Although breast cancer is the most common cancer in women in the U.S., deaths from it are declining, probably due to earlier detection and treatment. There are many types of breast cancer; however, all of them need adequate treatment in order to have a good outcome.

About Breast Cancer

Breast cancer is the most common cancer in women in the United States, after skin cancer. However, because of earlier detection and more effective treatment plans, the outcome is often positive.

At this time, there are no known measures to prevent breast cancer. However, researchers continue to search out answers and hopefully reduce risk factors.

The following topics are included in this section:

Facts About Breast Cancer

Following are some facts about breast cancer:

Development of Breast Cancer

Breast cancer is a condition where breast cells become abnormal and multiply uncontrollably due to genetic alteration.

How It Starts

Genetic alterations that lead to breast cancer can occur in one of two ways. A person can inherit them from either parent, in which case the person starts life with damaged genetic code in every cell. This person is much more likely to develop breast cancer than the average person. There can be significant risks for other cancers (i.e. ovarian) associated with these types of gene mutations as well. Only about 10% of breast cancer is due to these specific inherited gene mutations (often referred to as a hereditary cancer syndrome). Families with hereditary cancer syndromes typically have multiple people affected with cancer and often, the cancers occur at earlier ages.

A person can also develop a genetic alteration later in life due to environmental factors. Some people may be more susceptible to effects of environmental factors due to genes they inherited from their mother or father. These genes do not define this person’s risk for breast cancer (as in the hereditary syndromes mentioned above) but they may slightly increase the person’s risk to develop this disease. In this case, the genetic alteration initially affects one cell which becomes malignant over time. That cell then multiplies and all of its descendants will also have the genetic alteration. Although 30-40% of breast cancer occurs in women with a family history, the majority of women who get breast cancer do not have any relatives with the disease.

How It Grows

With all cancers, normal cells become abnormal and reproduce additional abnormal cells which no longer function as they should. The growing abnormal cells eventually invade the surrounding healthy tissue.

There are different types of breast cancer. Some cancers grow slowly. One cell may divide every 100 days, potentially taking up to 8 years for cells to reproduce enough to form a mass that can be felt or seen on a mammogram.

Other breast cancers are very aggressive. They grow faster and become evident earlier. Aggressive breast cancers are more difficult to treat.

Origins of Breast Cancer

There are two origins for cancer within the breast:

Ductal carcinoma – Begins in the milk ducts
Lobular carcinoma – Begins in the milk lobules where milk is produced.

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Advancement of Breast Cancer

Breast cancer may spread from its site of origin. Following are the terms used to indicate if the cancer has spread or not:

In Situ

This is early stage cancer that is confined to it site of origin. The cancer is in the milk ducts or lobules, but has not invaded the fatty tissue of the breast. It can involve a small or large area of the breast.

Infiltrating

This is more advanced cancer that has spread from its site of origin into the fatty tissue of the breast. From here, the cancer can spread to other areas of the body.

Types of Breast Cancer

There are many different types of breast cancer; however two types account for the majority of cases.

All breast cancers need adequate treatment in order to have a good outcome. The earlier breast cancer is detected, the more likely it is that treatment will be successful. The treatment of cancer involves getting rid of the abnormal or diseased tissue (local control) and protecting the rest of the body (systemic control).

DCIS - Ductal Carcinoma In Situ

DCIS is an early, noninvasive breast cancer that is still contained in the milk duct system.

Surgical removal is necessary, either with a lumpectomy or mastectomy depending upon the extent. Being a very treatable entity, DCIS generally requires a lumpectomy rather than a mastectomy. Lymph nodes may not need to be surgically removed, but radiation may be recommended. Chemotherapy is not usually necessary.

A mammogram is the best way to find DCIS early. A breast MRI may be done to determine the extent of the disease as it is very important to remove all DCIS.

IDC - Infiltrating Ductal Carcinoma

This is the most common breast cancer, accounting for 80% of all diagnosed breast cancers. It may be felt or may only show on a mammogram or ultrasound.

This cancer begins in the milk ducts and breaks through the duct wall and invades the fatty tissue of the breast. From there it can spread to other parts of the body.

When found early and treated adequately, the outcome is usually very good.

ILC - Infiltrating Lobular Carcinoma

This type occurs in about 10-15% of all breast cancers. It starts in the milk lobules instead of the ducts.

With ILC, the cancer cells filter into the surrounding tissue without creating a wall, as seen in Infiltrating Duct Cancer. Consequently, you may feel more of a thickening in an area of your breast, rather than a distinguishable lump. This type of cancer is also harder to detect with a mammogram.

Other Infiltrating Breast Carcinomas

There are other types of breast cancers that account for a small minority of cases:

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Types of Premalignant Abnormalities

A mammogram may also identify pre-malignant abnormalities in the breasts. These are not cancer, but indicate that you have a higher likelihood of developing breast cancer. There are two common types of pre-malignant abnormalities:

ADH - Atypical Duct Hyperplasia

ADH is regarded as a pre-cancer because normal cells have abnormal changes.

Women with ADH have a significantly greater likelihood of developing breast cancer. Consequently, surgical removal (through an excisional biopsy) is recommended if significant amounts of atypical cells are found.

LCIS/ALH - Lobular Carcinoma In Situ or Atypical Lobular Hyperplasia

LCIS and ALH are not considered cancers by many experts. However, they are markers that indicate a higher risk of developing breast cancer. They may be indicative of cancer somewhere in either breast - now or at a later time.

A breast MRI may be helpful in determining the presence of more cancer. Surgery may be recommended based upon the MRI findings.

Symptoms of Breast Cancer

The most common sign of breast cancer in both men and women is a lump or thickening in the breast. Other signs of breast cancer include:

Know Your Risk for Breast Cancer

Sally Jobe Breast Centres use the Gail Risk Assessment Tool as an initial screen to assess breast cancer risk in our patients. However, in certain circumstances, the Gail model may under- or overestimate risk. For example, the Gail model may underestimate risk for patients who have a family history of ovarian cancer or for those who have a family history of breast cancer in second-degree relatives (i.e. aunts, grandmother) . Additional models are available in these situations and patients can request a more detailed breast cancer risk assessment through the Risk Assessment and Prevention Program at Invision Sally Jobe. Understanding a patient’s risk for breast cancer is important because national guidelines recommend additional screening and medical management options based on risk. These options may include earlier mammograms, annual breast MRI screening, and/or chemoprevention (using medications to reduce the risk of breast cancer).

Hereditary Breast Cancer

Breast cancer can be caused by a specific hereditary cancer syndrome. The most common of these is called hereditary breast and ovarian cancer syndrome and is caused by mutations in the BRCA1 and BRCA2 genes. Genetic counseling/testing is available through the Risk Assessment and Prevention Program at Invision Sally Jobe. Risk factors for hereditary breast and ovarian cancer include any of the following in a patient or their family: