MEASURABLE OR ASSESSABLE DISEASE IN LUNG-CANCER TRIALS - DOES IT MATTER

Purpose: The goals of this study were to analyze and compare the major clinical response rates and survival of patients with either measurab le or assessable disease status to treatment with systemic chemotherap y. Patients and Methods: All patients had stage IIIB or IV non-small-c ell lung cancer (NSCLC) and were enrolled onto three consecutive phase III clinical trials. Patients were stratified by disease status (meas urable or assessable) before randomization to systemic chemotherapy. T he three trials were conducted in the setting of a multicenter coopera tive oncology group. Composite data were obtained for the three trials . Major clinical responses, time to progression, and survival were ana lyzed and compared in patients with measurable or assessable disease u sing standard statistical methods. Results: Four hundred twenty-six pa tients were enrolled the three trials from June 1981 through August 19 90. Measurable disease was present in 236 patients (55%) and assessabl e disease in 190 (45%). Each study was well balanced for the number of patients with measurable or assessable disease on either treatment re gimen. A major clinical response was observed in 71 patients with meas urable disease (30%; 95% confidence interval [CI], 24 to 36). Forty pa tients with assessable disease responded to treatment (21%; 95% CI, 16 to 28) (P = .04). The time to progression for all patients (P = .23) and for responders only (P = .10) was not significantly different base d on disease status. Overall survival and survival of responders only was not significantly different but patients with assessable disease t ended to do better. Using multivariate analysis, sex and disease statu s had a borderline influence on the major response rate (P = .05). Per formance score (PS) was the only factor that was significantly correla ted with survival. Conclusion: NSCLC patients with assessable disease have major clinical response rates, time to progression, and survival that are similar to those of NSCLC patients with measurable disease. T his study supports the inclusion of patients with assessable-disease l ung cancer in both phase II and III trials conducted in the cooperativ e group setting.