Purpose: Few studies evaluated the prognostic value of the presence of lymphovascular invasion (LVI) after neoadjuvant chemotherapy (NAC) for breast cancer (BC).
Methods: The association between LVI and survival was evaluated in a cohort of BC patients treated by NAC between 2002 and 2011. Five post-NAC prognostic scores (ypAJCC, RCB, CPS, CPS + EG and Neo-Bioscore) were evaluated and compared with or without the addition of LVI.
Results: Out of 1033 tumors, LVI was present on surgical specimens in 29.2% and absent in 70.8% of the cases. Post-NAC LVI was associated with impaired disease-free survival (DFS) (HR 2.54; 95% CI 1.96-3.31; P < 0.001), and the magnitude of this effect depended on BC subtype (Pinteraction = 0.003), (luminal BC: HR 1.83; P = 0.003; triple negative BC: HR 3.73; P < 0.001; HER2-positive BC: HR 6.21; P < 0.001). Post-NAC LVI was an independent predictor of local relapse, distant metastasis, and overall survival; and increased the accuracy of all five post-NAC prognostic scoring systems.
Conclusions: Post-NAC LVI is a strong independent prognostic factor that: (i) should be systematically reported in pathology reports; (ii) should be used as stratification factor after NAC to propose inclusion in second-line trials or adjuvant treatment; (iii) should be included in post-NAC scoring systems.
Keywords: Breast carcinoma; Lymphovascular invasion; Neoadjuvant chemotherapy; Prognostic scores.