Delivery of replication-competent retrovirus expressing Escherichia coli purine nucleoside phosphorylase increases the metabolism of the prodrug, fludarabine phosphate and suppresses the growth of bladder tumor xenografts

We have developed unique replication-competent retroviral (RCR) vectors based on murine leukemia virus that provide improved efficiency of viral delivery, allow for long-term transgene expression and demonstrate an intrinsic selectivity for transduction of rapidly dividing tumor cells. The purpose of this study was to evaluate the in vivo transduction efficiency and the therapeutic efficacy of the RCR vector mediated delivery of Escherichia coli purine nucleoside phosphorylase (PNP) in combination with fludarabine phosphate for bladder cancer. We constructed vectors containing green fluorescent protein (GFP) gene (ACE)-GFP) or PNP gene (ACE-PNP). KU-19-19 bladder tumors exhibited 28.3+/-16.1, 46.6+/-5.8 and 93.7+/-7.8% of GFP expression on 14, 18 and 26 days after intratumoral injection of ACE-GFP, respectively. GFP expression could not be observed in normal tissues surrounding the injected tumors. No detectable polymerase chain reaction products of GFP gene could be observed in any distant organs. Intratumoral injection of ACE-PNP, followed by systemically administered fludarabine phosphate, significantly inhibited the growth of pre-established KU-19-19 tumors. Our results indicate that RCR vectors are a potentially efficient gene delivery method and that the RCR vector mediated PNP gene transfer and fludarabine phosphate treatment might be a novel and potentially therapeutic modality for bladder cancer.

Incidence, location, and significance of periprostatic and periseminal vesicle lymph nodes in prostate cancer

Pelvic lymph node metastases in prostate cancer (PCa) carry an ominous prognosis. Periprostatic/periseminal vesicle (PP/PSV) lymph nodes are present in some individuals, but their incidence and involvement by metastases are unknown. A total of 832 of 1233 (67.5%) patients who underwent radical retropubic prostatectomy for clinically localized PCa at the Methodist Hospital from 1983 to 1998 by one surgeon (P.T.S.) had whole-mount slides available for review. Of these, 92 (11.1%) had received preoperative therapy (radiation in 48 [5.8%], hormonal in 44 [5.3%]). Slides were examined with the naked eye by placing them on a white illuminated background, and any area suggestive of a lymph node in PP/PSV fat was confirmed microscopically and assessed for the presence of metastases. Thirty-seven of 832 patients (4.4%) had 39 PP/PSV lymph nodes-one bilateral, one with two ipsilateral lymph nodes, and the rest solitary. Sizes ranged from 0.7 to 4.5 mm (mean 1.8 mm). Distribution was 2 of 39 (5.1%) apical, 3 of 39 (7.7%) mid, 17 of 39 (43.6%) base, and 17 of 39 (43.6%) seminal vesicle. Five patients (0.6%) had metastatic PCa to the PP/PSV lymph nodes. All five patients were of advanced pathologic T stage [one pT3a (extraprostatic extension) and four pT3b (seminal vesicle invasion)]. Only two of those five (40%) had metastases (all ipsilateral) to pelvic lymph nodes. In three of five (60%) the metastases were isolated to the PP/PSV lymph nodes. Metastases were to the lymph nodes in the periseminal vesicle fat in four of five (80%) of the cases and in the fat surrounding the base of the prostate in one of five (20%). Four of five (80%) patients recurred. Histologic grade (Gleason score), tumor volume, and failure (recurrence) rates were significantly different between the five patients with metastases and the 32 patients without metastases to the PP/PSV lymph nodes (p <0.0001, p <0.0001, and p = 0.005, respectively). However, there was no evidence that an individual patient's probability of having a PP/PSV lymph node increased with resection of the neurovascular bundle (p = 0.7698). PP/PSV lymph nodes are uncommon, but based upon these limited data, it appears that patients with metastases limited to PP/PSV lymph nodes have a poor prognosis (similar to pelvic lymph node metastases) and should be included in the American Joint Committee on Cancer (AJCC) Staging Manual to indicate "N1" if positive for metastases.

Prognostic significance of the diameter of perineural invasion in radical prostatectomy specimens

We assessed whether the quantification of cancer invasion into the perineural space influences the prognosis of patients treated with radical prostatectomy. We conducted a retrospective study of clinical and pathologic features in 640 consecutive patients with clinical stage Tla-T3bNXM0 prostate cancer who were treated with radical retropubic prostatectomy by the same surgeon between 1989 and 1995. None had received preoperative hormonal therapy or radiotherapy. Detailed pathologic analysis, including the presence and maximum diameter of perineural invasion (PNI), was performed by 2 pathologists. Treatment failure was defined as either a serum prostate-specific antigen (PSA) level > 0.4 ng/mL and rising or initiation of adjuvant therapy. The median follow-up time was 48 months (range, 1 to 111 months). Overall, PNI was detected in 477 patients (75%). The progression-free 5-year probability rate after prostatectomy for patients with PNI was 70% +/- 3% compared with 94% +/- 2% for patients without PNI (P <.001). The mere presence of PNI was not an independent predictor of progression in a Cox proportional hazards analysis when the other established prognostic factors (serum PSA level, pathologic stage, surgical margin, and tumor volume) were considered. However, the increasing diameter of the largest focus of PNI was strongly associated with other established prognostic factors and the probability of progression after radical prostatectomy. Although little adverse effect in patients with PNI < 0.25 mm was seen 5 years after surgery, those with a PNI diameter of 0.25 to 0.5 mm were significantly (P <.001) less likely to remain free of progression; only 36% of those with PNI of 0.5 to 0.75 mm (P <.001) and 14% of those with PNI > or =0.75 mm (P =.002) were free of progression. In a Cox proportional hazard analysis, the PNI diameter was an independent predictor of prognosis. These results support that the measurement of the PNI diameter, easily recorded from prostatectomy specimens, could add important information to the prognosis of prostate cancer patients. Controversy regarding the significance of PNI may result from the lack of quantitative assessment of PNI in previous studies.

[Minimally invasive therapy for bladder and prostate cancer]

Recently, minimally invasive therapy has been a key word in the medical field. Many new therapies have been developed in the field of urology. In this area, bacillus Calmette-Guerin (BCG) instillation therapy, transurethral resection of the bladder tumor and intra-arterial infusion with irradiation therapy are noted as minimally invasive therapies for bladder cancer. Laparoscopic prostatectomy, brachytherapy, three-dimensional conformal radiotherapy (3D-CRT) and high-intensity focused ultrasound (HIFU) have also been developed as minimally invasive therapies for prostate cancer. Though the establishment of the validity of each treatment will still take time, the best treatment for each patient should be chosen case by case, including considerations of postoperative quality of life and economic efficiency.

