加藤 宏之

BACKGROUND: Biliary tract cancer (BTC) is a type of malignancy that is challenging to manage. Further, advanced-stage BTC has poor prognosis. Based on the recent TOPAZ-1 trial, adding durvalumab to gemcitabine and cisplatin significantly improves survival in unresectable BTC, thereby making it the new standard first-line treatment. However, real-world data are essential to validate its efficacy and safety in routine clinical settings, which often involve older patients and those with comorbidities or previous therapies. This study aimed to evaluate the outcomes of combination chemotherapy with gemcitabine, cisplatin, and durvalumab (GCD) in a real-world cohort with BTC. METHODS: This retrospective analysis included patients with unresectable advanced-stage BTC treated with GCD between December 2022 and April 2024 at three institutions. GCD was administered for up to eight cycles, followed by durvalumab monotherapy. Clinical data, including the characteristics of the patients, adverse events, and treatment responses, were collected. The Kaplan-Meier method and the Cox proportional hazards model were used to assess progression-free survival (PFS), overall survival (OS), and other factors affecting outcomes. RESULTS: The current study included 54 patients with a median age of 72 years. Half of the patients had recurrence post-surgery, and many of them had previously received chemotherapy. The median PFS and OS rates were 4.1 and 8.0 months, respectively. Adverse events (AEs) were frequently observed, with 42.1% of patients presenting with grade 3 or higher AEs. However, immune-related AEs were rare and mild. Dose adjustments, which are often caused by renal impairment or fatigue, were common (66.7%). Multivariate analysis revealed that older age, a lower performance status score, and a high neutrophil-to-lymphocyte ratio (NLR) were significant predictors of a shorter PFS. Further, a lower performance status score, and a high NLR were associated with a low OS. CONCLUSIONS: GCD combination chemotherapy is a viable treatment option for advanced-stage BTC in a real-world setting where dose modifications can improve tolerability among elderly patients. Neutrophil-to-lymphocyte ratio can be a prognostic biomarker of OS in patients with BTC receiving immune checkpoint inhibitors. This finding highlights the potential of individualized treatment strategies. Nevertheless, further research should be performed to validate these results in larger cohorts.

This study aimed to validate the DFS (direct fast scarlet) staining in the diagnosis of EC (eosinophilic colitis). The study included 50 patients with EC and 60 with control colons. Among the 60 control samples, 39 and 21 were collected from the ascending and descending colons, respectively. We compared the median number of eosinophils and frequency of eosinophil degranulation by HE (hematoxylin and eosin) and DFS staining between the EC and control groups. In the right hemi-colon, eosinophil count by HE was useful in distinguishing between EC and control (41.5 vs. 26.0 cells/HPF, p < 0.001), but the ideal cutoff value is 27.5 cells/HPF (high-power field). However, this method is not useful in the left hemi-colon (12.5 vs. 13.0 cells/HPF, p = 0.990). The presence of degranulation by DFS allows us to distinguish between the groups even in the left hemi-colon (58% vs. 5%, p < 0.001). DFS staining also enabled a more accurate determination of degranulation than HE. According to the current standard to diagnose EC (count by HE staining ≥20 cells/HPF), mucosal sampling from left hemi-colon is problematic since the number of eosinophils could not be increased even in EC. Determination of degranulated eosinophils by DFS may potentiate the diagnostic performance even in such conditions.