case_images: PMC9792834_01
case_images: Computed tomography revealed multiple rim-enhancing (A) peritoneal metastases and (B) liver metastases before low-dose nivolumab. A durable complete response (C, D) was maintained after more than 1 year of nivolumab-based treatment.
case_images: fimmu-13-1077840-g001.jpg
case_images: PMC9792834_01_fimmu-13-1077840-g001.jpg
case_images: f1
case_images: The expression of MSH2 and PMS2 was preserved ( Supplementary Figure 1 ). With ongoing low-dose nivolumab plus S-1 and leucovorin for more than 1 year, CR has been maintained ( Figures 1C, D ), and she has remained asymptomatic with gradually recovered renal function.
case_images: With a short duration of low-dose nivolumab plus gemcitabine (G), cisplatin (C), S-1 (S), and leucovorin (L), the level of CA 19-9 decreased rapidly with a complete response of tumors, which was durable under the maintenance therapy with low-dose nivolumab plus de-escalated chemotherapy (S-1 and leucovorin). (F, fluorouracil; Na, nanoliposomal irinotecan; Nab-P, nab-paclitaxel).
case_images: fimmu-13-1077840-g002.jpg
case_images: PMC9792834_01_fimmu-13-1077840-g002.jpg
case_images: f2
case_images: The treatment course is summarized in  Figure 2 .