Primary Gleason pattern as a predictor of disease progression in gleason score 7 prostate cancer: a multivariate analysis of 823 men treated with radical prostatectomy

Gleason score (GS) is a powerful predictor of disease progression in men with prostate cancer (PCa). The majority of clinically localized prostate cancers, however, are moderately (GS5/6) or moderate to poorly (GS7) differentiated tumors with indeterminate prognosis. Differences in disease progression between patients with GS5/6 and GS7 tumors suggest the presence of any component of high-grade tumor (Gleason pattern [GP] 4/5) worsens prognosis markedly. Indeed, McNeal et al. have shown that quantification of GP4/5 provides prognostic information beyond the standard GS. Few investigators have analyzed whether primary and secondary GPs are important prognostically within GS7 PCa. All 823 whole-mount radical prostatectomy specimens with GS7 from a single surgeon (P.T.S.) were analyzed. Tumors were either 3+4 or 4+3, and primary GP was assigned by the same pathologist (T.M.W.). A total of 643 patients with 3+4 tumors and 180 patients with 4+3 tumors were studied. Statistical analysis using the log-rank test showed a significant difference in recurrence-free survival between patients with primary GP4 and those with GP3 (p <0.0001). However, in multivariate analysis with preoperative prostate-specific antigen, total tumor volume, surgical margin status, and the presence or absence of seminal vesicle involvement, extraprostatic extension, and lymph node metastasis, the primary GP did not retain independent significance (p = 0.0557). GS7 PCa is a heterogeneous group of tumors. In this cohort of men with GS7 tumors treated by radical retropubic prostatectomy, primary GP showed a significant correlation with other histologic and clinical predictors of disease progression; however, it was not independently predictive of disease progression in multivariate analysis (p = 0.76).

Results of radical prostatectomy in men with locally advanced prostate cancer: multi-institutional pooled analysis

OBJECTIVE

We investigated the disease-specific and metastasis-free survival rates in men with locally advanced (clinical stage T3) prostate cancer who were treated surgically.

METHODS

A retrospective, multi-institutional pooled analysis of the results of surgical treatment in 345 men with clinical stage T3 disease was performed. Survival curves were generated using the Kaplan-Meier method.

RESULTS

Among 298 evaluable patients, pelvic lymphadenectomy alone was performed in 56 men (19%), while 242 men (81%) underwent node dissection and radical prostatectomy. In total, 122 of 298 patients (41%) had nodal metastases and/or seminal vesicle tumor spread. Pathologically organ-confined disease was noted in 27 men (9%). The actuarial 10-year disease-specific and metastasis-free survival rates for all patients managed surgically were 57 and 32%, respectively. For patients with well, moderately and poorly differentiated tumors, cancer-specific survival rates at 10 years were 73, 67 and 29%, respectively.

CONCLUSIONS

A large number of men with clinical stage T3 prostate cancer have advanced disease and are unlikely to achieve improved long-term survival with surgery alone. Although there may be a role for radical prostatectomy in selected patients with low to intermediate grade tumors, such treatment appears unlikely to result in long-term survival in men with high grade disease. A prospective study is necessary to determine the optimal treatment approach in men with locally advanced prostate cancer.

Efficacy and limitations of delayed/salvage radiation therapy after radical prostatectomy

OBJECTIVE

To assess the kinetics of prostate specific antigen (PSA) and the degree of PSA suppression, to better understand the efficacy and limitations of delayed/salvage radiation therapy after radical prostatectomy.

PATIENTS AND METHODS

The PSA doubling time was calculated in patients with biochemical failure after radical prostatectomy and in those who underwent delayed/salvage radiation therapy. Patients in whom PSA was undetectable by conventional assay after irradiation were followed using a hypersensitive PSA assay.

RESULTS

Of 125 patients who underwent radical prostatectomy for clinically resectable prostate cancer, 47 developed biochemical failure at a mean of 11.8 months after surgery; 38 of these patients underwent radiotherapy (36 for isolated biochemical failure and two for local progression with elevated PSA levels). The mean (sd) PSA doubling time after surgery was 14.6 (16.2) months (n=44) and after radiation therapy it was 13.3 (23.9) months (n=32). Eleven of 30 evaluable patients (37%) had a sustained PSA suppression lasting at least 12 months after radiotherapy. Only the time to biochemical failure after surgery approached statistical significance for predicting a durable response to radiotherapy (P=0.08). The mean nadir value of PSA in the 11 patients with at least 12 months of sustained PSA suppression was 0.032 ng/mL at 26.9 months.

CONCLUSIONS

The rapidity with which PSA levels double after surgery may provide a clinically significant indication of the nature of these recurrent tumours, which deserve the best possible attempt at cure. Slow-growing tumours with longer PSA doubling times may be better candidates for delayed/salvage radiation therapy. Larger studies involving more patients are needed to determine whether the PSA doubling time can define subgroups for which specific treatment strategies should be developed.

[Extragonadal seminoma with testicular microlithiasis: a case report]

A 43-year-old men presented with left supraclavicular growing mass. Ultrasonography revealed a 31 x 21 mm solid mass with a homogeneous echoic pattern. Lymph node metastasis of some malignant neoplasms was highly suspected. However, whole body evaluation with computed tomographic scan revealed no findings in the primary region. In addition, tumor markers including alpha fetoprotein, human chorionic gonadotropin and carcinoembryonic antigen were within normal limits. Then, extirpation of supraclavicular mass was performed and pathological diagnosis was made as pure seminoma. Evaluation of testicle by ultrasonography revealed a diffuse calcification. However, histological examination of biopsy specimen of testicle revealed no malignancy. The mass was finally diagnosed as extragonadal or "burned-out" pure seminoma. The patient received two courses of Peplomycin, vinblastine and cisplatin (PVP) therapy, and there has been no evidence of recurrence for 34 months.

Parathyroid hormone-related protein is an independent prognostic factor for renal cell carcinoma

BACKGROUND

Parathyroid hormone-related protein (PTHrP) has been shown to be the principal cause of humoral hypercalcemia associated with renal cell carcinoma (RCC). Recent studies have demonstrated that the amino-terminal region of PTHrP has growth factor-like activities, suggesting it may play a role in the development of RCC. In this study, expression of the carboxy-terminal region of PTHrP was assessed immunohistochemically and its significance in predicting the prognosis of RCC was studied.

