Effectiveness of complete versus partial androgen withdrawal therapy for the treatment of prostatic cancer as studied in the Dunning R-3327 system of rat prostatic adenocarcinomas.

Standard initial therapy for metastatic prostatic cancer involves surgical or chemically induced castration. Castration lowers the serum testosterone level by over 90% but does not completely eliminate all potential serum androgens (i.e., it induces a partial androgen withdrawal). This has led some investigators to suggest that a more complete form of androgen withdrawal in which the very low levels of serum androgens remaining after castration are neutralized by the simultaneous treatment with a direct acting antiandrogen (i.e., complete androgen withdrawal) might be more effective than simply castration alone. To determine whether complete androgen withdrawal is any more effective than partial androgen withdrawal therapy, the slow growing, well differentiated H and the fast growing, poorly differentiated G sublines of the serially transplantable Dunning R-3327 system of rat prostatic adenocarcinomas were used as a test system since both of these cancers are androgen responsive. These studies demonstrated that: (a) complete androgen withdrawal consisting of surgical castration in combination with daily treatment with the potent antiandrogen, cyproterone acetate, was no more effective in terms of tumor growth retardation or overall host survival than was partial androgen withdrawal induced by castration alone; (b) serum testosterone levels must be maintained below 0.5 ng/ml but do not have to be completely eliminated to produce the maximum therapeutic response; and (c) prostatic cancers are more sensitive than is the normal prostate to growth stimulation by serum testosterone.

Prognostic value of Ki67 in localized prostate carcinoma: a multi-institutional study of >1000 prostatectomies.

BACKGROUND: Expanding interest in and use of active surveillance for early state prostate cancer (PC) has increased need for prognostic biomarkers. Using a multi-institutional tissue microarray resource including over 1000 radical prostatectomy samples, we sought to correlate Ki67 expression captured by an automated image analysis system with clinicopathological features and validate its utility as a clinical grade test in predicting cancer-specific outcomes. METHODS: After immunostaining, the Ki67 proliferation index (PI) of tumor areas of each core (three cancer cores/case) was analyzed using a nuclear quantification algorithm (Aperio). We assessed whether Ki67 PI was associated with clinicopathological factors and recurrence-free survival (RFS) including biochemical recurrence, metastasis or PC death (7-year median follow-up). RESULTS: In 1004 PCs (∼4000 tissue cores) Ki67 PI showed significantly higher inter-tumor (0.68) than intra-tumor variation (0.39). Ki67 PI was associated with stage (P<0.0001), seminal vesicle invasion (SVI, P=0.02), extracapsular extension (ECE, P<0.0001) and Gleason score (GS, P<0.0001). Ki67 PI as a continuous variable significantly correlated with recurrence-free, overall and disease-specific survival by multivariable Cox proportional hazard model (hazards ratio (HR)=1.04-1.1, P=0.02-0.0008). High Ki67 score (defined as ⩾5%) was significantly associated with worse RFS (HR=1.47, P=0.0007) and worse overall survival (HR=2.03, P=0.03). CONCLUSIONS: In localized PC treated by radical prostatectomy, higher Ki67 PI assessed using a clinical grade automated algorithm is strongly associated with a higher GS, stage, SVI and ECE and greater probability of recurrence.

Characterization of a novel androgen-sensitive, prostate-specific antigen-producing prostatic carcinoma xenograft: LuCaP 23.

