Expression and prognostic significance of apolipoprotein D in breast cancer.
Apolipoprotein D (apo D) is a glycoprotein involved in the human plasma lipid transport system and present at large amounts in cyst fluid from women with gross cystic disease of the breast. Apo D expression in breast carcinomas was examined by immunoperoxidase staining of a series of 163 tumors. A total of 60 (36.8%) tumors were negative for apo D immunostaining, 28 (17.2%) carcinomas were weakly positive, 33 (20.2%) were moderately stained, whereas the remaining 42 (25.8%) tumors were strongly stained with the specific antibodies. No significant correlation was found between apo D content and tumor size, lymph node involvement, or biochemical parameters such as estrogen receptors, cathepsin D, or pS2 protein. However, the finding of a significant association between apo D and menopausal status of patients or differentiation grade of tumors, with apo D values being lower in tumors from premenopausal women or in poorly differentiated carcinomas, suggested a potential value of this glycoprotein as a prognostic factor in breast cancer. Preliminary analysis of relapse-free survival and overall survival in a subgroup of 152 women with a mean follow-up of 42 months confirmed that low apo D values were significantly associated to a shorter relapse-free survival and poorer survival. According to these data, we propose that apo D in combination with other well-established prognostic factors may contribute to more accurately identify subgroups of breast cancer patients with low or high risk for relapse and death.
Díez-Itza
I
I
Departamento de Biología Functional, Facultad de Medicina, Universidad de Oviedo, Spain.
Vizoso
F
F
Merino
A M
AM
Sánchez
L M
LM
Tolivia
J
J
Fernández
J
J
Ruibal
A
A
López-Otín
C
C
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001053:Apolipoproteins / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D053399:Apolipoproteins D; D014408:Biomarkers, Tumor; D001943:Breast Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D002277:Carcinoma / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015151:Immunoblotting; D007124:Immunoenzyme Techniques; D008875:Middle Aged; D011379:Prognosis
D001053:Apolipoproteins; D053399:Apolipoproteins D; D014408:Biomarkers, Tumor