Expected impact of MRI-targeted biopsy interreader variability among uropathologists on ProScreen prostate cancer screening trial: a pre-trial validation study.

PURPOSE: Prostate cancer (PCa) histology, particularly the Gleason score, is an independent prognostic predictor in PCa. Little is known about the inter-reader variability in grading of targeted prostate biopsy based on magnetic resonance imaging (MRI). The aim of this study was to assess inter-reader variability in Gleason grading of MRI-targeted biopsy among uropathologists and its potential impact on a population-based randomized PCa screening trial (ProScreen). METHODS: From June 2014 to May 2018, 100 men with clinically suspected PCa were retrospectively selected. All men underwent prostate MRI and 86 underwent targeted prostate of the prostate. Six pathologists individually reviewed the pathology slides of the prostate biopsies. The five-tier ISUP (The International Society of Urological Pathology) grade grouping (GG) system was used. Fleiss' weighted kappa (κ) and Model-based kappa for associations were computed to estimate the combined agreement between individual pathologists. RESULTS: GG reporting of targeted prostate was highly consistent among the trial pathologists. Inter-reader agreement for cancer (GG1-5) vs. benign was excellent (Model-based kappa 0.90, Fleiss' kappa κ = 0.90) and for clinically significant prostate cancer (csPCa) (GG2-5 vs. GG0 vs. GG1), it was good (Model-based kappa 0.70, Fleiss' kappa κ 0.67). CONCLUSIONS: Inter-reader agreement in grading of MRI-targeted biopsy was good to excellent, while it was fair to moderate for MRI in the same cohort, as previously shown. Importantly, there was wide consensus by pathologists in assigning the contemporary GG on MRI-targeted biopsy suggesting high reproducibility of pathology reporting in the ProScreen trial.

Robotic-assisted vs traditional laparoscopic surgery for endometrial cancer: a randomized controlled trial.

BACKGROUND: Previous studies comparing robotic-assisted laparoscopic surgery to traditional laparoscopic or open surgery in gynecologic oncology have been retrospective. To our knowledge, no prospective randomized trials have thus far been performed on endometrial cancer. OBJECTIVE: We sought to prospectively compare traditional and robotic-assisted laparoscopic surgery for endometrial cancer. STUDY DESIGN: This was a randomized controlled trial. From December 2010 through October 2013, 101 endometrial cancer patients were randomized to hysterectomy, bilateral salpingo-oophorectomy, and pelvic lymphadenectomy either by robotic-assisted laparoscopic surgery or by traditional laparoscopy. The primary outcome measure was overall operation time. The secondary outcome measures included total time spent in the operating room, and surgical outcome (number of lymph nodes harvested, complications, and recovery). The study was powered to show at least a 25% difference in the operation time using 2-sided significance level of .05. The differences between the traditional laparoscopy and the robotic surgery groups were tested by Pearson χ2 test, Fisher exact test, or Mann-Whitney test. RESULTS: In all, 99 patients were eligible for analysis. The median operation time in the traditional laparoscopy group (n = 49) was 170 (range 126-259) minutes and in the robotic surgery group (n = 50) was 139 (range 86-197) minutes, respectively (P < .001). The total time spent in the operating room was shorter in the robotic surgery group (228 vs 197 minutes, P < .001). In the traditional laparoscopy group, there were 5 conversions to laparotomy vs none in the robotic surgery group (P = .027). There were no differences as to the number of lymph nodes removed, bleeding, or the length of postoperative hospital stay. Four (8%) vs no (0%) patients (P = .056) had intraoperative complications and 5 (10%) vs 11 (22%) (P = .111) had major postoperative complications in the traditional and robotic surgery groups, respectively. CONCLUSION: In patients with endometrial cancer, robotic-assisted laparoscopic surgery was faster to perform than traditional laparoscopy. Also total time spent in the operation room was shorter in the robotic surgery group and all conversions to laparotomy occurred in the traditional laparoscopy group. Otherwise, the surgical outcome was similar between the groups. Robotic surgery offers an effective and safe alternative in the surgical treatment of endometrial cancer.

