Accumulation of nuclear p53 and tumor progression in bladder cancer

Radical cystectomy for high risk patients with superficial bladder cancer in the era of orthotopic urinary reconstruction

BACKGROUND

Many patients with aggressive clinically superficial bladder cancer ultimately die of their cancer, due in part to resistance to undergo radical cystectomy. Radical cystectomy is usually curative for patients with pathologic superficial tumors. Orthotopic urinary reconstruction has lessened the morbidity and lifestyle changes in patients after cystectomy, and may increase patient acceptance of cystectomy as therapy for high risk superficial tumors.

METHODS

A retrospective analysis was performed on 182 patients with clinically superficial bladder cancer (Ta, Tis, T1) who had radical cystectomy between 1971 and 1989, to determine the incidence of pathologic upstaging and to assess overall survival, cause-specific survival, and recurrence free survival. Indications for cystectomy included failure of intravesical chemo- or immunotherapy, high grade lamina propria invasive tumors, presence of bladder diverticulae, spread of superficial tumors into the prostatic urethra, and endoscopically uncontrollable tumors.

RESULTS

Pathologic upstaging to muscle-invasive or metastatic tumors occurred in 34% of patients, and of these, only half remained organ confined. Metastases were present in 8% of patients at the time of cystectomy. Mucosa-confined tumors were upstaged only 19% of the time, whereas tumors demonstrating lamina propria invasion (T1) were upstaged 40% of the time. Pathologic upstaging to muscle-invasive or metastatic disease was significantly associated with a decreased probability of survival (P = 0.042). With a median follow-up of 7.2 years, overall survival was estimated to be 86%, 72%, and 47%, and recurrence free survival 90%, 83%, and 77% at 2, 5, and 10 years, respectively.

CONCLUSIONS

Pathologic upstaging to muscle-invasive or metastatic tumors occurs in one third of highly selected patients with clinically superficial bladder cancer who have had radical cystectomy, half of whom have extravesical disease. Survival is significantly decreased in this group of upstaged patients. With the alternative of orthotopic urinary diversion available to most men and women requiring cystectomy, radical cystectomy should be considered a viable alternative to continued conservative measures for selected patients with aggressive superficial bladder tumors.

Human bladder carcinoma cell lines as indicators of oncogenic change relevant to urothelial neoplastic progression

Analysis of human tumour-derived cell lines has previously resulted in the identification of novel transformation-related elements and provided a useful tool for functional studies of different genes. To establish the utility of such cell lines as indicators of change relevant to urothelial cancer, we have characterised the expression of five genes (p53, MDM2, Rb, E-cadherin, APC) within a panel of human bladder carcinoma cell lines. Using single-strand conformation polymorphism (SSCP) and direct sequencing, p53 mutations were identified in 7/15 (47%) cell lines reflecting events reported in bladder tumours. Immunohistochemical analysis of p53 in cultured cells and in paraffin-embedded sections of xenografts from the cell line panel revealed discordant results. An absence of p53 nuclear staining was associated with an exon 5 mutation in EJ and with multiple p53 mutations found in J82. Two cell lines positive for p53 staining in the absence of detectable mutation displayed overexpression of MDM2 (PSI, HT1197) in Western blot analysis. Loss or aberrant Rb expression was recorded in 5/15 (TCCSUP, SCaBER, 5637, HT1376, J82) cell lines. Absence of E-cadherin was recorded in 5/15 cell lines (TCCSUP, EJ, KK47, UM-UC-3, J82) with loss of alpha-catenin in immunoprecipitated E-cadherin complexes of CUBIII. Western blot analysis of APC revealed a truncated protein in 1/15 (CUBIII) cell lines. The characterisation of oncogenic events within this panel of human bladder carcinoma cell lines establishes a representation of change observed in bladder tumours and better defines the genotypic background in these experimental human cell models of neoplastic progression.

Alteration of the tumor suppressor gene p53 in a high fraction of hormone refractory prostate cancer

PURPOSE

We studied the role of p53 tumor suppressor gene alteration in prostate cancer progression by demonstrating a difference in abnormal p53 findings between early and hormone refractory disease.

MATERIALS AND METHODS

The study included p53 immunohistochemistry of 26 archival transurethral resection specimens from patients with radiation recurrent and hormone refractory disease, 27 untreated primary tumors and 8 untreated metastatic lesions. p53 mutation analysis of tumor deoxyribonucleic acid (DNA) from microdissected specimens was done by cold single strand conformational polymorphism and DNA sequencing.

RESULTS

Elevated p53 protein was present in 16 of 17 hormone refractory specimens (94%), 4 of 8 untreated metastatic tumors (50%) and 6 of 27 primary untreated tumors (22%). DNA analysis of representative specimens with elevated p53 confirmed p53 gene alterations in 9 of 11 cases (82%).

CONCLUSIONS

Our study revealed a clear progression of increased p53 alteration from untreated primary to hormone refractory disease (p < 0.00005).

Incidence of occult lymph node metastases in pathological stage C (pT3N0) prostate cancer

PURPOSE

To determine the incidence of occult lymph node metastases in patients with stage pT3N0 prostate cancer.

MATERIALS AND METHODS

Lymph nodes from 95 patients with stage pT3N0 prostate cancer were analyzed by immunohistochemistry for extrinsic epithelial cells using epithelial-specific monoclonal antibodies. The extrinsic epithelial cells were also tested for prostate specific antigen expression.

RESULTS

Occult lymph node metastases were identified in 15 cases (16%) and were more frequent in patients with high primary Gleason grade tumors and seminal vesicle invasion (p = 0.03). In all cases the extrinsic cells were of prostate origin based on prostate specific antigen expression.

CONCLUSIONS

Occult lymph node metastases can be detected in a substantial proportion of patients with stage pT3N0 prostate cancer, are associated with known predictors of disease progression, and may be useful in identifying patients at risk for recurrence and progression.