Concurrent Spread Through Air Spaces in Dominant Tumors Impacts Prognosis in Synchronous Multiple Primary Lung Adenocarcinoma

This study investigates the prognostic impact of tumor spread through air spaces (STAS) in early-stage synchronous multiple primary lung adenocarcinoma (sMPLA) and its interaction with surgical strategies. Among 131 patients with cT1-3N0M0 sMPLA, STAS was detected in 52 percent, including 16 percent with STAS in both tumors (bi-STAS). Bi-STAS independently predicted significantly worse overall survival and recurrence-free survival compared to mono-STAS or no STAS. Patients with bi-STAS exhibited higher mortality and recurrence rates, regardless of whether they underwent lobectomy or sublobar resection, indicating limited benefit from more extensive surgery. Prognostic factors also included tumor size, pleural invasion, and lung diffusion capacity. These findings underscore the importance of comprehensive STAS evaluation in all dominant tumors for postoperative risk stratification in sMPLA.