How does chronic obstructive pulmonary disease affect the survival of patients with stage 4 lung cancer?

Abstract

Lung cancer risk is increased in COPD. However, it is not clear how COPD affects the course of lung cancer. To determine whether the overall survival of stage 4 lung cancer patients differ in various COPD stages. A cross-sectional retrospective study. We screened lung cancer patients with ICD code: C34 and included stage 4 lung cancer patients with histological diagnosis and pulmonary function tests at admission in the study. Demographic data, stages, metastasis sites and number of metastases, performance status, pulmonary function tests, Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages, arterial blood gasses and treatment methods were recorded on a standardised database. We checked their dates of death from national database. Data were evaluated with SPSS programme version 18. Out of 900 patients, 146 patients had stage 4 disease at the time of diagnosis and, 127 patients had COPD. There was a significant difference between survivals of stage 4 cancer patients with different COPD stages. As COPD stage increased, overall survival worsened (P=0.037). Factors affecting survival were bone metastasis (P=0.01, OR=1.72), liver metastasis (P=0.04, OR=1.87), brain metastasis (P=0.001, OR=2.6), having N 2-3 disease (P=0.01, OR=1.79) and GOLD 4 COPD (P=0.01, OR=2.28). As COPD becomes more severe, overall survival rates of stage 4 patients worsen. Bone metastasis, liver metastasis, brain metastasis, having N2-3 disease and GOLD 4 COPD worsen the overall survival.