To investigate the clinicopathological significance of DEK overexpression in breast
cancers, a total of 196 cases, including 20 of normal tissues, 12 of intraductal
hyperplasia, 31 of
ductal carcinoma in situ (
DCIS) and 133 of invasive
ductal carcinoma of the breast, were selected from the Department of Pathology, Yanbian
Tumor Hospital for immunohistochemical staining of DEK,
estrogen (ER),
progesterone (PR) and Ki-67
proteins. In results, DEK
protein had higher positivity in
DCIS, compared with the adjacent normal breast tissues. Also, DEK
protein was strongly positive in invasive
ductal carcinoma of the breast on immunohistochemistry, which was significantly higher than normal breast tissues. However, only two (2/12) cases of intraductal
hyperplasia of the breast showed positive staining for DEK
protein. Additionally, DEK overexpression was significantly correlated with the increased proliferating index of Ki-67. For the histological grade, DEK positive rate was only 39.6% in G1 breast
cancers, but significantly higher in G2 (92.3%) and G3 (97.0%) cases (P<0.05). Also, a strongly positive rate of DEK was lower in Stage-0 (21.4%) and Stage-I (40.9%) compared with Stage-IIa (87.5%), Stage-IIb (89.7%) and Stage-IIIa (92.3%) (P<0.05). And DEK
protein showed higher expression level in < 3 years disease free survival breast
cancers than it did in ≥ 3 years disease free survival cases (P<0.05). However, no statistically difference was found among DEK expression,
lymph node metastasis, and ER and PR expressions. In conclusion, DEK overexpression appears to be associated with
breast cancer progression and DEK may potentially be used as a
breast cancer biomarker for the early diagnosis, prognostic evaluation and therapeutic target for
breast cancer.