Breast cancer is a disease in which the breast cells grow uncontrollably. There are different types of breast cancer based on the breast cells that turn malignant. Breasts are made of three main parts—connective tissues, ducts, and lobules. Lobules are the mammary glands that produce milk, and the connective tissue is made of fibrous and fatty tissues that hold the breast together. Most forms of breast cancer begin at the lobules and ducts.

Breast cancer is said to have metastasized if it spreads to other parts of the body through the lymph vessels and lobules. The symptoms of breast cancer are based on its stages, and the signs of metastatic breast cancer signs are visible in stage IV.

Stage-based symptoms of breast cancer

Stage 0
In this stage, there is no indication of the tumor spreading to other parts of the breast or other parts of the body. This stage of cancer is non-invasive and is considered to be a precancerous condition that requires close observation but no treatment. Unlike the signs of metastatic breast cancer, breast cancer in stage 0 is difficult to detect as there are no major physical changes visible. Self-examination and routine screening can lead to an early diagnosis. One of the less worrying factors about stage 0 breast cancer is that the disease is treatable at this stage.

Stage I
It is the earliest stage of invasive breast cancer. The tumor in stage I breast cancer measures up to 2 centimeters. The malignancy (cancer) has not yet spread to the lymph nodes, but the cancerous cells have spread beyond the original location to the surrounding breast tissue. In stage I, the tumor is small and hard to detect. There are two substages of stage I based on the size of the tumors:

• Stage IA: This stage is characterized by a tumor that measures approximately 2 centimeters (about the size of shelled peanut or pea) but has not spread outside the breast.
• Stage IB: A person suffering from this stage of cancer may have small clusters of cancer cells, not more than 2mm in size, in the lymph nodes.

According to studies, the survival rate for Stage IA breast cancer might be slightly higher than Stage IB.

Stage II
This type of cancer is also referred to as invasive breast cancer. The size of the tumor in stage II measures between 2-5cm, and there are chances that cancer has spread to the lymph nodes under the arms on the same side of the original location of cancer. This stage is a slightly more advanced form of the disease and indicates that cancer cells have spread beyond the original location and into the surrounding breast tissue. Stage II tumors can be easily detected through self-examination as a person might feel a hard lump in the breast. It is important to screen such tumors as it can lead to an early diagnosis. Stage II is further divided into two subcategories:

• Stage IIA: The tumor in stage IIA breast cancer is 2-5cm in size, and cancer may or may not have spread to the axillary lymph nodes.
• Stage IIB: The tumor in this stage is larger than 5cm, and the malignancy may or may not have spread to the axillary lymph nodes.

Stage III
This stage is also called locally advanced breast cancer. It is characterized by a tumor that is more than two inches in diameter. Stage III breast cancer can be termed as extensive as it has spread to the lymph nodes or other tissues near the breast. But in this stage, breast cancer has not yet spread or metastasized to different parts of the body. Stage III breast cancer is divided into three substages:

• Stage IIIA: In this substage, cancer may be found in axillary lymph nodes and not in the breast or vice versa. The tumor’s size can vary from 2-5cm in size, and it may be attached to other structures or may have spread to the lymph nodes near the breastbone.
• Stage IIIB: The stage is characterized by the spread of the cancerous tumor to the chest wall and the skin of the breast. Cancer that has spread to the skin of the breast is referred to as inflammatory breast cancer.
• Stage IIIC: The cancer cells or tumors in this stage may not be present in the breast but have spread to the chest wall or the skin of the breast. It might also be present in the lymph nodes and collarbone.

Stage IV
This stage is also referred to as metastatic breast cancer, and in this stage, the signs of malignancy can be seen in the internal mammary lymph nodes and distant parts of the body. The affected areas include bones, brains, lungs, and liver. The doctors may use the TNM system to describe the extent of metastatic breast cancer based on the signs. Here is a brief explanation of the TNM system:

• T: Cancer will be classified based on the size and extent of the primary tumor.
• N1: It indicates that cancer has spread to the lymph nodes.
• M1: It indicates that cancer has spread to other sites in the body.

The signs of metastasized breast cancer include pitted skin, flattening of nipples, and redness and swelling of the breast. When breast cancer moves to the other areas of the body, it leads to symptoms like weakness or numbness, consistent dry cough, chest pain, loss of appetite, seizures, loss of balance, vision problems, bloating, diarrhea, jaundice, and other organ-specific diseases.

Recurrent breast cancer
This type of breast cancer occurs when the disease returns after the initial treatment. Most recurrences appear within two to three years of treatment. There are many cases in which a patient experiences signs of metastatic breast cancer within the first five years of treatment. So, it is necessary to keep a close watch on any irregular symptoms and consult an oncologist to avoid delay in treatment.