BACKGROUND: Appropriate treatment of nonsmall cell lung cancer (NSCLC) depended on histologic type. The aim of this study was to evaluate the expression levels of Napsin A, thyroid transcription factor-1 (TTF-1), and p63 by immunostaining using CytoRich Red preserved cytocentrifuged bronchial brushings. METHODS: The expression levels of Napsin A, TTF-1, and p63 were semiquantitatively evaluated using proportion and intensity scores in 12 patients from whom both bronchial brushing cytology and bronchial biopsy samples had been obtained, as well as in a selection of 64 resected NSCLC tissue samples, and 8 normal or benign bronchial brushing cytology samples. RESULTS: The nuclear expressions of TTF-1 and p63 allowed for good visualization of cancer cells, whereas the cytoplasmic expression of Napsin A in cancer cells was often more difficult to evaluate because medium-sized and large macrophages also expressed Napsin A. Napsin A and TTF-1 were reliable adenocarcinoma markers, and p63 was a reliable squamous cell carcinoma marker in cytology, and histology samples. The average scores of Napsin A, TTF-1, and p63 were highly correlated in bronchial brushing cytology and bronchial biopsy samples, whereas TTF-1 expression was significantly lower than Napsin A expression in resected NSCLC tissue samples (P < .001). CONCLUSIONS: Immunostaining of bronchial brushings fixed with CytoRich Red was useful in determining histologic types in NSCLC. It was suggested that the panels of Napsin A, TTF-1, and p63 were effective in identifying histologic type in NSCLC, and that a combination of either Napsin A and p63 or TTF-1 and p63 should be chosen, depending on morphology.
BACKGROUND: Appropriate treatment of nonsmall cell lung cancer (NSCLC) depended on histologic type. The aim of this study was to evaluate the expression levels of Napsin A, thyroid transcription factor-1 (TTF-1), and p63 by immunostaining using CytoRich Red preserved cytocentrifuged bronchial brushings. METHODS: The expression levels of Napsin A, TTF-1, and p63 were semiquantitatively evaluated using proportion and intensity scores in 12 patients from whom both bronchial brushing cytology and bronchial biopsy samples had been obtained, as well as in a selection of 64 resected NSCLC tissue samples, and 8 normal or benign bronchial brushing cytology samples. RESULTS: The nuclear expressions of TTF-1 and p63 allowed for good visualization of cancer cells, whereas the cytoplasmic expression of Napsin A in cancer cells was often more difficult to evaluate because medium-sized and large macrophages also expressed Napsin A. Napsin A and TTF-1 were reliable adenocarcinoma markers, and p63 was a reliable squamous cell carcinoma marker in cytology, and histology samples. The average scores of Napsin A, TTF-1, and p63 were highly correlated in bronchial brushing cytology and bronchial biopsy samples, whereas TTF-1 expression was significantly lower than Napsin A expression in resected NSCLC tissue samples (P < .001). CONCLUSIONS: Immunostaining of bronchial brushings fixed with CytoRich Red was useful in determining histologic types in NSCLC. It was suggested that the panels of Napsin A, TTF-1, and p63 were effective in identifying histologic type in NSCLC, and that a combination of either Napsin A and p63 or TTF-1 and p63 should be chosen, depending on morphology.