Cancer (medical term: malignant neoplasm) is a class of diseases in which a group of cells display uncontrolled growth (division beyond the normal limits), invasion (intrusion on and destruction of adjacent tissues), and sometimes metastasis (spread to other locations in the body via lymph or blood). These three malignant properties of cancers differentiate them from benign tumors, which are self-limited, do not invade or metastasize. Most cancers form a tumor but some, like leukemia, do not. The branch of medicine concerned with the study, diagnosis, treatment, and prevention of cancer is oncology.

http://en.wikipedia.org/wiki/Cancer

Renowned cancer specialist Dr. Kiran Kothari from Ahmedabad speaking on breast cancer:

As women marry late, their child-bearing age has extended beyond 30 years. The women in India today are at a much higher risk of breast cancer than ever before. They are emulating the West and are today more career-oriented and like the trend in the West are marrying late, delaying the child-bearing age up to 30 years or beyond, making them vulnerable to the disease.

It is going to take the shape of an epidemic in 10-15 years as a number of women in the country will suffer from breast cancer, making it one of the most dangerous forms of cancer. While the rate of incidence under 40 years of age in the West stands at 2 to 4 per cent, the country has 10-12 per cent rate of incidence under 40 years now.

Article courtesy of
http://www.indianexpress.com/news/late-child-bearing-leads-to-breast-cancer-e/403995/