OBJECTIVES

: Diabetes treatments may influence the risk, development and cancer prognosis when it develops. There is epidemiologic and pathophysiologic evidence that metformin may have a protective effect for non-small cell lung cancer(NSCLC) patients. Our objective is to investigate the impact metformin and other antidiabetic drug medications (ADM) have on survival of diabetic NSCLC patients.

METHODS

: We conducted a nested case-control study utilizing Medicare claims from the Surveillance, Epidemiology, and End Results(SEER)-Medicare linked database(2007-2013). Overall survival was measured from date of incident metformin or other ADM to NSCLC diagnosis date. Kaplan Meier survival curves with log rank tests and multivariable Renyi test statistic were used to examine time to NSCLC. Cumulative drug exposures after NSCLC diagnosis were modeled as time-dependent covariates.

RESULTS

: Among 4,652 patients aged older than 66 years with type 2 diabetes (T2D) prior to diagnosis of NSCLC, 692 were incident metformin users and 161 were incident other anti-diabetic drug medication users. After matching, we identified 300 cases and 100 controls. The overall median survival was not significantly different in the metformin NSCLC group (1,334 days) compared to the other ADM NSCLC group (1,134 days;Renyi test statistic p<0.5784). In the secondary analysis, of patients with a diagnosis of NSCLC, after their NSCLC diagnosis, 196 beneficiaries were assigned to cases (n=98) and controls (n= 98). The overall median survival was longer in the Metformin NSCLC group (384 days) compared to the other ADM NSCLC group (428.5 days;Renyi test statistic p<0.4925).

CONCLUSIONS

: Findings from this retrospective observational study demonstrate that T2D NSCLC patients on metformin did not have a difference in survival compared to other antidiabetic drug medication patients. Oncologists should consider that comorbidity management will play an increasing role in health services, and healthcare providers and researchers must assess the complexity of managing and studying patients with complex medication conditions.