[1808] TTF-1, Napsin A, p63, TRIM29, Desmoglein-3 and CK5: An Evaluation of Sensitivity and Specificity and Correlation of Tumor Grade for Lung Squamous Cell Carcinoma vs. Lung Adenocarcinoma.

David Tacha, Charlie Yu, Thomas Haas. Biocare Medical, LLC, Concord, CA; Mercy Health System, Janesville, WI

Background: The current FDA-approved standard treatment for non-small cell lung cancer is Carboplatin/Taxol/Avastin; however, patients with lung squamous cell carcinoma (SqCC) should not receive Avastin due to a 30% mortality rate by fatal hemoptysis. Antibodies TTF-1 and p63 have been used to differentiate primary lung cancers; however, the need for a more sensitive and specific panel of antibodies to differentiate lung adenocarcinoma (LADC) from lung SqCC is of the utmost importance. In a pilot study, 14 antibodies were evaluated using an IHC method. Based on sensitivity and specificity, a six antibody panel was selected and tested on 132 lung cancer cases. Correlation of this antibody panel with tumor grade was determined.
Design: Formalin-fixed paraffin-embedded TMA tissues for lung cancers were obtained and processed in the usual manner for IHC analysis. The 6 antibody panel was applied to 65 cases of lung SqCC and 67 cases of LADC. Antibodies were optimized with a polymer detection system and visualized with DAB and/or Fast Red.
Results: A six antibody panel was evaluated for sensitivity and specificity (Table 1). Napsin A and TTF-1 provided 91% sensitivity (61/67) and 100% specificity for LADC. The combination of Desmoglein-3, CK5, p63 and TRIM29 provided 93.8% (61/65) sensitivity and 100% specificity for lung SqCC. In all cases, 8.3% (11/132) were unclassified and 7.6% (10/132) were reclassified by the IHC six antibody panel. 5.6% (5/89) of tumors grades 1-2 and 14% (6/43) of grade 3 cases were unclassified by IHC.

	TTF-1	Napsin A	p63	TRIM29	DSG-3	CK5
SqCC	4/65 (6%)	0/65 (0%)	61/65 (94%)	61/65 (94%)	54/65 (83%)	55/65 (85%)
LADC	51/67 (76%)	60/67 (90%)	11/67 (16%)	8/67 (12%)	0/67 (0%)	0/67 (0%)

Conclusions: Desmoglein-3, CK5 and Napsin A are highly sensitive and very specific markers for lung cancer and should be used in the initial screening of squamous vs. adenocarcinoma differentiation. TRIM29 and p63 positive staining in conjunction with TTF-1 and Napsin A negative staining were useful in certain cases of SqCC differentiation. Grade 3 lung cancers appears to be the more difficult to classify, therefore a more extensive panel, such as that described in this study should be considered.
Category: Pulmonary

Tuesday, March 1, 2011 9:30 AM

Poster Session III # 268, Tuesday Morning