Loss of ARID1A expression is associated with poor prognosis in non-small cell lung cancer

Adenine-thymine-rich inactive domain-containing protein 1A (ARID1A) is a large subunit of the switch-sucrose nonfermenting (SWI-SNF) complex. ARID1A is considered to be a tumor suppressor in various cancers. We investigated the clinicopathological significance including prognosis of ARID1A expression in non-small cell lung cancer (NSCLC). ARID1A expression was studied by tissue microarray immunohistochemical analysis of 171 surgically resected NSCLC specimens including adenocarcinoma (ADC) and squamous cell carcinoma (SCC) on tissue microarray. Semiquantitative immunohistochemical score was obtained by multiplying the intensity and percentage scores. The overall score was further simplified by dichotomizing into either negative (score < 4) or positive (score ≥ 4) for each patient. The ARID1A-negative group revealed significantly higher correlations with male sex (p = 0.020), larger tumor size (p = 0.007), SCC than with ADC (p = 0.023) and smoking (p = 0.001). Univariate survival analysis showed that the ARID1A-negative group had a significantly shorter cancer specific survival than the ARID1A-positive group (p = 0.018). Multivariate survival analysis showed that ARID1A negativity (p = 0.022) were independent prognostic factors related with shorter cancer specific survival for NSCLC. In conclusion, Loss of ARID1A expression is a potential molecular marker to predictive of poor prognosis of NSCLC.