KEY TAKEAWAYS
- The combined analysis aimed to investigate the two adjuvant trials for assessing the prognostic potential of ctDNA as a biomarker for pts resectable stage III colon cancer.
- Immunoscore® and ctDNA were proven as independent biomarkers in stage III colon cancer.
Immunoscore® and Circulating tumor DNA (ctDNA) are key players in improving prognosis and tailoring the adjuvant treatments in patients (pts) resected from stage III colon cancer. This study analyzed both, pts randomized in the phase III IDEA-France and HORG trials, to determine their respective prognostic value.
Julien Taieb and the team conducted a combined analysis of trials (NCT00958737 and NCT01308066) to investigate circulating tumor DNA (ctDNA) and assess its prognostic value in terms of time to recurrence (TTR) and overall survival (OS) in pts with stage III colon cancer.
Researchers enrolled 554 pts with available ctDNA results, of whom 445 (80.3%) tested negative for ctDNA, while 109 (19.7%) tested positive.
A higher prevalence of T4 and N2 stages in ctDNA-positive pts vs ctDNA-negative pts (58% vs. 38%, P<0.01) was indicated by baseline characteristics.
Over a median follow-up period of 6.6 years, ctDNA-positive pts exhibited a significantly lower 2-year TTR rate of 43.5% (95% CI 34.1-52.6), whereas ctDNA-negative pts showed a higher rate of 88.1% (95% CI 84.7-90.8) (P<0.0001). Multivariable analysis confirmed ctDNA as an independent prognostic marker for both TTR (adjusted HR=5.21, 95% CI 3.59-7.58, P<0.001) and OS (adjusted HR=4.74, 95% CI 3.33-6.74, P<0.001).
The ctDNA remained the most significant prognostic factor across various disease stages, treatment durations (3 or 6 months), and Immunoscore® categories.
However, Immunoscore® did not demonstrate prognostic value in ctDNA-positive pts but continued to be a significant prognostic tool in ctDNA-negative pts. This highlighted the distinctive prognostic potential of ctDNA and Immunoscore® in stage III colon cancer, with evident ctDNA being consistently superior in predicting outcomes irrespective of other clinical variables.
The study reported the combined analysis of two adjuvant trials focusing on pts with stage III colon cancer, about 19.7% of pts tested positive for post-surgery ctDNA, which was established as a significant independent prognostic marker. Validating, Immunoscore® as an independent prognostic marker specifically among the 80.3% of pts who tested negative for ctDNA.
The trial was sponsored by GERCOR – Multidisciplinary Oncology Cooperative Group.
Source: https://cslide.ctimeetingtech.com/esmogi24hybrid/attendee/confcal/show/session/28
Clinical Trials: https://www.clinicaltrials.gov/study/NCT00958737
Taieb J, Souglakos I, Boukovinas I, et al. (2024). “Combined analyses of ctDNA and Immunoscore in stage III colon cancer pts: A post hoc analysis of the IDEA-France and -Greece trials.” Presented at ESMO-GI 2024, (Abstract 7MO)
