According to the World Health Organization (WHO), lung cancer is the leading cause of cancer deaths worldwide in men, while breast cancer is the leading cause of death in women. [1,2] Since 2008, worldwide breast cancer incidence has increased and it affects around 2.1 million women every year.  Studies showed that in every four minutes, a woman is diagnosed with breast cancer, globally. As per the Indian Council of Medical Research (ICMR) data, around 1, 00,000 new breast cancer patients are diagnosed every year in India. [3,4]
About breast cancer
Breasts are made up of three main parts: lobules, ducts, and connective tissues (which consists of fibrous and fatty tissue). Lobules are the glands that produce milk, while ducts are thin tubes that carry milk to the nipple. The connective tissue provides support and holds everything together in shape.
Breast cancer is caused by abnormal growth and division of cells in the breast. They can begin either in the cells of the lobules or ducts. Breast cancer mostly occur in women, but men can also get breast cancer.
Breast cancers are of different types and the common ones include ductal carcinoma in situ (DCIS) and invasive carcinoma. Other less common types of breast cancer are Paget’s disease, phyllodes tumors, angiosarcoma and inflammatory breast cancer.
Signs and symptoms of breast cancer
The most common symptom of breast cancer is a new soft lump or mass in the breast or underarm. Additionally, it may also cause:
- Swelling of the breast
- Pain in the breast region
- Inverted nipple
- Change in the nipple or breast skin
- Irritation or dimpling of the breast skin
- Nipple discharge other than the breast milk
Causes and Risk Factors
The exact cause of breast cancer is not clear. However, some of the following factors may increase the risk of developing breast cancer:
Non-modifiable risk factors:
- Women gender
- Family history
- Breast density
Modifiable risk factors:
- Alcohol consumption
- Sedentary lifestyles
Breast cancer diagnosis is necessary when suspicious lumps or nodules shows up during a clinical or self-examination. Initially, the symptoms, medical history, and family history of the patient are reviewed. A physical examination is done to identify lumps or variations in the breasts.
To confirm the diagnosis, following tests are recommended.
- Imaging tests
Imaging tests help to diagnose the stage and extent of breast cancer. These tests include:
- Mammograms: Mammograms are low-dose x-rays that are used to screen breast cancer. It helps in diagnosing and locating the lumps and any other breast abnormalities.
- Breast ultrasound: It uses sound waves to create internal images of breasts, showing any lumps or abnormalities. It helps to distinguish between a solid mass, which may be cancer and a non-cancerous fluid-filled cyst.
- Breast MRI: It uses powerful magnetic fields to create images of the breast. It helps in identifying breast lumps that are not visible with other imaging tests especially in women with dense breast tissue.
- Scintimammography: It is a type of nuclear medicine imaging test that helps determine the extent of breast cancer that has already been diagnosed. It also helps to decide whether a biopsy or additional follow-up tests are necessary.
A sample of breast tissue is collected and examined in laboratory to determine any abnormalities. There are different kinds of biopsies based on the technique used to collect the tissue sample, such as fine-needle aspiration, core biopsy, open biopsy etc.
Stages of breast cancer:
The cancer staging is done using TNM system. It provides detailed information about:
- Tumour (T): Whether the primary tumour has grown through the breast
- Node (N): Whether the cancer has spread to the lymph nodes surrounding the breast
- Metastasis (M): Whether the cancer has spread to distant parts of the body.
Based on the TNM staging, breast cancer has the following stages:
- Stage 0a/0is: Cancer cells are located only in the ducts of the breast tissue and have not spread to the surrounding tissue of the breast.
- Stage I: Tumors are either small, invasive, and have not spread to the lymph nodes or if have spread to the lymph nodes and the cancer in the lymph node is larger than 0.2 mm in size.
- Stage II: Tumors are between 20-50mm in size and may have spread to the axiliary lymph nodes or a tumor larger than 50mm and no lymph nodes are involved.
- Stage III: Tumor is larger than 50mm and has spread to 4 to 9 axiliary lymph nodes or to internal mammary lymph nodes. It may have spread to chest wall or skin.
- Stage IV: The tumor can be any size and has spread to distant parts of the body like lung, liver, and bones.
