Breast cancer is an uncontrolled growth of breast cells. To better understand breast cancer, 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 (has the potential to be dangerous). 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. The term “breast cancer” refers to a malignant tumor that has developed from cells in the breast. Usually breast cancer either begins in the cells of the lobules, which are the milk-producing glands, or the ducts, the passages that drain milk from the lobules to the nipple. Less commonly, breast cancer can begin in the stromal tissues, which include the fatty and fibrous connective tissues of the breast.
Over time, cancer cells can invade nearby healthy breast tissue and make their way into the underarm lymph nodes, small organs that filter out foreign substances in the body. If cancer cells get into the lymph nodes, they then have a pathway into other parts of the body. The breast cancer’s stage refers to how far the cancer cells have spread beyond the original tumor. Breast cancer is always caused by a genetic abnormality (a “mistake” in the genetic material). However, only 5-10% of cancers are due to an abnormality inherited from your mother or father. Instead, 85-90% of breast cancers are due to genetic abnormalities that happen as a result of the aging process and the “wear and tear” of life in general.
There are steps every person can take to help the body stay as healthy as possible, such as eating a balanced diet, maintaining a healthy weight, not smoking, limiting alcohol, and exercising regularly. While these may have some impact on your risk of getting breast cancer, they cannot eliminate the risk. Developing breast cancer is not your or anyone’s fault. Feeling guilty, or telling yourself that breast cancer happened because of something you or anyone else did, is not productive.
Breast Cancer Risk
You may be familiar with the statistic that says 1 in 8 women will develop invasive breast cancer. Many people misinterpret this to mean that, on any given day, they and the women they know have a 1-in-8 risk of developing the disease. That’s simply not true. In reality, about 1 in 8 women— 12%, or about 12 out of every 100 — can expect to develop breast cancer over the course of an entire lifetime. In the U.S, an average lifetime is about 80 years. So, it’s more accurate to say that 1 in 8 women who reach the age of 80 can expect to develop breast cancer. In each decade of life, the risk of getting breast cancer is actually lower than 12% for most women.
Even though studies have found that women have a 12% lifetime risk of developing breast cancer, your individual risk may be higher or lower than that. Individual risk is affected by many different factors, such as family history, reproductive history, lifestyle, environment, and others.
Breast Cancer Risk Factors
A “risk factor” is anything that increases your risk of developing breast cancer. Many of the most important risk factors for breast cancer are beyond your control, such as age, family history, and medical history. However, there are some risk factors you can control, such as weight, physical activity, and alcohol consumption.
Risk factors you can control
Weight. Being overweight is associated with increased risk of breast cancer, especially for women after menopause. Fat tissue is the body’s main source of estrogen after menopause, when the ovaries stop producing the hormone. Having more fat tissue means having higher estrogen levels, which can increase breast cancer risk.
Diet. Diet is a suspected risk factor for many types of cancer, including breast cancer, but studies have yet to show for sure which types of foods increase risk. It’s a good idea to restrict sources of red meat and other animal fats (including dairy fat in cheese, milk, and ice cream), because they may contain hormones, other growth factors, antibiotics, and pesticides. Some researchers believe that eating too much cholesterol and other fats are risk factors for cancer, and studies show that eating a lot of red and/or processed meats is associated with a higher risk of breast cancer. A low-fat diet rich in fruits and vegetables is generally recommended.
Exercise. Evidence is growing that exercise can reduce breast cancer risk. The American Cancer Society recommends engaging in 45-60 minutes of physical exercise 5 or more days a week.
Alcohol consumption. Studies have shown that breast cancer risk increases with the amount of alcohol a woman drinks. Alcohol can limit your liver’s ability to control blood levels of the hormone estrogen, which in turn can increase risk.
Smoking. Smoking is associated with a small increase in breast cancer risk. Exposure to estrogen. Because the female hormone estrogen stimulates breast cell growth, exposure to estrogen over long periods of time, without any breaks, can increase the risk of breast cancer. Some of these risk factors are under your control, such as:
- Taking combined hormone replacement therapy (estrogen and progesterone; HRT) for several years or more, or taking estrogen alone for more than 10 years
- Being overweight
- Regularly drinking alcohol
Recent oral contraceptive use. Using oral contraceptives (birth control pills) appears to slightly increase a woman’s risk for breast cancer, but only for a limited period of time. Women who stopped using oral contraceptives more than 10 years ago do not appear to have any increased breast cancer risk.
Stress and anxiety. There is no clear proof that stress and anxiety can increase breast cancer risk. However, anything you can do to reduce your stress and to enhance your comfort, joy, and satisfaction can have a major effect on your quality of life. So-called “mindful measures” (such as meditation, yoga, visualization exercises, and prayer) may be valuable additions to your daily or weekly routine. Some research suggests that these practices can strengthen the immune system.
Risk factors you can’t control
Gender. Being a woman is the most significant risk factor for developing breast cancer. Although men can get breast cancer, too, women’s breast cells are constantly changing and growing, mainly due to the activity of the female hormones estrogen and progesterone. This activity puts them at much greater risk for breast cancer.
