New York, Sept. 13 (Reuters): Cigarette smoke can transform normal breast cells into cancerous cells by blocking their normal ability to repair themselves.

Over time this could lead to the development of breast cancer, scientists from the University of Florida in Gainesville report. Smoking cigarettes substantially increases a person’s risk of developing heart disease.

For their research, the Gainesville team used cigarette smoke condensate or tar that contains all of the chemicals present in cigarette smoke, 81 of which have been classified as cancer-causing.

“The use of cigarette smoke condensate...mimics the human smoking situation more closely,” Dr Satya Narayan said. Narayan found that after treatment with cigarette smoke condensate normal human breast epithelial cells in culture acquire mutations characteristic of malignancy.