What is breast cancer?

Breast cancer is a disease in which malignant (cancer) cells form in the tissues of the breast. The damaged cells can invade surrounding tissue, but with early detection and treatment, most people continue a normal life.

Facts about Breast Cancer in the United States

• One in eight women will be diagnosed with breast cancer in their lifetime.
• Breast cancer is the most commonly diagnosed cancer in women.
• Breast cancer is the second leading cause of death among women.
• Each year it is estimated that over 220,000 women in the United States will be diagnosed with breast cancer and more than 40,000 will die.
• Although breast cancer in men is rare, an estimated 2,150 men will be diagnosed with breast cancer and approximately 410 will die each year.

A Global Burden

According to the World Health Organization, breast cancer is the most common cancer among women worldwide, claiming the lives of hundreds of thousands of women each year and affecting countries at all levels of modernization.

Causes of Breast Cancer: How did this happen?

When you’re told that you have breast cancer, it’s natural to wonder what may have caused the disease. But no one knows the exact causes of breast cancer. Doctors seldom know why one woman develops breast cancer and another doesn’t, and most women who have breast cancer will never be able to pinpoint an exact cause. What we do know is that breast cancer is always caused by damage to a cell’s DNA.

Known Risk Factors

Women with certain risk factors are more likely than others to develop breast cancer. A risk factor is something that may increase the chance of getting a disease. Some risk factors (such as drinking alcohol) can be avoided. But most risk factors (such as having a family history of breast cancer) can’t be avoided. Having a risk factor does not mean that a woman will get breast cancer. Many women who have risk factors never develop breast cancer.

What causes breast cancer growth?

There is much that we know and much that we have yet to understand. However, we do know that cancer spreads in three important ways:

Damaged cells replicate, creating more damaged cells and tumor growth.

Healthy cells are the basic building blocks of all tissue and organs in the body. But when cell DNA (the cell’s wiring) is damaged, mutated cells begin to rapidly reproduce without following the pre-wired plan. Aggressive cell growth can form a tumor (or mass of tissue) that does not function as originally intended. These abnormal cells or groups of cells can progress into the disease known as breast cancer and can spread to other parts of the body

Our body’s hormones and chemicals can accelerate the growth of some tumors.

The growth and spread of breast cancer can be difficult to grasp because cancer cell growth is often fueled by normally healthy chemicals of the body, like estrogen, progesterone, and the HER2/neu gene (a growth hormone). Although each of these three bodily chemicals can serve an important healthy function, when a cell becomes cancerous these chemicals can accelerate the growth of breast cancer tumors.

 Lymph and blood vessels can carry the cancer to others areas of the body and lymph node examination can help pinpoint the progression of the disease.

Healthy HER2 receptors are the proteins that help manage how a breast cell grows, divides, and repairs itself. However, in about a quarter of all breast cancer patients, the HER2 gene isn’t functioning properly. It makes an excess number of copies of itself in a process known as “HER2 gene amplification.” Then these extra genes instruct the cells to make too many HER2 receptors, which is called “HER2 protein overexpression.” The ultimate result is that breast cells grow and divide in an uncontrolled fashion.

What Do Scientists Actually Know about the Cause of Breast Cancer?

Cancer grows when a cell’s DNA is damaged, but why or how that DNA becomes damaged is still unknown. It could be genetic or environmental, or in most cases, a combination of the two. But most patients will never know exactly what caused their cancer. However, there are certain established risk factors that are associated with breast cancer.

Genetic Factors

• Gender:  Breast cancer occurs nearly 100 times more often in women than in men.
• Age:  Two out of three women with invasive cancer are diagnosed after age 55.
• Race:  Breast cancer is diagnosed more often in Caucasian women than women of other races.
• Family History and Genetic Factors:  If your mother, sister, father or child has been diagnosed with breast or ovarian cancer, you have a higher risk of being diagnosed with breast cancer in the future. Your risk increases if your relative was diagnosed before the age of 50.
• Personal Health History:  If you have been diagnosed with breast cancer in one breast, you have an increased risk of being diagnosed with breast cancer in the other breast in the future. Also, your risk increases if abnormal breast cells have been detected before (such as atypical hyperplasia, lobular carcinoma in situ (LCIS) or ductal carcinoma in situ (DCIS)).
• Menstrual and Reproductive History:  Early menstruation (before age 12), late menopause (after 55), having your first child at an older age, or never having given birth can also increase your risk for breast cancer.
• Certain Genome Changes:  Mutations in certain genes, such as BRCA1 and BRCA2, can increase your risk for breast cancer. This is determined through a genetic test, which you may consider taking if you have a family history of breast cancer. Individuals with these gene mutations can pass the gene mutation onto their children.
• Dense Breast Tissue:  Having dense breast tissue can increase your risk for breast cancer and make lumps harder to detect.

What Are The Stats?

60-70% of people with breast cancer have no connection to these risk factors at all, and other people with risk factors will never develop cancer.

These do not cause breast cancer

Breast cancer is not contagious; you can’t contract cancer from a person who has the disease.

Breast cancer is not caused by wearing underwire bras, implants, deodorants, antiperspirants, mammograms, caffeine, plastic food serving items, microwaves, or cell phones, as myths often suggest.

Good News About Breast Cancer Trends

In recent years, perhaps coinciding with the decline in prescriptive hormone replacement therapy after menopause, we have seen a gradual reduction in female breast cancer incidence rates among women aged 50 and older. Death rates from breast cancer have been declining since about 1990, in part to better due to screening and early detection, increased awareness, and continually improving treatment options.