Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, Hong Kong.
Division of Cardiothoracic Surgery, Department of Surgery, Prince of Wales Hospital, Hong Kong.
Pathology. 2020 Apr;52(3):323-328. doi: 10.1016/j.pathol.2019.12.003. Epub 2020 Feb 27.
Whether EGFR mutation occurs in lung squamous cell carcinoma (SCC) remains a controversial issue. Although numerous trials have shown positive response to tyrosine kinase inhibitors in SCC, these observations have not been well correlated with presence or absence of EGFR mutation. A complicating issue is that adenosquamous carcinoma, a mimic of SCC, frequently harbours EGFR mutations. We evaluated the EGFR mutation status of 191 cases initially diagnosed as SCC of lung origin in years 2000-2011, and performed a panel of markers including p40, p63, CK5/6, TTF-1, mucicarmine on the tissue microarray or tissue blocks from each case, to ascertain the squamous differentiation of each case. Four cases were found to have EGFR mutations, with three showing typical squamous morphological features and immunohistochemical profile on all available tumour blocks, and one reclassified as adenosquamous carcinoma. Mixed responses were noted for two of the patients with EGFR-mutated SCC treated with tyrosine kinase inhibitors. In conclusion, we report that a small subset of rigorously proven SCC harbours EGFR mutation. It also appears in our cohort that EGFR-mutated tumours, in the context of SCC, may have relatively poor response to tyrosine kinase inhibitors.
在肺鳞癌（SCC）中是否发生 EGFR 突变仍然存在争议。尽管许多试验表明 SCC 对酪氨酸激酶抑制剂有阳性反应，但这些观察结果与 EGFR 突变的存在与否并没有很好地相关。一个复杂的问题是，腺鳞癌是 SCC 的模拟物，经常存在 EGFR 突变。我们评估了 191 例在 2000 年至 2011 年间最初诊断为肺 SCC 的病例的 EGFR 突变状态，并对每个病例的组织微阵列或组织块进行了包括 p40、p63、CK5/6、TTF-1、粘卡红在内的标志物进行了 panel 检测，以确定每个病例的鳞状分化。发现 4 例存在 EGFR 突变，其中 3 例在所有可用肿瘤块上显示出典型的鳞状形态特征和免疫组织化学特征，1 例重新分类为腺鳞癌。用酪氨酸激酶抑制剂治疗的 2 例 EGFR 突变 SCC 患者出现混合反应。总之，我们报告说，一小部分经过严格证实的 SCC 存在 EGFR 突变。在我们的队列中，似乎在 SCC 背景下，EGFR 突变的肿瘤对酪氨酸激酶抑制剂的反应相对较差。
