Bigger, aging population boosts cancer incidence

An aging and bigger world population is being translated in more breast and lung cancer cases, which doubled since 1975, a report just published by Cancer Research UK shows.

The organisation said the increase in the number of cases reflects the world's growing population and the fact that people are living longer in all parts of the globe.

"The proportion of the world's population aged 60 and over currently stands at 10 per cent but is expected to more than double to 22 per cent by 2050," it said.

Cancer Research UK said most forms of cancer are linked to age and the likelihood is that the older you are the higher the risk, leading to more cases of cancer among older populations.

In Malta the rates of lung cancer and female breast cancer have increased slightly between 1994 and 2003. Statistics held by the National Cancer Registry - which started gathering data for the whole population in 1990 - show that the incidence of female lung cancer rose from 14 in 1994 to 22 in 2003, male lung cancer increased from 102 to 111 and female breast cancer went up from 180 to 219.

More than 1.1 million cases of breast cancer are diagnosed world-wide every year, up from about 500,000 cases in 1975.

"Most of the increase is accounted for by the higher life expectancy among women world-wide, together with the world's growing population - around four billion in 1975, it is currently estimated to be 6.3 billion," the British organisation said.

Although age is a determinant factor in cancer incidence, smoking is a far more important risk factor in relation to lung cancer.

"Lung cancer has become the most commonly diagnosed cancer in the world, with approximately 1.4 million new cases every year compared to fewer than 600,000 in 1975. Most of these are thought to be smoking-related," it said.

The British organisation said lung cancer rates follow smoking rates, with incidence of the disease tending to peak about 20 years after the proportion of people smoking peaks. In regions where the prevalence of smoking has increased, including eastern Asia, central America and southeast Asia, there will be big increases in the numbers of people diagnosed with lung cancer over the next 20 years, it said.

The good news lay in the fact that the rates of stomach cancer, the most common type of cancer in 1975, were falling in association with improved home hygiene and food preservation. Cervical screening programmes in developed countries had significantly reduced the number of women diagnosed with cervical cancer. However, cases were still rising in the fast-growing populations of developing countries.

Cancer Research UK medical director John Toy said the statistics show that cancer is still essentially a major disease of the developed world. In fact, he said, only four per cent of deaths in Africa were due to cancer, as opposed to 19 per cent in Europe.

"The developing world can learn from past mistakes: tackling the smoking habit, for example, would minimise future lung cancer cases and substantially reduce the future cancer burden in developing countries," he said.

Prof. Toy said that although the figures show a persistent increase in the number of people being diagnosed with cancer, developing and refining new treatments would continue to improve the chances of surviving the disease. Thanks to such research many more people diagnosed with cancer this year would survive compared to those so diagnosed in 1975.