Soon, it will become a lot simpler to diagnose gastrointestinal (GI) cancers as scientists have come up with two new blood tests for the same.
A research team led by Joost Louwagie, from the company OncoMethylome Sciences in Liege, Belgium collected blood before surgery from 193 patients known to have colorectal cancer, as well as from 688 controls undergoing colonoscopy for cancer screening.
DNA was extracted from the blood plasma and tested for the presence of DNA methylation of specific genes.
DNA methylation is involved in the regulation of protein expression, and methylation or silencing of key genes has been linked to the initiation and progression of tumours.
"This test has potential to provide a better balance of performance, cost-effectiveness and patient compliance than other options currently available for colorectal cancer screening," said Louwagie.
"We optimised the methods of DNA extraction and methylation detection so that we could detect low levels of methylated genes in people with colorectal cance and we were able to find a high frequency of two newly reported methylation genes, SYNE1 and FOXE1, in colorectal cancer patients. The same methylation genes occurred infrequently in non-cancerous individuals," he added.
In a second study, German researchers have developed another blood test that helps diagnose tumours in patients with colon, rectal, or gastric cancers.
Professor Ulrike Stein, from the ECRC Charite University of Medicine, and the Max-Delbrueck-Centre for Molecular Medicine says that the test can also predict the likelihood of metastatic disease in patients after diagnosis of these cancers.
Prof Stein and her team looked for the existence of an S100A4 transcript , by isolating RNA from blood plasma samples from patient with GI tumours. They collected daily blood samples from hospitalised and outpatients; 185 samples for colon cancer, 190 for rectal, and 91 for gastric cancer patients. They also analysed the blood of 51 age-matched, tumour-free volunteers.
"We found that S100A4 mRNA was present at significantly higher levels in the group of cancer patients, no matter whether they had colorectal or gastric cancer, than in the tumour-free control group and there were yet higher levels in the patients with metastases than in those where the disease had not yet metastasised," said Stein.
The findings were presented at Europe's largest cancer congress, in Berlin.