Impact of Consolidation Durvalumab on Local Control Following Chemoradiotherapy for Non-Small Cell Lung Cancer

The PACIFIC trial demonstrated that durvalumab after concurrent chemoradiotherapy (CCRT) improves survival in locally advanced non-small cell lung cancer (NSCLC), but its impact on in-field local control is unclear. We reviewed outcomes with and without consolidation durvalumab to evaluate its effect on local control of treated tumors and lymph nodes.

We reviewed patients with locally advanced NSCLC who underwent staging FDG-PET and CCRT with or without consolidation durvalumab between 2007 and 2023. Patients with progression or death within 6 weeks postradiotherapy were excluded. Lesions were categorized as high- or low-risk using a volume cutoff of 25 cc. Kaplan-Meier and competing risks analyses were used to evaluate progression-free survival (PFS), overall survival (OS), and local progression. Tumor control probability (TCP) modeling was performed to characterize the association between lesion volume and local control.

Among 233 patients with 696 irradiated lesions, 88 patients (38%) received durvalumab. Median follow-up was 70 months overall and 44 months with durvalumab. Durvalumab receipt was associated with improved PFS (median 16 vs. 11 months, P = .011) and improved OS (median 50 vs. 30 months, P = .042). Durvalumab was not significantly associated with local recurrence rate on a patient level (2-year recurrence rate 12% vs. 17%, P = .361). At the lesion level, the 2-year recurrence rate was 6% overall, and high-risk lesions had greater recurrence risk (19% vs. 2%, P < .001).

Many patients with LA-NSCLC have little risk of in-field recurrence after chemoradiotherapy, with or without consolidation durvalumab. Bulky lesions remain prone to failure, highlighting the need for improved local control strategies in high-risk disease.