Prostatic carcinoma has proven extremely difficult to establish as cell lines or xenografts. In this article, we describe a new series of prostate cancer xenografts propagated in athymic mice, designated LuCaP 23, developed from prostate metastases harvested at autopsy shortly after death. Tumor from three separate metastatic deposits was developed into three xenograft sublines: two from lymph node metastases (LuCaP 23.1 and 23.8) and one from a liver metastasis (LuCaP 23.12). Fluorescence in situ hybridization analysis confirms the xenografts are human. Histologically, the xenografts are comprised of columnar epithelial cells arranged in a glandular pattern. Tumor doubling times range from 11 to 21 days for the three sublines. The cells secrete large amounts of prostate-specific antigen (PSA) with PSA indices of 1.27, 1.63, and 5.21 ng/ml/mm3 for the mice bearing the LuCaP 23.1, 23.8, and 23.12 sublines, respectively. Following androgen deprivation a temporary decrease in PSA secretion and a decrease in tumor size are noted in most tumors. Eventually, the tumors become androgen independent and resume growth in castrate hosts. The degree of PSA response to castration and time to PSA nadir correlate with time to progression. Thus, unlike most existing models of prostatic carcinoma, this novel xenograft exhibits many phenotypic characteristics of clinical prostatic carcinoma, including androgen sensitivity. These properties make this xenograft an excellent model for future study.

Early tumor cell dissemination in patients with clinically localized carcinoma of the prostate.

Because a significant number of patients with pathologically organ-confined carcinoma of the prostate subsequently develop recurrent disease, metastasis may occur much earlier than previously believed. We have used a reverse transcription-PCR assay for prostate-specific antigen mRNA and an immunocytochemical staining method for cytokeratins to test this hypothesis in paired peripheral blood (PB) and bone marrow (BM) specimens from 71 patients with clinically localized disease before radical prostatectomy, 14 patients with advanced-stage carcinoma of the prostate, and 30 controls (young healthy volunteers, patients without prostate disease, and patients with benign prostatic hyperplasia). Controls were negative in BM and PB. Fifty-six% of patients with organ-confined tumors (pT2) and 73% of those with extracapsular extension (pT3) were positive in the BM versus 16% of those with pT2 tumors and 27% of those with pT3 tumors in the PB. Patients with advanced-stage disease were positive in 86% of BM versus 71% of PB. The sensitivity of the immunocytochemistry assay to detect tumor cells was lower as compared with the reverse transcription-PCR assay. The results suggest that tumor cell dissemination occurs early during disease progression. Prostate cells seem to preferentially concentrate in the BM rather than the PB, which may be due to sequestration there by homing mechanisms. As the rate of detection in the BM exceeds the proportion of patients with subsequently progressing disease, we hypothesize that only a subset of these cells can survive in the BM and evolve to clinically apparent disease.

Prostate cancer.

Prostate carcinoma is a growing concern in our aging society. While the disease often follows a indolent course, it is the second leading cause of cancer-related deaths in males. Prostate cancer screening is promising but remains unproven and controversial. The therapy of prostate cancer has changed little over the past 10 years. The tumor remains refractory to conventional chemotherapeutic agents. True containment of this disease will require novel strategies of diagnosis, biologic assessment, and therapy.

Clinical evaluation of the BTA TRAK assay and comparison to voided urine cytology and the Bard BTA test in patients with recurrent bladder tumors. The Multi Center Study Group.

OBJECTIVES: To assess the clinical performance of the BTA TRAK assay and to compare it with that of voided urine cytology (VUC) and the Bard BTA test (BTA) in the detection of recurrent bladder cancer (BC). METHODS: The study was performed on randomly selected archival voided urine samples for many of which VUC and/or BTA information was available. Sensitivity was determined in samples from patients with histologically confirmed recurrent BC. Specificity was determined in samples from healthy volunteers, patients with three categories of current medical conditions, and patients with a history of BC but no current evidence of disease. RESULTS: The TRAK assay was positive in 156 of 216 samples for patients diagnosed with BC, for an overall sensitivity of 72%. Mean values increased with progressing grade and stage of disease. In the comparison between TRAK and VUC, the overall sensitivities were 68% and 25%, respectively (P < 0.001). For Stages Ta and T1 and for all tumor grades, the sensitivity of the TRAK assay was significantly greater than that of VUC (P < 0.001). TRAK sensitivity was also significantly better than that of BTA (73% versus 58%, P = 0.005). The specificity of the TRAK assay ranged from 75% in samples from patients with genitourinary disease to 97% in healthy volunteers. CONCLUSIONS: The TRAK assay is superior to VUC and the original BTA test in the detection of BC. The results of the study indicate that the TRAK assay may be a useful adjunct to cystoscopy in the management of patients with recurrent BC.

