Lobectomy Is Associated with Better Outcomes than Sublobar Resection in Spread Through Air Spaces (STAS)–Positive T1 Lung Adenocarcinoma: A Propensity Score–Matched Analysis
Menée à partir de données portant sur 1 497 patients atteints d'un adénocarcinome du poumon de stade T1N0M0, cette étude met en évidence l'efficacité, du point de vue des taux de récidive, d'une lobectomie par rapport à une résection sublobaire chez les patients présentant une dissémination aérienne de type STAS (Spread through air spaces), puis analyse l'intérêt des sections tissulaires congelées pour détecter ce type d'envahissement tumoral
Introduction : Spread through air spaces (STAS) is a form of invasion wherein tumor cells extend beyond the tumor edge within the lung parenchyma. In lung adenocarcinoma (ADC), we investigated the (a) association between STAS and procedure-specific outcomes (sublobar resection and lobectomy), (b) effect of surgical margin/tumor diameter ratio in STAS-positive patients, and (c) potential utility of frozen section (FS) for detecting STAS intraoperatively. Methods : We investigated 1497 patients who underwent lobectomy (n=970) or sublobar resection (n=527) for T1N0M0 lung ADC, following propensity-score matching. Outcomes were analyzed using a competing-risks approach. The effect of margin/tumor ratio on recurrence pattern (locoregional and distant) was investigated in sublobar patients. Five pathologists evaluated the feasibility of intraoperatively identifying STAS using FS (sensitivity, specificity, interrater reliability). Results : On multivariable analysis following propensity-score matching (349 pairs/procedure), sublobar resection was significantly associated with recurrence (subhazard ratio, 2.84; P<0.001) and lung cancer–specific death (subhazard ratio, 2.63; P=0.021) in patients with STAS but not in those without STAS. Patients with STAS who underwent sublobar resection had a higher risk of locoregional recurrence regardless of margin/tumor ratio (margin/tumor ratio ≥1 vs. <1: 5-year cumulative incidence of recurrence [CIR], 16% and 25%); among patients without STAS, locoregional recurrences occurred in patients with margin/tumor ratio <1 (5-year CIR, 7%). Sensitivity and specificity for detecting STAS by FS were 71% and 92%, with substantial interrater reliability (Gwet’s AC1, 0.67). Conclusions : In T1 lung ADC patients with STAS, lobectomy was associated with better outcomes than sublobar resection. Pathologists can recognize STAS on FS.