Muraglitazar-eluting bioabsorbable vascular stent inhibits neointimal hyperplasia in porcine iliac arteries.

PURPOSE: To evaluate the biocompatibility of a new muraglitazar-eluting polylactide copolymer stent and investigate its ability to prevent the formation of intimal hyperplasia. MATERIALS AND METHODS: Ten self-expandable muraglitazar-eluting poly-96 L/4D-lactic acid (PLA96) stents and 10 self-expandable control PLA96 stents were implanted into porcine common iliac arteries. After 28 days follow-up, all stent-implanted iliac arteries were harvested and prepared for quantitative histomorphometric analysis. RESULTS: Angiographic analysis revealed that one control PLA96 stent had occluded and one had migrated. Histomorphometric analysis demonstrated that, with the control PLA96 stent, the luminal diameter and area were decreased versus the muraglitazar-eluting PLA96 stents (means ± standard error of the mean, 3.58 mm ± 0.34 vs 4.16 mm ± 0.14 and 9.83 mm(2) ± 2.41 vs 13.75 mm(2) ± 0.93, respectively). The control PLA96 stent induced more intimal hyperplasia than the bioactive muraglitazar-eluting PLA96 stent (557 µm ± 122 vs 361 µm ± 32). Vascular injury scores demonstrated only mild vascular trauma for both stents (muraglitazar-eluting, 0.68 ± 0.07; control, 0.75 ± 0.08). Inflammation scores also showed mild inflammation for both stents (muraglitazar-eluting, 1.05 ± 0.17; control, 1.23 ± 0.19). CONCLUSIONS: This new muraglitazar-eluting PLA96 stent was shown to be biocompatible with a tendency for better patency and less intimal hyperplasia compared with the control PLA96 stents.

Length of prostate biopsies is not necessarily compromised by pooling multiple cores in one paraffin block: an observational study.

BACKGROUND: Individually submitted prostatic needle biopsies are recommended by most guidelines because of their potential advantage in terms of core quality. However, unspecified bilateral biopsies are commonly submitted in many centers. The length of the core is the key quality indicator of prostate biopsies. Because there are few recent publications comparing the quality of 12 site-designated biopsies versus pooled biopsies, we compared the lengths of the biopsies obtained by both methods. METHODS: The material was obtained from 471 consecutive subjects who underwent prostatic needle biopsy in the Tampere University Hospital district between January and June 2013. Biopsies from 344 subjects fulfilled the inclusion criteria. The total number of cores obtained was 4047. The core lengths were measured on microscope slides. Extraprostatic tissue was subtracted from the core length. RESULTS: The aggregate lengths observed were 129.5 ± 21.8 mm (mean ± SD) for site-designated cores and 136.9 ± 26.4 mm for pooled cores (p = 0.09). The length of the core was 10.8 ± 1.8 mm for site-designated cores and 11.4 ± 2.2 mm for pooled cores (p = 0.87). The median length for pooled cores was 11 mm (range 5 mm - 18 mm). For individual site-designated cores, the median length was 11 mm (range 7 mm -15 mm). The core length was not correlated with the number of cores embedded into one paraffin block (r = 0.015). There was no significant difference in cancer detection rate (p = 0.62). CONCLUSIONS: Our results suggest that unspecified bilateral biopsies do not automatically lead to reduced core length. We conclude that carefully embedded multiple (three to nine) cores per block may yield cores of equal quality in a more cost-efficient way and that current guidelines favoring individually submitted cores may be too strict.

Histological inflammation and risk of subsequent prostate cancer among men with initially elevated serum prostate-specific antigen (PSA) concentration in the Finnish prostate cancer screening trial.

