Changes in the natural history of nonsmall cell lung cancer (NSCLC)--comparison of outcomes and characteristics in patients with advanced NSCLC entered in Eastern Cooperative Oncology Group trials before and after 1990

Abstract

Background: Demographic factors and treatment regimens were evaluated in relation to differences in outcome between patients with advanced nonsmall cell lung cancer (NSCLC) who were diagnosed and treated on Eastern Cooperative Oncology Group Phase II and III trials from 1981 to 1990 and from 1991 to 2000.

Methods: In this retrospective analysis, 6 advanced NSCLC trials were identified between 1981 and 1990, and 3 trials were identified after 1990. Patient characteristics (n = 3398 patients) and other clinical outcomes were analyzed, including progression-free survival (PFS) and overall survival (OS).

Results: Patients who entered on trials after 1990 more likely were women, received a cisplatin-containing regimen, had a performance status of 0 or 1, had Stage IIIB (vs. Stage IV) disease, had tumors with adenocarcinoma histology, had weight loss < or = 10%, and had pulmonary-only metastases (although more total metastases and brain metastases) compared with patients who were diagnosed before 1990. OS was longer post-1990 than pre-1990 (8.2 months vs. 5.8 months pre-1990), and PFS was longer post-1990 (3.5 months vs. 2.6 months pre-1990; P<.001 for both). In addition, the median interval from the date of disease progression to death increased by nearly 62% in the later decade.

Conclusions: Improved survival in more recent NSCLC trials was explained in part by the enrollment of patients with more favorable prognostic factors. A change in the natural history of the disease was reflected by some of these changes, including increased numbers of women with the disease and changes in the patterns of metastases. Changes in eligibility criteria also accounted for some improvements in prognostic factors and improved second line therapies in the later decade. Thus, the survival improvements are likely to be multifactorial, with improved therapies also playing a major role.