Three cases showed clear evidence for independent origin of two tumors by X-chromosome inactivation assay, which disproves a hypothesis that all bilateral breast tumors develop from a single transformed cell. Studying other genetic markers, such as new candidate tumor suppressor genes and genetic polymorphisms in the 'cancer susceptibility genes,' and their interactions with environme- ntal risk factors will eventually lead to better understanding of variability in cancer risk in the populations that cannot be explained by known environmental risk factors alone. Prognostic factors in bladder cancer are used to determine the prognosis of patients and select the method of treatment. Clinical stage, the number of tumors, size of the main tumor, mode of proliferation, cell type, histological grade, histological stage, mode of spread, and intramural lymphatic and venous invasion are well-known prognostic factors. They are closely related to survival or the disease-free interval.
Most prognostic factors are histopatho- logical findings.
Now, study of new prognostic factors in bladder cancer related to molecular biological or immunohistochemical technique is ongoing. To describe the incidence of, clinical manifestations of, and risk factors for cyclophosphamide-induced urinary bladder toxicity in patients treated for nonmalignant disease. Retrospective analysis of patients followed at the National Institutes of Allergy and Infectious Diseases from 1967 to 1993. Clinical characteristics, cystoscopic findings, results of cytologic examination of urine, surgical pathology, and total dose and duration of cyclophosphamide therapy were recorded and analyzed using a computer-based information retrieval system. In 6 of these 7 patients, the total cumulative cyclophosphamide dose exceeded 100 g, and the cumulative duration of cyclophosphamide therapy exceeded 2.7 years.