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Biomedical subjects

C N Robertson

Publications and source records attributed to C N Robertson.

At least 19 recordsLinked to original sources

Timing and patterns of recurrences and deaths from prostate cancer following adjuvant pelvic radiotherapy for pathologic stage T3/4 adenocarcinoma of the prostate.

To determine the timing and patterns of late recurrence after radical prostatectomy (RP) alone or RP plus adjuvant radiotherapy (RT). Between 1970 and 1983, 159 patients underwent RP for newly diagnosed adenocarcinoma of the prostate and were found to have positive surgical margins, extracapsular extension and/or seminal vesicle invasion. Of these, 46 received adjuvant RT and 113 did not. The RT group generally received 45-50 Gy to the whole pelvis, then a boost to the prostate bed (total dose of 55-65 Gy). In the RP group, 62% received neoadjuvant/adjuvant androgen deprivation vs 17% in the RT group. Patients were analyzed with respect to timing and patterns of failure. Only one patient was lost to follow-up. The median follow-up for surviving patients was nearly 20 years. The median time to failure in the surgery group was 7.5 vs 14.7 years in the RT group (P=0.1). Late recurrences were less common in the surgery group than the RT group (9 and 1% at 10 and 15 years, respectively vs 17 and 9%). In contrast to recurrences, nearly half of deaths from prostate cancer occurred more than 10 years after treatment. Deaths from prostate cancer represented 55% of all deaths in these patients. Recurrences beyond 10 years after RP in this group of patients were relatively uncommon. Despite its long natural history, death from prostate cancer was the most common cause of mortality in this population with locally advanced tumors, reflecting the need for more effective therapy.

Adenocarcinoma↗

Synthesis and evaluation of 18F-labeled choline as an oncologic tracer for positron emission tomography: initial findings in prostate cancer.

The up-regulation of rates of choline uptake and phosphorylation in certain malignancies has motivated the development of positron-labeled choline analogues for noninvasive detection of cancer using positron emission tomography (PET). The choline analogue, no-carrier-added [18F]fluoromethyl-dimethyl-2-hydroxyethyl-ammonium (FCH), was synthesized through the intermediate [18F]fluorobromomethane. FCH was evaluated in relationship to 2-[18F]fluoro-2-deoxyglucose (FDG) as an oncological probe in cultured PC-3 human prostate cancer cells, a murine PC-3 human prostate cancer xenograft model, and in PET imaging studies of patients with prostate cancer. FCH was synthesized in 20-40% radiochemical yield and >98% radiochemical purity. Accumulation of FCH and FDG were comparable in cultured prostate cancer cells, whereas only FCH was inhibited (90%) by hemicholinium-3, a specific inhibitor of choline transport and phosphorylation. FCH showed similar biodistribution to [14C]choline in the tumor-bearing mouse, with prominent renal and hepatic uptake. Tumor uptake of FCH was similar to choline and FDG in the mouse model, although tumor:blood ratios were moderately higher for FCH. Initial PET imaging studies in prostate cancer patients showed high uptake of FCH in advanced prostate carcinoma and detection of osseous and soft tissue metastases. FCH uptake by tumors was markedly reduced in patients rescanned during androgen deprivation therapy. It is concluded that FCH closely mimics choline uptake by normal tissues and prostate cancer neoplasms. FCH is potentially useful as a PET tracer for detection and localization of prostate cancer and monitoring effects of therapy.

Aged↗

Pilot study of dietary fat restriction and flaxseed supplementation in men with prostate cancer before surgery: exploring the effects on hormonal levels, prostate-specific antigen, and histopathologic features.

