Prognostic factors for long term survival in patients with advanced non-small cell lung cancer

Background: Non-small cell lung cancer (NSCLC) represents 85% of all lung cancers. It is estimated that 60% of patients with NSCLC at time of diagnosis have advanced disease. The aim of this study was to investigate clinical and demographic prognostic factors of long term survival in patients with unresectable NSCLC. Methods: We retrospectively reviewed data of 1,156 patients with NSCLC stage IIIB or IV who survived more than 60 days from the time of diagnosis and treated from August 1987 until March 2013 in the Oncology Department of Pulmonary Clinic of the General Hospital Papanikolaou. Initially univariate analysis using the log-rank test was conducted and then multivariate analysis using the proportional hazards model of Cox. Also Kaplan Meier curves were used to describe the distribution of survival times of patients. The level of significance was set at 0.05. Results: The mean age at diagnosis was 62 years. About 11.9% of patients were women and 88.1% were male. The majority of cases were adenocarcinomas (42.2%), followed squamous (33%) and finally the large cell (6%). Unlike men, most common histological type among women was adenocarcinoma rather than squamous (63% vs. 10.9%). In univariate analysis statistically significant factors in the progression free survival (PFS) and overall survival (OS) were: weight loss >= 5%, histological type, line 1 drugs, line 1 combination, line 1 cycles and radio lung. Specifically radio lung gives clear survival benefit in the PFS and OS in stage IIIB (P=0.002) and IV (P<0.001). On the other hand, the number of distant metastases in stage IV patients did not affect OS, neither PFS. In addition patients who received platinum and taxane had better PFS (P=0.001) and OS (P<0.001) than those who received platinum without taxane. Also the third drug administration proved futile, since survival (682.06 +/- 34.9) (P=0.023) and PFS (434.93 +/- 26.93) (P=0.012) of patients who received less than three drugs was significantly larger. Finally, large cell carcinoma recorded the shortest OS and PFS compared with adenocarcinoma (P=0.043 and P=0.016 respectively) and squamous cell carcinoma (P=0.021 and P=0.004 respectively). In multivariate analysis the same predictors were statistically significant except for line 1 drugs. Conclusions: This study confirms the increased incidence of adenocarcinoma in women than in men and the aggressiveness of large cell carcinoma. It also underlines the vitality of factors such as weight loss, radio lung and doublet platinum-based. On the other hand, it excludes significant factors such as gender, age and smoking.