Age. Simply growing older is the second biggest risk factor for breast cancer. From age 30 to 39, the risk is 1 in 228, or .44%. That jumps to 1 in 29, or just under 43.5%, by the time you are in your 60s.
Family history of breast cancer. If you have a first-degree relative (mother, daughter, sister) who has had breast cancer, or you have multiple relatives affected by breast or ovarian cancer (especially before they turned age 50), you could be at higher risk of getting breast cancer.
Personal history of breast cancer. If you have already been diagnosed with breast cancer, your risk of developing it again, either in the same breast or the other breast, is higher than if you never had the disease.
Race. White women are slightly more likely to develop breast cancer than are African women. Asian, Hispanic, and Native American women have a lower risk of developing and dying from breast cancer.
Radiation therapy to the chest. Having radiation therapy to the chest area as a child or young adult as treatment for another cancer significantly increases breast cancer risk. The increase in risk seems to be highest if the radiation was given while the breasts were still developing (during the teen years).
Exposure to estrogen. Because the female hormone estrogen stimulates breast cell growth, exposure to estrogen over long periods of time, without any breaks, can increase the risk of breast cancer. Some of these risk factors are not under your control, such as:
- Starting menstruation (monthly periods) at a young age (before age 12)
- Going through menopause (end of monthly cycles) at a late age (after 55)
- Exposure to estrogens in the environment (such as hormones in meat or pesticides such as DDT, which produce estrogen-like substances when broken down by the body)
Pregnancy and breastfeeding. Pregnancy and breastfeeding reduce the overall number of menstrual cycles in a woman’s lifetime, and this appears to reduce future breast cancer risk. Women who have never had a full-term pregnancy, or had their first full-term pregnancy after age 30, have an increased risk of breast cancer. For women who do have children, breastfeeding may slightly lower their breast cancer risk, especially if they continue breastfeeding for 1 1/2 to 2 years. For many women, however, breastfeeding for this long is neither possible nor practical.
Symptoms of Breast Cancer
Initially, breast cancer may not cause any symptoms. A lump may be too small for you to feel or to cause any unusual changes you can notice on your own. Often, an abnormal area turns up on a screening mammogram (X-ray of the breast), which leads to further testing.
In some cases, however, the first sign of breast cancer is a new lump or mass in the breast that you or your doctor can feel. A lump that is painless, hard, and has uneven edges is more likely to be cancer. But sometimes cancers can be tender, soft, and rounded. So it’s important to have anything unusual checked by your doctor.
According to the American Cancer Society, any of the following unusual changes in the breast can be a symptom of breast cancer:
- swelling of all or part of the breast
- skin irritation or dimpling
- breast pain
- nipple pain or the nipple turning inward
- redness, scaliness, or thickening of the nipple or breast skin
- a nipple discharge other than breast milk
- a lump in the underarm area
These changes also can be signs of less serious conditions that are not cancerous, such as an infection or a cyst. It’s important to get any breast changes checked out promptly by a doctor.
Breast self-exam should be part of your monthly health care routine, and you should visit your doctor if you experience breast changes. If you’re over 40 or at a high risk for the disease, you should also have an annual mammogram and physical exam by a doctor. The earlier breast cancer is found and diagnosed, the better your chances of beating it.
The actual process of diagnosis can take weeks and involve many different kinds of tests. Waiting for results can feel like a lifetime. The uncertainty stinks. But once you understand your own unique “big picture,” you can make better decisions. You and your doctors can formulate a treatment plan tailored just for you.
Breast Cancer Tests: Screening, Diagnosis, and Monitoring
Whether you’ve never had breast cancer and want to increase your odds of early detection, you’ve recently been diagnosed, or you are in the midst of treatment and follow-up, you know that breast cancer and medical tests go hand in hand.
Most breast-cancer-related tests fall into one or more of the following categories:
- Screening tests: Screening tests (such as yearly mammograms) are given routinely to people who appear to be healthy and are not suspected of having breast cancer. Their purpose is to find breast cancer early, before any symptoms can develop and the cancer usually is easier to treat.
- Diagnostic tests: Diagnostic tests (such as biopsy) are given to people who are suspected of having breast cancer, either because of symptoms they may be experiencing or a screening test result. These tests are used to determine whether or not breast cancer is present and, if so, whether or not it has traveled outside the breast. Diagnostic tests also are used to gather more information about the cancer to guide decisions about treatment.
- Monitoring tests: Once breast cancer is diagnosed, many tests are used during and after treatment to monitor how well therapies are working. Monitoring tests also may be used to check for any signs of recurrence.
Successfully treating breast cancer means getting rid of the cancer or getting it under control for an extended period of time. But because a breast cancer is made up of many different kinds of cancer cells, getting rid of all those cells can require different types of treatments.
Your treatment plan may include a combination of the following treatments:
- Radiation therapy
- Hormonal Therapy (anti-estrogen therapy)
- Targeted therapy (such as Herceptin, Tykerb, Avastin)
Designing your personal treatment strategy to treat breast cancer requires a lot of careful thought. The ideal treatment plan works against all the things inside the cells that caused the cancer to develop, are making it grow, and may make it spread to other parts of the body.