Background: Lung cancer is the most common cause of cancer deaths in the U.S. The burden is even more pronounced in veterans due to higher prevalence of smoking in this subset of the population. Since the 1980s, adenocarcinoma has become more common than squamous cell carcinoma (SCC). Some data show that this is not the case among veterans. In this study, we compare the distribution of lung adenocarcinoma and SCC in the veteran population with that of the general population. We also looked at the survival of patients with different histologies in the VA population.
Methods: The electronic charts of 649 patients diagnosed with non-small cell lung cancer (NSCLC) from January 2000 until December 2010 at the Albany Stratton VA Medical Center were retrospectively reviewed. Patient demographics, clinical characteristics, and survival data were collected. Data were entered and analyzed using SPSS (IBM, Armonk, NY). Survival was estimated using Kaplan Meier method. A value of P < .05 was considered statistically significant. Data were compared with data from the Surveillance, Epidemiology, and End Results database. The study was approved by the VA IRB.
Results: A total of 649 patients with NSCLC were included.The proportion of adenocarcinoma was significantly higher in the general population, while that of SCC was significantly higher in the VA population. There were no differences in chemotherapy, radiation therapy, surgery rates, and age at diagnosis among the different histologies in the VA population. Patients with adenocarcinoma presented more frequently with metastatic disease than did patients with SCC (45.4% vs 29.5%, P < .001). The 5-year survival rate tended to be higher in SCC than in adenocarcinoma (15.7% vs 13.0%, P = .325).
Conclusions: Our study showed a significant difference in histologic subtypes of NSCLC between veterans and the general population, with SCC having a higher incidence rate compared with that of adenocarcinoma among veterans. Adenocarcinoma tended to present at a more advanced stage than did SCC. However, this did not translate into a significant survival difference.
