Detection of tumor spread through airspaces by airway secretion cytology from resected lung cancer specimens

• Published in: Pathology international Vol. 67; no. 10; pp. 487 - 494
• Main Authors: Isaka, Tetsuya, Yokose, Tomoyuki, Miyagi, Yohei, Washimi, Kota, Nishii, Teppei, Ito, Hiroyuki, Nakayama, Haruhiko, Yamada, Kouzo, Masuda, Munetaka
• Format: Journal Article
• Language: English
• Published: Australia Wiley Subscription Services, Inc 01-10-2017
• Subjects: Adenocarcinoma; Adult; Aged; Aged, 80 and over; Bodily Secretions - cytology; Bronchus; Carcinoma, Non-Small-Cell Lung - pathology; Cellular biology; Clusters; Cytology; EGFR; Epidermal growth factor receptors; exon 19 deletion mutation; exon 21 L858R mutation; Female; Glycoproteins; Humans; Invasiveness; Lung cancer; Lung Neoplasms - pathology; Male; micropapillary; Middle Aged; Neoplasm Invasiveness - pathology; Patients; Respiratory tract; Secretions; Squamous cell carcinoma; STAS; Surgery; Tumors; lung cancer; cytology; STAS; micropapillary; adenocarcinoma; exon 19 deletion mutation; EGFR; exon 21 L858R mutation
• ISSN: 1320-5463; 1440-1827
• DOI: 10.1111/pin.12570

It currently remains unclear whether tumor spread through airspaces (STAS) actually exist in vivo or are an artifact. The morphologies of STAS and tumor cell clusters in airway secretions collected from the segmental or lobar bronchus of resected lung adenocarcinomas and squamous cell carcinomas were compared among 48 patients. The EGFR status of tumor cell clusters in airway secretions was also compared with that of the main tumor in EGFR mutant adenocarcinomas. Tumor cell clusters were observed in the airway secretion cytology of ten patients (20.8%), and eight patients were adenocarcinoma (20.0% of adenocarcinoma). The morphology of STAS closely resembled that of tumor cell clusters detected in airway secretion cytology. The positive rates of airway secretion cytology were 83.3%, 100%, and 50% in papillary adenocarcinoma, micropapillary adenocarcinoma, and invasive mucinous adenocarcinoma, respectively. Among three EGFR mutant adenocarcinomas, the EGFR mutation subtypes of the main tumors in FFPE sections and tumor cell clusters in airway secretions were identical. These indicate that STAS may be detected in the airway secretion cytology. STAS is common in papillary or micropapillary adenocarcinoma and may spread as far as the segmental or lobar bronchus at the time of surgery.