Changing Patterns (Age, Incidence, and Pathologic Types) of Schistosoma-associated Bladder Cancer in Egypt in the Past Decade

Objective

To assess the patterns of schistosomiasis-associated bladder cancer in Egypt from 2001 to 2010 in a retrospective study. Bilharzial bladder carcinoma is the most common cancer, particularly in Egyptian men. Classically, carcinoma in a bilharzial bladder is most commonly of the squamous cell type. During the past decade, certain changes have occurred in the features in Schistosomiasis-associated carcinoma in Egypt with a decline in the frequency of squamous cell carcinoma and increase in the frequency of transitional cell carcinoma.

Methods

This was a retrospective study of 1932 patients treated at Kasr Al Aini Hospital, Cairo University, from 2001 to 2010. Two groups were selected: group 1 included 1002 patients from 2001 to 2005 and group 2 included 930 patients from 2006 to 2010.

Results

The mean patient age increased from 41 ± 11.2 years to 52 ± 8.6 years, and the male/female ratio changed from 5.6:1 to 4.2:1. The incidence of associated bilharziasis decreased from 80% to 50%. A significant increased occurred in transitional cell carcinoma from 20% to 66%, with a significant decrease in squamous cell carcinoma from 73% to 25%. No difference was observed in the tumor stage or grade or incidence of lymph node metastases between the 2 groups.

Conclusion

The pattern of incidence of the various histologic types of bladder cancer have changed, with most cases now transitional cell carcinoma, in contrast to the findings in the earlier Egyptian series. Additional studies are encouraged to explain the factors explaining these changes.