Descriptive epidemiology of primary cancer of the brain, cranial nerves, and cranial meninges in New Zealand, 1948-88.
We used New Zealand data on occurrence of different types of brain cancer to investigate: (i) a possible secular increase which has been seen worldwide and has generated considerable debate; (ii) possibly higher rates among Maori; and (iii) possibly higher risks related to social class and occupation. Data from the NZ Cancer Registry on the 5,684 brain cancers diagnosed among NZ residents from 1948-88 were used to study the pattern of occurrence by gender, age, race, calendar year, social class, occupation, and histology. Age-standardized brain-cancer incidence rates per 100,000 more than doubled over the 41-year period (from 2.9 to 6.9 in males and from 2.1 to 5.1 in females). A strong trend of increasing incidence with increasing social class is seen in males (Ptrend = 0.01). Among Maori, the proportion of all brain cancer that is medulloblastoma is four times that among non-Maori, and the proportion of all brain cancers that lack histologic confirmation is about 40 percent higher. Elevated risks are seen among: dairy farmers (odds ratio [OR] = 3.4, 95 percent confidence interval [CI] = 1.9-6.0); sheep handlers (OR = 2.7, CI = 1.4-5.3); livestock workers (OR = 3.8, CI = 1.7-8.4); and farm managers (OR = 3.2, CI = 1.4-7.2); as well as among electrical engineers (OR = 8.2, CI = 20-34.7); electricians (OR = 4.6, CI = 1.7-12.2); and other electrical workers. Brain cancer rates in NZ have increased steadily since 1948, but this increase has leveled off in the most recent five-year period. Although brain cancer rates are likely to be underestimated among the Maori, an excess of medulloblastoma is evident in this group.
Preston-Martin
S
S
Department of Medicine, Wellington School of Medicine, University of Otago, New Zealand.
Lewis
S
S
Winkelmann
R
R
Borman
B
B
Auld
J
J
Pearce
N
N
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000453:epidemiology* / Q000208:ethnology / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D003390:Cranial Nerve Neoplasms / Q000453:epidemiology* / Q000208:ethnology / Q000473:pathology; D005006:Ethnicity; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008527:Medulloblastoma / Q000453:epidemiology / Q000208:ethnology / Q000473:pathology; D008577:Meningeal Neoplasms / Q000453:epidemiology* / Q000208:ethnology / Q000473:pathology; D008875:Middle Aged; D009520:New Zealand / Q000453:epidemiology; D009790:Occupations; D016017:Odds Ratio; D011114:Polynesia / Q000208:ethnology; D012307:Risk Factors; D012923:Social Class