Six years ago my sister developed breast cancer. After the lump was removed she had radiotherapy and chemotherapy. Last year she was given the all clear. Two months ago she developed a bad cough. She has now been told that she has both lung cancer and liver cancer. Why has she been so unlucky to develop new cancers so soon after she was given the all clear?

Dr Fred Kavalier answers your health question:

When someone who has had cancer is given the "all clear", unfortunately it is only a provisional all clear. A small percentage of patients will still get a recurrence of their original cancer, even many years later. Although your sister now seems to have developed cancer in two new places, she almost certainly still has breast cancer which has now spread to the liver and the lungs. The cancer she originally got was a "primary" cancer. She now has "secondary" cancer. This means that the cancer cells in her liver and her lungs are actually breast cancer cells that have moved around the body and started to grow again. Cancerbackup's website has a good explanation of the difference between primary and secondary cancer:

Please mail your questions for Dr Fred to He regrets that he is unable to respond personally to questions.