05 September 2016
ByAppeared in BioNews 867
The discovery of these specific biomarkers may allow clinicians to tailor treatment for the patient, and be crucial in helping some patients avoid cancer treatments which can cause undesirable effects.
'The history of cancer treatment is filled with overreaction,' said principal investigator Professor Gary Karpen, a senior scientist at the University of California, Berkeley in the USA. 'It is part of the ethics of cancer treatment to err on the side of overtreatment, but these treatments have serious side effects associated with them.'
Currently, doctors rely on information such as the stage and grade of cancer tumours to decide upon suitable treatment. However, there has been no reliable way to predict at an early stage of cancer development how patients will respond to therapy.
Researchers at the Lawrence Berkeley National Laboratory in California screened public datasets about clinical cancer tumour samples for 31 genes associated with chromosomal instability. Overexpression of these genes is linked to chromosomal instability, where chromosomes break during cell division, has long been recognised as a hallmark of cancer.
Yet although these genes are associated with poor patient survival, they are also related to a more positive response to gene-damaging treatments like chemotherapy and radiation therapy.
Conversely, patients with lower expression may have a better prognosis but find these therapies as ineffective.
The researchers identified 14 genes which were consistently overexpressed in cancer tissue. These results were derived from thousands of samples from at least a dozen different types of cancer, provided by the National Center for Biotechnology Information, the Broad Institute and other institutions.
It is hoped that this research may pave the way for more precision medicine and make it easier for future doctors to choose appropriate therapies for patients.
Dr Karpen explained: 'Chromosome instability is such a basic part of how cancer progresses that this approach gives us an opportunity to use the score in many different cancer types such as lung and breast, and by providing information to patients about the choices they might make with respect to therapy, we think this could make a very important contribution to the field.'
Further investigation and validation of findings will have to be done before it can be applied to the clinical field. The researchers note that they found no link between very high levels of genome instability and improved patient survival without adjuvant treatments, and so will need to establish a reliable threshold of genome instability so that doctors and patients can make informed decisions.