When malignant cancer cells form and grow within a person’s breast tissue, breast cancer occurs. Although it is the most commonly diagnosed cancer in American women, breast cancer can impact people of all genders. The American Cancer Society estimates that over 280,000 women and over 2,600 men will be newly diagnosed with invasive breast cancer in 2021 — and about 43,000 women and 530 men will die from breast cancer.
Here, we’ll provide an overview of breast cancer — from the different types to risk factors, symptoms and treatments — to give you a better picture of the disease and its impacts.
Types of Breast Cancer
Breast cancer is a malignancy in which the cells of the breast divide and grow at a faster-than-typical rate and can, over time, form tumors in the breast. Without treatment, malignant tumors can spread to other parts of the body.
While most breast cancers start in the milk ducts, some malignancies form first in the glandular tissue. Moreover, many tumors grow slowly: it may take as long as 10 years for a patient to be able to feel the tumor in their breast. However, in some instances, the tumor may be aggressive and grow at a much faster pace.
What you may not realize is that there are different types of breast cancer. The categorizations refer to the location of the cancer’s origin and whether it’s considered invasive or non-invasive. Invasive breast cancer refers to cancer cells that have traveled from their original location and have invaded surrounding tissue; in later stages, this type of cancer may spread to the lymph nodes or one’s organs. On the other hand, non-invasive cancers, sometimes referred to as “carcinoma in situ,” are confined to the point of origin and have not spread to otherwise healthy tissue.
With this in mind, types of breast cancer include:
- Ductal Carcinoma In Situ (DCIS): In this most common form of non-invasive breast cancer, making up around 1 in 5 new diagnoses, malignant cells develop inside the milk ducts and remain in place. Although DCIS is not a life-threatening cancer, it can increase your chances of developing invasive cancer later on.
- Lobular Carcinoma In Situ (LCIS): Like DCIS, LCIS remains within its place of origin and is non-life threatening. LCIS occurs when abnormal cells have developed in the milk-producing glands. LCIS is not thought of as a true form of breast cancer, but an instance of LCIS can put you at a higher risk for developing breast cancer in the future
- Invasive Ductal Carcinoma (IDC): This form of cancer, sometimes referred to as infiltrating ductal carcinoma, is the most common form of invasive breast cancer, affecting nearly 80% of all patients with invasive breast cancer. IDC begins in the milk ducts but, eventually, the cancer cells will break through the duct walls and attack the surrounding tissue.
- Invasive Lobular Carcinoma (ILC): ILC is the second-most common form of invasive breast cancer. In an instance of ILC, the cancer cells originate in the milk-producing glands, or lobules, and spread into nearby healthy tissue.
Other rare types of breast cancer include inflammatory breast cancer, angiosarcoma and Paget’s disease.
Symptoms Associated With Breast Cancer
In most cases, folks with early-stage breast cancer won’t exhibit signs or symptoms. In fact, cancer is often first detected by a routine mammography. Nonetheless, symptoms of breast cancer may include:
- A lump or mass felt in the breast
- An area of thickened tissue in the breast
- A change in the size of shape of your breast
- Swelling in or around the breast
- Irritation of the skin of the breast
- Dimpling of the skin of the breast
- Rashes on the breast
- Pain in the breast or nipple area
- Changes in the appearance of the nipple or surrounding skin.
- Discharge from the nipple
- Lump in the underarm area
Changes to the breast or surrounding area may be related to other medical conditions. Any unusual changes should be brought to your doctor’s attention immediately.
Diagnosis & Investigations
Diagnosis of breast cancer involves a physical examination by a doctor; use of imaging; and, often, a biopsy of the abnormal tissue. So, what are the specifics associated with these procedures?
- Mammogram: This procedure uses small amounts of x-ray beams to visualize the breast tissue.
- Ultrasound: This procedure uses a small probe placed on the skin of the breast to see the underlying tissue. Ultrasound may be more suitable for younger women with breast lumps
- Needle Aspiration: A small needle is used to take a sample of the abnormal breast cells, or if fluid is present (a cyst), a sample of fluid may be taken
- Needle Biopsy: A small core of tissue is removed with a needle, this allows for visualization of the cells
- Computed Tomography (CT) Scan: May be used to see if there is evidence of spread of breast cancer elsewhere in the body.
- Chest X-Ray: Used to look specifically at the lungs to see if there is any evidence of spread.
- Blood Tests: Used to check your blood counts, liver function, kidney function and sometimes to perform genetic testing.
When diagnosing breast cancer, your physician will try to determine its stage. Staging usually uses the TNM system which takes into account the size of the tumor (T), if it has spread to any lymph nodes (N) and if it has metastasized (M).
Tumour Size (T)
- T0 = primary tumor cannot be seen
- T1 = tumor is ≤ 20mm
- T2 = tumor is > 20mm but ≤ 50mm
- T3 = tumor is > 50mm
- T4 = tumor of any size which extends to the chest wall or skin
- N0 = no evidence of spread to lymph nodes
- N1 = metastases to e.g. 1–3 axillary lymph nodes
- N2 = metastases to e.g. 4–9 axillary lymph nodes
- N3 = metastases to e.g. ≥ 10 axillary lymph nodes or to infraclavicular lymph nodes
- M0 = no evidence of distant metastasis
- M1 = evidence of distant metastasis
Other factors, such as which receptors your type of cancer has on its cells, is also usually included in this formulation. Those other factors include:
- Human epidermal growth factor-2 (HER2)
- Estrogen (ER)
- Progesterone (PR)
These parameters are often combined to give an overall “stage” of the cancer:
- Stage 1: The tumor is small (
- Stage 2: The tumor measures 2–5cm, and there is evidence of nearby lymph nodes being affected, however there is no signs of spread to other places in the body
- Stage 3: The tumor measures 2–5cm and there is evidence that nearby lymph nodes and nearby structures are affected, but there is no sign of distant spread
- Stage 4: The cancer has spread to other parts in the body.
Note: This is not an exhaustive list of staging parameters as these can be much more complicated.
Grading of breast cancer is a measure of how “normal looking” the cells are at the time of examination. These grades include:
- G1 = low histological grade (favorable)
- G2 = intermediate histological grade (moderately favorable)
- G3 = high histological grade (unfavorable)
Note: Low-grade cells look more normal than high-grade cells.
Screening & Detection
Screening tests have the ability to detect cancer early on — when it’s most responsive to treatment. As such, people should perform self-breast exams and report any changes to their doctor.
Moreover, a baseline mammogram is recommended for all women at 40 years old; between the ages of 40 to 49, experts recommend that women schedule mammograms every one to two years based upon earlier results, risk factors, and so on. If any abnormalities are present, your doctor may send you for further testing to either diagnose or rule out cancer.
Causes & Risk Factors
There is no definitive cause for breast cancer, but many risk factors are associated with the disease, including:
- Having a family history of breast cancer (e.g. in your mother, sister or aunt)
- Increasing age
- Being overweight or obese
- Maintaining an unhealthy diet or lifestyle
- Early menstruation or late menopause
- The use of some types of birth control pills for more than 10 years
- Radiation to the chest to treat another condition at an early age
- Using hormone replacement therapy
Breast Cancer Treatment
There have been incredible advancements made in the treatment of breast cancer. As a result, the rate of deaths due to breast cancer has been on the decline. Treatment options may include surgery, radiation, chemotherapy and hormonal therapy. Moreover, your treatment plan will depend on the type and stage of breast cancer you have, as well as your medical history and personal preference.