Breast cancer is the most common invasive cancer in women, and is the second leading cause of death from lung cancer in women.
Advances in breast cancer screening and treatment have dramatically improved overall survival rates since 1989. There are more than 3.1 million breast cancer survivors in the USA, according to the American Cancer Society (ACS). Any woman who suffers from breast cancer has a chance of about 1 in 38 (2.6%).
The ACS predicts that 268,600 women will be diagnosed with invasive breast cancer, and that in 2019, 62,930 people will be diagnosed with non-invasive cancer.
In the same year, the ACS estimates that there will be 41,760 women dying from breast cancer. However, since 1989, death rates from breast cancer have been falling as a result of advances during treatment.
Being aware of the symptoms and the need for screening are important ways to reduce the risk. Breast cancer may also affect men in rare cases but this article will focus on women’s breast cancer.
Typically, the first signs of breast cancer occur as a thickened tissue region in the breast or a lump in the breast or an armpit.
Additional signs include:
- pain in the armpits or breast that does not change with the monthly cycle
- pitting or redness of the skin of the breast, similar to the surface of an orange
- a rash around or on one of the nipples
- discharge from a nipple, possibly containing blood
- a sunken or inverted nipple
- a change in the size or shape of the breast
- peeling, flaking, or scaling of the skin on the breast or nipple
Most breast lumps are not carcinogenic. However, if women notice a lump on the breast they should visit a doctor for an exam.
A doctor will assess cancer by tumor size and whether it has spread to lymph nodes or other parts of the body.
There are various ways to treat breast cancer. One way is from stage 0–4, with categories subdivided at each numerated stage. Descriptions of the four main stages are listed below, although a cancer’s specific substage may also depend on other specific tumor characteristics, such as HER2 receptor status.
- Stage 0: Known as ductal carcinoma in situ (DCIS), the cells are limited to within the ducts and have not invaded 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 the lymph nodes.
- Stage 2: The tumor is 2 cm across, and it has started to spread to nearby nodes, or is 2–5 cm across and has not spread to the lymph nodes.
- Stage 3: The tumor is up to 5 cm across, and it 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.
A woman’s breast after puberty is made of fat, connective tissue and thousands of lobules. These are tiny glands which produce breastfeeding milk. Small tubes, or ducts, hold the milk to the nipple.
Cancer causes uncontrollable proliferation of the cells. They don’t die at their normal lifecycle stage. The rapid growth of cells causes cancer because the tumor requires nutrients and resources, and the cells around it are depleted.
Breast cancer usually begins in the inner lining of milk ducts or in the lobules that provide milk to them. It can spread from there on to other parts of the body.
The exact cause of breast cancer remains unclear but it is made more likely by some risk factors. Many of these risk factors may be avoided.
Through age the risk of breast cancer increases. At 20 years of age, breast cancer is likely to develop 0.06 percent in the next decade. That percentage goes up to 3.84 per cent by the age of 70.
Women who carry certain mutations in the genes BRCA1 and BRCA2 are more likely to develop breast cancer, ovarian cancer or both. Those genes are inherited from their parents.
Mutations in the gene TP53 also have ties to an increased risk of breast cancer.
If a close relative has or has had breast cancer, then the chance for a person to develop breast cancer increases.
Current guidelines recommend looking for genetic testing by people in the following groups:
- those with a family history of breast, ovarian, fallopian tube, or peritoneal cancer
- those in whose ancestry there is a history of breast cancer related to BRCA1 or BRCA2 gene mutations, for example, people with Ashkenazi Jewish ancestry
A history of breast cancer or breast lumps
Women who have had breast cancer before are more likely to have it again than those who do not have the disease history.
Finding these types of noncancerous lump in the breast increases the chance of developing cancer later. Examples include atypical hyperplasia to the duct or in situ lobular carcinoma.
People with a history of breast, ovarian, fallopian tube or peritoneal cancer should inquire for genetic testing from their physicians.
Dense breast tissue
Women with denser breasts are more likely to get the breast cancer diagnosis.
Estrogen exposure and breastfeeding
Extended sensitivity to estrogen appears to make breast cancer more likely.
This could be attributed to a person entering menopause at a later than average age or starting their periods earlier. Between those times the levels of estrogen are higher.