METHODS

Forty radical nephrectomy specimens were immunostained with a murine monoclonal antibody (9H7) against the carboxy-terminal region (amino acids 109-141) of PTHrP using the streptavidin-peroxidase enzyme conjugate method. Staining intensity was evaluated semiquantitatively and compared with clinicopathologic features of the corresponding RCC.

RESULTS

Immunoreactivity to 9H7 was observed to be localized to the cytosol of tumor cells at various staining intensities. There were 30 cases (75.0%) with strong staining and 10 cases (25.0%) in which staining was weak or nonexistent. Staining intensity showed no significant correlation with gender, tumor greatest dimension, stage, or grade. Tumors of the clear cell type expressed PTHrP to a significantly greater extent than tumors of the granular cell type. Tumor recurrence was significantly greater in the weakly stained or unstained group compared with the strongly stained group (P = 0.035). Multivariate analysis indicated that PTHrP expression and tumor stage were equally significant prognostic indicators in RCCs measuring <10 cm in greatest dimension.

CONCLUSIONS

Evident PTHrP(109-141) expression is present in the majority of RCCs. The results of the current study indicate PTHrP(109-141) may be a possible marker of cellular differentiation and may be useful for predicting recurrence free survival in RCC patients after radical nephrectomy.

[Histological characteristics and clinical significance of Japanese prostate cancer with low levels of prostate specific antigen of 4.0 ng/ml or lower]

PURPOSE

They set a normal limit of prostate specific antigen (PSA) to 4.0 ng/ml in Tandem R assay at most institutions. We investigated clinical and histological characteristics of prostate cancer based on whole mount step-section histology of radical prostatectomy specimens, and taking notice of Japanese prostate cancer whose levels of PSA are less than 4.0 ng/ml in normal levels.

MATERIALS AND METHODS

One hundred and twenty-two patients underwent radical prostatectomy for clinically resectable prostate cancer at University Hospital from February 1992 to April 1997. Clinicopathological findings were stratified according to the preoperative PSA levels in 111 patients without preoperative endocrine therapy. Immunohistochemical study for PSA was conducted in 7 randomly selected patients.

RESULTS

Of the patients 22 (19.8%) had normal (4.0 ng/ml or lower) preoperative serum PSA. Mean tumor volume in this PSA range was 1.5 cm3 with one pT 0 case included. Pathologically organ confined, potentially curable disease (< pT 3) was found in 17 (77.3%) patients and extracapsular extension and seminal vesicle invasion in 5 (23.8%), respectively. No patients had positive pelvic lymph nodes. Well differentiated tumors of Gleason scores 2-4 were found in 9 (40.9%) of the patients, moderately differentiated tumors (Gleason scores 5, 6) in 5 (22.7%) and poorly differentiated histology (Gleason scores 7-10) in 7 (31.8%). Sixteen (72.7%) patients had clinically significant tumors (> 0.5 cm3, Gleason score > or = 7). All 7 patients had positive staining for PSA, but its intensity did not correlate with serum PSA levels.

CONCLUSIONS

Many prostate cancers found in surgical specimens were clinically significant despite the low levels of PSA and potentially curable by definitive treatment. Age, co-morbidity and other clinicopathological variables as well as PSA levels should all be taken into account when treatment options are discussed.

BRCA1 gene mutation and loss of heterozygosity on chromosome 17q21 in primary prostate cancer

The tumor suppressor gene BRCA1 on chromosome 17q21 has been characterized and shown to be mutated in patients with familial breast and ovarian cancer. Several studies examined the relatives of women with breast cancer and noted an association with ovarian and prostate cancer. This study investigated 24 human prostate cancer specimens for BRCA1 gene mutations and loss of heterozygosity (LOH) on chromosome 17q21 assessed by the polymerase chain reaction. LOH was identified using 7 highly polymorphic tandem repeat markers on chromosome 17q21, in addition to an analysis of the whole coding region of the BRCA1 gene. Four of the 24 prostate cancer specimens showed LOH at one or more loci, all of which were histologically poorly differentiated (4 of 11) and stage D (4 of 15). One of the 24 cases showed a germ-line mutation of the BRCA1 gene, and a sister of this patient died of ovarian cancer. It appears that the BRCA1 gene is not frequently involved in the development of primary prostate cancer.

Pathological features and prognostic significance of prostate cancer in the apical section determined by whole mount histology

PURPOSE

We test the hypothesis that cancer in the apical section of the prostate is an important independent factor in predicting the progression of clinically localized prostate cancer.

MATERIALS AND METHODS

We analyzed clinical data and whole mount histological step sections for 500 patients who had undergone radical retropubic prostatectomy for clinically localized prostate cancer.

RESULTS

Cancer was in the apex of the prostate in 175 patients (35%). These patients had a larger cancer and higher incidence of positive surgical margins, and were more likely to have a poorly differentiated cancer than the 325 patients without cancer in the apex. However, the presence of apical cancer was not a significant predictor of clinical or prostate specific antigen progression in either univariate or multivariate Cox proportional hazards models when analyzed for the entire group or only in patients with tumor confined to the prostate.

CONCLUSIONS

Apical cancer in a radical prostatectomy specimen is simply a sign of a larger volume cancer and is not independently associated with an increased risk of clinical or prostate specific antigen progression.

Factors influencing morbidity in patients undergoing transurethral resection of the prostate

OBJECTIVES

Transurethral resection of the prostate (TURP) has become the primary method to relieve bladder outlet obstruction for patients with benign prostatic hyperplasia (BPH). Data from 3861 consecutive patients with BPH who underwent TURP from 1971 to 1996 at our hospital were retrospectively analyzed.

METHODS

The patients were classified into two groups comprising 1930 patients who underwent TURP from 1971 to 1985 (early group) and 1931 patients who underwent TURP from 1985 to 1996 (late group). Risk factors associated with blood transfusions and perioperative complications were analyzed in these patients.

RESULTS

Mortality, morbidity, and blood transfusions were noted in 5 (0.1 %), 516 (13.4%), and 507 (13.1%) patients, respectively. The blood transfusion and morbidity rates decreased over the 25-year period (P <0.001, chi-square test for trends), which was reflected in a decrease in these rates in the late group (6.1% and 9.5%, respectively) compared with those of the early group (20.2% and 17.2%, respectively). Postoperative bleeding and morbidity were closely related to prostatic gland size and operating time. The most significant differences for the risk of a blood transfusion were related to resection time, the amount of tissue resected, age, and the decade (1970s, 1980s, or 1990s) in which the surgery was performed (P <0.0005), whereas resection time was significantly correlated with morbidity (P <0.0005). As risk factors for each complication, the time of surgical resection, the decade of surgery, and the amount of tissue resected directly correlated with the incidence of extravasation and hemostatic procedures (P < or =0.003), whereas the incidence of postoperative epididymitis positively correlated with a preoperative vasectomy and a closed drainage system (P <0.0005).

