ABSTRACT
<p><b>OBJECTIVE</b>To study the expression of a glycoprotein of plant origin in normal, benign and malignant breast tissues.</p><p><b>METHODS</b>Expression of a plant glycoprotein was examined in 5 samples of normal breast tissues, 20 fibro-adenoma and 136 breast cancer by SABC immunohistochemical staining and the results were analyzed by SPSS statistics software.</p><p><b>RESULTS</b>No positive staining was detected in normal breast tissues (0/5). Weak staining was observed in 4 of 20 (20.0%) breast fibro-adenoma. Positive staining was demonstrated in 116 out of 136 (85.3%) breast cancer specimens. The differences were statistically significant. The expression of plant-associated human cancer antigen was related to pathological grade (P < 0.05), tissue invasiveness (P < 0.01) and recurrence (P < 0.05), but not to patients' age, tumor size and c-erbB-2 expression.</p><p><b>CONCLUSION</b>The plant glycoprotein studied may be a human cancer-associated antigen which might be a potential marker of breast cancer.</p>