In Canada, it is estimated that in 1992 115,000 new cases of cancer will be diagnosed. This total excludes 47,200 estimated new cases of non-melanoma skin cancer. The number of new cases is increasing by about 3,000 per year due partly to the aging population, improved registration, earlier detection of cancer and real increases in the incidence of some types of cancer. It is estimated that there will be 58,300 cancer deaths in 1992. By 1992, prostate cancer will have overtaken lung cancer as the leading cancer among men in the four western provinces while lung cancer is expected to exceed breast cancer as the leading cause of cancer deaths among women in some provinces, notably British Columbia. In British Columbia, the relative survival rates for most cancers improved between the periods 1970 to 1974 and 1980 to 1984. However, stomach, lung and pancreatic cancers, which have low survival rates, showed little improvement. This article is based on 1992 estimates of cancer incidence and mortality, cancer trends in Canada and relative cancer survival rates in British Columbia, found in Canadian Cancer Statistics 1992. This publication was prepared at Statistics Canada through a collaborative effort involving the Canadian Cancer Society, Health and Welfare Canada and the provincial/territorial cancer registries.
Previous studies of regional and temporal variation in U.S. breast cancer mortality rates have been confined largely to analyses of rates for white women.
Breast cancer mortality rates from 1969 through 1992 for white women and black women in four regions of the United States and for all women throughout Canada were compared to identify racial, regional, and temporal differences. Differences and trends in the rates were evaluated in view of breast cancer risk factors and relevant medical interventions.
Age-period-cohort models were fit to the data, and changes in birth cohort trends (suggesting a change in a breast cancer risk factor or protective factor) and calendar period trends (suggesting, in part, the impact of new or improved medical interventions) were examined.
Breast cancer mortality rates for white women were significantly higher in the Northeast than in any other region of the United States (two-sided t tests; P
Breast cancer was studied over a 20-year period in Inuit populations in the Circumpolar region. A total of 193 breast cancers were observed in women. The incidence increased from 28.2 per 100 000 in 1969-1973 to 34.3 per 100 000 in 1984-1988. However, the incidence is low, about half what could be expected based on the rates in Denmark, Canada and Connecticut (USA). The low incidence could be explained by the Inuit diet and other lifestyle factors. These benefits should be preserved, in particular in the young, to maintain a low breast cancer incidence.
In 1990, an estimated 104,000 new cases of cancer (excluding non-melanoma skin cancer) will be diagnosed in Canada. The estimated number of deaths due to cancer in that same year will total 54,500. Just over one in three Canadians can expect to develop some form of cancer during their lifetime, and one in four men and one in five women will die from this disease. Almost 10% of women will develop breast cancer, while close to 8% of men will develop lung cancer. In 1990, lung cancer alone is expected to account for 17,300 newly diagnosed cancers (16.6% of the total), and 14,200 cancer deaths (26% of the total). Cancer will also take its toll as the fourth leading cause of death in children. This article explores additional statistics, trends in cancer incidence and mortality since 1970, cancer survival rates, and cancer mortality by income level. This article is based on material prepared by Statistics Canada for inclusion in Canadian Cancer Statistics 1990 (1), and developed in collaboration with the Canadian Cancer Society, Health and Welfare Canada, and provincial and territorial cancer registries.
During 1991, an estimated 109,000 new cases of cancer will be diagnosed in Canada (excluding non-melanoma skin cancer). Estimated cancer deaths in 1991 will total 56,700. Excluding non- melanoma skin cancer, over one in three Canadians will develop some form of cancer during their lifetime, while one in four men and one in five women will die from this disease. These statistics are discussed, as well as cancer risk factors, cancer in children, age and sex distribution of cancer, cancer survival rates, trends in cancer incidence and mortality since 1970, smoking and lung cancer, and cancer among the Inuit and Indians.
Cancer incidence data for Circumpolar Inuit populations were developed and compiled from Greenland, Canada and Alaska from 1969 to 1988 to provide the largest possible base of data for documenting the unusual patterns of cancer previously reported for these populations. Cancer incidence and population data were transferred to the Danish Cancer Registry. Coded information from various ICD-classifications and codes for the basis of diagnosis were transformed to one format, enabling joint analysis. Standard descriptive analysis was carried out with presentation of number of cases, crude incidence rates (CR), age-standardized rates (world) (ASR), cumulative rates to age 64 years, and indirectly standardized ratios (SIR) to the populations of Connecticut (USA), Canada and Denmark. The resulting database can be used to support collaborative international research among the Inuit populations.
This article provides an overview of cancer in Canada in 1984, including an analysis of geographic patterns by province. Trends for selected sites of cancer incidence from 1970 to 1984 and cancer mortality from 1970 to 1987 are also examined. Finally, trends since 1970 in cancer incidence and mortality are examined in the context of strategies for cancer control. Because of the need to assemble cancer information from a variety of sources within each province and territory, several years elapse between cancer diagnosis and the compilation of national figures. Still, the year-to-year analysis of incidence data in this article provides valuable information of cancer trends. In recent years, considerable improvements in Canada's system of cancer registration have led to improved consistency among provinces for both age-standardized rates and mortality/incidence ratios.
This article analyses provincial and territorial patterns in incidence and mortality rates for selected cancer sites.
Cancer incidence data were obtained from the National Cancer incidence Reporting System and from the Canadian Cancer Registry. Mortality data are from the Canadian Vital Statistics Data Base.
Age-standardized incidence and mortality rates were calculated for Canada and each province/territory for men and women for major cancer sites for the 1991-1993 period.
Geographic variations in cancer incidence and mortality rates are strongly influenced by trends in the four leading cancers: lung, colorectal, prostate and breast. Cancer rates tended to be significantly high in Quebec and Nova Scotia and significantly low in the three westernmost provinces. These patterns generally reflect provincial/territorial variations in smoking prevalence, dietary habits, and the extent of cancer control programs, such as screening.
Abstract' Clear differences occurred in the cancer patterns among the population sub-groups in the NWT. When compared to those for the total Canadian population, rates for all cancers tended to be higher than expected among Inuit, lower than expected among Status Indians, and at expected levels for the Other NWT population. Among Inuit, traditional patterns still persist. Cancers of the lung, cervix, nasopharynx and salivary gland, and choriocarcinoma, occurred more often, and cancers of the breast, prostate, uterus and colon less often than in the total Canadian population. Among Status Indians, small numbers precluded definitive conclusions. However, several cancer sites occurred less often than expected, including colon, bladder and prostate among males, and uterus in females. While no cancer was significantly elevated in either males or females, SIRs for cervix and lung were above 1.0 for females, and kidney cancer was significantly higher when data for both sexes were combined (SIR = 2.0). For the Other NWT group--comprising about 50% of the population--most types of cancers occurred at about the expected rate, except that lung cancer was significantly elevated in females. Nevertheless, the generally high rates for lung and cervical cancer, which were particularly evident among the Inuit, are clearly targets for prevention programmes. It is hoped the cancer registry data now available for twenty years for the NWT, as well as for the overall Canadian Inuit population, can be used by researchers for studies to further determine the etiology of cancers, especially where distinctive patterns occur in these populations.