The cellular immune response to carcinoma of the urinary bladder: correlation to clinical stage and treatment.

The cell mediated immune response to carcinoma of the urinary bladder in man is influenced significantly by the tumour burden before treatment. Therapy appears to influence this response by causing alterations in the amount of tumour material in the body. Removal of tumour by surgery is seen to result in a loss of detectable CMI. Recurrence of tumour after surgery results in the reappearance of cytotoxicity. Treatment by radiotherapy also results in the eventual loss of CMI after the elimination of tumour material from the body. The loss of activity after radiotherapy, in the absence of tumour recurrence, occurs over a period of about 1 year. Expression of CMI is suppressed during radiotherapy but may return after treatment. Failure to develop lymphocyte cytotoxicity early after radiotherapy is related to the presence of metastases or residual tumour. Low levels of cytotoxicity during the first 9 months after therapy are associated with tumour recurrence. It may be inferred from this that CMI in the early post-irradiation phase has prognostic significance. The absence of CMI at this time reflects the presence of residual viable tumour in the body. The loss of response about 1 year after radiotherapy probably reflects the clearance of tumour-derived material from the body. The persistence or reappearance of cytotoxicity after this time is related to tumour recurrence. This test is therefore informative as to the presence or absence of tumour after surgery. With regard to radiotherapy, lymphocyte cytotoxicity can be seen to monitor the presence of viable tumour and tumour derived material in the body.