Breast cancer is an invasive cancer. The main cause of breast cancer is genetic mutation or damage to a person’s DNA.
A note about sex and gender
Sex and gender exist on spectrums. This article will use the terms “male,” “female,” or both to refer to sex assigned at birth. Click here to learn more.
A 2019 study showed, however, that the rate in the United States may no longer be declining in women aged 20–39 years.
The American Cancer Society (ACS) reports that:
- There are more than
3.8 million breastcancer survivors in the U.S.
- The chance of dying from breast cancer is around 1 in 38 (2.6%).
- About 281,550 new cases of invasive breast cancer will be diagnosed by the end of 2021
- About 43,600 deaths from breast cancer are likely to occur by the end of 2021
Awareness of the symptoms and the need for screening is key in reducing the risk of mortality.
In rare instances, breast cancer can also affect males. This article will focus on breast cancer in females.
Learn about breast cancer in males here.
The first symptom of breast cancer is usually an area of thickened tissue in the breast or a lump in the breast or an armpit.
- armpit or breast pain does not change with the monthly cycle
- pitting, like the surface of an orange, or color changes such as redness in the skin of the breast
- a rash around or on one nipple
- discharge from a nipple, which may contain blood
- a sunken or inverted nipple
- a change in the size or shape of the breast
- peeling, flaking, or scaling of the skin of the breast or nipple
Most breast lumps are not cancerous. However, anyone who notices a breast lump should have it checked by a healthcare professional.
A lump or a mass in the breast is
Pain caused by breast cancer is typically gradual. Anyone who experiences breast pain, especially if it is severe or persistent, should consult a healthcare professional.
After puberty, a female’s breasts are made up of fat, connective tissue, and thousands of lobules. These are tiny glands that can produce milk. Tiny tubes, or ducts, carry the milk toward the nipple.
Breast cancer develops as a result of genetic mutations or damage to DNA. These can be
When a person is healthy, their immune system attacks any abnormal DNA or growths. When a person has cancer, this does not happen.
As a result, cells within breast tissue begin to multiply uncontrollably, and they do not die as usual. This excessive cell growth forms a tumor that deprives surrounding cells of nutrients and energy.
Breast cancer usually starts in the inner lining of the milk ducts or the lobules that supply them with milk. From there, it can spread to other parts of the body.
A doctor determines the stage of cancer according to the size of the tumor and whether it has spread to lymph nodes or other parts of the body.
- Stage 0: This is also called ductal carcinoma in situ. The cancerous cells are only within the ducts and have not spread to surrounding tissues.
- Stage 1: At this stage, the tumor measures up to 2 centimeters (cm) across. It has not affected any lymph nodes, or there are small groups of cancer cells in lymph nodes.
- Stage 2: The tumor is 2 cm across and has started to spread to nearby nodes, or it is 2–5 cm across and has not spread to the lymph nodes.
- Stage 3: The tumor is up to 5 cm across and has spread to several lymph nodes, or the tumor is larger than 5 cm and has spread to a few lymph nodes.
- Stage 4: The cancer has spread to distant organs, most often the bones, liver, brain, or lungs.
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The following factors make developing breast cancer more likely, and some may be preventable.
The risk of breast cancer increases with age. At 20 years old, the chance of developing breast cancer in the next decade is 0.06%. By the age of 70, this figure goes up to 3.84%.
Mutations in the TP53 gene also have links to increased breast cancer risk.
If a close relative has or has had breast cancer, a person’s chance of developing breast cancer increases.
People should also receive this testing, the guidelines state, if there is a history of breast cancer related to BRCA1 or BRCA2 gene mutations in their ancestry. This applies to people, for example, with Ashkenazi Jewish ancestry.
History of breast cancer or breast lumps
A person who has had breast cancer is
Having some types of noncancerous breast lumps increases the risk of developing the cancer later on. Examples include atypical ductal hyperplasia or lobular carcinoma in situ.