CONCLUSIONS

Since the 1970s, the rates of blood transfusions and morbidity have decreased for patients undergoing TURP. Advances in techniques, instrumentation, and surgical and perioperative management, including anesthesia, have made TURP a relatively safe procedure, and it remains an effective means for treating patients with BPH.

[Mutation of p53 gene and genomic instability in testicular tumors]

BACKGROUND

During the past decade, studies of human cancer have begun to yield molecular information on the identify of the multiple genetic changes in the development and progression of tumorigenesis. We investigated alterations of p53 and genomic instability in testicular tumors.

MATERIALS AND METHODS

Polymerase chain reaction (PCR) single-strand conformation polymorphism was performed for analysis from exons 5 to 8 of p53 gene in 22 cases and PCR-microsatellite instability analysis using 8 microsatellite markers were conducted in 19 cases of testicular tumor.

RESULTS

No mutations were noted for exons 5 to 8 of the p53 gene. Differences in unrelated microsatellites for tumor and corresponding normal DNA were detected in 5 of 19 (26.3%) cases examined. Alterations noted in more than 2 microsatellites were observed in 3 of 19 (15.8%) and categorized as replication error (RER) phenotype. Two of 7 (28.6%) seminomatous and 1 of 12 (8.3%) non-seminomatous testicular tumors patients showed RER. Two of 16 (12.5%) stage T1-3N0M0 and 1 of 3 (33.3%) stage T1-3N1-3M0-1 showed RER.

CONCLUSIONS

Alterations in microsatellite instability may be involved in the development of testicular tumor.

[The definition and frequency of clinically unimportant prostate cancer in the patients treated with radical prostatectomy]

In autopsy studies more than 20% of men > 50 years old have prostate cancer, yet the lifetime risk of developing clinical cancer of the prostate is much less. Thus, early detection should not aim to all cancers, but only those that are potentially morbid or lethal. In the detailed morphometric examination of radical prostatectomy specimens, we found only 10% of the 610 patients had clinically unimportant cancer. Of the 207 patients with non-palpable tumor, 11% had clinically unimportant cancer compared to 10% of the 403 patients with palpable tumor (p = 0.52). And these non-palpable tumor were more likely to be curable disease compared to palpable tumor (66% versus 57%, p = 0.007). All recent studies indicated that most of prostate cancers which were detected with current diagnostic tests were clinically important and, therefore, should be treated aggressively.

Clinical and pathological significance of the level and extent of capsular invasion in clinical stage T1-2 prostate cancer

This study was performed to assess the relationship between the level and extent of prostatic capsular invasion (PCI) by cancer and the clinical and pathological features and prognosis of early-stage prostate cancer. We conducted a retrospective analysis of the clinical (age, stage, grade, prostate specific antigen [PSA] level) and pathological (tumor volume, stage, grade, surgical margins) features of 688 patients treated with radical prostatectomy to determine the pathological features and probability of recurrence associated with various levels of PCI. Radical prostatectomy specimens were serially sectioned and examined by whole-mount technique. Progression-free probabilities (PFP) after radical prostatectomy were determined by Kaplan-Meier and Cox proportional hazards regression analysis. Progression was defined as a rising serum PSA < or = 0.4 ng/mL or clinical evidence of recurrent cancer. Increasing clinical stage, Gleason grade in the biopsy specimen, and pretreatment serum PSA levels were each associated with increasing levels of PCI (P < .001). In the radical prostatectomy specimen, increasing levels of PCI were significantly associated with increasing tumor volume (P < .001), Gleason grade (P < .0001), seminal vesicle involvement (SVI, P < .001) and lymph node metastases (+LN, P < .001). None of 138 patients without capsular invasion had SVI or lymph node metastases (+LN), and all remained free of progression, even though some had large volume (up to 6.26 cm3) or poorly differentiated (Gleason sum up to 8) cancers. Invasion into the capsule (n = 271) was occasionally associated with SVI (6%) or +LN (3%) and a significantly (log-rank test) lower PFP of 87% at 5 years. Focal and extensive extraprostatic extension (EPE) were associated with progressively increased risk of SVI and +LN and lower PFP (73% and 42%, respectively). In a multivariate analysis, the level of PCI was an independent prognostic factor (P < .001). There is a strong association between the level of invasion of cancer into or through the prostatic capsule and the volume, grade, pathological stage, and rate of recurrence after radical prostatectomy. Prostate cancer does not appear to metastasize in the absence of invasion into the capsule regardless of the volume or grade of the intracapsular tumor. Subclassification of patients according to the levels of PCI provides valuable prognostic information.

Use of systematic biopsy results to predict pathologic stage in patients with clinically localized prostate cancer: a preliminary report

BACKGROUND

The purpose of this study was to determine the ability of clinical tests to predict advanced pathologic stage (seminal vesicle invasion, pT3c, or pelvic lymph node metastases, pN+).

METHODS

T stage, PSA, PSA density, and pathologic features in systematic biopsy specimens were correlated with pathologic stage in 190 consecutive patients with clinically localized (T1-3) prostate cancer detected by systematic needle biopsies and treated with radical prostatectomies.

RESULTS

Thirty-three patients (17%) had an advanced pathologic stage cancer (pT3c or pN+). In logistic regression analysis, the total length of cancer in all biopsy cores (P < 0.0005), the percent of poorly-differentiated cancer in each specimen (P< 0.021), and serum PSA (P< 0.028) were the only significant predictors of advanced stage. A model was constructed to predict advanced stage: if the PSA was > or = 6 ng/mL and 4 or more biopsy cores were positive and the total length of cancer in all cores was > or = 20 mm and at least 10% of the cancer was poorly-differentiated, then 14 (93%) of 15 patients had an advanced pathologic stage cancer compared to 11% of the remaining 175 patients (P < 0.0005).

CONCLUSION

The pathologic features of cancer in systematic needle biopsy specimens more accurately predicts which patients have advanced stage cancer than standard clinical tests alone.

