Shechar Dworski, BSc

Lung cancer is the most common cause of cancer-related deaths in both men and women, accounting for 34% of cancer-related deaths in men, and 22% in women. Lung cancer survival rates are dismal: the five-year survival rate is 14% for all cases of lung cancer, and the median survival is less than half a year for untreated patients. The lung cancer mortality rate in the United States is approximately 50 in 100,000, 68% of which occur in people over 65 years of age. Lung cancer mortality in the elderly is rising, which may be due to the aging of the population. Between 1968 and 1983, there was an 8.2% annual growth in mortality in white women 54 to 74 years old. The mortality rates in males seemed to reach a plateau in the 1980's, or may even be declining, possibly due to a decrease in the cigarette smoking by men from 67% in the 1950's, to 28% presently in the United States.

Over one half of all cases of lung cancer are reported in people aged 65 and over. Men aged 65 years and over have an incidence of lung cancer three times higher than men age 45 to 64. This trend is thought to be related to increased lifetime exposure to tobacco smoke and other carcinogens. The rate of lung cancer has risen dramatically in the last 70 years, accounting for 18% of all cancer cases in men, and 12% in women.

Sheldon Singh, BSc

Colorectal cancer is the second leading cause of cancer death in North America and Western Europe. This disease tends to occur mainly in older individuals. Early-stage disease is curable in more than 80% of patients. Unfortunately, more than 55% of patients present late with evidence of lymphatic or distant metastases. There is now compelling evidence that screening of average risk individuals over 50 can identify disease at a more curable stage thereby allowing for more effective management and subsequent reduction in mortality.

Epidemiology
Cancer of the colon and rectum kills more Canadians than any other cancer with the exception of lung cancer. During their lifetime, women have a 1 in 18 chance of developing colorectal cancer while men a 1 in 16 chance. This year, the disease is expected to affect 16,600 Canadians (with roughly 93% occurring in people over age 50) and claim 6,300 lives (with roughly 95% occurring after age 50). Rates of colorectal cancer in Canada have been declining, particularly among women. This may be due to changes in diet as well as the casual use of screening techniques.

Risk Factors
Age is a major risk factor for developing colorectal cancer. Approximately 75% of colorectal cancers are sporadic and without any identifiable risk factors other than age. Colorectal cancers are rare before 50 and over 90% are diagnosed after 60.

Rhonda Witte, BSc

Cancer. The word alone is enough to send fear into the hearts of people. It is safe to assume that everyone knows of someone who has been touched by cancer; they know of someone who is living with or has died of the disease. There are also people who have triumphed over the disease--they have fought cancer and won, they are survivors. Over the years, there have been numerous advances in cancer research. A hot topic in cancer research, in recent years, has focused around a process called angiogenesis. Specifically, researchers are trying to understand angiogenesis and use this knowledge to prevent the growth and spread of cancer.

Angiogenesis, also called neovascularization, is the growth of new blood vessels. Normally, the endothelial cells comprising the capillary walls do not divide. However, during pregnancy, menstruation, and wound repair, endothelial cells are stimulated to grow and divide, increasing the number of blood vessels.^1-3 During angiogenesis, endothelial cells must break through the basal lamina around the capillary wall. They do this by releasing proteases, thereby degrading the extracellular matrix. Endothelial cells then migrate toward the stimulatory signal, proliferating and aligning to form new capillaries.⁴ When properly regulated, angiogenesis stops after a short period of time.

Michel Silberfeld, MD, MSc, CRCP(C)

Coordinator, Competency Clinic, Department of Psychiatry
Baycrest Centre for Geriatric Care. North York, Ontario

In Ontario, as in some other provinces, there was a push to modernize guardianship and consent legislation, which culminated in new statutes in 1992. The motivations for new legislation came from several directions. The Ontario Mental Incompetency Act was felt to be outdated because it only permitted plenary guardianship. Plenary guardianship gives a person authority over all decision-making, much like a parent has over a small child. Furthermore, incapacity was poorly defined, based primarily on evidence as to the severity of an illness, and a person deemed incapable had to be incapable in all respects. There were no provisions for Powers of Attorney for personal care.

