Childhood adrenocortical tumors.

Abstract

The problem From 1966 ‐1996, 73 children under 16 yr of age with adrenocortical tumor were admitted to the Division of Pediatric Endocrinology at the Clinics Hospital, Federal University of Parana, in the city of Curitiba, State of Parana, in southern Brazil. The Clinics Hospital is a tertiary referral center for approximately 10 million inhabitants, 3.5 million of whom are children less than 15 yr of age. With 12‐14 new cases of childhood adrenocortical tumor (ACT) diagnosed in the State of Parana each year, the annual incidence of ACT within this region can be estimated to range from 3.4 ‐ 4.2/ million children below the age of 15 yr. Remarkably, patients 4 yr of age or less account for the vast majority of cases seen at the Clinics Hospital (Fig. 1). This finding as well as those from other southern Brazilian states suggest an increased incidence of ACT in children (1). By comparison, the annual worldwide incidence of childhood ACT ranges from only 0.3‐ 0.38/million children below the age of 15 yr (2, 3). Definitive explanations for this apparent excess of ACT cases in southern Brazil are presently lacking. The Parana region is located below the Tropic of Capricorn and has no known endemic transmissible diseases. The population is mainly of European extraction (Italy, Poland, and Germany), locales in which the incidence of ACT in children has not been unduly increased. Moreover, compared with other regions of Brazil, this southern state has had the least native Indian influence during colonization. A genetic predisposition toward cancer, which appears to play a role in many childhood tumors, is not a common feature among southern Brazilian families of children with ACT (4). Industrial pollutants, a major contributor to increased rates of solid tumor development, cannot be accorded more than a minor role in the Parana cases due to the slow pace of industrial expansion in this region. However, because of the extensive agricultural activities in southern Brazil, it is possible that environmental pollutants, such as pesticides, may pose a substantial health hazard. Agricultural pesticides are widely used in Parana, usually without safety guidelines. In this regard, British investigators found an association between an increased incidence of ACT and pesticide use in northwestern England (5), whereas in Norway, Kristensen et al. (6) noted an almost 2-fold increase in the relative risk for cancer among children 0 ‐ 4 yr of age whose parents were engaged in agriculture. Taken together, these findings suggest that environmental pollutants may play a causative role in the excessive incidence of childhood ACT in southern Brazil.