Background: Previous studies investigating the effect of increased dose intensity and chemotherapy-induced neutropenia in patients with advanced non-small cell lung cancer (NSCLC) have not consistently shown significant survival benefits.
Methods: This retrospective analysis reviewed the outcome of patients receiving palliative chemotherapy for advanced NSCLC (stages III-IV) at the Royal Marsden Hospital. Regimens included cisplatin or carboplatin with either vinorelbine or gemcitabine on days 1 and 8, every 21 days. Patients who received at least four cycles of chemotherapy were classified into groups based on dose intensity, dose reductions, and worst grade of neutropenia for a landmark analysis. Comparisons between these groups for time to progression and overall survival were made by standard univariate and multivariate methods.
Results: One hundred sixty-nine of a total of 190 patients who received more than four cycles of chemotherapy during the period between November 1998 and December 2008 were included. One hundred twenty-five (73.9%) patients received four chemotherapy cycles with the remaining receiving up to six cycles. The median relative dose intensity for platinum was 93.9% (62.1-102%) and for vinorelbine/gemcitabine was 91.7% (37.8-105%). Dose reductions were recorded in 64 patients (37.8%), and 65 patients (38.5%) had grades 3 to 4 neutropenia. There were no statistically significant differences in time to progression and overall survival between any of the subgroups.
Conclusions: This retrospective analysis demonstrates no significant relationship between survival and dose intensity (<90%), modest dose reductions (<20%), or chemotherapy-induced neutropenia in patients receiving standard doublet platinum containing chemotherapy in NSCLC.