Several policy initiatives came from patient rights advocates. There was a desire to promote patient autonomy. This was accomplished by clarifying the definitions of capacity in statutes. The new definitions permitted the recognition of partial competence whereby a person could be incapable in one respect and yet retain the right of discretion in all others.

The article "SPECT May Help Resolve Dementia Diagnosis," in the January/February issue fails to mention EEG in diagnosis of dementia, a test cheaper than SPECT and CT. EEG is quite sensitive, correlates with prognosis, and is specific withing a given clinical context.

Your title "May Help Resolve" may generate unnecessary referrals for SPECT scanning in this situation. At a time of rigorous health care funding, we need to utilise only those tests which are clearly going to benefit the patient in a cost-effective manner. This article does not advance that goal.

Sincerely,

Warren T. Blume, MD, FRCPC,
Professor,
Department of Clinical Neurological Sciences,
Epilepsy and Clinical Neurological Sciences,
London Health Sciences Centre,
London, Ontario

P.S. The cost of EEG versus SPECT scanning is $51.20 and $162.50 respectively.

Use of oral contraceptives may lower the risk of hip fracture later in reproductive life, according to a report in the May 1st issue of the Lancet. Previous studies have shown a protective effect of postmenopausal oestrogen therapy on the risk of having a fracture. However, whether or not oral contraceptives, which also contain the hormone oestrogen, can confer a similar risk is not clear.

Dr Karl Michaëlsson and colleagues, from Sweden and the USA, collected data on all cases of hip fracture that occurred between October 1993, and February 1995, among women in Sweden. Questionnaires were then posted to these women who had had a hip fracture (the cases), and to a group of women who had not had a hip fracture (the control group) to ascertain details about the women's previous use of oral contraceptives.

Of the 1327 cases, 130 (11.6%) had used oral contraceptives. Of the 3312 controls, 562 (19.1%) reported previous use of oral contraceptives. The use of oral contraceptives was associated with a 25% reduction in risk of having a hip fracture later in life. Women who had previously taken an oral contraceptive containing a high dose of oestrogen had a 44% reduced risk of hip fracture.

Oestrogen in the oral contraceptive pill acts on bone, via a mechanism that is as yet unclear, making bones denser and stronger. After a woman has gone through menopause, her bone mass decreases naturally. The researchers postulatee that by increasing the bone mass before menopause, the mass will decrease by less overall, and state that oral contraceptive users appear to reach the menopause with a bone density 2 to 3% higher than that of non-users.

*Provided by The Lancet.

Contact: Dr Karl Michaëlsson, University Hospital, S 75185 Uppsala, Sweden
tel +46 18 663000; fax +46 18 509427; e-mail: Karl.Michaelsson@ortopedi.uu.se

Valerie Ha, BSc

In the past ten years, public campaigning on behalf of breast cancer has raised awareness to new heights. Despite an increase in the incidence of breast cancer over the past twenty years (most likely due to better detection of disease), we have seen a plateau and even more recently a decline in the mortality rates in both Canada and the United States. This is likely due to our ability to diagnose disease earlier through breast screening and our improvements in treatment.

Breast Screening is indeed a major player in our fight against breast cancer. It is estimated that a significant reduction in breast cancer mortality can be achieved in Ontario if 70% of women between the ages of 50-69 were to participate in a program of early detection.

Breast cancer screening involves participation in biennial mammograms, monthly self-examination and regular breast examination by a trained professional; a regimen that should be followed during the years that the woman is most likely to be affected.

Shechar Dworski, BSc

Osteoarthritis (OA) is common in the elderly, affecting as many as 80% of people aged 55 and over. It is the most common form of arthritis, occurring mostly, but not exclusively, in the elderly. It is also the most common musculoskeletal disease in the elderly. It affects mostly the hands, as well as the major weight bearing joints of the body which are primarily the hips and knees. Please refer to the article on Osteoarthritis: Early Diagnosis Improves Prognosis in the May/June 1999 issue of Geriatrics & Aging for more information on the symptoms and specific aspects of OA. There are several routes one may take to treat OA, as well as many preventive measures. Joint replacement is usually the last step, when all other treatments have been unsuccessful. At this stage of disease, people often have difficulty walking and climbing stairs, and have joint pain at rest and at night. In this case, joint replacement therapy is extremely effective at relieving pain and improving function.