Genes play bigger role in causing cancer: researchers

CBC News - Genes play bigger role in causing cancer: researchers: "Genes play bigger role in causing cancer: researchers
Last Updated Fri Jul 14 07:40:22 2000

STOCKHOLM - Researchers say our genes cause more cancers than they thought but environmental factors are still the bigger cause.

Scientists used to think that our genes were responsible for causing about 10 to 20 per cent of cancers.

But a new study by researchers in Scandinavia says genes increase the risk of getting prostate cancer by 42 per cent, 35 per cent for colorectal cancer and 27 per cent for breast cancer.

The researchers, led by Paul Lichtenstein at the Karolinska Institute in Stockholm, examined the role of genes and cancer in 44,788 sets of twins in Sweden, Denmark and Finland.

They found identical twins have a greater chance of developing the same cancer than fraternal twins. That's because identical twins have identical sets of genes while fraternal twins are no more alike than other siblings.

Scientists expect the recently-completed human genome map will lead to cures for genetic diseases.

Cancer that isn't inherited is caused by environmental factors, like what we eat, where we work and whether we smoke.

The team's study appears in Thursday's New England Journal of Medicine.

The Scandinavian team limited its study to the three most common types of cancer but hope to expand the study to include 10 more types of cancer as more information becomes available."