Teenage cancer patients are missing out on life-saving treatments because few clinical trials are open to young people. Arbitrary age restrictions means young adults are often too young or too old to participate in drug trials, leaving doctors to later ‘guess’ what doses work best for this age group.

Survival rates for teenagers and young adults have improved by only 11 per cent in the last two decades - less than half the rate for children with cancer. Cancers cells and drugs work differently in youngsters because of growth spurts, puberty and hormonal changes.

Even when trials are open to young people, only a third are offered the opportunity to participate, according to Dr Jeremy Whelan, chair of the National Cancer Research Institute Teenage and Young Adult clinical studies group.

Data to be presented by Dr Whelan at the NCRI conference in Liverpool this Tuesday shows young people, aged between 13 and 24, also fare substantially worse than children and older adults with the same cancer. Five year survival rates for young breast cancer patients are around 15 per cent lower than for older women. The situation is even worse for some childhood cancers. Nine out of 10 children will survive acute lymphoblastic leukaemia - nearly three times the survival rate for adults aged 21 to 24.

Young cancer patients also face a hospital post-code lottery as less than half treated in a specialist ward, warns the Teenage Cancer Trust (TCT). The rest end up in either child or adult wards without the right expertise, no peer support, and little chance of hearing about clinical trials, said Simon Davies, TCT chief executive.

This comes as new research by the National Cancer Research Network shows the number of UK cancer patients participating in clinical trials has quadrupled over the last decade. One in six cancer patients now enter clinical trails - more than any other European country or the US. The increase has been much slower for teenagers and decreased for those aged 20 to 24.

Dr Lorna Fern, R&D coordinator of the Teenage and Young Adult clinical studies group, said: “Teenagers and young adults are the lost tribe, caught in no man’s land. The historical boundaries between paediatric and adult medicine are arbitrary and detrimental for this age group. Significant improvements in outcomes for young people with cancer will remain elusive without a coalition of forces between funders, policy makers, biologists, clinicians and patients.”

Cancer is generally an aging disease: around 2,000 young people are diagnosed with cancer in the UK every year compared with 300,000 older adults. They are most prone to rare cancers of the brain, bone, testes, bone marrow and white blood cells. Drug companies are “reluctant” to invest money into these rarer cancers so progress has been slow, say experts. Doctors and researchers underestimate the side effects many young survivors must endure for years.

The well researched common cancers – breast, colorectal and prostate – have seen the most impressive improvements over the last 20 years but are very rare in young people. And because GPs encounter few, if any teen cases, during their careers, late diagnosis is common.

A new drug may increase a patient’s chance of survival but can also prolong treatment and cause worse side-effects. Dealing with the prospect of infertility, scars and hair loss is particularly tough at this age, so information about the benefits of clinical trials needs to be much clearer, argues Dr Fern.

Hannah Millington, 29, from Birmingham was diagnosed with osteosarcoma - a bone cancer – when she was 25.

During a 10 minute conversation with a junior doctor she had to choose between a drug trial, which might save her life but could cause hearing and sight loss, and saving her fertility. The information was neither complete nor accurate so she missed out on the trial.

Things have started to improve since the National Institute of Clinical Excellence issued guidance in 2005. Researchers are slowly being persuaded to remove arbitrary age barriers in clinical trials but the benefit will not be seen for several years.

There are 17 TCT wards in the UK. The charity pays for the ward – individual PCs, juke boxes and pool tables – specialist nurses and a youth worker; the NHS pays for the rest.

Mr Davies said: “We don’t expect primary school teachers to teach secondary school kids, but we’ll allow a six foot 14 year old to be treated by a paediatric nurse in a children’s ward where he can’t even fit into the bed. You cannot underestimate the importance of young people being together, there is nothing more important at that age. It isn’t rocket science.”

James Ashton, 29, from Sheffield, an aerospace engineering student, was first diagnosed with testicular cancer at 21.

“Life was a laugh until I turned 21 then my dad died, I got cancer and it all got serious. I found an egg sized lump in my ex-left ball which meant it was removed along with my sex organs on that side, followed my radiotherapy. There were no clinical trials for testicular cancer but I would have jumped at the chance to try something which could have improved my quality of life, but no-one ever talked to me about the long-term effects. There is an air of 'you should feel grateful about surviving, not winging about feeling awful', but I've been left with low testosterone which means I have no energy; weight gain and impaired sexual function. I was admitted to a Teenage Cancer Trust ward for chemo after I found another tumour, a secondary, in my groin. This was much better, you had your own PC, specialist nurses, other young people to talk to, and they really paid attention to the bigger picture. For someone my age, the rest of my life is as important as surviving, so even though people think we're too difficult to pin down for trials, we want the opportunity.”