Authors: Arvind Dasari, Alisha Heather Bent, Kristin Alfaro-Munoz, Ryan W Huey, Benny Johnson, Michael Sangmin Lee, Maria Pia Morelli, Van K. Morris, Michael J. Overman, Christine Megerdichian Parseghian, Kanwal Pratap Singh Raghav, John Shen, Jason Willis, Timothy E. Newhook, Abhineet Uppal, Y. Nancy You, Tsuyoshi Konishi, George J. Chang, Scott Kopetz, Robert A. Wolff,
Published: 2023-06-04
DOI: 10.1200/jco.2023.41.16_suppl.3522
Source: Full article
3522 Background: Observational cohorts have shown that detection of circulating tumor DNA (ctDNA)-defined minimal residual disease (MRD) following curative intent therapy has very high specificity and positive predictive value for future radiographic recurrence with a lead time of over 9 months. However, such data have not incorporated rigorous clinical evaluation for concomitant recurrence, nor have they established the clinical utility of MRD monitoring after completion of curative intent therapy. Methods: Pts with stages II-IV CRC (6/1/19 - 12/31/22, data cutoff) treated with curative intent at MD Anderson Cancer Center were evaluated with a tumor-informed MRD assay (Signatera, Natera), as part of the institutional INTERCEPT program that aims to integrate MRD-based testing into CRC clinical care. Surveillance visits including scans and tumor markers were performed per established guidelines. ctDNA was recommended post-operatively and q3m with each surveillance visit. Pts and providers were informed of the results and subsequent clinical courses including additional radiologic testing for ctDNA+ MRD tests were tracked. Results: 1259 pts were included in the INTERCEPT program (median 57y, [21-93]; 55% male; stage% I-III/IV 69/31; colon/rectum% 61/39), with 1049 pts tested after curative intent surgery. Of these, 159/1049 pts (15%) had ctDNA+; distribution of pts, % (+ve/total) from time of such surgery in m was: 0 - 3 (54.6/43.8); 3-6 (21.3/30); 6-12 (24/33.2). Of the pts with ctDNA+ after surgery, 49 pts (32%) were ctDNA+ prior to or during adjuvant therapy and 86 (57%) during surveillance. Of the 86 pts who were ctDNA+ during surveillance, imaging revealed concomitant new metastases in 46 (53%); i.e. only 40 (47%) were true MRD+. A total of 191 imaging studies were done (range 1-4) within 90d of the initial ctDNA+ including 99 as routine surveillance concurrent with ctDNA testing and 92 as additional follow up based on results. Of 40 pts with true MRD, majority (27 pts, 67.5%) were enrolled onto ongoing MRD trials ( https://crcmrd.com/ ). Conclusions: Our experience provides support for the feasibility of incorporation of MRD testing as part of routine surveillance. ctDNA+ results trigger a high rate of reflex imaging and, as a result, 53% of ctDNA+ patients have concomitant new radiographic findings. While clinical trials are feasible in true MRD+ pts, eligibility criteria for these trials need to be carefully specified about adequate radiographic evaluation.