Breast cancer refers to a disease in which the breast cells, in either or both breasts, grow in an unchecked manner. This rapid division of cells results in a breast cancer tumor.
Breast carcinoma can initiate in three parts: the lobules or glands producing milk, the ducts or tubes, which assist in delivering milk to the nipples, and the connective tissues surrounding the ducts and lobules.
As the name suggests, this carcinoma starts in the breast tissue and can easily invade the tissues surrounding the breasts. In addition, cancer can spread to other parts of the body, forming new tumors. This spreading of tumors to other body parts is called metastasis.
The common symptoms of cancer of the breast include breast lumps, a change in breast size, and changes in the breast skin.
As far as its prevalence is concerned, breast carcinoma is counted among the most common cancers across the globe. In India, it is the top most common cancer among women.
Although rare, men can also develop this type of cancer.
Cancer can start in different parts of the breast, and as per the location of the tumor, the types of breast cancer are classified.
The different parts of the breasts where cancer can start are the lobules, ducts, nipple, stroma, blood vessels, and lymph vessels.
Breast lobules are the glands located inside the breast tissue that are responsible for producing breast milk. The cancer that originates in the lobules is called lobular cancer.
Breast ducts are tiny canals that are responsible for carrying milk to the nipple from the lobules. Carcinoma that starts in the ducts is called ductal cancer.
The nipple is the opening in the breast skin where the ducts join together to form bigger ducts to ensure the smooth release of breast milk. The cancer that forms in the nipple is called Paget disease of the breast. This is a rare form of breast carcinoma.
Fat and connective tissue, or stroma, is responsible for offering support and protection to the breast tissue. The cancer that starts in the stroma is called a phyllodes tumor.
Blood vessels and lymph vessels are essential parts of the breast. The blood vessels are responsible for carrying nutrients and oxygen to the breast tissue, while the lymph vessels assist in removing any waste and additional fluids from the breasts. The cancer that initiates in the vessel lining is called angiosarcoma.
The two broadly available types of breast cancer include invasive breast cancer and non-invasive breast cancer. The specific location of these cancers and their ability to spread are primarily used to categorize the following different types of breast cancer.
Infiltrating (invasive) ductal carcinoma is one of the most common types of breast cancer, where abnormal cancerous cells initiate in the breast's milk ducts and invade the surrounding tissues. With time, this invasive breast carcinoma may spread to the lymph nodes or bloodstream. Also, infiltrating ductal carcinoma is one of the types of breast cancer that commonly affects men.
There are some rare types of invasive ductal carcinoma, which include:
Medullary carcinoma is a rare subtype of invasive breast cancer that forms in the breast's milk duct cells.
Metaplastic carcinoma is a rare subtype of aggressively growing infiltrating ductal carcinoma. Under a breast cancer imaging test, the metaplastic carcinoma cells appear to be a mixture of breast cells and other cell types, such as bone, muscle, skin, and cartilage.
Mucinous or colloid carcinoma is another rare type of invasive breast cancer that starts in the milk ducts and then moves further to other healthy body tissues. In this carcinoma, the cancerous cells form in the mucin, a major component of mucus.
Papillary carcinoma is a very rare type of invasive breast carcinoma that is defined by the growth of uniquely shaped projections known as papillae.
Another rare type of invasive breast carcinoma is tubular carcinoma. These cancerous cells possess tube-like structures and are quite small in size. This cancer also develops in the milk ducts and then moves to other tissues.
Ductal carcinoma in situ implies a non-invasive breast carcinoma, which develops when the cells present in the milk ducts' lining become cancerous. However, this type of cancer does not spread to the surrounding tissues.
Infiltrating invasive lobular carcinoma is a breast tumor type that starts in the lobules or glands that are responsible for producing milk in the breast. It is an invasive cancer that can easily invade nearby tissues.
Lobular carcinoma in situ is not classified as cancer, but a patient diagnosed with this condition has a high risk of developing breast carcinoma. As per experts, lobular carcinoma in situ implies a situation where the cells in the breast lobules become abnormal.
When a breast tumor does not show any receptors for the three proteins—progesterone, estrogen, and HER2/ne—which are usually found in carcinoma of the breast, it is termed a triple-negative breast cancer.
Inflammatory breast cancer is an aggressive found mainly in the lobules or ducts. Also, this form of cancer does not possess any receptors for progesterone, estrogen, or HER2/neu.
Paget's disease of the breast is a type of carcinoma that gets formed in the areola, or pigmented skin, which surrounds the nipples.
The breast cancer stages are classified according to aspects such as the location and size of the tumor, the extent of cancer spread in the body, the tumor grades, and the presence or absence of specific biomarkers.
Stage 0 breast cancer is also referred to as ductal carcinoma in situ and is the earliest stage. At this stage, the cancer is limited to the milk ducts only and has not spread to the nearby tissues.
Stage 1 breast cancer means the tumor is localized and its size is smaller than or equivalent to 2 centimeters. Also, the cancerous cells at this stage do not spread to the lymph nodes or other organs.
At a more advanced stage, at stage 2, the tumor gets larger than 2 centimeters and may begin spreading to the lymph nodes but not to other body parts.
At this stage, the tumor has grown in size, i.e., more than 5 centimeters, and is spreading to the lymph nodes and maybe other nearby organs.
Stage 4 is the final and most advanced stage, when cancer metastasizes to the lymph nodes and prominent body organs, such as the lungs, bones, or liver.
Being diagnosed with breast carcinoma can cause immense distress for patients. However, it is important to be aware of the different risk factors that are associated with breast cancer and the early symptoms of this disease. This helps in the early detection and timely treatment of this disease.
Early detection and timely intervention play a pivotal role in successfully managing breast carcinoma. Therefore, it is important for women to be mindful of the different breast cancer symptoms and see a doctor when they come across something alarming.