OBJECTIVE: To assess whether histological signs of inflammation are associated with an increased risk of subsequent prostate cancer (PCa) in men with elevated serum prostate-specific antigen (PSA) concentrations and benign initial biopsy. MATERIALS AND METHODS: Study subjects were men aged 54-67 years with an elevated PSA (≥4 ng/mL or 3-4 ng/mL and free to total PSA ratio ≤0.16 or positive digital rectal examination), but a benign biopsy result within the Finnish population-based randomised screening trial for PCa, which started in 1996. A total of 293 prostate biopsies without PCa or suspicion of malignancy from the first screening round in the Tampere centre were re-evaluated by a uropathologist to assess histological inflammation. Results of the subsequent screening rounds were obtained from the trial database and PCa diagnoses made outside the screening were obtained from the Finnish Cancer Registry. The median length of follow-up was 10.5 years. Cox regression analysis was used to assess PCa risk after the initial benign biopsy. RESULTS: Histological inflammation was found in 66% of the biopsies. Subjects with inflammation at the biopsy had a slightly lower PCa risk in the second screening round (18 vs 27%, rate ratio 0.69, 95% confidence interval [CI] 0.35-1.34) relative to men without inflammation. In further follow-up, the PCa risk remained nonsignificantly lower (hazard ratio [HR] 0.71, CI 0.46-1.10; P = 0.13). The risk was not appreciably affected by adjustment for age, PSA, prostate volume and family history of PCa (HR 0.67, CI 0.42-1.07; P = 0.092). CONCLUSIONS: Histological inflammation in a prostate biopsy among men with an initial false-positive screening test was not associated with an increased risk of subsequent PCa, but instead with a decreased risk which was of borderline significance. Inflammation in prostate biopsy is not a useful risk indicator in PCa screening.

Atypical urothelial cells classified according to the Paris System for Reporting Urinary Cytology: A 2-year experience with histological correlation from a Finnish tertiary care center-low rate and high risk of malignancy.

BACKGROUND: The Paris System for Reporting Urinary Cytology (TPS) was issued to shift the focus of urine cytology to high-grade lesions to increase the diagnostic accuracy of urine cytology. The aim of this study was to evaluate the power of TPS in the atypical urothelial cells (AUC) category with histological correlation and follow-up. METHODS: The data cohort consisted of 3741 voided urine samples collected during a 2-year period between January 2017 and December 2018. All samples were prospectively classified using TPS. This study focuses on the subset of 205 samples (5.5%) classified as AUC. All cytological and histological follow-up data were analyzed until 2019, and the time between each sampling was documented. RESULTS: Of the 205 AUC cases, cytohistological correlation was possible in 97 (47.3%) cases. Of these, 36 (12.7%) were benign in histology, 27 (13.2%) were low-grade urothelial carcinomas, and 34 (16.6%) were high-grade urothelial carcinomas. Overall, the risk of malignancy was 29.8% for all cases in the AUC category, and 62.9% in the histologically confirmed cases. The risk of high-grade malignancy was 16.6% in all the AUC category samples and 35.1% in the histological follow-up group. CONCLUSIONS: The performance of 5.5% AUC cases is considered good and within the limits proposed by TPS. TPS is widely accepted by cytotechnologists, cytopathologists, and clinicians; it improves communication and patient management.

The preoperative assessment of deep myometrial invasion by three-dimensional ultrasound versus MRI in endometrial carcinoma.

OBJECTIVE: To evaluate the usefulness of three-dimensional ultrasound (3D US), magnetic resonance imaging (MRI) and three-dimensional power Doppler angiography (3D-PDA) in the preoperative assessment of myometrial invasion in endometrial carcinoma. DESIGN: A prospective observational study. SETTING: University hospital. POPULATION: Twenty consecutive patients diagnosed with endometrial carcinoma. METHODS: Preoperative 3 T MRI and 3D US examinations were performed, and the depth of myometrial invasion was assessed. The vascularity indices, vascularization index, flow index and vascularization flow index, were calculated by 3D-PDA. MAIN OUTCOME MEASURES: The results were compared with the final histopathology report after a surgical staging. RESULTS: In detecting deep myometrial invasion, the sensitivity of 3D US, MRI and their combination was 50, 91.7 and 100%, respectively. The specificity was 87.5, 50 and 50%, respectively. There were no significant differences in the 3D-PDA vascularity indices between the two groups. CONCLUSIONS: MRI appears to be more sensitive than 3D US in detecting deep invasion, while 3D US has a better specificity.

