Cancer is one of the most feared diseases of our time. Depending on your sex, different organs can be affected. In North America, breast cancer is the most commonly diagnosed cancer in women and the second most lethal cancer after lung cancer. In 2009, an estimated 22,700 Canadian women were diagnosed with breast cancer, and 5,400 died from it. One in 9 women will develop breast cancer in her lifetime, and one in 28 will not survive.
Breasts are modified sweat glands that can produce milk in women. They are considered secondary sexual organs because they are not essential for reproduction. The breast tissue extends from the armpit up to the collarbone and across to the breastbone in the middle of the chest (see diagram below). Breasts rest on the chest muscles that cover the ribs and are made of glands, ducts (thin tubes), and fatty tissue.
Lobules are a group of glands that produce milk (see diagram below). From the lobules, milk travels through a network of ducts to the nipple. The nipple is in the center of a darker area of the skin (areola). Fatty tissue surrounds and protects the lobules and ducts.
Legend: 1. Chest wall 2. Pectoralis muscles 3. Lobules 4. Nipple
5. Areola 6.Duct 7. Fatty tissue 8. Skin
There are lymph vessels and lymph nodes (small bean-shaped glands) in the breasts. These vessels and nodes are part of the lymphatic system, which helps fight infection. Lymph fluid flows through the lymph vessels to the lymph nodes. The nodes trap viruses, bacteria, cancer cells, or other toxic substances. Lymph nodes are found near the breast, under the arm, near the collarbone, and behind the breastbone (chest).
Cancer is the result of cells that divide and grow uncontrollably. Breast cancer can start in the ducts (ductal carcinoma) or in the lobules (lobular carcinoma). The most common type of breast cancer is ductal carcinoma. The breast tissue is sensitive to the female hormones estrogen and progesterone—this is the reason why only 1% of breast cancers are found in males.
Scientists still do not know what causes breast cancer, but many risk factors have been identified:
• Sex: 99% of breast cancer affects women
• Age: being over 50 years old
• Family history of breast cancer
• History of abnormal breast cells
• Giving birth for the first time after age 30
• Never breastfeeding
• Dense breast tissue
• Exposure of the breast to high levels of radiation (i.e., x-ray) before the age of two
• Women after menopause who are overweight
• Early menstruation (before the age of 12)
• Late menopause (after age 55)
• Taking hormone replacement therapy
• Long-term use of birth control pills
• High alcohol consumption (more than one drink/day)
• Low physical activity
Breast cancer is often a very traumatizing disease. The good news is that cancer takes many years to develop, and lowering your risks is possible. Besides examining your breast every month, here are lesser-known lifestyle choices to avoid/limit:
• Night shifts: night workers tend to produce less melatonin, a hormone which helps
prevent some of the steps leading to cancer.
• Red meat: women should eat red meat a maximum of two times per week.
• Saturated fat/trans fat: saturated fats are solid at room temperature (i.e., animal
fat). Trans fats (created by hydrogenated oils) are found in pastries and crackers. Limit
the consumption of both types of fat.
• Soybean: soy (the fruit of soybean) mimics estrogen and stimulates the growth of
breast cancer cells. Eat a maximum of two servings per day.
Thousands of Canadian women will be diagnosed with breast cancer this year. Fortunately, effective treatment will enable the vast majority of these women to survive this disease. It takes many years to develop breast cancer, and the best course of action may be prevention by lowering your risks. Appropriate lifestyle changes could ultimately mean keeping the second most common cancer at bay.