A clue to ‘previewing’ complete remission in lung cancer, once knowable only after surgery [Health Check]

[Financial News] Until now, whether preoperative immunotherapy had completely eliminated the cancer cells could be determined only after surgery, by removing tissue for examination. Researchers have now raised the possibility of predicting this before surgery through imaging tests and immune-cell analysis.
A joint research team comprising Professors Lee Seung-ryong and Choi Ju-hwan of the Department of Pulmonary and Allergy Medicine at Korea University Guro Hospital, Professor Lee Eun-seong of its Department of Nuclear Medicine, resident Lee Seung-hoon of its Department of Internal Medicine, and Professors P. Rod Dunbar and Park Saemul of the Faculty of Biological Sciences at the University of Auckland in New Zealand analyzed PET/CT scans of lung cancer patients and immune cells in their tumor tissue, finding clues that could help gauge the likelihood of complete remission before surgery and patients’ response to treatment. The findings were published in the international journal Translational Lung Cancer Research.
Neoadjuvant immunotherapy, in which drugs are given before surgery to help the body’s immune cells attack cancer cells, is now widely used to treat lung cancer. However, responses vary from patient to patient, making it difficult to predict how effective treatment will be. As a result, calls are growing for indicators that can help assess treatment effectiveness and the likelihood of complete remission before surgery—a state in which no cancer cells are detected on examination.
The research team analyzed PET/CT results from before and after treatment, along with the characteristics of immune cells in tumor tissue obtained through pretreatment biopsies, in 13 patients with stage II–III non-small cell lung cancer who received neoadjuvant immunotherapy at Korea University Guro Hospital from December 2017 to November 2023. Eight patients were in the complete-remission group and five in the non-complete-remission group.
The results showed that the decrease in the tumor-to-liver ratio (TLR), which compares glucose uptake in tumor tissue with that in the liver on PET/CT scans, was associated with whether patients achieved complete remission. The ratio fell by 82% in the complete-remission group, compared with 58% in patients who still had cancer cells. This suggests that changes in PET/CT measurements could help assess the likelihood of complete remission before surgery.
Analysis of the tumor tissue also revealed features shared by patients who responded well to treatment. The complete-remission group had more CD4+ T cells, which help mount an immune response against cancer, as well as more T cells carrying TIGIT, a protein that suppresses immune-cell activity. This suggests that the characteristics of immune cells in tumor tissue before treatment could help identify patients likely to respond well to immunotherapy.
“The significance lies in our confirmation that preoperative imaging findings and the characteristics of immune cells in tumor tissue before treatment are associated with whether patients achieve a pathological complete remission,” said Professor Lee Seung-ryong. “If further research validates the usefulness of these indicators, they could help us assess each patient’s treatment response more accurately and develop appropriate treatment strategies.”
“Since the same immunotherapy can have different effects in different patients, it is important to predict treatment response,” said Professor Choi Ju-hwan. “We will further validate the immune-cell characteristics identified in this study and build an evidence base for using them in personalized treatment for each patient.” 

[email protected] Jung Myung-jin, medical correspondent Reporter