[The present status and trend of brain tumors based on the data of the Brain Tumor Registry of Japan].

The Brain Tumor Registry of Japan (BTRJ) was founded in 1974 to investigate the statistical data of brain tumors in Japan. The 12th edition of the report was published as a supplement of the official journal of the Japan Neurosurgical Society, Neurologia medico-chirurgica, in October 2009. It contains the statistical data of 82,844 patients with primary or metastatic brain tumors registered between 1984 and 2000. The data represent the statistics of brain tumors such as the frequency and the anatomical distribution, patient age and sex, and survival rate in the magnetic resonance imaging (MRI) era. Among the registered cases, 65,677 were primary brain tumors. Meningioma was the most frequent, and it accounted for 27.1%, followed by glioma (26.6%), pituitary adenoma (18.2%), and schwannoma (10.5%). Among the patients who were under the age of 15 years the most frequent tumor was glioma (57.2%), while meningioma accounted for 46.3% among those over the age of 70 years. Compared with the data of the Central Brain Tumor Registry of the United States, glioma and meningioma were less frequent and pituitary adenoma and germ cell tumors were much more frequent in Japan. Both statistical registries showed that the frequency of benign brain tumors tends to increase and that of malignant tumors has decreased. In 2009, the BTRJ started the on-line registration, and most cases of brain tumors can be registered with the cooperation of all neurosurgeons in Japan.