Objective: Spinal schwannoma remains the third most common intradural spinal tumor following spinal meningioma and ependymoma. The available literature is generally limited to single-institution reports rather than epidemiological investigations. As of 1/1/2004, registration of all benign central nervous system tumors in the United States became mandatory after the Benign Brain Tumor Cancer Registries Amendment Act took action, which provided massive resources for United States population-based epidemiological studies. This article describes the epidemiology of spinal schwannoma in the United States from January 1, 2006, through December 31, 2014.
Methods: In this study, the authors utilized the Central Brain Tumor Registry of the United States, which corresponds to 100% of the American population. The Centers for Disease Control and Prevention's National Program of Cancer Registries and the National Cancer Institute's Surveillance Epidemiology and End Results program provide the resource for this data registry. The authors included diagnosis years 2006 to 2014. They used the codes per the International Coding of Diseases for Oncology, 3rd Edition: histology code 9560/0 and site codes C72.0 (spinal cord), C70.1 (spinal meninges), and C72.1 (cauda equina). Rates are per 100,000 persons and are age-adjusted to the 2000 United States standard population. The age-adjusted incidence rates and 95% confidence intervals are calculated by age, sex, race, and ethnicity.
Results: There were 6989 spinal schwannoma cases between the years 2006 and 2014. The yearly incidence eminently increased between 2010 and 2014. Total incidence rate was 0.24 (95% CI 0.23-0.24) per 100,000 persons. The peak adjusted incidence rate was seen in patients who ranged in age from 65 to 74 years. Spinal schwannomas were less common in females than they were in males (incidence rate ratio = 0.85; p < 0.001), and they were less common in blacks than they were in whites (IRR = 0.52; p < 0.001) and American Indians/Alaska Natives (IRR = 0.50; p < 0.001) compared to whites. There was no statistically significant difference in incidence rate between whites and Asian or Pacific Islanders (IRR = 0.92; p = 0.16).
Conclusions: The authors' study results demonstrated a steady increase in the incidence of spinal schwannomas between 2010 and 2014. Male sex and the age range 65-74 years were associated with higher incidence rates of spinal schwannomas, whereas black and American Indian/Alaska Native races were associated with lower incidence rates. The present study represents the most thorough assessment of spinal schwannoma epidemiology in the American population.
Keywords: APC = annual percentage change; CBTRUS; CBTRUS = Central Brain Tumor Registry of the United States; CDC = Centers for Disease Control and Prevention; ICD-O-3 = International Coding of Diseases for Oncology, 3rd Edition; IR = incidence rate; IRR = IR ratio; NCI = National Cancer Institute; NPCR; NPCR = National Program of Cancer Registries; SEER; SEER = Surveillance Epidemiology and End Results; incidence; oncology; spinal schwannoma; spinal tumor.