What Is Breast Cancer?
Breast cancer starts when cells in the breast begin to grow out of control. These cells usually form a tumor that can often be seen on an x-ray or felt as a lump. The tumor is determined to be malignant (cancerous) if the cells can grow into (invade) surrounding tissues or spread (metastasize) to distant areas of the body. Breast cancer occurs almost entirely in women, but men can get breast cancer, too.
Where breast cancer starts
Breast cancers can start from different parts of the breast. Most breast cancers begin in the ducts that carry milk to the nipple (ductal cancers). Some start in the glands that make breast milk (lobular cancers). There are also other types of breast cancer that are less common.
Although many types of breast cancer can cause a lump in the breast, not all do. Many breast cancers are found on screening mammograms which can detect cancers at an earlier stage, often before they can be felt, and before symptoms develop. There are other symptoms of breast cancer you should watch for and report to a health care provider.
It’s also important to understand that most breast lumps are benign and not cancer (malignant). Non-cancerous breast tumors are abnormal growths, but they do not spread outside of the breast and they are not life threatening. But some benign breast lumps can increase a woman’s risk of getting breast cancer. Any breast lump or change needs to be checked by a health care professional to determine if it is benign or malignant (cancer) and if it might affect your future cancer risk.
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- Lymph nodes inside the chest near the breast bone (internal mammary lymph nodes)
If cancer cells have spread to your lymph nodes, there is a higher chance that the cells could have traveled through the lymph system and spread (metastasized) to other parts of your body. The more lymph nodes with breast cancer cells, the more likely it is that the cancer may be found in other organs. Because of this, finding cancer in one or more lymph nodes often affects your treatment plan. Usually, you will need surgery to remove one or more lymph nodes to know whether the cancer has spread.
Still, not all women with cancer cells in their lymph nodes develop metastases, and some women with no cancer cells in their lymph nodes develop metastases later.
How Common Is Breast Cancer?
Breast cancer is the most common cancer in American women, except for skin cancers. Currently, the average risk of a woman in the United States developing breast cancer sometime in her life is about 12%. This means there is a 1 in 8 chance she will develop breast cancer. This also means there is a 7 in 8 chance she will never have the disease.
Current year estimates for breast cancer
The American Cancer Society’s estimates for breast cancer in the United States for 2018 are:
- About 266,120 new cases of invasive breast cancer will be diagnosed in women.
- About 63,960 new cases of carcinoma in situ (CIS) will be diagnosed (CIS is non-invasive and is the earliest form of breast cancer).
- About 40,920 women will die from breast cancer.
Trends in breast cancer incidence
In recent years, incidence rates of breast cancer have been stable in white women and increasing slightly (by 0.3% per year) in African American women. Breast cancer is more common in these women, compared to women of other races/ethnicities.
Trends in breast cancer deaths
Breast cancer is the second leading cause of cancer death in women (only lung cancer kills more women each year). The chance that a woman will die from breast cancer is about 1 in 38 (about 2.6%).
Death rates from female breast cancer dropped 39% from 1989 to 2015. Since 2007, breast cancer death rates have been steady in women younger than 50, but have continued to decrease in older women.
These decreases are believed to be the result of finding breast cancer earlier through screening and increased awareness, as well as better treatments.
Breast cancer survivors
Currently, there are over 3.1 million breast cancer survivors in the United States. This includes women still being treated and those who have completed treatment.
Breast Cancer Signs and Symptoms
It’s important to women breast health that they know how their breasts normally look and feel. Finding breast cancer as early as possible gives women a better chance of successful treatment. But, knowing what to look for does not take the place of having regular mammograms and other screening tests. These tests can help find breast cancer in its early stages, before any symptoms appear.
Lump in the breast
The most common symptom of breast cancer is a new lump or mass. A painless, hard mass that has irregular edges is more likely to be cancer, but breast cancers can be tender, soft, or rounded. They can even be painful. For this reason, it is important to have any new breast mass, lump, or breast change checked by a health care professional experienced in diagnosing breast diseases.
Other possible symptoms of breast cancer include:
- Swelling of all or part of a breast (even if no distinct lump is felt)
- Skin irritation or dimpling (sometimes looking like an orange peel)
- Breast or nipple pain
- Nipple retraction (turning inward)
- Redness, scaliness, or thickening of the nipple or breast skin
- Nipple discharge (other than breast milk)
Sometimes a breast cancer can spread to lymph nodes under the arm or around the collar bone and cause a lump or swelling there, even before the original tumor in the breast is large enough to be felt. Swollen lymph nodes should also be checked by a health care provider.
Although any of these symptoms can be caused by things other than breast cancer, they should be reported to a doctor to determine the cause.
Because mammograms do not find every breast cancer, it is important for women to be aware of changes in their breasts and know the signs and symptoms of breast cancer.
Source: American Cancer Society