Rat astrocytic tumour cells are associated with an anti-inflammatory microglial phenotype in an organotypic model.

AIM: Microglia form a high proportion of cells in glial tumours but their role in supporting or inhibiting tumour growth is unclear. Here we describe the establishment of an in vitro model to investigate their role in astrocytomas. METHODS: Rat hippocampal slices were prepared and, after 7 days to allow microglia to become quiescent, rat C6 astrocytic tumour cells were added. Over the following 7 days, infiltration and cell death were studied using fluorescent C6 tumour cells and confocal microscopy; immunophenotyping of microglia was performed using CD68 (phagocytosis), MHCII (antigen-presentation) and Iba1 (microglial marker regardless of functional state). Cell proliferation was assessed using Ki67 and qPCR to detect cytokine expression. Sham and control groups were included. RESULTS: Microscopy showed proliferation of C6 tumour cells with both infiltration of tumour cells into the hippocampal tissue and of microglia among the tumour cells. Confocal experiments confirmed increasing tumour cell infiltration into the hippocampal slice with time (P<0.001), associated with cell death (σ=0.313, P=0.022). Ki67 showed increased proliferation (P<0.001), of both tumour cells and Iba1+ microglia and increased microglial phagocytosis (CD68: P<0.001). Expression of pro-inflammatory cytokines IL1, IL6 and TNFα were downregulated with expression of the anti-inflammatory cytokine TGFß1 maintained. CONCLUSION: This model allows study of the proliferation and infiltration of astrocytic tumour cells in central nervous system tissue and their interaction with microglia. Our data suggest that microglial function is altered in the presence of tumour cells, putatively facilitating tumour progression. Manipulation of the microglial functional state may have therapeutic value for astrocytic tumours.

A randomized trial comparing heater probe plus thrombin with heater probe plus placebo for bleeding peptic ulcer.

BACKGROUND & AIMS: This multicenter, double-blind, controlled trial compared the efficacy of combined endoscopic hemostatic treatment using the heater probe plus thrombin injection with that of the heater probe plus placebo injection as treatment for peptic ulcers with active bleeding or nonbleeding visible vessels. Efficacy was defined in terms of primary hemostasis, prevention of rebleeding, and need for urgent surgery. METHODS: Two hundred forty-seven patients presenting with major peptic ulcer bleeding were randomized to heater probe plus thrombin or to heater probe plus placebo. The groups were well matched for all risk categories including age, endoscopic stigmata, shock, and severity of comorbid diseases. Endoscopic therapy was applied using the heater probe followed by injection of thrombin or placebo. RESULTS: Successful primary hemostasis was achieved in 97% of patients. Rebleeding developed in 19 (15%) of thrombin plus heater probe patients and 17 (15%) of placebo plus heater probe patients. Emergency surgery was necessary in 16 and 13 patients, respectively. Eight patients in the thrombin group had adverse events compared with 4 in the placebo group. Eight (6%) of thrombin plus heater probe patients and 14 (12%) of placebo plus heater probe patients died (P = 0.21). CONCLUSIONS: The combination of thrombin and the heater probe does not confer an additional benefit over heater probe and placebo as endoscopic treatment for bleeding peptic ulcer. Our trial does not support the use of this combination of hemostatic therapy.

The changing spectrum of gastroesophageal reflux disease.

The incidences of Barrett's oesophagus and oesophageal adenocarcinoma are rising. However there is no evidence on whether the incidence of gastroesophageal reflux disease is rising. This was a retrospective study investigating the incidence of gastroesophageal reflux disease at endoscopy from 1980 to 1995. The study took place in Tayside, Scotland. Using the Tayside endoscopy database, patients with new diagnoses of Barrett's oesophagus and endoscopic oesophagitis were identified. Cases and rates (per 1000 endoscopies) for oesophagitis, Barrett's oesophagus and combined group of oesophagitis + Barrett's oesophagus were calculated for each year. There was a significant decline in the incidence of oesophagitis. There was a significant large increase in the incidence of Barrett's oesophagus and a small but significant rise in the incidence of endoscopically identified gastroesophageal reflux disease (oesophagitis + Barrett's oesophagus). There was a significant decrease in the ratio of new cases of oesophagitis to new cases of Barrett's oesophagus. At endoscopy there has been a small increase in incidence of gastroesophageal reflux disease. There has, however, been a dramatic change in the spectrum of gastroesophageal reflux disease, with a larger proportion having Barrett's oesophagus than previously.

