Summary: BC Cancer Agency researchers used 25 years of data about cancer patients to learn where screening, diagnosis and treatments are improving cancer survival and where we've got to do better

VANCOUVER - There's good and bad news in a new report compiled by cancer researchers at the BC Cancer Agency that reviews 25 years of data about cancer patients in British Columbia. The study compares cancer statistics of major cancer sites from 1973 to 1997. Among the researchers findings, rates for lung cancer in elderly women have quadrupled, the overall death rate from cervical cancer has dropped by 60 per cent and the overall cancer death rate in the young has declined by nearly 40 per cent.

As well as the rise in lung cancer in elderly women, researchers saw the greatest increase in incidence rates in Non-Hodgkin's Lymphoma, melanoma and testicular, liver, prostate and breast cancers. Higher incidence in the last two are partly due to increasing access and improvements in screening methods.

Cancer researchers used 1973 as the reference point for measuring percentage changes in order to provide a long-range view over 25 years.

"Our goal was to get a 'big picture' of how well our cancer control measures are working," says Dr. Andy Coldman, head of Cancer Control Strategy at the BC Cancer Agency, "and to see what challenges are ahead so we can plan for them. The approach was more sophisticated than yearly reports, in order to convey percentage increases over a quarter century."

BC Cancer Agency's researchers looked at age-standardized rates* to create sex-, year-, and age-specific rates** for the young (0-44), middle aged (45-64), and elderly (65+), and for all ages combined.

The BC Cancer Registry has been monitoring the impact of cancer on the population since 1969. The registry provides crucial information for BC Cancer Agency's population-based cancer control strategies and treatment policies.

"B.C.'s mortality rate is about 11 per cent lower than the national average, even though we have one of the highest incidence rates in Canada," says Don Carlow, BC Cancer Agency's president and CEO. "We serve the people of B.C., by using resources wisely, by making recommendations to the government for increased services and programs where they are needed," Carlow says. "This 25-year trend report will help us to determine where we must improve our cancer control strategies."

Canadian Cancer Statistics 1999 - published by the National Cancer Institute of Canada, Statistics Canada, Health Canada and the provincial and territorial cancer registries - states British Columbians have lower rates of mortality due to cancer than other Canadians. The BC Cancer Agency's report on 25-year trends in cancer builds on this information by providing a more complete story of what's happening in B.C.

Highlights of 25-year trends in B.C. 

