[A Case of Interstitial Pneumonia Induced by Immune Checkpoint Inhibitors for Gastric Cancer During the COVID- 19...

The novel coronavirus disease(corona virus disease 2019: COVID-19)has calmed down worldwide, and the severity of the disease is decreasing. On the other hand, due to the emergence of strain mutations, the number of infected people shows a wavy course. I have experienced a case of gastric cancer that underwent chemotherapy including an immune checkpoint inhibitors(ICI) early after COVID-19, so I will report it including a discussion.

A 71-year-old man. The patient visited our hospital with a chief complaint of stomach discomfort, and gastrointestinal endoscopy revealed advanced gastric cancer accompanied by narrowing of the gastric lumen. The histopathological examination showed a poorly differentiated adenocarcinoma. A CT scan of the chest and abdomen showed thickening of the entire gastric wall, indicating the presence of enlarged adjacent lymph nodes and infiltration into adjacent organs. No other obvious distant metastases were observed. Staging laparoscopy was performed, it revealed infiltration of the posterior wall of the stomach into the celiac artery and anterior surface of the pancreas. We determined that curative resection would be difficult. As a result of planning chemotherapy for locally advanced gastric cancer, the patient contracted COVID-19 due to a hospital- acquired infection. The patient's COVID-19 infection was managed with supportive care alone without severe complications, and they recovered within the course of treatment. Two weeks after the onset of the infection, chemotherapy(FOLFOX+ Nivo)was initiated. The patient completed up to 9 courses of chemotherapy, and the treatment response was determined to be stable disease(SD). Due to a tendency of stenosis in the gastric lumen, the possibility of future dilation procedures was considered. As a result, the patient underwent second-line chemotherapy with a combination of wPTX+RAM. After completing 1 course of treatment, the patient developed drug-induced interstitial pneumonia, which was managed with intensive care and steroid pulse therapy, resulting in improvement. There was progression of gastric lumen stenosis, and an endoscopic dilation procedure/stent placement was performed. Subsequently, there was a rapid increase in malignant ascites and a decline in activities of daily living(ADL), leading to palliative care. Unfortunately, the patient succumbed to cancer-related complications 10 months after the diagnosis.

In this case, the serial antibody titers of COVID-19 also indicated the sustained effectiveness of the multi-drug combination chemotherapy. The treatment course suggests a suspicion of drug-induced interstitial pneumonia due to PTX/RAM, but the long-term imaging follow-up implies that ICI may be the cause. When using ICI, COVID-19 infection alone may pose a potential risk factor.