A retrospective study of tislelizumab combined with chemotherapy for downstaging and conversion therapy in patients with locally advanced lung cancer

Objective: This study aimed to evaluate the efficacy and safety of tislelizumab combined with chemotherapy in patients with locally advanced lung cancer through the retrospective collection of real-world data. Methods: This study was a single-arm, multicenter, retrospective, real-world study. The study mainly includes patients with locally advanced lung cancer who are expected to be unable to undergo radical resection or whose surgical procedures were deemed more complex. All participants received at least two cycles of tislelizumab in combination with chemotherapy between October 1, 2020, and November 30, 2021.Statistically analyze the baseline characteristics of patients, the rate of R0 surgical resection, the major pathological response rate, and the occurrence of adverse events. Additionally, evaluate the efficacy and safety of tislelizumab combined with chemotherapy for downstaging and conversion therapy in patients with locally advanced lung cancer. Results: A total of 65 patients were enrolled, with a median age of 62.0 (57.0-66.0) years, including 62 (95.4%) males and 3 (4.6%) females. Pathological diagnosis of squamous cell carcinoma (78.5%), adenocarcinoma (18.5%), squamous cell carcinoma with neuroendocrine differentiation, and malignant epithelial lung cancer accounted for 78.5%, 18.5%, 1.5%, and 1.5% respectively. The clinical stages of the patients were as follows: 26 (40.0%) cases were in stage IIIA, 33 (50.8%) as stage IIIB, and 6 (9.2%) as stage IIIC. Additionally, 30 (46.2%) had an ECOG PS score of 0. Furthermore, 38 (58.5%) had a history of smoking. Lastly, 25 patients (38.5%) had a past medical history. The median treatment cycles in the regimen was 3. The primary adverse events related to treatment included lymphocyte count decreased (47.7%), alanine aminotransferase increased (27.7%), aspartate aminotransferase increased (26.2%), anemia (21.5%), neutrophilia granulocyte count decreased (21.5%), hypoalbuminemia (21.5%), white blood cell count decreased (20.0%), and lactate dehydrogenase increased (15.4%). A total of 55 out of 65 patients were enrolled and underwent surgery. The surgery rate was 84.6% (95% CI: 73.5%-92.4%). All patients who underwent surgery achieved R0 resection after surgery, the R0 resection rate was 100.0% (95% CI: 93.5%-100.0%), and the median surgical interval was 5.7 weeks. Among these patients, 26 achieved a pathological complete response after surgery, and the pCR rate was 47.3% (95% CI: 33.7%-61.2%). Additionally, 42 patients achieved a major pathological response after surgery, resulting in an MPR rate of 76.4% (95% CI: 63.0%-86.8%). Conclusion: Tislelizumab combined with chemotherapy, demonstrates significant anti-tumor activity in patients with locally advanced lung cancer. This combination can reduce tumor volume, enhance the surgical resection rate, achieve a high pathological complete response rate, and is generally well tolerated. Immunotherapy combined with chemotherapy represents a promising new approach for downstaging and conversion therapy in patients with locally advanced lung cancer. It offers surgical opportunities for patients who have no chance of surgery or who have difficulty in surgery, and can increase the likelihood of achieving radical surgical resection.