Distinguishing Adenocarcinoma from Squamous Cell Carcinoma in the Lung Using Double Stains: Napsin A and p63 and TTF-1 and CD141
D Tacha, D Zhou, RL Henshall-Powell. Biocare Medical, Concord
Background: To distinguish primary lung tumors from metastatic tumors to the lung, a panel of antibodies is used. The current FDA-approved standard treatment for non-small cell lung cancer is Carboplastin/Taxol/Avastin. However, based upon survival benefit; patients with squamous cell carcinoma (SCC) should not receive Avastin due to a 30% mortality rate by fatal hemoptysis. The use of TTF1, CK7 and p63 has been used to differentiate primary lung cancer from metastases. Thrombomodulin (CD141) has been shown to be sensitive for SSC and Napsin A has been shown to be a specific marker of lung adenocarcinoma (LADC); however, information on specificity of Napsin A from other cancer sites is desirable. We investigated the specificity and sensitivity of Napsin A on a wide spectrum of normal and neoplastic tissues including lung cancers and double stain protocols with Napsin A, CD141, TTF1 and p63 were developed.
Design: Tissue microarrays (TMA) were constructed from archival normal and neoplastic tissues. TMAs were deparaffinized in the usual manner and antigen retrieval was performed. Napsin A was evaluated for specificity and sensitivity. Lung cancer TMAs were evaluated with double-stain procedures for TTF1, CD141, p63 and Napsin A.
Results: Napsin A was positive in 50% of renal cell carcinomas; 21% of thyroid cancers; 2% of ovarian cancers; 0% of cervical cancer (squamous cell) and 16% of cervical adenocarcinomas. Breast, colon, prostate, bladder, seminoma, liver, lymphoma, leiomyosarcoma and pancreatic cancers were all negative. In normal tissues, only lung and kidney were positive. In LADC, Napsin A demonstrated equal sensitivity to TTF1 (77.4%) but was slightly more specific (Table 1). Napsin A was negative in 93.4% of SSC, while CD141 and p63 were positive (89.8% & 75%) in SCC respectively. There were 2 cases of SCC that did not express p63 or CD141, but expressed Napsin A and TTF1.
|TTF1 + Napsin A||31||26|
|p63 + CD141||49||44|
|Adenosquamous Cell Carcinoma||p63||7||4|