Androgen deprivation therapy and survival in patients with lung cancer.

Abstract

1597 Background: The epidemiology of lung cancer differs between men and women. There exists significant evidence suggesting estrogens influence the pathophysiology of lung cancer, however the role of androgens remains unclear. This study was performed to determine if exposure to androgen deprivation therapy (ADT) has an effect on survival in male patients (pts) diagnosed with lung cancer. Methods: Using the population-based Manitoba Cancer Registry and Manitoba Health Administrative Databases, all pts diagnosed with lung cancer from January 1, 2004 to December 31, 2010 were identified. Information from the Drug Program Information Network (DPIN) and the Aria electronic record at CancerCare Manitoba were used to determine prescriptions filled for anti-androgens, 5-alpha reductase inhibitors and GnRH agonists as a measure of exposure (defined as having filled at least 2 prescriptions and/or bilateral orchiectomy). Multivariable analysis with Cox proportional hazards analysis was used to compare survival. Results: A total of 3018 men with lung cancer were identified between 2004 and 2010. Of these, 339 (10%) were identified as having used a form of ADT. The majority of pts received 5-alpha reductase inhibitors (85%), the most common being finasteride (80% of total). Multivariable analysis revealed that patients who received ADT prior to the diagnosis of lung cancer had no statistically significant difference in survival (HR: 0.97 p=0.69) compared to those who did not. Patients exposed to ADT after their diagnosis were found to have a significantly better survival than those not exposed (HR 0.36 p=0.0007). This effect was also seen in those who received ADT before and after diagnosis (HR 0.53 p<0.0001). Conclusions: In male pts diagnosed with lung cancer, exposure to ADT is associated with significantly better survival when compared with no exposure. This effect is only seen when some or all of the exposure has occurred after the diagnosis of lung cancer. This study supports the hypothesis that the androgen pathway plays a role in lung cancer pathophysiology, and that androgen deprivation may improve prognosis