Marita Laurila

Androgen Receptor Alterations in Prostate Cancer Relapsed during a Combined Androgen Blockade by Orchiectomy and Bicalutamide

Mechanisms of prostate cancer (CaP) recurrence during a combined androgen blockade (CAB) are poorly understood. Previously, the role of androgen receptor (AR) gene mutations underlying the CAB therapy relapse has been raised. To investigate the hypothesis that AR gene aberrations are involved in CAB relapse, 11 locally recurrent CaP samples from patients treated with orchiectomy and bicalutamide were analyzed for copy number changes and DNA sequence alterations of the AR gene by fluorescence in situ hybridization and single-strand conformation polymorphism, respectively. Altogether, base changes were detected in four tumors (36%). Three of them were missense mutations (G166S, W741C, M749I) and two were silent polymorphisms. Interestingly, none of the tumors had AR amplification. These data suggest that different AR variants are developed and selected for during various types of hormonal treatments, and also, that CAB achieved by orchiectomy and bicalutamide does not act as a selective force for AR amplification.

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.

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.

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 κ statistics was applied to determine agreement and significant differences between experts and ERSPC pathologists. The κ 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.

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.

Detection rates of cancer, high grade PIN and atypical lesions suspicious for cancer in the European Randomized Study of Screening for Prostate Cancer

THE AIM OF THE STUDY This article presents the incidence of prostate cancer, isolated high grade prostatic intraepithelial neoplasia (PIN) and atypical lesions suspicious for prostate cancer (LSPC) during subsequent screening rounds in the centres of five of the countries participating in the European Randomized Study of Screening for Prostate Cancer (ERSPC). The incidence and predictive value of high grade PIN and LSPC for prostate cancer in subsequent biopsy following these diagnoses were evaluated. PATIENTS AND METHODS Study group consisted of 56,653 screened men in the ERSPC centres of Finland, Italy, Netherlands, Sweden and Switzerland, who underwent 3-7 screening rounds at 2-4 year interval. Data for prostate cancer were obtained from the ERSPC central database. Data for high grade PIN and LSPC were gathered from each ERSPC centre. Detection rates of subsequent prostate cancer in the first re-biopsy after these diagnoses were determined. RESULTS The average cancer detection rate was 3.5%, 3.2% and 3.5% for the completed rounds 1, 2 and 3, respectively, in all five centres. Incidence of high grade PIN increased from 1.5% in the first round to 5.0% in the third round, varying among centres in the first round between 0.8% and 7.6%. The cancer detection rate in the first re-biopsy after the diagnosis of high grade PIN was 12.9%. Incidence of LSPC was 2.4%, 2.7%, 2.2% and 2.6% in the first, second, third and fourth round, respectively. The cancer detection rate at the first re-biopsy after the diagnosis of LSPC was in average 33.8%. CONCLUSIONS Cancer detection rate was stable during the three screening rounds. The wide variation in frequency in particular of high grade PIN among the ERSPC centres suggests a considerable inter-observer variation. The average comparatively low detection rate of isolated high grade PIN in the first screening round may be screening-related, while its consistent increase during three screening rounds could be the consequence of a.o. previous screening and ageing of the population. The observed low risk of prostate cancer after isolated high grade PIN in this screening setting is in line with the current recommendation to abstain from early repeat biopsies after this diagnosis. The association of LSPC with high incidence of prostate cancer in re-biopsies confirms the need for early repeat biopsies and follow-up of these men. The low percentage of LSPC (<3% of biopsies) throughout all rounds is reassuring as it limits the biopsy burden in a screening setting.

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

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.

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.

Chromosomal changes in locally recurrent, hormone-refractory prostate carcinomas by karyotyping and comparative genomic hybridization

The genetic mechanisms of prostate cancer recurrence during hormonal therapy are largely unknown. So far, data from conventional karyotype analysis on hormone-refractory prostate carcinomas have not been published, mainly because of the difficulties in obtaining fresh hormone-refractory prostate carcinoma samples and getting metaphases from them. Here, we have studied chromosomal changes in 12 locally recurrent, hormone-refractory prostate carcinomas using karyotyping and CGH that revealed genetic aberrations in all tumors. Loss of the Y chromosome was the most common (89%) finding, and tetraploidy or near-tetraploidy was detected in all tumors. Also non-random translocations were found in 56% of the tumors. The present study indicates that clonal chromosomal aberrations in hormone-refractory prostate carcinomas are more common than in untreated primary tumors, and also, further studies on the frequency and significance of translocations in prostate carcinoma progression during hormonal therapy are warranted.

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.

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.