A new parameter in decision making for transurethral electroresection of benign prostate hyperplasia

OBJECTIVE: In this study, the clinical usefulness of transition zone (TZ) volume (TZV) measured by transrectal ultrasonography (TRUS) was investigated as a new parameter for the preoperative prediction of the treatment efficacy of transurethral resection of the prostate (TURP). METHODS: Fifty-six men with symptomatic benign prostatic hyperplasia (BPH; age 68.6 +/- 9.7 years) underwent TURP and were evaluated based on ordinary BPH parameters such as the international prostatic symptom score (I-PSS), quality of life (QOL) score, peak urine flow and entire prostate volume (PV), as well as the new TZV parameters and calculation of the TZ index. Relative risks were adjusted simultaneously for potentially confounding variables by multiple logistic regression analysis after adjustment for age, QOL, I-PSS, Qmax and residual urine. RESULTS: The adjusted relative risk for TURP at a TZ index of 0.1 increased to 4.5 (95% confidence interval 2.3-8.78). In general, poor responses were observed in patients with less symptomatic scores or lower values prior to operation, but there was a weak correlation between treatment outcome and preoperative scores or values of ordinary parameters. The volume parameters of BPH and PV did not predict treatment efficacy preoperatively, but TZV and the TZ index correlated with the treatment efficacy of TURP. CONCLUSION: TZV and the TZ index seem to be useful new parameters in preoperative decision-making with regard to TURP.     

Transurethral resection or incision of the prostate and other therapies: a survey of treatments for benign prostatic obstruction in the UK.

OBJECTIVE: To establish the current usage of transurethral incision of the prostate (TUIP) and other forms of treatment for benign prostatic obstruction (BPO). METHODS: The Prostate Trial Office (PROTO) sent a survey questionnaire to all 376 consultant urologists in the UK which asked for estimates of their clinical practice in treating BPO. The survey had three principle aims: to assess the role that the determination of prostate size has in clinical practice, to determine the nature and frequency of use of a range of therapies including TUIP, and to examine the feasibility of conducting a randomized controlled trial comparing transurethral resection of the prostate (TURP) and TUIP. RESULTS: Of the 376 urologists, 349 replied (response rate 93%); most respondents used prostate size as a determinant when deciding on therapy for BPO (60%). Of their patients with BPO who were treated, 38% received surgical treatment, 33% drug therapies and 29% conservative management. Of the types of surgical treatment, the most commonly used procedure was TURP, in 79% of patients, with only 15% undergoing TUIP. When compared with TURP, TUIP tended to be used for patients with a mean prostate volume of 相似文献   

Transurethral incision versus transurethral resection of the prostate. A subjective and objective analysis.

A prospective study was undertaken comparing transurethral incision of the prostate (TUIP) with transurethral resection (TURP) in the treatment of 220 patients with urinary obstruction caused by a small, benign prostate. Patients were managed alternately by TUIP and TURP, and their symptoms and urodynamic findings evaluated before and after surgery. Subjectively and objectively, the results were comparable in both groups. Pre- and post-operative complications were significantly less for the TUIPs than the TURPs. TUIP was significantly better than TURP in terms of shorter operating time, duration of hospitalisation and reduced need for transfusion. We recommend TUIP as the operation of choice for the relief of obstruction in the presence of a small, benign prostatic enlargement.     

Volume determinations of the whole prostate and of the adenoma by transrectal ultrasound: correlation with surgical specimen

ObjectiveWe evaluated whether preoperative transrecta ultrasound (TRUS) mesaurements of the transition zone (TZ) and total prostate volumen predict real prostatic weight.Material y MethodsWe compare estimated TRUS volumes with surgical specimen weight, in surgically treated patients with localized prostate cancer (group A, n=33) or benign prostatic hyperplasia (group B, n=37). The volume was calculated by the ellipsoid formula. Both measurements were compared with surgical specimen weight, assuming 1 as specific prostate weight.ResultsGroup A: mean prostate measured volume was 38,6 cc. (SD 22,7), mean RP specimen weight was 54,2 g (SD 27,2)(p=0,001). Total estimated prostate volume underestimated prostatectomy specimen weight by 29%. In order to adequate the estimated volume to the specimen weight, we calculated the formula: estimated prostate weight=0,95 x prostatic measured volume + 17,657 (p=0,005).Group B: mean TZ measured volume was 62,8 cc. (SD 23,3), mean adenomectomy specimen weight was 79,9 g (SD 45,9) (p=0,001). TZ estimated volume underestimated adenomectomy specimen weight by 21%. In order to adequate the estimated volume to the specimen weight, we calculated the formula: estimated TZ weight=1,67 x TZ measured volume - 24,768 (p=0,04).ConclusionsWe found significative differences between TRUS measured volumes and real weight of surgical specimen. These differences could be corrected by simple formulas that allow to minimize the observed underestimations.     

