What Should I Know About Breast Cancer?

What should I know about breast cancer?

Picture of breast cancer
Picture of breast cancer

How common is breast cancer?

Breast cancer is the most common non-skin cancer of American women, but it can also occur in men. Every year in the US, there are over 266,000 new diagnoses of breast cancer. A woman has a risk of 1 in 8 for developing breast cancer at some point during her lifetime.

Are there early signs of breast cancer? How do I know if I have breast cancer?

There usually are no symptoms or signs of early breast cancer, but sometimes a mass or lump in the breast will be present. Many early breast cancers are first identified by screening mammography. Breast cancer screening is important because the cancers can usually be identified at an early stage, when treatments are likely to be effective and outcomes are better.

What causes breast cancer?

The exact cause of breast cancer is not fully understood, but we know that the risk of breast cancer increases as we age. Other risk factors for breast cancer include a personal or family history of breast cancer and the presence of certain benign conditions in the breast. People who have inherited certain genetic mutations (BRCA1, BRCA2) are also at increased risk of getting breast cancer and other cancers.

Breast cancer facts

  • Breast cancer is the most common cancer among American women.
  • One in every eight women in the United States develops breast cancer.
  • There are many types of breast cancer that differ in their capability of spreading (metastasize) to other body tissues.
  • The causes of breast cancer are not yet fully known, although a number of risk factors have been identified.
  • There are many different types of breast cancer.
  • Breast cancer symptoms and signs include
    • a lump in the breast or armpit,
    • bloody nipple discharge,
    • inverted nipple,
    • orange-peel texture or dimpling of the breast's skin,
    • breast pain or sore nipple,
    • swollen lymph nodes in the neck or armpit, and
    • a change in the size or shape of the breast or nipple.
    • Breast cancer can also be symptom-free, which makes following national screening recommendations an important practice.
  • Medical professionals diagnose breast cancer during a physical exam, by a self-exam of the breasts, mammography, ultrasound testing, and biopsy.
  • Treatment of breast cancer depends on the type of cancer and its stage (0-IV) and may involve surgery, radiation, or chemotherapy.

According to the American Cancer Society and the National Cancer Institute in 2018...

  • over 265,000 new cases of invasive breast cancer will be diagnosed each year in women and over 2,200 in men;
  • approximately 40,000 women and 480 men will die;
  • there are over 3.1 million breast cancer survivors in the United States;
  • the five-year survival for all breast cancer patients is nearly 90%;
  • although breast cancer awareness and survival have increased significantly in the United States for all races, several studies have cited a significantly worse survival rate for African-American women compared to white women;
  • breast cancer is the most common cause of death in Hispanic women; and
  • guidelines for mammography differ depending on the organization making recommendations. Currently, the American Cancer Society recommends yearly mammograms for women aged 45-54 for women at average risk for breast cancer and mammograms every two years for women aged 55 and older, who should also have the option to continue yearly screening.

QUESTION

A lump in the breast is almost always cancer. See Answer

What is breast cancer?

Breast cancer definition

Breast cancer is a malignant tumor (a collection of cancer cells) arising from the cells of the breast. Although breast cancer predominantly occurs in women, it can also affect men. This article deals with breast cancer in women. Breast cancer and its complications can affect nearly every part of the body.

What are the statistics on male breast cancer?

Breast cancer is rare in men (approximately 2,400 new cases diagnosed per year in the U.S.) but typically has a significantly worse outcome. This is partially related to the often late diagnosis of male breast cancer, when the cancer has already spread.

Symptoms and signs of breast cancer in men are similar to the signs and symptoms in women, with the most common symptom being

Although it can occur at any age, male breast cancer usually occurs in men over 60 years of age.

What are the different types of breast cancer?

There are many types of breast cancer. Some are more common than others, and there are also combinations of cancers. Some of the most common types of cancer are as follows:

  • Ductal carcinoma in situ: The most common type of noninvasive breast cancer is ductal carcinoma in situ (DCIS). This early stage breast cancer has not spread and therefore usually has a very high cure rate.
  • Invasive ductal carcinoma: This cancer starts in the milk ducts of the breast and grows into other parts of the surrounding tissue. It is the most common form of breast cancer. About 80% of invasive breast cancers are invasive ductal carcinoma.
  • Invasive lobular carcinoma: This breast cancer starts in the milk-producing glands of the breast. Approximately 10% of invasive breast cancers are invasive lobular carcinoma.