OBJECTIVES: Dietary fat and fiber affect hormonal levels and may influence cancer progression. Flaxseed is a rich source of lignan and omega-3 fatty acids and may thwart prostate cancer. The potential effects of flaxseed may be enhanced with concomitant fat restriction. We undertook a pilot study to explore whether a flaxseed-supplemented, fat-restricted diet could affect the biomarkers of prostatic neoplasia. METHODS: Twenty-five patients with prostate cancer who were awaiting prostatectomy were instructed on a low-fat (20% of kilocalories or less), flaxseed-supplemented (30 g/day) diet. The baseline and follow-up levels of prostate-specific antigen, testosterone, free androgen index, and total serum cholesterol were determined. The tumors of diet-treated patients were compared with those of historic cases (matched by age, race, prostate-specific antigen level at diagnosis, and biopsy Gleason sum) with respect to apoptosis (terminal deoxynucleotidyl transferase [TdT]-mediated dUTP-biotin nick end-labeling [TUNEL]) and proliferation (MIB-1). RESULTS: The average duration on the diet was 34 days (range 21 to 77), during which time significant decreases were observed in total serum cholesterol (201 +/- 39 mg/dL to 174 +/- 42 mg/dL), total testosterone (422 +/- 122 ng/dL to 360 +/- 128 ng/dL), and free androgen index (36.3% +/- 18.9% to 29.3% +/- 16.8%) (all P <0.05). The baseline and follow-up levels of prostate-specific antigen were 8.1 +/- 5.2 ng/mL and 8.5 +/- 7.7 ng/mL, respectively, for the entire sample (P = 0.58); however, among men with Gleason sums of 6 or less (n = 19), the PSA values were 7.1 +/- 3.9 ng/mL and 6.4 +/- 4.1 ng/mL (P = 0.10). The mean proliferation index was 7.4 +/- 7.8 for the historic controls versus 5.0 +/- 4.9 for the diet-treated patients (P = 0.05). The distribution of the apoptotic indexes differed significantly (P = 0.01) between groups, with most historic controls exhibiting TUNEL categorical scores of 0; diet-treated patients largely exhibited scores of 1. Both the proliferation rate and apoptosis were significantly associated with the number of days on the diet (P = 0.049 and P = 0.017, respectively). CONCLUSIONS: These pilot data suggest that a flaxseed-supplemented, fat-restricted diet may affect prostate cancer biology and associated biomarkers. Further study is needed to determine the benefit of this dietary regimen as either a complementary or preventive therapy.

Adult↗

Early onset baldness and prostate cancer risk.

Prostatic carcinoma is the leading cancer among American men, yet few risk factors have been established. Although increased androgen levels have long been associated with both prostatic carcinoma and baldness, to date no studies have shown an association between hair patterning and prostate cancer risk. A lack of standardized instruments to assess baldness or the assessment of hair patterning during uninformative periods of time may have precluded the ability of previous studies to detect an association. We hypothesized that baldness, specifically vertex baldness, should be assessed using standardized instruments and during early adulthood if an association with prostate cancer risk is to be found. To test this hypothesis, we included identical items related to hair patterning in surveys that were administered in two distinct prostate cancer case-control studies (Duke-based study, n = 149; 78 cases; 71 controls and community-based study, n = 130; 56 cases; 74 controls). In each, participants were provided with an illustration of the Hamilton Scale of Baldness and asked to select the diagrams that best represented their hair patterning at age 30 and again at age 40. From these data, the following five categories were created and compared: not bald (referent group); vertex bald early onset (by age 30); vertex bald later onset (by age 40); frontal bald early onset (by age 30); frontal bald later onset (by age 40); and frontal (at age 30) to vertex bald (at age 40). Separate analyses of the two studies are consistent and suggest an association between vertex baldness and prostate cancer [vertex bald early onset odds ratios, 2.44 [confidence interval (CI), 0.57-10.46)] and 2.11 (CI, 0.66-6.73), respectively; vertex bald later onset odds ratios, 2.10 (CI, 0.63-7.00) and 1.37 (CI, 0.47-4.06), respectively]. Although statistical significance was not achieved in either one of these studies, the concordance between the data suggests a need for future studies to determine whether early onset vertex baldness serves as a novel biomarker for prostate cancer and whether androgen production, metabolism, or receptor status differs among these men when compared to those who exhibit other types of hair patterning.

Adenocarcinoma↗

Molecular cytogenetic analysis of the bladder carcinoma cell line BK-10 by spectral karyotyping.