Detection of circulating prostate cells by reverse transcriptase-polymerase chain reaction of human glandular kallikrein (hK2) and prostate-specific antigen (PSA) messages.

OBJECTIVES: To investigate the clinical value of human glandular kallikrein (hK2) reverse transcriptase-polymerase chain reaction (RT-PCR) for detection of prostate cells in circulation and to compare the results with those obtained from prostate-specific antigen (PSA) RT-PCR. METHODS: We examined peripheral blood (PB) and bone marrow (BM) samples of 13 patients with advanced-stage prostate cancer and 63 patients with clinically localized disease for the presence of circulating prostate cells. An RT-PCR protocol with a two-step amplification cycle and hot-start conditions was used. RESULTS: The limit of detection of the PCR portion is similar for PSA and hK2 (5 to 10 copies of the plasmid containing the cDNA). The RT-PCR limit of detection is one LNCaP cell in 10(8) peripheral blood mononuclear cells (PMBC) for PSA, and one LNCaP cell in 10(7) PMBC for hK2. Of the BM samples obtained prior to radical prostatectomy, 71.4% were positive for PSA mRNA and 41.3% were positive for hK2 mRNA. In PB, the PSA positivity was 19% and hK2 positivity 12.7%. In advanced-stage patients, there were 76.9% PSA-positive samples in BM versus 38.5% hK2-positive samples; 46.2% of patients were positive in PB for PSA versus 30.8% for hK2. CONCLUSIONS: We have developed a sensitive RT-PCR protocol for detection of hK2 mRNA and evaluated the suitability of hK2 mRNA in comparison with PSA mRNA as an additional marker for detection of prostate cells in circulation. Combining results of these two tests increased the sensitivity of detection.

Serum percent free prostate-specific antigen in metastatic prostate cancer.

OBJECTIVES: To define the serum prostate-specific antigen (PSA) isoform profile in patients who have prostate cancer but do not have a prostate gland, that is, men who have had a previous radical prostatectomy (RP) and subsequently persistent disease as evidenced by elevated PSA. PSA can be reliably measured in the serum in two major isoforms: PSA complexed to alpha1-antichymotrypsin and uncomplexed free PSA (fPSA). Multiple investigations have illustrated the usefulness of the free/total PSA proportion (percent fPSA) in differentiating prostate cancer from benign prostate disease in patients who still have their prostate gland in situ. METHODS: Sera were evaluated from 52 men who underwent RP and postoperatively had increased PSA. fPSA and total PSA (tPSA) concentrations were determined using the Abbott AxSYM PSA assays. Percent fPSA was calculated for all patients. RESULTS: Median tPSA was 5.45 ng/mL (range 0.93 to 214.99). Median fPSA was 0.69 ng/mL (range 0.11 to 54.93); the median percent fPSA was 13.3% (range 3.9% to 62.9%). There were 27 (52%) patients with percent fPSA less than 15%, 25 (48%) patients with greater than 15%, and 7 (13%) with greater than 30%. No significant relationship was found between percent fPSA and grade, stage, and severity of disease. Percent fPSA was significantly increased in patients who received hormonal, radiation, or combination treatment versus those who received no treatment (P = 0.02 to 0.0007). CONCLUSIONS: Serum percent fPSA in men after RP with persistent prostate cancer encompasses a wide range of values with no clear stratifying factor or factors. These observations and further serial studies in patients with progressive metastatic disease may be important in determining the mechanism(s) for lower percent fPSA in men with newly diagnosed prostate cancer.

Early detection of recurrent prostate cancer with an ultrasensitive chemiluminescent prostate-specific antigen assay.

