Breast cancer

DESCRIPTION

Definition
 
Breast cancer is cancer that develops due to uncontrolled growth of breast tissue cells.
The breast tissue contains milk producing glands called lobules and thin tubes called ducts. Cancer can begin in either of these. Depending on where the cancer begins, breast cancer is of two types:
1. Ductal carcinoma that develops in the cells of the lining of milk duct.
2. Lobular carcinoma that develops in the lobules
Breast cancer usually affects women. However, it can also occur in men and children, though the incidence is rare. In India, breast cancer has become the most common cancer among women.
 
Causes and Risk Factors
 
Breast cancer may be caused by genetic, environmental, or lifestyle factors. The factors that increase the risk of breast cancer include:
1. Age. However, in Indian population breast cancer seems to be more common in younger age group, below 50 years.
2. Family history
3. Presence of certain harmful mutation of genes [breast cancer genes 1 and 2 (BRCA1 and BRCA2)]. It carries a risk of 40% to 85%.
4. Early start of menstruation (before 12 years) and delayed menopause (after 55 years).
5. Never being pregnant or late first child
6. Smoking and alcohol intake of more than two glasses a day
7. Obesity after menopause
8. Hormone therapy after menopause (estrogen with progestin)
9. Exposure to radiation
 
Signs and Symptoms
 
Signs and symptoms include:
1. Presence of a lump in the breasts that feels different from the rest of the breast tissue
2. Changes in the size, shape, or appearance of the breast
3. Inverted, painful, or enlarged nipple
4. Discharge from the nipple
5. Skin dimpling or appearance of folds on breast skin
6. Pain around breast
Swollen lymph nodes (in underarms and around collarbone) may indicate that the cancer has spread.
 
Investigations
 
1. Physical examination of the breast
2. Mammography (X-ray) of the breast to identify the breast lump.
3. FNAC (fine needle aspiration cytology): A fine gauge needle is used to remove fluid from the breast tissue for microscopic evaluation.
4. Excision biopsy: A mass of tissue is removed for examination. This is used to determine the types of cells involved in the breast cancer.
5. CT scan to check whether breast cancer has spread to other regions.
6. Breast magnetic resonance imaging (MRI): Picture of interior of breast is created by MRI to evaluate and identify breast lump.
 
Treatment
 
Treatment for breast cancer involves one or more of the following:
1. Medications such as tamoxifen or raloxifene
2. Radiation to kill cancer cells
3. Chemotherapy
4. Hormone therapy
5. Mastectomy (removal of breast)
 
Complications and When Should You See a Doctor
 
See a doctor if you feel a lump in your breast or have a discharge from the nipple. Opt for regular mammography (once a year) if you have a family history of breast cancer.
 
Prognosis and Prevention
 
The prognosis of breast cancer depends on:
1. Stage of cancer (lymph node status and tumor size)
2. Expression of certain proteins [estrogen receptor and progesterone receptor, human epidermal growth factor receptor 2 (ER and PR, HER2)]
3. If the woman is still menstruating or has had menopause
Regular examination and screening through mammography can help in early detection of breast cancer.
Regular exercise and maintaining a healthy weight, early pregnancy, breastfeeding, and use of estrogen after hysterectomy may reduce breast cancer risk. Removal of breast tissue and/or ovaries for high-risk patients may be recommended.
 
References
 
Rangarajan B, Shet T, Wadasadawala T, Nair NS, Sairam R M, Hingmire SS, Bajpai J. Breast cancer: An overview of published Indian data. South Asian J Cancer 2016;5:86-92 Available from: http://journal.sajc.org/text.asp?2016/5/3/86/187561
NE Davidson. Breast Cancer and Benign Breast Disorders. In: Goldman L, Schafer AI eds. Goldman-Cecil Medicine. 25th ed. Elsevier Saunders. 2016:chap 198.
National Cancer Institute. Breast cancer treatment – health professional version. Updated March 2017. https://www.cancer.gov/types/breast/hp/breast-treatment-pdq Accessed may 2017.
 

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