Article - Hidden cancers detected by combining gen
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Combining genomic screening with whole-body scans has identified 16 hidden tumours in 30 people. The technique should help identify curable cancers in people who are genetically at-risk and save lives.
Advances in reading and understanding the genome have made it easier to identify people who are particularly susceptible to cancer. For example, people with mutations in the BRCA1 and BRCA2 genes are more likely to get breast cancer. But often this information isn’t particularly helpful. While some women with BRCA mutations opt for pre-emptive breast removal, there is little that can be done about some other genetic susceptibilities.
One of these, caused by mutations in a gene called tumour protein p53 (TP53), is present in around 1 in 10,000 people. It greatly increases the chances of getting a range of cancers, including in the breast and brain. About half the people who have such mutations develop a cancer by the age of 30.
“Genomics is revealing patterns of mutations that increase cancer susceptibility anywhere in the body, not just in one particular organ, but we haven’t known what to do with this information because how do you screen everything?” says David Thomas at the Garvan Institute of Medical Research in Sydney. “That’s where whole-body MRI could help.”
A team led by Thomas and his colleague Mandy Ballinger has found that such screening of people at genetic risk can detect hidden tumours before they turn deadly.
Curable tumours
The team performed head-to-toe MRI scans on 30 people aged between 18 and 62 with TP53 mutations. The scans detected three new, early-stage cancers, as well as two recurrences of previous cancers and 11 benign tumours.
Of the three new cancers, two were in the prostate and one was in the lower back, and all were still at a curable stage.
The researchers then analysed data from 578 people from six countries who have TP53 mutations and have had whole-body MRI scans. In total, they found that the technique had identified 35 curable, early-stage cancers, including in the breast, bowel, bone, prostate, lung, kidney and thyroid.
“As you can imagine, it’s an enormous relief for these people,” says Ballinger. Since the scanning study began in 2012, all but one of the 30 participants have chosen to continue getting annual, whole-body scans.
The early-onset cancer caused by TP53 mutations is called Li-Fraumeni syndrome. These mutations can be passed down from a person’s parents or can arise spontaneously in embryos.
“There’s extreme stress for families with Li-Fraumeni syndrome,” says Thomas. “Imagine being 20 years old, one of your parents has died of cancer, and your older siblings now have cancer and you’re wondering when you’re next.”
Natalie Coutts was one of the participants found to have benign tumours, in her uterus and kidneys, and says she is glad they were identified and removed. “I want every lump and bump investigated because there’s such a high risk of cancer,” she says. “I don’t care how many times I’m under the knife because I have children and I want to be around for them.”
Family risk
As well as benefiting people with Li-Fraumeni syndrome, regular whole-body MRI scans may help people with other susceptibility genes, like BRCA2, says Thomas. While BRCA2 mutations are typically associated with breast and ovarian cancer, they also seem to be linked to other cancers like sarcomas. “If you just do breast screening, you might miss a curable sarcoma in a person’s thigh,” Thomas says.
Although whole-body MRI is a promising tool for picking up new tumours in people with clear cancer risks, we still need to show that it leads to improved survival, says Nicholas Hayward at the QIMR Berghofer Medical Research Institute in Brisbane.
Testing the genomes of the whole population would be unwise at this stage, Hayward says. “Mainly because you’d find numerous mutations that may or may not increase cancer risk and that could cause unnecessary anxiety,” he says.
For the time being, it is better to reserve genetic screening for people with family or personal histories of cancer, Hayward says. “If someone has a family history of breast cancer, it might be useful to test for the BRCA mutations, but I don’t think we should be looking for mutations in every gene in everyone right now.”
https://www.newscientist.com/article/2142720-...-with-mri/