A natural history of cleidocranial dysplasia.

Cleidocranial dysplasia (CCD) is an autosomal dominant skeletal dysplasia associated with clavicle hypoplasia and dental abnormalities. The condition is caused by mutations in the CBFA1 gene, a transcription factor that activates osteoblast differentiation. Clinical characteristics associated with CCD have previously been described in case reports and small case series. This study was undertaken to gain a more complete delineation of clinical complications associated with CCD. The study population was composed of 90 CCD individuals and 56 relative controls ascertained from genetic and dental practices in the United States, Canada, Europe, and Australia. A number of previously unrecognized complications were significantly increased including: genua valga, scoliosis, pes planus, sinus infections, upper respiratory complications, recurrent otitis media, and hearing loss. Primary Cesarean section rate was significantly increased compared to relative controls and the general population rate. Finally, dental abnormalities, including supernumerary teeth, failure of exfoliation of the primary dentition, and malocclusion, are serious and complex problems that require intervention. Clinical recommendations based on the results of this study are included.

Quantification of histochemical staining by color deconvolution.

OBJECTIVE: To develop a flexible method of separation and quantification of immunohistochemical staining by means of color image analysis. STUDY DESIGN: An algorithm was developed to deconvolve the color information acquired with red-green-blue (RGB) cameras and to calculate the contribution of each of the applied stains based on stain-specific RGB absorption. The algorithm was tested using different combinations of diaminobenzidine, hematoxylin and eosin at different staining levels. RESULTS: Quantification of the different stains was not significantly influenced by the combination of multiple stains in a single sample. The color deconvolution algorithm resulted in comparable quantification independent of the stain combinations as long as the histochemical procedures did not influence the amount of stain in the sample due to bleaching because of stain solubility and saturation of staining was prevented. CONCLUSION: This image analysis algorithm provides a robust and flexible method for objective immunohistochemical analysis of samples stained with up to three different stains using a laboratory microscope, standard RGB camera setup and the public domain program NIH Image.

Chromosomal imbalances in gastric and esophageal adenocarcinoma: specific comparative genomic hybridization-detected abnormalities segregate with junctional adenocarcinomas.

The incidence of adenocarcinoma arising at the esophagogastric junction (EGJ) is increasing at a rate greater than that for any other form of solid malignancy. Commensurate with this, the incidence of histologically similar tumors arising in the gastric body and antral mucosa is declining. The increased incidence of the proximal group of tumors may reflect, in part, the higher prevalence of Barrett esophagus. These epidemiological features suggest that histologically similar tumors arising at the EGJ and from the distal stomach are different, which may be reflected in the genetic abnormalities that characterize the two groups of tumors. The purpose of this study was to screen genomic DNA from adenocarcinomas of the esophagus and stomach for regions of chromosomal imbalance, using comparative genomic hybridization to determine whether tumors at the EGJ (junctional tumors) have a different profile compared with tumors of the distal stomach. Tumor samples were derived from a series of 48 gastroesophageal adenocarcinomas (20 junctional and 28 distal) that were acquired prospectively from patients undergoing esophagogastrectomy. These tumors are characterized by several regions of chromosomal imbalance with no obvious correlation between most regions of abnormal copy number and tumor type. However, our study shows for the first time cytogenetic abnormalities (5p+ and 18q-) that identify statistically significant differences (P < 0.02 and < 0.05, respectively) between junctional and distal gastric tumors. These differences are gain of 5p (55% [11/20] of junctional tumors vs. 21% [6/28] of distal gastric tumors) and loss of 18q (25% [5/20] cases of junctional tumors vs. 4% [1/28] of distal tumors) segregating with tumors of the EGJ. These abnormalities may distinguish distinct tumor subtypes that are recognized in epidemiological and clinical studies but that are otherwise histologically identical.