OBJECTIVES: Treatment failure after radical prostatectomy is most commonly heralded by an increase in serum prostate-specific antigen (PSA) to detectable levels. We evaluated the clinical utility of an ultrasensitive chemiluminescent PSA assay. METHODS: We evaluated the assay in banked sera obtained from 170 men after radical prostatectomy. Controls consisted of 142 females, 29 men who had undergone cystoprostatectomy without evidence of prostate cancer, and 25 men without evidence of recurrent disease at least 5 years after prostatectomy for organ-confined disease. Lead time to diagnosis of recurrence was based on comparisons with the IMx or Tandem E assays using a cutoff of 0.1 ng/mL (100 pg/mL). RESULTS: The biologic level of detection of this assay is 8 pg/mL. Serum PSA levels were undetectable in 82.4% of females, 86.2% of the cystoprostatectomy patients, and 96% of the radical prostatectomy controls. After radical prostatectomy, PSA levels were undetectable at last check in 104 of 168 (61.9%) men. In the 24 men with prostate cancer recurrence, the enhanced sensitivity of 8 pg/mL provided a mean lead time based on conservative calculations of 12.7 to 22.5 months over conventional assays. Thirty-four of the 41 men with detectable PSA levels and no evidence of disease recurrence had PSA levels of 30 pg/mL or less. CONCLUSIONS: PSA levels are undetectable in most men who do not have recurrence of disease after radical prostatectomy. Low but detectable serum PSA levels less than or equal to 30 pg/mL can be produced by nonmalignant sources of PSA. PSA assays with enhanced sensitivity can detect recurrent prostate cancer with significant lead time over conventional assays.

Oral bropirimine immunotherapy of bladder carcinoma in situ after prior intravesical bacille Calmette-Guérin.

OBJECTIVES: Bropirimine is an oral immunomodulator that has demonstrated anticancer activity in transitional cell carcinoma in situ (CIS) in both the bladder and upper urinary tract. Activity also has been documented in patients after prior therapy with bacille Calmette-Guérin (BCG). To more accurately estimate bropirimine's efficacy in BCG-resistant bladder CIS, a Phase II trial was performed. A separate analysis was performed in additional patients intolerant of BCG toxicity. METHODS: Patients received bropirimine 3.0 g/day by mouth for 3 consecutive days, weekly, for up to 1 year. Bladder biopsies and cytologic examination were performed quarterly. Complete response (CR) required negative biopsy and cytology results. RESULTS: Twenty-one of 86 patients entered were not evaluable. CR was seen in 21 (32%; 95th percentile confidence interval [CI], 21% to 44%) of 65 evaluable patients, including 14 (30%, CI 17% to 43%) of 47 BCG-resistant, and 7 (39%, CI 16% to 61%) of 18 BCG-intolerant patients. Overall, by intent-to-treat analysis, CR was thus seen in 21 (24%) of 86 subjects. Most BCG-resistant patients were failures to BCG without relapse, and had received 12 to 36 (median 12) BCG treatments; intolerant patients had received 4 to 11 treatments (median 6). Response duration ranged from 65 to 810 days, with median not yet reached (but greater than 12 months). Thirteen (15%) of 86 stopped bropirimine due to toxicity. Progression to invasive or metastatic disease during or immediately after therapy was documented in only 4 patients (6%), all nonresponders. CONCLUSIONS: Bropirimine may be an alternative to cystectomy for some patients with bladder CIS who have failed or have not tolerated BCG. Further evaluation to improve responses and durability is warranted.

Improved detection of recurrent bladder cancer using the Bard BTA stat Test.

OBJECTIVES: To evaluate the BTA stat Test in the detection of recurrent bladder cancer. METHODS: Sensitivity and specificity were determined using frozen voided urine samples from patients with recurrent bladder cancer, volunteers, patients with nonurologic conditions, and patients with a history of bladder cancer but free of disease. Results of cytology and the original BTA Test were compared with the sensitivity of the BTA stat Test in a large subgroup of the patients with cancer. RESULTS: The BTA stat Test detected 147 (67%) of 220 recurrent cancers. For those urine samples with previous cytologic and BTA Test results available, cytology had a sensitivity of 23%, the BTA Test 44%, and the BTA stat Test 58% for detection of recurrent cancer (P < 0.001, stat versus cytology). The specificity of the BTA stat Test was 72% for benign genitourinary disease and 95% in healthy volunteers. CONCLUSIONS: The BTA stat Test has high sensitivity and is significantly superior to voided urine cytologic analysis in the detection of recurrent bladder cancer.

