The value of David Cameron’s pledge to fund pioneering treatments for cancer – a showpiece of the Conservatives’ general election campaign – has come under fire from oncologists, HSJ has discovered.

A London cancer network report has questioned the affordability of the cancer drugs fund as demand increases and new treatments come to the market.

During the election, Mr Cameron heralded the fund as a sign of the Conservatives’ commitment to the NHS. Health secretary Andrew Lansley later announced that the government would resource a £200m annual fund to pay for cancer drugs which had been recommended by a patient’s oncologist but not approved by the National Institute for Health and Clinical Excellence.

A report to NHS London from South East London cancer network head Alastair Whitington said “financial factors” could mean the fund was worth only half of what was originally indicated.

The document, obtained under the Freedom of Information Act, said there were concerns the funding “will not be sufficient over the three years the fund will operate”. Applications to the fund had doubled since it started, the report said.

His report said that unless the fund kept pace with inflation, which has risen faster in drugs than the rest of the economy, its value could decrease by £46m. VAT on the drugs also accounts for 20 per cent of the fund, the document added. Further costs came from paying for tests to identify patients eligible for treatment, which the report said cost between £150 and £300 each.

It also warned “a new drug for a common cancer could utilise up to half the fund, e.g. another trastuzumab (Herceptin)”. It said two new skin cancer drugs had been “widely reported as offering survival benefits”, as had a new prostate cancer drug.

A DH spokesman said: “It is expected that each strategic health authority’s cancer drugs fund will put in place a plan to fund cancer treatments using their appropriate weighted share of the £200m cancer drugs fund, taking account of inflation and VAT.”