Introduction: Patients with lung cancer have a high frequency of comorbidity. Data on the impact of diabetes mellitus, the most frequent endocrine disorder, on the prognosis of lung cancer are conflicting. The aim was to investigate the impact of diabetes mellitus on survival in lung cancer.
Method: We analyzed data from a cohort, the Nord-Trøndelag Health Study (HUNT study) linked to the Norwegian Cancer Registry and controlled the results using two lung cancer studies, the Pemetrexed Gemcitabine study and the Norwegian Lung Cancer Biobank. Survival in lung cancer with and without diabetes mellitus was compared using the Kaplan-Meier method and Cox regression model for each study and the studies combined.
Results: One thousand six hundred seventy-seven cases of lung cancer were included, 1031 from HUNT study, 436 from the Pemetrexed Gemcitabine study, and 210 from the Norwegian Lung Cancer Biobank registry, and among these 77 patients had diabetes mellitus. In the combined analysis, patients with lung cancer with diabetes mellitus had increased survival compared with those without (p = 0.005). The 1-, 2-, and 3-year survival in patients with lung cancer with and without diabetes mellitus were 43% versus 28%, 19% versus 11%, and 3% versus 1%, respectively. Adjusting for age, gender, histology, and stage of disease in the Cox regression model, the hazard ratio for survival in patients with lung cancer with diabetes mellitus was 0.55 (95% CI, 0.41-0.75) as compared with without.
Conclusion: Patients with lung cancer with diabetes mellitus have an increased survival compared with those without diabetes mellitus.