Breast cancer incidence and mortality rates vary between the provinces
and territories (Figure 1). The highest estimated incidence rate
in 1999 was in Manitoba with Quebec having the lowest. Lung cancer
incidence and mortality rate estimates for women are shown for comparison
purposes.
[D] Click for larger version, 13 KB Figure 1. Provincial Breast and Lung Cancer Incidence and Mortality Rates, 1999
It is important to note that the numbers shown in this chart are
estimates. Estimates are produced by the National Cancer Institute
of Canada (1999) in order to assist with prevention and treatment
program planning. Actual incidence and mortality rates usually differ
little from estimates today because of the improved monitoring programs
of the National Cancer Institute of Canada. However, the numbers
shown should be used with caution especially when comparing provincial/territorial
rates because these jurisdictions do have slightly different disease
registration procedures.
The two maps of breast cancer incidence were derived from actual
incidence values, not estimates. Both illustrate age-standardized
incidence for the period 1986 to 1995 and should be read together
as much as possible. The first shows age-standardized rates while
the second is of classes of age-standardized ratios. (refer to:
Standardization
of Rates: A Methodological Note).
Perhaps the most striking spatial pattern that is shown on these
maps is the statistically low incidence of breast cancer in Newfoundland
and Labrador, the territories, and northern areas of most provinces.
Otherwise, each province has one or more pockets of significantly
high breast cancer incidence. These are often located in more southerly
areas, but they do not seem to be restricted to either urban or
rural areas alone.
The highest 1986 to 1995 breast cancer rates can be found in south-central
and southern Manitoba where the age-standardized rates per 100 000
exceed 120. A similarly high rate can be found in Shelburne County,
in southwestern Nova Scotia. Additional clusters of relatively high
breast cancer incidence rates are located in southern Alberta and
British Columbia. In Ontario, the highest rates can be found in
the southwestern part of the province and in the Ottawa area.
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