Osteosarcoma commonly occurs in the long bones of the leg or arm
The survival rate of young people with a rare form of bone cancer has not improved in 20 years, say experts.
A study has found that only 53% of those with osteosarcoma were alive five years after diagnosis - a figure that has not changed since 1981.
Figures in the British Journal of Cancer also showed the UK was lagging behind Western Europe on survival.
The Bone Cancer Research Trust said the findings highlighted the urgent need for new and better treatments.
Every year in the UK around 400 people are diagnosed with bone tumours, of which osteosarcoma is one of the most common.
They generally affect people between the age of 10 and 25 and are treated with surgery, possibly amputation, and chemotherapy.
In the study, researchers looked at survival of those under 14 years in northern England and the West Midlands between 1981 and 2002.
Over that period, survival rates for another type of bone cancer, called Ewing's Sarcoma did seem to improve slightly.
The researchers said the poor progress on survival could be due to continuing problems with delays in diagnosis and a lack of new treatments.
Study leader Dr Richard McNally said the priority should be to get UK survival rates to the same level as those seen in countries such as Germany.
He added: "This is a major indicator that future research needs to be directed towards improving survival."
Professor Ian Lewis, an expert in bone cancer at St James's Hospital in Leeds, said survival rates improved quite dramatically between the 1970s and 1980s, but then stuck.
"Survival in the UK is not as good as survival in some other countries and one reason is we haven't improved diagnostic methods."
He added that a drug called mifamurtide, which had been shown in the US to improve survival by 7-8%, was currently under consideration by the National Institute of Health and Clinical Excellence (NICE).
"If that was available that would be a big improvement on what we're doing currently," he said.
Although it would be rare for a GP to come across a patient with osteosarcoma, the pain and swelling associated with the tumour are unusual symptoms in young people and should warrant immediate referral to a specialist, he said.
"It is not uncommon for diagnosis to take weeks or even months."
Michael Francis, chairman of the Bone Cancer Research Trust, said: "Too many of the children and young people with bone cancer still die from their disease.
"We need to make bone cancer a priority and we urgently need more research to identify effective new treatments.
"The government needs to play its part and streamline the process for introducing new treatments into the UK."
Professor Peter Johnson, Cancer Research UK's chief clinician, said: "Overall, seven out of ten children with cancer are now successfully treated, compared with less than three out of ten in the 1960s.
"We know that the best way of improving survival for children with cancer is through research and by supporting clinical trials."