Phase I and pharmacokinetic studies with the pentacyclic pyrroloquinone mitoquidone.

Mitoquidone (MTQ) is the first member of a new group of pentacyclic pyrroloquinones developed for clinical evaluation as a potential anticancer agent. MTQ demonstrated good activity in a range of experimental solid tumour models, but was weakly active against standard prescreens such as the P388 murine leukaemia. Bone marrow suppression or other significant toxicity was not observed in preclinical studies. Twenty-seven patients were treated with MTQ given as a 4-h infusion either once every 21 days (150-600 mg/m2), once a week (200 mg/m2 per week), or as 5 daily doses repeated every 28 days (60-180 mg/m2 per day). The major adverse events encountered included nausea and vomiting (in virtually all patients), dyspnoea, tumour-related pain, and thrombocytopenia in several patients with pretreatment bone-marrow impairment. Phase I studies were suspended without a maximum tolerated dose being reached because of formulation difficulties. There were no major responses, although stable disease was observed in a number of patients with gastrointestinal malignancies. Temporary remission of B-symptoms occurred in two patients with lymphoma. The plasma pharmacokinetics of MTQ were investigated using an HPLC assay with fluorescence detection. Linear pharmacokinetics were observed with a terminal plasma half-life of 2.9 +/- 2.1 h (n = 18 doses). The volume of distribution was 3.4 +/- 2.6 l/kg and plasma clearance was 629 +/- 469 ml/min per m2. Several soluble analogues with similar antitumour activity are currently under investigation.

PSA in benign prostatic hyperplasia and prostatic intraepithelial neoplasia.

Prostate specific antigen has become an important adjunct to the digital rectal examination in screening for prostate cancer. The clinician should be familiar with interpretation of this test. Many men with BPH have elevated serum PSA concentrations; however, the majority of these men will have other pathologic processes such as occult cancer, PIN, or acute inflammation that may account for the elevations in serum PSA. Certainly, serial increases in serum PSA should increase concern that occult carcinoma is present. Patients with PIN may also have elevated PSA concentrations. When PIN is associated with elevated PSA, a high incidence of invasive carcinoma is noted on subsequent biopsy. Further investigation into the associations will further refine the clinical utility of this powerful tumor marker.

Advanced prostatic carcinoma. Early versus late endocrine therapy.

Since the landmark observations of Huggins and Hodges in 1941, androgen deprivation has been the mainstay of treatment for advanced-stage prostate cancer. Although early, poorly controlled studies suggested enhanced survival with hormonal therapy, this view fell into disfavor as a result of the observations of the first and second VACURG studies. Recently, there has been a proliferation of experimental and clinical data supporting early androgen deprivation, including a reanalysis of the VACURG data, which suggests a survival advantage for younger patients with stage D disease and high-grade tumors who undergo androgen-ablative therapy at the time of diagnosis. The risk-benefit analysis presented in this review is strongly supportive of early hormonal therapy. Finally, long-term survival of patients with metastatic prostate cancer will require the development of novel treatment strategies effective against androgen-resistant tumor cells and their use in concert with early androgen deprivation.

Role of transrectal ultrasonography in prostate brachytherapy.

Modern brachytherapy has been made possible by advances in ultrasound technology. This technology allows accurate determination of gland size, determination of the relation to the pubic arch, and real-time placement of the radioactive sources. A thorough familiarity with transrectal ultrasonography thus is required to produce high-quality implants consistently.

Acceptability of an Internet treatment decision support program for men with prostate cancer.

We have implemented a customized Internet decision support system designed to engage men in the decision-making process for the management of localized prostate cancer. The system is delivered to patients in the patient education room of the UWMC Prostate Oncology Center. The system interactively guides the patient through a series of surveys, and delivers multi-media interaction modeling and decision support output, both of which are customized for the patient's preferences. The system is currently implemented on an open source platform.

