Breast cancer is one of the leading causes of mortality among women in the world today. The actual cause of breast cancer is not fully known and is probably due to a multitude of factors. Breast cancer today is the most common cancer among women throughout the world. The incidence is much higher for women over 65 years of age when compared to those in the 45 to 64 age group. However, the incidence of breast cancer is increasing in younger women and many cases of this disease are being reported in women in their twenties and thirties. The incidence of breast cancer among women across all ages is also continuing to rise.
  

 
The actual cause of breast cancer is not known and is probably due to a variety of factors. A large proportion of women diagnosed with breast cancer do not exhibit any known risk factors, which include familial history, early menarche or late menopause, nulliparity or first child born after the age of 30, exposure to ionising radiation, personal history of cancer or atypical hyperplasia, and excessive tobacco consumption. Other factors like hormonal imbalances, genetic predisposition or viruses may also play a part.
 

The most common sign of breast cancer is a lump in the breast. About 50% of the lumps are found in the upper outer quadrant. Nipple discharge may be present. Pain, tenderness, changes in breast shape, dimpling, puckering (orange-peel appearance of the skin), and nipple retraction may occur as the disease progresses. In advanced stages ulceration may develop on the skin and signs of secondary metastasis to other organs like the lungs, liver and lymph nodes may be present.
 

 
The best investigation is regular self-examination of the breasts. A mass detected by breast self-examination, physical examination, or mammogram needs further follow-up. Ductal carcinomas account for 75% of all breast cancer, lobular and nipple carcinomas account for most of the remaining 25%. Definitive diagnosis is made by incisional, excisional, or needle biopsy of the mass. Mammography is a very effective method of diagnosing cancers of the breast in their early stages even before they are palpable. Therefore, routine mammograms are now recommended for all women deemed to be in the high-risk category for developing breast cancer.
 

There are three main methods of treatment used in breast cancer.
 

 
The treatment consists of resection of the lump with removal of a varying amount of surrounding healthy tissue, ranging from a margin of breast tissue to the entire breast, axillary lymph nodes, mammary lymphatic chain, and pectoral muscles. Breast reconstruction can be done later for cosmetic purposes.
 

 
Counselling the patients is important especially as they are often distressed by the altered body image. Patients must also be taught to look for early signs of the disease either in the same breast (if not fully removed) or in the opposite breast.
  
The prognosis worsens as the number of groups of involved lymph nodes increases. Pleural effusion (accumulation of fluid in the pleural spaces around the lungs), ascites (fluid in the peritoneal cavity in the abdomen), pathologic fractures, and spinal compression can occur with advanced disease and these are some of the symptoms of advanced disease that have a relatively poor prognosis.
 

 
The best way to prevent breast cancer is by early detection and treatment, before secondary spread occurs. This can be done by regular breast self-examination and mammography. All suspicious lumps should be investigated by biopsy to rule out malignancy. All women with a family history and in the high-risk group should undergo periodic mammogram examinations. Self-Examination must be taught to every woman who has attained menarche irrespective of age.