Transurethral incision versus transurethral resection of the prostate in small prostatic adenoma: Long-term follow-up

ObjectivesTo evaluate the efficacy of transurethral incision of the prostate (TUIP) compared to transurethral resection of the prostate (TURP) in patients with small benign prostate adenoma, based on long-term follow-up.Patients and methodsWe prospectively randomized 86 men with bladder outlet obstruction symptoms caused by a prostate less than 30 g to undergo TUIP or TURP. The following preoperative parameters were evaluated: prostate weight, international prostate symptom score (IPSS), voided volume, maximum flow rate (Qmax) and post-void residual volume (PVR). Postoperatively the patients were followed up for 48 months and the following data were collected: morbidity, operative time, catheterization period, hospital stay, Qmax, IPSS, voided volume, PVR and reoperation rate.ResultsA total of 80 of the 86 patients completed the study: 40 patients in each group. The mean age of patients in group I (TURP) and group II (TUIP) was 63.6 and 66.2 years, respectively. Preoperative parameters in both groups showed no statistically significant differences with regard to uroflow parameters and prostate weight. At 48 months follow-up the mean voided volume increased from 161 ml to 356 ml in group I and from 161 ml to 341 ml in group II, Q-max increased from 8.4 to 18.4 in group I and 8.4 to 16.6 in group II, the IPSS decreased from 19 to 5.8 in group I and from 19 to 6.3 in group II and PVR decreased from 107 ml to 20 ml in Group I and from 109 ml to 21 ml in Group II (all differences statistically significant). Comparing groups I and II there were statistically significant differences with regard to mean operative time (60.0 versus 20.6 min), duration of catheterization (3.2 versus 2.2 days), hospital stay (3.7 versus 2.6 days), and the incidence of postoperative retrograde ejaculation (52.5% versus 22.5%) and erectile dysfunction (20% versus 7.5%).ConclusionTUIP and TURP for small prostatic adenoma of less than 30 g are equally effective in providing symptomatic improvement. TUIP is more advantageous with to side-effects, operative time, hospital stay and the duration of catheterization.     

Visual Laser Ablation of the Prostate and Transurethral Resection of the Prostate for Benign Prostatic Hyperplasia

For the past 50 years, transurethral resection of the prostate (TURP) has been the most common treatment for benign prostatic hyperplasia (BPH). The authors have conducted visual laser ablation of the prostate (VLAP) for BPH as a minimum invasive surgery. The results were compared with those of VLAP, VLAP+transurethral incision of the prostate (TUIP), and TURP as other treatments for BPH. In the VLAP group, 50 of 52 (96.2%), 36 of 40 (90.0%) and 31 of 36 (86.1%) were categorized as having more than a Fair Response (FR) at 3, 6 and 12 months, postoperatively. In the VLAP+TUIP group, 24 of 29 (82.8%), 19 of 22 (86.4%) and 9 of 11 (81.8%) were classed as having more than a FR at 3, 6 and 1 2 months, postoperatively. Forty–one of 42 (97.6%), 1 7 of 1 7 (100.0%) and 6 of 6 (100.0%) patients reaction to TURP was more than FR in overall response at 3, 6 and 12 months, postoperatively. The need for a blood transfusion, perforation of the prostate capsule and transit incontinence persisting for more than 1 month occurred in 1 of 45 (2.2%), 1 (2.2%) and 4 (8.9%) patients in the TURP group. Bladder neck contracture was seen in 4 of 52 (7.7%) in the VLAP group. Average postoperative catheter duration was shorter in the VLAP+TUIP (5.7 ± 8.4 days) than in the VLAP group (10.3 ± 10.4 days). Although TURP remains the standard treatment for BPH, VLAP results in less morbidity compared to TURP. VLAP with TUIP appears to lessen the risk of postoperative urinary retention and provide better results in longer follow–up studies.     

