Breast cancer is the second leading cause of cancer deaths among women. The development of breast cancer is a multi-step process involving multiple cell types, and its prevention remains challenging in the world. 1 in every 9 women is at risk of breast cancer in Pakistan. Early diagnosis of breast cancer is one of the best approaches to prevent this disease. Even though every woman of reproductive age is prone to breast cancer, following are the risk factors that increase one’s risk for this disease.

1. Aging
Aging is one of the most important risk factors of breast cancer.
Chances of breast cancer increase with increasing age. This is why there is great emphasis on screening through yearly mammogram of women forty years old or older. Women over 20 should also get regular clinical examination of breasts done.

2. Family History
Nearly a quarter of all breast cancers are related to family history. Women, whose mother or sister has a breast cancer, are prone to this disease. The inherited susceptibility to breast cancer is partially attributed to the mutations of breast cancer related genes such as BRCA1 and BRCA2.

3. Reproductive Factors
There are certain reproductive factors that put one at a greater risk for breast cancer.
• Early Menarche (start of menstrual cycle)
• Late menopause (cessation of menstrual cycle)
• Late age at first pregnancy
• Low parity
Each 1-year delay in menopause increases the risk of breast cancer by 3%. Each 1-year delay in menarche or each additional birth decreases the risk of breast cancer by 5% or 10%, respectively.

4. Estrogen
Both endogenous and exogenous estrogens are associated with the risk of breast cancer. The endogenous estrogen is usually produced by the ovary in premenopausal women. The main sources of exogenous estrogen are the oral contraceptives and the hormone replacement therapy (HRT). Long Term use of oral contraceptive pills and hormone replacement therapy increases the risk of breast cancer.

5. Life Style
Sedentary life style, lack of exercise and excessive fat intake especially saturated fat is linked with higher mortality and poor prognosis in breast cancer patients.

Unfortunately, even if all the potentially modifiable risk factors could be controlled, this would only reduce the risk of developing breast cancer by at most 30%. Hence, the importance of screening and regular self-examination of breasts, despite the absence of risk factors, should not be ignored.
References: 1. Sun Y, Zhao Z, Yang Z, Xu F, Lu H, Zhu Z et al. Risk Factors and Preventions of Breast Cancer. International Journal of Biological Sciences. 2017; 13(11):1387-1397.