562 Background: Neutropenia is a major factor affecting the continuation of chemotherapy for colorectal cancer. In many clinical trials, a neutrophil count of more than 1500 is targeted for the continuation of chemotherapy; for a count of less than 1500, medication is commonly discontinued. However, there is no definite evidence for setting the targeted neutrophil count at 1500. In our department, chemotherapy is discontinued when the neutrophil count is less than 1000 (Grade 3); for a count of 1000 to 1500 (Grade 2), chemotherapy is continued. We examined the neutrophil count during continuation of chemotherapy in patients with a count of 1000 to 1500, and verified whether these neutrophil counts warrant discontinuation of medication. Moreover, we examined the neutrophil count during the previous course of chemotherapy when it fell below 1000. Methods: The study included 104 patients who received XELOX + bevacizumab (BV) therapy, XELOX therapy, and XELIRI + BV therapy for advanced or recurrent colorectal cancer. Results: The patients with a neutrophil count of 1000 to 1500 were 26 (23.1%) of the total. Two (7.7%) of 26 patients had a neutrophil count of less than 1000 during the following course of chemotherapy. Moreover, among the patients with a neutrophil count of less than 1000, 25% had a count of 1000 to 1500 during the previous course of chemotherapy and 75% had a count of more than 1500. Conclusions: According to these results, Grade 2 neutropenia cannot predict the risk of the Grade 3 neutropenia. Continuation of chemotherapy in patients with a neutrophil count of 1000 to 1500 may be appropriate, and discontinuation of therapy is not always required.
Plasma exosomal microRNA‑125b as a monitoring biomarker of resistance to mFOLFOX6‑based chemotherapy in advanced and recurrent colorectal cancer patients
