ESMO WCGIC 2023 | The role of tissue and liquid biopsies in managing colorectal cancer

Say the prognostic power of these essays are on a completely different scale compared to the classical prognostic factors. We have crushed our heads for 20/30 years to define a better prognosis within the TNM staging system based upon the grading, based on the vascular invasion, lymphatic invasion, neuroinvasion clinical presentation and say the bottom line of all that literature is that these factors account for a maximum of 5 to 7 to 8 to 10% maximum number of nodes taken out, you know, maximum difference of patients having the factor has composed of a patient that not having the prognostic factor. Now here we we are talking about the 70%, 80% more. So again cannot be compared and that’s a great point. The second great point is that also has a predictive value and the predictivity has been illustrated very nicely by Jeanne Tie both at this debate as well as at his last year along with her publication of the New England Journal of Medicine, where she showed that in the experimental arm where if the patient postoperative is ctDNA negative and is not treated, the three year DFS rate is 90%. If if the patient is positive and is treated, the three DFS is 86 to 88%. But the most important point is that if the patient positive continues to be positive after adjuvant therapy, the relapse rate will be 20% at one year, 20% at one year. Whereas if the patient is positive and converted to negative, the three year, not the one year relapse free survival is 90%, does that mean that we cure 70% of patients with adjuvant? That’s an open question.