The effect of weight-based chemotherapy dosing in a cohort of gynecologic oncology patients

Objective: Many clinicians limit chemotherapy doses based on a maximum body surface area (BSA) of 2m(2). We sought to determine how chemotherapy-related toxicities compared between groups of patients that varied with respect to BSA. We hypothesized that obese patients receiving weight-based (WB) dosing would not have significantly higher chemotherapy-related toxicities than control groups.

Methods: We performed a retrospective review of patients with BSA≥2m(2) who received WB chemotherapy for a gynecologic cancer between January and August 2013. Subjects were matched with two controls: patients with BSA<2m(2) who received WB dosing, and patients with BSA≥2m(2) who received capped dosing at BSA=2m(2). Groups were matched for medical co-morbidities and prior cancer treatment. Demographic and clinical information was extracted and analyzed via ANOVA and Fisher's exact test.

Results: A total of 75 patients were included. The three groups were similar in their medical co-morbidities and prior cancer treatment. When comparing pre- and post-treatment laboratory values, there was no difference in hematologic toxicities. There was no difference between groups with regard to treatment delays, unplanned admissions, transfusions, or dose reductions for toxicity.

Conclusions: Gynecologic cancer patients with BSA≥2m(2) treated with WB chemotherapy had no increase in hematologic or non-hematologic toxicities when compared to controls. Consideration should be given to using WB dosing in obese patients with gynecologic malignancies. Further investigation is required to determine the effect of WB dosing on progression-free and overall survival in obese gynecologic cancer patients.