1. Preventing breast cancer
2. Links between the immune system and cancer prevention
3. Early warning signs of breast cancer
4. Role of environmental contaminants in breast cancer and how we can reduce daily exposure
5. Myths vs. realities in breast cancer information
6. Benign breast disease
7. Types of benign breast disease are there
8. Resources for patients with who are concerned about breast health

1. Preventing breast cancer

At present, there is no way to prevent breast cancer.There is no single cause of cancer, but some factors appear to increase the risk of developing it. See Breast Health Basics to learn ways to decrease the risk of breast cancer.

2. Links between the immune system and cancer prevention

Studies have not shown a consistent link between the immune system and breast cancer. Recent studies have shown that there is activation of parts of the immune system in some patients with breast cancer, including DCIS and early disease, but there are not large studies to show if this happens in all patients or what it means. It is known that the immune system is very complex and activation of one part of the immune system may or may not affect other parts of the immune system. As well, there are no immune deficient diseases that clearly are associated with an increase in breast cancer. Research is however being done and links with the immune system may be found in the future.

At this time there is no evidence that medications or other measures to boost the immune system generally are effective to treat breast cancer, but work is being done on cancer vaccines and other treatments that will use the immune system and immune stimulation. The vaccines that show the most promise are likely going to involve specific targets such as HER2.

3. Early warning signs of breast cancer

• Lump in breast found by the woman herself, through a clinical breast exam by a health care provider, or detected on a screening mammogram before it can be felt
  • Constantly present and does not come and go with the menstrual cycle
  • May feel like it is attached to the skin
  • May feel hard, irregular and different from the rest of the breast tissue
  • May be tender but not painful (pain is more often a symptom of a benign condition, but should be checked by a doctor)
• Lump in the armpit
  • Enlarged lymph node – usually means that the lymphatic system is fighting an infection in that area
  • Sometimes means that breast cancer has spread to the lymph nodes
• Inverted nipple
  • Some nipples are always inverted
  • Nipples that become inverted should be checked by your doctor
• Crusting, ulceration or eczema-type symptoms on the nipple
  • May be a sign of Paget's disease
• Nipple discharge
  • Has many different causes and should always be reported to a doctor
  • May be a sign of cancer if it occurs spontaneously (without squeezing) and is blood-stained
• Changes in breast size and shape
  • A change in the outline of the breast
  • A change in the size of the breast
• Changes in the skin of the breast
  • Dimpling or puckering of the skin
  • Thickening and dimpling skin – like an orange peel
  • Redness, swelling and increased warmth in the affected breast
  • Ridges and wheals (round, itchy areas)
  • Distended veins on the breast in an irregular pattern ^1,2

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4. The role of environmental contaminants in breast cancer and how we can reduce daily exposure

See the Canadian Cancer Society website for information on the connection between environmental contaminates (including pesticides, electromagnetic fields, asbestos, chlorinated water, air pollution, and radiation) and cancer.

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5. Myths vs. realities in breast cancer information

• Antiperspirants and breast cancer
• Abortion and breast cancer
• Bras and breast cancer
• Food additives
• Microwaves and plastic containers
• Hair Dye
• Implants
• Birth Control Pills - "Most studies have shown no significant increased risk for breast cancer from oral contraceptive use, although there is evidence they may reduce risk for ovarian and uterine cancer. A few recent studies suggest a small increase in risk in specific subgroups of women who have mainly used older types of oral contraceptives which contained more estrogen than those commonly used today. The largest overall analysis show no significant increase in risk of breast cancer for women who take oral contraceptives when compared to women who do not take oral contraceptives."³
• Stress, emotional upsets or depression - Although many women link the onset of breast cancer to stressful life events, well-designed studies do not support this link. It is important to remember that breast cancer develops over many years and has likely been present for a long time before it is diagnosed.⁴
• Radiation - Women who have received some form of medical ionizing radiation to the breast area, especially before the age of 15, have an increased risk of breast cancer. Studies have shown that the younger a woman was when she received radiation treatment, the higher her risk for developing breast cancer later in life. The risk of breast cancer development is increased if a woman:
  • received radiation to the thorax and/or neck;
  • received radiation for postpartum mastitis
  • underwent numerous chest x-rays and radiation therapy to treat tuberculosis; or
  • was exposed to large amounts of radiation as a child before the age of 15 (e.g. for the treatment of Hodgkin's disease). A child's tissue cells are very sensitive to radiation effects. This sensitivity diminishes as the person grows older, until by the age of 40, the degree of sensitivity is very minimal⁵
• Level of risk following radiation therapy for breast cancer - Women with breast cancer who have been treated with a lumpectomy and radiotherapy do not appear to be at increased risk of a second breast cancer due to the radiation therapy. Studies have shown that there is no difference in the risk of a second breast cancer between those women treated with a lumpectomy and radiation, and those treated with surgery alone. An uncommon form of skin cancer called angiosarcoma has been reported, but the risk is only 1 in 1,000 women who survive more than ten years after initial treatment. There is conflicting evidence about whether radiation therapy for breast cancer increases the risk of other cancers but some studies have shown a very small increased risk of lung or skin cancer in women surviving ten to 20 years after treatment for breast cancer⁶
• Level of risk with screening mammography - "In a screening mammogram, x-rays are produced at a dose which minimizes the possibility of harm whilst providing a detailed image in which early cancer can be seen. The amount of radiation from a screening mammogram is about the same as three months of background radiation which corresponds to a 12% increase in radiation exposure to women being screened every two years. This may initially seem to be a significant amount, but this must be measured against the benefits of having a screening mammogram."⁷
• Hormone replacement therapy (HRT) - Recent studies have found that prolonged use of HRT (estrogen and progestin combined) increases the risk of breast cancer. In one particular study, the risk increased by almost 25% when used for five years or more after menopause. This means that if a woman's age-related risk of developing breast cancer was 4%, prolonged HRT could raise it to 5%. Prolonged use of HRT also appeared to increase the risk of heart disease, stroke and blood clots to the lungs (pulmonary embolism). These studies indicated that the risks of prolonged HRT use, in most cases, outweighed the benefits. The Canadian Cancer Society recommends women should avoid taking combination HRT for any reason other than to relieve severe menopausal symptoms that have not responded to any other treatment⁸
• Smoking - Smoking does not appear to significantly increase or decrease the risk of developing breast cancer. However, a 2002 study of B.C. women found that young women who start smoking within five years of their first menstrual period face a 70% higher risk of developing breast cancer than those who never smoke. Researchers suspect that the higher risk for young female smokers is because during puberty, the cells that make up the breast are still forming, and are therefore more susceptible to cancer causing substances. The tissues of a woman's breast don't become fully differentiated until the end of a first and full-term pregnancy.
  
