(112) Evaluation of the impact of two carboplatin dose calculation methods on overall treatment tolerability in gynecologic oncology patients

Background/Rationale:
Carboplatin dosing, based on the Calvert formula, utilizes the desired area under the curve (AUC) and the patient’s estimated glomerular filtration rate (eGFR). In addition to dose capping at 125 mL/min, the Gynecologic Oncology Group (GOG) recommends using adjusted body weight for body mass index (BMI) ≥ 25 kg/m2 and minimum serum creatinine (SCr) of 0.7 mg/dL. The gynecologic oncology department at a community cancer center has switched from the GOG recommendation to using actual SCr when determining carboplatin dose.

Objective(s):
The purpose of this initiative is to assess the impact on patient treatment subsequent to change in carboplatin dose calculations. The primary objective is to evaluate the percent of patients with 0-4 treatment modifications in the pre versus post implementation groups. The secondary objective is to compare the percent of each treatment modification type in pre versus post implementation group. The exploratory objectives will evaluate the percent of patients with cycle 1 G-CSF use, patients with cycle omissions, cycles with maximum carboplatin doses utilized, and cycles with SCr < 0.7 used to calculate the dose.

Methods:
A retrospective electronic health record review will be performed for gynecologic oncology patients at a community cancer center for a period of time before and after the implementation of the new method in carboplatin dosing calculation. All gynecologic oncology patients with planned cycles of carboplatin AUC 5-6 and paclitaxel (135-175mg/m2 ) every 21 days will be included. Patients will be excluded if they are enrolled in clinical trials, use concomitant monoclonal antibodies, and received only one cycle of carboplatin/paclitaxel. The following data points will be collected for each cycle: SCr actual and SCr used for carboplatin dose calculation, AUC, carboplatin and paclitaxel dose, and G-CSF use. A score will be assigned based on having any one or more of the following treatment modifications: AUC reduction, paclitaxel dose reduction, treatment delay, and addition of G-CSF (cycle 2 and beyond). Patients could receive a score of 0 for no modifications and up to a score of 4 if all treatment modifications strategies are utilized. Descriptive statistics will be used to analyze data.

Results: Pending

Conclusions/

Discussion: Pending

1. Samani A, Bennett R, Eremeishvili K, et al. Glomerular filtration rate estimation for carboplatin dosing in patients with gynaecological cancers
[published correction appears in ESMO Open. 2023 Jun;8(3):100640]. ESMO Open. 2022;7(2):100401. doi:10.1016/j.esmoop.2022.100401

2. Calvert AH, Newell DR, Gumbrell LA, et al. Carboplatin dosage: prospective evaluation of a simple formula based on renal function. J Clin
Oncol.1989;7:1748–1756