Novel Ambulatory Treatment With Portable Infusion Pump for 5-Fu in Immunochemotherapy for Esophageal Cancer: Impact on Survival and Treatment Intensity

Background The combination of immune checkpoint inhibitors (ICI) with fluorouracil (5-FU) and cisplatin (CDDP) has improved survival in esophageal cancer. However, the optimal duration for combining cytotoxic agents with ICI remains unclear. Additionally, in clinical practice, administering 5-FU on days 1 through 5 is often unacceptable to patients, as it requires hospitalization for each dose. To address this, a new ambulatory treatment regimen using a portable continuous infusion pump for 5-FU and a short hydration method for CDDP was developed. We assessed how maintaining the intensity of cytotoxic treatment with ICI affects patient survival. Methods Patients who received the triplet therapy of ICI with 5-FU plus CDDP at Nagoya City University Hospital between March 2022 and April 2024 were included in this study and divided into two groups: one as the pump method group that continued the treatment with portable continuous infusion pump for 5-FU after the termination of CDDP administration and the other as the conventional method group that continued without infusion pump. Kaplan–Meier curves were used to describe progression free survival (PFS) and overall survival (OS). Incidence of treatment-related adverse events were also evaluated. Results The number of eligible patients were 19 in the pump group and 13 in the conventional group. Age and performance status did not differ. The number of treatment cycles with ICI plus 5-FU after CDDP cessation in the pump group was significantly higher. PFS and OS were significantly longer in the pump group than the conventional group (median PFS (months) [95%CI]: 9.1 [6.37–17.38] vs 5.6 [1.71-NA], P = 0.015; median OS (months) [95%CI]: 17.5 [6.4–17.4] vs 7.2 [2.27-NA], P = 0.024, Log-rank test.). The incidence of any grade and grade ≥ 3 treatment-related adverse events were no significant difference between the both groups (Fisher’s t-test). Conclusion Ambulatory treatment in ICI plus 5-FU with portable continuous infusion pump after cessation of CDDP administration can be a promising option for outpatients with esophageal cancer to continue the doublet therapy with ICI plus 5-FU. Consequently, the continuation of 5-FU with ICI may contribute to maintaining anti-tumor responses and survival benefits due to the higher treatment intensity.