Low Survival in Poor Prognosis Metastatic Germ Cell Cancer in Belarus

PURPOSE

Since the development of the International Germ Cell Cancer Collaborative Group (IGCCCG) risk classification in a 1997 study, high-income countries have reported a significant increase in survival for poor prognosis patients. There are scant data on IGCCCG risk-stratified survival from low- and middle-income countries. We assessed the progression-free survival (PFS) and overall survival (OS) rates in a contemporary cohort of Belarusian patients with advanced germ cell cancer (GCC) stratified by the IGCCCG prognostic classification and analyzed prognostic factors for survival.

MATERIALS AND METHODS

The consecutive cohort of patients with clinical stage IIb-III testicular GCC or extragonadal germ cell tumors who received treatment or consultation in our two centers between 2010 and 2015 was included. All patients underwent primary chemotherapy. The patients were divided into seminoma and nonseminomatous germ cell carcinoma (NSGCC) subgroups. The Kaplan-Meier method was used to estimate 5-year PFS and OS.

RESULTS

This study included 111 patients with a median age of 32 years, 95% of whom were diagnosed with testicular cancer. Seminoma and NSGCC were identified in 32 (29%) and 79 (71%) patients, respectively. The median follow-up was 6.1 years. The 5-year PFS and OS rates for the entire cohort were 70% and 77%, respectively. In patients with good prognosis seminoma and good, intermediate, and poor prognosis NSGCC, the estimated PFS rates were 76%, 88%, 74%, and 39% and those for OS were 83%, 97%, 83%, and 38%, respectively.

CONCLUSION

In our cohort of Belarusian patients with advanced germ cell tumors, we failed to demonstrate an improvement in PFS and OS compared with the 1997 IGCCCG study. Moreover, survival in poor prognosis group is inferior to that in IGCCCG and all contemporary series from high-income countries.

Long-term results of a single-center prospective randomized trial assessing efficacy of a shortened course of adjuvant chemotherapy after radical cystectomy in patients with locally advanced bladder cancer

Introduction

This study assesses the efficacy and tolerability of two cycles of adjuvant chemotherapy (AC) with gemcitabine and cisplatin after radical cystectomy in patients with a high risk of progression of muscle-invasive urothelial bladder cancer as compared to chemotherapy at relapse, in a prospective randomized study.

Material and methods

From 2008 to 2013, all patients after radical cystectomy at our institution for primary or recurrent urothelial bladder cancer with stage pT3-4 and/or pN+ on histopathology and without contraindications to combination cisplatin-based chemotherapy, were randomized either to two cycles of gemcitabine and cisplatin chemotherapy or to follow-up and chemotherapy at the time of relapse. The study endpoints were overall, cancer-specific, and disease-free survival.

Results

The study included 100 patients, of whom 53 received AC and the other 47 were assigned to the control arm. Out of 53 allocated to AC arm, 16 patients did not start chemotherapy or received only one cycle of AC. The median follow-up for patients in the AC and control arms was 88 and 86 months, respectively. In the AC arm the hazard ratio for death from any cause, death from bladder cancer, and disease relapse were 0.70 (95% CI 0.45-1.11; p = 0.13), 0.84 (95% CI 0.50-1.41; p = 0.51), and 0.77 (95% CI 0.46-1.28; p = 0.31), respectively.

Conclusions

Two cycles of AC with gemcitabine and cisplatin in patients with high-risk urothelial bladder cancer after radical cystectomy does not improve overall, cancer-specific, and disease-free survival. Only 53% of patients randomized to AC received the entire planned treatment.

The Involvement of ERCC2/XPD and ERCC6/CSB Wild Type Alleles in Protection Against Aging and Cancer

BACKGROUND

DNA helicases maintain genome stability, and their deficiency is associated with disorders resembling premature aging as well as contributes to carcinogenesis. Their functions are determined by the respective genes encoding nucleotide excision repair initiating proteins, e.g. XPD and CSB.

OBJECTIVE

The present study aimed to investigate the influence of genetic variations in ERCC2/XPD (rs1799793, rs13181) and ERCC6/CSB (rs2228526, rs2228528) loci on lifespan and developing age-related bladder cancer focusing on homozygous wild type alleles.

METHOD

The allelic variants were identified in 354 clinically healthy controls and 418 bladder cancer patients using the PCR-RFLP method.

RESULTS

The age-depended increase in frequencies of homozygous carriers of wild-type XPD 312Asp and XPD 751Lys alleles was observed among controls, especially among subjects over 80 years (r = 0.67, p = 0.012). The statistically significant correlation was also found between the frequency of homozygous wild type alleles at all tested loci and age in healthy population over 60 years (r = 0.35, p = 0.046) suggesting the relationship between lifespan and longevity, on one hand, and normal functioning of these genes and their products, on the other hand. Homozygous carriers of wild type alleles were less susceptible to bladder cancer, tumor invasion, increase in grade of malignancy and recurrence, but their effects were specific with respect to clinicopathological and lifestyle characteristics.

