Canadian Cancer Statistics 2007: Breast Cancer Death Rate Dropping
11 April 2007
The breast cancer death rate is declining significantly and more women are surviving longer, according to a special report in Canadian Cancer Statistics 2007, released today by the Canadian Cancer Society.
The declining death rate is due to more and better screening, as well as more effective treatments.
“While these strides are good news, breast cancer continues to take a significant toll,” says Heather Logan, Director, Cancer Control Policy, Canadian Cancer Society. “We chose to study breast cancer more intensely this year because it’s the most common cancer among Canadian women, as well as globally. We must continue to make inroads against this devastating disease that affects so many women and their families.”
According to the special report, the age-standardized death rate for breast cancer for Canadian women has fallen 25 per cent since 1986. The five-year relative survival rate is 86 per cent (for women diagnosed between 1996-1998), excluding Quebec.
Better quality mammography and increased participation in organized breast screening programs (by women aged 50-69 in particular) have led to more breast cancers being detected earlier, which means successful treatment is more likely.
“We know breast cancer screening works,” says Paul Lapierre, Group Director, Public Affairs and Cancer Control, Canadian Cancer Society. “Barriers to screening must continue to be identified and overcome. If more women are screened, more will survive.”
Advances in breast cancer treatment have also contributed to improved breast cancer survival, including:
- increasing use of chemotherapy and tamoxifen;
- more use of targeted therapy in patients whose cancers over-express the HER-2 oncogene.
Breast cancer incidence rate
For Canadian women, the overall breast cancer incidence rate increased between 1969 and 1999 (by one per cent per year), but since then has been stable. Reasons for the increase are not entirely known, but may be due to a number of factors, including:
- Increased participation in breast screening programs, which results in detecting small tumors that were not yet diagnosable clinically;
- Changing patterns of childbearing and use of hormones. For example: more women are having their first child later, and older age at first birth increases breast cancer risk; use of birth control pills and combined hormone replacement therapy slightly increases breast cancer risk.
Factors that are known to influence the risk of getting breast cancer include a mixture of:
- lifestyle behaviours (obesity, physical inactivity, drinking alcohol);
- heredity factors: family history of breast cancer, having mutated BRCA1 or BRCA2 genes;
- reproductive/hormonal factors (older age at first birth, starting menstruation early, irregular periods, late menopause, using birth control pills, taking combined hormone replacement therapy).
“It’s encouraging to see the overall incidence rate for this disease beginning to stabilize,” says Loraine Marrett, Chair of the Statistics Steering Committee and an epidemiologist. “The breast cancer incidence rate in Canadais among the highest in the world. We need further information about modifiable risk factors so more can be done to prevent this disease. We want to see the breast cancer incidence rate drop as much as possible so women and their families won’t have to fear this disease.”
“Prevention of breast cancer, and all cancers, is our ultimate hope and goal,” says Logan. “To make gains in preventing breast cancer two things need to happen. First, policies are needed to protect the health of Canadians. For example, eliminating or reducing exposure to cancer-causing substances in our environment, or ensuring school programs include physical activity. Secondly, we need more information about healthy lifestyles so women can take control of their health and reduce their risk of cancer. This combination of individual action and health-first policies will have the most impact on reducing the toll cancer takes, including breast cancer.”
Based on current knowledge, opportunities for women to reduce breast cancer risk include eating a healthy diet, being physically active, maintaining a healthy body weight, minimizing alcohol consumption and avoiding nonessential hormones.
The breast cancer special report identifies four key ways to ensure progress continues against this disease so that fewer women are diagnosed with the disease and fewer die from it:
- Through research identify additional modifiable risk factors for breast cancer, such as occupational and environmental exposure, and vitamin D;
- Increase research to identify further genetic factors so that women at high risk can take appropriate actions;
- Increase participation in organized breast screening programs among women aged 50-69 by developing more effective methods for recruitment and retention;
- Continue to use the best treatment options, and develop and test new treatments.
“The Canadian Cancer Society supports these recommendations,” says Lapierre. “We need to build on the knowledge we have now, so we can find out more about preventing breast cancer and, ultimately, save more lives.”
“Canada’s New Government recognizes the importance of prevention and early detection in saving lives from cancer,” says the Honourable Tony Clement, Minister of Health. “That is why we invested $260 million in the Canadian Strategy for Cancer Control and $300 million for the implementation of a human papillomavirus vaccine immunization program to help protect women and girls from cancer of the cervix. Initiatives such as these will help reduce the number of new cases of cancer among Canadians, enhance the quality of life of those living with cancer, and lessen the likelihood of Canadians dying from cancer.”
General cancer trends
Canadian Cancer Statistics 2007 reports that:
- In general, age-standardized incidence and death rates for the majority of cancer sites have stabilized or declined during the past decade.
- Death rates have declined for all cancers combined and for most types of cancer in both men and women since 1994. Exceptions are lung cancer in women and liver cancer in men.
- Despite largely stable or declining age-standardized rates, the total number of new cancer cases and deaths continue to rise steadily as the Canadian population grows and ages.
Probability of developing/dying from cancer
- An estimated 39 per cent of Canadian females and 44 per cent of males will develop cancer during their lifetimes.
- An estimated 24 per cent of women and 28 per cent of men will die from cancer, or approximately one out of every four Canadians will die from cancer.
Canadian Cancer Statistics 2007 is prepared, printed and distributed through a collaboration of the Canadian Cancer Society, the Public Health Agency of Canada, the National Cancer Institute of Canada, Statistics Canada, provincial/territorial cancer registries, as well as university-based and provincial/territorial cancer agency-based cancer researchers.
Five-year relative survival is the proportion of people alive five years after their diagnosis, adjusted for the deaths expected for people of the same age in the general population. Relative survival is the most often used method for analyzing the survival of cancer patients across a population.
Survival is calculated from the date of diagnosis to five years after diagnosis. In Quebec the date of diagnosis is determined differently than other provinces and, as a result, Quebec survival cannot be compared with survival data from other provinces.
Age-standardized rates refer to the number of people per 100,000 who are diagnosed, or die of, cancer. Age-standardization allows comparisons among the different years since it accounts for changes that have occurred over time in the age distribution of the population.
The Canadian Cancer Society is a national community-based organization of volunteers whose mission is the eradication of cancer and the enhancement of the quality of life of people living with cancer. When you want to know more about cancer, visit our website www.cancer.ca or call our toll-free, bilingual Cancer Information Service at 1 888 939-3333.