Eventos adversos da quimioterapia anticâncer em pacientes pediátricos com tumores do sistema nervoso central: estudo retrospectivo

Abstract

In Brazil, tumors are among the five leading causes of non-violent death. Antineoplastic chemotherapy (CT) may be used prior to surgical resection or later, along with radiotherapy (RT). Adverse events of CT depends on factors such as CT intensity, drug combination and mechanism of action, tumor’s location and behavior, patient’s age and comorbidities. The purpose of this study was to assess the prevalence of these events in CNS tumor patients treated with CT protocols, at Pediatric Cancer Center, Hospital Infantil Albert Sabin (HIAS). Frequency of adverse events was analyzed. The study included patients with malignant tumors of the CNS aged 0-18 years, who started treatment between January 2007 and December 2010. In addition to the adverse events, treatment modalities were also studied (CT, RT and surgery). To categorize the data, it was used the translated Common Toxicity Criteria, from the National Cancer Institute. During the study period, 145 patients aged 0-18 years were diagnosed with primary CNS tumor at HIAS, of which 91 received chemotherapy. Eight CT protocols were used, the most frequent were COG-A9952 (47 patients), SLAOP (19 patients) and SOBOPE 1998 (15 patients, who received CT/RT). Adverse events during chemotherapy occurred in 53 patients (58.2% of 91), the most common being hematologic toxicity (28.6%) and infection (24.2%). Fifteen patients (16.5%) died due to treatment complications,. Severe hearing loss may have occurred due to high cumulative doses of cisplatin. The results showed a lower frequency of adverse events than expected by clinical trials publications, probably due to its retrospective nature and underreporting. The occurrence of cerebral bleeding may be related to the use of valproic acid as a prophylactic antiepileptic, which should be reevaluated. A great number of possibly treatment-related deaths did occur, and this may be related to the use of SLAOP and SOBOPE 1998 protocols. The high number of purported treatment-related deaths contrasts with the relatively low number of adverse events, which suggests the underreporting of adverse events.