Endocervical Cytology: Inter- and Intra-Observer Variability in Conventional Pap Smears.

INTRODUCTION: Although the cytological diagnostic criteria for cervical squamous and glandular lesions are established by the Bethesda System for Reporting Cervical Cytology, the reproducibility of the diagnosis of these lesions has been shown to be variable in previous studies. At best, occasional good kappa (κ) values were reached both inter- and intra-observerly. Generally, consensus on high-grade lesions has been better compared to milder changes. METHODS: Altogether, 167 conventional Pap smears from 50 patients with histologically confirmed endocervical adenocarcinomas (EAC) and adenocarcinomas in situ (AIS) and from 28 patients with histologically proven high-grade intraepithelial lesions were analyzed by four cytopathologists. Twenty of the smears were later re-evaluated by the same cytopathologists. κ-values between cytopathologists in the categories of squamous versus glandular, negative for intraepithelial lesion or malignancy (NILM), atypical, and preneoplastic/neoplastic were calculated. The diagnostic Pap smears of EAC and AIS with best and worst consensus between observers were then morphologically analyzed. RESULTS: The reproducibility ranged from poor to substantial. The overall κ-values between the four cytopathologists were 0.412, 0.314, 0.272, and 0.082, respectively, in the categories of preneoplastic/neoplastic, squamous versus glandular, NILM, and atypical. Overall intra-observer κ-values were correspondingly 0.491, 0.616, 0.345, and 0.241. In the diagnostic smears of AIS and EAC, the nuclear size >2 times the normal and nuclear pleomorphism were the commonest features associated with good diagnostic consensus and the lack of nuclear enlargement and degenerative changes were associated with poor consensus. CONCLUSIONS: The reproducibility of preneoplasia/neoplasia diagnoses was better than that of atypia and NILM both in the inter- and intra-observer part in this study. In the smears from AIS and EAC patients, general neoplasia-associated features were more common in samples with good agreement by the four cytopathologists of the neoplastic nature and the endocervical origin of the lesion.

Paclitaxel, Carboplatin and 1,25-D3 Inhibit Proliferation of Ovarian Cancer Cells In Vitro.

BACKGROUND/AIM: The combination of paclitaxel and carboplatin is the standard chemotherapy for ovarian cancer. Previous studies have implied that vitamin D (1,25-D3) may have growth inhibitory effects in ovarian cancer. This study aimed to investigate the effect of paclitaxel, carboplatin and 1,25-D3 on the growth of ovarian cancer cells in vitro, based on the hypothesis that 1,25-D3 might potentiate the effect of paclitaxel and/or carboplatin. MATERIALS AND METHODS: Three non-commercial ovarian carcinoma cell lines UT-OV-1(mucinous), UT-OV-3B (serous) and UT-OV-4 (endometrioid) were exposed to different concentrations of 1,25-D3, paclitaxel and carboplatin, respectively. The cell viability was measured using a Crystal violet assay kit. The cellular vitamin D receptor (VDR) mRNA levels were measured by qRT-PCR using the LightCycler equipment. RESULTS: The growth-inhibitory effect of the combination of paclitaxel and carboplatin was 56% in UT-OV-1, 33% in UT-OV-3B and 47% in UT-OV-4 cells. Single 1,25-D3 (10 µM) inhibited the growth of UT-OV-3B and UT-OV-4 by 23% and 28%, respectively, whereas no effect was seen in UT-OV-1 cells. These results are in line with the finding that the expression of VDR was high in UT-OV-3B and UT-OV-4, but very low in UT-OV-1. The combination of 1,25-D3, paclitaxel and carboplatin resulted in 61%, 46% and 58% growth reduction in UT-OV-1, UT-OV-3B and UT-OV-4 cells, respectively. The additive effect of 1,25-D3 was 21% in UT-OV-4, 20% in UT-OV-3B and 12% in UT-OV-1 cell line. CONCLUSION: The results imply that combining 1,25-D3 with paclitaxel and carboplatin may potentiate their growth inhibitory effect on ovarian cancer cells with high VDR expression.

