c-erbB-2 oncoprotein expression in primary and advanced breast cancer

ERBB2 oncogene in human breast cancer and its clinical significance

We reveiwed the relationships between ERBB2 amplification and/or overexpression in human breast cancer and the clinicopathological parameters described in the literature (97 studies involving 22,616 patients) in order to draw conclusions regarding its clinical interest. The mean of ERBB2 positivity (26%, ranging from 5 to 55%) is not dependent on the method used to evaluate ERBB2 amplification or overexpression. Despite the discrepancies observed between the different studies, several associations between ERBB2 positivity and the classical clinicopathological parameters were noted. There are clear relationships between ERBB2 positivity and the lack of steroid receptors, the histological subtypes of mammary tumours (ductal invasive and in situ), worse histological and nuclear grades, aneuploidy and high rate of proliferation. In univariate analyses, ERBB2 is strongly associated with poor prognosis. All these data indicate that ERBB2 is a marker of aggressiveness of the tumour. However, ERBB2 does not retain a clinical prognostic significance in multivariate analyses, since it is associated with several strong prognostic parameters. When considering the prognostic value of ERBB2 in relation to treatment, a significantly worse survival of the treated patients is noted in ERBB2 positive patients. This suggest that ERBB2 could be a marker of reduced response to chemotherapy and hormonal treatment. With respect to the tumour response to treatment, the results, provided as yet by pilot studies, remain controversial and further investigations are necessary to evaluate the predictive value of ERBB2. Finally, new therapeutic approaches targeting the cells overexpressing ERBB2 have been developed.

Potential prognostic value of C-erbB-2 expression in medulloblastomas in very young children

PURPOSE

The expression of the c-erbB-2 oncogene was studied in childhood medulloblastoma to evaluate its prognostic value, which has been claimed previously.

PATIENTS AND METHODS

Tumor material from 45 patients < 15 years old at diagnosis was studied using 3 monoclonal antibodies against the internal and external domains of the c-erbB-2 oncogene product.

RESULTS

Six of the 45 (13%) tumor specimens were found to be positive. C-erbB-2 expression was found more often in patients < 3 years old at diagnosis (4 of 15 patients, 27%) than in older patients (2 of 30, 6.6%). During the follow-up period (5.8 +/- 2.8 years) all patients with c-erbB-2 expression died of disease (after 1.2 +/- 0.7 years). Kaplan-Meier estimation revealed a highly significant correlation of c-erbB-2 expression and survival (p = 0.002). A further study of the expression of synaptophysin and the glial fibrillary acidic protein (GFAP) in the 45 tumors revealed a negative correlation of the expression of c-erbB-2 and these proteins.

CONCLUSION

C-erbB-2, which may be predominantly expressed by less differentiated tumors, was found to delineate a poorer prognostic subgroup, especially when diagnosed in patients < 3 years old.

c-erbB-3 protein expression in ductal carcinoma in situ of the breast

c-erbB-3, A recently identified member of the type I tyrosine kinase receptor family, has been shown to be overexpressed in invasive ductal carcinoma of breast. In this study, expression of the c-erbB-3 protein was examined in 57 cases of pure ductal carcinoma in situ of the breast (DCIS) by immuno-cytochemical methods. Staining was either absent (17 cases), present at levels equivalent to that found in adjacent normal tissue (20) or greater than in normal tissue (20). In most cases the pattern of staining was cytoplasmic, but in 4 cases with the most intense reaction there was also focal membrane staining. In the same series of cases, c-erbB-2 protein had previously been shown to be overexpressed in 28 of 57 cases, c-erbB-2 overexpression was correlated with normal level of c-erbB-3, and lack of c-erbB-2 expression was correlated with c-erbB-3 overexpression.

The pathological and biological nature of screen-detected breast carcinomas: a morphological and immunohistochemical study

Traditional and immunohistochemical markers of prognosis were examined in 455 mammary carcinomas derived from breast cancer screening and compared with those of 277 carcinomas presenting symptomatically over the same period. Tumours detected by population screening under the U.K. National Health Service Programme do not differ from those detected by other screening projects, but compared with symptomatic cancers, screen-detected cancers are more likely to be in situ and if invasive, to be smaller, of lower grade, and to have invaded vessels, perineural spaces, and lymph nodes less frequently. Tubular and cribriform types are more often represented in screened patients. Immunohistochemical markers which have been proposed as being related to likely tumour behaviour (epidermal growth factor receptor, c-erbB-2 protein, oestrogen and progesterone receptors, cathepsin D, p53, and retinoblastoma protein) do not distinguish screen-detected from 'clinical' cancers. It is concluded that cancers diagnosed at screening do not differ biologically from those presenting clinically, but are the same lesions detected at an earlier stage of their natural history.

Influence of circulating c-erbB-2 serum protein on response to adjuvant chemotherapy in node-positive breast cancer patients

This retrospective case control study investigated the therametric value of the circulating c-erbB-2 gene product (Her-2, NEU) as (1) an eligibility criterion for high doses of chemotherapy and (2) response to standard adjuvant chemotherapy in node-positive breast cancer patients. Preoperative c-erbB-2 levels were measured in 211 locally advanced (> 3 nodes positive), pre- and perimenopausal breast cancer patients to determine if circulating levels of the gene product can assist in the determination of appropriate therapeutic options. 152 of 211 breast cancer patients received post-operatively a combination chemotherapy including the anthracycline analog mitoxantrone, while 59 patients were treated with conventional CMF therapy. Using 120 fmol/ml as a cut-off level, elevated c-erbB-2 values were found in 26 (12.3%) patients with locally advanced breast cancer. In univariate analysis significant survival differences were detected when c-erbB-2 'positive' patients were compared with c-erbB-2 'negative' patients. However, no significant survival differences were detected, when c-erbB-2 'positive' patients were compared according to regimen of adjuvant treatment. In multivariate analysis c-erbB-2 was an independent prognostic factor for predicting disease-free survival, but not for overall survival. High levels of c-erbB-2 were associated with low estrogen and progesterone receptor concentrations of the tumor cytosol. There was no correlation between elevated c-erbB-2 values and age, tumor size or degree of nodal involvement. c-erbB-2 was a better predictor of risk of recurrence than extent of nodal involvement or hormone receptor status.

