Histological subtyping of non-small cell lung cancer using transbronchial biopsy specimens obtained with a small forceps

Introduction: Thin/ultrathin bronchoscopy with a small 1.5 mm biopsy forceps is useful for diagnosing peripheral lung cancer. However, it is unclear whether specimens sampled with small forceps are suitable for determining histological subtypes, which has become indispensable for making management decisions in patients with non-small cell lung cancer (NSCLC). Aims and objectives: This study evaluated the accuracy of subtyping specimens obtained with small biopsy forceps. Methods: We reviewed the pathology reports of 144 patients in our three previous studies who were diagnosed with NSCLC by bronchoscopy and underwent surgical resection at Nagoya Medical Center to evaluate the usefulness of thin/ultrathin bronchoscopy with a 1.5 mm biopsy forceps. The concordance rates between the results for the bronchoscopic and surgical specimens were analyzed. “Suspicious” or “favoring” suptypes were categorized as positive in the analysis. Results: The final pathological diagnoses from surgical specimens were adenocarcinoma in 102 cases, squamous cell carcinoma in 38, adenosquamous carcinoma in 2, and large cell carcinoma and sarcomatoid carcinoma in 1 case each. The concordance rate between bronchoscopic and surgical specimen results was 89% (128 of 144); 83% (58 of 70) in the two studies conducted before 2009 and 95% (70 of 74) in the most recent study (p = 0.03). Immunohistochemistry was performed in 25% (36 of 144) of the bronchoscopy specimens. Conclusion: The pathological subtypes of NSCLC classified with thin/ultrathin bronchoscopy specimens obtained using small biopsy forceps correlated with those based on surgical specimens, especially in the most recent series.