Solid tumors in Turkish children: a multicenter study.

BACKGROUND This paper presents a detailed incidence study on childhood solid tumors comprising a histopathology-based documentation of benign and malignant lesions. METHODS The Ankara Pediatric Pathology Working Group collected databases of pediatric solid tumors from six pediatric reference centers in order to analyze the incidence, distribution and some epidemiologic characteristics of the tumors and to establish a multicenter database for further studies. A five-year retrospective archive search was carried out. Excluding epithelial tumors of the skin, leukemia, lymphoreticular system neoplasias, metastatic tumors, and hamartomas, 1362 solid tumors in 1358 patients were classified according to age, sex, localization, histopathology and clinical behavior. RESULTS The male/female ratio was 0.9; 14.8% (201) of the patients belonged to 0-1 year age group, 20.7% (281) to 2-4 years, 25.9% (352) to 5-10 years, 22.2% (301) to 11-14 years, and 16.4% (223) to 15-18 years. Among all tumors, 708 (52.0%) were malignant, 645 (47.4%) benign tumors, 2 (0.1%) borderline tumors, and 2 (0.1%) unknown behavioral tumors. Malignant tumors were found in 50.2% (357) of female patients and in 54.0% (349) of male patients. A balanced distribution between benign and malignant entities among children under 18 years was observed. Comparison between the age groups revealed malignant cases outnumbered benign cases under 4 years of age while benign tumor numbers increased after 10 years of age. The most common entities in the malignant group were of sympathetic nervous system origin, while soft tissue tumors far outnumbered the others in the benign group. CONCLUSIONS We conclude that the cancer patterns of children in the Ankara region mostly resemble with those of the western population. This study provides useful information on the diagnosis of solid tumors in children and highlights variations in cancer incidence in different age groups.