Amplification in tumors and benign tissue of breast cancer patients

Inappropriate expression of the c-erb B2 gene has been associated with aggressive tumor behavior in breast cancer. In this study the c-erb B2 amplification was investigated both in the tumors and benign breast tissue of the patients by competitive PCR. The technique combines the sensitivity and speed of PCR with coamplification of a single copy reference gene to achieve quantitative results. Gene copy numbers in excess of 3 copies were observed in tumors of 7 patients but not in the normal tissue samples. We conclude that the increase in the gene copy numbers is a result of the tumorigenic changes occurring in the cancer cell.

Prognostic significance of serum c-erbB-2 protein in breast cancer patients

The tissue expression of c-erbB-2 protein in breast cancer is a marker of poor prognosis in a number of studies. More recently it has also been suggested that c-erbB-2 expression may predict response to systemic therapy in patients with advanced breast cancer. The measurement of c-erbB-2 protein in the serum of breast cancer patients has now been reported, but the significance of this finding is not clear. In this study an ELISA assay was used to measure c-erbB-2 in the sera of 23 normal controls, 46 benign breast disease patients, and 119 breast cancer patients. Elevated serum c-erbB-2 protein levels were detected in 13% (3/23) of normal controls, 15% (7/46) of benign disease patients, 15% (7/46) of Stage I/II patients, 26% (9/35) of Stage III patients, and 21% (8/38) of Stage IV patients. The tissue expression of the c-erbB-2 protein showed no association with detection of the serum c-erbB-2 protein (p = 0.31). In the 67 Stage III and IV patients who had assessable disease the presence of the c-erbB-2 protein in the serum bore no relationship to response to hormonal therapy (p = 0.71). Serum detection of the c-erbB-2 protein in Stage I/II patients predicted for a worsening of both survival outcome (p = 0.002) and disease free interval (p = 0.002). A worse outcome was also seen for the Stage III patients (p = 0.04) and Stage IV patients, although the latter did not reach statistical significance (p = 0.27). This study found that the presence of c-erbB-2 in the serum of breast cancer patients was of prognostic significance for all stages of disease.

The predictive power of semiquantitative immunohistochemical assessment of p53 and c-erb B-2 in lymph node-negative breast cancer

A series of 107 lymph node-negative (LNN) breast cancers was stained immunohistochemically with a combination of p53 and c-erb B-2. The immunohistochemical results were semiquantitated using a previously described system by Allred et al. p53 immunopositive cases were further screened for DNA mutations by the polymerase chain reaction-single-strand conformation polymorphism method (PCR-SSCP). Three representative cases showing mobility shifts were directly sequenced. One hundred of 103 invasive carcinomas were of no special type (infiltrating ductal carcinomas not otherwise specified). The three special type carcinomas included a tubular carcinoma, a classic infiltrating lobular carcinoma, and a mucinous carcinoma. Twenty-six patients (25.2%) had grade I carcinomas, and 77 patients (75%) had grade 2 or 3 carcinomas. There were four cases composed predominantly of ductal carcinoma in situ (DCIS) with foci of microinvasion. Twenty-seven of 107 patients (25%) died of disease. All those who died had grade 2 or 3 tumors. Univariate analysis showed that p53 and c-erb B-2 positivity (score > 6) were associated with a decreased overall survival (OS) (P = .0012 and P = .010, respectively), and a decreased disease-free survival (DFS) (P = .0009 and P = .027, respectively). The multivariate model selected these two variables as the best predictors of both OS and DFS (all P = or < .01). These results suggest that semiquantitative immunohistochemical analysis of p53 and c-erb B-2 provides prognostic information in LNN disease.

C-erbB-3 in human breast carcinoma: expression and relation to prognosis and established prognostic indicators

A series of 346 patients with primary operable breast cancer and a series of 145 patients with advanced breast cancer were investigated for c-erbB-3 protein expression using the monoclonal antibody RTJ1. Formalin-fixed, paraffin-embedded tumour samples were stained using a standard immunochemical method and staining was assessed on a four-point scale. The study aimed to observe the expression of the c-erbB-3 protein and investigate any relationship between expression and established prognostic indicators and prognosis. In both the primary and advanced series breast tumour tissue was found to stain heterogeneously for c-erbB-3. The staining was observed to be predominantly cytoplasmic and the majority of tumours exhibited moderate positivity. However, 15% and 35% of cases in the primary operable and advanced series respectively displayed strong positive staining. No significant difference was found between the staining in the primary and advanced series. In the primary operable breast cancers, no significant associations were demonstrated with overall survival, disease-free interval, regional recurrence, the presence of distant metastases, age, menopausal status, oestrogen receptor status, histological grade, lymph node stage, vascular invasion and c-erbB-2 protein expression. However, a significant association was seen between the degree of c-erbB-3 immunoreactivity and both tumour size (P < 0.01) and tumour type prognostic group (P = 0.05). No overall association with local recurrence was seen when the four groups of c-erbB-3 expression were analysed (P = 0.12), but when those tumours showing no or weak staining were compared with those showing moderate and strong immunoreactivity it was seen that the latter were significantly more likely to develop local recurrence (P = 0.03). In the series of patients with advanced disease, no significant associations were demonstrated with survival, UICC criteria, age, menopausal status, oestrogen receptor status, histological grade, c-erbB-2 status or the presence of vascular invasion. In conclusion this study found variable expression of c-erbB-3 protein in human breast carcinoma and an association with some recognised prognostic factors in those patients with primary operable breast carcinoma. It seems, however, unlikely that c-erbB-3 protein expression will emerge as a powerful enough prognostic factor to be of value in clinical practice.

