Understanding Breast Cancer
Breast cancer is the most common cancer a woman may face in her lifetime and the most common cancer in women worldwide. The lifetime risk of a woman having breast cancer is 1 in 8 . The risk of developing breast cancer increases with age, but Asian women are being diagnosed at a younger age compared to their Western counterparts.
The peak age of breast cancer is about 10 years younger in Asia. In a study of more than 1,200 patients found women from Asian backgrounds are more likely to develop cancer in the younger age bracket of 40-50. 
However, with early detection, increased knowledge and a better understanding of the biology of breast cancer coupled with advances made in breast cancer research and the development of improved treatments have increased survival rates for people with breast cancer tremendously.
What is breast cancer?
In a healthy body, natural systems control the creation, growth and death of cells. Cancer occurs when these systems don’t work and cells don’t die at the normal rate. So, there’s more cell growth than cell death. The excess growth can form a tumour. 
Breast cancer is a malignant tumour (a collection of cancer cells) arising from cells in the breast that divide and grow out of control. The tumour can usually be identified in an x-ray or felt as a lump. It is important to note, that not all breast lumps are cancer. Non-cancerous breast tumours are abnormal growths but do not spread outside of the breast and are not life threatening. The best way to know for sure is to seek advice from your health care provider. Though breast cancer occurs predominantly in women, it can also occur in men.
There are different types of breast cancer. It can be diagnosed at different stages and can grow at different rates. This means that the type and stage of cancer a patient has been diagnosed with determines the type of treatment they will receive.
How does breast cancer start and how does it spread?
To have a better understanding of how breast cancer starts and spreads, it is best to first have a clear understanding of the anatomy of a woman’s breast. Breasts are made up of fat and breast tissue (glandular tissue) which consists of a complex network of lobules (small round sacs that produce milk for breast-feeding) and ducts (tubes that carry the milk from the lobules to the nipples).
Image Source: https://www.cancer.org/cancer/breast-cancer/about/what-is-breast-cancer.html
Between 50-75 percent of breast cancers begin in the milk ducts (ductal cancers), about 10-15 percent begins in the lobules (lobular cancers) and a few begin in other breast tissues. 
Breast cancer can spread (metastasize) to other parts of your body through the lymph system or bloodstream. 
WHAT CAUSES BREAST CANCER?
There isn’t one absolute factor which causes breast cancer. Most cases of breast cancer happen by chance. Only around 5% of breast cancer is caused by inheriting an altered gene.  Researchers haveidentified hormonal, lifestyle and environmental factors that may increase your risk of developing breast cancer, but we have yet to discover how these factors cause the development of a cancer cell.
Factors that are associated with an increased risk of breast cancer include:
- Being female.
- Increasing age.
- A personal history of breast conditions or breast cancer.
- A family history of breast cancer.
- Radiation exposure.
- Beginning your period at a younger age (before age 12).
- Beginning menopause at an older age.
- Having dense breast tissue.
- Having your first full-term pregnancy at an older age (after age 30).
- Never having been pregnant.
- Postmenopausal hormone therapy.
- Drinking alcohol.
EARLY DETECTION & DIAGNOSIS
Sometimes, breast cancer is found when symptoms appear such as a lump in the breast, a rash, discharge from the nipple or pain in the breast area.  But many women with breast cancer may not show the common signs and symptoms. This is why every woman should have regular breast screenings.
Breast cancer screening tests include clinical breast exams and mammography, which is an x-ray of the chest to look for changes that may be signs of breast cancer. Some health care providers may also recommend a breast ultrasound or breast MRI to aid in the diagnosis.
The earlier breast cancer is detected and diagnosed, the quicker and more efficiently patients can receive the relevant treatment.