Abstract P2-10-23: Lymphovascular Invasion (LVI) and Overall Survival in Node-negative and Node-positive Breast Cancer Patients: A Meta-analysis.

Abstract

Abstract Introduction: LVI is an important prognostic factor in patients with lymph node-negative invasive breast cancer. The prognostic value of LVI in lymph node-positive disease or in other subgroups remains unclear. Here we present a meta-analysis of studies assessing the impact of LVI on overall survival (OS) in different subgroups of breast cancer patients. Methods: A published data meta-analysis was conducted. Studies reporting hazard ratios (HR) for the association of LVI with OS in a multivariable model were included. Those not reporting HR or utilizing only univariable analyses were excluded. HR and 95% confidence intervals (CI) were extracted or computed and pooled using the DerSimonian and Laird random effects model. Subgroup analyses were conducted for the differential effect of lymph node involvement, estrogen receptor (ER) status, extent of LVI and decade in which the study was conducted (pre 1990, 1990–1999 and 2000 onwards). Results: Twenty studies comprising 40,417 patients were included in the analysis. There was marked heterogeneity in the effect size between studies (Cochran Q p < 0.001, I2=62%). When all studies were pooled, LVI was significantly associated with worse OS (HR:1.70 95% CI 1.49–1.95, p < 0.001). Among studies selecting patients by lymph node status, the association between LVI and OS was similar for lymph node positive and negative patients (HR:2.03 and 2.41 respectively, subgroup difference p = 0.56). There were no significant differences based on ER-status (subgroup difference p = 0.75) or decade of study (subgroup difference p = 0.21). Pooled assessment of the effect of extent of LVI was not possible as this parameter was not consistently reported. Conclusion: LVI is associated with similarly detrimental OS regardless of lymph-node or ER status. Improvements in adjuvant therapies over the past 20 years do not appear to have diluted the impact of LVI on OS. The marked heterogeneity in the effect size may result from differences in the extent of LVI. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-10-23.