Prognostic significance of c-erbB-2 oncogene in axillary node-negative breast cancer

BACKGROUND

With the advent of screening mammography more breast cancer will be detected at an earlier stage, apparently confined to the breast with no nodal involvement. However, 30% of these will recur due to micrometastases present at the time of diagnosis. Chemotherapy and tamoxifen have been shown to improve disease-free survival in axillary node-negative patients but not overall survival. In the search for a useful predictor of breast cancer recurrence the relationship between c-erbB-2 expression and recurrence and survival was examined.

METHODS

Eighty-eight axillary node-negative breast cancer patients were followed up for at least 5 years.

RESULTS

There was a significant relationship between c-erbB-2 expression and both tumour recurrence (P<0.001) and poorer survival (P=0.003). In a Cox multiple regression analysis, c-erbB-2 staining remained the only significant prognostic variable for recurrence (P=0.002) and survival (P=0.032). Tumour recurrence in c-erbB-2-positive cases tended to occur early in the course of follow up and was associated with poorer survival.

CONCLUSION

C-erbB-2 was found to be a useful prognostic indicator for early recurrence and poorer survival in axillary node-negative breast cancer patients.

INT2 and ERBB2 amplification and ERBB2 expression in breast tumors from patients with different outcomes

The relationships of INT2 and ERBB2 amplification and of ERBB2 overexpression in primary breast tumors to prognostic factors, recurrence, and survival have generated considerable controversy. The rationale for this study is that long-term, recurrence-free survival is a more direct criterion for testing the validity of a tumor marker than correlation either with prognostic factors or with short-term recurrence and survival. We examined the association of recurrence with INT2 and ERBB2 amplification and ERBB2 expression by comparing primary breast tumors from patients surviving without recurrence for > or = 8.5 years after diagnosis, the LTS group, to tumors from patients recurring within two years, the RR group. The RR (N = 63) and LTS (N = 61) samples were coded and examined for amplification by Southern blotting and for expression by immunohistochemistry. Comparison between the RR and LTS groups demonstrated that INT2 amplification was associated with a significantly (P = 0.018) higher (5.6-fold) risk of recurrence, an association that remained significant after controlling for lymph node (LN), tumor size (TS), and histograde (HG) status. ERBB2 amplification and expression were not associated with a higher recurrence risk. Survival analyses within the RR group, however, demonstrated significantly shorter survival time among cases with than without ERBB2 amplification (P = 0.018, median survival 16 vs 25 months), or ERBB2 expression (P = 0.019, median survival 15 vs 25 months), but not INT2 amplification. Univariate Cox proportional hazards regression models also demonstrated significantly shorter survival among cases with ERBB2 amplification (P = 0.016) or expression (P = 0.049), that remained significant in multivariate analyses (P = 0.022) for ERBB2 amplification. These results indicate a significant positive association between INT2 amplification and risk for tumor recurrence in the RR as compared to the LTS group. The relationship of ERBB2 amplification or overexpression to patient outcome is more complex. ERBB2 amplification and expression have a significant relationship with shorter survival among patients recurrent within two years, but their occurrence in tumors from women surviving without recurrence for > or = 8.5 years suggests that ERBB2 status is not predictive of shorter survival for all breast cancers.

Use of a polyclonal antibody for the determination of the prognostic value of c-erbB-2 protein over-expression in human breast cancer

A rabbit-specific polyclonal antibody was obtained raised to a synthetic peptide corresponding to the 1238-1255 C-terminal predicted sequence of the c-erbB-2 protein. This antibody was used in an immunohistochemical procedure to detect the c-erbB-2 protein on a series of 88 paraffin-embedded human breast carcinomas. In 14/88 cases (16%) the c-erbB-2 protein was found to be overexpressed (immunohistochemical score > 1) with a good concordance with the previously determined mRNA level (79/88 cases: 90%). Prognostic significance of c-erbB-2 protein overexpression as detected by immunohistochemistry was tested by the log-rank test. The relative risk of relapse is higher for patients with an immunohistochemical score > 1 (p = 0.00002). In a multivariate analysis of the c-erbB-2 immunohistochemical score was the only powerful parameter (p < 1 x 10(-3). In conclusion, this antibody seems to be a valuable tool in estimating the c-erbB-2 protein regarded in our series as a parameter able to identify a subgroup of operable breast cancer patients with a high risk of relapse.

Expression of ras p21, p53 and c-erbB-2 in advanced breast cancer and response to first line hormonal therapy

Several oncogenes and tumour-suppressor genes have been identified that may have an important role in the development of human breast carcinoma. Furthermore, some of these gene alterations may be linked to the development of invasion and subsequent metastasis. Alterations in the expression of ras p21, p53 and c-erbB-2 have all been linked to tumours with rapid cellular proliferation, but the evidence that they are of prognostic importance in patients with breast cancer is conflicting. This study explores the relationship between expression of these oncoproteins and clinical outcome in 92 patients with either locally advanced or metastatic breast cancer treated with primary endocrine therapy. Specimens of the primary carcinoma were available for analysis of hormone receptor, Ki67 labelling index, epidermal growth factor receptor (EGFR), c-erbB-2, p53 and ras p21. Clinical response was measured according to UICC criteria after 6 months of treatment and all patients were followed for time to progression and overall survival. As shown previously, oestrogen receptor (ER) negativity, high Ki67 labelling index and EGFR overexpression were associated with a shorter time to progression and overall survival. However, no statistically significant relationship existed between expression of ras p21, p53 or c-erbB-2 and response to treatment, time to progression or overall survival. We conclude that staining for these three oncoproteins has no role in therapeutic decision-making in patients with advanced breast cancer. The negative finding implies that while abnormal expression of these genes may have an important role in the development of breast cancer, the variations in growth characteristics of advanced breast cancer may be influenced by other factors.

