Factors affecting lymphovascular invasion in node-positive breast cancer patients.

Abstract

24 Background: Lymphatic and/or vascular invasion (LVI) is not uniformly reported in breast cancer tumors, and may be absent even in LN+ patients. The purpose of this study was to define factors associated with (a) the non-reporting of LVI, and (b) the finding of no LVI in LN+ patients. Methods: Data from 400 LN+ patients from a cohort of patients in a prospective multicenter study were reviewed. Institutional and clinicopathologic factors correlating with the reporting and finding of LVI were assessed using non-parametric statistical analysis. Results: Of the 400 LN+ patients in this cohort, LVI was not reported in 98 (24.5%) patients. Of the remaining 302 patients, LVI was reported as negative in 147 (48.7%). LVI was more often reported in later years (84.9% in 2001-2004 vs. 67.9% in 1997-2000, p<0.001). The reporting of LVI did not vary significantly by region, teaching affiliation, community size, or the surgeon’s proportion of breast practice or number of cases. Further, reporting of LVI was not associated with surgery type, patient age, number of positive nodes, size of largest metastasis, nor extracapsular extension. LVI was, however, more frequently reported in larger tumors (median tumor size 2.0 cm vs. 1.8 cm, p=0.030). Despite the finding that LVI was more frequently reported in later years, the proportion of patients found to have LVI did not vary by year (53.3% in 2001-2004 vs. 49.3% in 1997-2000, p=0.565), region, teaching affiliation, community size, or surgeon practice. LVI positivity was associated with younger age (median age 53 vs. 60, p=0.001), larger tumors (median size 2.5 vs. 1.8 cm, p<0.001), more positive lymph nodes (median 2.5 vs. 1, p<0.001), more macrometastases (58.7% vs. 36.5%, p=0.002), and more extracapsular extension (70.3% vs. 46.0%, p=0.001). Conclusions: Reporting of LVI has improved in recent years, and while the rate of LVI positivity has not changed in LN+ patients, it remains associated with poor prognostic factors in this cohort. Therefore, reporting of LVI should be encouraged as a standard part of synoptic pathology reports for breast cancer patients, regardless of lymph node status.