Androgen Pathway Manipulation and Survival in Patients with Lung Cancer

Abstract

The epidemiology of lung cancer differs between men and women. The role of androgens in lung cancer remains unclear. This study was performed to determine if exposure to androgen pathway manipulation (APM) is associated with greater survival in male patients diagnosed with lung cancer. Using a retrospective cohort design, all men diagnosed with lung cancer from January 1, 2004 to December 31, 2010 were identified from the population-based Manitoba Cancer Registry and Manitoba Health Administrative Databases. Information from the Drug Program Information Network (DPIN) was used to determine prescriptions filled for antiandrogens, 5-alpha reductase inhibitors, and gonadotropin-releasing hormone (GnRH) agonists. Multivariable Cox proportional hazards analysis with time-varying exposure variables was used to compare survival. A total of 3018 men with lung cancer were identified between 2004 and 2010. Of these, 339 (11.5 %) were identified as having used a form of APM. The majority of patients received 5-alpha reductase inhibitors. Patients who received APM prior to the diagnosis of lung cancer had no significant difference in survival (HR 0.97, p = 0.69) compared to those who did not. Patients exposed to APM after their diagnosis were found to have a significantly better survival (HR 0.36, p = 0.0007), as were those exposed both before and after diagnosis (HR 0.53, p < 0.0001). In male patients diagnosed with lung cancer, exposure to APM is associated with significantly better survival when compared with no exposure. The association is only seen when some or all of the exposure has occurred after the diagnosis of lung cancer.