A flow cytometric study of c-erbB-3 expression in breast cancer

In order to assess the specificity of biotinylated anti-c-erbB-3 antibody, screening was performed on a series of tumour cell lines and lymphocytes. Staining was found to be consistent, with good reproducibility. Twenty-nine consecutive breast cancer samples were obtained from women treated with tamoxifen and undergoing elective mastectomy. Twenty-eight invasive ductal carcinomas and 1 DCIS were stained for c-erbB-3 expression: 2 were grade I (Bloom and Richardson), 15 grade II, and 11 grade III tumours, 1 being unclassified; 16 were axillary node positive and 10 node negative; in 2 cases no nodes were sampled. Tumours examined by flow cytometry were stained with cytokeratin FITC antibody and the cytokeratin-positive population gated. Using Mann-Whitney analysis no association was seen between c-erbB-3 expression and Bloom and Richardson grade or axillary node status. In the tumour samples c-erbB-3 expression was found to show as association with EGF-R (P = 0.021 r2 = 0.16), PgR (P = 0.02, r2 = 0.16), c-myc (P < 0.0001, r2 = 0.5), c-jun (P = 0.001, r2 = 0.4) and c-fos (P = 0.001, r2 = 0.5) but not with c-erbB-2 (P = 0.2, r2 = 0.06), ER (P = 0.4, r2 = 0.02) or p53 1801 (P = 0.05, r2 = 0.2). Expression of c-erbB-3 may not be an independent marker of prognosis, but it is associated with other markers of poor prognosis and early cellular events linked with aberrant growth and differentiation.

Prognosis of breast cancer: evidence for interaction between c-erbB-2 overexpression and number of involved axillary lymph nodes

The prognostic significance of c-erbB-2 oncogene amplification or overexpression in relation to axillary lymph node metastasis is controversial. We investigated this question in 159 cases of operable breast cancer: 56 patients with node negative disease and 103 patients with pathological involvement of axillary lymph nodes. c-erbB-2 overexpression was assessed by immunohistochemistry using a polyclonal antibody raised against a synthetic peptide fragment of the oncoprotein. The overall incidence of c-erbB-2 overexpression was 35%. c-erbB-2 overexpression was significantly related to survival when all patients were considered (P = 0.0124), and also for patients with positive axillary lymph nodes (P = 0.0026). c-erbB-2 overexpression had no influence on survival of node negative patients (P = 0.7972). A multivariate survival analysis using the Cox proportional hazard model revealed that number of involved lymph nodes, c-erbB-2 overexpression, ER status, and tumour size were independently related to prognosis (P = 0.0000, 0.0012, 0.0112, and 0.0204, respectively). When an interaction term was introduced in the Cox model between c-erbB-2 overexpression and number of involved axillary lymph nodes, a statistically highly significant interaction between these two factors was observed (P = 0.0002), suggesting that the expression of prognostic power of c-erbB-2 overactivity is related to the number of involved axillary lymph nodes. The 159 patients were then subdivided into three groups: node negative (-ve) (56); 1-6 node positive (+ve) (55); and > or = 7 node +ve (48). This cutoff criterion gave the most numerically equitable distribution of the 159 patients into three groups. The relative risk of death increased stepwise from 0.86 (95% CI 0.26-2.78) for node negative patients, to 1.95 (95% CI 0.82-4.63) for 1-6 node positive patients, to 2.23 (95% CI 1.15-4.35) for > 7 node positive patients. Our results suggest that the prognostic influence of c-erbB-2 overexpression increases arithmatically with increasing number of involved axillary lymph nodes.

The prognostic value of c-erbB2 in primary breast carcinomas: a study on 942 cases

To assess the practical prognostic value of c-erbB2, we performed a study on 942 invasive ductal carcinomas treated with primary surgery between 1980 and 1986 in our center. We evaluated its expression by immunohistochemistry in paraffin-embedded tissue using a polyclonal antipeptide antibody. Of 942 tumors, 229 (24%) showed a positive membrane staining. We observed a significant association between c-erbB2 and Scarff-Bloom-Richardson grading (p < 0.0001) and a negative correlation between c-erbB2 and both estrogen and progesterone receptors (p < 0.0001). In our analysis, with respect to overall survival (OS), relapse-free survival (RFS), and metastasis-free survival (MFS), c-erbB2 was statistically significant (p < or = 0.0001) for the whole group and the node-positive subgroup. In multivariate analysis, c-erbB2 appeared to be an independent variable for RFS and MFS in the node-negative group. However, in our hands, c-erbB2 had a poor prognostic value in comparison with the classical prognostic variables such as histological grade, nodal status (N), hormonal receptor status (estrogen and progesterone receptors), and tumor size, and it did not supersede the classical parameters.

