Breast Cancer
Pathogenisis
Incidence/Prevalence
Risk Factors
Breast cancer is caused by a cluster of mutated cells rapidly growing due to damage to the DNA. These cells form a malignant tumor that starts in the breast. These cells will reproduce rapidly and can spread to other parts of the body if not treated. There are three hormones that will increase the rate of which these cells grow: estrogen, progesterone, and HER2/neu. Once the cancerous cells have fully developed they use the bloodstream to spread the cancer throughout the body. The immune system normally seeks out cancerous cells and cells with damaged DNA and destroys them. Breast cancer may be a result of the failure of such an effective immune defense and surveillance. These are several signaling systems of growth factors and other mediators that interact between stromal and epithelial cells; disrupting these may lead to breast cancer as well. There are several different types of breast cancer depending on where the tumor started to form and where it spreads. There are subtypes under that as well that classify by receptor cell status. There is ER-positive (ER+) which is where the receptors on the cancerous cells have estrogen receptors, PR-positive (PR+) where there are progesterone receptors, HR-positive (HR+) where there are estrogen and progesterone receptors, HR-negative (HR-) where there isn't any estrogen or progesterone receptors, and finally HER2-positive (HER2+) which have higher than normal levels of HER2+ protein. The HER2 protein helps the cancer cells grow and about 15% to 20% of all breast cancer diagnoses are HER2+. There are also four stages of breast cancer which are split into three different subsections: T, N, and M. To start, T is followed by a number from 0-4 this describes the main tumor's size and whether or not the tumor has moved to the skin or under the chest wall (0 being no evidence of main tumor to 4 where there is a tumor of any size growing into the chest wall or skin). The next stage is N which is also followed by a number from 0-3, which indicates if the cancer has spread to the lymph nodes, and if so, how many are affected. What we look for in the lymph nodes are deposits of cancer cells and their size, from which we determine what number they would fall under, where 0 is no cancer spread to the lymph nodes to 3 where cancer has at least spread to ten or more lymph nodes. Finally, M is followed by 0 or 1, which indicates whether the cancer has spread to distant organs such as lungs, livers, or bones: 0 meaning it has not spread and 1 meaning that is has.
Non modifiable
Treatments
The best way to treat breast cancer is with a combination of the following treatments. Depending on the age range there are different combinations that are favored. For younger adults a lumpectomy, neoadjuvant chemotherapy, and hormone therapy is the favored combination. For older adults breast cancer is primarily treated with surgery and radiation as chemotherapy might be to harsh.
Clinical manifestations
Some clinical manifestations are new painless lumps in the breast or underarm, thickening or swelling of the breast, redness of flakiness in the nipple area, pain in the general breast area, discharge from the nipple (blood or clear liquid), dimpling of skin, edema, and changes in the size or shape of either breasts. In all age groups any of these clinical manifestations are likely to be seen but lumps in the breast is least likely seen in younger women as this would mean they are in an advanced stage of breast cancer.
Diagnosis
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Resources
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BRCA mutation
Female sex
Being a female alone will increase one's chances of getting breast cancer, but men can also get breast cancer. Females have more estrogen hormones released giving them a higher chance of breast cancer.
modifiable
Obesity
Getting older
The risk for breast cancer increases with age as one are exposed to more estrogen, which is why breast cancer is usually diagnosed around age 50.
Older women who are less physically active and obese will have a higher risk for breast cancer than one that is healthy and active.
The most common risk factor is if the patents has a genetic mutation of either the BRCA1 or BRCA2 gene. This gene is sometimes called a tumor suppressor gene as this gene normally produces proteins that help repair damaged DNA, but if one were to inherit a mutation of this gene the probability for cancer to develop increases. Those with a family history of ovarian or breast cancer thus are at an increased risk of breast cancer as this BRCA gene can be passed down genetically. The lifetime risk for patients with the BRCA1 mutation is 65% to 81% and for the BRCA2 there is a 45% to 85%.
Taking hormones
Any form of hormone replacement therapy that contains estrogen or progesterone taken during menopause can increase the risk for breast cancer if taken for more than 5 years. Breast cancer related to hormone exposure are usually hormone receptor positive.
Drinking alcohol
Alcohol will increase the risks of getting breast cancer the more one drinks, as alcohol is a carcinogen. So drink minimal amount of alcohol is the best.
Dense breast
Dense breasts have more connective tissue than fatty tissue which makes it harder to see potential tumors on mammograms. Connective tissue may also produce growth factors that cause cells to divide and reproduce more than cells in fatty tissue do, promoting cancer growth.
