Incremental Prognostic Value of Preoperative SUVmax Beyond Size-Based T Descriptors in Pathologic Stage IA Lung Adenocarcinoma.

Abstract

This study aimed to identify which single clinicopathologic or metabolic indicator most effectively defines a high-risk subgroup beyond size-based T descriptors. The study retrospectively analyzed 1198 patients with pathologic stage IA lung adenocarcinoma who underwent lobectomy with mediastinal lymph node dissection between 2007 and 2021. The rule-in performance of each risk factor was assessed by comparing the 5-year cumulative incidence of recurrence in high-risk groups defined by the optimal threshold for each variable. Net reclassification improvement was used to quantify incremental prognostic value beyond T descriptors. The median follow-up period was 54 months (interquartile range [IQR], 35-76 months), and the overall 5-year cumulative incidence of recurrence was 4.4%. Among all the variables tested, SUVmax yielded the highest 5-year recurrence rate in its high-risk group: patients with an SUVmax of 6.0 or higher had a 5-year cumulative recurrence incidence of 25.4%. In the multivariable Fine-Gray analysis, SUVmax was the only variable that retained independent prognostic significance (adjusted subdistribution hazard ratio, 1.058; 95% confidence interval (CI), 1.022-1.095; P = 0.001) and the only factor that significantly improved risk reclassification beyond T descriptors in the categorical net reclassification improvement analysis (net reclassification improvement, 0.346; P  = 0.008). Among established prognostic factors, SUVmax demonstrated the most consistent rule-in performance for identifying patients with pathologic stage IA lung adenocarcinoma at elevated recurrence risk, providing incremental prognostic value beyond size-based T descriptors. An SUVmax threshold of ≥ 6.0 identified a subgroup with a 5-year cumulative incidence of recurrence exceeding 25%, who may warrant intensified surveillance and prospective evaluation in perioperative systemic therapy trials.