Biological aggressiveness of prostate cancer in the Finnish screening trial.

Prostate cancer aggressiveness was evaluated based on pathologic characterization of cases detected in the Finnish prostate cancer screening trial. The trial population consists of 80,458 men aged 55-67 years. A total of 32,000 men were randomized to the screening arm. The remaining 48,000 men formed the control arm. The interval cases and cancers among nonparticipants and in the control arm were identified from the Finnish Cancer Registry. Random samples were selected from screen-detected cases (126 of 543 in the first and 133 of 508 in the second round) and control arm cancers (133 out of 863), in addition to all 92 interval cancers and 106 cases among nonparticipants. All the biopsies were regraded according to the Gleason system. The expression of the proliferation antigen Ki-67 was determined in 479 cases (72%). More than half of the tumors diagnosed in the first round of screening were high-grade cancers (Gleason 7 or higher). In the second round, the proportion of low-grade cancers increased from 47% to 70%. Cancers in the screening arm were more commonly focal and fewer bilateral cancers were detected. The cancers among nonparticipants were the most aggressive group. The aggressiveness of the interval cancers was between the cancers detected in the first and the second round. Our results indicate that prostate cancers detected through screening are less biologically aggressive. This was most notable after the first screening round. Nonparticipants had more aggressive cancers.

Feasibility of Prostate PAXgene Fixation for Molecular Research and Diagnostic Surgical Pathology: Comparison of Matched Fresh Frozen, FFPE, and PFPE Tissues.

Advances in prostate cancer biology and diagnostics are dependent upon high-fidelity integration of clinical, histomorphologic, and molecular phenotypic findings. In this study, we compared fresh frozen, formalin-fixed paraffin-embedded (FFPE), and PAXgene-fixed paraffin-embedded (PFPE) tissue preparation methods in radical prostatectomy prostate tissue from 36 patients and performed a preliminary test of feasibility of using PFPE tissue in routine prostate surgical pathology diagnostic assessment. In addition to comparing histology, immunohistochemistry, and general measures of DNA and RNA integrity in each fixation method, we performed functional tests of DNA and RNA quality, including targeted Miseq RNA and DNA sequencing, and implemented methods to relate DNA and RNA yield and quality to quantified DNA and RNA picogram nuclear content in each tissue volume studied. Our results suggest that it is feasible to use PFPE tissue for routine robot-assisted laparoscopic prostatectomy surgical pathology diagnostics and immunohistochemistry, with the benefit of significantly improvedDNA and RNA quality and RNA picogram yield per nucleus as compared with FFPE tissue. For fresh frozen, FFPE, and PFPE tissues, respectively, the average Genomic Quality Numbers were 7.9, 3.2, and 6.2, average RNA Quality Numbers were 8.7, 2.6, and 6.3, average DNA picogram yields per nucleus were 0.41, 0.69, and 0.78, and average RNA picogram yields per nucleus were 1.40, 0.94, and 2.24. These findings suggest that where DNA and/or RNA analysis of tissue is required, and when tissue size is small, PFPE may provide important advantages over FFPE. The results also suggest several interesting nuances including potential avenues to improve RNA quality in FFPE tissues and confirm recent suggestions that some DNA sequence artifacts associated with FFPE can be avoided.

Paclitaxel, Carboplatin and 1,25-D3 Inhibit Proliferation of Endometrial Cancer Cells In Vitro.

