A. Jedrzejczyk

EORTC risk tables - their usefulness in the assessment of recurrence and progression risk in non-muscle-invasive bladder cancer in Polish patients.

Introduction The assessment of risk of recurrence and progression of bladder cancer (BC) is still rather difficult. We decided to check the rates of the changes mentioned above in the group of the Polish patients after a year–long observation and next to compare them with the results calculated in the European Organisation of Research and Treatment of Cancer (EORTC) risk tables. Methods The tested group consisted of 91 patients who underwent transurethral resection of bladder tumour (TURBT). When being diagnosed, 60 cases were in the pTa clinical stage, whereas 30 cases were in T1. The coexisting carcinoma in situ (CIS) was observed in four cases. On the basis of the scores obtained from the EORTC tables, the patients were divided into the groups of low, intermediate or high risk of disease recurrence and progression. Results Recurrence was noticed in 23 patients (25%), while progression was observed in 11 patients (12.1%). The rate of the observed recurrences proved to be lower than it had been predicted in all the groups, except for one of the intermediate–risk group (score 1– 4). Moreover, the rate of the progressions predicted according to the EORTC risk tables was higher in all the risk groups. Conclusions It can be noticed that the rate of real recurrences is lower than expected, whereas the rate of the observed progressions is overestimated. Partly, it could be the result of using a relatively small group of patients for observation and applying a different method of treatment.

Molecular subtyping of bladder cancer using Kohonen self-organizing maps.

Kohonen self‐organizing maps (SOMs) are unsupervised Artificial Neural Networks (ANNs) that are good for low‐density data visualization. They easily deal with complex and nonlinear relationships between variables. We evaluated molecular events that characterize high‐ and low‐grade BC pathways in the tumors from 104 patients. We compared the ability of statistical clustering with a SOM to stratify tumors according to the risk of progression to more advanced disease. In univariable analysis, tumor stage (log rank P = 0.006) and grade (P < 0.001), HPV DNA (P < 0.004), Chromosome 9 loss (P = 0.04) and the A148T polymorphism (rs 3731249) in CDKN2A (P = 0.02) were associated with progression. Multivariable analysis of these parameters identified that tumor grade (Cox regression, P = 0.001, OR.2.9 (95% CI 1.6–5.2)) and the presence of HPV DNA (P = 0.017, OR 3.8 (95% CI 1.3–11.4)) were the only independent predictors of progression. Unsupervised hierarchical clustering grouped the tumors into discreet branches but did not stratify according to progression free survival (log rank P = 0.39). These genetic variables were presented to SOM input neurons. SOMs are suitable for complex data integration, allow easy visualization of outcomes, and may stratify BC progression more robustly than hierarchical clustering.

polymorphic variants of H-raS protooncogene and their possible role in bladder cancer etiology

Introduction H-RAS gene is a protooncogene encoding p21ras, a small protein with GTPase activity. This protein is a component of many signaling cascades, while mutations in H-RAS gene are often found in urinary bladder cancer and leads to continuous transmission of signals stimulating cancer cell growth and proliferation. The T81C polymorphism of H-RAS gene is a SNP, which, although does not seem to impair p21ras protein structure and function, may contribute to the development of bladder cancer. Objectives The aim of our study was to characterize the prevalence and clinical significance of T81C polymorphism in patients with diagnosed bladder cancer. Materials and methods 132 patients with diagnosed urinary bladder cancer were included in this study. The control group consisted of 106 healthy individuals. The experimental material was DNA, isolated from tumor tissue and peripheral blood lymphocytes. T81C polymorphism was detected using the MSSCP method and DNA sequencing. Results In the examined DNA samples, frequent polymorphic variations were found in codon 27 of H-RAS gene. In order to assess the clinical relevance of the polymorphism, the results were compared with those for the control group. The homozygous CC variant occurred more frequently in bladder cancer patients than in healthy individuals. Conclusions DNA polymorphisms start to play an important role in evaluation of disease risk and progression. The occurrence of multiple variants of the same gene may contribute to differences in reactions to specific medications and sensitivity to carcinogens or DNA repair capacity. Our study demonstrated T81C polymorphism of H-RAS gene to have seemingly been associated with an increased risk of bladder cancer development.

Concomitance of oncogenic HPV types, CHEK2 gene mutations, and CYP1B1 gene polymorphism as an increased risk factor for malignancy

Introduction Urinary bladder carcinoma ranks the fourth position in malignancy incidence rates in men (6.1%) and the 17th position in women (1.6%). In general, neoplastic diseases should be approached from two perspectives: prevention with implementation of prophylactic measures and early diagnostics. Prophylactics is possible in the preclinical phase of neoplasm, being both justified and plausible in patients from high–risk groups. Thus, it is particularly important to select such groups, not only by referring to environmental carcinogenic factors (occupational and extra–occupational) but also from genetic predisposition, which may be conductive for neoplasm formation. The mutations / polymorphisms of CHEK2 and CYP1B1 genes predispose to neoplasm via multiorgan mechanisms, while the human papilloma virus (HPV) may participate in the neoplastic transformation as an environmental factor. Material and methods 131 patients with diagnosed urinary bladder cancer were qualified to the study. Mutations/polymorphisms of CHEK2 (IVS2 + 1G > A gene, 1100delC, del5395, I157T) and CYP1B1– 355T/T were identified by the PCR in DNA isolated directly from the tumor and from peripheral blood. The ELISA test was used for the studies of 37 HPV genotypes in DNA, isolated tumour tissue. Results 11 mutations of CHEK2 gene were found, 355T/T polymorphism if CYP1B1 gene occurred in 18 patients (12.9%). Oncogenic HPV was found in 36 (29.3%), out of 123 examined patients. Conclusions The concomitance of CHEK2 gene mutations or 355T/T polymorphism of CYP1B1 gene and the presence of oncogenic HPV types statistically significantly correlates with histological malignancy grades of urinary bladder carcinoma.