Can complexed prostate specific antigen and prostatic volume enhance prostate cancer detection in men with total prostate specific antigen between 2.5 and 4.0 ng./ml.

PURPOSE: We assessed whether complexed prostate specific antigen (PSA) and complexed PSA referenced variables would enhance prostate cancer detection in men with serum total PSA between 2.5 and 4.0 ng./ml. MATERIALS AND METHODS: Transition zone and total prostate gland volumes were determined in 151 men who underwent prostate biopsy using an 11 core biopsy strategy. In addition to measuring the Bayer section sign complexed PSA assay, we also calculated 2 computed complexed PSA values (Hybritech parallel total PSA--Hybritech free PSA and Bayer total PSA--Hybritech free PSA). We calculated 8 volume referenced variables using total and complexed PSA, and 2 computed complexed PSA values by dividing each value by the total prostate and transition zone volumes. RESULTS: Of the 151 patients 37 (24.5%) had cancer. In 10 of the 37 men with cancer (27%) a positive core was present in only 1 or more of the 5 alternate regions not sampled by conventional sextant biopsies. At 92% sensitivity a cutoff value of 2.3 ng./ml. for complexed and 31% for free-to-total PSA provided 42% and 11% specificity, respectively (p <0.001). In the 116 men with a total prostate volume of 30 cc or greater at 92% sensitivity the specificity of complexed PSA density (55%) and complexed PSA adjusted for transition zone volume (52%) were better than that of complexed (40%) and free-to-total (11%) PSA. In the 35 men with a total prostate volume of less than 30 cc at 92% sensitivity the specificity of complexed PSA (50%), complexed PSA density (55%) and complexed PSA adjusted for transition zone volume (55%) were significantly better than that of free-to-total PSA (8%, p <0.001). The area under the curve of complexed PSA was almost identical to that of the 2 computed complexed PSA calculations. CONCLUSIONS: A substantial proportion of men with total PSA values between 2.5 and 4.0 ng./ml. had prostate cancer. Complexed and computed complexed PSA were more specific than the free-to-total PSA ratio when total PSA was between 2.5 and 4.0 ng./ml. A 2.3 ng./ml. threshold for complexed and computed complexed PSA appears to stratify prostate biopsy results in men with total PSA between 2.5 and 4.0 ng./ml. The computed complexed PSA calculation appears to be equivalent to the complexed PSA serum assay for detecting cancer. Volume referenced complexed PSA performed better than complexed PSA in men with a total prostate volume of 30 cc or greater compared to men with a total prostate volume of less than 30 cc.

Analysis of clinicopathologic factors predicting outcome after radical prostatectomy.

BACKGROUND: A variable biochemical failure rate has been reported for patients undergoing radical prostatectomy. The authors analyzed their 1987-1993 prostatectomy experience retrospectively to stratify the risk of failure in order to appropriately select patients who potentially may benefit from adjuvant therapy. METHODS: A stepwise logistic regression was used to identify variables associated with biochemical failure in 265 patients who underwent radical prostatectomy only. Prostate tumors were examined by one pathologist using 4-mm step sections. Numerous clinicopathologic variables were evaluated, and the neoplasms were subclassified into five pathologic categories based on tumor extent and margin status. Actuarial projections of biochemical failure were created using the Kaplan-Meier method. RESULTS: Pathologically, 56.2% of the tumors were organ-confined with negative margins, 12.8% had a positive surgical margin without evidence of extraprostatic extension (EPE), 24.2% had EPE (17% with negative margins and 7.2% with positive margins), and 6.8% had seminal vesicle involvement. The Gleason score was > or = 7 in 86.4% of the total population. Values for the preoperative prostate specific antigen assay were < or = 4.0 ng/mL in 23.4% of the men and > 10 ng/mL in 27.7%. The overall observed biochemical failure rate in this patient group with a minimum 48 months of follow-up was 15.5%. Overall, stepwise logistic regression analysis revealed that pathologic category was the variable most strongly associated with biochemical failure and that vascular invasion was the only other examined variable associated with failure. CONCLUSIONS: The combination of pathologic category and the prostatectomy Gleason score can stratify a patient's probability of biochemical failure into three distinct groups and can identify the appropriate patients who may benefit from novel adjuvant therapeutic strategies.

