Up to a third of British cancer patients are not given the high doses of chemotherapy necessary to fight the disease because of a lack of NHS funding, specialists said yesterday.

Patients in Britain fare worse than those in most other European countries and America, according to doctors from Addenbrooke's Hospital in Cambridge and St George's Hospital in London.

The researchers studied drug treatment at 23 cancer units throughout Britain, including leading breast cancer units at Guy's and St Thomas' Hospital, King's College Hospital and the Royal Marsden, and eight lymphoma units.

They found that chemotherapy given to large numbers of patients was below acceptable levels. In Britain, one in three breast cancer patients is given less than 85 per cent of the chemotherapy he or she is supposed to receive.

In Europe, the number receiving less than the correct dose of chemotherapy is much lower, at between eight and 17 per cent, and in the United States the figure is 18 per cent.

The main reason is that there are genuine risks associated with the use of strong anti-cancer treatments such as chemotherapy, which can lead to potentially dangerous side-effects for up to a third of cancer patients.

However, inexpensive drugs known as support drugs that could be used to combat some side-effects are only offered to a small number of patients in Britain, less than 6 per cent, because of a lack of funding.

About 20 per cent of patients are given support drugs in the rest of Europe and America. The use of support drugs allows chemotherapy to be given at the proper dosage and ensures patients have a much higher chance of survival.

Overall, the chances of surviving cancer five years after being diagnosed are 45 per cent higher in the rest of Europe than in Britain.

Dr Rob Thomas, a cancer specialist at Addenbrooke's, said there was good evidence that giving patients high doses of chemotherapy over a planned period increased their chances of survival.

"If you believe chemotherapy improves survival for cancer patients, you should believe that giving the right dose is crucial to its success," he said.

Chemotherapy is risky, though, because it can destroy the healthy white blood cells essential to ward off infection, which leads to a condition known as neutropenia. Patients with this condition often have to be admitted to hospital and one in ten dies of septicaemia.

Doctors frequently cut down on or delay chemotherapy to give the patients' blood cells a chance to recover. They were unable to use support drugs, such as Neupogen, more frequently because of a lack of funding – which made Britain a "poor relation" in the field of cancer treatment, Dr Thomas said.

Neupogen is made by a biopharmaceutical company, Am-gen, which supported the research. It says support drugs, also known as growth factors, work partly by increasing the number of white blood cells.

"This drug is vastly under-used in the UK and current lack of funding continues to severely restrict prescription of supportive care drugs," Dr Thomas said.

Cancer specialists say treatment with a support drug costs £50 a day, or about £1,000 for a course of treatment, which they claim is much less than the additional chemotherapy and hospital treatment necessary if support drugs are not used.