Transurethral resection versus transurethral incision of the prostate. A prospective randomized study

In this ongoing study, patients with an estimated prostate size of no more than 20 gm are randomized to undergo either transurethral resection of the prostate (TURP) or transurethral incision (TUIP) at the 6 o'clock position. To date, 93 patients have been included, and 3 months postoperatively, 80 to 90 per cent of the patients in each group reported improvement. There was also a significant decrease in symptom scores and a significant increase in maximum urinary flow rate, with great variation within each group but without difference between the groups. In both groups, there appears to be some deterioration over time. Operating time, estimated blood loss, time to catheter removal postoperatively, and duration of postoperative hospital stay were all significantly in favor of TUIP. Loss of ejaculation was reported by 37 per cent of patients after TURP and by 13 per cent after TUIP (not statistically significant). There was no difference between the groups in the need for further surgery. Therefore, TUIP is recommended as an alternative to TURP in patients with small prostates.     

Comparison of long-term results of transurethral incision of the prostate with transurethral resection of the prostate, in patients with benign prostatic hypertrophy

One hundred patients with benign prostatic hypertrophy (BPH) were randomized to transurethral incision (TUIP) or transurethral resection of the prostate (TURP). The average prostate weight before operation was not more than 30.0 g. Indications for the operations were based on the disease history, physical examination, digital rectal examination, laboratory values, and pressure-flow examination. All operations were performed with patients under spinal anesthesia. TUIP was performed with a Collins knife, and TURP was performed with a resectoscope. Follow-up was performed 24 months after the operations. After treatment there were statistically significant daytime and nocturnal reduction in voiding frequencies of 2.9 and 1.7, respectively, after TUIP, and 2.0 and 1.5 after TURP. In both groups, there occurred significantly better maximal flow rate from 7.6 mL/s to 16.9 mL/s in group I and from 6.9 mL/s to 17.6 mL/s in group II. The mean values of linearized passive urethral resistance relation in both groups significantly decreased from 3.6 +/- 0.6 to 1.0 +/- 0.5 after TUIP and from 3.9 +/- 04 to 1.4 +/- 0.5 after TURP. The TUIP procedure is effective and safe for patients with a small number of complications.     

Transurethral interstitial laser coagulation of the prostate and transurethral microwave thermotherapy vs transurethral resection or incision of the prostate: results of a randomized,controlled study in patients with symptomatic benign prostatic hyperplasia

OBJECTIVE: To compare the efficacy and frequency of complications of transurethral interstitial laser coagulation (ILC) and transurethral microwave thermotherapy (TUMT) with transurethral resection or incision of the prostate (TURP/TUIP) in patients with symptomatic benign prostatic hyperplasia (BPH). PATIENTS AND METHODS: Forty-eight patients were randomized to undergo ILC, 46 to TUMT and 24 to TURP/TUIP; they were followed for 6 months and the outcome analysed on an intention-to-treat basis. RESULTS: At 6 months the symptom scores and maximum urinary flow rate (Qmax) had improved significantly in all groups. At 6 months the mean symptom score was 9.2 in both experimental groups and 6.8 in the control group (P > 0.05); the mean Qmax was 20.6 mL/s in the control group, 16.2 in the ILC group (P > 0.05 vs control) and 13.2 in the TUMT group (P < 0.05 vs. the control group). In the TUMT group patients developing urinary retention afterward had a significantly greater increase in Qmax than those who did not. The types of complications in the three groups varied. Urinary tract infection occurred frequently in the experimental groups, especially after ILC, whereas the 'well-known' complications of TURP occurred in the control group. Overall, 36% in the ILC, 54% in the TUMT and 73% in the control group had no complications (retrograde ejaculation excluded) during the first 6 months. One patient in the TUMT group underwent TURP after 3 months, whereas no patients in the ILC or the con-trol group were re-treated for BPH within the first 6 months. CONCLUSION: In the short term both ILC and TUMT are reasonable alternatives to standard transurethral surgery for symptomatic BPH, where the reduction of symptoms is the primary goal of treatment. However, both ILC and TUMT were associated with morbidity, although the complication profiles differed from those after TURP/TUIP. Both ILC and TUMT seem advantageous in some patients because of the reduced risk of bleeding and the eliminated risk of TUR syndrome, and because TUMT only requires local anaesthesia. Thus, as neither treatment is better in all aspects, the advantages of one technique over the other must be weighed when deciding how to treat each patient.     

