In the United States, one in 8 women will develop breast cancer sometime in their life.
Dr. Navneet Sharda provides this breast cancer information as an educational source. It is not intended as a substitute for a consultation with a qualified healthcare provider.
Breast cancer is an uncontrolled growth of breast cells. Continued growth of these cells form a tumor that can often be seen on an x-ray or felt as a lump. The tumor is malignant if the cells can grow into surrounding tissues or spread to distant areas of the body.
The breast contains glands called lobules that can produce milk and thin tubes called ducts that carry the milk
from the lobules to the nipple. Breast tissue also contains fat and connective tissue, lymph nodes, and blood vessels. The most common area to become cancerous are the ducts, and the most common type of breast cancer is called invasive ductal carcinoma.
Breast cancer can also begin in the cells of the lobules and in other tissues in the breast. Ductal carcinoma in situ is a condition in which abnormal cells are found in the lining of the ducts but they haven’t spread outside the duct. Breast cancer that has spread from where it began in the ducts or lobules to surrounding tissue is called invasive breast cancer. In inflammatory breast cancer, the breast looks red and swollen and feels warm because the cancer cells block the lymph vessels in the skin. A pathologist looks at the tissue under a microscope and determines whether a tumor removed during a biopsy is ductal or lobular cancer. If he sees tumor within the skin then this is called inflammatory carcinoma. A pathologist is a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease.
To better understand the following breast cancer information, it helps to understand how any cancer can develop.
Cancer occurs as a result of mutations, or abnormal changes, in the genes responsible for regulating the growth of cells and keeping them healthy. The genes are in each cell’s nucleus, which acts as the “control room” of each cell. Normally, the cells in our bodies replace themselves through an orderly process of cell growth: healthy new cells take over as old ones die out. But over time, mutations can “turn on” certain genes and “turn off” others in a cell. That changed cell gains the ability to keep dividing without control or order, producing more cells just like it and forming a tumor.
A tumor can be benign (not dangerous to health) or malignant. Benign tumors are not considered cancerous: their cells are close to normal in appearance, they grow slowly, and they do not invade nearby tissues or spread to other parts of the body. Malignant tumors are cancerous. Left unchecked, malignant cells eventually can spread beyond the original tumor to other parts of the body.
In the US, around 1 in 8 women carry a lifetime risk of invasive breast cancer. In 2011, an estimated 230,480 new cases of invasive breast cancer were expected to be diagnosed in women in the U.S., along with 57,650 new cases of non-invasive (in situ) breast cancer. In addition, around 39,520 women in the U.S. were expected to die in 2011 from breast cancer.
There was a steady decline in breast cancer incidence from 1999 to 2005. The decrease was seen only in women aged 50 and older. This could be due to reduced use of hormone replacement therapy (HRT) by women.
Those with a family history of breast cancer are at double the risk of developing the cancer. About 15% of women who get breast cancer have a family member diagnosed with it. About 5-10% of breast cancers can be linked to gene mutations (abnormal changes) inherited from one’s mother or father. The most common mutations are those of BRCA 1 and BRCA 2. Women with these mutations have up to an 80% risk of developing breast cancer during their lifetime.
For women in the U.S., breast cancer death rates are higher than those for any other cancer, besides lung cancer. However, death rates are on the decline due to advances in therapeutics against breast cancer.
Breast cancer may not cause any signs or symptoms in its early stages. Signs and symptoms often appear when the tumor grows large enough to be felt as a lump in the breast or when the cancer spreads to surrounding tissues and organs. Other health conditions can cause the same symptoms as breast cancer.
The most common symptom of ductal carcinoma is a firm or hard lump that feels very different from the rest of the breast. It may feel like it is attached to the skin or the surrounding breast tissue. The lump doesn’t get smaller or come and go with your period. It may be tender, but it’s usually not painful. (Pain is more often a symptom of a non-cancerous condition).
Lobular carcinoma often does not form a lump. It feels more like the tissue in the breast is getting thicker or harder.
Other symptoms of ductal and lobular breast cancer include: a lump in the armpit (called the axilla); changes in the shape or size of the breast; changes to the nipple, such as a nipple that suddenly starts to point inward (called an inverted nipple); discharge that comes out of the nipple without squeezing it or that has blood in it.
Late signs and symptoms occur as the cancer grows larger or spreads to other parts of the body, including other organs.
Late symptoms of breast cancer include: bone pain, weight loss, nausea, headache, double vision, loss of appetite, jaundice, shortness of breath, cough or muscle weakness.
The things that increase the risk of breast cancer are fairly well understood. The older you are the more likely to develop breast cancer. If you have close family members diagnosed with breast cancer, this also raises your risk. Not having children or delaying your first child until after the age of 30 will also increases the risk. Alcohol intake greater than one drink a day (2 oz alcohol) on a daily basis will increase the chance of breast cancer, and the heavier the drinking the more the risk. Girls who begin menstrual periods early and women who have delayed menopause are at higher risk because the duration of exposure to high levels of estrogen is directly linked to higher risk of breast cancer. Body fat increases estrogen in the body; obesity as well as Diabetes have both been shown to elevate breast cancer risk.
Breast feeding has a significant protective effect against developing breast cancer.