[246] Objective Assessment of Lymphatic and Blood Vascular Invasion in Breast Carcinoma: Findings from a Large Case Series with Long Term Follow up

RA Mohammed, SG Martin, AM Mahmmod, EC Paish, IO Ellis. School of Molecular Medical Sciences-University of Nottingham, Nottingham, United Kingdom; Faculty of Medicine-Assiut University, Assiut, Egypt

Background: Vascular invasion (VI), encompassing both lymphovascular (LVI) and blood vascular invasion (BVI) plays an important role in breast cancer disease progression and influences patient prognosis. In a previous study we found that LVI is the predominant type of VI with minimal contribution of BVI and that use of immnohistochemical identification using podoplanin increase the accuracy of detection. The aims of this study were (1) to assess the frequency and the extent of LVI and BVI in a well characterized group of 1000 LN negative breast cancers with known 20 year follow up (2) to assess prognostic power of the VI in early breast cancer.
Design: Representative paraffin-embedded tumour sections were stained with the lymphatic marker podoplanin and the vascular markers CD34&CD31 to detect LVI and BVI respectively. Stained vessels were counted in each section and the results were correlated with clinicopathological criteria and patient survival.
Results: VI was detected in 218 (22% specimens); 211/218 (97%) were LVI while BVI was detected only in 7/218 (3%). The lowest frequency of LVI was in tubular (5.6%) and mucinous (7.1%) carcinomas and was highest in invasive carcinoma of no special type (26%). LVIs were located in the peritumoural areas in 76% of the LVI-positive specimens; and were intratumoural in 24%. The frequency of involved lymphatic vessels ranged from 1 to 79. 167specimens (79%) had <5 LVIs, 23 (11%) had 6-10 LVIs and 22 (10%) had >10 LVIs. There was no significant difference between the frequency of LVI and development of recurrence or death from the disease. The presence of LVI was significantly associated with the development of metastasis, recurrence, worse disease free interval (DFI) and worse overall survival (OS). The 20-year OS rate was 85% in patients without LVI compared with 68% in patients with LVI. In multivariate analysis for OS and DFI; LVI retained significance (P <0.0001). LVI was able to stratify into different prognostic groups even in aggressive sub types such as basal-like breast cancer.
Conclusions: VI in breast cancer is predominantly of lymph vessels and is a powerful independent prognostic factor in lymph node negative breast cancer. The use of immunohistochemical staining with podoplanin increases accuracy of identification.
Category: Breast

Monday, March 9, 2009 9:30 AM

Poster Session I Stowell-Orbison/Autopsy Award # 39, Monday Morning