Risco de recorrência em Sistema Nervoso Central de Linfoma Difuso de grandes células B e sua profilaxia em Serviço Público de Saúde em dois centros no Brasil

Abstract

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma. Central nervous system (CNS) relapse is a rare event, varying from 5% to 10%, according to risk factors previously defined through the CNS International Prognostic Index(CNS-IPI) and specific extranodal sites. It presents unsatisfactory outcomes, with a median overall survival of two to five months. Over the years, several strategies to reduce CNS relapse have been evaluated, and they are increasingly controversial. Prophylaxis to prevent CNS relapse frequently used differs in the form of administration, based on intrathecal methotrexate (IT-MTX) or high-dose systemic (HD-MTX), associated or not with other chemotherapeutic agents. The studies available so far were carried out in high-income countries and it is questioned whether limitations found in economic transition countries, with greater difficulty in accessing diagnostic and therapeutic methods, would have an impact or could justify prophylaxis for CNS relapse. We carried out a retrospective study in two public health centers in Belo Horizonte, Brazil, between January 2018 and July 2022, to evaluate the incidence of CNS relapse in patients affected by DLBCL. We estimated progression-free survival and overall survival. A total of 120 patients, with a mean age of 54.4 ± 15.4 years and a predominance of males (60.0%) were evaluated in the study. Of these, only seven (5.8%) received IT-MTX and four (3.3%) received HD-MTX. There were no patients who received both routes of prophylaxis. The prognostic score for initial risk of CNS relapse by CNS-IPI was estimated as: low [0-1; 37 (30.8%)], moderate [2-3; 53 (44.2%)] or high [≥ 4; 27 (22.5%)]. CNS relapse was confirmed in four (3.3%) patients. Although the study was carried out in oncohematological reference centers, the number available was small considering the rarity of the event. We were unable to demonstrate whether or not there is benefit from specific prophylaxis for CNS relapse. Considering the morbidity and mortality of this complication, it is suggested to carry out further studies and investigate occult CNS involvement in DLBCL at diagnosis.