The incidence of prostate cancer in a screening population with a serum prostate specific antigen between 2.5 and 4.0 ng/ml: relation to biopsy strategy.

PURPOSE: It has recently been suggested that the diagnostic threshold for the prostate specific antigen (PSA) assay be lowered to enhance prostate cancer detection. A 22% incidence of prostate cancer has been reported in men with PSA between 2.5 and 4.0 ng/ml. We designed a study to confirm this observation. MATERIALS AND METHODS: Men who participated in our free early detection program and who had serum PSA between 2.5 and 4.0 ng/ml were asked to undergo prostate biopsy. Of 268 eligible men 151 (56%) agreed to participate in this free trial. All men underwent biopsy using an 11-core multisite directed biopsy scheme. All biopsy cores were color coded for location specificity and examined by 1 pathologist. RESULTS: Cancer was identified in 24.5% (37 of 151) of the men biopsied. The median age of men with cancer was 62 years (range 43 to 74). Conventional systematic sextant biopsies, which accounted for 6 of the 11 cores, detected 73.0% (27 of 37) of the cancers and the alternate site biopsies identified the remaining 10. Gleason score was 6 in 25 men, 3 + 4 in 5, 4 + 3 in 4 and 8 or greater in 3 (median Gleason score 6). There were 14 men who had 1 core positive for cancer, 9 had 2 and 14 had more than 2 (median number of positive cores 2). Of the 14 men with 1 positive core 11 had a less than 3 mm focus of cancer and 8 had only a positive alternate site biopsy. There were 11 cases of abnormal results on digital rectal examination, 5 of which were cancer, and 31 cases of abnormal results on ultrasonography, 13 of which were cancer. Median biological variability in PSA was +/-15% (range 0.4% to 440.0%). CONCLUSIONS: We found a significant incidence of cancer (24.5%, 37 of 51) in men with serum PSA between 2.5 and 4.0 ng/ml. In our study 67.6% of the detected cancers were significant based on the biopsy data. If the PSA threshold is lowered the conventional systematic sextant technique may be preferable to an extended strategy.

The prescribing of acid suppressants prior to the endoscopic diagnosis of Barrett's oesophagus and oesophagitis.

BACKGROUND: There has been a dramatic rise in incidences of Barrett's oesophagus and oesophageal adenocarcinoma. It has been suggested that the introduction and use of acid suppression therapy may be a factor in the rising incidences of Barrett's oesophagus and oesophageal adenocarcinoma. METHODS: This was a record linkage study, using a prescribing database and an endoscopy database. Patients who had undergone their first endoscopy during the period 1992-1995 and received the diagnosis of Barrett's oesophagus or oesophagitis were identified. The prescribing of acid suppressants was compared for the 3 years prior to endoscopy, between those with Barrett's oesophagus and those with oesophagitis. RESULTS: There was no significant difference between the Barrett's patients and the oesophagitis patients in the proportion that had been exposed to acid suppression therapy (53.4% vs. 51.7%, P=0.704). The mean number of days of prescribing among those who had been exposed to acid suppression therapy was higher in the Barrett's group (340.5 vs. 237.0 days, P=0.001). CONCLUSIONS: Patients with Barrett's oesophagus have received more acid suppressant therapy prior to diagnosis. The reasons for this are not clear. However, 46.6% of Barrett's patients have not been exposed to acid suppressant therapy.