The bladder cancer cell line BK-10 was established from a grade III-IV transitional cell carcinoma (TCC). BK-10 is near-tetraploid (+/-4n) and consists of two subclones with 20-25 structural aberrations. Here we report the cytogenetic analysis of BK-10 by G-banding, spectral karyotyping (SKY), and FISH. SKY refers to the hybridization of 24 differentially labeled chromosome painting probes and the simultaneous visualization of all human chromosomes using spectral imaging. SKY enabled us to confirm 12 markers in BK-10 previously described by G-banding, redefine 11 aberrations, and detect 4 hidden chromosomal rearrangements, 2 of which had been identified as normal or deleted copies of chromosome 20 and 1 as a normal chromosome 3. Twenty out of 21 translocations identified were unbalanced. FISH analysis of BK-10 using chromosome arm-specific paints, centromere probes, and oncogene/tumor suppressor gene-specific probes revealed a deletion of CDKN2A (p16) in all copies of chromosome 9, a low-level amplification of MYC (five copies), and loss of one copy of TP53; detected the presence of the Y chromosome in a hidden translocation; and detected four copies of ERBB-2. A probe set for BCR and ABL verified breakpoints for all translocations involving chromosomes 9 and 22. A new karyotype presentation, "SKY-gram," is introduced by combining data from G-banding, SKY, and FISH analysis. This study demonstrates the approach of combining molecular cytogenetic techniques to characterize fully the multiple complex chromosomal rearrangements found in the bladder cancer cell line BK-10, and to refine the chromosomal breakpoints for all translocations.

Aged↗

Transient lumbosacral polyradiculopathy after prostatectomy: association with spinal stenosis.

Mononeuropathies are common after pelvic surgery. They are usually the result of unnatural positioning during surgery or faulty restraining devices. Polyneuropathy in the postoperative setting is rare. We report two cases of polyradiculopathy after radical prostatectomy using two different patient positions. Both patients complained of paresthesias and weakness in their lower extremities on postoperative day 1. Neurologic examination in each case was consistent with a polyradiculopathy. Significant spinal stenosis of the lumbosacral spine was found in both patients by magnetic resonance imaging. We propose that spinal stenosis is a risk factor for this type of neurologic injury.

Anti-Inflammatory Agents↗

QOL and outcomes research in prostate cancer patients with low socioeconomic status.

The VA Cancer of the Prostate Outcomes Study (VA CaPOS) is collecting quality-of-life (QOL) information from prostate cancer patients, spouses, and physicians at six VA medical centers. Currently, 601 men with prostate cancer are included in the study, most of whom are of low socioeconomic status and over half of whom are African-American. Quality-of-life responses were most favorable for newly diagnosed patients, intermediate for those with stable metastatic disease, and poorest for those with progressive metastatic disease. Patients could not provide reliable estimates of their own preferences for future QOL states but responded reliably to questions phrased as a comparison of the preferences of two hypothetical patients. High out-of-pocket costs for hormonal therapies, lack of health insurance, and a belief that the non-VA system offered poorer services were the most common reasons for patient transferral to the VA system. Satisfaction with medical care was generally high. While African-American patients were more likely to have advanced prostate cancer at diagnosis, after adjustment for differences in health literacy, race was no longer a significant predictor of advanced disease. The VA CaPOS provides useful information on health status and patient satisfaction of VA prostate cancer patients. Long-term evaluations are needed to detect clinically meaningful QOL information as the disease progresses.

Adult↗

Peptidyl membrane-interactive molecules are cytotoxic to prostatic cancer cells in vitro.

Cytotoxic membrane disruption via lytic peptides is a well-recognized mechanism of immune surveillance for antifungal and antibacterial host protection. Naturally occurring lytic peptides were shown to exhibit antitumor activity as well. Peptidyl membrane-interactive molecules (MIMs) are synthetic lytic peptides specifically designed to maximize antitumor activity. We tested nine novel Peptidyl MIMs for activity against four androgen-insensitive prostate-cancer cell lines using a standard microculture tetrazolium (MTT) assay. Five Peptidyl MIMs known to form alpha-helical secondary structures were active against prostate carcinoma and were chosen for further study. Three peptides configured in beta-pleated sheets were noticeably less effective. Concentrations lethal to 50% of the prostate-cancer cell lines treated (D50 values) with the five chosen Peptidyl MIMs ranged from 0.6 to 1.8 microM. For comparison, two alpha-helically structured peptides, D2A21 and DP1E, were tested on several other cancer types: breast (n = 2), colon (n = 2). bladder, cervical and lung carcinomas (n = 1 each). Resulting LD50 values obtained in breast carcinoma cells were significantly higher (P < 0.05) than those observed in prostate cancer cells. LD50 values recorded for D2A21 and DP1E in cervical, colon, bladder, and lung cancer lines were similar to those obtained in prostate cancer cells. As compared with cisplatin, a standard chemotherapeutic drug, the LD50 values recorded for D2A21 were significantly lower (P < 0.04) in prostate-cancer cell lines, suggesting the therapeutic efficacy of Peptidyl MIMs. These data demonstrate for the first time the cytotoxic potential of Peptidyl MIMs against prostate cancer cells and suggest a dependence on a specific secondary alpha-helical structure of the peptide.

