Nearly a quarter of cancer diagnoses in England are made when patients arrive at hospital in an emergency, a study has found.
Research by the National Cancer Intelligence Network (NCIN) found that 23 per cent of cancer cases were detected only as patients underwent emergency treatment.
The figures were even starker for sufferers of acute leukaemia and brain cancer, where well over half of cases were discovered at a critical stage.
Pensioners and those under 25 were most likely to be diagnosed with cancer during emergency procedures, while poor people were more likely to suffer from late detection than the rich.
The study found that people whose cancer was detected at an emergency stage were significantly more likely to be die within a year than those whose illness was discovered earlier.
Harpal Kumar, the chief executive of Cancer Research UK, said: "The figure for diagnoses via emergency presentations is way too high.
"This statistic helps explain why we have lower survival rates than we would hope to have, lower than the best countries in Europe."
He told the Daily Telegraph today: "We need screening programmes to be rolled out as early as possible and GPs given rapid access to the tests that will enable patients to be moved quickly through the system."
Mr Kumar said better education was needed to help people recognise the symptoms of different types of cancer.
The report was compiled by looking at all patients diagnosed with cancer in England in 2007 and examining at what stage their disease was diagnosed.
The NCIN found a disparity between different cancer types with only 3 per cent of skin cancer going undetected until an emergency stage, compared with 58% of brain cancer.
Breast cancer was the most common cancer type, representing 13 per cent of the 225,965 diagnoses made that year.
Sara Hiom, director of health information, at Cancer Research UK said the number of patients whose cancer was only being discovered at an emergency stage was "alarmingly high".
She said: "We hope the Government will seriously consider the best way to tackle this problem in their revised cancer strategy, which is due in the coming months."
A spokesman for the Department of Health said: "We are committed to improving cancer outcomes. Earlier diagnosis is crucial to match the best survival rates in Europe."