There are numerous forms of breast cancer and numerous methods to define them. It’s easy to become perplexed after receiving a breast cancer diagnosis. The exact cells in the breast that are impacted determine the type of breast cancer. The majority of breast cancers are carcinomas, which are tumours that begin in the epithelial cells that line the organs and tissues of the body. When carcinomas originate in the breast, they are frequently a kind known as adenocarcinoma, which begins in cells in the ducts (milk ducts) or lobules (milk-producing glands). Breast cancer can start in a variety of places, including the ducts, lobules, and, in some circumstances, the tissue in between. This part will teach you about the various types of breast cancer, such as non-invasive, invasive, and metastatic breast cancers, as well as the intrinsic or molecular subtypes of breast cancer. The type of breast cancer might also indicate whether or not the cancer has spread. In situ breast cancer (ductal carcinoma in situ, or DCIS) is a type of cancer that begins in a milk duct but does not spread to the rest of the breast tissue.
The phrase invasive (or infiltrating) breast cancer refers to any type of breast cancer that has spread (invaded) into the surrounding breast tissue.
Ductal cancer in situ (DCIS)
Ductal carcinoma in situ (DCIS; also known as intraductal carcinoma) is a type of non-invasive or pre-invasive breast cancer. DCIS can also be referred to as intraductal carcinoma or stage 0 breast cancer. DCIS is a type of breast cancer that is non-invasive or pre-invasive. This suggests that the cells lining the ducts have transformed into cancer cells, but they have not migrated through the duct walls into surrounding breast tissue. Because DCIS has not expanded into the surrounding breast tissue, it cannot spread (metastasize) to other parts of the body. DCIS, on the other hand, can sometimes progress to aggressive malignancy. At that point, the cancer had progressed from the duct into adjacent tissue and could have spread to other sections of the body.
Because there is no way to predict which DCIS will progress to invasive cancer and which will not, practically all women with DCIS will be treated.
Invasive breast cancer (IDC/ILC) is a type of cancer that spreads throughout the body.The majority of breast cancers are invasive, but there are various forms of invasive breast cancer. Invasive ductal carcinoma and invasive lobular carcinoma are the two most prevalent types.Invasive breast cancer also includes inflammatory breast cancer and triple negative breast cancer.
Invasive (infiltrating) ductal carcinoma (IDC)
This is the most prevalent form of breast cancer. Invasive (or infiltrating) ductal carcinomas account for approximately 8 out of 10 invasive breast cancers (IDC).IDC begins in the cells that border the breast milk duct. The malignancy then bursts through the duct wall and spreads to the adjacent breast tissues. It may be able to spread (metastasize) to other parts of the body through the lymph system and bloodstream at this point.
Invasive lobular carcinoma (ILC)
An invasive lobular carcinoma accounts for approximately one-tenth of all invasive breast cancers (ILC).ILC begins in the glands that produce milk (lobules). It, like IDC, has the ability to spread (metastasize) to other regions of the body. On physical examination and imaging, such as mammograms, invasive lobular carcinoma may be more difficult to detect than invasive ductal carcinoma.
Triple negative breast cancer
TNBC accounts for roughly 10-15% of all breast cancers. The phrase triple-negative breast cancer refers to cancer cells that lack oestrogen and progesterone receptors and produce insufficient amounts of the protein HER2.These malignancies are more frequent in women under the age of 40, African-American women, and women with a BRCA1 mutation.Triple-negative breast cancer is distinct from other types of invasive breast cancer in that it grows and spreads more quickly, has fewer treatment options, and has a poor prognosis (outcome).
Inflammatory Breast Cancer
Inflammatory breast cancer (IBC) is uncommon, accounting for just 1–5% of all breast cancers. Although it is frequently classified as an invasive ductal carcinoma, it differs from other forms of breast cancer in terms of symptoms, prognosis, and treatment.IBC has inflammatory symptoms such as swelling and redness, although infection or damage do not cause IBC or the symptoms. IBC symptoms are caused by cancer cells blocking lymph veins in the skin, giving the breast a “inflamed” appearance.Symptoms include breast swelling, purple or red skin, and dimpling or thickening of the breast skin, which may look and feel like an orange peel. Even if a lump is present, you may not notice it. If you have any of these symptoms, it does not mean that you have IBC, but you should see a doctor right away.
