DiagnoCure Inc. reported that results of a new study were presented on Sunday, June 2, during the 2013 American Society of Clinical Oncology (ASCO) Annual Meeting held in Chicago, Illinois. The VITAR retrospective study (Validating Indicators To Associate Recurrence) had been designed to assess the relationship between GCC gene expression in formalin fixed (FFPE) LNs and time to recurrence (TTR) in stage II Colon Cancer patients not treated with adjuvant chemotherapy. The second phase (called VITAR II), the results of which were presented at the 2013 ASCO meeting, focused on the positive lymph node ratio (LNR), defined as the number of nodes in which cancer cells were identified with the GCC assay, divided by the total number of nodes examined to provide recurrence risk stratification.

On a validation set including 463 untreated stage II (T3N0) colon cancer patients from North American and European sites, the study showed that molecular staging based on GCC LNR status was able to predict higher recurrence risk for 195 patients (42%) treated by surgery alone. All patients had not been treated with adjuvant chemotherapy mainly because their lymph nodes appeared cancer-free by examination under the microscope, yet 10% of them had a disease recurrence or died from cancer afterwards. Outcome associations were also strengthened when considering a 3-level GCC categorization.

In the final study cohort (n=366), the Previstage TM GCC test classified 21.8% of patients as having a high risk of recurrence following surgery, 17.5% at intermediate risk and 60.7% of patients at low risk of recurrence. In this subset analysis, the 5-year recurrence risk was estimated at 8% and 22% for the low and high risk groups respectively, with a hazard ratio of 2.7 (p=0.006) supporting the prognostic capabilities of the GCC nodal status as an independent risk factor.