detection of loss of heterozygosity in patients with urinary bladder carcinoma: neoplastic tissue vs. urine sediment cells

Introduction Loss of heterozygosity (LOH) is frequently observed in urinary bladder neoplasms. In the reported study, an attempt was undertaken to determine the loss of heterozygosity of TP53(17p13), RB1(13q14), CDKN2A/ ARF(9p21) genes in DNA from neoplastic tissue, collected from patients with diagnosed urinary bladder carcinoma, and to compare the results with those of LOH evaluation in DNA isolated from urine sediment cells. Material and methods After isolation, DNA was amplified (PCR) by means of primers to five polymorphic microsatellite markers, the products being then separated on agarose gel. Following the method, a total of 125 DNA samples were obtained, isolated from neoplastic cells, together with 125 corresponding DNA samples, isolated from urine sediment cells. Results The loss of heterozygosity in at least one marker was identified in 39.2%. (49/125) of DNA from studied tumors and in 34.3% (43/125) of DNA samples, isolated from urine sediment cells. An analysis of LOH from the DNA, isolated from urine sediment cells, allowed for identification of 81.8% of neoplastic tumors with 99.7% specificity. Conclusions Our observations have demonstrated that LOH within 13q14, 17p13 and 9p21 loci is more often observed in clinically more advanced neoplasms. LOH in 17p13 locus is more frequently found in tumors at high histopathological stage, while in low-stage neoplasms, LOH is most often observed on chromosome 9. The high sensitivity (81.8%) and specificity (99.7%) of LOH studies in DNA, isolated from urine sediment cells, make this technique an advantageous, non-invasive method for detection and screening of bladder cancer.

Significance of CDKN2A gene A148T variant in patients with bladder cancer.

Objectives The A148T polymorphism of CDKN2A gene is observed in various neoplasms with the incidence rate of 3-35%, however, rather little is known either about the frequency of its occurrence or of its significance in urinary bladder carcinoma. Materials and methods DNA was isolated from blood of 156 patients with urinary bladder carcinoma (130 men). In histopathology, 84 cases were classified as G1, 42 as G2, and 30 as G3. The clinical stage was in 81 cases estimated at Ta and in 75 cases at T1-T4. A148T polymorphism was detected by the MSSCP technique and by sequencing. Results A148T polymorphism was identified in 9/156 urinary bladder carcinoma cases (only in men). The obtained results were compared with the polymorphism incidence for the Polish population, estimated by Debniak et al. The occurrence in the group of the bladder cancer patients turned out higher (5.77%) from that in the control group (2.89%) (G test, table 2×2: NBLADDER CANCER = 156, NCONTROL = 1210, G = 4.298, p <0.05). Conclusion Summing up and taking into account the analysis of clinical parameters and the age of the disease occurrence, the A148T polymorphism of CDKN2A gene was identified in the study group only in men, in whom the disease was diagnosed above the age of 60, while the diagnosed neoplasms were in the majority of cases characterized by higher clinical stages and higher grades of malignancy. This has been the first study that attempted to show a potential association between A148T alterations and an increased risk for bladder cancer development.

The prevalence of CHEK2 and CYP1B1 mutations/polymorphisms in urinary bladder cancer

This work was supported by the State Committee for Scientific Research (KBN Poland) grant No. N401 197 32/4212.

Artificial neural network in predicting bladder cancer recurrence

The more we learn about human genetics and human variation, the more apparent it becomes that our individual make-up has a noticeble impact on the effectiveness of medications. Urinary bladder cancer is the sixth leading cause of mortality due to malignant neoplasm among Polish man in Lodz region. Many genetic and epigenetic alterations have been identified that contribute directly to the development of bladder tumors. The aim of the project was the creation of the individual risk calculator of bladder cancer recurrence using available clinical data and the results of the long term genetic research.

The A148T variant of CDKN2A gene in bladder cancer

Results We found common polymorphic variants reported in the literature at codon 148 in exon 2 (Arg148Thr) and at nucleotides 500 and 540 in the 3’untranslated region which were not considered to be functional variants. We compared the obtained frequencies for the particular CDKN2A variants with the control group for the Polish population examined by Debniak and colleagues (Cancer Research 2005) and we found a significant difference in A148T polymorphism occurrence in the group of the bladder cancer patients (G test, table 2 ×2: NBLADDER CANCER =80, NCONTROL=1210, G=10.214, p g, Nt540c>t polymorphisms recorded in the group of the bladder cancer patients in our study is not different from those recorded in the control group. Conclusion The A148T variant of CDKN2A gene seems to be associated with an increased risk of bladder cancer development.