[Cases of Advanced Colorectal Cancer with Nephrotic Syndrome after FOLFIRI plus Ramucirumab Administration].

We report 2: Cases of advanced colorectal cancer that developed nephrotic syndrome after ramucirumab(RAM)administration. Case 1: A 54-year-old woman with rectal cancer, liver and lung metastases, and peritoneal dissemination underwent sigmoid colon double-barrel colostomy for perforation management. The patient received 15 postoperative CAPOX plus bevacizumab(Bev)courses. FOLFIRI plus RAM was introduced as the second-line treatment. After 2 courses, the patient showed marked proteinuria and hypoalbuminemia and was diagnosed with nephrotic syndrome. The patient's condition improved promptly with administrating diuretics and antihypertensive drugs. Case 2: A 72-year-old man underwent sigmoid colon cancer resection with duodenal infiltration. Despite the treatment, a tumor was identified at the radial margin(RM1), with a positive cytological test(CY1)result. Therefore, postoperative mFOLFOX6 plus Bev was administered for 17 courses. FOLFIRI plus RAM was introduced as the second-line treatment due to residual tumor growth. After 2 courses, the patient showed accentuated proteinuria and was diagnosed with nephrotic syndrome and heart failure. The patient's condition improved after administrating diuretics, antihypertensive drugs, and V2-receptor antagonists. In both cases, marked proteinuria was observed after shifting to second-line treatment with two RAM administrations. Therefore, monitoring nephrotic syndrome development during the early RAM introduction stage is essential.