  While cigarette smoke increases the risk of breast cancer among pre-menopausal women, it appears to decrease the risk for some overweight, post-menopausal women. The possible reason that smoking might inhibit breast cancer in post-menopausal women is that the chemicals in tobacco may block the production of estrogen, which has been linked to breast cancer. The decrease in breast cancer risk was evident among post-menopausal women who began smoking after their first full-term pregnancy, and had gained weight since early adulthood. However, women should be encouraged to quit smoking as there are well established health benefits to the lungs and heart for doing so⁹

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6. Benign breast disease

Benign breast disease is a term that describes a broad group of breast conditions that are not malignant. In general, benign breast disease:

• may appear as solitary or multiple breast lumps. There is no way to prevent these abnormalities from developing, but certain measures may decrease their size or discomfort they provide;
• may cause breast tenderness. Generalized fullness before a period starts is common and not a sign of any malignancy;¹⁰
• does not change into malignancy; and
• may fluctuate with the menstrual cycle, being most obvious just before menstruation begins.

Diagnosis of a single breast lump is important to ensure it does not represent a malignancy. A mammogram followed by breast ultrasound to determine if the lump is fluid-filled or solid are appropriate diagnostic measures. If the lump appears solid, an aspiration biopsy (fine needle aspiration), a core biopsy or open biopsy should be performed. Fluid-filled cysts can be aspirated with a fine needle.

7. Types of benign breast disease

The Calgary Health Region's Health Link website contains excellent information on common benign breast conditions, including breast calcifications, breast lipomas, breast pain, cellulitis of the breast, fibroadenoma, fibrocystic breast changes (FBC), mastitis, and nipple discharge.

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8. Resources for patients who are concerned about breast health

• Pesticides and your health: what you can do - a Canadian Cancer Society pamphlet
• Program on Breast Cancer and Environmental Risk Factors - a program of Cornell University in New York state. The website includes fact sheets and other learning resources on environmental risk and breast cancer

REFERENCES

1. Olivotto I, Gelmon K, McCready D, Pritchard K, Kuusk U. Intelligent patient guide to breast cancer. 4th ed. Edwards C, editor.Vancouver (BC): Intelligent Patient Guide Limited; 2006, pg.41-43.

2. Canadian Cancer Society (http://www.cancer.ca. Canada: 2006. (cited Sep 22, 2006). Available from: http://www.cancer.ca/ccs/internet/standard/0,3182,3278_10175_264799_langId-en,00.html

3. BC Cancer Agency (http://www.bccancer.bc.ca). Vancouver (BC): 2006. (cited Oct 18, 2006). Available from: http://www.bccancer.bc.ca/PPI/TypesofCancer/Breast/Etiology.htm

4. Protheroe D, Turvey, K, Horgan K, Benson E, Bowers D, House A. Stressful life events and difficulties and onset of breast cancer: case-control study. British Medical Journal (BMJ). Oct 16, 1999;319:1027-1030.

5. BC Cancer Agency (http://www.bccancer.bc.ca). Vancouver (BC): 2006. (cited Oct 18, 2006). Available from: http://www.bccancer.bc.ca/HPI/CancerManagementGuidelines/Breast/ScreeningEarlyDetection.htm

6. Olivotto I, Gelmon K, McCready D, Pritchard K, Kuusk U. Intelligent patient guide to breast cancer. 4th ed. Edwards C, editor.Vancouver (BC): Intelligent Patient Guide Limited; 2006, pg.16-17.

7. BC Cancer Agency (http://www.bccancer.bc.ca). Vancouver (BC): 2006. (cited Oct 18, 2006). Available from: http://www.bccancer.bc.ca/NR/rdonlyres/DFAB281E-025E-45F6-8539-A830BE5B5A41/17495/RadiationLevelsInformation.pdf

8. CCS: http://info.cancer.ca/E/CCE/cceexplorer.asp?tocid=10

9. Band PR, Le ND, Fang R, Deschamps M (2002). Carcinogenic and endocrine disrupting effects of cigarette smoke and risk of breast cancer. The Lancet,360, pg. 1044-1049.

10. BC Cancer Agency (http://www.bccancer.bc.ca). Vancouver (BC): 2006. (cited Oct 18, 2006). Available from: http://www.bccancer.bc.ca/PPI/TypesofCancer/Breast/Benign.htm