YO27 - Negative Predicting Value of Longitudinal Undetectable MRD in Maintenance Immunotherapy for Advanced Lung Cancer Patients: A Case Report

Case summary

Background: According to current guideline recommendations, the duration of maintenance immunotherapy is set at two years for patients with advanced non-small cell lung cancer (NSCLC) without driver gene mutations. Nevertheless, the determination of the two-year duration is not based on rigorous evidence-based medical evaluation. The generalizability of this approach for such patients is still debatable and remains a contentious issue.

Case description: A 66-year-old male patient was diagnosed with stage IVB (T4N2M1c) lung adenocarcinoma, with immunohistochemistry revealing PD-L1 expression at 85%. Next-generation sequencing identified no driver gene mutations. From September 2021 to May 2022, the patient underwent first-line treatment, comprising the PC regimen, with or without immunotherapy, followed by longitudinal MRD detections. The treatment efficacy was evaluated as a partial response (PR) upon completion of a nine-cycle regimen. In October 2022, maintenance immunotherapy was discontinued due to immune-related adverse reactions. The patient achieved MRD-negative status for the first time in June 2022, and subsequent regular follow-ups confirmed persistently negative MRD results. Concurrent imaging examinations corroborated disease stability, aligning with the negative MRD findings. Notably, the patient did not receive maintenance immunotherapy for two years, yet the lesions remained stable.

Conclusions: Based on the longitudinal MRD test results combined with imageological examinations, patients with advanced NSCLC might be stratified into different risk categories, thereby facilitating the customization of individualized treatment plans. This approach might tailor the de-escalation or discontinuation of maintenance immunotherapy in patients who consistently exhibit an MRD-negative status, thus minimizing medication-related adverse effects and unnecessary financial burdens for those at low risk of recurrence which highlights the significant negative predicting value of longitudinal undetectable MRD in this domain.

Clinical trial identification

Editorial acknowledgement