BACKGROUND/AIM: Endometrial cancer cells are known to be sensitive to carboplatin and paclitaxel. Furthermore, vitamin D (1,25-D3) has been reported to inhibit endometrial cancer cell growth both as a single agent and combined with carboplatin. However, there are no studies comparing the effect of paclitaxel and carboplatin as single agents vs. in combination in endometrial cancer cell lines. Neither has the effect of 1,25-D3 been studied with paclitaxel. The present study investigated the effect of paclitaxel, carboplatin and 1,25-D3 on the growth of endometrial cancer cells in vitro. MATERIALS AND METHODS: Two endometrial adenocarcinoma cell lines (UT-EC-1 and UT-EC-3) were cultured with different doses of paclitaxel, carboplatin and 1,25-D3. The cellular VDR (vitamin D receptor) mRNA levels were measured and the expression of estrogen (ER) and progesterone (PR) receptors by the cells was determined. RESULTS: In the UT-EC-1 cell line the growth inhibition was 72% with paclitaxel, 54% with carboplatin and 73% with the combination of these compounds. The corresponding numbers in UT-EC-3 were 70%, 33% and 65%, respectively. 1,25-D3 suppressed cell growth 88% with paclitaxel, 63% with carboplatin and 87% with their combination in the UT-EC-1 cell line. CONCLUSION: In both cell lines, single-agent paclitaxel was as effective as the combination of the compounds and more effective than single carboplatin. 1,25-D3 may further contribute to the cytotoxic effect of these agents.

Routine dual-color immunostaining with a 3-antibody cocktail improves the detection of small cancers in prostate needle biopsies.

We performed dual-color immunostaining with a 3-antibody cocktail (α-methylacyl coenzyme-A racemase, CK34betaE12, and p63) on prostate biopsies from 200 patients. Current practice (hematoxylin and eosin staining followed by dual-color immunostaining on selected cases) was compared with a protocol in which routine dual-color immunostaining was provided in all cases. In the original pathology reports, adenocarcinoma was diagnosed in 87/200 (43%) patients. Small foci interpreted as putative cancers were detected with dual-color immunostaining in 14/113 patients who were originally diagnosed with a nonmalignant lesion. All of the suggested cancerous foci were independently reevaluated by 5 pathologists. A diagnosis of adenocarcinoma was assessed by consensus in 8 cases, and atypical small acinar proliferation was diagnosed in 1 case. Consensus was not reached in 5 cases. Six of the foci reclassified as cancer were of Gleason score 3 + 3 = 6, while 2 were graded as Gleason score 4 + 4 = 8. The feasibility of routine dual-color immunostaining was also tested by analyzing the time spent on microscopic assessment. Because small, atypical lesions expressing α-methylacyl coenzyme-A racemase (blue chromogen) were easy to detect using dual-color immunostaining, the microscopic analysis of dual-color immunostaining and hematoxylin-eosin staining was faster than that of hematoxylin-eosin staining alone that was later followed by dual-color immunostaining in selected cases (median 251 seconds versus 299 seconds, P < .0001). We concluded that routine dual-color immunostaining of all prostate biopsies would produce better diagnostic sensitivity with a smaller microscopy workload for the pathologist. However, minute foci interpreted as cancer with dual-color immunostaining need to be confirmed with hematoxylin-eosin staining, and minimal criteria for a definitive diagnosis of cancer are still lacking.

Variability in diagnostic opinion among pathologists for single small atypical foci in prostate biopsies.

Pathologists are increasingly exposed to prostate biopsies with small atypical foci, requiring differentiation between adenocarcinoma, atypical small acinar proliferation suspicious for malignancy, and a benign diagnosis. We studied the level of agreement for such atypical foci among experts in urologic pathology and all-round reference pathologists of the European Randomized Screening study of Prostate Cancer (ERSPC). For this purpose, we retrieved 20 prostate biopsies with small (most <1 mm) atypical foci. Hematoxylin and eosin-stained slides, including 10 immunostained slides were digitalized for virtual microscopy. The lesional area was not marked. Five experts and 7 ERSPC pathologists examined the cases. Multirater kappa statistics was applied to determine agreement and significant differences between experts and ERSPC pathologists. The kappa value of experts (0.39; confidence interval, 0.29-0.49) was significantly higher than that of ERSPC pathologists (0.21; confidence interval, 0.14-0.27). Full (100%) agreement was reached by the 5 experts for 7 of 20 biopsies. Experts and ERSPC pathologists rendered diagnoses ranging from benign to adenocarcinoma on the same biopsy in 5 and 9 biopsies, respectively. Most of these lesions comprised between 2 and 5 atypical glands. The experts diagnosed adenocarcinoma (49%) more often than the ERSPC pathologists (32%) (P<0.001). As agreement was particularly poor for foci comprising <6 glands, we would encourage pathologists to obtain intercollegial consultation of a specialized pathologist for these lesions before a carcinoma diagnosis, whereas clinicians may consider to perform staging biopsies before engaging on deferred or definite therapy.

