Never being married when diagnosed – rather than being divorced or widowed – doubled the death rate in men from 18 to 35 per cent and in women more modestly from 17 to 22 per cent.

Previous studies have shown married people generally have better health and live longer than single people, as they tend not to smoke and drink as heavily, and have better mental health. The researchers at the University of Oslo say this is likely to be a factor in cancer death rates.

They also suggested that married people are probably diagnosed earlier as they tend to visit the doctor more and may comply better with treatment as they have a spouse to support them.