Case Report: Biweekly TAS-102 and bevacizumab as maintenance therapy for recurrent and metastatic pseudomyxoma peritonei following palliative cytoreduction.

Introduction: Recurrence of pseudomyxoma peritonei (PMP) with pulmonary and lymphatic metastases occurs only rarely in clinical practice, making the selection of an appropriate postoperative chemotherapy regimen essential for managing these complex cases. Case presentation: We describe an 83-year-old woman with an appendiceal pseudomucinous tumor who developed a recurrence 2 years after initial surgery, presenting with bilateral lung metastases and multiple lymph node metastases. Palliative cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) was performed to relieve intestinal obstruction. Given the patient's advanced age and the complexity of the procedure, the completeness of the cytoreduction score was 2, and the peritoneal cancer index (PCI) was 10. Postoperative pathology confirmed a high-grade mucinous adenocarcinoma of appendiceal origin. After initiating a biweekly regimen of trifluridine/tipiracil (TAS-102) combined with bevacizumab, the patient achieved disease stabilization for approximately 5 months, with stable tumor marker levels and no evidence of radiological progression. Conclusion: This case underscores the therapeutic challenges of recurrent PMP with bilateral pulmonary and multiple lymph node metastases. A biweekly regimen of TAS-102 plus bevacizumab may represent a viable maintenance option when surgery and conventional chemotherapy regimens prove unsatisfactory.