The relationship between flow-cytometric and immunohistochemically detected c-erbB-2 expression, grade and DNA ploidy in breast cancer

Quantification of c-erbB-2 and its relationship with other prognostic markers using flow cytometry has been examined. In this study a level for c-erbB-2 expression above which tumours are classified as positive by flow cytometry has been determined by employment of positive cut-off threshold levels. c-erbB-2 expression by both flow cytometry and immunohistochemistry was studied using the monoclonal antibody NCL-CBII. The relationship of c-erbB-2 quantification by flow cytometry was then compared with ploidy, axillary node status, tumour size and grade. Increased c-erbB-2 expression was seen using flow cytometry. Correlation between immunohistochemistry and flow-cytometry methods just failed to reach significance (P = 0.06). Immunohistochemistry revealed a significant relationship between c-erbB-2 expression and aneuploidy (P = 0.04). Cytokeratin-positive cells from 110 samples obtained from patients with breast cancer were assayed for DNA content and c-erbB-2 expression by flow cytometry. No correlation was seen between these parameters upon application of Mann Whitney analysis. However, examination of fluorescence thresholds showed a positive correlation between grade and c-erbB-2 expression at a level of more than 3200 molecules (P < or = 0.03). At the level of 3600 molecules significance was increased (P = 0.004). These levels equated with between 15% and 19% of the samples being classified as c-erbB-2-positive. Application of these cut-off points showed no correlation between c-erbB-2 expression and ploidy, tumour size or axillary node status. Comparison of ploidy and grade showed a significant association (P = 0.0015), increased grade correlating with aneuploidy.

Ductal carcinoma in situ: assessment of necrosis and nuclear morphology and their association with biological markers

One hundred and five cases of pure ductal carcinoma in situ (DCIS) seen in the Guy's Hospital breast unit between 1975 and 1991 were reviewed. The presence and extent of necrosis and the degree of cytonuclear differentiation were assessed and the expression of p53 protein, cerbB2 protein, progesterone receptor, and a proliferation antigen KiS1, all factors reported to be of prognostic significance in invasive ductal carcinoma, was evaluated using immunohistochemical methods. A strong correlation was seen between the presence and extent of necrosis and the degree of cytonuclear differentiation and between both these morphological criteria and the biological markers as well as between the individual markers. The presence of extensive necrosis was associated with lack of cytonuclear differentiation and both were associated with a high proliferation rate, the presence of cerbB2 and p53 protein, and the absence of progesterone receptors. In cases with little or no necrosis, there was good nuclear differentiation and a strong correlation with the presence of progesterone receptor, absence of cerbB2 and p53 protein, and a low rate of proliferation.

The c-erbB-2 proto-oncogene as a prognostic and predictive marker in breast cancer: a paradigm for the development of other macromolecular markers--a review

Seven years after the initial studies of the prognostic value of the proto-oncogene c-erbB-2 in breast cancer, its role is still being defined. The interpretation of studies on the use of this gene and its protein product in prognostic and predictive tests for breast cancer is complicated by multiple methodologies and the inherent difficulties in the studies. The work has moved beyond the stage at which small studies with short follow-up (useful for hypothesis generation) are of value, to the stage in which large studies with sufficient statistical power to find significant correlations are central. These larger studies do not lend support for the use of c-erbB-2 in the evaluation of axillary-node-negative patients, the group of breast cancer patients for whom refinement of prognostic estimates is now most important. There are, however, hints that c-erbB-2 may have value in predicting response to certain treatments, though the studies so far are too few, often too small and too conflicting to reliably confirm this.

The neu-protein and breast cancer

The neu-protein is overexpressed in about 20% of invasive duct cell carcinomas of the breast. The only reliable sign for neu-overexpression by immunohistochemistry is membrane staining. Its overexpression is correlated with decreased overall survival and disease free survival due to increased metastatic activity of neu-overexpressing tumour cells. This increased metastatic potential is a consequence of the motility enhancing activity of the neu-protein, which is exclusively expressed on pseudopodia, and to a lesser extent of its growth stimulating effect. From a clinical point of view, the assessment of neu-overexpression in breast cancer might become a useful tool in the future treatment of patients by chemotherapy, since patients whose tumour shows neu-overexpression benefit from higher doses of chemotherapy. The molecule plays a key role in the pathogenesis of Paget's disease of the breast. A chemotactic factor which is secreted by epidermal keratinocytes attracts the Paget cells to spread into the epidermis and acts via the neu-protein. In ductal carcinoma in situ, the combination of neu-overexpression and large cell type is highly correlated with extent of disease and therefore neu-overexpression might be a predictive marker for recurrence of disease after tumour resection.

Prognostic significance of the c-erbB-2 oncogene product in childhood medulloblastoma

The expression and prognostic significance of the c-erbB-2 oncogene product was studied in 55 cases of childhood medulloblastoma. Forty-six of the 55 tumours (83.6%) expressed the c-erbB-2 product. The percentage of tumour cells expressing the c-erbB-2 product proved to be a significant indicator of patient outcome when analysed as both a categorical and a continuous variable. As a categorical variable, patients with more than 50% positive tumour cells had a significantly worse survival, with only 10% alive at 10 years vs 48% for those with less than 50% positive tumour cells (log rank P = 0.0049). To demonstrate that this observed prognostic significance was both independent and not a result of 'data-driven' categorisation, it was also entered into the Cox model as a continuous variable. Prognostic significance was retained in P = 0.038.

