Cancer doctors are worried Australian patients will miss out on access to what has been called the biggest breakthrough in pancreatic cancer in two decades.

Abraxane is one of the only treatments shown to help patients with advanced pancreatic cancer.

But the company distributing the drug has written to all Australian oncologists saying it will no longer be able to supply the medication.

It says the Federal Government has asked them to supply the drug at well below cost price, making it unviable.

The company says no new patients can join the scheme which gives the drug to patients on compassionate grounds.

Around six people a day apply to get the drug, which can extend a patient's life by up to three years.

Professor John Zalcberg from Melbourne's Peter MacCallum Cancer Institute says it is bad news for patients.

"If that turns out to be the case, that will be very disappointing because this is a disease, when it's advanced, that has a very bad prognosis," he said.

He says trials of Abraxane show it can reduce tumour size and stop the disease's progression.

Professor Zalcberg chairs the Australian Gastrointestinal Trials Association, which has received research funding from the distributor of Abraxane.

The drug is fully subsidised in the United States and the United Kingdom.

One patient to benefit from Abraxane is Sydney Terrence.

He was diagnosed with pancreatic cancer just before his 71st birthday and says the drug is his last hope.

"I always try to keep a positive front on it. I try to think that I am beating this. I suppose I am hoping for the most but I am prepared to accept the worst," he said.

"Without this, I would have had another couple of months of life left. This is possibly offering me one to two years."

In the letter to oncologists, the company Specialised Therapeutics Australia says: "It is with great regret I must advise you that it is highly likely that the Abraxane Access program will close."

"We understand only too well that this will have a tremendous impact on the ability of many patients and their families to afford (the drug)," it said.

The company says it has supplied Abraxane to more than 1,000 patients with advanced pancreatic cancer, through the special access scheme.

A statement from the Federal Health Department says Abraxane for the treatment of pancreatic cancer was considered by the Pharmaceutical Benefits Advisory Committee at its recent meeting in March 2014.

The committee's decision will be publicly available on April 24.

The Federal Government has the final say on whether the drug will be subsidised.