Irinotecan plus raltitrexed as second‑line chemotherapy for metastatic colorectal cancer: A retrospective study

The present study evaluated the efficiency, prognostic factors for and the safety of irinotecan combined with raltitrexed (TOMIRI) in patients with metastatic colorectal cancer (CRC). Outcome data of patients who received TOMIRI as first-, second- and third- or later-line treatment regimens were assessed to compare the efficacy of this regimen. Progression-free survival (PFS), overall survival (OS), objective response rate (ORR) and disease control rate (DCR) were evaluated for each group. Kaplan-Meier curves and univariate and multivariate analyses were performed to evaluate efficacy. From January 2017 to December 2019, TOMIRI was administered as a first-line treatment in 23 patients, second-line treatment in 164 patients and third- or later-line treatment in 18 patients. Irinotecan and 5-fluorouracil (FOLFIRI) was administered to another 50 patients, who served as the control group. The median PFS was 9, 7 and 6 months and the median OS was 37, 21 and 17 months for first-, second- and third- or later-line treatments, respectively. The ORRs of the included patients were 21.7, 13.4 and 11.1%, respectively, and the DCRs were 91.3, 81.7 and 66.7%, respectively. Compared with FOLFIRI, TOMIRI as a second-line chemotherapy treatment was associated with longer survival of the patients with CRC. Further analysis demonstrated that pathologic tumor-node-metastasis category, carcinoembryonic antigen, carbohydrate antigen 19-9, treatment cycles, targeted therapy, treatment of local metastases and first-line PFS were prognostic factors for second-line treatment. Among these, the number of treatment cycles was of vital importance. Hepatic dysfunction was the most commonly reported grade 1-2 (55.1%) and grade 3-4 (7.3%) adverse event. Neutropenia (12.2%), thrombocytopenia (10.2%), anemia (27.3%), proteinuria (38.1%) and hematuria (21.0%) were also common grade 1-2 adverse events. In conclusion, TOMIRI may be recommended as an effective and safe second-line treatment for metastatic CRC in the clinic.