People with a history of breast, ovarian, fallopian tube, or peritoneal cancer should ask their doctors about genetic testing.
Dense breast tissue
Dense breast tissue is more likely to be associated with a diagnosis of breast cancer.
Estrogen exposure and breastfeeding
Extended exposure to estrogen appears to increase the risk of breast cancer.
This exposure could involve starting periods at an early age or entering menopause late. Between these times, estrogen levels in the body are higher.
Breastfeeding, especially for over 1 year, appears to reduce the risk of developing breast cancer. This may be due to the drop in estrogen exposure that follows pregnancy and breastfeeding.
Regularly drinking high amounts of alcohol appears to play a role in breast cancer development.
According to the
Undergoing radiation treatment for a different cancer may increase the risk of developing breast cancer later in life.
Studies have shown that oral contraceptives may slightly increase the risk of breast cancer, the
As the Centers for Disease Control and Prevention (CDC) report, breast cancer mortality is about
The reasons for this are likely biological and socioeconomic. For example, according to a
Cosmetic implants and breast cancer survival
The general agreement, based on
In 2021, another study found that women with cosmetic implants have significantly lower rates of breast cancer than those who do not have them.
However, this research did not factor in other variables that may influence breast cancer mortality, such as body mass index, age at diagnosis, or cancer stage at diagnosis. And at least one of the studies in the analysis looked at overall mortality, instead of breast cancer-specific mortality, thereby potentially skewing the results. As such, a person should consider the finding with caution.
There are several types of breast cancer. The
“Invasive” breast cancer involves cancerous cells spreading to nearby tissue. It is then more likely that the cancer will spread to other parts of the body.
“Noninvasive” breast cancer remains in its place of origin. These cells may eventually become invasive.
A doctor often diagnoses breast cancer as a result of routine screening or when a person reports symptoms. Below, we describe tests and procedures that can help the doctor make and confirm the diagnosis.
This involves checking the breasts for lumps and other possible indications of cancer.
During the examination, the person may need to sit or stand with their arms in different positions, such as above their head or by their sides.
Several types of scans can help detect breast cancer, including:
Mammogram: This is a type of X-ray that doctors commonly use during initial breast cancer screening. It produces images that can show lumps or abnormalities. If there is any sign of a potential problem, the doctor usually conducts further testing.
Ultrasound: This scan uses sound waves to help a doctor differentiate between a solid mass and a fluid-filled cyst.
MRI: This combines different images of the breast to help a doctor identify cancer or other abnormalities. A doctor may recommend an MRI as a follow-up to a mammogram or ultrasound. Doctors may also use MRIs to screen people with a higher risk of breast cancer.
This involves extracting a sample of tissue and sending it to a laboratory for analysis.
The results show whether the cells are cancerous, and if they are, which type of cancer has developed. The results can even show whether the cancer is hormone-sensitive.
The doctor then stages the cancer to establish:
- the size of a tumor
- how far it has spread
- whether it is invasive
This can provide information about the outlook and the best course of treatment.
The most effective approach depends on several factors, including:
- the type and stage of the cancer
- the sensitivity to hormones
- the person’s age, overall health, and preferences
The main treatment options include:
If surgery is necessary, the type depends on the diagnosis and the person’s preferences. Types of surgery include:
Lumpectomy: This involves removing the tumor and a small amount of healthy tissue around it.
A lumpectomy can help prevent the spread of cancer. This may be an option if the tumor is small and easy to separate from surrounding tissue.
Mastectomy: A simple mastectomy involves removing the breast’s lobules, ducts, fatty tissue, nipple, areola, and some skin. In some types, a surgeon also removes the lymph nodes and muscle in the chest wall.
Sentinel node biopsy: If breast cancer reaches the sentinel lymph nodes, the first nodes to which it can spread, it can travel to other parts of the body through the lymphatic system. If the doctor does not find cancer in the sentinel nodes, it is usually not necessary to remove other nodes.
