MRP1 expression in CTCs confers resistance to irinotecan-based chemotherapy in metastatic colorectal cancer.

摘要: Circulating tumor cells are important markers of progression and can reflect behavior in metastatic colorectal cancer (mCRC). Identification proteins that confer resistance to treatment is an step predict response better selection for patients. Multidrug resistance-associated protein 1 (MRP1) 4 (MRP4) play a role irinotecan-resistance, Excision Repair Cross-Complementation group (ERCC1) expression platinum compounds. Here, we included 34 patients with mCRC most them received FOLFIRI or FOLFOX chemotherapy (91.1%). CTCs were isolated by ISET(®) Technology identified 30 (88.2%), median 2.0 CTCs/mL (0-31.0). We analyzed the immunocytochemical MRP1, MRP4 ERCC1 only who had previously detectable CTCs, accordingly (n = 19, 15 13 patients, respectively). Among treated irinotecan-based chemotherapy, out 19 cases MRP1 positive showed worse free survival (PFS) comparison those negative (2.1 months vs. 9.1 months; p = 0.003). None other studied significant association PFS. also histological sections primary tumors metastases immunohistochemistry, found no clinicopathological characteristics Our results show as potential biomarker irinotecan when from This small proof-of-principle study these early findings need be validated larger cohort