Research Needed Into Rising Teen Cancers

Cancer in teenagers and young adults has risen to become the most common cause of natural death for their age, but not enough research is being done into its causes or treatment.

Cancer among 13-24 year olds is still rare, with about 1,500 new cases diagnosed each year in Britain.

But while survival rates for children and adults with the disease have improved in recent decades, they have remained unchanged for adolescents and young adults.

"We've orphaned this particular age group," Professor Archie Bleyer, of the University of Texas MD Anderson Cancer Center in Houston, told the Third International Conference on Adolescent Cancer.

"Young people and older adolescents have been left behind."

Bleyer and other cancer experts said teenagers have fallen into a medical gap. Although they develop specific types of cancer and have different medical and psychological needs, they are either treated as children or adults.

Little is known about the causes or risk factors of teenage cancers, yet few young people are involved in clinical trials to discover underlying reasons why they develop the disease or the best ways to treat it.

"There is a great need for high-quality research," said Charles Stiller, of the University of Oxford.

In one of the largest studies done into teenage and young adult cancer involving 21 years of data, Professor Jill Birch of the University of Manchester in England, said cases in Britain have risen from 15.4 to 19.8 per 100,000 between 1979 and 2000 -- an average increase of 1.2 percent per year.

Leukemia was most common in 13 and 14-year-olds, followed by lymphoma and brain tumors. But by 15 and above, lymphoma accounted for the great number of cases.

"The early age of onset and lack of opportunity for chronic exposure to environmental factors suggests that genetic susceptibility may be important," said Birch.

But she added that genetic mutations probably only account for a small number of cases.

"What is more likely is that a cancer develops as a result of exposure to a risk factor in a genetically susceptible individual," she said.

Early exposure to viruses, passive smoking and lifestyle changes, particularly increased sun exposure, may also play a part. Rates of melanoma, the most serious type of skin cancer, have almost doubled over 21 years in the 20-24 age group in Britain and it now accounts for one in 10 of all cancers.

"Worldwide, we need a new discipline in adolescent and young adult oncology," said Bleyer.

"Until we devote resources specially to this age group, there will be little progress," he added.