Adjuvant nivolumab in resected oesophageal or gastroesophageal junction cancer following neoadjuvant chemoradiotherapy: Slovenian real-world data

BACKGROUND: Adjuvant nivolumab has become the new standard of care for patients with oesophageal and gastroesophageal junction cancer (OEC/GEJC) following neoadjuvant chemoradiotherapy (neoCRT) and surgical resection. In Slovenia, this treatment has been in use since January 2022. Here, we report the first Slovenian real-world experience with adjuvant nivolumab. PATIENTS AND METHODS: We conducted a retrospective, observational cohort study of patients with OEC/GEJC who received adjuvant nivolumab after neoCRT and radical resection between January 2022 and December 2023. Data on patient characteristics, treatment completion, disease progression, and immune-related adverse events (irAEs) were collected from medical records and analysed via descriptive statistics. RESULTS: A total of 17 patients were included. The median follow-up was 34.6 months (range 11.2-55.7). The cohort included 14 (82%) males, with a mean age of 59 years. The Eastern Cooperative Oncology Group (ECOG) performance status was 0 for 15 (88%) patients and 1 for 2 (12%) patients. The tumor location was the esophagus in 9 (53%) patients and the gastroesophageal junction in 8 (47%) patients. At diagnosis, 13 (76%) patients were stage III (8th TNM classification). Histology revealed adenocarcinoma (AC) in 12 (71%) patients and squamous cell carcinoma (SCC) in 5 (29%) patients. Only 6 (35%) patients completed one year of adjuvant nivolumab. Treatment was discontinued in 5 (29%) patients due to disease progression and in 6 (35%) patients due to irAEs. Overall, 11 (65%) patients experienced irAEs of any grade. Grade 3 or 4 irAEs occurred in 4 (24%) patients: myocarditis G4 in 1 (6%) patient and colitis G3 in 3 (18%) patients. No irAE-related deaths were reported. The median disease-free survival (DFS) was 21.4 months (95% confidence interval [CI], 14.6-28.9). CONCLUSIONS: Real-world data from Slovenia indicate that 65% of patients discontinued adjuvant nivolumab prematurely due to disease progression or irAEs. These findings highlight the need for careful patient selection and monitoring when using adjuvant immunotherapy in this population.