الفهرس | Only 14 pages are availabe for public view |
Abstract - Bladder carcinoma is the most common encologic problem in Egypt. Two different clinicopathological entities are generally recognized. namely: bilharzial and non - bilharzial types. The former type iasis which is is more associated with urinary schistosomcommon and affects farmers at a relatively young age. Transitional cell carcinoma of the bladder ’usually presents as localized superficial lesion in approximately 80 o of the cases. However • after initial management the recurrence rate ranges from’ 40 to 70 per cent. Several intravesical chemotherapeutic agents have been used either as a prophylactic or in the treatment of completely unresected tumor. More chemotherapedtic agents have been after transurethral resection and recently • used immediately fulguration to prevent implant&~ion of the tumor which may be responsible for recurrences. - 110 - Several clinical trials using new drugs have justified the increasing incorporation of intravesical chemotherapy into therapeutic programs for bladder cancer patients. Until recently, thio-tepa and ethoglucid were the only agents used and they were largely reserved for patients unsuitable for surgery • Treatment patterns are gradually changing on two levels. New agents such as mitomycin C and adriamycin have been introd~ced. These d rug s appear to produce higher objective response rates than thio - tepa with less toxicity. Although a prospective randomized study has yet to prove their superiority the excellent response rat e s achieved in patients failing thio - tepa therapy and the impressive complete and partial regression rates documented by several investigators suggest this advantage. Instillation of antitumor agents into the bladder within 48 hours of complete endoscopic excision of superficial tumors has been shown to - 111 - lengthen the tumor - free interval and reduce the recurrence rate. Although myelosuppression continues to be a therapy associated with risk when cytotoxic agents are instilled shortly after surgery , the degree of this effect seems to b e correlated with the molecular weight of the agent. It is hoped that this potential hazard will b e diminished or completely eliminated with the use of drugs that have s, higher molecular weight than thio - tepa. The relative risks of local and systemic side effects, for each drug need to be· determined. Information must be gained on each drug’s ability to enter normal or neoplastic urothelial cells. The role of urinary pH, bladder capacity and vesico-ureteric reflux must all be correlated with toxicity and response rates for each drug. The duration of treatment has been largely empirical and limited to 1 to 2 hr••:.varying this time may be fruitful. The frequency 0 f instillation has also varied , however, m 0 s t regimens rely on a weekly schedule. More frequent instillations might be more effective. The role - 112 - of continuous bladder irrigation has explored. A low drug concentration contact with the urothelium might ior effect. not been in prolonged provide superx: few agents , such as cisplatin and methotrexate , have been found consistently to induce clin-ically useful remission and a 9 - 12 months. Prolongation of life for responders compared to non - res~onders. Since cisplatin, methotrexate , adriamycin and probably mitomycin C have been shown to be effective anti-tumor agents for transitional cell carcinoma , patients with disseminated bladder cancer can now be considered for chemotherapy, where clinically appropriate. The a~m of immunotherapy is to stimulate the immune ~atem to eliminate an established tumor , prevent a recurrence • and prevent the development of a new tumor. Unfortunately, we still cannot predict with certadnty the effects of specific immunization in an individual patient with tumor. Both humoral and cellular immunity may be stimulated by a particular regimen and lead to enhancement of tumor growth by blocking antibodies rather than tumor destruction b y cytotoxicity and production of deblocking antibodies rather than blocking antibodies. ” |