Types of Breast Cancer
Types of Breast Cancer
Anjali Shah and Dr Lopamudra Das Roy
Published 2020
@BreastCancerHub, All Rights Reserved
Although Ductal Carcinoma is the most common breast cancer type, there are many other types of breast cancers that affect millions of men and women across the world. Let’s begin by exploring and highlighting the differences and similarities between these breast cancer types and comprehend each of them individually. [1]
Invasive Breast Cancer: These are the types of breast cancers that have broken out to invade the surrounding areas and nearby breast tissues. Many breast cancers are invasive, however there are subtypes to Invasive Breast Cancer as well [2] The two most common are:
Invasive Ductal Carcinoma:
Background: As previously mentioned, this is the most common type of breast cancer, and takes up 80% of Invasive Breast Cancer cases (8/10 Invasive breast cancer cases are Invasive Ductal Carcinoma). IDC occurs in the milk duct in the breast. Before it invades surrounding breast tissues it is known as Ductal Carcinoma in Situ. The difference between the two is that Ductal Carcinoma in Situ is still contained in the milk duct and has not invaded the surrounding breast tissue. Once Ductal Carcinoma in Situ breaks out through the walls of the milk duct and starts invading the bordering fibrous and fatty tissues it is called “Invasive Ductal Carc116
inoma”. Invasive Ductal Carcinoma, ican then spread throughout the rest of our body, through the lymph nodes and bloodstream [3]
Symptoms and Causes: Symptoms of IDC include, feeling of a breast lump or blood occurrence in the nipple discharge. The cause of IDC is yet to have been established however, the cancer begins in the milk ducts (Ductal Carcinoma in Situ) when the cells that line the milk duct starts growing and dividing uncontrollably [4] This results in a tumor caused by the buildup of excess cells that are rapidly being divided. Contributing factors to this could be your lifestyle, environment and genetic history. Rarest cases of IDC have been linked to mutations in BRCA1, BRCA2 and HER2 that can be inherited [5]
Diagnosis and Treatments: IDC is frequently discovered during mammograms. A mammogram is used to screen your breast. If bright white specks in clusters are highlighted in your mammogram then you will be recommended for further diagnosis and breast imaging by your radiologist. Treatments in most cases include lumpectomy and mastectomy. In lumpectomy, breast tissue is conserved and additional treatments such as radiation therapy. On the other hand, mastectomy is a breast-removing surgery. Other types of treatments include, Radiation therapy, and Hormone therapy [6]
Invasive Lobular Carcinoma:
Background Information: ILC, a type of invasive breast cancer, occurs in the milk-producing glands (lobules). Invasive in this case means that the cancer has broken out of the lobule and can start spreading to the lymph nodes and other areas in your body [7]
Symptoms and Causes: Invasive lobular carcinoma shows little to no symptoms in it’s earlier stages however, once it starts growing one may experience areas of breast thickening, swelling or difference in skin over the breast. Invasive lobular carcinoma begins due to mutations in the DNA that causes uncontrollable cell growth in the cells that line up the milk-producing glands [7]
Diagnosis and Treatment: Invasive Lobular Carcinoma is less likely to be found in diagnosis during mammograms and ultrasound that may be able to detect other types of cancers. When mammograms, and ultrasound results are inconclusive, doctors tend to perform MRI, which can detect cancers such as Invasive Lobular Carcinoma that are not found during other types of cancer screenings. Biopsy may also be recommended by the doctors if further abnormalities are found. Treatments in most cases include lumpectomy and mastectomy. Other types of treatments include, Radiation therapy ,and Hormone therapy. Sentinel lymph node biopsy, or axillary lymph node dissection [8]
Inflammatory Breast Cancer (IBC): Out of all the breast cancers, approximately 1-5% incorporate Inflammatory Breast Cancer. Although it is often a type of Invasive Ductal Carcinoma, it’s symptoms differ from most breast cancers [9] IBC develops fast and is often on the more aggressive side of most breast cancers. Usually, one cannot feel a lump or tumor in the breast as it is spread in certain areas throughout the breast [10]
Symptoms and Causes: Primary symptoms of IBC include unexplained appearances of rashes, swelling, redness or peeling on the breast and continuous itching.You may also notice changes in the appearance in nipples as they may appear inverted or even flattened.10 Breast swelling may be accompanied with red or purple emergence of rashes.9 Changes in breast cell DNA, that is usually located in the milk duct, is said to be the leading cause of IBC. Later, these cells divide rapidly and cause blocked lymphatic blood vessels. Risk factors include, being young (IBC affects women in their 40s and 50s), being black (black women a more likely to be affected by IBC than white women), and being obese (who are at a higher risk that those in their recommended weight range) [11]
Diagnosis and Treatment: Doctors proceed with diagnosis once they or the patients have noticed inflammatory breast cancer symptoms. It is likely that 2 or more types of breast screenings such as a diagnostic mammogram, breast ultrasound, or a biopsy will be performed by the doctors to identify occurrences of inflammatory breast cancer [12]. Chemotherapy is given to patients to begin the treatment journey and it is performed as a pre-surgical treatment to increase the success rate of cancer operations in IBC. It is often given in the form of drugs through veins, or in pill form, and sometimes both. Later one of the two surgeries, mastectomy or nearby lymph removal, are performed. Other types of treatments include, Radiation therapy ,and Hormone therapy [13].
