 patients by tpnb alone , in 3 patients by turp alone , and in 1 patient by both procedures . the gleason score was 6 points in 3 patients and 7 points in 3 patients ( table 2 ) . the psa level was 4.77 ng / ml in the pca group and 6.22 ng / ml in the bph group , but the difference was not statistically significant . the psad value was 0.075 in the pca group and 0.086 in the bph group , but the difference was not statistically significant ( table 3 ) . according to the reference age of 70 years , there were no significant differences in prostate volume , the psa level , or the psad value between the two age groups of < 70 years and 70 years . the diagnostic accuracy was 25.0% ( 4/16 ) in the patients aged < 70 years and 7.8% ( 2/26 ) in the patients aged 70 years ( table 4 ) . with advancements in psa screening tests , transrectal ultrasound , and biopsy instruments , prostate biopsy is widely performed in clinical practice . although complications after prostate biopsy are not serious , many patients hesitate to undergo prostate biopsy because of pain or discomfort . zisman et al reported that about 96% and 89% of patients undergoing prostate biopsy complained of pain and discomfort , respectively . many attempts to reduce pain during prostate biopsy have been made . among them , infusion of lidocaine jelly is simple to use but its effect is controversial . a previous study documented that about 82% of patients reported " no " to the question " will you undergo prostate biopsy again if needed ? " . when prostate biopsy is performed under general anesthesia to avoid such discomfort or pain , the procedure costs are increased , although patient discomfort or pain can be reduced . such problems can be solved if combined tpnb and turp are performed in patients who need prostate biopsy although there is a low possibility of prostate cancer based on a psa level within the gray zone but a low psad value . shen et al reported that combined tpnb and turp is safe without notable complications other than fever , which agrees with our results . of the total 42 patients in the present study , 9 ( 21.4% ) had fever after surgery , 4 ( 9.5% ) of whom had a fever of 38. fever subsided in all 9 patients within 24 hours . there were no significant differences in the durations of urethral catheter placement and hospital stay between the patients with fever and those without fever . it has been reported that fever occurs in 4.4% or 6.2% of patients after tpnb alone . in our study , a fever of 38 occurred in 9.5% of the patients without any significant difference between tpnb alone and combined tpnb and turp . palisaar et al indicated that open radical retropubic prostatectomy after turp gives favorable surgical and functional outcomes without an increase in the incidence of complications or sexual dysfunction . in our study , open radical retropubic prostatectomy was performed on 5 of the 6 patients with a confirmed diagnosis of prostate cancer , and there was no increase in the incidence of complications . psad is used to increase diagnostic accuracy in patients who have gray - zone psa values ( 4 - 10 ng / ml ) . some investigators have proposed that prostate biopsy is indicated for patients with a psad value of 0.15 , and others have advocated that the criteria should be lowered . gohji et al reported that in a study of 287 patients with a psa level of 2.1 - 10.0 ng / ml , the psa level had a sensitivity of 90% , a specificity of 36% , and a positive predictive value of 14% in those with a psad value of < 0.12 . a recent study showed that in patients with a psa level of 4 - 10 ng / ml , the psa level had a sensitivity of 90% and a specificity of 33.7% at a psad cutoff value of 0.134 . in our study , combined tpnb and turp was performed on patients with a psa level of 4 - 10 ng / ml as well as a psad value of < 0.12 . as a result , 6 patients ( 14.6% ) were definitively diagnosed with prostate cancer . prostate cancer was diagnosed in 2 patients ( 4.9 ) by tpnb alone , 3 patients ( 7.3% ) by turp alone , and 1 patient ( 2.4% ) by combined tpnb and turp . this result suggests that the diagnostic accuracy of tpnb alone is 7.3% in patients with a psad value of < 0.12 . it is generally recognized that turp is effective in diagnosing prostate cancer in patients with negative tpnb results . of the 6 patients diagnosed with prostate cancer , prostate cancer was definitively diagnosed by turp in 4 patients , 3 of whom were diagnosed by turp alone . in other words , if tpnb alone had been performed on the aforementioned 3 patients , the results might have been negative and the patients might have needed to undergo repeated tpnb or turp . on the basis of these findings , we can infer that combined tpnb and turp may be more effective than repeated tpnb in the diagnosis of prostate cancer in patients with previous tpnb - negative results . the normal range of psa has been reported to be 2.4 - 3.5 ng / ml in the 50 to 59 year group , 3.6 - 5.4 ng / ml in the 60 to 69 year group , and 5.2 - 7.5 ng / ml in the 70 to 79 year group [ 21 - 24 ] . therefore , it is estimated that in elderly patients , the diagnostic accuracy of the psa level may decrease in patients with low psad values . meshref et al reported that the diagnostic accuracy of the psa level in patients with a psa level of 4.1 - 10 ng / ml was 0% in the 50 to 59 year group , 4.1% in the 60 to 69 year group , and 0% in the 70 to 79 year group at a psad cutoff value of 0.15 or less . they also reported that the diagnostic accuracies of the psa level were 4.2% , 1.5% , and 0% , respectively after adjustment for age ( 3.6 - 10 ng / ml for the 50 to 59 year group , 4.6 - 10 ng / ml for the 60 to 69 year group , and 6.6 - 10 ng / ml for the 70 to 79 year group ) . those authors concluded that the diagnostic accuracy of the psa level was 0% at a psad cutoff value of 0.15 or less in the 70 years age group . kobayashi et al showed that diagnostic accuracy is low in patients aged 70 years with large prostate volumes . thus , because the increased psa level is probably due to bph in the 70 years age group , prostate biopsy should be avoided in patients aged 70 years with large prostate volumes . similarly , we found that the diagnostic accuracy of the psa level was 25% and 8% , respectively , for the age groups of < 70 and 70 years . because there is a high possibility of the presence of diabetes mellitus or use of anticoagulant medications , the incidence of complications after tpnb may be high . in bph patients aged 70 years who are scheduled for turp because they have a psa level within the gray zone , separate tpnb can be avoided by performing combined tpnb and turp . first , it was retrospective in nature and the number of subjects was relatively small . second , even though turp can enhance the diagnostic yield of prostate cancer in this group of patients , at the same time it could miss some chances of radical prostatectomy without prior turp . however , we confirmed that combined tpnb and turp is safe and that the possibility of prostate cancer may be reduced in elderly patients as found in previous studies . because combined tpnb and turp is a safe procedure , it should be performed on patients who need the 2 procedures . in particular , this combined procedure may be useful for patients with tpnb - negative results who need turp . moreover , because there is a low possibility of prostate cancer in bph patients with a psad value of < 0.12 and aged more than 70 years old , combined tpnb and turp can prevent unnecessary tpnb before turp .