Concentrations of Irinotecan and SN-38 in the Ascites and the Fluid Product of Cell-Free and Concentrated Ascites Reinfusion Therapy 9 Days After Administration of Irinotecan in a Patient with Gastric Cancer: A Case Report.

Introduction: Cell-free and concentrated ascites reinfusion therapy (CART) is frequently used to relieve the symptoms caused by massive ascites due to peritoneal metastasis of gastric cancer, especially in the later stages of its clinical course. Irinotecan (CPT-11) is recommended for third- or later-line chemotherapy according to gastric cancer treatment guidelines. However, the concentrations of anti-cancer drugs in the ascites and the product of CART are not well known, it is considered that some amounts of anti-cancer drugs contained in the product of CART may be readministered and induce severe adverse reactions.

Case presentation: A 66-year-old female with gastric cancer and massive ascites received third-line chemotherapy with CPT-11 (150 mg/m²) and ramucirumab (8 mg/kg). On day 7, the laboratory test showed a white blood cell count of 1,290/µL and neutrophil count of 480/µL. On day 9, the patient underwent CART, and the concentrations of CPT-11 and its active metabolite 7-ethyl-10-hydroxycamptothecin (SN-38) were 1.18 ng/mL and 0.22 ng/mL in plasma, 0.95 ng/mL and 0.82 ng/mL in ascites, and 0.20 ng/mL and 0.17 ng/mL in the product of CART, respectively.

Conclusion: Concentrations of CPT-11 and SN-38 remaining in ascites and the product of CART were low in an advanced gastric cancer patient 9 days after administration of CPT-11.