The impact of immunohistochemistry on the classification of lung tumors

ABSTRACT

Introduction: To highlight the role of immunohistochemistry to lung cancer classification on the basis of existing guidelines and future perspectives.

Areas covered: Four orienting key-issues were structured according to an extensive review on the English literature: a) cancer subtyping; b) best biomarkers and rules to follow; c) negative and positive profiling; d) suggestions towards an evidence-based proposal for lung cancer subtyping. A sparing material approach based on a limited number of specific markers is highly desirable. It includes p40 for squamous cell carcinoma (‘no p40, no squamous’), TTF1 for adenocarcinoma, synaptophysin for neuroendocrine tumors and vimentin for sarcomatoid carcinoma. A close relationship between genotype and phenotype also supports a diagnostic role for negative profiles.

Expert commentary: Highly specific and sensitive IHC markers according to positive and negative diagnostic algorithms seem appropriate for individual patients’ lung cancer subtyping.

KEYWORDS:

• Immunohistochemistry
• TTF1
• p40
• carcinoma
• diagnosis
• lung
• classification
• non-small cell lung cancer
• small cell lung cancer
• morphology
• algorithm

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Dedication

This work is dedicated with special mention to the memory of Carlotta, an extraordinarily lively girl who ultimately died of cancer in the prime of life.

Additional information

Funding

This work was supported by Novartis Farma S.p.A, Largo Umberto Boccioni 1, 21040-Origgio, Varese, Italy. The Funder had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript, which are responsibilities of the Authors only.