Response rate as an endpoint for evaluating new cytotoxic agents in phase II trials of non-small-cell lung cancer.
BACKGROUND
Response rate (RR) has been used as a defining endpoint of new-agent phase II trials for non-small-cell lung cancer (NSCLC). However, tumor responses to chemotherapy do not always result in prolonged survival of patients with this disease.


METHODS
Single-agent phase II trials were identified by a MEDLINE search of the period from 1976 to 1995. Associations between RR, median survival time (MST) and characteristics of patients who entered the trial, including tumor extent, performance status and prior chemotherapy, were studied by using the logistic regression model.


RESULTS
A total of 183 treatment arms in 176 trials (including 10 randomized phase II trials) were identified. The overall RR in the 6768 evaluable patients was 11%. Eleven drugs, cisplatin, epirubicin, ifosfamide, edatrexate, irinotecan, vinorelbine, docetaxel, paclitaxel, etoposide, vindesine, and 254-S, produced a RR of more than 20%. An MST of eight months or longer was obtained with 12 drugs, but there were cases in which no objective responses were produced by these drugs. MST was correlated with RR (r = 0.504, P < 0.0001), but ranged broadly at a given level of RR. Multiple linear regression analysis showed a significant correlation between RR and MST (regression coefficient = 0.60, P = 0.00003) after adjustment for other variables.


CONCLUSIONS
RR was significantly correlated with MST in single-agent phase II trials for NSCLC, but there is room for further consideration of the endpoint of these trials.
Sekine
I
I
Internal Medicine and Thoracic Oncology Division, National Cancer Center Hospital, Tokyo, Japan. isekine@gan2.ncc.go.jp
Kubota
K
K
Nishiwaki
Y
Y
Sasaki
Y
Y
Tamura
T
T
Saijo
N
N
D000970:Antineoplastic Agents / Q000627:therapeutic use*; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy*; D017322:Clinical Trials, Phase II as Topic; D003627:Data Interpretation, Statistical; D006801:Humans; D016014:Linear Models; D008175:Lung Neoplasms / Q000188:drug therapy*; D016019:Survival Analysis; D016896:Treatment Outcome
D000970:Antineoplastic Agents