Repeat prostate needle biopsy: who needs it?

The indications for repeat prostate needle biopsy after a transrectal ultrasound guided sextant biopsy are not defined. We examined 100 sextant prostate needle biopsies without a diagnosis of malignancy, which were repeated. Carcinoma was detected in 20 repeat biopsies (20%). Stratification based on initial biopsy result revealed carcinoma in 10 of 69 cases (14.5%) without prostatic intraepithelial neoplasia or atypia, 5 of 17 (29.4%) with atypia, 5 of 5 (100%) with grade II or III prostatic intraepithelial neoplasia and 0 of 9 with grade I prostatic intraepithelial neoplasia. Examination of prostate specific antigen (PSA) levels and PSA velocity did not provide statistically significant stratification, perhaps due to the wide variance in these parameters and the small sample size. We conclude that patients with a diagnosis of glandular atypia, or grade II or III prostatic intraepithelial neoplasia on initial biopsy are at high risk for invasive carcinoma and should undergo repeat prostate needle biopsy. A rapidly increasing serum PSA level or grossly abnormal digital rectal examination may also indicate carcinoma not discovered on initial biopsy.

The significance of isoechoic prostatic carcinoma.

The diagnosis of prostatic carcinoma is most commonly made today by transrectal ultrasound guided needle biopsy. Often hypoechoic and peripheral zone lesions are the only areas sampled. Recently, we showed that this approach missed a quarter of the cancers that would be detected by a systematic biopsy technique. We term these missed cancers isoechoic carcinomas. We reviewed 1,549 systematic sextant prostate needle biopsies, of which 417 cancers were detected and subdivided into hypoechoic cancers (cancers detected on biopsy of a hypoechoic sector and isoechoic cancers (cancers found only in normal [isoechoic] peripheral zone). We noted in men with only isoechoic cancers that fewer biopsy cores per prostate revealed cancer (mean 1.6 versus 3.0, p < 0.0001) and that these men had lower serum prostate specific antigen levels (mean 14.4 versus 43.7, p < 0.001). The Gleason scores for the isoechoic and hypoechoic cancers were indistinguishable. The pathological staging of hypoechoic and isoechoic cancers was also similar. This study suggests that while isoechoic cancers are generally smaller than hypoechoic cancers, they do not represent low grade clinically insignificant carcinomas. A systematic approach to performing prostate biopsy is recommended.

The relationship between serial measurements of the level of a bladder tumor associated antigen and the potential for recurrence.

PURPOSE: We evaluate the relationship between a serially assessed quantitative diagnostic marker (QDM) and the hazard function for the diagnosis of recurrence of bladder cancer. The marker is based on a bladder tumor associated antigen (BTA TRAK) assay. We present a rigorous approach to the evaluation of diagnostic markers to be used for recurrence monitoring. MATERIALS AND METHODS: Archival voided urine samples serially collected from 187 patients with a prior diagnosis of transitional cell carcinoma of the bladder were measured for BTA TRAK, an assay performed in clinical laboratories. All patients had been treated for stage Ta or T1 transitional cell carcinoma and were undergoing periodic assessments for recurrence. The results from the QDM were not used in case management. Time to histologically confirmed recurrence of transitional cell carcinoma was modeled using proportional hazard regression with the serial measurements of QDM levels and other variables as covariates. QDM levels are in the model as a time dependent covariate on the base 10 logarithmic scale. RESULTS: The estimated hazard ratio for QDM level indicated a 60% increase in the hazard for the diagnosis of recurrence for each 10-fold increment in the marker level (p = 0.013). CONCLUSIONS: A statistically significant relationship between the serially assessed QDM levels and the hazard for the diagnosis of recurrence has been established but the definition of optimum strategies for use of this relationship in clinical practice will require further study. Meanwhile, a prudent action based on the statistical relationship would be to shorten surveillance intervals for patients with high QDM levels.