Risk of lung cancer from radiotherapy doubles for breast cancer patients who smoke

Cancer Research UK recently recognised smoking as a cause of breast cancer for the first time. Photograph: David Sillitoe/The Guardian

Breast cancer patients who continue to smoke after having radiotherapy are at much higher risk of their treatment causing them lung cancer in the future, research has found.

Two in three of those diagnosed with early breast cancer in the UK are given radiotherapy. It is a long-established and highly effective treatment but does also have potential side-effects.