Paget Disease of the Breast: Paget disease of the breast is a rarely occurring breast cancer that affects skin of the nipples or the surrounding area known as areola. People diagnosed with paget disease of the breast are also very likely (80-90%) to be diagnosed with either ductal carcinoma in situ, or invasive ductal carcinoma [14]
Symptoms and Causes: One may experience, Flaky, curtsy or scaly skin on your nipple (resembling eczema), continuous itching, redness, or a tingling sensation on the skin of the nipple/the areola, bloody nipple discharge, a flattened or inverted nipple, and thickening of breast skin. The main cause of Paget Disease of the Breast still remains unclear to the doctors, however the theory that it occurs in people from an underlying/history of ductal breast cancer [14]
Diagnosis and Treatment: Since people with Paget Disease of the Breast often have other forms of tumor such as ductal carcinoma in situ, doctors tend to perform breast imaging. Doctors may assess 2 or more types of breast screenings such as diagnostic mammogram, breast ultrasound, or a biopsy will be performed by the doctors to identify paget disease of the breast. Treatments in most cases include lumpectomy and mastectomy which is followed by whole-breast radiation therapy. The breast is also checked for invasive cancer, due to its frequent occurrence (80-90%) with paget disease of the breast [14].
Metastatic Breast Cancer: Metastatic breast cancer is often characterized as a stage 4 breast cancer, since it has spread throughout parts of our body, including lungs, liver, bones, and brain [15]. Cancer cells in metastatic breast cancer spread by invading near by cells, breaking through walls of lymph nodes and blood vessels which circulates them throughout the body.
Symptoms and Diagnosis: Symptoms in metastatic breast cancer based on affected areas of your body and far the cancer has progressed. Metastasis in the brain causes symptoms of pain, swelling, and fragile bones. Metastasis in the liver may cause symptoms of jaundice, abdominal pain, appetite loss, nausea, and vomiting, and rashes. Metastasis in the brain causes persistent headaches/migraines, vision disturbances, seizures, vomiting or nausea, and personality changes.15 Treatments include chemotherapy, radiation therapy, hormone therapy, breast surgery and biologic therapy [16].
Metaplastic Breast Cancer: Metaplastic breast cancer is a rare type of breast cancer which accounts for less than 1% of all breast cancer cases. Metaplastic breast cancer begins in the milk duct, very similarly to invasive breast cancer. However, the type of tumor cells being developed during metaplastic breast cancer is what makes it different from invasive breast cancer. Metaplastic breast cancer tumor cells seem to have had a change in their form (metaplasia) causing them to look similar to soft and connective tissue in the breast. [17].
Symptoms and Causes: Symptoms of metaplastic breast cancer include, breast pain, changes to the nipples such as dimpling, or inverted/flattened nipples, and lump or thickening of the breast [18]. It is believed that metaplastic breast cancer begins as invasive ductal carcinoma, which later goes through genetic mutations causing it’s cells to transform into tissue like cells [19].
