Association of creatinine clearance with neutropenia in breast cancer patients undergoing chemotherapy with fluorouracil, doxorubicin, and cyclophosphamide (FAC).

OBJECTIVE

Fluorouracil, doxorubicin, cyclophosphamide protocol (FAC) is a commonly used regimen for breast cancer due to its proven efficacy, acceptable toxicity, high affordability. While hepatic insufficiency dosing for doxorubicin and fluorouracil have been set, there is paucity of data in the literature on how to reduce doses in renal insufficiency. We sought to determine whether there is an association with pre-chemotherapy creatinine clearance, and the occurrence of clinically significant grade 3 to 5 neutropenia during the course of FAC chemotherapy.

METHODS

A retrospective study involving chart review from 2009 to June 2012, of breast cancer patients given FAC was conducted. Demographic profile, pre-chemotherapy complete blood count and creatinine clearance (CrCl) were recorded. Occurrence of Grade 3 to 5 neutropenia was the endpoint of the study. Descriptive statistics, one tailed t test, logistic regression analysis were done between the outcome and variables.

RESULTS

A total of 53 patients were included in the study. The mean age of the patients was 49.77 ± 10.82 years. Patients had an ECOG performance status range of 1 to 3. Patients received mean 5.64 ± 0.92 cycles of FAC protocol chemotherapy. Pre-treatment chemotherapy WBC was 7.41 ± 2.68x109/L, Hemoglobin was 12.60 ± 1.16 g/dL, ANC 4656.89 ± 2379.32. Pre treatment CrCl was 90.79 ± 31.49 ml/min. Thirteen subjects, or 24.53% developed at least grade 3 neutropenia. Patients who developed neutropenia were significantly different from those who did not in terms of baseline WBC p=0.046 and Weight p=0.0119, CrCl p=0.032. Using logistic regression analysis, only creatinine clearance was a significant predictor of neutropenia. There was an inverse association between creatinine clearance and neutropenia, OR 0.887, 95% confidence interval (CI): 0.808- 0.973, p=0.011.

CONCLUSIONS

The study revealed that breast cancer patients treated with FAC, there was an inverse association between creatinine clearance and occurrence of neutropenia.