Outcomes of non-small cell lung cancer patients with adenocarcinoma histology compared with other histologies: SEER registry data 2004-2008.
e17560 Background: For convenience, the majority of lung cancers are commonly lumped together as non-small lung cancer (NSCLC). Patients with adenocarcinoma of the lung have a higher incidence of driver mutation as compared to those with squamous histology. In addition pemetrexed containing regimens have preferential activity in this histology and agents such as bevacizumab are administered to this subgroup only based on toxicity. The currentanalysis was performed to compare outcomes for patients in the SEER database between 2004 and 2008 with adenocarcinoma (Adenoca), squamous cell carcinoma (SCCA) and NSCLC not otherwise specified (NOS). Methods: Data for 161,175 patients was available in SEER database between 2004 and 2008 with 38 different histology ICD codes. 134,947 patients (83.7%) were included in the study. NSCLC NOS (ICD-3 8046) n=36,408, SCCA (ICD-3 8070) n= 36, 454 and Adenoca (ICD-3 8140) n=62,085. Overall survival (OS) and lung cancer specific survival (LCSS) were analyzed using cox proportional Hazard model for the 3 groups. Results: Patients in the three groups were age-matched. Male gender was more common in patients who had SCCA compared to Adenoca (62.6% vs. 49.5%). Percentage of poorly differentiated tumors was higher in patients with SCCA (35.9%) compared to NSCLC NOS (32%) and Adenoca (27.5%). SCCA had fewer stage IV patients at diagnosis (29.5%) vs. 51.4 % for NSCLC NOS and 45% for Adenoca. OS and LCSS are listed in the table below with Hazard ratio (HR) and p value. Total of 23.54% (n=31,768) patients underwent surgical resection. Stage I patients who underwent surgery (n=18,517) also had similar results. Conclusions: NSCLC patients who have adenocarcinoma histology have significantly better overall outcome when compared to other histologies. The difference is more pronounced in an earlier stage disease. [Table: see text]