Objective: Glycodelin is a 28 kDa glycoprotein, previously known as placental protein 14 (PP 14). Glycodelin displays immunosuppressive and contraceptive properties. It also suppresses the cytolytic capacity of human natural killer (NK) cells in vitro and inhibits binding of sperm cells to the zona pellucida (the outer membrane of the oocyte). Glycodelin is expressed in normal glandular epithelium of the endometrium as well as in endometrial, ovarian and cervical carcinoma cells. Glycodelin is also expressed in normal and malignant glandular cells outside the reproductive tract, like hidroadenoma, parabronchial glands, sweat glands and pancreatic cystadenoma. Recently, glycodelin was demonstrated to be expressed in normal and cancerous human breast tissue.
Materials and methods: Paraffin-embedded slides of carcinoma in situ (8 DCIS, 2 CLIS), invasive carcinomas without lymph node metastases (9 invasive duct carcinomas, 1 invasive lobular carcinoma) and invasive carcinomas (7 invasive duct carcinomas, 2 invasive lobular carcinomas, 1 mucinous carcinoma) with corresponding lymph node metastases were used. Immunohistochemical staining reaction was used to detect glycodelin expression in the different types of carcinoma in situ, in invasive carcinoma of the human breast and in metastatic carcinoma in axillary lymph nodes.
Results: Glycodelin expression was found in all cases of carcinoma in situ (10/10). In the group of invasive carcinoma of the breast (ductal and lobular carcinoma) without lymph node metastases, expression of glycodelin was demonstrated in 9 cases (9/10), of whom 3 cases showed a strong and 6 cases a mediate to weak expression of glycodelin. Only 1 case was negative. In the group of invasive breast cancer with axillary lymph node metastases, in 5 cases (4 ductal and 1 lobular carcinoma) there was no expression of glycodelin, either in the primary tumour tissue, or in the metastatic infiltration of the axillary lymph nodes (5/10). In only one case (invasive ductal carcinoma) was there a strong expression of glycodelin in the primary tumour and a weak expression in the metastasis in axillary lymph node. In 4 other cases (2 ductal, 1 lobular and 1 mucinous), there was a weak staining in primary breast cancer cells and no expression in the metastatic lymph node.
Conclusion: These results demonstrate that invasive breast carcinomas without axillary lymph node metastases (better prognosis) are more likely to express glycodelin. In contrast, the cases of breast cancer with metastatic infiltration of the axillary lymph nodes showed no (or weak) expression of glycodelin (worse prognosis). On the basis of these results, we speculate that glycodelin expression could be used as a prognostic marker for breast cancer. This has to be confirmed in larger studies.