The remainder of breast cancers are much less common and include the following:

  • Mucinous carcinoma are formed from mucus-producing cancer cells. Mixed tumors contain a variety of cell types.
  • Medullary carcinoma is an infiltrating breast cancer that presents with well-defined boundaries between the cancerous and noncancerous tissue.
  • Inflammatory breast cancer: This cancer makes the skin of the breast appear red and feel warm (giving it the appearance of an infection). These changes are due to the blockage of lymph vessels by cancer cells.
  • Paget's disease of the nipple: This cancer starts in the ducts of the breast and spreads to the nipple and the area surrounding the nipple. It usually appears with crusting and redness around the nipple.
  • Adenoid cystic carcinoma: These cancers have both glandular and cystic features. They tend not to spread aggressively and have a good prognosis.
  • Lobular carcinoma in situ: This is not a cancer but an area of abnormal cell growth. This precancer can increase the risk of invasive breast cancer later in life.
  • Adenoid cystic carcinoma: These cancers have both glandular and cystic features. They tend not to spread aggressively and have a good prognosis.
  • Lobular carcinoma in situ: This is not a cancer but an area of abnormal cell growth. This precancer can increase the risk of invasive breast cancer later in life.

The following are other uncommon types of breast cancer:

  • Papillary carcinoma
  • Phyllodes tumor
  • Angiosarcoma
  • Tubular carcinoma

SLIDESHOW

Breast Cancer Diagnosis and Treatment See Slideshow

What causes breast cancer?

There are many risk factors that increase the chance of developing breast cancer. Although we know some of these risk factors, we don't know the cause of breast cancer or how these factors cause the development of a cancer cell.

We know that normal breast cells become cancerous because of mutations in the DNA, and although some of these are inherited, most DNA changes related to breast cells are acquired during one's life.

Proto-oncogenes help cells grow. If these cells mutate, they can increase growth of cells without any control. Such mutations are referred to as oncogenes. Such uncontrolled cell growth can lead to cancer.

What are breast cancer risk factors?

Some of the breast cancer risk factors can be modified (such as alcohol consumption) while others cannot be influenced (such as age). It is important to discuss these risks with a health care provider when starting new therapies (for example, postmenopausal hormone therapy).

Several risk factors are inconclusive (such as deodorants), while in other areas, the risk is being even more clearly defined (such as alcohol use).

The following are risk factors for breast cancer:

  • Age: The chances of breast cancer increase as one gets older.
  • Family history: The risk of breast cancer is higher among women who have relatives with the disease. Having a close relative with the disease (sister, mother, daughter) doubles a woman's risk.
  • Personal history: Having a breast cancer diagnosis in one breast increases the risk of cancer in the other breast or the chance of an additional cancer in the original breast.
  • Women diagnosed with certain benign (non-cancerous) breast conditions have an increased risk of breast cancer. These include atypical hyperplasia, a condition in which there is abnormal proliferation of breast cells but no cancer has developed.
  • Menstruation: Women who started their menstrual cycle at a younger age (before 12) or went through menopause later (after 55) have a slightly increased risk.
  • Breast tissue: Women with dense breast tissue (as documented by mammogram) have a higher risk of breast cancer.
  • Race: White women have a higher risk of developing breast cancer, but African-American women tend to have more tumors that are aggressive when they do develop breast cancer.
  • Exposure to previous chest radiation or use of diethylstilbestrol increases the risk of breast cancer.
  • Having no children or the first child after age 30 increases the risk of breast cancer.
  • Breastfeeding for one and a half to two years might slightly lower the risk of breast cancer.
  • Being overweight or obese increases the risk of breast cancer both in pre- and postmenopausal women but at different rates.
  • Use of oral contraceptives in the last 10 years increases the risk of breast cancer slightly.
  • Using combined hormone therapy after menopause increases the risk of breast cancer.
  • Alcohol consumption increases the risk of breast cancer, and this seems to be proportional to the amount of alcohol used. A recent meta-analysis reviewing the research on alcohol use and breast cancer concluded that all levels of alcohol use are associated with an increased risk for breast cancer. This includes even light drinking.
  • Exercise seems to lower the risk of breast cancer.
  • Genetic risk factors: The most common causes are mutations in the BRCA1 and BRCA2 genes (breast cancer and ovarian cancer genes). Inheriting a mutated gene from a parent means that one has a significantly higher risk of developing breast cancer.

Do antiperspirants or deodorants cause breast cancer?

Research has shown that parabens (a preservative used in deodorants) can build up in breast tissues. However, this study did not show that parabens cause breast cancer or find a link between parabens (which many other products contain) and deodorant use.

A 2002 study did not show any increased risk for breast cancer in women using an underarm deodorant or antiperspirant. A 2003 study showed an earlier age for breast cancer diagnosis in women who shaved their underarms more frequently and used underarm deodorants.

We need more research to give us the answer about a relationship between breast cancer and underarm deodorants and blade shaving.

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Medically Reviewed on 1/6/2020
References
Kroener, L., D. Dumesic, and Z. Al-Safi. "Use of fertility medications and cancer risk: a review and update." Curr Opin Obstet Gynecol May 22, 2017.

Salerno, K.E. "NCCN Guidelines Update: Evolving Radiation Therapy Recommendations for Breast Cancer." J Natl Compr Canc Netw 15(5S) May 2017: 682-684.

Shield, Kevin D., et al. "Alcohol Use and Breast Cancer: A Critical Review." Alcoholism: Clinical and Experimental Research Apr. 30, 2016.
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