title: Roles of immunohistochemical staining in diagnosing pulmonary squamous cell carcinoma.
abstract: BACKGROUND
  Differentiating morphologic features based on hematoxylin-eosin (HE) staining is the most common method to classify pathological subtypes of non-small-cell lung cancer (NSCLC). However, its accuracy and inter-observer reproducibility in pathological diagnosis of poorly differentiated NSCLC remained to be improved.
  
  
  METHODS
  We attempted to explore the role of immunohistochemistry (IHC) staining in diagnosing pulmonary squamous cell carcinoma (SQCC) with poorly differentiated features by HE staining or with elevated serum adenocarcinoma-specific tumor markers (AD-TMs). We also compared the difference of epidermal growth factor receptor (EGFR) mutation rate between patients with confirmed SQCC and those with revised pathological subtype. Logistic regression analyses were used to test the association between different factors and diagnostic accuracy.
  
  
  RESULTS
  A total of 132 patients who met the eligible criteria and had adequate specimens for IHC confirmation were included. Pathological revised cases in poor differentiated subgroup, biopsy samples and high-level AD-TMs cases were more than those with high/moderate differentiation, surgical specimens and normal-level AD-TMs. Moreover, biopsy sample was a significant factor decreasing diagnostic accuracy of pathological subtype (OR, 4.037; 95% CI 1.446-11.267, p=0.008). Additionally, EGFR mutation rate was higher in patients with pathological diagnostic changes than those with confirmed SQCC (16.7% vs 4.4%, p=0.157).
  
  
  CONCLUSIONS
  Diagnosis based on HE staining only might cause pathological misinterpretation in NSCLC patients with poor differentiation or high-level AD-TMs, especially those with biopsy samples. HE staining and IHC should be combined as pathological diagnostic standard. The occurrence of EGFR mutations in pulmonary SQCC might be overestimated.
authors: Sun Yat-sen University Cancer Center; State Key Laboratory of Oncology in South China; Collaborative Innovation Center for Cancer Medicine, Guangzhou, ChinaE-mail : zhangli6@mail.sysu.edu.cn.
authors: Yue
authors: Y
authors: Yan
authors: Ya-Xiong
authors: YX
authors: Zhang
authors: Wen-Feng
authors: WF
authors: Fang
authors: Shi-Yang
authors: SY
authors: Kang
authors: Jian-Hua
authors: JH
authors: Zhan
authors: Nan
authors: N
authors: Chen
authors: Shao-Dong
authors: SD
authors: Hong
authors: Wen-Hua
authors: WH
authors: Liang
authors: Yan-Na
authors: YN
authors: Tang
authors: Da-Cheng
authors: DC
authors: He
authors: Xuan
authors: X
authors: Wu
authors: Li
authors: L
authors: Zhang
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D018196:Carcinoma, Adenosquamous / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation; D015331:Cohort Studies; D066246:ErbB Receptors / Q000235:genetics; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007124:Immunoenzyme Techniques; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D011379:Prognosis
chemical_list: D014408:Biomarkers, Tumor; C512478:EGFR protein, human; D066246:ErbB Receptors