Treatment for breast cancer
The main aim of the treatment is to remove as much as cancer possible and to prevent the recurrence. Based on the type, size, and extent of cancer, the treatment team will recommend the following treatment option:
Breast cancer surgery:
The surgery involves removal of the tumor and some surrounding healthy tissue. It is mainly recommended for early stage cancer with smaller tumor.
Types of surgery include the following:
- Lumpectomy: The tumor and some surrounding tissue is removed while leaving the rest of the breast intact. For invasive cancer, radiation therapy is recommended after the surgery to remove the remaining cancer cells.
- Mastectomy: It involves removal of all the breast tissue. In some cases, double mastectomy is required, in which both breasts are removed.
- Sentinel node biopsy: This procedure involves locating the sentinel lymph nodes and their removal. These nodes are sent to the laboratory for further examination. This procedure is recommended if the cancer has spread beyond the primary tumour.
- Axillary lymph node dissection: It involves removal of lymph nodes from the armpit. This procedure is recommended if one or more sentinel lymph nodes contain cancer.
- Breast reconstruction: It is done to rebuild the shape of breast after mastectomy.
It involves delivering high-energy radiation beams to shrink and destroy tumors. It can be administered alone or in combination with chemotherapy or after surgical procedures, such as a lumpectomy or mastectomy. Radiation therapy is a preferred treatment option in stage-4 breast cancer.
It uses specific drugs to kill or stop the growth of cancer cells. These drugs interfere with the process of cell division and promote cancer cell death. In breast cancer, chemotherapy is recommended before the surgery to shrink a tumour or after the surgery/ radiation therapy to kill remaining cancer cells. It is also recommended to control the spread during the advanced stage.
It is recommended to treat breast cancers that are sensitive to hormones, such as estrogen or progesterone. This therapy acts by reducing the production of hormones or blocks them from working. Thus, it helps prevent a cancer recurrence. Hormonal therapy may be given before or after the surgery to shrink a tumor and to lower the risk of recurrence.
It uses specific drugs or substances to destroy cancer by targeting specific characteristic of cancer cells. Targeted therapy is recommended in patients whose breast cancer cells overexpress certain characteristic of proteins on cancer cell surface, thereby allowing the abnormal growth pattern.
It uses certain medicines to boost a person’s immune system to find and destroy the cancer cells. Atezolizumab and pembrolizumab are among the few drugs approved for breast cancer treatment.
Even though, breast cancer being the most diagnosed cancer in women, there is no proven way to completely prevent it. A routine screening and self-examination are the key for early diagnosis and better prognosis.
- Breast self-examination
Perform self-examination every month, usually two weeks after menstrual period to check for any lumps or tender areas or any abnormal changes in the size or texture of breasts.
- Breast cancer screening
Mammography is the best tool to screen healthy women for breast cancer. It is an imaging technique that uses low doses of X-rays to detect any lumps that cannot be felt during a physical examination.
In addition to the above measures, the following options may help in reducing your risk of breast cancer:
- Practicing a healthy lifestyle and eating habits
- Limiting alcohol
- Smoking cessation
- Conceiving early
- Breastfeeding, if possible
- Avoiding birth control pills, particularly after the age of 35 years
Although there is no way to prevent breast cancers, proper diagnosis and treatment may reduce its risk. Follow-up care and positive attitude throughout the treatment will help in better outcomes.
- Breast Cancer Statistics And Resources. https://www.bcrf.org/breast-cancer-statistics-and-resources . Accessed on: 13-08-2020.
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- https://main.icmr.nic.in/sites/default/files/Health_News_8.pdf. Accessed on: 13-08-2020.
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- Breast cancer. https://www.radiologyinfo.org/en/info.cfm?pg=breast-cancer. Accessed on: 13-08-2020.
- Breast cancer. https://www.cancer.net/cancer-types/breast-cancer/introduction. Accessed on: 13-08-2020.
- Breast cancer. https://www.cancer.gov/types/breast. Accessed on: 13-08-2020.
- Breast cancer. https://www.mayoclinic.org/diseases-conditions/breast-cancer. Accessed on: 13-08-2020.
- Breast cancer. https://www.cancer.org/cancer/breast-cancer.html. Accessed on: 13-08-2020.
- Liu Y, Nguyen N, Colditz GA. Links between alcohol consumption and breast cancer: a look at the evidence. Womens Health (Lond). 2015;11(1):65-77.