Biocompatibility properties of a new braided biodegradable urethral stent: a comparison with a biodegradable spiral and a braided metallic stent in the rabbit urethra.

OBJECTIVE: To compare the biocompatibility properties of a new braided biodegradable self-reinforced poly-L-lactic acid (SR-PLLA) urethral stent to the former spiral biodegradable SR-PLLA stent and the stainless steel stent in a rabbit model. MATERIALS AND METHODS: In all, 54 male New Zealand White rabbits were anaesthetized and stents inserted into the prostatic urethra, three of each kind for each sample time. The rabbits were killed after 1, 3, 6, 9, 12 or 15 months and light microscopy and scanning electron microscopy used to analyse the effects. RESULTS: The disintegration of the braided SR-PLLA stent was more closely controlled than that of the spiral SR-PLLA stent. The metallic stent induced epithelial hyperplasia and polyposis earlier than the biodegradable stents, and in these rabbits the polyposis disappeared after the disintegration process. There were no differences in the histological analyses between the biodegradable stents, whereas the metallic stents caused the strongest inflammatory reactions. CONCLUSIONS: The braided SR-PLLA urethral stent functioned well in the rabbit urethra and clinical studies are already planned.

Detection rates of high-grade prostate cancer during subsequent screening visits. Results of the European Randomized Screening Study for Prostate Cancer.

Screening for prostate cancer using prostate-specific antigen (PSA) tests has led to a stage and grade shift as compared to the pre-PSA era. Effectiveness of screening for prostate cancer should be manifested by a reduction in detection rate of aggressive cancers during subsequent screening. In 6 centers of the European Randomized Screening study for Prostate Cancer, a total of 58,710 men were tested for prostate cancer. Screening centers differed with regard to age-range, screening interval and biopsy indications. During the 2nd visit, the proportion of Gleason score 6 cancers increased from 62.5 to 75%, mainly at the expense of Gleason score 7 cancers. High-grade (Gleason score 8-10) cancer detection rates varied per screening center during the 1st visit from 5.1 to 41.1, and during the 2nd visit from 6.4 to 29.3/10,000 men. The overall detection rate of high-grade cancers showed a reduction during the 2nd visit from 26 to 12/10,000 men, an effect mainly attributable to the screening center with the highest cancer detection rate (i.e. 507/10,000 men). Variations in detection rates among screening centers related among others to biopsy compliance and age range.

Biocompatibility and implantation properties of 2 differently braided, biodegradable, self-reinforced polylactic acid urethral stents: an experimental study in the rabbit.

PURPOSE: Biodegradable urethral stents have been in clinical use for more than 10 years. To solve the problems connected with the helical spiral configuration of the stents used to date we developed a new tubular mesh configuration and evaluated the biocompatibility properties and degradation time of 2 differently braided stents in the rabbit urethra. MATERIALS AND METHODS: The biodegradable, self-expanding stents were made of self-reinforced polylactic acid polymer blended with BaSO4 (Alfa Chem, Kings Point, New York). Two braiding patterns, namely a diamond 1/1 and a regular 2/2 + 1 (Prodesco, Perkasie, Pennsylvania), were used to produce a tubular mesh configuration. Stainless steel stents with 1/1 braiding served as controls. The stents were inserted into the posterior urethra of 36 male rabbits. The animals were sacrificed after 1 week, 1 month, 6 months or 12 months. Light microscopy and scanning electron microscopy analyses were done. RESULTS: Tissue reactions to operative trauma were seen in all specimens at week 1. The changes gradually abated in the biodegradable stent groups, whereas chronic inflammatory changes and fibrosis were increasingly seen with metallic stents after 6 months. Epithelial hyperplasia increased with time for all stent types and materials. As expected, stent fragmentation started at 6 months. CONCLUSIONS: Biodegradable polymers are suitable materials for braided urethral stents. However, the braided configuration of the stent with a decreased mass of material does not prevent the development of epithelial hyperplasia. The biodegradable, self-expanding, braided stents functioned well in the rabbit urethra and are suitable for clinical studies.