Breastfeeding appears to reduce the chance of developing breast cancer, especially for over 1 year. This may be due to the drop in exposure to estrogen following pregnancy and breastfeeding.
People who become overweight or develop obesity following menopause may also have an increased chance of developing breast cancer, likely due to increased levels of estrogen.
A higher rate of regular alcohol consumption seems to play a part in the development of breast cancer.
Studies have repeatedly found that women who consume alcohol have a higher risk for breast cancer than those who do not, according to the National Cancer Institute (NCI). Those who drink moderate to heavy alcohol levels show a higher risk than light drinkers.
Undergoing treatment with radiation for another cancer can increase the risk of developing breast cancer later in life.
According to the NCI, studies have shown that oral contraceptives may slightly increase the risk of breast cancer
According to the ACS, studies have found that hormone replacement therapy (HRT), specifically estrogen-progesterone therapy (EPT), is related to an increased risk of breast cancer.
Cosmetic implants and breast cancer survival
A 2013 study found that women with silicone breast implants who had the breast cancer diagnosis also had a higher risk of dying from the disease.
This may be due to implants masking cancer during tests or due to changes in breast tissue caused by the implants.
However, a 2015 study published in the Aesthetic Surgery Journal found that the risk of breast cancer was not raised by getting cosmetic breast implant surgery.
Further research is needed by scientists to confirm the connection.
There are several different types of breast cancer, including:
- Ductal carcinoma: This begins in the milk duct and is the most common type.
- Lobular carcinoma: This starts in the lobules.
Invasive breast cancer occurs when the cells in the lobules or ducts break out and invade nearby tissue. That increases the chance of spreading cancer to other parts of the body.
Non-invasive breast cancer develops when the cancer remains and has not yet spread within its place of origin. These cells can sometimes progress toward invasive breast cancer, however.
A doctor frequently suspects breast cancer as a result of routine screening, or as a patient visits her doctor after symptoms have been identified.
Many tests and diagnostic procedures help confirm a diagnosis.
The doctor will screen for lumps and other symptoms in the breasts.
The person may need to sit or stand in different positions with his or her arms during the test, such as above their head or by their sides.
Several tests can help detect breast cancer.
Mammogram: This is a type of X-ray commonly used by doctors during an initial screening for breast cancer. It produces images which can help a doctor detect any abnormalities or lumps.
A doctor will usually take further testing to follow any suspicious results. Mammography, however, sometimes shows a suspicious area, which turns out not to be cancer.
Ultrasound: This scan uses sound waves to help a doctor distinguish between a solid mass and a cyst full of fluid.
MRI: Magnetic Resonance Imaging (MRI) incorporates different breast scans to help a doctor detect cancer or any other abnormality.
As a follow-up to a mammogram or ultrasound a doctor can prescribe an MRI. Doctors also use it as a screening tool for those at greater breast cancer risk.
In a biopsy the doctor extracts a tissue sample and sends it to be analyzed in laboratory.
Which shows whether the cells are cancerous. If they are, a biopsy shows what type of cancer has grown, including whether the cancer is hormone active or not.
Diagnosis also includes cancer stageing to determine:
- the size of a tumor
- how far it has spread
- whether it is invasive or noninvasive
Staging gives an image of a person’s chances of recovery and their ideal treatment course.
Treatment will depend on several factors, including:
- the type and stage of the cancer
- the person’s sensitivity to hormones
- the age, overall health, and preferences of the individual
The main treatment options include:
- biological therapy, or targeted drug therapy
- hormone therapy
Factors affecting a person’s type of treatment will include the cancer level, certain medical conditions and their individual preferences
If surgery is required, the form will depend on the diagnosis as well as the individual preferences. Surgery types include: lumpectomy: this involves the removal of the tumor and a small amount of healthy tissue that is around it.
A lumpectomy may help prevent the cancer from spreading. If the tumor is small and easy to separate from its surrounding tissue, this may be an option.
Mastectomy: A simple mastectomy involves the removal of lobules, ducts, fatty tissue, nipple, isola and some skin. In some types the lymph nodes and muscle in the chest wall will also be removed by a surgeon.
Sentinel node biopsy: If breast cancer reaches the sentinel lymph nodes, which are the first nodes a cancer can spread to, it can spread through the lymphatic system to other parts of the body. If the doctor does not find cancer in the sentinel nodes then removing the remaining nodes is usually not necessary.
