Alvaro Ruibal

Zn-α2-glycoprotein levels in breast cancer cytosols and correlation with clinical, histological and biochemical parameters

Abstract Zn- α 2 -glycoprotein (Zn-α 2 -gp), a protein present at high levels in breast cyst fluid, has been measured in 104 breast tumour cytosols by using an immunoenzymatic assay. Concentrations of Zn-α 2 -gp ranged from 0 to 23.5 μg/mg of total soluble protein, with an average value of 2.4 μg/mg. There was no significant correlation between Zn-α 2 -gp and menopausal status, tumour size or lymph node involvement, or between this protein and biochemical parameters such as oestrogen receptor, cathepsin D or pS2 levels. However, there was a significant association between Zn-α 2 -gp and histological grade of tumours, with higher Zn-α 2 -gp levels in well-differentiated tumours (mean 4.6 μg/mg) than in moderately (1.8 μg/mg) or poorly (0.9 μg/mg) differentiated tumours. On the basis of these results, we propose that Zn-α 2 -gp may be considered as a biochemical marker of differentiation in breast cancer.

Histologic Grade and CD44 Are Independent Predictors of Axillary Lymph Node Invasion in Early (T1) Breast Cancer

Background: The detection rate of small, often subclinical breast cancers is increasing in affluent societies. Concomitantly, the demand for more conservative surgical approaches is also increasing among the women affected. Predictors of the absence of nodal invasion would spare many patients with early breast cancer the risks, costs and side effects of lymphadenectomy, and thus treatment with curative intent would be applied using really minimal surgery. Patients and Methods: We reviewed the records of 135 patients with unifocal invasive breast cancers, 2 cm or less in diameter, operated upon at ‘Fundación Tejerina-Centro de Patología de la Mama’, Madrid, Spain, between January 1993 and December 1997. Full clinical and pathological data were available for all of them, together with estrogen and progesterone receptor determinations, which had been routinely performed in 134 and 133 cases, respectively. Additionally, Ki67, c-erb-B2, p53, nm23, HSP27, HSP60 and CD44std expression was studied on archival, paraffin-embedded tumor material from these same patients by means of immunohistochemistry. Results: In the univariate analysis, only histologic grade 3 (p < 0.001), Ki67 expression in more than 10% of tumor cells (p = 0.005) and CD44std negativity (p = 0.004) were significantly associated with axillary node involvement. In multivariate analysis, histologic grade 3 and CD44std negativity retained statistical significance, and thus emerged as independent predictors of nodal invasion. The combination of both, furthermore, identified a subgroup in which the axillary nodes were invariably affected. Conclusion: Some pathological and molecular features of small breast cancers were able to predict nodal metastasis significantly. However, none, either alone nor combined, was able to exclude axillary node invasion completely.

Cathepsin D in breast secretions from women with breast cancer

A proteinase accumulated in breast secretions from women with breast cancer has been characterised. Inhibition of the proteolytic activity of breast secretions by pepstatin A showed that the main enzyme involved was an aspartyl proteinase. Determination of its cleavage specificity by SDS-PAGE and amino acid sequence analysis revealed that it was identical to that of cathepsin D, an aspartyl proteinase suggested to be involved in breast cancer development. The identity between both proteins was further confirmed by immunological analysis with monoclonal antibodies against cathepsin D. Quantification of cathepsin D in nipple fluids from 41 women with benign or malignant breast diseases and from 19 control women without breast pathology revealed the presence of variable amounts of this proteinase. The average concentration of cathepsin D in breast secretions from cancer-bearing breasts was 7.2 +/- 2.2 fmol micrograms of protein, which was significantly higher than those of nipple fluids from control women (2.9 +/- 0.6 fmol micrograms-1) (P = 0.04) or from patients with benign breast diseases (2.1 +/- 0.3 fmol micrograms-1) (P = 0.004). Though the number of cancer patients studied was small (n = 21), no correlations were found with cytosolic concentrations of cathepsin D or oestrogen receptors, neither with other parameters such as tumour size, histological grade, axillary node involvement or menopausal status.

Comparative Study of Carbohydrate Antigen 195 and Carcinoembryonic Antigen for the Diagnosis of Pancreatic Carcinoma

p < 0.001). Sensitivity was increased to 92.5% with the simultaneous use of the two antigens, but the difference was statistically significant only with CEA (p < 0.001). The specificity of CA195 calculated from all patients with benign diseases was lower than that of CEA (73.1% vs. 89.8%). However, using a cutoff value of 100 U/ml for CA195, the specificity of this antigen (82%) was higher than that of CEA. These results demonstrate that marked elevations of tumor antigen CA195 are relatively specific for pancreatic carcinoma, and that this antigen is superior to CEA for diagnosing pancreatic cancer by virtue of its higher sensitivity.

Quantification and molecular analysis of cathepsin D in breast cyst fluids

Cyst fluids from 55 premenopausal women with gross cystic breast disease were classified by K+/Na+ ratio: 19 with ratio over 1 (type I) and 36 with ratio less than 1 (type II). Immunoradiometric assay of cathepsin D in both types of cyst fluids revealed the presence of large amounts of this proteinase. The average concentration of cathepsin D in type I cyst fluids was 63.3 nmol/l, which was significantly higher than that corresponding to type II cyst fluids (35.1 nmol/l). Immunoprecipitation analysis of intracystic cathepsin D demonstrated that this protein was present as the 52 kD non-processed precursor form of the molecule. Since procathepsin D is a useful prognostic marker in breast carcinoma, we suggest that cyst fluid quantification of cathepsin D could aid to detect patients affecting of gross cystic disease with higher risk for developing breast cancer.