Adenocarcinoma↗

Does prostate transitional cell carcinoma preclude orthotopic bladder reconstruction after radical cystoprostatectomy for bladder cancer?

PURPOSE: We determined if urethral preservation and orthotopic bladder replacement in patients with transitional cell carcinoma within the prostatic urethra or prostate placed these patients at risk for urethral recurrence or death. MATERIALS AND METHODS: The clinical course of all patients undergoing urethral preservation and orthotopic bladder replacement was reviewed. The urethra was sacrificed only if the distal prostatic urethral margin was positive for transitional cell carcinoma. The pathological T stage and the grade of the primary malignancy, local recurrence, site of recurrence (urethral, pelvic, distant) and death were documented. RESULTS: Of 81 patients 70 were evaluable (June 1996) with a mean followup of 35 months. Of the 70 patients 48 were alive without evidence of disease for a mean of 38 months (range 8 to 107) and 5 died without evidence of disease. Eight of these 53 patients (15%) had prostatic involvement (carcinoma in situ in 6, intraductal carcinoma in 1 and stromal invasive transitional cell carcinoma in 1). Of the 70 patients 17 had disease recurrence (13 died of disease and 4 are alive, 1 of whom had urethral recurrence without initial prostatic transitional cell carcinoma). Of the 17 patients (35%) 6 had transitional cell carcinoma prostatic involvement (carcinoma in situ in 4 and stromal invasion in 2), and 5 of these 6 died, none with or of urethral recurrence but of the primary bladder pathology. Of these 5 patients 1 had stromal invasive transitional cell carcinoma of the prostate and experienced a bulbar urethra recurrence at 1 month and a pelvic recurrence at 3 months, and died at 5 months. Death was not secondary to the urethral recurrence. Thus, of the 14 patients who had prostatic transitional cell carcinoma, only 1 had urethral recurrence (7%), and this recurrence did not present as the cause of death. CONCLUSIONS: The guidelines for urethral resection can be relaxed, increasing the opportunities for orthotopic reconstruction, without placing the patients at increased risk for death of transitional cell carcinoma.

Aged↗

Anthropometric risk factors for prostate cancer.

Cancer of the prostate is the leading cancer among American men, yet few risk factors are known. Anthropometry may help uncover potential risk factors for prostate cancer, since fat distribution, skeletal structure, and musculature may differ between men with this hormonally linked cancer and those without it. A case-control study was undertaken to determine whether anthropometric differences exist between prostate cancer cases and controls and whether such differences are associated with specific hormonal profiles. The study accrued 315 men stratified for race, age, and case/control status. Weight, height (sitting/standing), skinfold thicknesses (triceps, biceps, subscapular, suprailiac, thigh), circumferences (midarm, waist, hip, thigh), breadths (elbow, biacromial, biiliac), hormonal levels (total and free testosterone, dihydrotestosterone, sex hormone-binding globulin), bone density, and body composition were measured. Measures of upper body robustness [i.e., biacromial breadth-to-height ratio (p = 0.02) and biacromial (p = 0.05) and bideltoid (p = 0.04) breadths] were greater among controls. Strong negative associations were found uniformly between sex hormone-binding globulin levels and measures of body adiposity and musculature. Data show that prostate cancer cases exhibit a propensity toward a slight upper body skeleton, which may in itself serve as a risk factor or provide a benchmark of past nutritional and/or hormonal status and help elucidate the etiology of this disease.

Aged↗

Fenretinide: induction of apoptosis and endogenous transforming growth factor beta in PC-3 prostate cancer cells.

