Genetic variation offers new way to spot the most dangerous childhood cancers

Date: Jan-29-2015 New research published in the journal Nature Communications suggests

that looking at genetic variation rather than the presence of individual mutations

might be a better way to identify the most malignant tumors in childhood cancers.

Measuring microvariations in tumor cells could one day help decide how strong a treatment needs to be to save the life of a child with aggressive cancer.

The researchers, from Lund University in Sweden, say their study explains why -

despite much research - for many types of childhood cancer it has been difficult to

predict which patients are more likely to experience recurrence of their cancer.

It is already well-known that in adult cancers, genetic variation is greater in

tumor cells than in healthy cells.

This makes sense when one considers that in cancer, when cells divide, the

chromosomes break up and recombine in odd ways, get muddled and end up in the wrong

place.

However, it has not been clear whether this also happens in childhood cancers -

and whether genetic variability in tumors is linked to aggressiveness.

The study confirms both of these are the case, as senior author David Gisselsson

Nord, an associate professor at Lund who leads a group investigating genomic

instability in childhood cancer, explains:

"Tumors in children are also genetically unstable, and the greater the variation

between the cells, the more malignant the cancer."

The most aggressive cancers were the ones with the most genetic variation

For their study, the team investigated 44 cases of Wilms' tumor, the most common

type of kidney cancer in children.

All the young patients had received chemotherapy and most recovered, but

unfortunately in some cases the cancer spread and the patients died. The study shows

these patients had the most genetic variation in their tumors.

Previously, researchers had been trying to predict which cases were the most

aggressive by looking for certain features - such as mutations - in a single sample

from each patient, Prof. Gisselsson Nord explains.

"However, when there is so much variation between the cells, one sample is not

enough to determine the properties of the tumor," he adds.

But thankfully, this does not mean you have to take lots of samples to assess

genetic variation. The team found it was enough to take a sample no bigger than a

millimeter across and assess genetic variation between cells - the extent of

"microvariations" as they called them.

'An entirely new way of assessing how dangerous a tumor is'

Microvariations are much better predictors of the risk of metastasis and death

than the presence of individual mutations, says Prof. Gisselsson Nord, who concludes,

"this is an entirely new way of assessing how dangerous a tumor is."

The researchers suggest microvariations are the foundation for the bigger changes

that eventually lead to cancer recurrence and spread.

The team now plans to carry out a large study of all new cases of kidney cancer in

children in Europe over the next 5 years.

Should the larger study confirm the

findings of this small study, then an assessment of microvariations in tumor cells

could become a way to decide how strong a treatment needs to be to save a young

patient's life.

Meanwhile, Medical News Today recently learned about a study published in

the journal Genes and Development that suggests a gene called ATDC may explain why pancreatic cancer is so aggressive.

The researchers found the gene plays an important role in helping pre-invasive

pancreatic tumors progress to a metastatic state.

Written by Catharine Paddock PhD

Courtesy: Medical News Today Note: Any medical information available in this news section is not intended as a substitute for informed medical advice and you should not take any action before consulting with a health care professional.