Lymphovascular invasion is associated with reduced locoregional control and survival in women with node-negative breast cancer treated with mastectomy and systemic therapy.

Background: The impact of lymphovascular invasion (LVI) on postmastectomy locoregional relapse (LRR) and its use in guiding locoregional therapy in node-negative breast cancer are unclear. This study evaluates the association of LVI with relapse and survival in a cohort of women with early-stage breast cancer.

Study Design: The study cohort comprised 763 women with pT1-2, pN0 breast cancer referred from 1989 to 1999 and treated with mastectomy and adjuvant systemic therapy without radiotherapy. Kaplan-Meier LRR, distant relapse, and overall survival rates at 7 years were compared between patients with and without LVI. Cox regression analyses were performed to evaluate the prognostic significance of LVI for relapse and survival.

Results: Median followup was 7.0 years (range 0.34 to 14.9 years). LVI was present in 210 (27.5%) patients. In log-rank comparisons of Kaplan-Meier curves stratified by LVI status, LVI-positive disease was associated with significantly higher risks of LRR (p = 0.006), distant relapse (p = 0.04), and lower overall survival (p = 0.02). In the multivariable Cox regression analysis, LVI was significantly associated with LRR (relative risk [RR] = 2.32; 95% CI, 1.26-4.27; p = 0.007), distance relapse (RR = 1.53; 95% CI, 1.00-2.35; p = 0.05), and overall survival (RR = 1.46; 95% CI, 1.04-2.07; p = 0.03). In patients with one of the following characteristics: age younger than 50 years, premenopausal status, grade III histology, or estrogen receptor-negative disease, 7-year LRR risks increased threefold from 3% to 5% when LVI was absent, to 15% to 20% in the presence of LVI.

Conclusions: LVI is an adverse prognostic factor for relapse and survival in node-negative patients treated with mastectomy and systemic therapy. LVI, in combination with age older than 50 years, premenopausal status, grade III histology, or estrogen receptor-negative disease, identified patient subsets with 7-year LRR risks of approximately 15% to 20%. Prospective research is required to define the role of adjuvant radiotherapy in these patients.