A 91-year-old male was admitted to the Department of Respiratory and Critical Care Medicine, Ruijin Hospital in October 2020 because of an incidental finding of a lung mass for 20 days, increased carcinoembryonic antigen (CEA) levels, and localized emphysema in a local hospital (Figure 1). The patient first consulted at the local hospital because of cough, shortness of breath, anorexia, fever, chest pain, and other respiratory symptoms with unknown causes for more than 3 months. For further diagnosis, the patient was admitted to our hospital. He denied a smoking and drinking history, but both parents died of lung cancer. The patient had coronary heart disease (taking aspirin), hypertension (taking candesartan cilexetil), lacunar cerebral infarction, colon polyps (tubular adenoma with low-grade intraepithelial neoplasia revealed by colonoscopic polypectomy), and a history of tuberculosis 60 years ago.
Positron emission tomography (PET):MRI of the chest revealed a highly metabolic mass in the upper right lobe, a highly metabolic nodule at the apex of the right lung, and small nodules in the upper right lobe with traction of the adjacent pleura, with a slightly increased metabolism (Figure 2). Furthermore, adenocarcinoma cells were found by right upper lobe lesion biopsy. After subsequent evaluation, he was diagnosed with stage T3N2M0 adenocarcinoma of the right lung.
Amplification-refractory mutation system (ARMS)-polymerase chain reaction (PCR)-based single gene tests for EGFR, ALK, ROS1, BRAF, NRAS, KRAS, ERBB2, PIK3CA, and MET exon 14 skipping were all negative in the tissue biopsy. Then, rare mutations were tested by next-generation sequencing (NGS) for tissue biopsy (F1CDX; Foundation Medicine, Massachusetts, United States) and liquid biopsy (America Geneseeq Prime, Nanjing, China). An MET Y1003S mutation was detected in the tissue (Figure 3) but not in the liquid biopsy. There were no EGFR mutations, MET amplifications, or ALK/ROS1 fusion events in both testing. The patient started crizotinib 250 mg b.i.d. on December 20, 2020. Chest CT scan on January 11, 2021 showed a partial response and significant improvement of the lung lesions (right upper lung: from 55 x 43 mm to 23 x 17 mm, Figure 4).
After 1 month of crizotinib treatment, the patient was admitted because of chest distress, which could be alleviated by rest. Pulmonary artery thin layer CTA revealed pulmonary embolism in the left lower lobe. He was treated with low-molecular-weight heparin subcutaneous injection 0.4 ml q 12 h for 3 days and q.d. for 4 days, and then rivaroxaban 10 mg/day. His symptoms were alleviated after the treatment. Drug-induced abnormal liver function was considered because of the increased ALT and AST. The patient was given polyene phosphatidylcholine 228 mg two tablets t.i.d. On May 21, liver function was recovered. On July 30, 2021, the right upper lung lesion was 26 mm x 9 mm, which suggested a partial response.
Computed tomography (CT) scan of the primary lung lesion before and after crizotinib treatment. In November 2020, the tumor size was 55 x 43 mm.