Characteristics of patients (pts) with disease relapse despite absence of molecular residual disease (MRD) after resection of colorectal oligometastases (CRM): Implications from PRECISION study.

Abstract

Listen

Translate article

3602 Background: Detection of MRD after curative-intent resection of CRM is prognostic for disease relapse and may guide decisions regarding adjuvant chemotherapy (ACT). However, some pts without MRD detected immediately after resection may also experience disease relapse. We explored the features of pts enrolled in a prospective multicenter study with disease relapse who did and did not have post-resection MRD. Methods: Pts with previously untreated resectable CRM scheduled for surgery were prospectively enrolled between March 2021 and October 2022. Pretreatment genomic alterations were assessed in circulating tumor DNA (ctDNA) by Guardant360, while MRD was assessed 4 weeks after resection with a methylation-based ctDNA MRD assay (Guardant Reveal). Characteristics of pts who were MRD negative but relapsed later were analyzed. Results: Of 118 eligible pts enrolled, pretreatment ctDNA was detected in 99 (84%), 62 (53%) of whom had poor genomic profile, defined as a mutation in BRAF, RAS, PIK3CA, and/or SMAD4. Of 110 pts who underwent surgery, postoperative MRD was detected in 35 (32%). With a median follow-up time of 11.0 months (m), 37 pts recurred, of whom 14 were MRD negative and 23 MRD positive. MRD negative pts were more likely to develop lung metastases (64.3% vs. 30.4%, p=0.09) but less likely to have liver metastases (21.4% vs. 60.9%, p=0.03). Median recurrence-free survival (RFS) of MRD-negative relapsed pts was longer than that of MRD positive pts (8.6 m vs. 3.5 m; hazard ratio [HR], 0.28 [95% CI, 0.13-0.58]). Among MRD-negative pts with recurrence, risk factors most associated with recurrence were a history of lymph node metastases (LNM) (odds ratio [OR], 6.20 [95% CI, 1.28-30.1]) and poor pre-operative genomic profile (OR, 3.85 [95% CI, 1.08-13.70]). Among all resected pts, LNM (HR, 2.55 [95% CI, 1.10–5.89]), poor genomic profile (HR, 2.97 [95% CI, 1.29–6.85]), and MRD positivity (HR, 6.36 [95% CI, 2.96–13.64]) were significantly associated with shorter RFS in multivariate analyses. Conclusions: Pts with a history of LNM or poor pre-operative genomic profile were at risk of recurrence despite the absence of MRD after curative-intent resection of CRM. Clinical trial information: UMIN000042490.