Evaluation of E-cadherin, Ki-67 and lymphatic vessel invasion in abdominal metastases of human breast cancer.

BACKGROUND

Abdominal metastasis is a rare finding in human breast cancer and is associated with a poor prognosis. Previous data suggest that mainly invasive lobular carcinomas tend to metastasize to the abdomen. The aim of the present study was to offer deeper insight into the biology of this rare kind of tumor spread.

MATERIALS AND METHODS

The expression of the cell adhesion protein E-cadherin, the cell proliferation marker Ki-67, as well as lymphatic vessel invasion (LVI), determined by staining with D2-40, were analyzed by immunohistochemistry in samples of primary breast cancer (n=12) and their associated abdominal metastases.

RESULTS

In nine cases the tumors and their abdominal metastases were E-cadherin-positive and biologically belonged to the invasive ductal subtype. In three E-cadherin-positive cases, abdominal metastasis was an earlier event compared to E-cadherin-negative cases (90 months versus 37 months). None of the primary tumors showed LVI after immunostaining with D2-40. Higher Ki-67 levels were found in the E-cadherin-positive primaries and metastases.

CONCLUSION

Most of the investigated tumors biologically belonged to the invasive ductal subtype. The findings of this analysis provided evidence that metastatic spread to the abdomen does not predominantly appear in lobular invasive carcinomas.