AFP/ Paris

An investment of $97-184 billion (87-165 billion euros) could make life-saving radiotherapy accessible to most people who need it by 2035 and save millions of lives, research showed Saturday.

Achieving full access to radiotherapy in low- and middle-income countries would save an estimated 27 million "life years" -- extra years that cancer patients would have lost without treatment.

And it would yield economic benefits of $278-365 billion, through healthcare savings and higher productivity, said a major study published in The Lancet Oncology, and presented at the 2015 European Cancer Congress in Vienna.

Millions of people die from treatable cancers because of a "chronic underinvestment" in radiotherapy -- which is highly cost-effective compared to many cancer drugs, the authors said.

"There is a widespread misconception that the costs of providing radiotherapy put it beyond the reach of all but the richest countries. Nothing could be further from the truth," said author Rifat Atun from Harvard University in Boston.

"Our work... clearly shows that not only can this essential service be deployed safely and high quality treatment delivered in low- and middle-income countries, but that scale-up of radiotherapy capacity is a feasible and highly cost-effective investment."

The researchers found that in 2035, more than 12 million new cancer patients could benefit from radiotherapy -- access to the treatment is currently restricted to about 40-60 percent.

The situation is worst in poor countries, where up to nine out of 10 people have no access to radiotherapy. In many countries in Africa it is "virtually non-existent", and 40 countries have no radiotherapy facilities at all.

"Even in high-income countries like Canada, Australia and the UK, numbers of radiotherapy facilities, equipment and trained staff are inadequate," said a press statement.

The study authors measured the shortfall in access to radiotherapy by country and globally, based on current and projected needs from today to 2035.

The estimated cost of $97 billion at the lower end of the scale, is equivalent to the price of about 230 Airbus A380s, or the budget for building and running the International Space Station for 10 years.

According to the UN's World Health Organization, there were about 14 million new cancer cases in 2012, and 8.2 million deaths.

This is likely to rise to 22 million new cases per year within two decades.