Lung Squamous Cell Carcinoma With Anaplastic Lymphoma Kinase Rearrangement and TP53 Co-mutation Treated Successfully with Ensartinib: A Case Report

Background: Detection of anaplastic lymphoma kinase (ALK) gene rearrangements is an important step in the selection of effective therapies for patients with advanced lung adenocarcinoma. However, there have been few reports of ALK‐positive lung squamous cell carcinoma (LSCC) and, even more rarely, LSCC with ALK rearrangement and TP53 co-mutation. Thus, it remains unclear whether ALK and TP53 co-mutant LSCC responds to ALK inhibitor treatment. Ensartinib is a novel ALK tyrosine kinase inhibitor (TKI). Case presentation: A 73-year-old female nonsmoker was diagnosed with advanced squamous cell carcinoma of the right lung (grade 3, cT4N3M1c, stage IVB). Targeted next-generation sequencing indicated that the cancer cells harbored both the EML4-ALK variant 1 rearrangement (E13;A20) and TP53 exon10 p.L348S (c.1043T>C) mutation, accounted for 70.04%. After only one cycle of ensartinib therapy, the patient exhibited a good partial response in most target lesions, and her performance status improved from 4 to 2. Conclusions: This result strongly suggests that ensartinib, a novel second-generation ALK inhibitor, may be an effective and rapid treatment for patients with this rare subtype of squamous cell carcinoma. Routine molecular analysis of ALK status in patients with LSCC is recommended. Results of the present study may provide some insight into treatment strategies for patients with ALK- and TP53-positive LSCC.