CONCLUSION

Homozygous wild type alleles encoding XPD and CSB proteins with optimal properties were shown to affect human lifespan, risk of developing bladder cancer, its progression and recurrence under certain conditions.

BER gene polymorphisms associated with key molecular events in bladder cancer

AIM

Base excision repair (BER) gene polymorphisms are known to play an independent role in predisposition to developing different cancers as well as to be associated with clinicopathological traits of the disease modifying its clinical outcomes. One of the underlying mechanisms is presumed to include interplay between BER gene polymorphisms and key mutational, epigenetic and chromosomal events in tumor tissues. The present study was aimed at elucidating potential gene-gene interaction and assessing their mutual effects in bladder cancer (BC).

MATERIALS AND METHODS

The earlier obtained data on genotyping patients with verified diagnosis of BC for OGG1 rs1052133 (Ser326Cys) and XRCC1 rs25487 (Arg399Gln) polymorphisms were used for this study. The tumor tissue samples from the same patients were analyzed for mutations, epigenetic variations and losses of heterozygosity in some key genes involved in divergent pathogenic pathways of BC.

RESULTS

It was shown that the OGG1 (326 codon) heterozygous genotype as well as the minor 326Cys allele can intensify a mutational response of the RAS locus in urothelial carcinomas in the total cohort of patients simultaneously decreasing the mutation rates in the PIK3CA locus in smokers. The XRCC1 (399 codon) heterozygous genotype as well as the minor 399Gln allele reduced the frequency of LOH in the PTEN and TNKS genes, but did not affect the mutational variability in any locus tested. Both polymorphisms influenced the methylation status, carriers of OGG1 326Ser/Cys or Ser/Cys+Cys/Cys genotypes demonstrating increased frequency of methylated RUNX3 and ISL1 genes whereas the similar effect of XRCC1 polymorphism concerning methylation of p16 and TIMP3 genes. When dividing the total cohort into groups based on the extent of tumor spread, the observed associations were characteristic of non-muscle invasive BC.

CONCLUSION

The BER gene polymorphisms contributed to modification of key molecular events in urothelial carcinomas. Their mutual effects mainly manifested in non-muscle invasive BC. The underlying mechanisms as well as possible clinical outcomes need to be further explored to propose novel prognostic biomarkers for BC.

[A systematic review and meta-analysis to assess the recurrence-free survival in non-muscle invasive bladder cancer after transurethral resection guided by 5-aminolevulinic acid-induced photodynamic diagnosis compared with white-light transurethral resect]

INTRODUCTION

We conducted a meta-analysis assessing the effect of photodynamic diagnosis (PDD) -guided transurethral resection of the bladder tumor (TURB) on the recurrence-free survival in patients with non-muscle invasive bladder cancer within prospective randomised trials that used 5-aminolevulinic acid as a photosensitizer.

MATHERIAL AND METHODS

Medical literature search was performed up to February 2016. Recurrence hazard ratios (HRs) and its 95% confidence intervals (CI) were calculated for each selected study with direct and indirect methods and the pooled estimates were obtained with random-effects model.

RESULTS

Data from 5 prospective randomized trials with inclusion of 1089 patients were selected. Pooled estimate of recurrence HR was 0.71 (95% CI 0.48-1.04, p=0.08) with significant heterogeneity across selected publications: p=0,001; I2=78%. The subgroup analysis substantially reduced the heterogeneity: in subgroup comprising single/two-center studies or with moderate to high risk of bias or with long follow-up there was significant benefit of PDD-assisted TURBT (HR 0.51, 95% CI 0.38-0.69; p<0.0001), while in multicenter studies or those with low risk of bias or short follow-up the effect size was within the statistical error limits (HR 1.04, 95% CI 0.77-1.42, p=0.78).

CONCLUSIONS

Statistically significant benefit of PDD-guided TURBT over the white-light TURBT was limited to single/two-center studies or with moderate to high risk of bias or with long follow-up. True meaning of these finding it is not clear due to possibility of alternative explanations of identified differences. Generally there was low quality of evidence from significant proportion of studies and risk of publication bias.

[The criteria of patient selection for repeat transurethral resection of non-muscle invasive bladder cancer]

AIM

To evaluate in a prospective study the results of transurethral resection (TUR) for non-muscle invasive bladder cancer (NMIBC) and analyze the prognostic factors for the detection of residual tumor to develop indications for this intervention.

