Statistical analysis of central nervous system tumors in China.

The authors present a statistical survey of the general incidence, age distribution, and preferential sites of 25, 122 tumors of the central nervous system (CNS), from 12 centers in China. Of these tumors, 22,457 were intracranial and the rest intraspinal. Of the 22,457 intracranial neoplasms collected tumors of neuroepithelial tissue comprised 43.85%, meningiomas 16.58% tumors of nerve sheath cells 9.5%, pituitary adenoma 9.52%, congenital tumors 8.46%, secondary tumors 6.8%, vascular malformations and tumors 3.82%, and primary sarcomas 0.72%. Neuroepithelial and meningeal tumors occurred first and second in all series, but the other tumors varied in frequency. There was a higher incidence of nerve-sheath tumors in southern than in northern regions. The age distribution of Chinese patients with tumors of the CNS was lower than that of Caucasians: nearly two-thirds (64.57%) had the clinical onset of their tumor between the ages of 31 and 40 years, with the peak incidence at 35 years. Nearly 20% of tumors of the CNS occurred before 20 years of age. The male:female ratio was 1.53:1; the only tumor with a definite preponderance of females over males was the meningioma. Intraspinal tumors derived from nerve sheaths comprised 47.13% of all tumors within the spinal canal. Meningiomas were second with an incidence of 14.06%, then followed congenital tumors (12.06%) and neoplasms of neuroepithelial tissue (10.83%). Secondary tumors, vascular malformations and neoplasms, and sarcoma were next in order of frequency with 4.6%, and 4.16%, respectively.