Background: Distant metastasis is rarely described among bilharzial bladder cancer patients. However, with improved 5-year survival rates following adjuvant local therapy, distant metastasis is now reported with increasing frequency.
Methods: Three-hundred-fifty-seven bilharzial bladder cancer patients were treated at the National Cancer Institute in Cairo, Egypt, during the period 1981-1990. They were treated with either cystectomy alone, cystectomy preceded by a short course of preoperative radiotherapy (2000 cGy/5 fractions/1 week), or cystectomy followed by postoperative irradiation (5000 cGy/25 fractions/5 weeks or 3750 cGy/30 fractions/2 weeks). These patients were retrospectively analyzed.
Results: The overall 5-year actuarial rate of distant metastasis was 23% (95% confidence interval, 21-25%), which was essentially the same in the 3 therapeutic groups. Both univariate and multivariate analyses revealed that the independent risk factors for distant metastasis were pelvic lymph node involvement (P = 0.005), pathologic stage (P = 0.004), and histopathologic grade (P = 0.05). Histologic type and local pelvic recurrence appeared in the univariate analysis as working risk factors; however, they were proven by multivariate analysis to be dependent on other risk factors. Patients who had none of the independent risk factors had a lower rate of distant metastasis (II%) and a high local control rate (88%). Those who had more than one risk factor had high distant metastasis rate (51%) and low local control rate (41%), regardless of the therapeutic modality used. The identified independent risk factors determined both the distant metastasis and the local control rates.
Conclusions: Unlike previous reports, this rigorous study of distant metastasis in bilharzial bladder cancer revealed an occurrence rate of 23%. This high rate was associated with pelvic lymph node involvement, pathologic stage, and histopathologic grade. Histologic type, local pelvic recurrence, or the addition of pre- or post-operative radiotherapy proved not to be independent risk factors.