%0 Journal Article %T The clinicopathological features and possible physiological mechanisms of only the EGFR-T790M primary mutation in patients with lung adenocarcinoma. %A Zhao P %A Xu L %A Zhu H %A Ding W %A Tang H %J Pathol Res Pract %V 259 %N 0 %D 2024 Jul 17 %M 38781763 %F 3.309 %R 10.1016/j.prp.2024.155352 %X BACKGROUND: The treatment of non-small cell lung cancer (NSCLC) patients can be complicated by the presence of the EGFR-T790M mutation. Although primary or secondary EGFR-T790M mutations have been extensively studied worldwide, there are few reports on the clinicopathological characteristics and physiological mechanisms of lung adenocarcinoma (LUAD) with only the EGFR-T790M primary mutation.
METHODS: The clinical data of all LUAD patients with only the EGFR-T790M primary mutation were collected. Immunohistochemical staining was performed on cell cycle-related proteins, targeted therapy indicators, and prognosis-related proteins in the specimens obtained from puncture biopsies or surgeries.
OBJECTIVE: The aim of this study is to analyze the clinicopathological features and possible physiological mechanisms of only the EGFR-T790M primary mutation in LUAD, and to offer recommendations for clinical management.
RESULTS: Two patients who have only the T790M de novo mutation were both female (2/12,928, 0.02%). β-catenin and Cyclin D1 were both highly expressed. In case 1, IHC results showed a positive Ki67 and mutant P53 and there was a significant increase in serum CYFRA 21-1. Third-generation of EGFR TKIs resulted in a partial response (PR) time of less than 8 months in case 1. In case 2, the patient underwent surgical resection and adjuvant chemotherapy, resulting in a progression-free survival (PFS) time of 25 months.
CONCLUSIONS: The results suggest that abnormal activation of the Wnt signaling pathway may be specifically associated with the EGFR-T790M primary mutation in LUAD. Furthermore, it has been observed that patients with significant Ki67, mutant P53, and CYFRA 21-1 expression tend to have a poor prognosis.