Background New developments in the treatment of primary lung cancer have necessitated further pathologic subclassification of nonsmall cell lung carcinomas (NSCLC). Certain therapeutic agents should not be used in squamous cell carcinoma or neoplasms with a dominant squamous component. The aim of this study was to identify the value of immunohistochemical markers p63, thyroid transcription factor-1, and napsin A (novel aspartic proteinase of the pepsin family) in the classification of NSCLC into squamous and nonsquamous subtypes. Thirty cases proved to be NSCLC were selected for this study.
ResultsOut of 14 squamous cell carcinomas, 12 (85.7%) reacted with p63, whereas only one (7.1%) reacted with thyroid transcription factor (TTF)-1, showing a weak focal staining pattern, and none with napsin A. Out of the 12 adenocarcinomas, eight (66.7%) cases stained for TTF-1, 10 (83.3%) for napsin A, and only one (8.3%) for p63. Out of the four large cell carcinomas, only two (50%) cases reacted with TTF-1, and none with napsin A and p63.Comparing the two markers of lung adenocarcinoma, napsin A showed a higher sensitivity (83.3%) and specificity (100%) than TTF-1 (66.7 and 83.3% respectively).
ConclusionThe current results indicate that the use of p63, TTF-1, and napsin A markers may be useful to subclassify NSCLC and to improve therapeutic selection of patients with lung cancer. Egypt J Pathol 31:62-67 c
Background: Triple negative breast cancer (TNBC) lacks the benefit of a specific target therapy, so identification and evaluation of new therapeutic agents is a high priority. Enhancer of zeste homolog 2 (EZH2) is a putative stem cell marker involved in cell cycle regulation and was linked to aggressive breast cancer. Cytokeratin 5/6 (CK5/6) is a basal cytokeratin used to define basal like breast cancer. The aim: The aim of this work is to investigate the expression of enhancer of EZH2 and CK5/6 in triple negative in comparison with non-triple negative breast cancer using immunohistochemistry. Methods: EZH2 and CK5/6 were retrospectively analyzed by immunohistochemistry in 44 paraffin-embedded specimens of breast cancer patients (20 cases of triple negative and 24 of non-triple negative breast cancer). Results: TNBC was significantly associated with higher grade (p=0.001), high tumor budding (p=0.029), syncytial growth pattern (p=0.002), lymphovascular invasion (p=.0012), geographic necrosis (p=0.003) and lymphocytic infiltrate (p=.001). EZH2 expression is significantly associated with TNBC in comparison with non-TNBC (P=0.001). CK5/6 expression was observed in 75% of cases of TNBC in comparison to 30% of non-TNBC with a statistically significant relation between CK5/6 expression and TNBC (P=0.004). Among cases of TNBC, CK5/6 expression was significantly associated with lymph node metastasis and high tumor budding. Conclusion: Triple negative breast cancer has distinctive but not pathognomonic morphological features. EZH2 was highly expressed in TNBC in comparison with non-TNBC and this may explain the aggressiveness of triple negative breast cancer. Basal breast cancer, identified by CK5/6 expression, showed characteristic features in the form of high tumor budding, marked lymphocytic infiltrate and higher incidence of lymph node metastasis. This finding indicates that CK5/6 positive expression in TNBC is associated with poor prognostic characteristics.
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