USEFULNESS OF LONGITUDINAL EVALUATION OF CYFRA-21-1 VARIATIONS IN ADVANCED LUNG-CANCER MONITORING

To investigate the usefulness of Cyfra 21-1 as an indicator of therapy effectiveness and prognosis in advanced primary lung cancer, sixty-th ree patients were selected on the basis of a high Cyfra 21-1 serum lev el (> 3.3 ng/ml) at the time of diagnosis. Serial assays of Cyfra 21-1 were performed during the first three courses of chemotherapy among 6 3 patients. The serial values were analysed according to response to t reatment and overall survival. After three courses of chemotherapy, a 70% reduction under the initial marker's value or a return to normal w as observed for 36 patients. Twenty-two (61%) of these patients presen ted an objective response to therapy, making Cyfra 21-1 a moderate ind icator in terms of positive predictive value (PPV). However, a signifi cant decrease of Cyfra 21-1 was observed in 88% (sensitivity) of the 2 5 objective responders. Cyfra 21-1 changes after one course of chemoth erapy (61 patients) were not sufficient to predict the future response after three courses (sensitivity 52%, specificity 56%, PPV 45%). Amon g 30 clinical or radiological relapses, a 10% increase or a return upp er reference limit in Cyfra 21-1 level was observed in 18 cases (sensi tivity 60%, specificity 100%, PPV 100%). Survival data were available for 61 patients. No significant statistical difference (P > 0.05) was found between survival curves depending on a significant decrease of C yfra 21-1 after the first course of chemotherapy. We can conclude that the only interest of serial Cyfra 21-1 assays may be the detection of relapse, where one observes a significant decrease of the marker corr elated with an objective response to first treatment. (C) 1997 Elsevie r Science Ireland Ltd.