Cancer

Breast cancer

The use of mammography has increased dramatically in North America since the mid-1980s. When coupled with improvements in the treatment of breast cancer, the increase is credited with recent declines in the number of deaths attributable to breast cancer. Between 1988 and 1998 all 10 provinces and the Yukon Territory established organized breast cancer screening programs to deliver high-quality screening mammographic examinations safely, efficiently and at a lower cost than was possible through the fee-for-service system. BC was the first province to set up a screening program. Researchers report that even though 30% more bilateral mammograms were done in 1996/97 than in 1991/92, costs increased by only 4% because of the lower cost per visit. [CMAJ 1999;160(3):337-41]

To investigate whether the breast cancer therapy in Quebec varied between smaller and larger hospitals, researchers analysed hospital data on 1,259 women with node-negative stage I or II disease. The proportion undergoing breast-conserving surgery increased with the size of the hospital (78% in smaller centres and 88% in larger ones). These data contrast sharply with those from 1991 studies in Ontario and British Columbia, where 43.8% and 67.6% of node-negative patients, respectively, underwent breast-conserving surgery. The authors report that large centres, particularly those actively involved in clinical research, rapidly adopt innovative therapies for the treatment of breast cancer. [CMAJ 1999;161(8):951-5]

In a related article, the Canadian Task Force on Preventive Health Care examined follow-up care for women who have been treated for early-stage breast cancer. Although the current practice is to increase the frequency of physician examinations and mammography screening, the task force reports there is no direct evidence that early detection of recurrent breast cancer through these methods improves survival rates. [CMAJ 1999;161(8):1001-8]

Cancer numbers higher but stable

Although changes in age and population growth have caused a steady increase in the number of deaths caused by cancer, figures from the National Cancer Institute of Canada indicate that the individual risk has remained stable since 1971. About 80% of cancer deaths involve people who are at least 60 years old. [CMAJ 1999;160(12):1691]

Cervical cancer

As part of the Canadian Women's HIV Study, 375 women with HIV infection underwent cervical cytological testing. Overall, 67.2% of the women tested positive for human papillomavirus, as did 90.6% of those with cervical squamous cell dysplasia. Women living with HIV need annual cervical cytological screening, and if their CD4 count is low, the time between screenings should be shortened to 6 months. [CMAJ 1999;160(2):185-91]

Prostate cancer

Is prostate cancer screening worth while? How expensive is prostate-specific antigen (PSA) testing? A study found that the cost is lower than previously reported. Researchers found that the cost of PSA screening in Canada during 1995 was $45 million. If all the eligible men had been screened, that cost would have leapt to $317 million - more than the cost of all prostate cancer care provided in Canada that year. The authors expect that the actual cost will rise to $66 million by 2000. Even so, they predict the cost of PSA screening will account for less than 0.15% of Canada's direct health care costs, a much smaller proportion than previously reported. [CMAJ 1999;160(1):49-57]

Why do physicians order PSA tests? In a survey of more than 200 physicians caring for patients without diagnosed prostate cancer, researchers found that 63% ordered PSA tests to screen for prostate cancer - 40% to investigate urinary symptoms and 33% to follow up a medical procedure or drug therapy. Tests for screening were initiated by the patients in 63% of cases. There appear to be important differences across specialties, with urologists and family physicians offering differing reasons for ordering a PSA test. [CMAJ 1999;160(1):70-5]

New prostate cancer therapies may provide hope. Researchers provided a glimpse into the way this disease will be treated in the future by examining experimental techniques. These include interstitial microwave thermoablation - implanting small heat sources in the prostate to destroy cancer cells locally while preserving surrounding tissues - and other emerging treatment options. They reported that the body of evidence for the effectiveness of different treatments in eliminating prostate cancer and prolonging cancer-free survival provides hope for the future. [CMAJ 1999;160(4):528-34]

Skin cancer

To coincide with Sun Awareness Week (May 17-23), a prominent dermatologist argued that a commonsense approach to avoiding long-term skin damage caused by exposure to the sun is needed. He advocated the SCHEGS mnemonic device.

• Sunscreen with an sun protective factor of at least 15
• Clothing that is sun protective (tightly woven and dark in colour)
• Hats with a wide, all-around brim
• Eyeglasses that block both UVA and UVB light
• Shade, especially between 10 am and 4 pm

Testicular germ cell cancer

Cancer registries around the world have started to record a larger number of new cases of testicular cancer. Researchers used Ontario's cancer registry to document an increase of 2% a year since 1964, and an overall jump of almost 60%. The largest increase was seen in men aged 15 to 29. That increase in incidence is apparently related to when they were born, with those born recently at increased risk. [CMAJ 1999;160(2):201-5]

A researcher explores some of the possible causes of this increase, including the presence of estrogen and estrogen-like substances in the environment. [CMAJ 1999;160(2):213-4]