Nearly 3,000 cancer patients were quizzed
A significant number of cancer patients regularly believe they would be "better off dead", a survey shows.
Patients were most likely to have these thoughts if they had substantial pain and serious emotional distress, the Edinburgh University researchers said.
They said it showed there needed to be more services to combat depression.
The poll of 2,900 UK patients found 8% wanted to die or badly hurt themselves in the previous fortnight - three times more than the general population.
The patients, who had a range of cancers, answered a questionnaire about their physical and emotional symptoms.
Among the questions, patients were asked: "Over the last two weeks how often have you been bothered by the following problem: thoughts that you would be better off dead, or of hurting yourself in some way?"
Patients could answer: "not at all," "several days," "more than half the days" or "nearly every day."
Some 8% had had thoughts of being better off dead or of hurting themselves at least several times during the period.
This compares with a figure of just 2.6% in a similar survey of the general population.
Lead author Jane Walker said: "It is worrying that, despite improvements in cancer care, a substantial number of patients feel they would be better off dead.
"We know that depression is common in patients who have cancer but it is often missed.
"Pain is also a big problem. Treating patients' symptoms as well as their disease might improve, and even save, their lives."
Dr Lesley Walker, Cancer Research UK's director of cancer information, said: "It is normal to experience distress after a cancer diagnosis.
"But for some patients emotional distress or depression becomes a problem in itself and may lead to suicidal thoughts.
"Cancer specialists and GPs can provide treatment, with the help of psychiatrists if necessary."