Over half of cancer patients have been identified as suffering from insomnia during treatment, with these sleep problems persisting for months after any procedures, a new study has found. Researchers led by Josee Savard of the Laval University Cancer Research Centre in Quebec told Reuters of their study of 1,000 patients having surgery for cancer. All of those involved were asked if they had trouble sleeping. Patients between 23 and 79 years old mostly had early-stage cancer and 59 per cent of patients reported to suffer from insomnia. Half of these were severe enough to qualify for insomnia syndrome; this meant the overall was three times higher than the population at large. Dr Savard told the Journal of Clinical Oncology: "Insomnia is a frequent and enduring problem in patients with cancer, particularly at the syndrome level. Early intervention strategies, such as cognitive-behavioral therapy, could prevent the problem from becoming more severe and chronic."