Oral contraceptives
Taking oral contraceptives can increase the risk of getting breast cancer as all oral contraceptives have estrogen and/or progesterone. This is more estrogen and progesterone exposure to the body.
Surgery
environmental factors
Certain environmental factors such as ionizing radiation, pollutants, and chemicals (xenoestrogens) can be carcinogenic and therefore increase breast cancer risk.
Biopsy
Fine needle aspiration biopsy
core needle biopsy
image-guided biopsy
surgical biopsy
sentinel lymph node biopsy
A biopsy is when small pieces of breast tissue or fluid from the breast will be removed from the area where there is a suspected tumor. The specimen will then be taken to the lab to see if it contains cancerous cells. When analysing a biopsy we will be looking for tumor features, estrogen receptors and progesterone receptors, human epidermal growth factor receptor 2, and the tumor grade (slow growing or fast growing). There are many different types of biopsies depending on the type of needle and how and where the biopsy is taken.
Imaging tests
mammogram
ultra sounds
Magnetic resonance imaging (MRI)
Breast cancer is as of now the most common cancer among women making up 12.5% of all new annual cancer cases worldwide. About 13% of U.S. women are going to develop invasive ductal carcinoma which is the most common breast cancer sometime in the course of their life. In 2020, there were an estimated 3,886,830 women living with female breast cancer in the United States. Older women around the age of 50 and older are most likely to get diagnosed with breast cancer. Not many younger women get diagnosed with breast cancer and if so it's very rare. Only 4% of breast cancer diagnoses are women younger than the age of 40. Research has shown that non-hispanic white women and non-hispanic black women have the highest incidence of breast cancer. Black women are also most likely to pass away from breast cancer.
What it's like to live with breast cancer
A MRI is a body scan that will make detailed images by using magnets and radio waves to see the inside of the breast. MRIs can see skin lesions in the breast tissue that Mammograms might of missed. This is why MRIs are the best way for younger adults to identify breast cancer as they typically have denser breast tissue.
Ultrasounds use sound waves to identify lumps and tumors in breasts. This is the best way to diagnosis breast cancer with patients with dense breast tissue as abnormalities are more difficult to see on mammograms. This is also a good way for younger women to get diagnosed with breast cancer as younger patients tend to have dense breasts.
A mammogram is an x-ray picture of the breast. There are two different types of mammograms: screening and diagnostic. Screening mammograms are used to look for early signs of breast cancer for a patient who does not have signs or symptoms of breast cancer. If there are signs of breast cancer then a diagnostic mammogram is used to investigate suspicious breast cancer. The main difference between the two is that a diagnostic mammogram includes additional mammogram images.
When living with breast cancer patients must be constantly monitoring their health and staying as healthy as possible. Patients should fully understand their condition and think about solutions or decide on the course of action with treatments. Support from family or others is vital as this can be a difficult time for the patient. People with breast cancer should limit alcohol intake and stop smoking, as well as eat healthily and manage stress. It is important to go to the recommended medical checkups and tests to maintain on track with treatments. Regular exercise will help maintain strength and energy levels as well. There are many therapy options that are recommended for people with breast cancer such as physical therapy, occupational therapy, career counseling, pain management, nutritional planning, and emotional counseling. This can be a scary process for many patients as not only is being diagnosed with cancer terrifying, but altering one's lifestyle and habits can be jarring as well. Many go through a lot but don't let breast cancer define them and adapt to the new change.