Prognostic value of proliferating cell nuclear antigen and c-erbB-2 compared with conventional histopathological factors in breast cancer

Expression of proliferating cell nuclear antigen (PCNA) and c-erbB-2 oncoprotein has been assessed in 471 women with breast cancer to evaluate their prognostic value as compared to conventional histopathological factors. In univariate analysis, high PCNA expression (> or = 20%) predicted a significantly worse survival in lymph-node-negative tumors (univariate P = 0.031). However, the effect disappeared in multivariate analysis and the histological grade remained the only independent factor for this group. Despite its close correlation to histological grade (P < 0.001), PCNA expression discriminated subsets with different survival within the heterogeneous group of moderately differentiated tumors (univariate P = 0.073, multivariate P = 0.075). PCNA expression was not found to be a significant prognostic factor in lymph-node-positive tumors, thus it was of limited value for breast cancer patients as a whole. c-erbB-2 protein overexpression was associated with a worse survival (univariate P = 0.019, multivariate P = 0.057) for the entire group of patients. The effect was mainly attributed to the significance of c-erbB-2 as an independent factor in lymph-node-positive (up to three nodes, multivariate P = 0.04; four or more nodes: multivariate P = 0.017) and large tumors (> 2 cm: multivariate P = 0.002). c-erbB-2 was without significance in lymph-node-negative patients. Though both factors might amplify the prognostic information for distinct patient subsets they do not achieve the strong prognostic value of conventional histopathological features in breast cancer.

Detection of c-erbB-2 related protein in sera from breast cancer patients. Relationship to ERBB2 gene amplification and c-erbB-2 protein overexpression in tumour

The level of a c-erbB-2 related protein was determined in sera from 168 breast carcinoma patients, 12 females with benign breast disease, and 66 female controls using an ELISA (enzyme linked immunosorbent assay) kit. Elevated c-erbB-2 related protein level was detected in one of 13 preoperative sera (8%), two of 62 postoperative sera from patients without recurrent disease (3%), and 55 of 93 sera collected at recurrent disease (59%). Elevated serum levels were detected significantly more often in patients with distant metastases than in patients with recurrent disease restricted to loco-regional areas (68% versus 19%). Presence of elevated serum level was associated with ERBB2 gene amplification and c-erbB-2 protein overexpression in tumour. None of the patients who had normal ERBB2 gene copy number in tumour had elevated serum levels. Although the usefulness in postoperative prediction of the presence of micrometastases is somewhat questionable, the results suggest c-erbB-2 related protein to represent a novel tumour marker in serum and other body fluids from breast cancer patients at the time of diagnosis and during treatment monitoring.

The neu-oncogene: more than a prognostic indicator?

Overexpression of the neu-protein, evidenced as membrane staining by immunohistochemistry, is detected in approximately 20% of invasive duct cell carcinomas, in approximately 50% of in situ duct cell carcinomas, and in almost 100% of cases of Paget's disease. Apart from a growth stimulatory effect, the molecule plays an important role in cell motility of tumor cells by the activity of a motility factor, which acts as a specific ligand for the neu-protein. The motility factor induces chemotaxis of neu-overexpressing breast cancer cells. The motility function of the neu-protein may lead to an increased metastatic potential of neu-overexpressing breast tumors. Also in Paget's disease of the breast, a motility factor secreted by epidermal keratinocytes attracts the neu-overexpressing Paget's cells by chemotaxis and leads to invasion of the epidermis by the tumor cells.

p53 but not erbB-2 expression is associated with rapid tumor proliferation in urinary bladder cancer

Tumor proliferation in bladder cancer is associated with tumor behavior. To assess the association between Ki-67 labeling index (LI), p53, and c-erbB-2 overexpression, formalin-fixed tissue samples of 160 patients with transitional cell carcinoma (TCC) of the urinary bladder were studied by immunohistochemistry. Ki-67 LI was strongly associated with tumor stage (P < .0001), tumor grade (P < .0001), and p53 status (P = .0014) but not with erbB-2 overexpression (P > .2). Ki-67 LI was higher in p53-positive tumors (19%) than in p53-negative tumors (14%) when all stages were compared. Ki-67 LI was independent of p53 expression in pTa tumors (p53-positive, 9%; p53-negative, 11%), showing that p53 overexpression alone is not sufficient to induce rapid tumor cell proliferation in pTa tumors. Ki-67 LI also was independent of p53 expression in pT2 to pT4 tumors (p53-positive, 20%; p53-negative, 23%), indicating that p53 expression is not necessary for rapid tumor cell proliferation in advanced stages. However, there was a striking difference in Ki-67 LI between p53-positive pT1 tumors (22.0% +/- 8.8 standard deviation [SD]; n = 20) and p53-negative pT1 tumors (9.7 +/- 8.3 SD; n = 22; P = .0001). These results suggest that increased proliferation in p53-positive pT1 tumors is caused by additional alterations that occur during tumor progression.

Cytoplasmic c-erbB-2 protein expression correlates with survival in Dukes' B colorectal carcinoma

The prognostic significance of c-erbB-2 expression was studied in paraffin wax embedded colorectal cancer tissue using a monoclonal antibody. One hundred and sixty-four patients with Dukes' B disease were studied. Membranous staining was not detected in any case. Cytoplasmic c-erbB-2 staining was seen in 55 cancers (33.5%). Cytoplasmic staining was unrelated to patient age (P = 0.31), sex (P = 0.69), tumour site (P = 0.69), size (P = 0.57), histological grade (P = 0.42) or ploidy status (P = 0.21) but was found more frequently in obstructing cancers (P = 0.03). Mean follow up of the patient population was 6.3 years. Five-year-survival estimated by the Kaplan-Meier life-table method was 47% for those with cytoplasmic c-erbB-2 staining and 77% for those without (log rank analysis; P < or = 0.0001). Stepwise regression analysis identified c-erbB-2 staining (relative risk, 2.51; P = 0.0005) and bowel obstruction (relative risk, 1.99; P = 0.015) as independent predictors of survival. It is suggested that cytoplasmic c-erbB-2 expression may provide a useful marker of tumour behaviour in Dukes' B colorectal cancer.

c-erbB-3 protein expression in human breast cancer: comparison with other tumour variables and survival

c-erbB-3 protein expression was investigated immunohistochemically in a series of 97 malignant breast tumours using the monoclonal antibody RTJ1. Twenty-eight cases (28.8%) showed c-erbB-3 overexpression, 31 cases (32%) showed normal levels of c-erbB-3 and 38 cases (39.2%) were c-erbB-3 negative. c-erbB-3 overexpression was positively but not significantly related to negative lymph node status and survival over a 10-year follow-up period.

