A Backgrounder On Breast Cancer

The disease strikes one out of nine Canadian women—one of the worst rates in the world

MARK NICHOLS July 11 1994

A Backgrounder On Breast Cancer

The disease strikes one out of nine Canadian women—one of the worst rates in the world

MARK NICHOLS July 11 1994

A Backgrounder On Breast Cancer


The disease strikes one out of nine Canadian women—one of the worst rates in the world



Breast cancer, like other kinds of cancer, is caused by the uncontrolled growth of abnormal cells. There are more than a dozen kinds of breast cancer, including infiltrating ductal carcinoma—a common form that begins in the breast ducts—and lobular carcinoma, which origi-

nates in the milk-producing glands. Some breast tumors can double in size in 30 days; others take decades to develop. In its early stages, the cancer is usually confined to the breast itself. As the disease advances, breast cancer cells may collect in the underarm lymph nodes. From there, the cancer can spread, or metastasize, to other parts of the body, most commonly the lungs,


Women should watch for: a lump or thickening in the breast; discharges of fluid from the nipple; development of an inverted nipple or changes in the nipple’s color or texture; swelling or dimpling of the breast; changes in size, contour or shape of the breast; the appearance of prominent veins on the breast’s surface. They should report any noticeable change to a doctor. The best ways to check for breast cancer include:

Regular breast self-examination. Most breast cancers are discovered by women themselves. The best time for premenopausal women to examine their breasts is after the end of a menstrual period.

Annual breast examinations by a physician or other trained health-care professional.

Routine mammograms (breast X-rays) after the age of 50.

liver, bones or brain. In recent years, however, doctors have learned that even early cancers can spread rapidly, and they have begun to view breast cancer as a systemic disease that affects the whole body. Breast cancer mainly affects women over the age of 50. While the disease is less common among women under 40, when they do get it the cancer tends to be more aggressive.


The majority of breast cancers occur in women with no known risk factors. But some characteristics point to a higher than normal risk. They include: being 50 or older; a previous bout with breast cancer; having relatives who had breast cancer; being overweight; beginning menstruation before the age of 12; long-term use of estrogenbased birth control pills; not having children or having a first child after the age of 30. Living in North America appears to be a risk factor in itself—perhaps, some researchers say, because of the typical high-fat diet, or other lifestyle or environmental factors.


There are four main ways of treating breast cancer:

Surgery, including mastectomy—removal of the entire breast—and partial mastectomy or lumpectomy, in which only the tumor and immediate surrounding tissue are removed. Combined with radiation, a lumpectomy is now considered as effective as mastectomy in treating many early tumors. In

both mastectomies and lumpectomies, surgeons usually remove some lymph nodes from the adjacent armpit area to see if the cancer has spread.

Following surgery, radiation directed at the breast area can reduce the chance of a local recurrence by weakening and

killing any remaining cancer cells. Typical treatment following lumpectomy could include daily sessions lasting a few minutes, five times a week, for about five weeks. Side-effects include fatigue and skin irritation.

Chemotherapy involves the use of powerful toxic drugs to

kill cancer cells throughout the body. The drugs can also harm healthy tissue, resulting in such side-effects as nausea and hair loss. Chemotherapy is administered orally or by injection into a muscle or vein. Treatment may last from weeks to months, depending on the type of cancer and general health of the patient.

Hormone therapy is based on the fact that certain types of breast cancer use the hormone estrogen to grow. Hormone therapy interrupts the flow of estrogen to starve and kill the tumor. Tamoxifen is the main anti-estrogen drug often used to prevent or treat a recurrence of breast cancer.


Women’s reactions to the loss of a breast vary widely. Some are content to live with one breast or at least unwilling to undergo further surgery; they may use a prosthesis, or removable form, under their clothing. Women seeking a permanent replacement now have options. The breast can be reconstructed using the woman’s own tissue. As well, implants made of silicone or other materials can be inserted in the breast area, although silicone breast implants have been blamed for a variety of illnesses.


Survival rates for breast cancer are higher than those for most other cancers. The overall five-year survival rate for women diagnosed with breast cancer is 74 per cent, compared with 40 per cent for ovarian cancer and 14 per cent for lung cancer. But for women who have had breast cancer, the chance of a recurrence is always there. In fact, most doctors now consider breast cancer to be a chronic disease.


About one per cent of all breast cancers are in men. Although such tumors are much easier to spot than in women, many men are unaware that they can get breast cancer and, as a result, ignore warning signs and delay seeing a doctor. □

The Statistics

One out of nine Canadian women will develop breast cancer during her lifetime. That gives Canada the second-highest rate of breast cancer in the world, topped only by the United States. Canada’s 10 most frequently occurring cancers, estimated for 1994:

TYPE OF CANCER NEW CASES DEATHS FIVE-YEAR SURVIVAL RATE Lung 19,600 16,600 14% Breast (female) 17,000 5,400 74 Colon/rectal 16,300 6,300 54 Prostate 14,300 4,100 62 Lymphoma 7,100 3,350 50 Bladder 4,800 1,350 72 Kidney 3,700 1,350 51 Leukemia 3,200 2,040 37 Oral 3,120 1,110 54 Melanoma 3,100 580 81 SOURCE: STATISTICS CANADA. * BASED ON LATEST AVAILABLE DATA FROM BRITISH COLUMBIA, SASKATCHEWAN AND ONTARIO.

When cells run amok