Axillary lymph node dissection: If a doctor finds cancer cells in the sentinel nodes, they may recommend removing several lymph nodes in the armpit. This can prevent cancer from spreading.
Reconstruction: Following a mastectomy, a surgeon can reconstruct the breast so that it looks more natural. This can help a person cope with the psychological effects of breast removal.
The surgeon can reconstruct the breast during the mastectomy or at a later date. They may use a breast implant or tissue from another part of the body.
A person may undergo radiation therapy around 1 month after surgery. It involves targeting the tumor with controlled doses of radiation that kill any remaining cancer cells.
A doctor may prescribe cytotoxic chemotherapy drugs to kill cancer cells if there is a high risk of recurrence or spread. When a person has chemotherapy after surgery, doctors call it adjuvant chemotherapy.
Sometimes, a doctor may recommend chemotherapy before surgery to shrink the tumor and make it easier to remove. This is called neoadjuvant chemotherapy.
Doctors use hormone-blocking therapy to prevent hormone-sensitive breast cancers from returning after treatment. The therapy may help treat estrogen receptor-positive and progesterone receptor-positive cancers.
Hormone-blocking therapy may be the only option for people who are not suitable candidates for surgery, chemotherapy, or radiotherapy.
Examples of hormone-blocking medications may include:
- tamoxifen (Nolvadex)
- aromatase inhibitors
- ovarian ablation or suppression
- goserelin (Zoladex)
This type of treatment may affect fertility.
Targeted drugs can destroy specific types of breast cancer. Examples include:
- trastuzumab (Herceptin)
- lapatinib (Tykerb)
- bevacizumab (Avastin)
Treatments for breast cancer and other cancers can have severe adverse effects. When deciding on a treatment, discuss the potential risks with a doctor and look for ways to minimize the side effects.
There is no way to prevent breast cancer. However, a person can take steps to significantly reduce their risk.
- limiting alcohol consumption, for people who drink
- having a healthy diet with plenty of fresh fruit and vegetables
- getting enough exercise
- maintaining a moderate body mass index
A person who is considering using hormone replacement therapy after menopause may wish to discuss this with a healthcare professional.
For people with a high risk of breast cancer, preventive surgery is also an option.
The Breast Cancer Healthline app provides access to an online breast cancer community, where users can connect with others and gain advice and support through group discussions. It also classifies survival rates based on how far cancer has spread beyond the breast tissue.
Breast cancer screening
Expert guidelines about how often to have breast cancer screenings differ.
The American College of Physicians recommends that women aged 40–49 years with an average risk of breast cancer discuss the benefits and risks of regular screenings with a doctor.
Women aged 50–74 who have an average risk, the guidelines say, should have screenings every 2 years. Women aged 75 or older should continue with screenings if their life expectancy is 10 or more years.
The ACS suggests that women with an average risk should be able to choose whether to have yearly scans from
The American College of Radiologists recommend screenings every year, starting from 40 years of age.
Despite the variations, most experts recommend at least speaking with a doctor about breast cancer screening from the age of 40 onward.
A survival rate describes how long a person with breast cancer is likely to live after the diagnosis, in comparison with someone who does not have the diagnosis.
The NCI currently estimates that about
It is important to keep in mind that researchers use survival rates to assess large populations. And in calculating this rate, they exclude the risk of dying from other causes.
A survival rate cannot predict an individual’s outlook. No two people necessarily respond to treatment in the same way.
Which other cancers are common in women?
Other than skin cancer, the cancers that most often affect women
- breast cancer
- lung cancer
- colorectal cancer
- uterine cancer
- non-Hodgkin lymphoma
- thyroid cancer
- pancreatic cancer
- kidney cancer
Breast cancer is still a leading cause of cancer death among females. However, the
A person may be able to take steps to prevent breast cancer, such as maintaining a healthy lifestyle and speaking with their doctor about the best pace of screening, beginning at