All the gadgets, bottles, wires and devices that are part of the new equipment at the Department of Pathology look like something out of a cartoon. However, David Scheie, a consultant, and Linea Melchior, a molecular biologist, do not, for one second, doubt that the newly purchased chip-based technology is a breakthrough for cancer diagnostics.
"The new chip has given us new possibilities to establish a precise and quick diagnosis using DNA methylation. We can find a tumour’s methylation fingerprint and compare this with the profiles of all known tumours via a database kept in Heidelberg, Germany. This is truly great progress," said David Scheie.
Integrated cancer diagnostics
"The new method is building a bridge between classic tissue typing in pathology, where we look at the histology of the tumour in a microscope, and a modern methylation analysis which shows the molecular expression and epigenetics in the tumour. This is integrated cancer diagnostics, and now that we have the equipment to carry out the analysis and to draw up the profile, we can establish the correct diagnosis within just one week, and physicians can initiate the right treatment from the very beginning. This is a win-win situation for us all," said David Scheie.
The new technology has primarily been taken into use in diagnostic evaluation of children with brain cancer in cases where the tumours are difficult to define and predict. However, the technology will also be used in diagnostic evaluation of adult cancer patients when it is difficult to establish a diagnosis with traditional analysis methods. Previously, it could take up to six weeks to get test results from a tissue sample and establish a diagnosis in complicated cases. Now it only takes a week after taking the tissue sample.
Linea Melchior is just as excited about the new chip technology as her colleague.
"Think about how chip technology has revolutionised modern smartphones. This chip will have the same impact on pathology. It means a lot to patients and makes them feel safe. Not only because it provides a better foundation for choosing the right treatment in good time, but also because we can make a better prognosis using the classification of known tumours. It's all about providing correct and adequate treatment without over treating, particularly with regard to children with cancer, where incorrect treatment can have consequences later in life and cause damage, which again can lead to cancer or some other disease," said Linea Melchior.
Rouges' gallery of tumours
The tissue sample used to run the analysis is very small, and all it takes is 300 nano-grammes of DNA to achieve a profile with 850,000 pieces of information. The sample is placed directly on the methylation chip in a holder the size of a small fingernail. Just one small chip can run eight different tissue sample analyses at a time.
"A tumour doesn't look like normal tissue in the sense that the control mechanisms of the cell have been put out of operation. This is the weapon of cancer. It's constantly searching for new ways to grow and spread, and in this process it can accumulate mutations as well as turn genes on and off by means of methylation of the cells’ DNA. Therefore, it's so important that we look at the entire picture of the tumour; its methylation, location and histology, so that we get the most detailed description of its face, almost like a rogues' gallery when it’s compared with a police database. This is where the chip analysis comes into play, because it can help us recognise a tumour from among its many different faces," said Linea Melchior.
New methods with great perspectives
Every year, Rigshospitalet receives up to 40 children with variations of brain cancer where the chip will be able to make a difference in the diagnostic evaluation. Even though the method of analysis will initially be used in diagnostic evaluation of brain cancer, experts expect that they will soon be applying this method to other tumours such as sarcomas and meningiomas. With this expansion, the number of analyses using the chip will increase significantly over the coming years.
International colleagues in Heidelberg have built a database that gathers profiles of all known tumours, and because tumours are constantly developing and changing, many tumours have yet to be discovered. When a tumour profile has been analysed with the chip, Linea Melchior and her colleagues at the Department of Pathology can upload the data to Heidelberg, which then compares the profile with the other, known tumour profiles. This data also helps ensure that the database can continue to cover an increasing number of variations of tumours – to benefit future cancer diagnostics and treatment.