Application of metagenomic next-generation sequencing in the diagnosis of pneumonia in patients with cancer

Background With the development of new sequencing technologies, metagenomic next-generation sequencing (mNGS) has become a diagnostic tool for respiratory tract infections. Patients with cancer may develop pneumonia caused by infections or antitumor therapy. Therefore, pneumonia in patients with cancer is more complex than that in healthy individuals. Currently, few reports are available on the use of mNGS for diagnosing pneumonia in patients with cancer. Methods In this retrospective study, 14 patients with cancer diagnosed with pneumonia in March 2023 were enrolled from the Emergency Department of the Chinese Academy of Medical Sciences Cancer Hospital. Sputum samples from the patients were examined using conventional tests and mNGS to identify pathogens. The mNGS and conventional test results were compared to assess the diagnostic yield and value of mNGS in improving the prognosis of pneumonia in patients with cancer. Results mNGS was more sensitive than conventional tests (sputum culture [SC] and polymerase chain reaction [PCR]) for detecting pathogens. The results were positive in 12/14 samples (86%) using mNGS compared with 8/14 samples (57%) using conventional testing. Compared with conventional tests, mNGS detected additional pathogens in 8 specimens. In 9/14 samples (64%), mNGS detected more pathogens than conventional testing. In nine patients (64%), the diagnosis was changed, and the antimicrobial regimen was adjusted based on the mNGS results. mNGS detected antibiotic resistance genes in five patients, which provided guidance for antibiotic selection. Conclusions mNGS is a promising technology for detecting pneumonia pathogens in patients with cancer and improves the diagnostic yield and prognosis. mNGS can be used to aid in early diagnosis and guide treatment of pneumonia in patients with cancer.