Revisiting margin adequacy in sublobar resection for pure ground-glass opacity adenocarcinomas

Pure ground-glass opacity (GGO) lesions have a favorable prognosis and are primarily treated with sublobar resection. Current guidelines uniformly define sufficient margins as greater than 2 cm or the size of the lesion, regardless of the lesion's characteristics. This study evaluates the prognostic impact of insufficient margins in sublobar resection for pure GGO adenocarcinomas.

Between 2009 and 2022, patients who underwent sublobar resection for pure GGO adenocarcinomas were retrospectively analyzed. The patients were divided into two groups based on the presence of adequate surgical margins, as defined by the National Comprehensive Cancer Network (NCCN) guidelines. A maximally selected log-rank test was used to explore alternative definitions of margin adequacy, while Cox proportional hazards analysis was utilized to assess the prognostic impact of margin adequacy, based on various definitions, on freedom from recurrence (FFR).

Among the 284 patients, 158 (55.6 %) exhibited sufficient margins, while 126 (44.4 %) had insufficient margins. The overall recurrence rate was 1.8 %, with no significant difference observed between the groups (p = 0.530). The 5-year FFR was 97.9 % for the insufficient margin group and 98.2 % for the sufficient margin group. Margin adequacy, as determined by NCCN guidelines, showed no prognostic impact. However, an alternative definition of margin, characterized by a length of 5 mm or a margin-to-GGO size ratio of 0.25, was identified as a significant risk factor for FFR (HR = 7.80, p = 0.025).

Current margin recommendations may be overly stringent for pure GGO lesions and emphasize the need for tailored margins.