Background: This study assessed the prognostic effect of lymphatic and blood vessel invasion (LVI and BVI) on survival in a retrospective sample of 1408 patients with breast cancer.
Methods: Survival analysis was evaluated by univariate (Kaplan-Meier product limit method and log rank test) and multivariate (Cox model) analysis. Correlations among variables were studied by contingency tables and statistical significance was evaluated by chi-square test.
Results: Lymphatic vessel invasion was present in 34.2% of cases, and BVI in 4.2%. Lymphatic vessel invasion correlated with BVI (P < 0.0001), and both were correlated with metastatic axillary lymph nodes and increasing tumor size and grade; BVI was sporadic (only 10 cases) among lymph node negative patients. Although LVI was more frequent among premenopausal patients and those with ductal carcinomas, BVI was unrelated to menopausal status and tumor type. Lymphatic vessel invasion and BVI were associated with poor survival by univariate analysis (P < 0.0001). By multivariate analysis, relative risk of death was significantly increased when LVI was present both in the whole series as well as in the lymph node negative and lymph node positive subgroups; the prognostic role of LVI was independent of menopausal and lymph node status, tumor size, tumor grade, or adjuvant treatment. In the lymph node negative sample, LVI had strong prognostic power. In the lymph node positive sample, the prognostic role of LVI was also independent of the number of lymph nodes with metastases. Blood vessel invasion had no prognostic role in any subgroup.
Conclusion: The prevalence of BVI was particularly low in this study, and the question of its possible prognostic role for patients with breast cancer should be assessed with methods that amplify its detection. LVI is a strong prognostic factor for operable patients with breast cancer. In lymph node negative patients, LVI is a predictor of poor prognosis for those who are consequently candidates for adjuvant therapy. Similarly, in lymph node positive patients, LVI is a predictor for a high risk of death for those who are candidates for highly intensive adjuvant strategies.