DECLINE OF POSTTREATMENT TUMOR-MARKER LEVELS AFTER THERAPY OF NONSMALL CELL LUNG-CANCER - A USEFUL OUTCOME PREDICTOR

Background. The assessment of treatment efficacy in nonsmall cell lung cancer (NSCLC) is limited by the lack of a dear association between clinical response and survival. The prognostic usefulness of treatment-induced tumor-marker declines in NSCLC has not been established. The authors investigated the prognostic significance of treatment-induced declination in tumor marker levels of carcinoembryonic antigen, CA 19-9, and CA 125 in a group of patients with NSCLC treated with a brief course of cisplatin-based chemotherapy. Methods. Eighty-three patients with NSCLC enrolled on 2 related treatment protocols had pretreatment tumor-marker determinations. Patients were restaged 10 to 12 weeks after study entry, and clinical and marker responses were determined. Results. Thirty-eight patients (46%) had elevated pretreatment tumor markers, 36 (42%) of whom were evaluable for both clinical and marker responses. Pretreatment, the latter 36 individuals had measurable or evaluable disease, and at least one elevated tumor marker (greater than twice normal); posttreatment, they had follow-up measurements of both parameters. Of the 36 patients, 8 had normalization of tumor marker levels, 13 had 50-99% marker level declination, and 15 had less than 50% or no declination. In the same group of 36 patients, there were, 1 patient with complete clinical response, 11 with partial response, 19 with stable disease, and 5 with progressive disease. Marker responses occurred with equal frequency in clinical responders and nonresponders. There was no association between clinical response and survival, but there was a strong association between marker response and survival. Conclusions. In patients with nonsmall cell lung cancer with elevated pretreatment tumor marker levels, treatment-induced marker level declination can be a surrogate indicator for survival.