Biocompatibility, encrustation and biodegradation of ofloxacine and silver nitrate coated poly-L-lactic acid stents in rabbit urethra.

The purpose of this study was to evaluate the biocompatibility, encrustation and biodegradation properties of silver nitrate and ofloxacine blended caprolactone-L-lactide copolymer coated self-reinforced poly-L-lactic acid (SR-PLLA) urospirals in situ in the male rabbit urethra. SR-PLLA urospirals coated with 10% by weight silver nitrate or 5% by weight ofloxacine blended copolymer or pure copolymer were inserted into the posterior urethra of 18 male rabbits. No prophylactic antibiotics were given. The animals were sacrificed 1 or 6 months after insertion. Urethral tissue reactions were histologically scored semiquantitavely and the appearence of the stents assessed using scanning electron microscopy. The biodegradation time of SR-PLLA stents was remarkably reduced by the caprolactone coating. Silver nitrate and ofloxacine blended copolymer coated urospirals caused less tissue reaction than urospirals with a pure copolymer coating. Silver nitrate coating effectively prevented biofilm formation and stent encrustation. Silver nitrate and ofloxacine blended copolymer coated SR-PLLA urospirals had good biocompatibility properties in rabbit urethra. In particular, coating with silver nitrate may provide possibilities of preventing bacterial adhesion to bioabsorbable stents.

Rabbit muscle and urethral in situ biocompatibility properties of the self-reinforced L-lactide-glycolic acid copolymer 80: 20 spiral stent.

PURPOSE: A new type of self-reinforced L-lactide-glycolic acid copolymer, molar ratio 80:20, stent was developed. We evaluated the tissue biocompatibility properties of the new material. MATERIALS AND METHODS: Rods made of self-reinforced L-lactide-glycolic acid copolymer were inserted into rabbit dorsal muscles and rods of latex or polyvinylchloride and silicone served as positive and negative controls, respectively. Urethral stents of self-reinforced L-lactide-glycolic acid copolymer and steel were inserted in situ via cystoscopy into the rabbit prostatic urethra. The animals were sacrificed after 2 weeks, 1, 2 and 3 months, respectively. In situ histological analysis was done. Tissue reactions around the implantation types were analyzed histologically and scored semiquantitatively. In addition, macroscopic analysis was done of the urethral in situ stents. RESULTS: In rabbit muscle implantation test tissue reaction to the self-reinforced L-lactide-glycolic acid copolymer stent resembled that of negative control silicone. Less than moderate chronic inflammatory changes gradually subsided after 2 weeks. Foreign materials in the tissue and the reaction to these materials began to disappear after 1 month and at 3 months were completely absent. All rabbits fitted with the stent voided normally postoperatively. Self-reinforced L-lactide-glycolic acid copolymer stents were soft, partially fragmented and easily disintegrated when touched at 2 months, and were almost completely degraded at 3 months. The material did not encroach into the urethral wall macroscopically or microscopically. No calcification on the self-reinforced L-lactide-glycolic acid copolymer stents or bladder stone formation was seen. CONCLUSIONS: The new self-reinforced L-lactide-glycolic acid copolymer 80:20 material is safe, highly biocompatible and suited for future clinical use. It is most appropriate for preventing postoperative urinary retention after most minimally invasive thermal treatments for benign prostatic hyperplasia.