Critical determination of the frequency of c-erbB-2 amplification in breast cancer

Tissues from 323 methacarn-fixed and paraffin-embedded breast cancers were assessed for c-erbB-2 gene amplification by differential polymerase chain reaction (dPCR). The sensitivity of dPCR was ascertained using cell lines with c-erbB-2 amplification, and the relationship between dPCR ratio value and gene copy number was established. In clinical material the technique was not affected by the DNA contribution of normal tissue elements or by cancer DNA ploidy change. c-erbB-2 gene amplification was detected in 55% of invasive cancers and in 66% of in situ cancers. c-erbB-2 protein overexpression in breast cancer cells, as determined by specific immunohistochemistry, was only detected in 11% of invasive cancers and 43% of in situ cancers. Comparisons show that a substantial number of cancers with c-erbB-2 amplification lack detectable protein overexpression. This illustrates the complex nature of c-erbB-2 gene disregulation in cancer and suggests that multiple combinations of biological events and consequences are possible.

Correlations between the mammographic features of ductal carcinoma in situ (DCIS) and C-erbB-2 oncogene expression. Nottingham Breast Team

PURPOSE

C-erbB-2 oncogene expression is found in 60% of DCIS cases. C-erbB-2 expression in DCIS has been shown to correlate with comedo subtype, large cell size, lymphoid infiltrate, nuclear pleomorphism, multinucleation and high mitotic rate. These findings have led to the suggestion that the subgroup of DCIS that expresses c-erbB-2 may be a biologically definable category with prognostic significance. The purpose of this study was to identify any differences in the mammographic appearances between DCIS which expresses c-erbB-2 and DCIS that does not express this oncogene.

MATERIALS AND METHODS

C-erbB-2 staining characteristics and preoperative mammograms were available for review in 126 patients with pure DCIS. All the mammograms were reviewed by a radiologist knowing the patient had DCIS but without any further pathological or immunohistochemical information.

RESULTS

C-erbB-2 positive DCIS showed the following features more commonly than c-erbB-2 negative disease: calcification (65 of 71 (92%) vs 28 of 39 (72%), P < 0.01), ductal distribution of calcification (51 of 65 (78%) vs 16 of 28 (57%), P < 0.05), rod-shaped calcification (53 of 65 (82%) vs 15 of 28 (54%), P < 0.01) and granular calcification (63 of 65 (97%) vs 24 of 28 (86%), P < 0.05). C-erbB-2 negative DCIS more commonly showed an abnormal mammogram without calcification than c-erbB-2 positive disease (11 of 39 (28%) vs 6 of 71 (8%), P < 0.01).

CONCLUSION

We have demonstrated significant differences in the mammographic features of c-erbB-2 positive and negative disease. As c-erbB-2 expression has been shown to correlate with aggressive histological features, the differences in the mammographic appearances between c-erbB-2 positive and c-erbB-2 negative DCIS may be of practical value.

c-erbB-2 oncoprotein is not an independent prognostic parameter in primary breast carcinoma. An immunohistochemical study

The prognostic significance of c-erbB-2 oncoprotein expression was studied using the monoclonal antibody, anti-c-erbB-2 (CB-11, BioGenex) and the avidin-biotin-complex (ABC) technique. Four hundred and ninety patients with primary breast carcinoma diagnosed at Gentofte Hospital in the period 1980-1985 were included. Information about treatment, relapse-free period and overall survival was obtained from the Danish Breast Cancer Co-operative Group (DBCG). The mean follow-up period was more than 10 years. Fifteen per cent of the tumours showed positive immunoreactivity for c-erbB-2. Oncoprotein expression was correlated with presence of lymph node metastases, type of tumour, high number of mitoses, severe nuclear pleomorphism, high histological grade (poor differentiation), and absence of steroid hormone receptors. By univariate analysis, expression of c-erbB-2 oncoprotein, was correlated with poorer overall survival and shorter disease-free period in the entire cohort and in patients with lymph metastases, but not in the group of patients without lymph node metastases. By multivariate analysis, c-erbB-2 failed to be an independent prognostic marker for either disease-free period or overall survival, whereas classical histopathological parameters such as presence of lymph node metastases, high number of mitoses, high histological grade (poor differentiation) and absence of progesterone receptors turned out to be of independent prognostic significance.

Simultaneous analysis of c-erbB-2 expression and DNA content in breast cancer using flow cytometry

The c-erbB-2 oncogene is frequently amplified and overexpressed in human breast cancer. We have studied the c-erbB-2 protein in conjunction with DNA content in frozen samples from breast cancers using flow cytometry. The cell suspensions were obtained by mechanical disaggregation followed by a short fixation in 1% paraformaldehyde. The level of c-erbB-2 expression was calculated as a fluorescence index, taking into account the relative amount of total cellular fluorescence compared to nonspecific fluorescence. The flow cytometric value correlated with immunohistochemical results obtained with the same monoclonal antibody (c-neu, clone 9G6). Overexpression of c-erbB-2 was significantly more frequent in DNA aneuploid tumors than in DNA diploid ones and correlated with increasing S-phase fraction and estrogen receptor negativity. In 10 DNA multiploid tumors, the different aneuploid stemlines uniformly expressed c-erbB-2, supporting the hypothesis that overexpression is an early event in breast cancer. Of the 172 tumors, the 37 (22%) judged as positive with immunohistochemistry showed a somewhat higher rate of distant recurrence than others (P = 0.14). The fluorescence index was significantly associated with prognosis (P = 0.0012), as it was also among the immunohistochemically positive cases. If the degree of overexpression is important, then flow cytometry could be a feasible technique for classification.

