Liu Yan, Du Junliang, Zhang Pan, Meng Wenjuan, Xiao Haifeng
Oncology Department, Weifang People's Hospital, Weifang Medical University, Weifang, China.
Front Oncol. 2023 Mar 9;13:1051786. doi: 10.3389/fonc.2023.1051786. eCollection 2023.
Primary colon squamous cell carcinoma (SCC) is extremely rare and associated with a poor prognosis. Moreover, there is no treatment guideline for this disease. Proficient mismatch repair/microsatellite-stable (pMMR/MSS) colorectal adenocarcinoma is refractory to immune monotherapy. Although the combination of immunotherapy with chemotherapy in pMMR/MSS colorectal cancer (CRC) is currently under investigation, the clinical activity of this approach in colorectal SCC remains unknown. In this article, we report the case of a pMMR/MSS CRC patient with ascending colon SCC who had high programmed cell death-ligand 1 (PD-L1) expression and the a missense mutation in codon 600 of the B-Raf proto-oncogene (BRAF ) mutation. The patient exhibited a significant response to the combination of immunotherapy and chemotherapy. After eight cycles of treatment with the combination of sintilimab and mFOLFOX6 (oxaliplatin, fluorouracil, and leucovorin), computed tomography-guided microwave ablation of the liver metastasis was performed. The patient achieved excellent durable response and continues to experience a good quality of life. The present case indicates that programmed cell death 1 blockade combined with chemotherapy may be an effective therapy for patients with pMMR/MSS colon SCC and high PD-L1 expression. Furthermore, PD-L1 expression may be a biomarker for immunotherapy in patients with colorectal SCC.
原发性结肠鳞状细胞癌（SCC）极为罕见，且预后较差。此外，针对该疾病尚无治疗指南。错配修复功能正常/微卫星稳定（pMMR/MSS）的结直肠癌对免疫单药治疗无效。尽管目前正在研究免疫治疗与化疗联合用于pMMR/MSS结直肠癌（CRC）的疗效，但这种方法在结肠SCC中的临床活性仍不清楚。在本文中，我们报告了1例pMMR/MSS CRC伴升结肠SCC患者的病例，该患者程序性细胞死亡配体1（PD-L1）表达高，且B-Raf原癌基因（BRAF）第600密码子存在错义突变。该患者对免疫治疗与化疗联合治疗表现出显著反应。在用信迪利单抗和mFOLFOX6（奥沙利铂、氟尿嘧啶和亚叶酸钙）联合治疗8个周期后，对肝转移灶进行了计算机断层扫描引导下的微波消融。患者获得了极佳的持久缓解，生活质量持续良好。本病例表明，程序性死亡1阻断联合化疗可能是治疗pMMR/MSS结肠SCC且PD-L1表达高的患者的有效疗法。此外，PD-L1表达可能是结肠SCC患者免疫治疗的生物标志物。
