THE NATIONAL CANCER INSTITUTE REGINA ELENA, IN COLLABORATION WITH EUROFINS GENOMA GROUP LABORATORIES, SHOWS HOW LIQUID BIOPSY IN COLON CANCER CAN PROVIDE COMPLEMENTARY ANSWERS TO THOSE OF OTHER BIOLOGICAL TESTS AND IMPROVE THE CURRENT DIAGNOSTIC STRATEGIES.
Early diagnosis of colorectal carcinoma is a need deeply felt by both patients and health authorities. Many patient rights associations (eg Digestive Cancers Europe; https://www.digestivecancers.eu) have long been pressing for new and more accurate diagnostic tests to be adopted in clinical practice. Liquid Biopsy is one of these tests, and is based on the detection of circulating free DNA (cfDNA) released into blood by cancer cells.
The study conducted in collaboration with Regina Elena Institute, had the analysis of specific regions of the genome as main aim, applying massively parallel sequencing (Next Generation Sequencing, NGS), and an ultra-sensitive method not yet used in the routine diagnostics (the ‘digital PCR’). Thanks to the union of these methods, it has been possible to reveal tiny amounts of altered tumor cfDNA in the blood (even 500 times lower than that found in patients with advanced tumors) since the day of the surgical operation for the removal of the primary tumor.
The study results suggest that these assays reveal the presence of relatively small tumors (up to a minimum of 3 cm in diameter) in almost 2/3 of patients. The number of patients analyzed is still insufficient, but the results are promising, and above all, they show that the technologies are mature to achieve even ambitious results. In addition, the clinical usefulness of the liquid biopsy was also highlighted in post-surgical follow-up, in patients who have persistence of neoplastic alterations in the blood that tend to have a less favorable outcome, with relapses and / or early metastasis. In fact, it would seem possible to highlight patients whom the surgeon declares cured, but who instead still have some small elusive (not visible with CT and PET) and cryptic (we do not know where it is) site of disease (minimal residual disease) somewhere. To the full advantage of the diagnostic abilities of the test, with all due caution, the liquid biopsy is nevertheless an important weapon, because from the early stages of the tumor it can give us very useful indications as to tumor vulnerabilities. This study suggests that the early diagnosis of colorectal cancers is expected to quickly change in the coming years thanks to the liquid biopsy, and hopefully more and more tumors will reach the operating table in initial conditions, allowing radical and definitive treatments.