Case Report: Prompt Response to Savolitinib in a Case of Advanced Gastric Cancer With Bone Marrow Invasion and MET Abnormalities

Abstract

Gastric cancer is one of the most common malignant tumors and patients show a short survival, those combined with bone marrow invasion have a median survival of only 37 days. Here we reported the treatment of a 47-year-old male with advanced gastric cancer and complicated with bone marrow invasion and extensive metastases, who did not tolerate chemotherapy, under monotherapy with savolitinib, a MET receptor tyrosine kinase inhibitor. Before treatment, the patient was in severe pain and presented with thrombocytopenia and hemorrhagic anemia. Savolitinib was given based on amplification and rearrangement of the MET gene in his tumor. After savolitinib treatment, the patient's condition promptly improved, efficacy evaluation indicated partial remission, and the patient was alive and remained progression-free at 15 weeks at the time of reporting. No obvious adverse reactions occurred. Besides, another case of a female gastric cancer patient with MET amplification who received savolitinib monotherapy as a third-line treatment that remained progression-free at 12 weeks was also reported. This report provides a new reference for understanding MET abnormalities in gastric cancer and offers a possibility for future application of MET tyrosine kinase inhibitors in the therapy of gastric cancer with MET abnormalities. Also, it suggests that sequencing of MET can be considered a routine target in advanced gastric cancer patients.

Keywords: MET gene; advanced gastric cancer; bone marrow invasion; case report; savolitinib.

Figure 1

Before treatment, enhanced CT showed (A) thickening of gastric wall and (B) multiple enlarged abdominal lymph nodes, as well as mixed bone metastasis of the vertebras; the red arrow represents the location of the lesion; (C) Gastroscopy showed the lesion was found in the greater curvature of upper gastric body, about 5 cm × 8 cm in size, with uneven surface and bloody substances; and Hematoxylin-eosin staining of (D) the gastric biopsy, (E) the bone marrow smear, and (F) the bone marrow biopsy.

Figure 2

(A) The copy number ratio of MET to centromere of chromosome 7 in tissues, each red point represents an exon of MET; (B) MET-ST7 fusion diagram.

Figure 3

Variation trends of (A) platelet and (B) hemoglobin since admission, the lower downward arrow represents the date of platelet and hemoglobin transfusion, respectively. After savolitinib treatment, enhanced CT showed that (C) the thickness of gastric wall was thinner and (D) the abdominal lymph nodes were shrunk and fewer, the red arrow represents the location of the lesion; and post-treatment Hematoxylin-eosin staining of (E) the bone marrow smear and (F) the bone marrow biopsy.