Clinical Aspects of Inflammation in Non-small Cell Lung Cancer

Abstract: Lung cancer is the most common cause of cancer death worldwide, with about 1.2 million deaths every year. In Sweden, about 3500 new cases are diagnosed every year. The majority of patients presents with advanced non-small cell lung cancer (NSCLC) and is treated with palliative intent. Standard treatment in these patients in performance status 0-2 is combination chemotherapy. Radiotherapy may be added for palliative purposes. Median survival time with such treatment is 6-10 months. New treatment strategies are urgently needed. There is growing evidence for a link between cancer and inflammation and consequently, inflammation may be a possible target for the treatment of lung cancer.The aim of this thesis was to study clinical aspects of inflammation in non-small cell lung cancer. A central issue was to adapt the projects as close to clinical routine as possible.In a retrospective study of 289 patients (paper I), we investigated the prognostic value of Creactive protein (CRP), a nonspecific marker of systemic inflammation, and smoking in patients with advanced NSCLC treated with palliative first-line chemotherapy. We found that patients with elevated CRP values (≥10 mg/ml) and current smokers at onset of treatment had inferior survival compared to patients with normal CRP values and patients who were not smoking. CRP and smoking status were independent prognostic factors and provided additional information to established prognostic factors such as stage of disease and performance status.The expression of COX-2, an important enzyme involved in inflammation, was prospectively analysed in 53 patients with cytologically diagnosed lung cancer (paper II). The study showed that the analysis of COX-2 expression in cytological material is technically easy to perform with routine diagnostic methods and results in good quality slides. There was great variation in the proportion of COX-2 positive cells between the patients as well as in the intensity of staining between individual cells in many single cases.The major project (paper III) of this thesis was the CYCLUS study, an academic, randomised, double-blind, phase III trial. The scientific question was if addition of the COX-2 inhibitor celecoxib to first-line palliative chemotherapy would prolong survival in patients with advanced NSCLC. 316 patients were included at 13 centres in Sweden. There was no survival difference between the treatment arms. Celecoxib appeared to have more favourable effect on survival in women than in men, but the differences were not significant. Small but not statistically significant differences in global quality of life and pain were seen favouring the celecoxib group. No increased incidence of cardiovascular events was observed in the celecoxib group.