Cancer services in England are disjointed and need to be reformed, according to a parliamentary report.
The report said many primary care trusts were "struggling"
The All-Party Parliamentary Group on Cancer said the new funding system was "exacerbating" the postcode lottery.
It claimed GPs were not referring those needing urgent treatment quickly enough and said primary care trusts (PCTs) should not be responsible for funding.
It comes as the government announces a national screening programme for bowel cancer, aimed at cutting deaths by 15%.
Health Secretary John Reid said the government would be spending £37.5m on the programme, which will start in April 2006.
Answering the cross-party report's criticism of cancer funding, Mr Reid said there had been a 12% reduction in the number of cancer deaths since 1997.
"We will listen, but I am yet to be persuaded that it is better than what we are doing," he said.
"The proof of the pudding is in the eating and the results speak for themselves."
The report called for the control of cancer budgets to be handed to the country's 34 cancer networks.
The networks are non-statutory alliances between primary care trusts, hospitals, councils and the voluntary sector, which support and plan services on a regional level.
It said many of the country's 302 PCTs, which commission health services and have responsibility for spending three quarters of the NHS budget, were "struggling".
As a result, it said, there were "worrying implications for the provision of all NHS services but particularly for national priority areas like cancer".
The report also recommended GPs go on cancer education programmes to help them recognise which patients need urgent treatment.
Report's main recommendations
Strip PCTs of funding powers
Hand budgets to cancer network
Send GPs on cancer education courses
Set up cancer treatment database
Witnesses told the inquiry, which took evidence from the Department of Health, PCTs and patient groups, that PCTs lacked experience - and in many cases expertise - in commissioning cancer services.
Ian Gibson, chair of the All Party Parliamentary Group, said: "The inquiry has exposed a serious problem.
"PCTs are struggling to cope and lack experience in commissioning cancer services.
"The budget for cancer services must therefore go directly to cancer networks to allow them to plan for sustained improvements in cancer care."
Joanne Rule, chief executive of CancerBACUP, a cancer information charity which co-authored the report, said cancer services needed specialist commissioning.
"If not, access to cancer drugs, equipment and services will continue to vary widely from one part of the country to another," she said.
"Cancer patients deserve more."
The report also suggested data be collected at both national and local levels on the prescribing of cancer treatments recommended by the National Institute for Clinical Excellence.
Mayur Lakhani, chair-elect of the Royal College of GPs, denied family doctors were at fault.
"GPs don't have a problem referring patients for cancer screening - the issue is the availability of scans and tests."
Professor John Toy, medical director at Cancer Research UK, said cancer treatment was improving but that it was unacceptable that quality of care was still being "determined by a person's address".
And Dr Michael Dixon, chairman of the NHS Alliance, which represents PCTs, said as PCTs were only a few years old they were not always as "sharp on commissioning" as they could be.
But he added the situation was improving.