Expression of p40 immunohistochemistry in non-small cell lung carcinoma

• Main Authors: Ahmad Affandi, Khairunisa, Md Zin, Reena Rahayu, Chandramaya, Sabrina, Mustangin, Muaatamarulain
• Format: Article
• Language: English
• Published: College of Pathologists, Academy of Medicine Malaysia 2017
• Subjects: RB Pathology
• Online Access: http://irep.iium.edu.my/85947/1/abstracts%20iapmd%202017.pdf; http://irep.iium.edu.my/85947/; http://www.mjpath.org.my/2017/v39n3/abstracts.pdf
• Institution: Universiti Islam Antarabangsa Malaysia

Introduction: Lung cancer is the third most common cancers worldwide and in Malaysia. With the major advances in molecular testing of lung cancers and introduction of targeted therapies, the distinction between adenocarcinoma and squamous cell carcinoma (SCC) and its pathologic subtyping becomes important. Recent studies showed that p40 is highly specific for squamous and basal cells, and superior to p63 for the diagnosis of lung SCC. This study aimed to evaluate the use of p40 immunohistochemistry in diagnosis of non-small cell lung carcinoma and its potential to replace current p63 antibody as the best immunohistochemical squamous marker. Methods: Seventy formalin-fixed paraffin-embedded cases previously diagnosed primary lung SCC (n=35) and lung adenocarcinoma (n=35) from January 2008 to December 2016 were retrieved from Department of Pathology, Universiti Kebangsaan Malaysia. We compared the results of tumour cells immunoreactivity for p40 and p63 antibodies in lung SCC and lung adenocarcinoma. Results: The p40 was positive in 29 cases of previously diagnosed lung SCC (82.8%) and two cases of lung adenocarcinoma (5.7%). The p63 was positive in 31 lung SCC (88.6%) and 22 of lung adenocarcinoma (62.9%). The reactivity for both p40 and p63 in lung SCC was strong and diffuse whereas the reactivity of both antibodies in lung adenocarcinoma is variable. Conclusions: We found that the expression of p40 is equivalent to p63 in lung SCC, but p40 is an excellent marker in distinguishing lung SCC from adenocarcinoma. We suggest that p40 is considered for routine use and replace p63 as lung SCC marker.