Cytogenetic profile of locally advanced and metastatic schistosoma-related bladder cancer and response to chemotherapy

Bladder cancer is a common malignancy in developing countries in which bladder infection with the parasite Schistosoma haematobium is prevalent. Several epidemiological, histopathological, and clinical characteristics of schistosoma-associated bladder cancer suggest that it is distinct from bladder cancer seen in other places in the world. The aim of this study was to extend establishing the cytogenetic profile of this type of malignancy in advanced and metastatic cases, and to demonstrate its relation to the end results of systemic therapy. Fluorescence in situ hybridization was applied to interphase nuclei to detect numerical chromosome changes in 41 patients with bladder cancer. Numerical chromosome aberrations were detected in 27 of 41 cases (66%). In 17 (41%) cases, a gain of chromosome 7 was observed, while losses in chromosomes 9 and 17 were detected in 20 (49%) and 18 (44%) cases, respectively. Loss of chromosome Y was detected in 7 of the 32 male patients included in this study (22%). There was a statistically significant association between stage of the disease and overall survival; Bajorin score and time to disease progression and overall survival; and between response to systemic therapy and time to disease progression and overall survival. The only chromosomal abnormality that had a significant relationship with overall survival was the gain of chromosome 4. When the genetic basis of schistosoma-associated bladder cancer is fully understood, new diagnostic and therapeutic strategies could be developed, which in turn may promote better clinical management and survival.