DOSE REDUCTION, RELATIVE DOSE INTENSITY AND TREATMENT TOXICITY IN CERVICAL CANCER PATIENTS UNDER CISPLATIN AND RADIOTHERAPY TREATMENT

Introduction: Studies show that obese patients tend to be submitted to empiric chemotherapy dose reduction, aiming to attenuate adverse effects of the treatment. However, findings suggest that this practice is possibly related to worse clinical outcomes and there is no evidenceof severe toxicity with fulldose administration in this population. Objective: To describe the relationship between body mass index (BMI) with capping dose, relative dose intensity (RDI) and treatment toxicity in cervical cancer patients. Method: The sample consisted of 183 cervical cancer patients, older than 18 years, admitted at Cancer Hospital II (INCA) between 2018 and 2019, without previous treatment, with proposal of cisplatin and radiotherapy combined treatment. Sociodemographic, clinical and BMI data were assessed at the first chemotherapy cycle. Chemotherapy toxicity was evaluated as the presence of symptoms > grade 3, according to Common Terminology Criteria for Adverse Events v4.0. Severe toxicity was considered as any adverse event resulting in interruption, delay or dose reduction ( > 15%). Capped dose was analyzed based on the institutional protocol (70mg/week) and RDI was calculated using the formula: (delivered dose/treatment duration) ÷ (prescribed dose/planned treatment duration). The analyses were considered statistically significant if p-value < 0,05. Results: The mean age of the patients was 47 years (± 12,6 years). Of total, 87,4% showed squamous cell carcinoma histological type and 43,7% had cancer stage II. Excess of weight was found in 61,8% (33,9% overweight and 27,9% obesity). Regarding treatment, capped dose was identified in 42,6%, toxicity > 3 in 59% and severe toxicity in 24,6%. Over 90% of the obese patients had capped dose, and the prevalence of toxicity was similar among BMI ranges, regardless the capped dose (89,3% vs. 91,3% for obesity and 44,4% vs. 42,3% for overweight). In addition, 6% of the patients received less than 85% of the prescribed dose, of which all were obese. All analyzes were statistically significant. Conclusion: Given the high prevalence of excess weight, and since toxicity frequencies were similar between BMI ranges, regardless the capped dose in the studied population, it is suggested further studies evaluating the evidence of empiric dose reduction in these patients aiming to avoid treatment toxicity. Also, the impact of capped dose on cervical cancer prognosis should be investigated in the future.