Blood group antigen expression in frozen sections of presenting bladder cancer: 3-year prospective follow-up of prognostic value

Loss of blood group A antigen expression in bladder cancer caused by allelic loss and/or methylation of the ABO gene

Loss of ABO blood group antigen expression has been reported in transitional cell carcinoma (TCC) of the bladder. Synthesis of the ABO blood group antigen was genetically determined by allelic variants of the ABO gene assigned on 9q34.1. We analyzed loss of heterozygosity (LOH) and promoter hypermethylation of the ABO gene in TCC and compared them with alterations of A antigen expression in TCC, dysplasia and normal urothelium. A total of 81 samples of TCC of the bladder obtained from transurethral resection (TUR) (n=44) and radical cystectomy (n=37) were examined. Expression of the A antigen was evaluated by immunohistochemical staining (IHC) using anti-A antigen monoclonal antibody. LOH of the ABO gene locus was examined by blunt-end single-strand DNA conformational polymorphism (SSCP) analysis using flouresence-based auto sequencer. Promoter hypermethylation of the ABO gene were examined by bisulfite PCR-SSCP (BiPS) analysis and/or methylation-specific PCR (MSP). Loss of A allele and/or hypermethylation were significantly associated with abnormal expression of the A antigen in cases undergoing TUR (P=0.02) and radical cystectomy (P=0.0005). For the analysis of the concomitant dysplasia in 23 cases with TCC of the bladder, the expression of the A antigen was maintained, regardless of the A allelic loss or methylation status in the tumor. In conclusion, A allelic loss and hypermethylation in the promoter region of the ABO gene showed significant correlation with reduction of A antigen expression in TCC, while the expression of the A antigen is maintained in concomitant dysplasia or normal urothelium, suggesting that loss of the ABO gene and/or its promoter hypermethylation is a specific marker for TCC.

Determination of DNA ploidy and ABH antigen reactivity in both frozen and formalin-fixed bladder tumor tissue

In a prospective series of patients with transitional-cell bladder carcinomas, DNA ploidy and ABH antigen reactivity were determined in both frozen tissue and formalin-fixed paraffin blocks. ABH antigen measurement in frozen tissue was hampered by methodological problems, especially insufficient morphology, which made quantification difficult. In only 38/55 (69%) cases was the same ABH reactivity found. The knowledge of secretor status was not helpful in the interpretation of these results. In 53/59 (90%) cases the same DNA ploidy was achieved, resulting in good correlation between flow cytometric DNA measurements in formalin-fixed and frozen tissue. The deviations occurred mainly in cases exhibiting a tetraploid DNA profile. DNA assessments using image cytometry on imprints of fresh tissue was a rapid and reliable method in our hands, with identical results being obtained in 32/36 (89%) cases.

Immunohistochemical detection of beta-human chorionic gonadotropin in urothelial carcinoma

Histologic sections from the specimens of 60 patients with urothelial carcinoma were stained immunohistochemically to search for beta-human chorionic gonadotropin (B-HCG) production. There were 6 doubtful, 5 weak and 1 strong positive B-HCG stainings among 65 sections from 60 patients. De novo acquisition of B-HCG production capability of tumour cells seemed to be predictive for early haematogenous dissemination of the disease, but the data obtained in this particular study were insufficient to suggest B-HCG as a routine prognostic marker.

Bladder cancer

Bladder cancer is largely a preventable disease; epidemiologic studies indicate that the majority of cases occur as a result of cigarette smoking or occupational exposures. The impact of screening high-risk populations is uncertain, but prompt and early diagnosis is essential for optimal therapeutic results. The management of different stages of disease varies greatly and is currently in a state of evolution. The majority of cancers are superficial, of low malignant potential, and can generally be treated cystoscopically. Few studies have addressed whether intravesical therapy will prevent high-risk patients with superficial disease from developing muscle invasion or distant metastases. Controversy exists as to optimal management of patients with invasive cancers. Improvements in technique and methodologies of urinary diversion have made cystectomy more tolerable for patients. Although cystectomy remains the "gold standard," probably not all patients require it. The careful selection of those patients whose bladders can be preserved is currently being evaluated. Combination chemotherapy for patients with metastatic bladder cancer is very active, appears to prolong survival, and may offer durable remissions to some patients. Whether chemotherapy will permit greater numbers of patients with invasive bladder cancer to be cured and bladders preserved remains to be determined.