The correlation between clinical outcome and residual prostatic weight ratio after transurethral resection of the prostate for benign prostatic hyperplasia

OBJECTIVE: To assess in a prospective study the use of a new variable, the residual prostatic weight ratio (RPWR), for evaluating the clinical outcome after transurethral resection of the prostate (TURP). PATIENTS AND METHODS: From April 1996 to June 1997, 40 men (mean age 70.4 years, range 53-85) with symptomatic benign prostatic hyperplasia were evaluated using the American Urological Association (AUA) symptom score, measurements of the mean and maximum urinary flow rate (Qave and Qmax), and by transrectal ultrasonography (TRUS) before and 16 weeks after TURP. The estimated total prostate weight was derived as 0.52 x length x width x height x the specific gravity of the prostate (1.010). The RPWR was calculated as the prostate weight after TURP divided by the initial weight, where the value after TURP was the initial weight minus that of the TURP specimen. The clinical outcome was evaluated by the difference (Delta) in AUA score, Qmax and Qave before and 16 weeks after surgery. RESULTS: There was a close correlation between the estimated prostate weight and the actual weight of the TURP specimen (r = 0.82 and 0.80 for the adenoma and total prostate, respectively). The mean (SD) RPWR, DeltaAUA score, DeltaQmax and DeltaQave were 50.1 (17.1)%, 11.5 (5. 3), 9.0 (4.2) mL/s and 6.2 (2.9) mL/s, respectively. There was a negative correlation between the RPWR and the DeltaAUA, DeltaQmax and DeltaQave (r = -0.81, -0.68, and -0.70, respectively, P < 0.05). The prostate volume estimated by TRUS decreased significantly 16 weeks after TURP. CONCLUSIONS: TRUS is a useful tool for estimating prostate weight before surgery. The smaller the RPWR at 16 weeks after TURP, the better the clinical outcome.     

Three-dimensional ultrasonography in evaluation of benign prostatic hyperplasia

BACKGROUND: The clinical application of volume estimation by 3-D ultrasound has recently gained much attention. However, there have been no reports evaluating the prostate volume by 3-D transrectal ultrasound (TRUS) before transurethral resection of the prostate (TURP). The purpose of the present study was to evaluate the value of 3-D TRUS for prediction of prostate morphology and resected weight before TURP and to investigate whether 3-D TRUS is a more useful examination than 2D TRUS in patients with benign prostatic hyperplasia (BPH). METHODS: Transurethral resection of the prostate was performed in 23 patients with BPH. We evaluated the prostate morphology and measured both the volumes of the whole prostate and the transition zone using 2-D and 3-D TRUS, respectively. The actual resected weight was recorded and compared with the volume of the whole prostate and that of the transition zone measured by 2D and 3-D TRUS. RESULTS: The volume of the transition zone measured by 3-D TRUS correlated most strongly with the resected weight (r = 0.84). A large median lobe was seen in three patients in whom the transition zone volume measured by 2-D TRUS was considerably larger than the resected weight. However, overestimation in the three patients decreased by the use of 3-D TRUS. CONCLUSIONS: It was concluded that 3-D TRUS was equal or superior to 2-D TRUS in prediction of the resected weight and 3-D TRUS offers better information as a diagnostic tool before TURP.     

Operative und instrumentelle Therapie bei BPH/BPS

In recent decades, several various interventional procedures for the treatment of symptomatic benign prostatic hyperplasia (BPH) have been developed. Most of them were considered potential alternatives to prostatic surgery such as open prostatectomy, transurethral resection of the prostate (TURP), or transurethral incision of the prostate (TUIP). Despite good results observed in the initial clinical studies, most concepts and procedures were never generally accepted. However, they contributed considerably to general knowledge regarding the treatment of symptomatic and obstructive BPH. Only a few procedures could stand the test of time and became part of the urological armamentarium. Currently, interventional therapies are classified by their effects on prostate tissue: procedures with immediate tissue ablation (open prostatectomy, TURP, vaporization techniques, laser resection techniques), thermal coagulating procedures with delayed tissue ablation (transurethral high-energy microwave thermotherapy, transurethral needle ablation, interstitial laser coagulation), and other procedures (TUIP, stents) with deobstruction effects without tissue ablation. The analysis of clinical studies shows a great variety of different results. The main reason for this fact is that the design of past and present studies ignored the pathophysiological aspects of BPS, especially the obstructive component, and the fact that the outcome of most procedures more or less depends on the operator/user.     

The importance of measuring the prostatic transition zone: an anatomical and radiological study.

