Prognostic significance of preimmunotherapy serum CA27.29 (MUC-1) mucin level after active specific immunotherapy of metastatic adenocarcinoma patients.

The TRUQUANT BR radioimmunoassay, which uses monoclonal antibody B27.29 to quantitate CA27.29 mucin antigen (MUC-1 gene product) in serum, has recently received Food and Drug Administration approval for predicting recurrent breast cancer in patients with stage II and III disease. The purpose of this study was to determine whether the new radioimmunoassay for serum MUC-1 has prognostic significance for patients with metastatic adenocarcinoma receiving active specific immunotherapy (ASI). Using 40 U/ml as the upper limit of "normal," patients with metastatic breast and ovarian cancer with a preimmunotherapy serum CA27.29 mucin > 40 U/ml (CA27.29 Hi patients) had a poorer survival than CA27.29 Lo patients (< or = 40 U/ml) after ASI. There was no significant correlation between preimmunotherapy CA27.29 serum levels and measurable tumor burden. The preimmunotherapy CA27.29 serum level was a predictor of poor survival of metastatic colorectal and pancreatic cancer patients independent of other prognostic factors. There seemed to be two populations of pancreatic cancer patients, separated at 60 U/ml serum CA27.29 (CA27.29 Hi versus Lo patients). A CA27.29 serum level of 22 U/ml separated patients with CA27.29 Hi vs. Lo colorectal cancer. Patients with CA27.29 Lo colorectal and pancreatic cancer survived longer after ASI compared with patients with CA27.29 Hi colorectal and pancreatic cancer, respectively. We suggest that various CA27.29 serum levels define poor prognosis patients (CA27.29 Hi secretors) versus good prognosis patients (CA27.29 Lo secretors) for different cancer types.