Genome study targets cancer categories
7 Aug 2014
New research suggests that 10% of cancers should be reclassified, allowing patients to receive more suitable treatments.
A team of scientists at the University of California, San Francisco (UCSF) has suggested that as many as 10% of cancer patients could be more accurately diagnosed if their tumours were defined by cellular and molecular criteria - rather than by the tissues in which the cancer originated.
The study has been published in the online journal Cell.
As part of the research, scientists analysed both the molecular and genetic characteristics of more than 3,500 tumour samples of 12 different cancer types using multiple genomic technology platforms.
“We’re just appreciating the tip of the iceberg when considering the potential of this multi-platform type of genomic analysis
Co-lead author Christopher Benz
Traditionally, cancers are categorised by their ’tissue of origin’ - however, tissues comprise many different types of cells, suggesting accurate diagnosis is not as straightforward as previously thought.
The UCSF study indicates that in many cases the type of cell affected by cancer may be a more useful guide to treatment than the tissue in which a tumour originates.
“This genomic study not only challenges our existing system of classifying cancers based on tissue type, but also provides a massive new data resource for further exploration, as well as a comprehensive list of the molecular features distinguishing each of the newly described cancer classes,” said co-senior author Christopher Benz.
The scientists were also able to confirm known differences between subtypes of breast cancer known as ’basal-like’ and ’luminal’ cancers.
Having compared these types of cancer with several others, the researchers were able to discover that basal-like breast cancers constitute their own distinct class.
These types of cancers, which are commonly referred to as ’triple-negative’ cancers, are particularly aggressive, and are most prevalent among African-American women and younger women.
“Even though these basal-like cancers arise in the breast, on the molecular level they have more in common with ovarian cancers and cancers of squamous-cell origin than with other subtypes of breast cancer,” said co-lead author Christina Yau.
According to Benz, the number of patients eligible for reclassification will swell when more tumour samples and additional tumour types are included in the Pan-Cancer project’s next round of analysis, which is expected to include more than 20 different tumour types.
“We’re just appreciating the tip of the iceberg when considering the potential of this multi-platform type of genomic analysis,” Benz said.
“It could be that as many as 30 or 50 percent of cancers need to be reclassified.”
