Effects of unidentified renal insufficiency on the safety and efficacy of chemotherapy for metastatic colorectal cancer patients: a prospective, observational study

This is a single-center, prospective, observational study aiming to determine the effects of unidentified renal insufficiency (URI) on the safety and efficacy of chemotherapy for metastatic colorectal cancer (mCRC) patients. mCRC patients with normal serum creatinine and who were treated with CapeOx as the first-line therapy were included. Creatinine clearance (CrCL) was estimated using the Cockcroft-Gault formula. URI was characterized by a CrCL of less than 60 ml/min. Logistic regression was used to assess the effects of URI on toxicities and response rates. Kaplan-Meier curve was used to evaluate the effect of URI on survival. A total of 143 patients were enrolled, of whom 34.9 % had URI. Compared with the control group, the URI group had longer toxicity durations and developed significantly more grade 1 to 2 toxicities after adjusting for age, gender, and body mass index. The toxicities include cytopenia (76 vs. 61 %, OR = 1.86, 95 % CI = 0.39-2.53, P < 0.001), diarrhea (34 vs. 29 %, OR = 3.76, 95 % CI = 0.95-6.53, P = 0.007), stomatitis (10 vs. 6 %, OR = 2.81, 95 % CI = 1.10-4.28, P = 0.002), and hand-foot syndrome (18 vs. 11 %, OR = 2.56, 95 % CI = 0.86-5.41, P = 0.045). The response rate and time to progression were significantly lower in the URI group than in the control group (4.5 vs. 5.5 months, HR = 1.57, 95 % CI = 1.09-2.25, P = 0.015), whereas the overall survival rates of the two groups were similar. In conclusion, URI can increase the toxicity and decrease the TTP of CapeOx-treated mCRC patients. Renal function screening via CrCL estimation is required for all mCRC patients before initial chemotherapy.