Diagnosis and Treatment: Breast screening and biopsy will be performed to confirm occurrence of metaplastic breast cancer. Treatments for metaplastic breast cancer are similar to a combination of treatments for other types of breast cancers. This includes lumpectomy, mastectomy, radiation therapy, and systemic therapy. Examples of systemic therapy include endocrine therapy, chemotherapy, and therapy that targets HER2 protein [17].
Adenoid Cystic Breast Cancer: Adenoid cystic breast cancer is a rare subtype of invasive ductal carcinoma that accounts for less than 1% of all breast cancer cases. It’s cells are very similar to those found in salivary glands and saliva, when examined under the microscope. Symptoms of cystic breast cancer are similar to symptoms of invasive ductal carcinoma. Treatments include lumpectomy, mastectomy, radiation therapy, and systemic therapy. Examples of systemic therapy include endocrine therapy, chemotherapy, and therapy that targets HER2 protein [20].
Apocrine Breast Cancer: Apocrine breast cancer is a rare subtype of invasive ductal carcinoma that also begins in cells that line up the milk duct. What makes apocrine breast cancer different from other types of invasive ductal carcinoma, are it’s cells when examined under the microscope. Apocrine breast cancer cells look similar to those found in sweat glands in the underarm or groin area. Similar to metaplastic breast cancer it is believed that apocrine breast cancer cells have also gone through a change in form, known as metaplasia. Treatments include lumpectomy, mastectomy, radiation therapy, and systemic therapy. Examples of systemic therapy include endocrine therapy, chemotherapy, and therapy that targets HER2 protein [21]
Conclusion: Breast cancer research has yet to have become a field where enough outreach has been done, not only in developing countries but also developed countries such as the United States. We not only see ignorance of symptoms in women but also men due to societal judgements. It is important to fight these societal “standards” that stand in the way of breaking down the norms surrounding breast cancer. It’s important to fight together and to break down the stigmas surrounding breast cancer.
Word References:
In Situ: The word “In Situ” means “in original place”.3
Mammogram: A mammogram is used to screen your breat.6
Molecular Subtypes: Molecular subtypes are names given to breast cancer type based on genes the cancer expresses.
Lumpectomy: In lumpectomy, breast tissue is conserved and additional treatments such as radiation therapy.6
Mastectomy: Mastectomy is a breast-removing surgery.6
Radiation therapy: High-energy beams are used to kill abnormal cells.6
Hormone Therapy: Which is used only against cancers that grow in response to hormones, hormone therapy is used to prevent hormones from reaching cancer cells.6
Biopsy: It is the removal of a sample tissue that can be examined under the microscope to find further abnormalities in the breast tissue. 8
Ultrasound: A form of breast screening where pictures of your breast are created through the use of sound waves. 8
MRI: Another form of breast screening that uses a magnetic field to create pictures of your breast.8
Axillary lymph node dissection: It is performed to determine and remove lymph nodes that might be affected by the spread of cancer.
Lobules: Milk-producing glands. 8
Areola: The darker circle of skin around the nipple.14
Systemic therapy: It is used to prevent the disease from coming back or spreading to another part of the body.18
Citations
“Types Archives.” National Breast Cancer Foundation, www.nationalbreastcancer.org/types-of-breast-cancer/.
“Invasive Breast Cancer (IDC/ILC): Types of Invasive Breast Carcinoma.” American Cancer Society, www.cancer.org/cancer/breast-cancer/understanding-a-breast-cancer-diagnosis/types-of-breast-cancer/invasive-breast-cancer.html.
“Invasive Ductal Carcinoma (IDC).” National Breast Cancer Foundation, 19 Sept. 2019, www.nationalbreastcancer.org/invasive-ductal-carcinoma.
“Ductal Carcinoma in Situ (DCIS).” Mayo Clinic, Mayo Foundation for Medical Education and Research, 20 May 2020, www.mayoclinic.org/diseases-conditions/dcis/symptoms-causes/syc-20371889.
“Causes of Invasive Ductal Carcinoma.” Moffitt Cancer Center, moffitt.org/cancers/invasive-ductal-carcinoma/diagnosis/causes/.
“Ductal Carcinoma in Situ (DCIS).” Mayo Clinic, Mayo Foundation for Medical Education and Research, 20 May 2020, www.mayoclinic.org/diseases-conditions/dcis/diagnosis-treatment/drc-20371895.
