近年来，胃癌治疗效果有所改善；然而，其在青少年和年轻人中的特征尚不清楚。我们报告一例患有晚期胃癌、范可尼贫血 (FA) 和原发性胆汁性胆管炎的患者。一名 26 岁的女性因上腹痛去看当地医生。食管胃十二指肠镜检查显示胃体水肿、扩张不良、皱襞环增厚、糜烂。病变标本的活检结果显示低分化腺癌。腹部增强计算机断层扫描显示胃壁厚度不规则，腹腔内有多个结节，右侧卵巢有肿块病变。我们诊断该患者为T4N2M1 IV期胃癌，伴有腹膜和卵巢转移，并开始纳武单抗联合S-1加奥沙利铂作为一线治疗方案。因1个疗程全身治疗后出现免疫相关不良事件，方案改为雷莫芦单抗联合白蛋白结合型紫杉醇化疗作为二线治疗。每周接受白蛋白结合型紫杉醇联合雷莫芦单抗三个周期后，减少的血小板计数并未恢复，她的一般状况逐渐恶化。使用下一代测序进行全面的基因组分析，以确定基因型匹配疗法的可行性。鉴定出 FA 互补组 A (FANCA) F1263del (49.1%) 和 E484Q (12.3%) 的变化，它们编码多蛋白 FA 复合物的关键成分。患者在开始治疗 10 个月后死亡。总之，在治疗青少年和年轻成年患者的恶性肿瘤时，应考虑基因组背景。© 2023。日本胃肠病学会。

Recently, the results of gastric cancer treatment have improved; however, its characteristics in adolescents and young adults are not well known. We report the case of a patient with advanced gastric cancer, Fanconi anemia (FA), and primary biliary cholangitis. A 26-year-old woman visited a local physician complaining of epigastralgia. Esophagogastroduodenoscopy revealed edematous changes with poor distension and circumferential thickened folds with erosions in the gastric body. Biopsy results of the lesion specimens revealed poorly differentiated adenocarcinoma. Abdominal contrast-enhanced computed tomography revealed gastric wall with irregular thickness, several nodules in the peritoneal cavity, and a mass lesion in the right ovary. We diagnosed the patient with T4N2M1 stage IV gastric cancer accompanied by peritoneal and ovarian metastases and initiated nivolumab with S-1 plus oxaliplatin as the first-line treatment regimen. Because of immune-related adverse events after one course of systemic treatment, the regimen was changed to ramucirumab combined with nab-paclitaxel chemotherapy as the second-line treatment. After three cycles of weekly nab-paclitaxel with ramucirumab, the decreased platelet count did not recover, and her general condition gradually deteriorated. Comprehensive genome profiling using next-generation sequencing was performed to determine the feasibility of genotype-matched therapies. Alterations in FA complementation group A (FANCA) F1263del (49.1%) and E484Q (12.3%), which encode a key component of the multiprotein FA complex, were identified. The patient died 10 months after treatment initiation. In conclusion, when treating malignancies in adolescent and young adult patients, the genomic background should be considered.© 2023. Japanese Society of Gastroenterology.