Elevated expression of hepatic proliferative markers during early hepatocarcinogenesis in hepatitis-B virus transgenic mice lacking mdr1a-encoded P-glycoprotein.

Recent studies have shown that expression levels of the multidrug resistance gene MDR1, which encodes the drug transporter P-glycoprotein, correlate with prognostic outcomes of certain tumor types. These findings suggest that expression of MDR1 may affect tumor behaviors. To address this issue further, we investigated the expression of mdr1a, a human MDR1 homolog, on the development of hepatocellular carcinoma in a transgenic mouse model carrying the liver-targeted expression of human hepatitis-B virus (HBV) surface antigen. The pathogenetic program was compared in HBV mice carrying either mdr1a(+/+) or mdr1a(-/-). We found that the expressions of proliferative activity markers, Ki67 nuclear antigen, and proliferating cell nuclear antigen were elevated in mdr1a(-/-) mice younger than 10 wk in comparison with those in the same age group of wild-type animals. Replication in the hepatic population as determined by bromodeoxyuridine incorporation tended to support observation that mdr1a(-/-) mice exhibited elevated labeling indices in this age group. Moreover, histologic staining and flow-cytometric analysis showed that the mdr1a(-/-) animals exhibited a higher cell population with polyploidy than did the mdr1a(+/+) counterparts of the same age. However, no significant differences in the expression of the liver-injury markers serum alanine transaminase and aspartate transaminase were observed. Although our results showed that absence of mdr1a expression is correlated with modest enhanced proliferative characteristics in the livers at stage before the development of hepatocellular carcinoma, the overall life spans between these two strains of mice were not significantly different. The implication of these findings to the role of P-glycoprotein in tumor development and cancer chemotherapy is discussed.

Detailed mapping of prostate carcinoma foci: biopsy strategy implications.

BACKGROUND: Prostate carcinoma exhibits considerable anatomic heterogeneity. Detailed characterization of prostate carcinoma distribution could lead to improved detection procedures and biopsy strategies. We mapped all 607 tumor foci from 180 serially sectioned whole mount radical prostatectomy specimens and used a computer algorithm to plot and summarize the distribution of these foci. We investigated whether specimen and clinical variables predicted differences in tumor distribution. METHODS: The volume and anatomic location of each tumor focus were determined and digitized. A computer-based algorithm was used to fit the digitized tumor foci to a paradigm prostate. Pseudo-color summary plots of tumor distribution then were computed for selected cases. RESULTS: Of the 180 specimens, 149 (83%) specimens had more than one cancer focus. Most foci (448 of 607 tumor foci, 74%) were in the peripheral zone (PZ). PZ foci near the apex had a significant midline component. Toward the base, PZ foci diverged laterally. Only 3 (2%) of 180 specimens contained foci solely in the transition zone (TZ). Total TZ cancer volume was

Incidence of adenocarcinoma and mortality in patients with Barrett's oesophagus diagnosed between 1976 and 1986: implications for endoscopic surveillance.

The objective of this study was to investigate the incidence of oesophageal adenocarcinoma and its contribution to mortality in patients with Barrett's oesophagus, and to identify a subgroup of patients who may benefit from endoscopic surveillance. This was a retrospective study of a cohort of 70 patients diagnosed in the endoscopy unit of a Scottish teaching hospital as having Barrett's oesophagus between 1976 and 1986. Information was obtained from case notes, endoscopy records, histology reports and death certificates. Patients were included if they had: (a) columnar-lined oesophagus of at least 3 cm; (b) histological confirmation; and (c) absence of cancer when endoscopically diagnosed as having Barrett's oesophagus. The main outcome for the patients was development of adenocarcinoma or death. Information was available for 59 of 70 patients (84%). Forty-four patients were confirmed to have Barrett's oesophagus and were followed up for 418 patient-years. Only two patients developed oesophageal adenocarcinoma, resulting in an incidence of one case in 209 patient-years, a 55-fold risk compared with age- and sex-matched population in Scotland. Both these patients had intestinal metaplasia and Barrett's ulcer. The majority (90%) of patients died as a result of causes unrelated to adenocarcinoma of oesophagus. In patients under 70 years with intestinal metaplasia, 189 annual endoscopies would have been required to detect one cancer. Adenocarcinoma is an uncommon cause of mortality in patients with Barrett's oesophagus. Endoscopic surveillance is unlikely to alter overall mortality in patients with Barrett's oesophagus. However, by limiting endoscopic surveillance to patients under 70 years with intestinal metaplasia, the estimated cost per cancer detected can be reduced to l23000.

