Gonzalez Diez Beatriz, Fernandez Aceñero Maria Jesus, Mendez Ramiro Jesus, Martin-Antona Esteban, Sastre Javier
Medical Oncology, Hospital Clínico San Carlos, Madrid, ESP.
Pathology, Hospital Clínico San Carlos, Madrid, ESP.
Cureus. 2024 Jun 30;16(6):e63527. doi: 10.7759/cureus.63527. eCollection 2024 Jun.
The standard of care for patients with operable gastric adenocarcinoma is perioperative chemotherapy and surgical resection. The deficient mismatch repair (dMMR)/microsatellite instability (MSI-H) phenotype is a major predictive biomarker for immune checkpoint inhibitors (ICIs) efficacy in advanced disease. Several phase II and III trials suggest a promising future role of immunotherapy with or without chemotherapy in the neoadjuvant/adjuvant setting, especially in MSI-H localized gastric adenocarcinomas. We present a 38-year-old man diagnosed in March 2022 with poorly differentiated gastric adenocarcinoma clinical stage III (cT4 N0 M0) with deficiency of MLH1 and PMS2, combined positive score (CPS) of 100 and negative HER2 immunohistochemistry, had poor tumor response to preoperative 5-FU, leucovorin, oxaliplatin, and docetaxel (FLOT). It was considered unresectable because of the involvement of the colon, mesocolon, duodenum, pancreas, and retroperitoneum. Then, first-line systemic treatment with 5-FU, leucovorin, and oxaliplatin (FOLFOX)-nivolumab was initiated in August 2022, with a significant radiologic tumor reduction after six cycles, allowing a curative surgery in March 2023 with complete pathologic tumor response, followed by capecitabine and nivolumab for one year, maintaining radiological remission in the last follow-up in April 2024. With this case report, we conclude that it is likely that chemoimmunotherapy or immunotherapy alone may be alternative neoadjuvant treatment choices for MSI-H locally advanced gastric cancer patients.
可手术切除的胃腺癌患者的标准治疗方案是围手术期化疗和手术切除。错配修复缺陷（dMMR）/微卫星高度不稳定（MSI-H）表型是晚期疾病中免疫检查点抑制剂（ICI）疗效的主要预测生物标志物。多项II期和III期试验表明，免疫疗法联合或不联合化疗在新辅助/辅助治疗中具有广阔的应用前景，尤其是在MSI-H局部胃腺癌中。我们报告了一名38岁男性，于2022年3月被诊断为低分化胃腺癌，临床分期为III期（cT4 N0 M0），MLH1和PMS2缺陷，联合阳性评分（CPS）为100，HER2免疫组化阴性，对术前5-氟尿嘧啶、亚叶酸钙、奥沙利铂和多西他赛（FLOT）的肿瘤反应较差。由于结肠、结肠系膜、十二指肠、胰腺和腹膜后受累，被认为无法切除。随后，于2022年8月开始采用5-氟尿嘧啶、亚叶酸钙和奥沙利铂（FOLFOX）-纳武单抗进行一线全身治疗，六个周期后肿瘤在影像学上显著缩小，于2023年3月进行了根治性手术，病理肿瘤完全缓解，随后使用卡培他滨和纳武单抗治疗一年，在2024年4月的最后一次随访中维持影像学缓解。通过本病例报告，我们得出结论，化疗免疫疗法或单独免疫疗法可能是MSI-H局部晚期胃癌患者新辅助治疗的替代选择。
