Seasonal variation in the occurrence of several classes of cancer has been observed in the past. However, evidence for such trends in adult central nervous system tumors is scant. We have analyzed the monthly occurrence rates of glioblastomas as well as carcinomas metastatic to the brain in 6,154 neurosurgical patients in Toronto selected from the University Health Network neuropathologic database over a seven-year period (July 2001 to June 2008). The electronic repository was representative of the patient population in southern Ontario, and the case accession dates in the database reflected the onset patterns of the selected tumor groups. A modification to Nam's alternative method to the Roger test was developed to statistically quantify the... |