Sublobar Resection Is Not Associated with Increased Risk of Recurrence in Stage I Non-Small Cell Lung Cancer with Lymphovascular Invasion

J. R. Brady¹, B. Walker², J. C. Zajac³, D. McCarthy⁴, J. Maloney⁵, M. DeCamp², A. L.. Axtell^6
1University of Wisconsin Clinics & Hospitals, Madison, Wisconsin ²University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin ³University of Wisconsin Hospitals and Clinics, Madison, Wisconsin ⁴University of Wisconsin, Madison, Wisconsin ⁵UW Hospital and Clinics, Madison, Wisconsin ⁶University of Wisconsin, Verona, Wisconsin

Purpose: Stage I lung cancer patients are routinely being treated with sublobar resection. However, it is debated whether patients with lymphovascular invasion (LVI), a known indicator of aggressive disease, derive similar benefits. Therefore, we analyzed the association between LVI and overall recurrence, specifically in patients who underwent sublobar versus lobar resection.

Methods: A retrospective cohort analysis was conducted on 555 adult patients who underwent a first-time pulmonary resection for non-small cell lung cancer (NSCLC) at a single academic institution between January 2016 and December 2022. Baseline clinical, operative, and pathologic characteristics were compared between patients who did and did not have LVI on final pathologic assessment. Overall survival and cumulative incidence of recurrence were compared between patients with and without LVI using the Kaplan-Meier method. Overall survival and cumulative incidence of recurrence were also compared in a predefined subgroup of stage I patients with and without STAS who underwent lobectomy versus sublobar resection (wedge resection or segmentectomy).

Results: Of 555 patients who underwent a pulmonary resection for lung cancer, 174 (31%) had tumors with LVI. There was no difference in LVI based on patient comorbidities or pulmonary function. Histologically, there was no significant difference is overall histological type, but patients with LVI were more likely to have solid and micropapillary predominant features, poorly differentiated grade (71% vs 39%, p= < 0.001), a larger tumor size (3.1cm vs 2.1cm, p= < 0.001), concurrent visceral pleural invasion (49% vs 23%, p= < 0.001), and a more advance pathologic stage (p < 0.001). Patients with LVI had significantly reduced overall survival (p < 0.009) in the entire cohort. However, in the subgroup with stage I disease, there was no difference in overall survival (p=0.067) based on LVI status. This association remained consistent when comparing stage I patients with LVI who underwent sublobar vs lobar resection (p=0.145) (Figure 1.) Patients with LVI had significantly increased cumulative incidence of recurrence compared to those without LVI (p= < 0.001), and this remained significant in the stage I subgroup (p=0.0002). However, the cumulative incidence of recurrence in stage 1 LVI-positive tumors did not differ based on whether the patient underwent lobar versus sublobar resection (p=0.622).

Conclusion: Lymphovascular invasion is associated with pulmonary adenocarcinoma with solid and micropapillary features. For stage I NSCLC, LVI is not associated with decreased overall survival, regardless of resection type. While the presence of LVI increases the overall risk of recurrence, there is no difference in recurrence risk with a sublobar resection.

Identify the source of the funding for this research project: None.