Ming Bai,1,* Wei-Xue Wang,1,2,* Ting Deng,1 Jing-Jing Duan,1 Yi Ba1,3 

1Department of Gastrointestinal Medical Oncology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Tianjin’s Clinical Research Center for Cancer, Tianjin Key Laboratory of Digestive Cancer, Tianjin, 300060, People’s Republic of China; 2Aerospace Center Hospital, Beijing, 100049, People’s Republic of China; 3Peking Union Medical College Hospital, Beijing, 100730, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Yi Ba, Department of Gastrointestinal Medical Oncology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Tianjin’s Clinical Research Center for Cancer, Tianjin Key Laboratory of Digestive Cancer, Tianjin, 300060, People’s Republic of China, Tel +86 22-23340123, Email bayi@tjmuch.com

Objective: This study aimed to identify the effectiveness and safety of PD-1 blockades among elderly patients with metastatic esophageal squamous cell carcinoma (ESCC) clinically.
Methods: A total of 78 elderly patients with previously treated metastatic ESCC aged ≥ 65 years who received PD-1 blockades monotherapy were included retrospectively. Demographic characteristics, therapeutic effectiveness and adverse reactions of the elderly patients who underwent PD-1 blockade therapy were recorded. Regular follow-up was conducted for all patients. The analysis aimed to identify potential risk factors for OS by examining the correlation between prognosis and subgroups based on baseline characteristics.
Results: The median age of the 78 elderly patients was 73 years, ranging from 65 to 87 years. Among the 78 patients, 18 cases showed partial response, 26 cases had stable disease, 29 cases experienced progressive disease and 5 cases were not assessable for response, yielding an ORR of 23.1%, a DCR of 56.4%. The prognostic outcomes indicated that among the 78 patients with metastatic ESCC who received PD-1 blockades, the median PFS was 3.1 months [95% confidence interval (CI): 1.64– 4.56], and the median OS was 10.9 months (95% CI: 6.02– 15.78), 24-month OS rate was 22.7% (95% CI: 12.8– 34.2%). In terms of the safety profile, among the 78 patients with metastatic ESCC during PD-1 blockades single-agent treatment, a total of 61 patients (78.2%) experienced any grade adverse reactions and the incidence of grade ≥ 3 adverse reactions were 20.5%. Briefly, the common adverse reactions manifested as fatigue (32.1%), gastrointestinal reaction (24.4%), diarrhea (19.2%), anemia (17.9%) and rash (16.7%). Overall tolerability of PD-1 blockade monotherapy in elderly patients with metastatic ESCC was acceptable and manageable.
Conclusion: PD-1 blockades single agent demonstrated encouraging effectiveness and acceptable safety profile for elderly patients with previously treated metastatic ESCC in clinical practice. Prospective study should be performed to elucidate the conclusion in this study subsequently.

Keywords: elderly patients, esophageal squamous cell carcinoma, PD-1 blockades, effectiveness, safety