N-(4-Hydroxyphenyl)retinamide (4-HPR, Fenretinide) is a retinoid derivative with antineoplastic activity in various tumor types including prostate carcinoma. The mechanism of action of 4-HPR toxicity is unknown. 4-HPR induces apoptosis in leukemia- and lymphoma-derived cells, neuroblastoma, and small cell lung cancers. The present study was designed to investigate: (a) the mechanism of 4-HPR cytotoxicity in prostate cancer cells; and (b) correlate increased expression of transforming growth factor beta 1 (TGF beta 1) with induction of apoptosis. 4-HPR exposure to PC-3 cells in vitro was associated with apoptosis as evidenced by increased incidence of hypodiploid nuclei in propidium iodide fluorescence histograms and DNA fragmentation. An increase in the percentage of nuclei in the G1 phase of the cell cycle preceded induction of apoptosis. TGF beta 1-increased expression was noted in mRNA levels and in secretion of active TGF beta 1 into culture media. TGF beta 1 and TGF-beta receptor type II detected immunohistochemically were increased in 4-HPR-treated PC-3 cells. Furthermore, 4-HPR-induced cytotoxicity in PC-3 cells was abrogated by the addition of anti-TGF beta 1 antibody. In BT-20 cells, a 4-HPR-resistant breast carcinoma cell line, apoptosis was not observed after exposure to 4-HPR nor was TGF beta 1 expression enhanced in stained cells or in conditioned media. It is concluded that 4-HPR induces the expression of TGF beta 1 in association with the induction of apoptosis.

Antineoplastic Agents↗

Induction of apoptosis by diethylstilbestrol in hormone-insensitive prostate cancer cells.

BACKGROUND: Diethylstillbestrol (DES) and diethylstilbestrol diphosphate (DESdP) are effective agents for the treatment of advanced prostate cancers. Tumor-inhibiting effects of DES and DESdP are presumed secondary to suppression of androgen production in vivo. Little is known, however, about the direct cellular mechanisms of the tumor inhibition. Estrogens have been reported not only to stimulate growth but also to disrupt microtubule formation in prostate cancer cells. PURPOSE: The study was designed to examine and compare mechanisms of in vitro growth inhibition of DES and DESdP in human androgen-insensitive prostate cancer cells (DU145, 1-LN, and PC-3) and human androgen-sensitive prostate cancer cells (LNCaP) and to examine estrogen receptor modulation of such effects. METHODS: The cytotoxic effects of DES and DESdP were examined in vitro by use of a standard microculture tetrazolium assay to quantitate numbers of viable cells. Immunofluorescence microscopy, DNA fragmentation analysis, and fluorescence flow cytometry were used to investigate microtubules, the induction of apoptosis, and changes in cell cycle distribution. The degree of estrogen receptor positivity of untreated and treated cells was determined by immunohistochemistry and quantitative image analysis. RESULTS: LD50 levels (the dose at which 50% of cells are no longer viable) in the concentration range of 19-25 microM were observed for both DES and DESdP in all cell lines examined. DESdP-induced growth inhibition was found to be dependent on heat-labile phosphatases present in fetal calf serum. DES-induced cytotoxicity was not affected by the presence of 17 beta-estradiol, and it was not dependent on the presence of estrogen receptor. Estrogen receptor-positive cells and estrogen receptor-negative cells were equally responsive to DES. PC-3 cells stained with fluorescent anti-tubulin, phalloidin (actin stain), and 4',6-diamidino-2-phenylindole (DNA stain) showed no inhibition of microtubules or actin filaments but revealed the presence of apoptotic bodies in the nuclei. Fluorescence flow cytometry of nuclear DNA content of propidium iodide-stained nuclei from androgen-insensitive prostate cancer cells treated with 15 or 30 microM DES or DESdP revealed an increase in relative numbers of hypodiploid (apoptotic) nuclei, a depletion of G1- and S-phase cells, and an accumulation of cells in G2/M phase. Conversely, androgen-sensitive cells contained a lower percentage of hypodiploid nuclei but no accumulation of cells in G2/M phase. CONCLUSIONS: Direct cytotoxic effects of DES in prostate cancer cells are estrogen receptor independent and do not involve disruption of microtubule architecture but do involve the promotion of cell cycle arrest and apoptosis. These are the first data confirming direct cytotoxic effects of DES and DESdP in prostate cancer cells via an apoptotic mechanism. IMPLICATIONS. These results suggest that DES and DESdP have potential value as agents against androgen-insensitive prostate neoplasms through induction of an apoptotic cascade.

Antineoplastic Agents, Hormonal↗

Glutathione and glutathione S-transferase in benign and malignant prostate cell lines and prostate tissues.