“Invasive Lobular Carcinoma.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 23 May 2020, www.mayoclinic.org/diseases-conditions/invasive-lobular-carcinoma/symptoms-causes/syc-20373973?mc_id=google.
“Invasive Lobular Carcinoma.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 23 May 2020, www.mayoclinic.org/diseases-conditions/invasive-lobular-carcinoma/diagnosis-treatment/drc-20373979.
“Inflammatory Breast Cancer: Details, Diagnosis, and Signs.” American Cancer Society, www.cancer.org/cancer/breast-cancer/understanding-a-breast-cancer-diagnosis/types-of-breast-cancer/inflammatory-breast-cancer.html.
“Inflammatory Breast Cancer (IBC).” National Breast Cancer Foundation, 19 Sept. 2019, www.nationalbreastcancer.org/inflammatory-breast-cancer.
“Inflammatory Breast Cancer.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 14 July 2020, www.mayoclinic.org/diseases-conditions/inflammatory-breast-cancer/symptoms-causes/syc-20355413.
“Inflammatory Breast Cancer Diagnosis.” Moffitt Cancer Center, moffitt.org/cancers/inflammatory-breast-cancer/diagnosis/.
“Inflammatory Breast Cancer.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 14 July 2020, www.mayoclinic.org/diseases-conditions/inflammatory-breast-cancer/diagnosis-treatment/drc-20355417.
“Paget Disease of the Breast: Nipple Cancer.” American Cancer Society, www.cancer.org/cancer/breast-cancer/understanding-a-breast-cancer-diagnosis/types-of-breast-cancer/paget-disease-of-the-nipple.html.
“Metastatic Breast Cancer.” National Breast Cancer Foundation, 22 Sept. 2019, www.nationalbreastcancer.org/metastatic-breast-cancer.
Metastatic Breast Cancer Treatment & Prognosis: Johns Hopkins Breast Center, 31 Oct. 2017, www.hopkinsmedicine.org/breast_center/breast_cancers_other_conditions/metastatic_breast_cancer.html.
Potter, Michelle. Metaplastic Breast Cancer - Johns Hopkins Kimmel Cancer Center, 2 Apr. 2018, www.hopkinsmedicine.org/kimmel_cancer_center/cancers_we_treat/breast_cancer_program/treatment_and_services/rare_breast_tumors/metaplastic_breast_cancer.html.
“Metaplastic Breast Cancer.” Breast Cancer Now, 24 June 2020, https://breastcancernow.org/information-support/facing-breast-cancer/diagnosed-breast-cancer/primary-breast-cancer/metaplastic-breast-cancer
“Pathology: Cause & Effect.” Metaplastic Breast Cancer Global Alliance, 30 Oct. 2018, www.mpbcalliance.org/metaplastic-breast-cancer-pathology/.
Potter, Michelle. Adenoid Cystic Breast Canter: Johns Hopkins Kimmel Cancer Center, 2 Apr. 2018, www.hopkinsmedicine.org/kimmel_cancer_center/cancers_we_treat/breast_cancer_program/treatment_and_services/rare_breast_tumors/adenoid_cystic_breast_cancer.html.
Potter, Michelle. A[Pcrome Breast Cancer - Johns Hopkins Kimmel Cancer Center, 2 Apr. 2018, www.hopkinsmedicine.org/kimmel_cancer_center/cancers_we_treat/breast_cancer_program/treatment_and_services/rare_breast_tumors/apocrine_breast_cancer.
Sara Fazio, MD. “Untangling the Non-Invasive Breast Cancer Controversy.” Harvard Health Blog, 17 Sept. 2015, www.health.harvard.edu/blog/untangling-the-non-invasive-breast-cancer-controversy-201509188293.
Conway, Josh, “Chronic Inflammation Leads to Toxic NET Buildup.” Lifespanio, 26 Mar. 2019, www.lifespan.io/news/chronic-inflammation-leads-to-toxic-net-buildup/.
“Cancer and Coronavirus: Coping with a Double Challenge.” UICC, 2 Feb. 2020, www.uicc.org/news/cancer-and-coronavirus-coping-double-challenge.
Helsinki Uni. “Researchers Discovered a New Targetable Vulnerability in Breast Cancer Cells.” EurekAlert!, www.eurekalert.org/pub_releases/2019-03/uoh-rda032919.php.