MATERIALS AND METHODS

The study included 111 patients with primary or recurrent NMIBC and intermediate or poor prognosis after visually radical TUR of the bladder. All patients underwent repeat TUR, which included a thorough cystoscopy, biopsy or TUR of all suspicious areas of the bladder, a deep biopsy of the area of the previous resection including the muscular layer. All prognostic tumor characteristics for assessing risk factors were available in 81 patients.

RESULTS

In total, repeat TUR resulted in the detection of 29/111 (26.1%) malignant tumors, while muscle-invasive cancer was diagnosed in 4/29 cases (3.6% of all included patients). The analysis of the relationship of residual tumor detection with various factors showed that the results of repeat TUR correlated with cystoscopic data at the repeat intervention and the degree of the tumor differentiation. Stratification of data depending on these factors revealed that in the absence of a visible tumor and G1, residual tumor was detected in 3.5% of cases, compared with 28.1% for the negative cystoscopy and G2-G3, and 52.6% for the positive cystoscopy regardless of G.

CONCLUSIONS

Cystoscopy may be applied for selecting NMIBC patients with G1 differentiation for repeat TUR. In the absence of cystoscopic confirmation of tumor, the repeat TUR can be avoided.

FGFR3 and TP53 mutations in a prospective cohort of Belarusian bladder cancer patients

AIM

The aim of this study was to determine the frequencies of FGFR3 and TP53 mutations in a prospective cohort of 150 bladder cancer patients and to assess the relationship between their mutational status and clinicopathological variables.

MATERIALS AND METHODS

The FGFR3 and TP53 mutations were detected by the SNaPshot method and PCR-single-strand conformational polymorphism analysis followed by DNA sequencing.

RESULTS

The activating FGFR3 mutations were found in 71 (47.3%) whereas TP53 mutations were observed in 31 (20.7%) urothelial carcinomas. FGFR3-mutant tumors significantly correlated with lower tumor stage and grade, papillary form of bladder cancer and the absence of metastases while TP53-mutant tumors were strongly associated with higher tumor stage and grade as well as the presence of metastasis. We also found significant inverse correlation between FGFR3 mutations and TP53 alterations in urothelial carcinomas (p=0.03). Four possible genotypes were observed in the whole studied cohort, namely FGFR3mut/TP53wt (41.3%), FGFR3wt/TP53wt (38%), FGFR3wt/TP53mut (14.7%), and FGFR3mut/TP53mut (6%). Tumors with FGFR3wt/TP53wt genotype comprised the subgroup, in which all stages and grades were equally distributed.

CONCLUSIONS

Our findings confirm the alternative role of FGFR3 and TP53 mutations in the development of bladder cancer. Together these two genetic markers are attributed to 62% of the tumors studied. Tumors with both wild type genes included urothelial carcinomas of all stages and grades and may develop through another genetic pathway. To elucidate complete molecular profile of bladder tumors further additional studies are needed.

Polymorphism of DNA repair genes OGG1, XRCC1, XPD and ERCC6 in bladder cancer in Belarus

CONTEXT

The study of DNA base and nucleotide excision repair gene polymorphisms in bladder cancer seems to have a predictive value because of the evident relationship between the DNA damage response induced by environmental mutagens and cancer predisposition.

OBJECTIVE

The objective was to determine OGG1 Ser326Cys, XRCC1 Arg399Gln, XPD Asp312Asn, and ERCC6 Met1097Val polymorphisms in bladder cancer patients as compared to controls.

METHODS

Both groups were predominantly represented by Belarusians and Eastern Slavs. DNA samples from 336 patients and 370 controls were genotyped using a PCR-RFLP method.

RESULTS

The genotype distributions were in agreement with the Hardy-Weinberg equilibrium. The minor allele frequencies in the control population were in the range of those in Caucasians in contrast to Asians. The OGG1 326 Ser/Cys and XPD 312 Asp/Asn heterozygous genotypes were inversely associated with cancer risk (OR [95% CI] = 0.69 [0.50-0.95] and 1.35 [1.0-1.82], respectively). The contrasting effects of these genotypes were potentiated due to their interactions with smoking habit or age.

CONCLUSIONS

Among four DNA repair gene polymorphisms, the OGG1 326 Ser/Cys and XPD 312 Asp/Asn heterozygous genotypes might be recognized as potential genetic markers modifying susceptibility to bladder cancer in Belarus.

[Modeling of phlebothrombosis in experimental animals]

Phlebothrombosis model was elaborated in experiment. The thrombotic mass was obtained in vitro, mixing the blood of animal with thrombin. Retracted thrombus was injected by puncture into previously ligated segment of the dog's v. jugularis externa. The vein's preparation was studied up on 1, 3, 5, 7, 10th and 14th day. Up to 8-10 days the thrombus adherence to the vein wall is friable and it is possible to extract it with the help of balloon catheter. Endothelium desquamation was revealed starting from 3-5th day.