Metastatic prostate adenocarcinoma is unresponsive to alkylator chemotherapy with virtually no prolonged remissions. Glutathione (GSH) and glutathione S-transferase (GST) have been reported to play a role in tumor resistance to alkylator therapy; however, there are no baseline studies that have investigated and compared GSH and GST in human prostate cell lines and tissues. Thus, we determined the GSH content and GST activity in benign prostate, in primary and metastatic prostate adenocarcinoma tissues, in immortal adenocarcinoma cell lines, and in primary cell cultures derived from both benign prostate and primary prostatic carcinoma tissue. The GSH content was higher in the immortal cell lines than in the fresh tissues and primary cultures. Conversely, the GST activity was significantly higher in the tissues and primary cultures than in the cell lines. The GSH content and GST activity of the primary cultured prostatic cells were similar to those of the prostate tissues. The differences between the immortal prostate cancer cell lines and prostate tissue are of sufficient magnitude to suggest that in vitro results with cell lines may not extrapolate to prostate cancer in vivo. The GSH content and GST activity in a prostate specific antigen-secreting human prostate tumor xenograft, LuCaP23, maintained in nude mice were similar to those of human prostate tissue and primary cultures. Both the xenograft and primary cultures from patients with prostate cancer may be more appropriate models than established cell lines for investigating techniques to increase the effectiveness of alkylators in prostate cancer.

Adenocarcinoma↗

Correlation of DNA ploidy and histologic diagnosis from prostate core-needle biopsies: is DNA ploidy more sensitive than histology for the diagnosis of carcinoma in small specimens?

DNA ploidy has been shown to have prognostic value in adenocarcinoma of the prostate. While occasional benign lesions of the prostate may be associated with a DNA aneuploid status, most aneuploid epithelial proliferations of the prostate are carcinomas. Because of the relationship between aneuploidy and malignancy, DNA ploidy analysis might improve detection of adenocarcinoma in small core-needle biopsy specimens. In this study, DNA ploidy analysis was performed on 186 fresh core biopsies from 32 patients who had undergone transrectal, ultrasonographically directed core-needle biopsies. Ploidy level was determined by Feulgen staining and image analysis with a CAS 200 image analyzer (Becton Dickinson-Cellular Imaging Systems, San Jose, CA). The resultant DNA ploidy levels were compared with the initial histologic diagnosis and subsequent clinical and pathologic follow-up. Nondiploid DNA patterns correlated with a diagnosis of carcinoma on core biopsy in 11 of 16 nondiploid cases and with a final diagnosis of malignancy in 13 of 16 nondiploid cases. Two patients with biopsy proven carcinoma had DNA diploid tumor patterns. Ploidy analysis had a sensitivity of 86.6% and a specificity of 73.7% in predicting the final diagnosis of malignancy. One case interpreted as DNA tetraploid by image analysis revealed seminal vesicle tissue on both the cytologic preparations and the core biopsy. Two DNA aneuploid specimen associated with cores initially read as benign or atypical demonstrated adenocarcinoma either on review of the original core biopsy or the prostatectomy specimen. The final DNA aneuploid specimen revealed acute prostatitis in the core biopsy. DNA ploidy analysis of core biopsy specimens appears to have relatively good specificity and sensitivity for the detection of prostatic carcinoma. Sampling errors appear to be the major cause of false negative results. Inappropriate measurement of seminal vesicle tissue and acute prostatitis can result in false positive results.

Adenocarcinoma↗

Adjuvant radiotherapy for pathologic stage T3/4 adenocarcinoma of the prostate: ten-year update.

