Mutual Predictive Value of c-erbB-2 Overexpression and Various Prognostic Factors in Ductal Invasive Breast Carcinoma

Expression of c-myc, erbB-2, p53 and nm23-H1 gene product in benign and malignant breast lesions: coexpression and correlation with clinicopathologic parameters

The aims of this study were to assess the expression of protein products of c-myc, erbB-2, p53 and nm23-H1 gene in benign and malignant breast lesions, to estimate their possible coexpression and to correlate the results of immunohistochemical analysis with various clinicopathologic parameters. The method used was the immunohistochemical detection of the corresponding protein. Expression of c-myc protein was high in both malignant and benign lesions (95% and 100%). Expression of erbB-2 and mutated p53 proteins in malignant lesions was 27% and 34%. These proteins were present in benign lesions as well: 7.8% of benign lesions were positive for erbB-2 protein and 19.6% for p53 protein. The expression of nm23-H1 protein was similar in benign and malignant lesions: 47% and 54%. The coexpression of nm23-H1 and mutated p53 protein was found in 14 carcinomas (16.5%). We found a tendency of negative correlation between the expression of these two proteins. We also found a negative correlation between the size of breast carcinomas and the expression of nm23-H1, a higher proportion of nm23-H1-positive carcinomas in the group of erbB-2-negative, p53-negative carcinomas and a higher proportion of nm23-H1-positive carcinomas in the group of malignant lesions with negative axillary lymph nodes. Our results support the hypothesis that in women with breast cancer the expression of nm23-H1 gene may contribute to more favorable phenotype. We also showed that some changes found in malignant breast tumors such as the presence of mutated p53 protein and the expression of erbB-2 protein may be found in benign lesions as well.

c-erbB 2 Serum level as prognostic factor in hormonally treated advanced breast cancer patients

To investigate whether c-erbB 2 serum levels may be predictive of clinical response, progression-free and overall survival in postmenopausal women with advanced breast cancer hormonally treated, 265 patients enrolled in previous clinical trials were evaluated. C-erbB 2 serum levels were assessed before the start of treatment and in a subgroup of patients also at the first response evaluation. In addition, serum CA 15.3 levels were determined. The role of c-erbB 2 was investigated by means of multiple regression models in which both c-erbB 2 and CA 15.3 values were modelled as continuous variables together with other known prognostic factors. The failure probability tended to be higher in the presence of high c-erbB 2 levels, but the trend was not statistically significant; in contrast, significant results were obtained for progression-free survival (PFS,P <0.001) and overall survival (OS, P=0.014). The within-patient c-erbB 2 variation significantly predicted PFS (P=0.006) and OS (P=0.040). It is worth noting that c-erbB 2 and CA 15.3 baseline levels were significantly correlated and that the prognostic effect of c-erbB 2 tended to disappear in the presence of high CA 15.3 levels for PFS and OS.

Steroid receptor heterogeneity in relation to DNA index in breast cancer: a multiparameter flow cytometric approach on paraffin-embedded tumor samples

Steroid hormone (estrogen and progesterone) receptor (ER and PR) status at the time of breast carcinoma surgery is used as a marker for hormone dependency to guide adjuvant therapy. In a significant number of cases a discrepancy exists between the detected number of hormone receptors and the response to hormonal therapy. One of the explanations for this could be intratumoral heterogeneity. Our objective was to investigate the heterogeneity of steroid hormone receptor expression in breast cancer by using multiparameter flow cytometry (MP-FCM) on routinely processed formalin-fixed, paraffin-embedded tumors. A series of 232 routinely processed breast carcinomas were analyzed using a recently developed technique for the isolation of single cells from paraffin-embedded material. After dewaxing and rehydrating, 50-microm thick sections were heated for 2 hours at 80 degrees C in a citrate solution. Single-cell suspensions were prepared by a short pepsin digestion. The obtained single-cell suspensions were immunostained simultaneously for cytokeratin and ER or PR. Finally, DNA was stained using propidium iodide, after which the samples were analyzed on a flow cytometer. The fractions of ER- and PR-positive cells were determined in the total, as well as the G0 /G1 fraction of the diploid, and in case of nondiploid tumors, also in the G0 /G1 fraction of the aneuploid cell population. Of 232 cases, 88 (38%) were diploid, 38 (16%) were tetraploid, and 106 (46%) were aneuploid. In the diploid tumors the mean fraction of ER- and PR-positive cells was 81% and 76%, respectively. The ER- and PR-positive fractions in the total cytokeratin-positive fraction decreased significantly in the tetraploid (56% and 55%, respectively) and aneuploid tumors (both 47%, p < 0.0001). When analyzing the ER- and PR-positive fractions separately in the diploid and aneuploid cell populations of the nondiploid tumors, it became apparent that the ER and PR status in the diploid fraction of the tumor was significantly higher than in the aneuploid fraction (p < 0.0001). For the tetraploid tumors the mean ER- and PR-positive fractions were 79% and 76%, respectively, in the diploid fraction, and this decreased to 45% in the aneuploid cell subpopulation. In the aneuploid tumors this decrease was even more drastic: in the diploid cell population the ER- and PR-positive fractions were 66% and 62%, while this was 38% and 39% in the aneuploid population. These findings illustrate clearly the existence of a heterogeneous distribution of ER/PR expression in breast cancer, related to the loss of a diploid DNA index. Because of its objective quantification of subfractions within the same tumor, MP-FCM can be regarded as a superior method compared to more conventional techniques such as immunohistochemistry and biochemistry.

Significance of immunohistochemical c-ErbB-2 product localisation pattern for prognosis in human breast cancer

Breast cancer is an increasingly important cause of illness and death among women. In recent years several novel prognostic determinants of breast cancer have been identified, including c-ErbB-2. In this study, expression of c-ErbB-2 in breast carcinoma was correlated with axillary lymph node metastases and disease outcome. The expression of c-ErbB-2 oncoprotein was analysed in 315 tumor specimens of infiltrating ductal carcinoma of breast. They were categorized according to the modified Bloom and Richardson criteria into three histological grades. These patients also had axillary lymph nodes sampling. The expression of c-ErbB-2 oncoprotein was analysed immunohistochemically. Over expression of c-ErbB-2 were observed in 39.36% tumors. Axillary lymph node metastasis had significant correlation with intensified positivity of c-ErbB-2. C-ErbB-2 positive patients did show resistance to chemotherapy when compared for recurrence and distant metastases following surgery (p< 0.05). At a median follow-up of 48 months in c-ErbB-2 positive patients, the overall survival was 3.0 years and disease free survival was 2.5 years. c-ErbB-2 negative tumor patients showed a far better survival. In this group the overall survival was 4.44 years and the disease free survival was 3.78 years. These findings reinforce the view that c-ErbB-2 immunohistochemical detection is of help in detecting a subgroup of breast carcinoma patients who are at high risk. This may also be of particular relevance in decisions regarding adjuvant chemotherapy to these patients.