The association of chemotherapy induced neutropenia on treatment outcomes in small cell lung cancer

Background: Chemotherapy induced neutropenia has been shown to be associated with improved treatment outcomes in selected solid tumours. We studied the association of chemotherapy induced neutropenia with treatment related outcomes in small. cell lung cancer(SCLC). Methods: This is a retrospective analysis of patients receiving chemotherapy for SCLC at the Royal Marsden Hospital, UK over an 8 year period. The chemotherapy included Carboplatin AUC 5, IV and Etoposide 100 mg/m(2) IV on day 1 and 100 mg/m(2) PO, B.I.D. on day 2 and 3 every 21 days. Patients were stratified into two groups (A) those experiencing grades 0-2 neutropenia and group (B) those experiencing grades 3-4 neutropenia. The outcomes studied were response rate, time to progression (TTP) and overall survival (OS). Results: 173 patients were studied. The median age 64 (range 39-83) and M/F ratio was 112:61. The response rates in groups A and B was 90% versus 90%, p = 1.0. The median TTP in groups A and B was 30 and 38 weeks, p = 0.05. The median OS in groups A and B was 47 weeks versus 60 weeks, p = 0.008. The differences in TTP and OS were not significant in patients with extensive stage disease. Conclusions: Occurrence of chemotherapy induced grade 3 or 4 neutropenia correlated with OS in patients with SCLC receiving carboplatin and etoposide chemotherapy. Trials exploring controlled, safe intra-patient dose escalation with the intent of achieving grade 3 or 4 neutropenia in patients with SCLC are warranted. (C) 2006 Elsevier Ireland Ltd. All rights reserved.