OBJECTIVE: To assess the accuracy and reliability of measurements of the volume of the transition zone (TZ, representing the hypertrophied benign component) and whole prostate by TRUS in patients with BPH or cancer, by comparing the radiological with pathological findings after surgery. PATIENTS AND METHODS: The study comprised 36 patients with prostate cancer undergoing radical prostatectomy and 34 patients with symptomatic BPH treated using retropubic adenectomy. The weights of the radical prostatectomy specimens and of the enucleated adenomas were correlated with the corresponding volumes of the TZ and of the whole prostate, respectively, measured by TRUS using the prolate ellipsoid method. RESULTS: The mean (sd) TZ volume measured by TRUS was 36.9 (25.48) mL, whereas the weight of the enucleated specimen was 42.7 (33.58) g (correlation coefficient r=0.95, P<0.001). The TRUS estimate of the volume of the whole prostate was 29.2 (9.24) mL, while the radical prostatectomy specimens weighed 34.5 (10.76) g (r=0.78, P<0.001). The variability in the TZ volume estimate ranged from -17% to +18%, whereas the variability for whole prostate was -21% to +30% (P<0.05). CONCLUSIONS: Measurements of the TZ of the prostate by TRUS are more accurate than those for the whole prostate. An assessment of the TZ volume may be sufficiently reliable to be used in the clinical management of BPH and to detect prostate cancer using the prostate-specific antigen density of the TZ as a marker.     

Measurement of residual adenoma after transurethral resection of the prostate by transurethral enucleation technique

OBJECTIVE: Transurethral resection of the prostate (TURP) leaves a lot of residual adenoma and has a high recurrence rate, but the residual adenoma weight has not been measured surgically. Using surgery we tried to measure the residual adenoma after TURP. MATERIAL AND METHODS: Total adenoma resection was performed via standard TURP in 64 cases with benign prostatic hyperplasia and the weight of the residual adenoma was measured by transurethral enucleation (TUE) of the prostate. RESULTS: Prostate volume averaged 37.4 ml and adenoma volume averaged 20.6 ml by TRUS. The average weight of the prostate removed by TURP was 9.8 g. After TURP residual adenoma was confirmed in all cases by TUE, and the average weight of the residual adenoma was 10.2 g. The total average prostate volume removed by TURP and TUE was 20.1 g. The average residual rate of the adenoma removed by TURP was 54.5%. CONCLUSION: TURP leaves about half of the adenoma. Therefore, TURP might be very difficult for complete resection of an adenoma.     

Transition zone index in predicting therapeutic efficacy of benign prostatic hyperplasia

PURPOSE: We studied how transition zone index (TZ index) influenced the therapeutic efficacy of benign prostatic hyperplasia (BPH). In addition, we retrospectively investigated the availability of TZ index in selection of the more effective therapeutic method for BPH. METHOD: One hundred twenty-five patients with symptomatic BPH whose prostate volume (PV) was more than 15 ml by transrectal ultrasonography were investigated. Sixty-nine men underwent transurethral resection of the prostate (TURP) whereas 56 were treated with alpha 1-blocker. Tamsulosin hydrochloride. These patients were evaluated based on TZ index as well as ordinary parameters of BPH; international prostatic symptom score, QOL score, peak flow rate and PV. RESULTS: The patients with TZ index > or = 0.5 showed good therapeutic results in the TURP group. On the other hand, the patients with TZ index < 0.5 showed favorable response in alpha 1-blocker group. Multivariate analysis revealed that TZ index affected the therapeutic efficacy more strongly than the other parameters. CONCLUSION: TZ index had strong influence on therapeutic efficacy of TURP or alpha 1-blocker and seemed to be a useful tool for the selection of BPH therapy.     

Transurethral incision of the prostate and bladder neck.

Transurethral incision of the prostate (TUIP) is compared to transurethral resection of the prostate (TURP) by reviewing nonrandomized, matched, and randomized studies. These studies indicate that incision of the prostate and bladder neck relieves outflow urinary obstruction, as does TURP. The incision is relatively easier to learn and perform, and requires shorter operative time compared to TURP. The incidence of retrograde ejaculation is lower after incision than after TURP--16% versus 63%, on average. Transurethral incision of the prostate has a potential for reduced costs due to reduced operative time, shortened hospital stay, and the potential for local anesthesia.     

Does transurethral resection of the prostate facilitate detection of clinically significant prostate cancer that is missed with systematic sextant and transition zone biopsies?

