Abstract
Background/Aims Bevacizumab has FDA approval for advanced stage (IIIB/IV) non-small cell lung cancer (NSCLC) treatment; however, little is known about its uptake and use in HMOs. The aim of this study was to examine bevacizumab use over time in 4 Cancer Research Network (CRN) HMOs and identify factors associated with its use.
Methods Patients aged ≥21 years with stage IIIB and IV NSCLC diagnosed between 2005–2010 at 4 CRN sites who received first-line carboplatin-paclitaxel with (CPB) and without bevacizumab (CP) were included in this retrospective cohort study. Information on patients’ comorbidity burden, sociodemographic, tumor, and chemotherapy treatment characteristics over time were obtained from the site’s Virtual Data Warehouse. Patient information was contrasted between CPB and CP patient groups using chi-square tests of association and t-tests/rank sum tests for nominal/ordinal and interval-level factors, respectively. Factors with a P <0.2 in the bivariate analyses and patient sex were included in a multivariate logistic regression model to identify factors independently associated with receiving first-line CPB with adjustment for the clustering of study site. Interactions of age and stage with other factors were assessed.
Results A total of 1109 patients were included with 198 (18%) and 911 (82%) in the CPB and CP groups, respectively. Patients who received CPB were more likely than patients who received CP to be younger with lower comorbidity burdens, well/moderate differentiated tumors, non-small cell carcinoma morphology, and diagnosed in the later years of the study (all P <0.05). Receiving CPB was associated with a non-small cell carcinoma morphology (OR = 1.84, 95% CI 1.21–2.80), well/moderate differentiated tumor (OR = 1.76, 95% CI 1.14–2.74), and diagnosis year (OR = 1.17, 95% CI 1.06–1.30) while inversely associated with age at diagnosis (OR = 0.96, 95% CI 0.95–0.98) (c-statistic = 0.738). No interactions were associated.
Conclusions Bevacizumab use in CRN patients with NSCLC was limited but uptake was associated with younger age and tumor factors, and increased over time. The patterns of CPB use in the CRN are consistent with published data that suggest little clinical advantage of bevacizumab in NSCLC patients ≥65 years and where approximately 2/3 of NSCLC patients are diagnosed at ≥65 years.
