Driver mutation profiles and clinicopathological correlation in pulmonary adenocarcinoma with a micropapillary...

Area of Science:

• Oncology
• Molecular Biology
• Genetics

Background:

• Pulmonary adenocarcinoma with a micropapillary component (PA-MPC) is an aggressive lung cancer subtype.
• The molecular landscape of PA-MPC remains incompletely understood.
• Identifying driver mutations is crucial for targeted therapy and understanding PA-MPC behavior.

Purpose of the Study:

• To elucidate the driver mutation profiles in PA-MPC.
• To compare mutation profiles between micropapillary (MPC) and non-micropapillary (non-MPC) components within the same tumors.
• To investigate the correlation between mutation status, MPC predominance, and overall survival.

Main Methods:

• Next-generation sequencing (NGS) and quantitative real-time polymerase chain reaction (qPCR) were used to analyze driver mutations in 50 PA-MPC cases.
• Sanger sequencing confirmed NGS/qPCR findings.
• Laser-capture microdissection (LCM) was employed to separately analyze paired MPC and non-MPC components in 10 selected cases.

Main Results:

• EGFR mutations were highly prevalent (76.0%) in PA-MPC, followed by KRAS (6.0%) and PIK3CA (2.0%). No BRAF, NRAS, ALK, or PDGFRA mutations were detected.
• EGFR mutations were more frequent in MPC-predominant cases (90%) compared to non-MPC-predominant cases (66.7%).
• Overall survival was significantly worse in the MPC-predominant group. LCM analysis revealed identical EGFR mutation profiles in both MPC and non-MPC components within individual tumors.

Conclusions:

• EGFR mutations are a frequent and significant molecular feature of PA-MPC.
• The driver mutation profile, particularly for EGFR, is consistent between micropapillary and non-micropapillary components within the same tumor.
• The presence and predominance of the micropapillary component may be associated with a poorer prognosis.