Supplementary Material for: Multiplex intraoperative rapid immunohistochemistry with non-contact antibody mixing for distinguishing the histologic phenotype of lung cancer

Introduction: Determining a surgical strategy for early-stage lung cancer requires an accurate histologic diagnosis. Immunohistochemistry (IHC) enables reliable diagnosis of histological types but requires more time and more tumor tissue slides than hematoxylin and eosin staining. We aimed to assess the clinical validity of a new rapid multiplex IHC technique utilizing alternating current (AC) mixing for intraoperative lung cancer diagnosis.
Methods: Forty-three patients who underwent radical resection of lung cancers were enrolled in a retrospective observational study. Frozen sections were prepared from lung tumor samples, and rapid IHC employing AC mixing was implemented alongside a multiplex IHC protocol targeting thyroid transcription factor-1 + Cytokeratin 5, Desmoglein 3 + Napsin A, and p63 + tripartite motif containing 29. We then evaluated the concordance between intraoperative diagnoses derived from rapid multiplex IHC and final pathology.
Results: The concordance rate between the pathological diagnosis made with added rapid multiplex IHC and the final pathology was 93.0% (Cohen's 𝜅 coefficient = 0.860 and 95% CI 0.727–0.993). When considering only adenocarcinoma and squamous cell carcinoma, the diagnoses were in agreement for all cases.
Conclusions: We suggest rapid multiplex IHC as a promising tool for determining surgical strategies for lung tumors.