Radiation
Chemotherapy
Hormone therapy
Biologic therapy
Bone marrow transplant
Centers for Disease Control and Prevention. (2023, July 25). How is breast cancer treated?. Centers for Disease Control and Prevention. https://www.cdc.gov/cancer/breast/basic_info/treatment.htm
Centers for Disease Control and Prevention. (2023, July 25). What are the symptoms of breast cancer?. Centers for Disease Control and Prevention. https://www.cdc.gov/cancer/breast/basic_info/symptoms.htm#:~:text=New%20lump%20in%20the%20breast,nipple%20area%20or%20the%20breast
Growth of cancer. National Breast Cancer Foundation. (2023, June 15). https://www.nationalbreastcancer.org/growth-of-breast-cancer/#:~:text=Damaged%20Cells,-Healthy%20cells%20are&text=Aggressive%20cell%20growth%20can%20form,other%20parts%20of%20the%20body
Leo and Gloria Rosen family. (2021, November 8). Stages of breast cancer: Understand breast cancer staging. Stages of Breast Cancer | Understand Breast Cancer Staging | American Cancer Society. https://www.cancer.org/cancer/types/breast-cancer/understanding-a-breast-cancer-diagnosis/stages-of-breast-cancer.html#:~:text=T1%20
Mayo Clinic Staff. (2023, August 25). Mammogram. Mayo Clinic. https://www.mayoclinic.org/tests-procedures/mammogram/about/pac-20384806
Cancer.Net Editorial Board (Ed.). (2023, June 8). Breast cancer - diagnosis. Cancer.Net. https://www.cancer.net/cancer-types/breast-cancer/diagnosis
Surgery as a treatment for breast cancer is where the tumor is surgically removed from the breast to prevent it from further spreading. There are two different surgical removals: lumpectomy (breast-conserving surgery) and mastectomy. Lumpectomy is where only the part of the breast containing cancerous cells is removed. This option is mainly for patients with early stages of breast cancer. Most will still need radiation after the surgery. A mastectomy is where the entire breast is removed including nearby tissues. Some may have either one breast removed or both which would be called a double mastectomy. This option might be better if the tumor is large in size.
Chemotherapy is an injection or oral medication that is used to shrink or kill the cancerous cells. There are two different types of chemotherapy: adjuvant(after surgery) and neoadjuvant(before surgery). Adjuvant chemotherapy is given after surgery to kill cancerous cells that might of been left behind after the surgery. Neoadjuvant chemotherapy might be given to shrink the tumor to lesson the amount that needs to be surgically removed. This is often used when the tumor is too large to be surgically removed. Neoadjuvant chemotherapy is favored among most young women with early stages of breast cancer.
Hormone therapy blocks the cancerous cells from receiving the hormones they need to grow, such as estrogen and progesterone, by using hormone blockers. This is recommended to patients with tumors that are hormone receptor-positive. This is usually taken for at least 5 years, as if it is taken for longer than it can cause the tumor to have a higher chance of coming back.
Biologic therapy (targeted therapy) works in two different ways: it helps the body's immune system to start attacking the cancerous cells or it makes the cancerous cells easier for the immune system to identify.
Bone marrow transplant is used to replenish the loss of healthy bone marrow due to other breast cancer treatments. These transplants are usually autologous meaning healthy bone marrow is taken from the patient before chemotherapy or radiation and then reinjected after the treatment. The reason for this procedure is that in some cases the doses of chemotherapy or radiation is so high that the bone marrows stem cells are either permanently damaged or completely destroyed.
Radiation uses high energy rays to kill the cancerous cells. By using images from a CT scan the radiation oncologist will then determine the dose of radiation needed for the cancerous area. This treatment usually takes around 3-6 weeks of daily treatment.
Adjuvant and neoadjuvant chemotherapy drugs
Anthracyclines (doxorubicin and epirubicin)
Taxanes (paclitaxel and docetaxel)
Capecitabine (Xeloda)
Cyclophosphamide (Cytoxan)
Carboplatin (Paraplatin)
Social determinants of health
Tamozifen
Toremifene (Fareston)
Fulvestrant (Faslodex)
Elacestrant (Orserdu)
The treatment for breast cancer is very expensive and tends to take a long time so low income families might not be able to afford the treatment needed. Many of these families are unable to receive proper insurance and healthcare so they avoid going to the doctor overall. This can cause the breast cancer to spread (metastasize)and become worse without the adequate amount of treatment. Most treatments (surgery, radiation, and chemotherapy) need to be done in the hospital under constant care. If the patient's place of residence is far from a hospital then they may be unable to get there. In some cases patients are unable to drive or don't have a vehicle. Lack of education can cause breast cancer to go on undiagnosed until it is too late as some patients might not know the signs and symptoms of breast cancer. Finally age is an important social determinant as some patients might not understand the importance of the treatments. This might also change how the treatments are given; instead of taking oral medication on their own they might be given IV by a nurse to insure that they are getting the proper medication at the right time.
Monoclonal antibodies
Trastuzumab (Herceptin)
Exposure to estrogen
Women are exposed to estrogen for majority of their life since they start puberty to when they start menopause; this exposure would last from around the age of 12 to 55. Prolonged exposure to estrogen will increase the risk for breast cancer. Estrogen can be prolonged by having an early puberty and/or a late menopause.
Family history
A patient's risk for breast cancer is increased if they have a family history of the disease.
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