Molecular mechanism of human CD38 gene expression by retinoic acid. Identification of retinoic acid response element in the first intron

CD38 is a nonlineage-restricted type II transmembrane glycoprotein possessing ecto-NAD+ glycohydrolase activity. Because of its unique expression pattern in lymphocyte differentiation, it appears to function as an immunoregulatory molecule. We previously reported that CD38 was specifically induced by all-trans-retinoic acid (RA) in human promyelocytic leukemia HL-60 cells. Here we studied the molecular mechanism of the RA-dependent induction of human CD38. The expression of CD38 mRNA by RA appeared to be caused by the transcriptional stimulation of the gene, since it was blocked by an RNA synthesis inhibitor, but not by a protein synthesis inhibitor. In search of the RA response element (RARE) possibly present in human CD38 gene promoter, we isolated and sequenced the genomic DNA covering the 5'-flanking region, exon 1, and partial intron 1. Transient transfection experiments revealed that the responsiveness to RA was conferred through an RARE consisting of two direct repeat TGACCT-like hexamer motifs with a 5-nucleotide spacer, which was located in the first intron rather than the 5'-flanking region of the CD38 gene. This RARE interacted with heterodimer composed of RA receptor and retinoid X receptor in vitro. Thus, the RA-induced expression of the human CD38 gene was demonstrated to be mediated through the RARE located in the first intron.

Detection of prostate carcinoma using prostate specific antigen, its density, and the density of the transition zone in Japanese men with intermediate serum prostate specific antigen concentrations

BACKGROUND

This study was undertaken to determine whether the prostate specific antigen (PSA) density (PSAD) and PSAD of the transition zone (PSADT) are useful in the detection of prostate carcinoma in Japanese men with intermediate levels of serum PSA.

METHODS

Two hundred and eighty-seven Japanese men with intermediate serum PSA levels (2.1 ng/mL to 10 ng/mL) underwent measurement of prostate volume by transrectal ultrasound (TRUS) and systematic biopsy under TRUS guidance. The volume of the transition zone was also measured by TRUS in 134 patients. The PSAD and PSADT were determined for each patient, and their relationship to prostate carcinoma detection was examined.

RESULTS

Prostate carcinoma was detected in 30 of 287 patients (10.5%). Although the serum PSA levels were similar in patients with benign and malignant prostate disease (P = 0.541), the prostate volume (P 0.0009) and PSAD (P < 0.0001) differed significantly in the two groups; in the patients with prostate carcinoma, the prostate volume was smaller, and the PSAD higher, than in the patients with benign disease. At the PSAD cutoff value of 0.18 ng/mL/cm3 or greater, the sensitivity was 70% and the specificity was 67% for the diagnosis of prostate carcinoma. The PSAD was found to be significantly better in the differentiation between benign and malignant prostate disease than the serum PSA in the receiver operating characteristic analyses (P = 0.045). However, the receiver operating characteristic curve for PSAD was not significantly different compared with that for PSA in the men with negative digital rectal examination findings. Prostate carcinoma was detected in 9.0% (12 of 134) of the patients who underwent PSADT determination. Receiver operating characteristic analyses showed that PSADT was not superior to PSA in the detection of prostate carcinoma.

CONCLUSIONS

In Japanese men with intermediate serum PSA concentrations, PSAD offers additional information useful in the detection of prostate carcinoma, but PSADT does not. Although use of PSAD may decrease the number of unnecessary biopsies, a significant number of prostate carcinomas may be overlooked. Therefore, the authors recommend that serum PSA levels continue to be used as an indicator for biopsy in Japanese men.

The ratio of free to total serum prostate specific antigen and its use in differential diagnosis of prostate carcinoma in Japan

BACKGROUND

To improve the clinical usefulness of prostate specific antigen (PSA), unique methods have been proposed. The percentage of free PSA in serum facilitates the distinction between benign histologic conditions and prostate carcinoma while retaining high sensitivity.

METHODS

Using monoclonal antibodies, an AIA total PSA assay system was established that recognized PSA equally in free or complex form. The clinical usefulness of the ratio of two different molecular forms of PSA was investigated using 268 archival serum samples.

RESULTS

Men with prostate carcinoma had significantly lower ratios of free to total PSA than those with benign prostatic hyperplasia (BPH) (P = 0.0001). At total PSA levels between 2.1 and 10 ng/mL, medians of total PSA were not significantly different between men with prostate carcinoma and men with BPH. Differences in median percentages of free PSA for these two groups were statistically significant (P = 0.0001). The ratio of free to total PSA was useful for identifying prostate carcinoma in palpably benign glands with total PSA of 2.1-10 ng/mL (P = 0.0001), whereas total PSA was not useful for such identification. When calculated for low total PSA levels between 2.1 and 4 ng/mL, sensitivity and specificity were 91.7% and 72.2%, respectively, with a cutoff value of 17%. This ratio of free to total PSA was as useful as PSA density in receiver-operating curve analysis.

CONCLUSIONS

The use of the ratio of free to total PSA renders total PSA of greater use of distinguishing prostate carcinoma and is applicable to patients with low total PSA. Elderly men with a clinical diagnosis of BPH who are scheduled for surgery may benefit from the determination of this ratio.

Preoperative serum prostate-specific antigen, clinical stage and Gleason sum as basis for predicting final pathological stage in Japanese patients with prostate cancer

By logistic regression analysis and log-likelihood ratio chi-square test, the usefulness of preoperative variables (prostate specific antigen [PSA], clinical stage and biopsy Gleason sum) for predicting the final pathological stage was assessed in 77 patients with clinically resectable prostate cancers. Pathologically, 32 (41.6%) had organ-confined disease. Extracapsular extension was found in 41 (53.2%), seminal vesicle involvement in 30 (39.0%), positive pelvic lymph nodes in 10 (13.0%) and a positive surgical margin in 27 (35.1%). Each preoperative variable was found to be significantly associated with the final pathological stage. Any combination of these variables was more predictive for extraprostatic disease, compared with each individual variable. Extraprostatic spread was found more frequently in patients with lower serum PSA in this Japanese elderly male population compared with North American males. These preoperative variables considered in combination may provide valuable information for management decisions related to prostate cancer. Serum PSA alone cannot reliably predict pathological stage on an individual basis except in patients with a PSA level of 20 ng/ml or greater. The high incidence of extraprostatic spread at intermediate PSA underscores the importance of selecting an ideal cutoff value for PSA-based screening in a Japanese male population.

Risk factors for urinary incontinence after radical prostatectomy

PURPOSE

We identified risk factors associated with urinary incontinence after radical retropubic prostatectomy.