BACKGROUND: A prospective study was conducted to determine whether transurethral resection of the prostate (TURP) facilitates detection of prostate cancer that is missed with systematic sextant biopsies associated with transition zone (TZ) biopsies. METHODS: A total of 139 consecutive patients underwent transperineal TZ biopsies of each lobe in addition to a transrectal systematic sextant peripheral zone (PZ) biopsy. Patients whose biopsies were negative for cancer received TURP for relief of lower urinary tract obstruction when indicated. RESULTS: Cancer was detected in biopsy specimens of 40 patients. Of these cancers, 18 originated in the PZ alone and 22 were located both in the TZ and the PZ. No cancers were detected in the TZ alone. Of 99 patients who were proven not to have cancer by the biopsies, 18 were indicated for TURP. Five of these patients (28%) had cancer in the resected tissues. All cancers were clinically organ confined and their Gleason sum scores were 2-5. Cancer-positive chips accounted for less than 10% of all resected specimens. Of the 66 patients with negative biopsies and without indication for TURP, four (6%) were revealed to have an elevation of the serum PSA level during follow up. They were later proven to have cancer by a second biopsy. CONCLUSION: Routine use of TZ biopsy is not warranted for detection of cancer. Transurethral resection of the prostate can detect cancers in patients with negative PZ and TZ biopsies. However, cancers detected by TURP may not always be clinically significant and only four of 66 patients who were not indicated for TURP and received a close follow up were later found to have cancer, although their follow-up period was short. Thus, it still remains to be elucidated whether TURP is necessary for all patients with negative biopsies of the prostate.     

The clinical effectiveness of transurethral incision of the prostate: a systematic review of randomised controlled trials

Purpose  

Transurethral incision of the prostate gland (TUIP) is perceived as a less morbid surgical alternative to standard transurethral resection of the prostate gland (TURP) for treatment of symptomatic mild to moderate benign prostate enlargement (BPE). We aimed to evaluate comparative clinical effectiveness of the two procedures.     

Importance of TURP in diagnosing prostate cancer in men with multiple negative biopsies

OBJECTIVE: Patients with persistently elevated PSA and multiple negative TRUS guided 12-core biopsies, present a clinical conundrum. We evaluated the efficacy of transurethral biopsy and/or resection in abetting prostate cancer diagnosis. PATIENTS AND METHODS: Eleven patients who had prostate cancer diagnosed only on TURP following TRUS guided (24-48 cores) negative biopsies, including five who underwent radical prostatectomy were assessed. Extent and site of tumour was analysed in relation to the TURP cavity. RESULTS: Mean age was 61.8 years (PSA range: 3.8-20.9 ng/ml.). Patients had TURP for worsening LUTS with chippings diagnosing invasive prostate cancer. Organ confined anterior prostate cancer was diagnosed in five who had radical prostatectomy. CONCLUSION: Anteriorly directed transurethral biopsies and/or TURP help in the diagnosis of prostate cancer in patients with multiple negative biopsies. Patients with anterior prostate cancer tend to have organ-confined disease even with higher PSA.     

Relationship between clinical stage and histological zone of origin in early prostate cancer: morphometric analysis.

A detailed morphometric analysis of 96 radical prostatectomy specimens (13 clinical stage A1, 29 A2, 34 B1 and 20 B2) was undertaken to examine the relationship of zone of origin to volume, grade and extraprostatic extension of cancer. In patients with stage A disease, transition zone (TZ) cancer (present in 81%) was significantly larger but of lower grade than peripheral zone (PZ) cancer (present in 90%). The total volume of cancer in stage A1 patients averaged 1.55 ml with 72% of TZ origin. In patients with stage A2 disease, tumour volume averaged 5.83 ml with only 57% of TZ origin. Specimens taken during transurethral resection of the prostate (TURP) revealed TZ cancer in 82% and PZ cancer either alone or with TZ cancer in 22%. The 9 patients with PZ cancer in the TURP specimen included 5 of the 11 with extracapsular extension and all 5 of those with seminal vesicle invasion. Every patient with stage B disease had PZ cancer which, in all except 3 cases, was of significantly larger volume and higher grade than any TZ cancer (present in 43%) in the same gland. In patients with stage B cancer, total tumour volume was 5.13 ml with 91% of PZ origin. TZ cancer tended to be well differentiated in all patients, even at large volumes, whereas PZ cancer was often moderately or poorly differentiated even at low volumes. In patients with stage B disease, TZ cancer appeared to be incidental and of no clinical importance, while in stage A patients PZ cancers were sometimes large, poorly differentiated and extended outside the prostate. Progression of a stage A cancer seems more likely to result from PZ cancer than TZ cancer, and the finding of PZ cancer in a TURP specimen should probably preclude its classification as stage A1.