The Presence of Extensive Lymphovascular Invasion is Associated With Higher Risks of Local-Regional Recurrence Compared With Usual Lymphovascular Invasion in Curatively Treated Breast Cancer Patients

Purpose: Several data sets have demonstrated a correlation between lymphovascular invasion (LVI) and locoregional recurrence (LRR). Whether the observation of "extensive LVI" is a further and incremental determinant of LRR risk is unknown. We describe clinical outcomes in women with invasive breast cancer stratified by (1) absence of LVI (neg), (2) LVI focal or suspicious (FS-LVI), (3) usual (nonextensive) LVI (LVI), and (4) extensive LVI (E-LVI).

Methods and materials: Between December 2009 and August 2021, 8837 patients with early-stage breast cancer were treated with curative intent and were evaluable. Clinical-pathologic details were abstracted by retrospective review. The description of LVI was abstracted from pathology reports. Recurrence and survival outcomes were compared based on the extent of LVI. A matched propensity score analysis compared outcomes between patients with LVI versus E-LVI.

Results: Of the 8837 patients studied, 5584 were negative, 461 had FS-LVI, 2315 had LVI, and 477 had E-LVI. Patients with E-LVI had an adverse risk profile compared with the other groups. The 5- and 10-year LRR cumulative incidence estimates in patients with E-LVI were 9.6% (95% CI, 7.1-13) and 13% (95% CI, 10-17), respectively, which were significantly higher than those observed in the usual LVI group (6.8% [5.7-7.9] and 10% [8.8-12], respectively). A statistically significant difference in LRR was demonstrated in univariable (HR, 1.4; 95% CI, 1.03-1.89; P = .029) and multivariable regression analysis (HR, 1.62; 95% CI, 1.15-2.27; P = .005) compared with nonextensive LVI. In an alternative approach, we performed a 2:1 propensity score matching analysis comparing patients with LVI to those with E-LVI. The hazard ratio for LRR (HR, 1.47; CI 1.02-2.14; P = .041) was suggestive of a higher risk associated with E-LVI.

Conclusions: Our work suggests that patients with E-LVI are at a higher risk for LRR than those with usual LVI. For patients who are borderline candidates for regional nodal irradiation or post-mastectomy radiation therapy, the finding of E-LVI might be decisive in favor of intensified treatment.