Breast Cancer

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Breast Cancer

About the disease

Breast cancer is the most commonly diagnosed cancer in women, and accounts for 30 per cent of all cancers. One in eight women will develop breast cancer in her lifetime and the lifetime probability of dying of breast cancer is one in 29. Most breast cancers occur in women over 50. Although it is less common, men can also develop breast cancer (about 1 per cent of all breast cancer cases).

In Alberta in 2003, 1,794 women and 13 men were diagnosed with breast cancer. In the same time period, 420 women and three men died of their disease.* According to the National Cancer Institute of Canada, it’s estimated that 23.4 women per 100,000 will die of breast cancer in 2006. In 1977, the number was 30.6 per 100,000.**

*Alberta Cancer Board, Cancer in Alberta: A Regional Picture 2006
**Canadian Cancer Statistics, 2006 p. 43

Risk factors

Risk factors are determined by analyzing the numbers of patients with cancer in a large population sample and trying to find differences in the characteristics or behaviors between those who develop cancer and those who do not. The Alberta Cancer Board’s Tomorrow Project, for instance, is tracking more than 50,000 Albertans over a 50-year period to learn more about who develops cancer and why.

The vast majority of breast cancer patients have no identifiable risk factor. A hereditary genetic link is found in only five to 10 per cent of women who develop breast cancer. Age remains the most common risk factor.

Other factors that may increase the risk of developing breast cancer include:
female gender
age
personal history of previous breast cancer,
family history
hormone exposure
no prior pregnancies
increasing age at the time of first birth,
late menopause or early age of first menstrual period
hormone replacement therapy
history of prior breast problems requiring a biopsy
genetic predisposition
more controversial risk factors include - obesity, prior low-dose radiation, and oral contraceptive use.
Factors that may decrease the risk of developing breast cancer include:

regular exercise
maintaining a healthy body weight
pregnancy at a younger age
breast feeding
early menopause or late age of first menstrual period

Genetic links

Hereditary breast cancer makes up five to 10 per cent of all cancers. A blood test (BRCA genetic testing) can be used to detect the presence of genes that indicate an increased susceptibility for development of breast cancer. Certain criteria and a referral for genetics counseling are required to proceed with these investigations.

Cancer Research UK, Definite Breast Cancer Risks
The Tomorrow Project

Symptoms raising suspicion of breast cancer

Painless lump in the breast or armpit region, thickened or dimpled skin or nipple retraction.

Other changes to the breast, such as unusual bruising, excessive warmth, swelling or redness may signal the much rarer form of breast cancer (inflammatory breast cancer).

Metastatic breast cancer (late stage disease) can present with symptoms depending on the site of the specific organ involved.

Detection and diagnosis

Any woman who discovers a lump or other changes to the breast should visit her family physician. Breast imaging (such as mammogram / ultrasound), possibly with a biopsy, may be arranged.

Mammograms

Routine breast cancer screening with mammography can reduce breast cancer deaths by 30 per cent in the population of women over 50. Women between 50 and 69 years of age are advised to have a mammogram at least every two years. Mammography is free. You do not need a doctor’s referral to access mammograms. The test can be arranged through any radiology clinic or province wide, under the Alberta Cancer Board’s Screen Test Program. Women under 50 should speak to their health care provider about the need for a mammogram.

Alberta is also in the process of launching a province-wide screening program, which will help remind women and their health care providers when it is time for a mammogram. Visit the Alberta Breast Cancer Screening Progam to learn more about who should be screened, how often, and many breast cancer facts.

Biopsy

Based on information obtained from a mammogram, your physician may arrange for a follow-up biopsy. These may require a needle or small incision to remove part of a lump, suspicious tissue or fluid.


Estrogen (ER) and Progesterone receptor (PR) test

This test establishes a breast cancer’s potential sensitivity to female hormones (e.g.estrogen and progesterone). If a tumour is estrogen receptor positive it is more likely to respond to anti-estrogen therapies that interfere with estrogen’s encouragement to grow.

Treatment

Treatment for breast cancer will vary depending on the stage of breast cancer diagnosis.

Surgical treatment options

Lumpectomy:
Removes the breast tumor without removal of the remaining surrounding breast tissue. This should always be followed by radiotherapy.

Simple (or total) mastectomy:
Removes the entire breast without any underlying muscle removal.

Modified Radical Mastectomy:
Removes the entire breast and includes a procedure called axillary (arm pit) dissection, in which levels I and II (of three levels) of the axillary lymph nodes are also removed.

Radical mastectomy:
Removes the entire breast tissue along with some of the muscles of chest and lymph nodes on the underside of the shoulder between the upper arm and the side of the chest. This is no longer offered or done routinely.

Axillary dissection: removal of lymph nodes in the axilla (arm pit). You may or may not qualify for a “sentinel” lymph node biopsy (SLNB), depending on your specific clinical situation. SLNB is a procedure whereby the surgeon selectively removes the axillary lymph node most likely to be involved with cancer. If cancer is found within the sentinel lymph node, a full axillary dissection is usually performed, If no cancer is found within the sentinel lymph node, no other lymph nodes are removed. Please discuss with your surgeon to see whether or not you qualify for this procedure.

Breast reconstruction or prosthesis: These options do not appear to impact survival rates following original breast surgery. Options include implantation of prosthesis after mastectomy or reconstructive surgery.

Radiotherapy

Radiation (similar to X-rays) is used to target any cancer cells that may remain (locally or regionally) following breast cancer surgery. While normal cells can recover from exposure to radiation, it is hoped that the cancer cells do not. Side effects include potential changes to the skin and underlying tissue. Your radiation oncologist will discuss these more in detail.

Systemic Therapy

This is medication designed to travel throughout your body to target any remaining breast cancer cells. This type of therapy includes chemotherapy, hormonal therapy and biologic (or small molecule) therapy. Systemic therapy is tailored for each patient and their specific breast cancer traits. All therapies have potential benefits and side effects.

Chemotherapy
Chemotherapy is designed to kill rapidly dividing cancer cells. Other healthy cells in your body are also dividing and may be susceptible to these drugs as well, resulting in potential side effects. Different chemotherapies have different potential side effects. Your doctor will explain these to you.

Anti-Hormonal therapy
Some types of breast cancer are potentially “fueled” by the body’s own natural hormones, like estrogen and progesterone. A test is done on your cancer specimen to determine whether or not your tumor has receptors to these hormones.

Anti-hormonal therapy specifically targets breast cancers that express these hormonal receptors. Several types of these medications exist (oral or injection form).

Biologic (or small molecule) therapy

This is a new and emerging field of breast cancer therapy. These types of drugs (small molecules and monoclonal antibodies) specifically target breast cancer cells that are specifically susceptible to these treatments. Small molecules and monoclonal anti-bodies are at the forefront of these fields of research. Side effects can still occur, but are different than the typical chemotherapy type side effects.

Factors affecting prognosis

Stage
Pathology (e.g. estrogen and progesterone receptor levels in the tumour)
Age and general health

© 2008 Alberta Cancer Board and Foundation