MATERIALS AND METHODS

The time from operation until urinary continence was achieved was determined by chart review and questionnaire in 581 patients who were continent before undergoing radical retropubic prostatectomy between 1983 and 1994. Using univariate and multivariate analyses of data gathered prospectively, we examined risk factors associated with incontinence in these patients.

RESULTS

The actuarial rate of urinary continence at 24 months was 91% for the entire patient population and 95% for those treated after 1990. Many factors were associated with the risk of incontinence in univariate Cox proportional hazards regression analysis (patient age and weight, degree of obstructive voiding symptoms, prior transurethral resection of the prostate, clinical stage, intraoperative blood loss, resection of neurovascular bundles, postoperative anastomotic stricture and technique of vesicourethral anastomosis). However, in a multivariate analysis the factors that were independently associated with increased chance of regaining continence were decreasing age, a modification in the technique of anastomosis (introduced in 1990), preservation of both neurovascular bundles and absence of an anastomotic stricture. With introduction of the new surgical technique in 1990 the median time to continence decreased from 5.6 to 1.5 months and the rate of continence at 24 months increased from 82 to 95%.

CONCLUSIONS

While the risk of urinary incontinence after radical prostatectomy is related to the uncontrollable factor of patient age, it is also sensitive to the surgical technique used.

Characterization of dextran sulfate-induced guinea pig tracheal plasma extravasation

We examined the effect of dextran sulfate on guinea pig tracheal vascular permeability. I.v. injection of dextran sulfate (10-100 mg/kg) with captopril (1 mg/kg) induced guinea pig tracheal plasma extravasation. The i.v. administration of bradykinin (0.8-8 micrograms/kg) with captopril (1 mg/kg) also induced plasma extravasation. Bradykinin B2 antagonists, D-Arg[Hyp3-Thi5-D-Tic7-Tic8]-bradykinin (NPC 16731) and D-Arg[Hyp3-Thi5-D-Tic7-Oic8]-bradykinin (Hoe 140), reduced both dextran sulfate (32 mg/kg)- and bradykinin (2.5 micrograms/kg)-induced tracheal plasma extravasation in a dose-dependent manner. However, a cyclooxygenase inhibitor, indomethacin (1 mg/kg), and a neurokinin antagonist, [N-[N2-[N-[N-[N-[2,3-didehydro-N-methyl-N-[N-[3-(2-pentylphenyl )- propionyl]-L-threonyl]tyrosyl-L-leucynyl]-D-phenylalanyl]-L-a llo-threonyl]-L-asparaginyl]-L-serine-D-lactone] (FK 224) (1 mg/kg), had no effect on tracheal plasma extravasation induced by dextran sulfate and bradykinin. Dextran sulfate (32 mg/kg) with captopril (1 mg/kg) greatly increased the bradykinin level in guinea pig plasma. This evidence suggests that dextran sulfate releases bradykinin in guinea pig plasma and causes guinea pig tracheal plasma extravasation via the activation of bradykinin B2-receptors.

[A case of congenital penile curvature]

A case of congenital penile curvature is reported. A 21-year-old man was admitted because of penile pain curvature to the left at the erection and the difficulty of intercourse. He had no signs of Peyronie's disease and no history of penile fracture so that he was considered to have congenital penile curvature. By Nesbit's method the curvature of the penis was appropriately corrected. There were no signs of recurrence at either 1 or 5 months after the operation.

[Common bile duct fistula caused by hepatic arterial infusion chemotherapy]

We often use hepatic arterial infusion chemotherapy to control recurrence of metastatic cancer of liver. Recently, we encountered a case of common bile duct fistula caused by hepatic arterial infusion chemotherapy. A 61-year-old man had undergone right hepatic lobectomy for liver metastasis of gastric cancer, 7 months after total gastrectomy. A hepatic arterial infusion catheter was placed. Since then he has received continuous and/or bolus hepatic artery infusion of 5-FU, ADR and CDDP+5-FU. There was a recurrence of gastric cancer in segment 2 of the liver. On his second admission, when we administered contrast medium to the infusion port, a common bile duct was found.

Distinguishing clinically important from unimportant prostate cancers before treatment: value of systematic biopsies

PURPOSE

We assessed the ability of diagnostic tests to distinguish clinically unimportant cancers.

MATERIALS AND METHODS

We correlated T stage (based on digital examination and ultrasound), prostate specific antigen (PSA), PSA density and pathological features of cancer in systematic biopsy specimens with features of cancer in 170 radical prostatectomy specimens. Clinically unimportant cancers were defined as small (0.5 cm.3 or less), well or moderately differentiated and confined to the prostate.

RESULTS

Of the patients 10% had an unimportant cancer. On logistic regression analysis the 2 significant predictors were maximum length of cancer in any core and PSA density. Of 12 patients with maximum cancer length 2 mm. or less and PSA density less than 0.1., 75% had an unimportant cancer compared to 5% of the remaining 158 (p < 0.0005).

CONCLUSIONS

Quantitative analysis of systematic biopsy specimens combined with PSA density provides valuable staging information and helps to identify cancers of low biological potential.

Results of radical prostatectomy in men with clinically localized prostate cancer

OBJECTIVE

To assess the results of radical prostatectomy in men with early prostate cancer.

DESIGN

Retrospective, nonrandomized, multi-institutional pooled analysis.

SETTING

Eight university medical centers in the United States and Europe.

PATIENTS

A total of 2758 men with stage Tl and T2 prostatic cancer.

MAIN OUTCOME MEASURES

Disease-specific and metastasis-free survival rates.

RESULTS

Tumor grade was the most important preoperative factor in determining outcome. Disease-specific survival 10 years following surgery and associated 95% confidence intervals were 94% (range, 87%-98%), 80% (range, 74%-85%), and 77% (range, 65%-86%) for those men with grade 1, 2, and 3 tumors, respectively. Metastasis-free survival at 10 years was 87% (range, 78%-92%), 68% (range, 62%-73%), and 52% (range, 38%-64%) for patients with grade 1, 2, and 3 cancers, respectively.

CONCLUSIONS

Radical prostatectomy leads to high 10-year disease-specific survival rates in men with all tumor grades. However, caution is needed in comparing these results with similar studies of alternative treatment strategies, such as watchful waiting, due to the inherent potential biases in uncontrolled trials. Nevertheless, these results offer the best currently available estimates of 10-year outcome of radical prostatectomy in men with clinically localized prostate cancer and may be useful in counseling patients with early malignancy.

