Recent advances in treatment mean it is possible to start talking about curing some types of cancer, the world's biggest maker of cancer drugs said on Thursday.

Swiss-based Roche argued the use of modern medicines, such as breast cancer drug Herceptin, at an early stage of disease was transforming the outlook for patients.

"There is a quantum leap here," William Burns, Roche's head of pharmaceuticals, told analysts in London, after the company reported a surge in first-half profits on the back of strong cancer drug sales.

"The word 'cure' can start to come into the discussions on non-Hodgkin's lymphoma, for some people, and for breast cancer for ladies with early-stage HER2-positive (disease)."

Roche's drug MabThera, or Rituxan, is used to treat non-Hodgkin's lymphoma, a type of cancer that affects the white blood cells, while Herceptin has been shown to cut cancer recurrence in women with aggressive HER2 breast cancer.

Avastin, which works by starving tumors of blood supply, is another medicine from Roche's partnership with majority-owned Genentech that is revolutionizing treatment.

All are examples of so-called "targeted therapies" that extend lives with far fewer toxic side effects than standard chemotherapy for certain groups of patients.

However, the high price of targeted therapies -- running to tens of thousands of dollars a year -- has been criticized by patient groups and payers, prompting talk of a backlash, similar to the controversy over AIDS drug prices in the 1990s.

But Burns said cancer medicines still accounted for only a tiny fraction of spending, with oncology therapies making up just 1/2 percent of healthcare expenditure in Europe, according to recent study by Sweden's Karolinksa Institute.

Newer treatments were highly cost-effective, he said, adding that governments should look to looming savings on medicines about to go off patent to help pay for them.

"There are billions of dollars of pharmaceuticals that are going off patent. That can provide oxygen to the system before we need to print a new euro or pound or dollar," he said.

The recent advances in fighting cancer have made oncology the fastest-growing section of the pharmaceuticals market, tempting many more companies into the field.

Rival include industry giants like Pfizer and GlaxoSmithKline, which has a similar drug to Herceptin called Tykerb that is now awaiting regulatory approval. But Burns said it would be several years before Glaxo had sufficient clinical trial data to make Tykerb a significant competitor.

Roche's sales of cancer medicines totaled 10.2 billion Swiss francs ($8.18 billion) last year and sales climbed 48 percent in the first half of 2006.