Access to combination HIV therapy has significantly improved

Aids-related deaths are at the lowest level since their 2005 peak, down 21%, figures from UNAids suggest.

Globally, the number of new HIV infections in 2010 was 21% down on that peak, seen in 1997, according to UNAids 2011 report.

The organisation says both falls have been fuelled by a major expansion in access to treatment.

Its executive director, Michel Sidibe, said: "We are on the verge of a significant breakthrough."

He added: "Even in a very difficult financial crisis, countries are delivering results in the Aids response.

"We have seen a massive scale up in access to HIV treatment which has had a dramatic effect on the lives of people everywhere."

This latest analysis says the number of people living with HIV has reached a record 34 million.

Sub-Saharan Africa has seen the most dramatic improvement, with a 20% rise in people undergoing treatment between 2009 and 2010.

About half of those eligible for treatment are now receiving it.

UNAids estimates 700,000 deaths were averted last year because of better access to treatment.

That has also helped cut new HIV infections, as people undergoing care are less likely to infect others.

In 2010 there were an estimated 2.7m new HIV infections, down from 3.2m in 1997, and 1.8m people died from Aids-related illnesses, down from 2.2m in 2005.

The figures continue the downward trend reported in previous UNAids reports.

The UN agency said: "The number of new HIV infections is 30-50% lower now than it would have been in the absence of universal access to treatment for eligible people living with HIV."

Some countries have seen particularly striking improvements.

In Namibia, treatment access has reached 90% and condom use rose to 75%, resulting in a 60% drop in new infections by 2010.

UNAids says the full preventive impact of treatment is likely to be seen in the next five years, as more countries improve treatment.

Its report added that even if the Aids epidemic was not over: "The end may be in sight if countries invest smartly."

The charity Medecins Sans Frontieres urged governments to keep up their funding.

MSF's Tido von Schoen-Angerer, said: "Never, in more than a decade of treating people living with HIV/Aids, have we been at such a promising moment to really turn this epidemic around.

"Governments in some of the hardest hit countries want to act on the science, seize this moment and reverse the Aids epidemic. But this means nothing if there's no money to make it happen."

The International HIV/Aids Alliance said: "We welcome the ongoing commitment of UNAids to changing behaviours, changing social norms and changing laws, alongside efforts to improve access to HIV treatment.

"For bigger and better impact though, we must not be complacent. There is still much more to do."

The drug-maker says it will undertake further study to establish which patients will benefit from the drug

US drug regulators have rescinded approval of a breast cancer drug, saying it is not effective enough to justify the risks of taking it.

The drug, Avastin, was approved for US use in 2008, but UK officials have also rejected claims that it prolongs life.

Further research showed it did not help patients live longer or improve quality of life, Food and Drug Administration commissioner Margaret Hamburg said.

Avastin will still be used to treat other kinds of cancer.

The drug is used to treat breast cancer that has spread to other parts of the body. It works by starving cancer cells of a blood supply.

However, its side-effects include severe high blood pressure, massive bleeding, heart attack or heart failure and tears in the stomach and intestines, FDA studies have found.

FDA approval of the drug had initially been given under a special programme that allows patients to start using promising treatments while the manufacturer finishes the studies to prove the medicine works as well as expected.

The decision to withdraw the approval - which can happen if results of the research do not match predictions - was not easy, the FDA said.

"With so much at stake, patients and their doctors count on the FDA to ensure the drugs they use have been shown to be safe and effective for their intended use. Sometimes, the results of rigorous testing can be disappointing," Ms Hamburg told the Associated Press news agency.

US health insurance companies could remove the drug, which can cost as much as $100,000 (£63,342) per year, from their coverage - although doctors would still be permitted to administer the drug.

But the government-backed Medicaid programme has said it has no immediate plans to change its policy of paying for it.

Some advocates of the drug disagree with the watchdog's decision.

"The bottom line is that they are throwing out the baby with the bathwater. There absolutely may be subsets of carefully chosen breast cancer patients who benefit from Avastin," said Dr Elisa Port, co-director of the Dubin Breast Center of Mount Sinai Hospital in New York.

Roche, the Swiss manufacturer of the drug, has said it will undertake further study of the treatment, especially with the chemotherapy drug paclitaxel, to try to identify which patients might be best suited to benefit from use of the drug.

The company says it expects the medicine will generate $7.6bn (£4.8m) of revenue annually, despite the FDA decision.

The drug was approved on the basis of a study that showed Avastin was able to stall the growth of breast cancer by five-and-a-half months, when used together with a standard chemotherapy treatment.

But subsequent studies revised the period of delay to between one and three months, and there was no evidence to show that the drug extended patients' lives.

The US decision comes after Avastin fell foul of health authorities in the UK and in Europe.

In February 2011, the UK's National Institute for Health and Clinical Excellence (NICE), the NHS drugs advisory body, said Avastin should not be used to treat secondary breast cancers.

NICE, which issues guidance for NHS in England and Wales, said there was insufficient evidence that the drug prolonged life.

This guidance followed a recommendation by the European Medicines Agency (EMA) that doctors only prescribe the drug in combination with the taxane drug, paclitaxel.