Paget Disease of the Breast
Paget disease of the breast is a rare kind of breast cancer that affects the nipple and areola skin (the dark circle around the nipple). In most cases, Paget disease affects only one breast. It is typically observed in conjunction with either ductal carcinoma in situ (DCIS) or infiltrating ductal carcinoma (IDC) in 80-90 percent of cases (invasive breast cancer)The nipple and areola skin is frequently crusty, scaly, and red. Blood or yellow fluid may be oozing from the nipple. The nipple might appear flat or inverted at times. It may also burn or itch. Your doctor may first try to treat this as eczema, and if it does not improve, he or she may recommend a biopsy.
Angiosarcoma is a rare cancer that develops in the cells that lining blood and lymph arteries. It is frequently a side effect of earlier breast radiation treatment. It can occur 8-10 years after receiving breast radiation treatment.Angiosarcoma can result in skin changes such as purple nodules and/or a lump in the breast. It can also occur in the affected arms of lymphedematous women, but this is uncommon. (Lymphedema is swelling that can develop after breast cancer surgery or radiation therapy.)
Stages of Breast cancer
Stages is a method of defining the extent of breast cancer, including the size of the tumour, if it has progressed to lymph nodes, whether it has moved to distant parts of the body, and what biomarkers are present. Staging can be performed either before or after a patient has surgery. Doctors utilise diagnostic tests to determine the stage of cancer, therefore staging may not be complete until all tests are completed. Knowing the stage assists the doctor in determining the best course of treatment and can help estimate a patient’s prognosis, or possibility of recovery, This is the breast cancer stages.
TNM staging system
The TNM system is the most commonly used method by clinicians to describe the stage. Doctors use diagnostic test and scan results to address the following questions:
- Tumour (T): How large is the primary tumour in the breast? What are its biomarkers?
- Node (N): Has the tumour spread to the lymph nodes? If so, where, what size, and how many?
- Metastasis (M): Has cancer spread to other parts of the body?
Breast cancer is classified into five stages: stage 0 (zero), which is non-invasive ductal carcinoma in situ (DCIS), and stages I through IV (1–4), which are used for invasive breast cancer. The stage provides a common language for doctors to describe the cancer so that they can collaborate to determine the best treatments.Clinical and pathological staging are both possible. Clinical staging is determined by the results of pre-surgery diagnostics such as physical examinations, mammograms, ultrasounds, and MRI scans. Pathological staging is determined by what is discovered during breast tissue and lymph node removal surgery. Typically, the results are available few days following surgery.
The “T” plus a letter or number (0 to 4) used in the TNM system is used to describe the size and location of the tumour. Tumours are measured in millimetres (cm). A centimetre is roughly the width of a normal pen or pencil.
Stages can also be subdivided into smaller groups to assist describe the tumour in greater detail. Specific tumour stage information is provided below.
T0 (T plus zero): There is no evidence of cancer in the breast
Tis: . The malignancy is contained to the ducts of the breast tissue and has not spread to the surrounding tissue. There are two forms of breast cancer in situ
Tis (DCIS): DCIS is a non-invasive cancer that, if left untreated, can progress to invasive breast cancer. DCIS indicates that cancer cells have been discovered in the breast ducts but have not spread beyond the layer of tissue where they began.
Tis (Paget’s): Paget disease of the nipple is a rare form of early, non-invasive cancer that exclusively affects the nipple’s skin cells. Paget disease is sometimes linked to invasive breast cancer. If invasive breast cancer exists, it is classed based on the stage of the invasive tumour.
T1: The tumour in the breast is 20 millimetres (mm) or smaller in size at its widest area. This is a little less than an inch. This stage is then broken into 4 substages depending on the size of the tumor:
- T1mi is a tumour that is 1 mm or smaller.
- T1a is a tumour that is larger than 1 mm but 5 mm or smaller.
- T1b is a tumour that is larger than 5 mm but 10 mm or smaller.
- T1c is a tumour that is larger than 10 mm but 20 mm or smaller.
T2: The tumor is larger than 20 mm but not larger than 50 mm.
T3: The tumor is larger than 50 mm.
T4: The tumor falls into 1 of the following groups:
- T4a means the tumor has grown into the chest wall.
- T4b is when the tumor has grown into the skin.
- T4c is cancer that has grown into the chest wall and the skin.
- T4d is inflammatory breast cancer.