Effects of omega-conotoxin GVIA on the activation of capsaicin-sensitive afferent sensory nerves in guinea pig airway tissues

We examined the effects of Ca2+ channel antagonists on various respiratory reactions induced by the activation of capsaicin-sensitive afferent sensory nerves. Intravenous (i.v.) injection of the N-type Ca2+ channel antagonist omega-conotoxin GVIA (CgTX) (1-20 micrograms/kg) dose-dependently inhibited capsaicin-induced guinea pig bronchoconstriction, whereas i.v. administration of the L-type antagonist nicardipine (100 micrograms/kg), the P-type antagonist omega-agatoxin IVA (AgaTX) (20 micrograms/kg) or the OPQ family-type antagonist omega-conotoxin MVIIC (CmTX) (20 micrograms/kg) had no effect. However, CgTX (20 micrograms/kg) failed to inhibit substance P-induced guinea pig bronchoconstriction. CgTX (20 micrograms/kg) significantly inhibited cigarette smoke-induced guinea pig tracheal plasma extravasation, but not the substance P-induced reaction. CgTX also reduced electrical field stimulation-induced guinea pig bronchial smooth muscle contraction (0.01-10 microM) and capsaicin-induced substance P-like immunoreactivity release from guinea pig lung (0.14 microM). This evidence suggests that N-type Ca2+ channels modulate tachykinin release from capsaicin-sensitive afferent sensory nerve endings in guinea pig airway tissue.

[Renal cell carcinoma in childhood: a case report]

A case of renal cell carcinoma (RCC) in a teenage patient is reported. A 13-year-old girl visited our hospital with the complaint of dyspnea and right abdominal mass. CT scan and chest X-P revealed a right renal tumor with multiple lung metastasis. Wilms' tumor was suspected and a combination chemotherapy consisting of actinomycin D and vincristin was performed. Since the tumor was insensitive to these agents, open biopsy was done. The pathological findings showed clear cell renal cell carcinoma. Despite the administration of alpha interferon, 5-FU and cimetidine, the disease was progressive and the patient died 5 months after diagnosis. It is important to consider the possibility of renal cell carcinoma in teenage patients with a renal mass, since more than 40% of the renal tumors in this age group are renal cell carcinomas.

[Renal cell carcinoma associated with circumferential "ring-like" calcification]

A 37-year-old man was found to have large calcification in the left kidney in a health check. This calcification has not changed in size during 3 years with computerized tomographic (CT) studies. However, a suspicious lesion for a malignant tumor with the calcification was suggested by a magnetic resonance image (MRI) study. Thus, the patient underwent tumor enucleation and the histology showed the mixed typed renal cell carcinoma. Although it remains controversial, partial nephrectomy or tumor enucleation would be considered in a case of renal cell carcinoma with calcification, which is usually considered to have a favorable prognosis compared to that of a tumor without a calcification.

Impalpable prostate cancer: clinicopathological features

OBJECTIVE

To determine the clinicopathological features of impalpable prostate cancer.

PATIENTS, MATERIALS AND METHODS

The numbers of T1a and T1b cancers detected in transurethral resections of the prostate (TURP) performed before and after the advent of the test for serum prostate-specific antigen (PSA) were compared and the incidence of T1 disease in specimens from 400 consecutive radical prostatectomies examined.

RESULTS

The incidence of T1b disease detected at TURP decreased significantly between the periods examined, but that of T1a was unaffected. Similarly, in radical prostatectomy specimens, T1b cancers were largely replaced by T1c and impalpable T2 cancers detected by ultrasonography.

CONCLUSIONS

Cancers detected incidentally at TURP tend to be small T1a tumours, possibly suitable for conservative management. T1b cancers are likely to be detected by PSA level and treated radically. T1c and impalpable T2 cancers are morphologically unlike T1b disease and justifiably belong in separate stages in the current UICC staging system.

A non-randomized comparative study of visual laser ablation and transurethral resection of the prostate in benign prostatic hyperplasia

BACKGROUND

Transurethral resection of the prostate (TURP) has been the preferred surgical treatment for benign prostatic hyperplasia (BPH) for the past 50 years. Alternative methods for treating BPH such as visual laser ablation (VLAP) have been established during the past decade. In order to assess the safety and efficacy of VLAP, this alternative method was performed using a Urolase fiber and neodymium: yttrium-aluminum-garnet laser, and compared to results obtained in patients treated with TURP for BPH.

METHODS

In this non-randomized comparative study, 100 BPH patients were equally split between treatment with VLAP or TURP, and their cases compared. The efficacy was assessed using an International Prostate Symptom Score, urinary flow rates, post-void residual urinary volume and an estimated prostate volume.

RESULTS

There was a clinically significant improvement in all parameters in both groups. In the VLAP and TURP groups, 92.0% and 81.6%, 90.2% and 86.2 and 93.1% and 100.0% were categorized as effectively-treated cases at 3, 6 and 12 months post-operatively, respectively. No severe side effect was seen in VLAP group. The total and post-operative lengths of hospitalization in the VLAP group were shorter, but the duration of post-operative bladder irrigation was longer in these patients.

CONCLUSIONS

Although TURP remains the standard surgical treatment for BPH, VLAP is associated with less morbidity and the clinical outcome is similar compared to patients treated with TURP. VLAP in conjunction with TURP may result in less risk of postoperative urinary retention and vesical irritability.

[Early detection of prostate cancer-results of a prostate specific antigen-based detection program at a "multiphasic screening"]

Determination was made of serum PSA in the early detection of prostate cancer in a population of 1,227 men aged 55 years or older who visited a "human dock". "Human dock" is a unique health examination facility open to public in Japan. Recommendation for biopsy was made based solely on this parameter when its value exceeded 2.0 ng/ml in IMx immunoenzymetric assay (Dinabot Co.). Of these, 162 (13.2%) had elevated values. The proportion of males with serum PSA greater than 4.0 ng/ml was only 3.6%. Of the 109 males who underwent ultrasound guided biopsies, 17 cancers were detected, the cancer detection rate thus being 1.4%. Most of these cases (82.4%) were clinically localized cancers. Eight patients with cancer had serum PSA levels below 4.0 ng/ml including 6 less than 3.0 ng/ml. Radical prostatectomy was conducted on 14 patients. All had histologic features of clinically significant cancer and 64.3% were pathologically confined. Oriental elderly males appear to have lower serum PSA than western counterparts. The optimal cutoff of serum PSA for early detection should be examined further in oriental male populations. Differences in the incidence of prostate cancer between ethnic groups may have been overestimated in previous studies owing in part to unawareness by the physician and general public. Though the application of PSA for early detection will likely disclose greater numbers of prostate cancers in Japan, whether early detection reduces mortality by minimizing risk of death from cancer remains a point to be clarified.

