- The International Association for the Study of Lung Cancer has issued a consensus document on immunohistochemistry (IHC) in lung cancer, including guidance based on questions frequently encountered in daily practice.
Why this matters
- The document includes newly published clinical data and information from experts in thoracic pathology to help clinicians navigate the use of IHC, an important element in the lung cancer diagnostic process.
Key issues addressed
- The best combination of markers to use in daily practice.
- The extent of TTF1- and p40-positive reactions that should be considered positive.
- Staining differences in lung adenocarcinoma between TTF1 clones SPT24, SP141, and 8G7G3/1.
- Diagnosis of non-small cell carcinoma (NSCC) that is diffusely positive for CK7 but negative for TTF1 and p40.
- Applying NE markers to NSCC.
- Antibody panels to differentiate neuroendocrine tumors from other types of NSCC.
- Using proliferation marker in diagnosis.
- Using IHC to diagnose uncommon lung cancer subtypes, such as sarcomatoid carcinoma, salivary gland-type tumors, and nuclear protein in testis carcinoma.
- Cytology preparations for immunostaining.
- Recommended IHC panels to differentiate lung mucinous adenocarcinoma from metastatic mimics.
- IHC or other markers to differentiate primary lung cancers from metastases.