Overexpression of cathepsin B and urokinase plasminogen activator is associated with increased risk of recurrence and metastasis in patients with chondrosarcoma.

BACKGROUND: Deregulation of the cellular protease network has been shown to be responsible for aggressive clinical behavior in several common human malignancies. In the current study, the authors evaluated the expression patterns of proteases in patients with chondrosarcoma of bone and correlated these patterns with clinical outcome. METHODS: The expression levels of urokinase plasminogen activator; matrix metalloproteinase types-1, -2, and -9; and cathepsins B and L were determined immunohistochemically in 114 cases of chondrosarcomas of bone and were correlated with their clinicopathologic parameters as well as with long term follow-up data. RESULTS: Overexpression of cathepsin B was associated with a high rate of local recurrence (P = 0.006) and a decreased recurrence free survival (P = 0.005). Overexpression of urokinase plasminogen activator was associated with an increased rate of metastasis (P = 0. 013), a decreased metastasis free survival (P = 0.016), and a decreased 5-year overall survival rate (P = 0.048). The univariate Cox model showed that tumor extension into soft tissue, high histologic grade, and overexpression of cathepsin B were predictors of adverse outcome. Multivariate analysis showed only overexpression of cathepsin B and tumor extension into soft tissue to be independent predictors of local recurrence. CONCLUSIONS: Overexpression of cathepsin B and urokinase plasminogen activator can be used to identify those patients with chondrosarcoma of bone who have an increased risk of local recurrence and distant metastases.

High tumoral maspin expression is associated with improved survival of patients with oral squamous cell carcinoma.

Maspin, a member of the serpin family of protease inhibitors, is known to have tumor-suppressor functions. However, the association between its expression level and survival has not been demonstrated in human cancer. Using the immunohistochemical technique to examine the expression levels of maspin in 44 cases of oral squamous cell carcinoma (SCC), we found that 66% of the cases expressed low to intermediate levels of maspin and 34% of the cases expressed high levels of maspin. We further examined maspin protein expression in a series of six SCC cell lines from the head and neck, and found that all but one expressed low or no maspin protein. We also compared the clinicopathological features of the oral SCC cases with the maspin expression level, and found that high maspin expression was associated with the absence of lymph node metastasis. More importantly, we showed that higher maspin expression was significantly associated with better rates of overall survival, suggesting that high maspin expression may be a favorable prognostic marker for oral SCC.

Response to open access endoscopy findings by general practitioners guidelines need education for implementation.

General practitioners may gain valuable information from the use of open access endoscopy. The benefit to the individual patient depends on the interpretation of the endoscopy findings and the subsequent action. The aim of the study was to determine GPs response to open access endoscopy findings of three conditions with possible malignant complications: Barrett's oesophagus, gastric ulcer and colonic adenomatous polyps. The study took place at Ninewells Hospital, Dundee. Using the endoscopy unit's records for the year, 1 January 1995 to 31 December 1995, all patients having had an open access upper gastro-intestinal endoscopy or sigmoidoscopy were identified. Case-notes were reviewed of patients who had Barrett's oesophagus, gastric ulcer or colonic polyps diagnosed. During the year, 1158 upper gastro-intestinal endoscopies and 293 sigmoidoscopies were performed by the open access service. The referral rates for the conditions were as follows: Barrett's oesophagus 56%; Gastric ulcers 56%; Adenomatous polyps 88%; Non adenomatous polyps 12.5%. The provision of guidelines does not ensure a high referral rate, education is a vital partner.

