EGFR mutation represented the most common driver alterations across AIS, MIA, and IAC, whereas tumor protein p53 gene (TP53) was identified in MIA and IAC but not in AIS.
DNA and immunohistochemical analyses revealed similar EGFR mutation rates in both MIA and AIS, suggesting that mutation-specific monoclonal antibodies are useful to confirm DNA assay results.
The remaining 26 quadruple-negative tumors were significantly associated with AAH/AIS (P < 0.01) and no-growth (P < 0.01) compared with driver mutation-positive tumors, whereas EGFR mutation-positive tumors were correlated with MIA/IA (P < 0.01) and growth (P < 0.01) compared with EGFR-negative tumors.
Although EGFR was expressed in invasive adenocarcinoma but not in adenocarcinoma in situ (AIS), USP8 was overexpressed in not only invasive adenocarcinoma but also 38.1% of AIS cases.