Dissection of the axillary lymph node: If a doctor finds cancer cells in the sentinel nodes, several lymph nodes in the axillary may be recommended for removal. That may prevent the spread of cancer.
Reconstruction: A surgeon can reconstruct the breast after mastectomy to make it look more natural. This can help a person cope with the effects of breast removal psychologically.
The surgeon can reconstruct the breast at the same time as or at a later date doing a mastectomy. We may be using a breast implant or tissue from another body part.
An individual may undergo radiation therapy about a month after surgery. Radiation includes targeting the tumor with controlled radiation doses which kill any remaining cancer cells.
A doctor may prescribe cytotoxic chemotherapy drugs that kill cancer cells if the risk of recurrence or spread is high. After surgery, doctors call it adjuvant chemotherapy, if a person has chemotherapy.
Sometimes, prior to surgery, a doctor may choose to administer chemotherapy to shrink the tumor and facilitate its removal. Doctors call this Chemotherapy Neoadjuvant.
Hormone blocking therapy
Doctors use hormone-blocking therapy to prevent the return of hormonally sensitive breast cancers after treatment. Hormone therapy may be used to treat cancers that are positive for the estrogen receptor (ER) and for the progesterone receptor (PR).
They usually administer hormone blocking therapy following surgery but may sometimes use it to shrink the tumor beforehand.
For people who are not suitable candidates for surgery, chemotherapy or radiotherapy, hormone blocking therapy may be the only option.
Doctors may recommend that a person undergo hormone therapy for 5–10 years following surgery. The treatment, however, will not affect cancers which are not hormone sensitive.
Examples of hormone blocking therapy medications may include:
- aromatase inhibitors
- ovarian ablation or suppression
- Goserelin, which is a luteinizing hormone-releasing agonist drug that suppresses the ovaries
Hormone treatment may affect fertility.
Targeted drugs can destroy specific types of breast cancer. Examples include:
- trastuzumab (Herceptin)
- lapatinib (Tykerb)
- bevacizumab (Avastin)
Breast and other cancer treatments can have severe side effects. People should discuss the potential risks with a doctor when deciding on a treatment, and look at ways of minimizing the side effects.
The outlook for a person with breast cancer is dependent on the stage. Early detection and care tend to result in a positive outlook.
A person receiving treatment for stage 0 or stage 1 breast cancer has a 99 percent chance of surviving for at least 5 years after being diagnosed, compared to women who do not have cancer, according to the ACS.
When breast cancer enters stage 4, the probability of survival for another 5 years will be decreased to around 27%.
Regular checks and screening may help in early detection of symptoms. Women should converse with a doctor about their options.
There are a number of different guidelines for how often women should be screening for breast cancer.
The American College of Physicists (ACP) recommends that women aged 40–49 with an average risk of breast cancer discuss with a doctor the benefits and risks of regular scans.
Women who have an average risk between the ages of 50 and 74 should undergo screenings every 2 years. Beyond the age of 75, doctors prescribe screenings only for women with a life expectancy of 10 years or more.
The ACS suggests that women of average risk can choose to have regular scans from 40 years of age onwards. Those not having will start screening at age 45 annually. If they reach age 55, they can decide to switch to screenings every other year.
Every year the American College of Radiologists suggests screenings beginning from age 40.
Notwithstanding the different guidelines, most experts agree that women should be discussing breast cancer screening with their doctors from age 40 onwards.
Breast cancer is not stopped. Many lifestyle choices, however, can significantly reduce the risk of breast cancer, as well as other forms.
- avoiding excessive alcohol consumption
- following a healthful diet containing plenty of fresh fruit and vegetables
- getting enough exercise
- maintaining a healthy body mass index (BMI)
Women should consider their breastfeeding choices and post-menopause use of HRT, as these can also increase the risk.
Preventive surgery is also an option for high risk women with breast cancer.
Which other cancers are common in women?
Other than skin cancer, the cancers that most often affect women include:
- lung cancer
- colorectal cancer
- uterine cancer
- thyroid cancer
- endometrial cancer
- cervical cancer
- ovarian cancer
Answers represent the views of our experts in medicine. All material is purely educational, and the medical advice should not be considered.