Survival at one year in patients with lung cancer in a tertiary care center

Abstract

Introduction: Lung cancer is a leading cause of mortality worldwide and despite advances in treatment, prognosis of advanced lung cancer is extremely poor, with a median survival time of approximately 1year. Factors like age, sex, performance status at the time of diagnosis, histological type, extent of disease, smoking status were found to predict survival in lung cancer.

Aim of the study: To determine one year survival of lung cancer patients from the date of diagnosis and to evaluate factors that are associated with survival.

Methodology: Prospective cohort study, conducted at Medical College, Thiruvananthapuram, Kerala, in 160 consecutive patients with histopathological diagnosis of lung cancer. Data on demography, symptoms, smoking status, performance status according to WHO performance scale, histological diagnosis, TNM stage and death were recorded using a structured questionnaire. Proportion of patients who survived at one year from the date of diagnosis was determined. For inferential statistics between groups, comparison of qualitative variables were analysed by chi-square test and quantitative variables were compared by student t test. P value of less than 0.05 was considered as level of significance Cox proportional hazard model were used to evaluate the factors affecting survival of lung cancer patients.

Results: 160 consecutive lung cancer patients with histopathological diagnosis were included in the study. 86.9% of patients were males. Male to Female ratio is 6.6: 1. 84. 5% of patients were above the age of 50 years. 11.3% were nonsmokers. COPD was the commonest comorbidity (58%) in the study. Adenocarcinoma (41.9%) was the commonest histological type in our study and this was the commonest histological type seen in females and nonsmokers. In smokers, squamous cell carcinoma (91.3%) was more common. 66.9% of patients were at TNM stage 3 or 4 at the time of diagnosis. 17.5% patients survived at one year after diagnosis. Age more than 70 years, high smoking index, associated COPD, TNM Stage 3 & 4, poor performance status at the time of diagnosis were associated with poor survival. (p value <0.001). Squamous cell carcinoma had better survival compared to other histological types (p< 0.001). No significant association between gender and survival pattern was seen in the study.

Conclusion: We found that 17.5% of lung cancer patients survived at one year after diagnosis. There was significant association of factors like age, smoking status, comorbidities, histological type, TNM stage and performance status at diagnosis with survival pattern. But no significant association between gender and survival was found in our study.