Is prostate-specific antigen density more useful than prostate-specific antigen levels in the diagnosis of prostate cancer?

OBJECTIVES

To compare the performance of prostate-specific antigen (PSA) levels with the performance of PSA density (PSAD), the ratio of the serum to the size of the prostate, as predictors of the presence of prostate cancer.

METHODS

We analyzed the results of digital rectal examination (DRE), transrectal ultrasonography (TRUS), serum PSA levels, and PSAD in 244 patients who had a needle biopsy of the prostate.

RESULTS

Cancer was detected in 110 patients (45%). Compared with DRE, TRUS and serum PSA levels 4.0 ng/mL or higher, PSAD at a cutoff point of 0.15 ng/mL/cm3 was significantly more specific and had a higher positive predictive value than each of the other tests but was significantly less sensitive than TRUS and PSA (P < 0.05 for each). In a receiver operating characteristic analysis, PSAD was significantly more accurate than PSA (P < 0.001). In 80 patients with a normal PSA, PSAD added no additional information, and PSAD was not able to identify a subset at low risk. In 82 patients with a high PSA level (10 ng/mL or higher), 15% had a PSAD less than 0.15 and only 8% had a cancer.

CONCLUSIONS

Overall, PSAD was significantly more accurate than PSA for predicting the results of needle biopsy of the prostate, but in practice PSAD proved useful in only a small subset of patients. If the serum PSA level was high but the PSAD was low, cancer was rarely detected. These patients may be suitable candidates for careful follow-up rather than early repeat biopsy.

Prognostic significance of positive surgical margins in radical prostatectomy specimens

PURPOSE

The prognostic significance of positive surgical margins in radical prostatectomy specimens was assessed.

MATERIALS AND METHODS

The interval to progression (increasing prostate specific antigen level) was measured in 478 patients by status of the surgical margins.

RESULTS

At 5 years, the nonprogression rate was 64% for patients with and 83% for those without positive surgical margins. With a high grade cancer, seminal vesicle invasion or lymph node metastases, positive surgical margins had no effect on prognosis; with extracapsular extension and a Gleason score of 6 or less positive surgical margins were associated with a higher progression rate.

CONCLUSIONS

Prognosis was adversely affected by positive surgical margins only in moderately differentiated cancers with extracapsular extension alone. If the cancer is otherwise confined, positive surgical margins are associated with an excellent prognosis unlikely to be improved by adjuvant therapy.

Early detection of prostate cancer. Results of a prostate specific antigen-based detection program in Japan

BACKGROUND

Prostate cancer increasingly is becoming a medical problem in Japan. To maximize the chance for cure, extensive effort is being made to detect prostate cancer while confined to the gland.

METHODS

Determination was made of serum prostate specific antigen (PSA) in the early detection of prostate cancer in an Asian male population aged 55 years or older. Recommendation for biopsy was based solely on this parameter when its value exceeded 2.0 ng/ml in IMx immunoenzymetric assay.

RESULTS

Of 1189 men, 150 (12.6%) had elevated values. The proportion of males with serum PSA greater than 4.0 ng/ml was only 3.4%. Of the 99 males who underwent ultrasound-guided biopsies, 16 cancers were detected, a cancer detection rate of 1.3%. Most of these (81.3%) were clinically localized cancers. Seven patients with cancer had serum PSA levels below 4.0 ng/ml including 5 less than 3.0 ng/ml. These tumors would have been overlooked if the conventional cutoff levels of 4.0 ng/ml had been applied. Radical prostatectomy was conducted on 13 patients. All had histologic features of clinically significant cancer and 69.2% were pathologically confined within the gland.

CONCLUSIONS

Elderly Asian males appear to have lower serum PSA than their Western counterparts. The optimal cutoff of serum PSA for early detection should be examined further in Asian male populations. Differences in the incidence of prostate cancer between ethnic groups may have been overestimated in previous studies owing in part to unawareness by the physician and general public. Though the frequent use of more sophisticated diagnostic modalities will likely disclose greater numbers of prostate cancers in Japan, whether early detection reduces mortality by minimizing risk of death from cancer remains a point to be determined.

The role of surgery in the management of pediatric pelvic rhabdomyosarcoma

PURPOSE

We assessed the role of surgery, particularly exenteration, in the treatment of children with lower urinary tract and pelvic rhabdomyosarcoma.

MATERIALS AND METHODS

We treated 23 children with bladder and/or prostate (11), or pelvic retroperitoneal tumors (12). Initial management was tumor resection in 6 cases, anterior pelvic exenteration in 5 and biopsy only in 12, combined with chemotherapy in 23 and radiotherapy in 20.

RESULTS

The bladder salvage rate for surviving patients with pelvic tumors was 92% versus 27% for those with prostate/bladder tumors. Estimated 5 and 10-year survival probability for patients with pelvic retroperitoneal tumors was 49 +/- 50% compared to 81 +/- 24% for those with bladder and/or prostate tumors (log rank test, p = 0.11).

CONCLUSIONS

Exenterative surgery is frequently required to achieve a durable complete response.

[Clinicopathological study of nonpalpable and nonvisible (stage T1c) prostate cancer]

Clinical and pathologic characteristics of stage T1c disease (nonpalpable and nonvisible cancer) was studied retrospectively in men who underwent radical prostatectomy in order to better understand this disease entity. Findings in stage T1c disease (16 patients) were directly compared with those in stage T2b disease (11 patients). No significant difference was observed between these groups with regard to age, preoperative serum prostatic acid phosphatase level, prostatic weight, numbers of tumor foci, total tumor volume, volume of index cancer and tumor grade (p > 0.05). Preoperative prostate specific antigen concentration was significantly lower in stage T1c group (p < 0.05). Substantially larger number of patients with stage T1c disease had pathologically organ confined disease when compared with T2b group (86.7% versus 45.5%, p < 0.05). Seventy-five percent (12/16) of stage T1c and 90.9% (10/11) of stage T2b disease were considered clinically significant. Most of stage T1c disease is organ confined and clinically significant. Clinical and pathologic features of these tumors are similar to those in T2b disease. Twenty-five percent of stage T1c disease, however, are small and thus may potentially be overtreated. Enhanced detection of prostate cancer achieved with modern technology can lead to undesirable treatment of clinically insignificant tumors. Preoperative diagnostic modalities which can reliably distinguish groups of tumor with different biological potential are needed to overcome this contradiction.