A case-control study of brain tumor was conducted in collaborating hospitals in 
Boston, Providence, and Baltimore. Cases were 160 consecutive patients being 
treated for glioblastoma, grade 3 or 4 astrocytoma, or anaplastic astrocytoma. 
Controls were 128 healthy persons identified among the case's friends. A complex 
self-administered questionnaire was used to assess exposure to factors of 
interest. There was some evidence that glioblastoma is associated with a 
decreased susceptibility to allergies, a finding that may call attention to the 
involvement of immunologic disturbances in brain tumors. Our data are not 
supportive of previous reports of an association between brain tumors and 
exposure to pets or farm environment, family history of CNS malignancies or 
other neurologic conditions, or irradiation to the head. We did not find any 
evidence for an association with life-style characteristics such as cigarette 
smoking, alcohol consumption, use of drugs of any kind, or dietary intake of 
cured or smoked meat or fish.