Correlation of non-random chromosomal aberrations in lymphocytes of prostate cancer patients with specific clinical parameters.

The purpose of this research was to correlate non-random chromosomal aberrations in the peripheral blood lymphocytes (PBLs) of prostate cancer patients with specific clinical parameters. Peripheral blood samples were analyzed from 59 informative prostate cancer patients. Non-random chromosomal alterations detected in the PBLs and their correlation with any specific clinical parameters were analyzed statistically. A comparison was made between specific chromosomal abnormalities in the patients having an early (<65 years) or late (> or =65 years) age at disease onset, low-grade (Gleason grade <7) or high-grade (Gleason grade > or =7) tumors, a low (<10 ng/ml) or high (> or =10 ng/ml) prostate-specific antigen (PSA) level, and androgen-sensitive or -insensitive disease. In examining the specific chromosomal breakpoints, the regions 1p13, 2q21, 3p21, 4q13, 5q31, 6p21, 7p15, 7p13, 7q32, 10p11, 10q26, 11p15, 11p11, 14q12, and 16q12 showed breaks in at least four cases. Chromosome 15 (P=0. 045) was significantly altered in patients having a PSA value greater than or equal to 10, while it (P=0.017) and chromosome 19 (P=0.036) were significantly altered in patients having a PSA value greater than or equal to 20. In addition, chromosomes 5 (P=0.032), 8 (P=0.020), 16 (P=0.009), and 20 (P=0.047) were significantly altered in patients having a Gleason grade greater than 7. Also, chromosomes 2 (P=0.020) and 3 (P=0.044) were significantly altered in patients who had early disease onset. Additionally, chromosome 10 (P=0.041) was significantly altered in patients having metastasis, and chromosomes 4 (P=0.006) and 7 (P=0.028) were significantly altered in patients having androgen-insensitive disease. In spite of the small subset of patients, chromosome 8 (p=0.003) was significantly altered in patients having small cell carcinoma of the prostate. From these results we conclude that non-random chromosomal aberrations present in PBLs of prostate cancer patients can be correlated with specific clinical parameters. These correlations can be used to identify a prostate cancer patient's risk response to therapy.

Overexpression of a fish CDKN2 gene in a hereditary melanoma model.

The fish genus Xiphophorus provides a vertebrate model useful in etiological studies of cancer. Hybrid fish can spontaneously develop melanomas deriving from the inheritance of melanistic pigment patterns and the simultaneous absence of proper genetic regulation. A cyclin-dependent kinase inhibitor gene, termed CDKN2X, was mapped to a genomic region that is implicated in fish melanoma tumor suppression. The related human tumor suppressor locus CDKN2A (P16, INK4A, MTS1) is deleted, mutated or transcriptionally repressed through methylation of cytosine bases within the 5' CpG island in a variety of neoplasms, including melanoma. The fish CDKN2X locus harbors a CpG island within its promoter and first exon, analogous in location to CpG islands in human CDKN2A and CDKN2B loci. The methylation state of individual CpG dinucleotides was investigated in genomic DNA derived from control tissues and melanomas within the CDKN2X 5' CpG island. The studied genomic area was found to be virtually unmethylated in all tested tissues including melanomas. In addition, RNA expression studies of the fish CDKN2X locus revealed that it is significantly overexpressed in melanoma, in contrast to what has been reported for the human CDKN2A locus in melanoma. Such overexpression may be a consequence of the pronounced upregulation of the Xmrk-2 receptor tyrosine kinase oncogene reported in several Xiphophorus melanoma models.

Genetic modeling of human urinary bladder carcinogenesis.

