Can Bcl-XL expression predict the radio sensitivity of Bilharzial-related squamous bladder carcinoma? a prospective comparative study

Local pelvic recurrence after radical cystectomy for muscle invasive bilharzial related squamous cell carcinoma accounts for 75% of treatment failures even in organ confined tumors. Despite the proven value of lymphadenectomy, up to 60% of patients undergoing cystectomy do not have it. These factors are in favor of adjuvant radiotherapy reevaluation. objectives: to evaluate the effect of adjuvant radiotherapy on disease free survival in muscle invasive bilharzial related squamous cell carcinoma of the urinary bladder and to test the predictability of radio-sensitivity using the anti apoptotic protein Bcl-XL. The study prospectively included 71 patients, (47 males, 24 females) with muscle invasive bilharzial related squamous cell carcinoma of the bladder (Stage pT2a-T3N0-N3M0) who underwent radical cystectomy in Assiut university hospitals between January 2005 and December 2006. Thirty eight patients received adjuvant radiotherapy to the pelvis in the dose of 50Gy/25 fractions/5 weeks (Group 1), while 33 patients did not receive adjuvant radiotherapy (group 2). Immunohistochemical characterization for bcl-xL expression was done. Follow up was done every 3 months for 12 to 36 months with a mean of 16 ± 10 months. All data were analyzed using SPSS version 16. Three years cumulative disease free survival was calculated and adjusted to Bcl-XL expression and side effects of the treatment were recorded. The disease free cumulative survival was 48% for group 1 and 29% for group 2 (log rank p value 0.03). The multivariate predictors of tumor recurrence were the positive Bcl-XL expression (odd ratio 41.1, 95% CI 8.4 - 102.3, p < 0.0001) and radiotherapy (odd ratio 0.19, 95% CI 0.05 - 0.78, p < 0.02). With Cox regression, the only independent multivariate predictor of radio-sensitivity was the Bcl-XL expression with odd ratio 4.6 and a p value < 0.0001. All patients tolerated the treatment with no life threatening or late complications during the period of follow up. Adjuvant radiotherapy for muscle invasive bilharzial related squamous cell carcinoma of the urinary bladder has potential effectiveness and minor side effects. Moreover, Bcl-XL expression is a valuable tool for predicting those who might not respond to this adjuvant treatment