• INCIDENCE RATES: Overall, cancer incidence rates have been constant or increased slightly, most in the elderly (25 per cent) and least in the young (5 per cent). Prostate cancer has had the largest effect on the trend in male cancer rates while lung cancer has had the largest effect on female cancer rates. 
• MORTALITY RATES: Overall, cancer mortality has been constant or declined, with the best news found in the young, where mortality has fallen by almost 40 per cent. 
• BREAST CANCER: Incidence rates in elderly women had increased almost 50 per cent by 1991, but has since dropped slightly. In the young, we see declines in incidence (10 per cent) and mortality (15 per cent). In the 45-to-64 age group, incidence rates have increased by 10 per cent, perhaps due to screening programs, but the death rate has declined by about 35 per cent since 1973. The changes in this latter group are partly due to the increased use of screening mammography. 
• CANCER OF THE CERVIX: In the young and middle aged, incidence and mortality rates fell by about 50 per cent between 1973 to 1985 and have been fairly stable ever since. In elderly women, there has been a steady decline in incidence and mortality rates - indeed, a 70-per-cent drop in the latter since '73. This is largely due to the identification and removal of premalignant disease, the result of PAP smears. 
• CHILDHOOD CANCERS (up to 16 years): The incidence rate has been constant. But the mortality rate has declined by 70 to 80 per cent in boys for the three most frequently diagnosed childhood cancers: brain; lymphoma; and leukemia. In girls, the death rate has fallen by about 40 per cent for brain cancer and by about 70 per cent for lymphoma and leukemia. Evidently, improved treatment is responsible. 
• COLORECTAL CANCER: The mortality rate has fallen about 40 to 50 per cent for all age groups. 
• GASTROINTESTINAL CANCERS: Stomach, small intestine, colon, rectum, liver, gallbladder, and pancreas - the overall incidence rate has declined slightly. The mortality rate has declined by about 40 per cent in the middle aged and elderly and by about 50 per cent in the young. But liver cancer bucks the trend. (See below.) 
• HODGKIN'S DISEASE: This disease is a treatment success story. Incidence rates have changed little since 1973, but mortality rates have fallen by 80 to 90 per cent and are still dropping. 
• LIVER CANCER: Incidence and mortality rates for this cancer have doubled for males and risen by about 50 per cent for females. Increases may be due to the changing mix of the population, as liver cancer is rare in Caucasians and more common in Asians. 
• LUNG CANCER: For middle-aged and elderly men, incidence and mortality rates peaked in the mid-'80s and have since dropped to 1973 levels or lower. In young males, rates have declined by about 40 per cent. In elderly women incidence and mortality rates have increased by almost 400 per cent since '73. For middle-aged women, rates peaked in 1992. 
• MELANOMA (a skin cancer): In middle-aged and elderly men incidence rates have increased by 300 to 400 per cent and appear to be rising still. However, incidence rates in young males have declined slightly since a high of roughly 200 per cent in 1985. Mortality rates have increased by about 40 per cent in middle-aged men and 100 per cent in elderly men. In females, incidence rates seem to have peaked at about 200 per cent in the mid-'80s and to have declined slightly since. 
• NON-HODGKIN'S LYMPHOMA: Incidence rates have increased more in males than females, with increases close to 80 per cent for all ages. A similar increase is apparent in mortality rates in elderly men, yet far less in middle-aged men. In elderly women, incidence and mortality rates have risen by roughly 80 per cent, yet less so in the other age groups. Mortality rates in middle-aged women seem to be leveling off at about 135 per cent of the '73 rate. 
• PROSTATE CANCER: This cancer has the highest incidence rate and the second highest mortality rate of all cancer types in men. Incidence rates have greatly increased - largely due to increasing use of TUPR surgical procedures and PSA testing - and seem to have peaked around 1993 and fallen since then, except in middle-aged men. Mortality rates have increased marginally. 
• RECTAL CANCER: Incidence rates have remained constant in both sexes while mortality has decreased by about 65 per cent for all ages, presumably due to improved treatment. 
• STOMACH CANCER: Rates for this cancer have declined in both sexes and all ages by roughly 50 per cent for incidence and 60 per cent for mortality. Researchers believe the declines are due to decreasing consumption of salted meats. 
• TESTICULAR CANCER: Incidence rates have increased by about 80 per cent since '73, whereas mortality rates have decreased by about the same amount. The cause of the increased incidence is unknown, but the drop in the death rate is due to treatment advances.

*Age-standardization is a way of combining age-specific rates for different ages to ensure trends over time reflect disease patterns rather than aging patterns in the population.
**Age-specific rates are calculated as the number of new cases or deaths for a given age, sex and year, divided by the corresponding number of people in the population.

Future strategies for cancer control

Several B.C. Cancer Agency initiatives have helped lower the mortality rate from cancer in B.C. including evidence-based treatment policies that are consistently applied to all patients, and screening programs for breast and cervical cancer that have been models for programs around the world.

In order to save more lives, the BC Cancer Agency is working on further initiatives to... 

• double recruitment for screening women at risk for breast cancer; 
• begin a pilot study for a colorectal screening program; 
• develop and test a new approach to lung cancer, using B.C.-made methods for screening, early detection and treatments; 
• increase access to brachytherapy for the treatment of prostate cancer; 
• improve access to radiation therapy services across the province; 
• build a provincial surgical oncology program; 
• develop new, more targeted therapies; 
• enhance enrollment in clinical trials; 
• improve standardization of treatments across B.C.; 
• expand screening for hereditary breast cancer and test similar services for prostate and gastro-intestinal cancers; 
• promote the development of a provincial and national human resource plan, particularly for medical and radiation oncology; 
• expand tumour site specific research for leukemia and lymphoma and cancers of the breast, lung, prostate, colorectal, skin and many other types; and 
• advance investigations into the genetic root of cancer through the Genome Sequence Centre.

The BC Cancer Agency provides a comprehensive cancer control program for the people of British Columbia by working with community partners to deliver a range of oncology services, including prevention, early detection, diagnosis and treatment, research, education, supportive care, rehabilitation and palliative care. The BC Cancer Research Centre conducts research into the causes and cures for cancer. The BC Cancer Foundation has a mandate to raise funds to support the work of the Agency and Research Centre, for a world without fear of cancer.

For more information or a copy of the report, please call Francine Gaudet:
Ph: 604.877.6107
Fax: 604.877.6146
Public Relations.