We developed a model of human urinary bladder cancer progression from in situ precursor lesions to invasive carcinoma using whole organ histologic and genetic mapping. The model represents a high-density and detailed analysis regarding allelic losses on chromosomes 4, 8, 9, 11, and 17 as revealed by testing of 234 samples obtained from five cystectomy specimens. The samples corresponded to microscopically identified intraurothelial precursor conditions ranging from dysplasia to carcinoma in situ and invasive cancer. The initial analysis of paired normal and tumor DNA samples disclosed allelic losses in 72 of 225 tested hypervariable DNA markers. Subsequent use of these markers on all mucosal samples revealed that 47 had alterations with a statistically significant relation to urothelial neoplasia. The allelic losses clustered in 33 distinct chromosomal regions, indicating the location of putative tumor suppressor genes involved in the development and progression of urinary bladder cancer. Some of the markers with statistically significant allelic losses mapped to the regions containing well-characterized tumor suppressor genes but many were located in previously unknown loci. The majority of statistically significant allelic losses (70%) occurred early in low-grade intraurothelial dysplasia, and some of them involved adjacent areas of morphologically normal mucosa preceding the development of microscopically recognizable precursor lesions. The remaining 30% of markers developed allelic losses in the later phases of urothelial neoplasia, implicating their involvement in progression to invasive disease. Markers exhibiting allelic losses in early phases of urothelial neoplasia could be used for detection of occult preclinical or even premicroscopic phases of urinary bladder cancer, whereas markers that showed allelic losses in the later phases of the process could serve as indicators of progression to invasive disease. The approach used in this study facilitates genome-wide modeling of cancer progression and provides important chromosomal landmarks for more specific studies of multistep urinary bladder carcinogenesis.

Performance of a neural network in detecting prostate cancer in the prostate-specific antigen reflex range of 2.5 to 4.0 ng/mL.

OBJECTIVES: To explore the potential role of a neural network-derived algorithm in enhancing the specificity of prostate cancer detection compared with the determination of prostate-specific antigen (PSA) and free PSA (fPSA) while maintaining a 90% detection rate. Recent information suggests that the incidence of detectable prostate cancer is similar in men whose PSA values range from 2.5 to 4.0 ng/mL and from 4.0 to 10.0 ng/mL. If the PSA threshold triggering a prostate biopsy is lowered to 2.5 ng/mL, approximately 13% of men older than 50 would be added to the patient biopsy pool. METHODS: One hundred fifty-one men were enrolled in a prospective, Institutional Review Board-approved protocol to evaluate the incidence of cancer in a population of men who participated in an early-detection program and whose PSA level was between 2.5 and 4.0 ng/mL. All the men underwent biopsy using an 11-core multisite-directed biopsy scheme, and all biopsy specimens were examined by one pathologist. All men had a second blood specimen drawn before the biopsy for a determination of serum PSA, creatinine kinase, prostatic acid phosphatase, and fPSA. A new neural network algorithm was developed with PSA, creatinine kinase, prostatic acid phosphatase, fPSA, and age as input variables to produce a single-valued prostate cancer detection index (PCD-I). This new algorithm was then prospectively tested in the 151 men. Performance parameters (including sensitivity, specificity, positive and negative predictive values, and biopsies saved) were calculated, and a comparative analysis was performed to evaluate the differences among the new algorithm, percent fPSA, PSA density, and PSA density-transition zone. RESULTS: Cancer was histologically confirmed in 24.5% (37 of 151) of the men. The median age of the men was 62 years (range 43 to 74). At a sensitivity of 92%, the specificity for percent fPSA was 11%. The new algorithm (PCD-I) demonstrated an additional enhancement of specificity to 62% at 92% sensitivity. Clinically, the PCD-I would result in a savings of 49% (74 of 151) of all biopsies or 63.6% (71 of 114) of all unnecessary biopsies. CONCLUSIONS: A new generation algorithm, derived from a neural network (PCD-I) incorporating the parameters of age, creatinine kinase, PSA, prostatic acid phosphatase, and fPSA can significantly enhance the specificity and reduce the number of biopsies while maintaining a 92% sensitivity rate.