Desmoplastic (scirrhous) invasion and
lymph node metastasis are critical for the treatment and prognosis of invasive
ductal carcinoma of the breast. Despite being an anti-angiogenic therapeutic candidate, Thrombospondin-1 (TSP-1) promotes invasion and
metastasis of some
carcinomas. To clarify the effect of
TSP-1 on invasion and
metastasis, we obtained 101 invasive
ductal carcinomas of the breast with axillary lymph node resection. All
tumors were histologically divided into two categories,
carcinomas with, and those with non- /minimal desmoplastic component. Immunohistochemistry for
TSP-1 was performed on all primary
tumors and axillary lymph nodes with
tumor metastasis. Fifty-four (53.5%) of 101
tumors were recognized as positive for
TSP-1 in the cytoplasm of
tumor cells. Histological study showed that significantly more
cancers with desmoplastic components (46/69, 66.7%) manifested
TSP-1 expression than did
cancers with no- or minimal (less than 20%) desmoplasia (8/32, 25.0%; p<0.001). Axillary
lymph node metastasis was significantly higher in TSP-1-positive- (28/54, 51.9%) than TSP-1-negative
cancers (11/47, 23.4%; p<0.005). The present study indicates that
tumor cells in the desmoplastic component strongly expressed
TSP-1 in invasive
ductal carcinoma of the breast and
TSP-1 participates in invasion of these
tumors. Our findings also suggest that
TSP-1 promotes
lymph node metastasis and
TSP-1 potentially could be a predictive marker for
metastasis.