Prediction of recurrence in Ta urothelial cell carcinoma by real‐time quantitative PCR analysis: A microarray validation study

Abstract

Accurate prediction of tumor recurrence in patients with superficial urothelial cell carcinoma (UCC) might result in a significant reduction of invasive follow-up cystoscopies. A recent study identified a panel of 26 genes from a large cDNA microarray analysis of bladder tumors that discriminated between early-and late-recurring patients with superficial Ta tumors (Dyrskjøt et al., Nat Genet 2003;33:90-6). We aimed to validate this panel of genes in 44 primary Ta UCCs (23 and 21 tumors from patients with short or prolonged recurrence-free periods, respectively), by real-time quantitative PCR. Statistical analysis showed marginal significant different mRNA expression levels between the 2 patient groups. To evaluate a supplementary effect of genes for the identification of patients with short or prolonged recurrence-free intervals, forward logistic regression analysis was applied. This revealed that a combination of the expression profiles of the genes HNRPK, LTB4DH and ANP32B resulted in the best performance, although the combination only marginally increased the predictive value of HNRPK alone. Comparing the receiver-operating-characteristic curves for HNRPK expression among patients with short or prolonged recurrence-free periods, revealed an area under the curve of 0.696 (95% CI, 0.537-0.855). Using the median HNRPK expression level as cut-off, a sensitivity of 69.6% and a specificity of 71.4% were obtained for the identification of patients with short or prolonged recurrence-free periods, respectively. In conclusion, we were not able to confirm the microarray gene expression pattern of the 26 genes shown by Dyrskjøt et al. The discovery of accurate recurrence predictive markers, therefore, remains a challenge. ' 2006 Wiley-Liss, Inc.Key words: recurrence; urothelial cell carcinoma; real-time quantitative PCR; microarray; validation Urothelial cell carcinoma (UCC) comprises up to 95% of human bladder cancer. It originates in the urothelium, the layer of cells lining the inner bladder wall. The larger part of patients with UCC is diagnosed with superficial tumors, pTNM stages Ta and T1, of which the depth of organ invasion is limited to the stromal mucosa. These tumors can be removed relatively easy by transurethral resection. Unfortunately, 70% of these patients experience recurrences after tumor removal and some will show progression towards muscle invasive disease. This necessitates frequent examination of the bladder by cystoscopy, which is invasive and represents a burden to the patient. The monitoring of these patients also includes those who will remain recurrence-free for several years or even for the rest of their lives. This generates a substantial number of unnecessary cystoscopies, which may be prevented by accurate prediction of tumor recurrence (or nonrecurrence) in patients with superficial UCC.The current standards for the estimation of the risk of recurrence are tumor grade, size and multiplicity. 1-3 Although these factors are relatively accurate in the group of patients with superficial UCC,...

Gene Expression Signatures Predict Outcome in Non–Muscle-Invasive Bladder Carcinoma: A Multicenter Validation Study

“…Unfortunately, a signature for disease recurrence prediction did not show any correlation to clinical outcome. This observation has previously been reported by another group (16). The molecular signatures were able to classify tumors correctly, although the tumors used in this study were sampled in different countries with different freezing and RNA extraction procedures.…”

Prediction of recurrence in low and intermediate risk non-muscle invasive bladder cancer by real-time quantitative PCR analysis: cDNA microarray results

“…This study is a logic follow-up to identify molecular markers in very early stage of primary NMIBC that may predict its recurrence. If we define upregulated or downregulated genes of our study, several of them are common to genes published by other authors, but in general the analogy of the genes, presented here, is not so extensive with other studies [7,8,[10][11][12][13][14][15][16]. It may be caused by unique provenance 1, 2, 3, 12, 14, 15, 16, and 22, see Table 2).…”

“…Several expression microarray studies have been performed for prognostic purposes in primary NMIBC, but none has shown sufficient clinical evidence to clinical usage. Most of them are based on identification of genes in transgenic mouse models [10], specific bladder cancer cell lineages [11], biological material from advanced tumors comparing gene expression in invasive stage of tumor disease [12,13,14] or usage of different molecular biological methods [15].…”

“…The qRT-PCR provides the possibility of further studying the genes of interest identified by microarray in larges series. Moreover, qRT-PCR permits the analysis of a low amount of and even poor quality RNA [15].…”

Detailed Technical Analysis of Urine RNA-Based Tumor Diagnostics Reveals ETS2/Urokinase Plasminogen Activator to Be a Novel Marker for Bladder Cancer

“…Microarray gene expression analysis by Dyrskjøt et al (2 ), for example, revealed stage-specific gene clusters whose expression pattern allowed a classification of bladder cancer into 3 distinct histopathological groups: noninvasive Ta tumors, invasive T1 tumors, and T2-T4 tumors. However, validation of these consolidated findings via reverse transcription quantitative-PCR (RT-qPCR) 5 failed although the same sample material was used (3 ). The statistical basis, the RNA isolation procedure, and the stability of PCR amplicons, as well as the amount and particularly the quality of RNA, are some factors that influence the outcome of gene expression studies.…”