Expression of Biomarkers of Tumor Cell Plasticity in Lung Adenocarcinoma Isotypes
Omid Rouhi, Mark Pool, Leonidas D Arvanitis, Kelly A Kaiser, Diana Escarzaga, Emira Hadziahmetovic, Michael Liptay, Brett Mahon, Jeffrey A Borgia. Rush University, Chicago, IL
Background: Adenocarcinoma is the most common histologic subtype of lung cancer. The clinical course is different among individuals even in cases of the same histologic subtype, presumably due to heterogeneity within the biologic properties of tumor cells. Therefore, lung adenocarcinoma isotyping has recently been proposed as a means to better prognosticate clinical outcome and is encouraged to assist in better determine patient treatment options.
Design: Immunohistochemical staining for 13 different markers of tumor cell plasticity was performed on 65 primary lung adenocarcinoma and matching metastatic lymph nodes. Histologic isotyping was performed with acinar, papillary, and solid isotypes selected for further analysis based on their frequency.
Results: We observed approximately 21% discrepancy between primary and lymph node in presenting predominant isotype, but with no enrichment of any specific isotype in primary vs lymph node metastatic plaque. Solid type showed lower expression of sonic hedgehog compared to other forms in primary tumors. In lymph node, cytoplasmic OGT and CD133 were significantly lower in solid type. Although there was not an observed significant difference in overall survival and recurrence free survival among different isotypes. However, we observed a higher rate of recurrence (p=0.05), lower overall survival (p=0.036), and lower recurrence free survival (P<0.001) in cases where there was a discrepancy between primary and lymph node positive tumors.
Conclusions: This is the first study demonstrating differences in histologic subtype of adenocarcinoma in primary and lymph node metastases that can is correlated to patient outcome. Further validation of these results is currently underway with a larger, external cohort of patients.
Tuesday, March 20, 2012 1:00 PM
Poster Session IV # 312, Tuesday Afternoon