Jan 24, 2014

    Take cancer risk with a pinch of salt

    IT NEVER fails to do the trick.

    When I announce at the opening of many of my public lectures that "on average, every third person counted will eventually fall victim to cancer", I will hear gasps from the audience.

    One in three? That must be an exaggeration.

    Hardly. Not only will one in three Singaporeans develop cancer, but 30 per cent of Singaporeans may also die from it.

    This makes cancer deadlier than heart attacks or pneumonia.

    In the 1960s, less than 15 per cent of Singaporeans died of cancer. In the 2010s, this has doubled to 30 per cent.

    When the topic of Singapore's economic progress is discussed, citizens react with pride. The story is a familiar one. Less familiar, though, is the growth of cancer over the same period.

    Their parallel growth gives rise to two interesting questions: Is cancer a disease of modern society? Is there a link between the rise in economic performance and cancer incidence?

    Just a few generations ago, grandparents might not have known of many relatives or acquaintances dying from cancer. This is in sharp contrast with recent years, when one frequently hears of cancer diagnoses in relatives and friends.

    Cancer, however, is an ancient disease. Archaeologists have unveiled records of cancer-treatment methods in ancient Egypt.

    The increased incidence of cancer places a heavy burden on society. But it could be argued that its rise reflects improving social indices, such as rising life expectancy.

    Modern living exposes people to more cancer-causing agents, known as carcinogens. Tobacco smoking, increased alcohol use, environmental pollution and radiation exposure are factors that come to mind. But such factors would likely account for no more than a 2 per cent to 3 per cent increase in cancer incidence.

    The rise of cancer is due, to a longer extent, to the decrease in causes of death more common in the past. With improving health care, nutrition and environmental sanitation, scourges such as tuberculosis, malaria and dysentery have now been tamed.

    Cancer is a final frontier. These days, death is probably due to cancer, stroke or heart attack.

    The rise in life expectancy is closely related to economic development and improving social circumstances, but the risk of developing cancer increases with age.

    In the 1960s, life expectancy in Singapore hovered in the low 60s. Last year, life expectancy crossed 80. As most cases of cancer arise in people above the age of 50, there would be many more people at risk of developing cancer these days compared to 50 years ago.

    Contrast this with, say, Sub-Saharan Africa, where the average life expectancy is about 50: Most people would have died of other causes before they reached the age at which they would have been likely to develop cancer.

    The high incidence of cancer in Singapore arises from the paradoxical situation of having good living conditions. It is also due to better record-keeping.

    With improved medical technology and better access to good-quality medical care, most patients suffering from cancer in Singapore today would be accurately diagnosed. If patients die from the disease, modern technology enables systems to accurately capture the information and reflect it in the country's health statistics.

    In contrast, a quick survey of the causes of death of grandparents and great-grandparents here will frequently throw up answers such as "he died of old age" or "she was just old".

    However, many may have died from cancer, which went undiagnosed.

    A falsehood may arise when comparing the relatively high incidence of cancer in a developed country, such as Singapore, with that of a developing country. Cancer incidence in developing countries may be artificially low due to big gaps in data collection.

    In other words, cancer incidence is high in Singapore because its society has done well in many ways.

    That is, indeed, cold comfort.


    The writer is the medical director and consultant specialist in medical oncology at The Cancer Centre, a Singapore Medical Group clinic. This is an edited extract from his book, Cancer Cancel, which is available at Popular bookstores here.