QUEENSLAND scientists may have uncovered the key to why tall people are at increased risk of cancer.

Researchers have long known that taller people are more likely to be diagnosed with a range of cancers, including breast, pancreatic, thyroid and bowel cancer compared to their vertically challenged colleagues.

A team led by Andrew Brooks, of the University of Queensland, has found a variant in the growth hormone receptor gene also promotes lung cancer.

The discovery — part of a growing body of evidence into the long and short of how stature affects health — is expected to apply to other cancers and could lead to new drugs to inhibit the spread of the disease.

Growth hormone receptors send signals to cells, regulating a range of factors, including height, fertility, metabolism, brain function and immunity. Previous studies of dwarfs born with a defect in the growth hormone receptor gene, rendering it inactive and unable to communicate with cells, have found they do not develop cancer.

media_camera University of Queensland researcher Dr Andrew Brooks has found why tall people are at increased risk of cancer.

By researching lung cancer cells in the laboratory, Dr Brooks and colleagues found a mechanism by which a particular variant of the growth hormone receptor gene causes prolonged signalling to cells, telling them to divide and grow.

“That’s the same signalling pathway we see in most cancers,” Dr Brooks said.

“We don’t think it’s going to be the main driver of the cancer but if you’ve got other things increasing your risk of cancer, like if you’re a smoker, as well as having excess growth hormone or a genetic change in the growth hormone receptor, your risk is then elevated.”

Dr Brooks, who towers over all but one of his laboratory staff at 183cm tall, said that having a better knowledge of growth hormone receptor signalling gave scientists a new target for developing drugs to treat cancer.

“My group is already looking at small molecules that specifically reduce the signalling from the growth hormone receptor,” he said. “We would hope that they could work together with other treatments to slow the progression of the cancer.

“Of course that will be dependent on a long process of clinical trials to validate the effectiveness of this approach.”

His colleague Dr Yash Chhabra said he hoped the variant in the growth hormone receptor gene they studied would be included in future DNA tests for people wanting to explore their disease risk.

The research is published in the scientific journal, Oncogene.

Originally published as Tall people at higher risk of cancer