Purpose: This study investigated the accuracy of intraoperative frozen section (FS) diagnosis for predicting the final pathology (FP) of peripheral small-sized lung adenocarcinoma and evaluated its usefulness in sublobar resection.
Patients and methods: The records of 803 patients with clinical stage I peripheral lung adenocarcinoma who underwent sublobar resection for FS diagnosis to guide surgical strategy were reviewed. The surgical extension was mainly based on FS. The FS were stratified into atypical adenomatous hyperplasia, adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and invasive adenocarcinoma. The diagnostic accuracy of FS, the reasons for the discrepancy between FS and FP, and the clinical influence of the FS errors were evaluated. To assess the survival of patients with different subtypes after surgery, 301 patients were identified for prognosis evaluation.
Results: The total concordance rate between FS and FP was 84.4%. When atypical adenomatous hyperplasia, AIS, and MIA were classified together as a low-risk group, the concordance rate was 95.9%. Most discrepant cases were the underestimation of AIS and MIA. The diagnostic accuracy of FS for tumors ≤ 1 cm and larger than 1 cm in diameter was 79.6% and 90.8%, respectively (P < .01). The FS errors had significant clinical impact on 0.9% of the 803 patients due to insufficient resection. The 5-year recurrence-free survival rate (100%) was significantly better for the patients with AIS/MIA than for patients with invasive adenocarcinoma (74.1%, P < .01).
Conclusion: Frozen pathology has a high concordance rate with FP. Precise diagnosis by intraoperative FS is an effective method to guide resection strategy for peripheral small-sized lung adenocarcinoma.
© 2015 by American Society of Clinical Oncology.