PURPOSE: To determine the role of adjuvant postoperative radiotherapy (RT) following radical prostatectomy (RP) in a group of patients with pathologic Stage T3/4 adenocarcinoma of the prostate followed for a median of 10 years after treatment. METHODS AND MATERIALS: Between 1970 and 1983, 159 patients underwent RP for newly diagnosed adenocarcinoma of the prostate and were found to have pathologic Stage T3/4. Forty-six received adjuvant RT and 113 did not. Radiotherapy usually consisted of 45-50 Gy to the whole pelvis followed by a boost to the prostate bed of 10-15 Gy, to a total dose of 55-65 Gy. Patients were analyzed with respect to survival, disease-free survival, local control, and freedom from distant metastases. A rising prostate-specific antigen in the absence of other evidence of relapse was scored as a separate category of recurrence. RESULTS: Both groups of patients have been followed for a median of 10 years. The actuarial survival at 10 and 15 years was 62% and 62% for the RT group compared to 52% and 37%, respectively, for the RP group (p = 0.18). The disease-free survival for the Rt group was 55% and 48% at 10 and 15 years, respectively, compared to 37% and 33% for the RP group (p = 0.16). Similarly, there was no difference in the rate of distant metastases between the two groups. In contrast, the local relapse rate was significantly reduced by the addition of postoperative radiotherapy. The actuarial local control rate at 10 and 15 years was 92% and 82%, respectively, for the RT group vs 60% and 53% for the RP group (p = 0.002). CONCLUSIONS: While postoperative pelvic RT significantly improves local control compared to RP alone for pathologic Stage T3/4 prostate cancer, it has no impact on distant metastases and consequently does not improve survival. These data are consistent with the conclusion that many patients with pathologic Stage T3/4 prostate cancer have occult metastases at presentation and will not be cured by local therapies alone. The optimal treatment for this patient population remains to be established.

Adult↗

6-Methylene progesterone is cytotoxic to human cancer cell lines independent of its 5-alpha-reductase activity.

This investigation examined the effects of 6-methylene progesterone (6MP), an irreversible inhibitor of 5-alpha-reductase, on prostatic cancer (PC) cell lines. Dose titration microculture tetrazolium assays were used to evaluate cytotoxicity in cultures treated for 72 hr with 6MP (0-20 micrograms/ml). An androgen-sensitive cell line, LNCaP, was drug-sensitive with a mean 50% lethal dose value (LD50) of 2.632 +/- 0.103. Hormone-resistant PC cell lines 1-LN, DU 145, and PC3 also demonstrated sensitivity with LD50 values between 0.8579-1.110 micrograms/ml with a group average of 1.023 +/- 0.082 micrograms/ml. Increasing dosages of dihydrotestosterone in the growth media did not alter 6MP cytotoxicity in androgen-insensitive prostatic cancer cell lines. No correlation between androgen-responsiveness and 6MP-induced cytotoxicity was observed. In nonprostatic malignancies, 6MP inhibited adenocarcinoma cell lines with a mean group LD50 value of 0.7772 micrograms/ml +/- 0.110. J82, a transitional cell carcinoma cell line of bladder origin, exhibited an average LD50 value of 1.041 +/- 0.260. In an epidermoid cervical cancer cell line, ME180, an LD50 value of 0.5356 micrograms/ml +/- 0.010 was noted. In a melanoma cell line, Du Mel 6, a mean LD50 of 0.7428 +/- 0.023 micrograms/ml was achieved with 6MP. We conclude that 6MP, a novel 5-alpha-reductase inhibitor, has potential as a cytotoxic agent in prostatic carcinoma and additional human malignancies. Further study is justified.

Cholestenone 5 alpha-Reductase↗

Isolation and characterization of a novel human prostatic stromal cell culture: DuK50.

A novel human prostatic stromal cell culture, designated DuK50, has been passed in vitro > 12 mo. Tissue cultures were obtained from material harvested within a normal region of a radical prostatectomy specimen. These monolayers exhibited normal fibroblastic characteristics with each cell having a flattened, elongated appearance. Karyotypic analysis revealed a normal, male 46, XY chromosomal content with no numerical or structural abnormalities. DNA analysis using a Cell Analysis Systems Image Analyzer confirmed a euploid DNA content (7.9 pg DNA). Cellular markers for verification of stromal cell type were performed by immunohistochemical techniques. DuK50 stained positive for vimentin and fibronectin. Immunostains for epithelial cytokeratins and prostate-specific antigen were negative, which ruled out contamination with prostatic epithelial cells. Negative immunostaining with desmin monoclonal antibody and light staining with smooth muscle actin alpha is consistent with the staining pattern of myofibroblasts. Response to various androgens, measured by a microculture tetrazolium assay technique, revealed a significant growth stimulation of DuK50. Soft agar invasiveness assays and tumorigenicity studies in nude mice were negative. DuK50 exhibits a rapid doubling time with excellent plating efficiency, thrives in a readily available media supplemented with fetal bovine serum, and passes with routine trypsin protocols. The availability of this prostatic stromal cell culture may facilitate studies on this cell type's role in growth factor modulation, drug and steroid metabolism, and stromal-epithelial interactions in the prostate.

Aged↗