(118) Evaluation of Treatment Tolerability Associated with Carboplatin Dose Based on Actual Body Weight Versus Adjusted Body Weight in Patients with a BMI ≥ 25 mg/m2 with Advanced Ovarian Cancer

Poster Abstract:

Background:
The National Comprehensive Cancer Network (NCCN) guidelines recommend utilizing carboplatin and paclitaxel with or without bevacizumab as the preferred treatment regimen for patients with stages II-IV epithelial ovarian cancer. Carboplatin is primarily eliminated via urinary excretion; therefore, a patient’s overall exposure to the medication is correlated with renal clearance. The Calvert equation was developed as a formula to allow clinicians to dose carboplatin in a way that targets a specific area under the curve (AUC) based on an individual’s glomerular filtration rate (GFR). There is controversy among treating clinicians and national guidelines about whether it is preferable to use actual body weight or adjusted body weight when calculating GFR for overweight patients with a body mass index (BMI) of 25 kg/m2 or greater. The NCCN and Gynecologic Oncology Group (GOG) guidelines recommend using adjusted body weight to calculate creatinine clearance in patients with a BMI of 25 kg/m2 or greater. However, the American Society of Clinical Oncology (ASCO) recommends using actual body weight when calculating chemotherapy doses in obese patients. ASCO states that using actual weight-based cytotoxic chemotherapy for obese patients does not increase toxicity and may result in decreased efficacy. Both dosing strategies are utilized in clinical practice depending on clinician preference.

Objectives:
The aim of this study is to describe the composite incidence of dose reductions, treatment delays or omissions due to toxicity, early discontinuation, or the need for granulocyte colony-stimulating factor (G-CSF) support associated with carboplatin dosing utilizing actual body weight compared with adjusted body weight in patients with advanced epithelial ovarian cancer receiving neoadjuvant or adjuvant carboplatin and paclitaxel with or without bevacizumab.

Methods:
This study is a retrospective descriptive analysis. Patients with advanced epithelial ovarian cancer and a BMI ≥ 25 kg/m2 who received treatment with carboplatin and paclitaxel were included. Patient charts were reviewed to determine the incidence of dose reductions, treatment delays due to toxicity, and/or the need for growth factor support associated with carboplatin dosing utilizing actual body weight compared to adjusted body weight. Additionally, data was collected to determine the incidence of grade 3 or higher hematologic toxicity associated with both dosing strategies.

Results:
Data collection has been completed; however, data analysis is pending.
Discussion/conclusions:
The results of this research will contribute to the current body of literature regarding the appropriate dosing of carboplatin in obese patients and help standardize dosing practices.

References (must also be included in final poster): 1. Cancer O. NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines ® ) NCCN.org NCCN Guidelines for Patients ® available at www.nccn.org/patients. Published online 2023. Accessed July 23, 2023. www.nccn.org/patients
2. Perren TJ, Swart AM, Pfisterer J, et al. A Phase 3 Trial of Bevacizumab in Ovarian Cancer. New England Journal of Medicine. 2011;365(26):2484-2496.
3. NCCN Chemotherapy Order Templates (NCCN Templates ® ) Appendix B Carboplatin Dosing in Adults. Accessed July 16, 2023. https://wayback.archive-
4. GOG_Appendix 5 Carboplatin Dosing 6-20-11.
5. NCCN Chemotherapy Order Templates (NCCN Templates ® ) Appendix B Carboplatin Dosing in Adults. Accessed July 24, 2023. https://wayback.archive-
6. Griggs JJ, Mangu PB, Anderson H, et al. Appropriate chemotherapy dosing for obese adult patients with cancer: American Society of Clinical Oncology clinical practice guideline. Journal of Clinical Oncology. 2012;30(13):1553-1561. doi:10.1200/JCO.2011.39.9436
7. Wright JD, Tian C, Mutch DG, et al. Carboplatin dosing in obese women with ovarian cancer: A Gynecologic Oncology Group study. Gynecol Oncol. 2008;109(3):353-358. doi:10.1016/j.ygyno.2008.02.023
8. Ozols RF, Bundy BN, Greer BE, et al. Phase III trial of carboplatin and paclitaxel compared with cisplatin and paclitaxel in patients with optimally resected stage III ovarian cancer: A Gynecologic Oncology Group study. Journal of Clinical Oncology. 2003;21(17):3194-3200. doi:10.1200/JCO.2003.02.153
9. Martin AL, Colin-Leitzinger CM, Sinha SK, Chern JY, Peres LC. Impact of obesity on chemotherapy dosing of carboplatin and survival of women with ovarian cancer. British Journal of Cancer 2023 128:12. 2023;128(12):2236-2242. doi:10.1038/s41416-023-02259-1