Circulating tumor DNA-based molecular residual disease detection and recurrence monitoring in patients with advanced or metastatic anal squamous cell carcinoma.

Authors

null

Georges Azzi

Holy Cross Medical Group, Michael and Dianne Bienes Comprehensive Cancer Center, Fort Lauderdale, FL

Georges Azzi , Mehrad Tavallai , Gregory P. Botta , Mohamedtaki Abdulaziz Tejani , Diana L. Hanna , Adham Adel Jurdi , Griffin Budde , Shifra Krinshpun , Minu Maninder , Vasily N. Aushev , Perry Olshan , Paul R. Billings , Alexey Aleshin , Pashtoon Murtaza Kasi

Organizations

Holy Cross Medical Group, Michael and Dianne Bienes Comprehensive Cancer Center, Fort Lauderdale, FL, Natera, Inc., San Carlos, CA, UCSD Moores Cancer Center, La Jolla, CA, Univ of Rochester Medcl Ctr, Orland, NY, Keck Hospital of USC, Los Angeles, CA, Austin Cancer Center, Austin, TX, Natera, Inc., Austin, TX, Omicia, Oakland, CA, University Of Iowa, Iowa City, IA

Research Funding

No funding received

Background: For patients with anal squamous cell carcinoma (ASCC), the current standard of care involves curative-intent definitive chemoradiation. For those that recur locally, salvage surgery maybe a consideration. ASCC, however, still lacks a non-invasive blood-based biomarker, which can be of value in this patient population for monitoring recurrence and/or response to immunotherapy later. Circulating tumor DNA (ctDNA) is a promising non-invasive tool to assess molecular residual disease (MRD) and recurrence in ASCC. Here, we evaluated real-world utility of ctDNA status to identify MRD and recurrence in ASCC patients across all stages. Methods: This is a retrospective analysis of patients with any stage ASCC receiving SOC or/and immunotherapy with immune checkpoint inhibitors. A personalized tumor-informed PCR/NGS-based assay (Signatera) was used for ctDNA detection, in the pre/on/post-treatment and surveillance setting. Results: In this study, plasma samples (n=105) were collected from 25 ASCC patients (13 females, 12 males; median age 66 years) at various timepoints for a median follow-up of 315 days (range: 59-1717), post-diagnosis; 12 patients were HPV-positive, 1 patient was HPV-negative, and 12 had unknown HPV status; 88% (22/25) of the patients had serial timepoints (≥2) available. ctDNA-positivity rates, test results, and ctDNA quantification by stage are summarized in Table. The quantitated ctDNA values (mean tumor molecules (MTM)/mL) increased in concordance with the stage of the disease, with values trending higher in stage III and IV. In addition, complete clinical outcome information was available for 22/25 patients at the time of releasing this data. Of the 96 plasma samples drawn from these patients, 68 (70%) were in the surveillance setting (post-definitive therapy). No recurrences were observed among 15 patients who cleared ctDNA on treatment and/or tested negative post-treatment, whereas, 6/7 ctDNA-positive patients were confirmed to have disease recurrence and 1 was pending confirmatory imaging. This often predated recurrence on scans. Conclusions: Measuring and monitoring MRD in patients with ASCC is feasible and has the potential to impact clinical decision making. Our study is the first to set the benchmark for the feasibility of using a tumor-informed assay in ASCC. Larger prospective studies are needed to explore the clinical utility of ctDNA status to guide disease surveillance and management of ASCC.

StagePositivity Rate, n/N (%)

(patient)
ctDNA Results

(plasma)
Quantity of ctDNA (MTM/mL)
Negative
Positive
Mean
Median
Range
I/II
3/6 (50)
23
11
1.83
1.58
0.05-1.83
III
4/13 (30.8)
43
12
18.77
2.79
0.2-67.75
IV
5/6 (83.3)
7
9
129.27
28.33
0.12-556.07

Disclaimer

This material on this page is ©2024 American Society of Clinical Oncology, all rights reserved. Licensing available upon request. For more information, please contact licensing@asco.org

Abstract Details

Meeting

2022 ASCO Gastrointestinal Cancers Symposium

Session Type

Poster Session

Session Title

Poster Session C: Cancers of the Colon, Rectum, and Anus

Track

Colorectal Cancer,Anal Cancer

Sub Track

Translational Research

DOI

10.1200/JCO.2022.40.4_suppl.006

Abstract #

6

Poster Bd #

A7

Abstract Disclosures