Demonstration of c-erbB-2 oncogene overexpression in salivary gland neoplasms by in situ hybridization

The level of c-erbB-2 cellular mRNA in 18 salivary gland tumours and in 7 normal salivary glands was determined by in situ hybridization using [35S] labelled RNA probes. Computer assisted quantitation of the autoradiographic signal indicated a significantly higher c-erbB-2 expression in the tumour group (22.64 grains per cell +/- 3.79; 95% CI) as compared to the non-neoplastic salivary gland tissue (4.11 +/- 0.90; 95% CI). The c-erbB-2 expression as measured by grain counts per cell for the pleomorphic adenomas (16.29 +/- 1.87; 95% CI), mucoepidermoid carcinomas (31.52 +/- 0.08; 95% CI) and the acinic cell carcinomas (44.24 +/- 17.11; 95% CI) were significantly greater than the expression for the normal group. The acinic cell carcinomas exhibited the greatest level of expression. As observed at the individual cell level, the autoradiographic signal was distributed uniformly in the neoplastic tissues, regardless of the cell type. This study confirms the hypothesis that the c-erbB-2 oncogene is overexpressed at the mRNA level in salivary gland tumours.

Breast cancer: prognostic significance of c-erb-B2 and int-2 amplification compared with DNA ploidy, S-phase fraction, and conventional clinicopathological features

The prognostic value of oncogene amplification and conventional clinicopathological features was determined in consecutive breast cancers detected during 5 months in 1975-1976 in 4 Swedish counties. Material was collected from 162 of the 179 patients and tumor size, nodal status, FSH, estrogen/progesterone receptor status, DNA ploidy and S-phase fraction determined. Tissues remaining from 80 patients were stored frozen until 1991, when amplification of the oncogenes c-erb-B2 and int-2 was determined. We show that c-erb-B2 amplification (but not int-2 amplification) and positive axillary nodal status show prognostic significance for both survival and relapse-free survival in univariate and multivariate analysis. The other examined factors showed no significance.

Prognostic association of c-erbB-2 oncogene amplification and protein overexpression in human breast cancer using archival tissues. A comparative study

The prognostic associations of c-erbB-2 gene amplification analysed by dot-blot hybridization and of c-erbB-2 protein overexpression assessed by immunohistochemistry (IHC) were compared in 161 patients with operable breast cancer using formalin fixed paraffin embedded archival tissues. The efficiency of the dot-blot technique to detect c-erbB-2 amplification was first validated by comparing the results of dot-blot with those of Southern blot hybridization in 134 tumour samples and there was an excellent correlation. In the main series of 161 samples, where results of IHC and dot-blot were compared, 35.4% showed c-erbB-2 overexpression and 17.4% showed gene amplification. Tumours showing overexpression of c-erbB-2 protein had a significantly shorter disease-free survival (DSF) and survival(s) compared to tumours showing no overexpression. A multivariate analysis revealed that c-erbB-2 overexpression was independently correlated with poor prognosis. On the other hand, no significant association between c-erbB-2 gene amplification and DFS or S was observed. We conclude that c-erbB-2 protein overexpression assessed by IHC is a superior prognostic indicator in operable breast cancer compared to c-erbB-2 gene amplification analysed by the dot-blot technique.

C-erbB-2 overexpression in primary breast cancer: independent prognostic factor in patients at high risk

The prognostic value of c-erbB-2 protein overexpression has been evaluated in 463 patients with operable breast cancer after a median follow-up of 66 months. Overexpression was observed in 99/463 (21%) of the breast tumors. It showed significant positive correlation to histological grade (p < 0.0001) and tumor size (p < 0.02). A relationship of borderline significance was observed between c-erbB-2 protein overexpression and negative or low estrogen receptor (ER) content. No significant correlation was found to lymph node involvement or proliferating tumor cell fraction as determined by the proliferating cell nuclear antigen (PCNA). After a median follow-up of 66 months (range 6 to 109 months), the overall survival of all patients amounted to 63%. Multivariate analysis revealed lymph node involvement, tumor size, histological grade, histological type, c-erbB-2 protein overexpression, progesterone receptor (PR) content, and oral contraceptive use as independent prognostic factors. In an univariate analysis, the overall survival amounted to 72% and 38% of tumor patients with negative and positive c-erbB-2 protein overexpression, respectively. The most significant finding is that c-erbB-2 overexpression has been recognized as an independent predictive factor in subsets of tumor patients who would be expected to have a generally poor prognosis, such as those indicating axillary lymph node involvement, large tumor size (> 2 cm), and PR negativity.

Analysis of c-erbB-2 amplification in salivary gland tumours by differential polymerase chain reaction

DNA samples extracted from 22 normal salivary glands, 38 salivary pleomorphic adenomas and 20 other salivary gland neoplasms were screened for amplification of the c-erbB-2 oncogene by a differential polymerase chain reaction (PCR). The samples were PCR amplified with primers specific for the c-erbB-2 oncogene and for a reference gene (interferon-gamma). A breast carcinoma cell line SKBR-3 known to contain c-erbB-2 amplification was used as positive control. Following gel electrophoresis, the intensity of the amplified DNA bands was determined by laser densitometry and the level of amplification of the c-erbB-2 oncogene was assessed from the intensity of the c-erbB-2 specific band relative to that of the interferon-gamma band. Of all the tumours detected, only the two poorly differentiated adenocarcinomas, two of the pleomorphic adenomas and one of the Warthin's tumours showed gene amplification at levels comparable to the breast carcinoma cell line. None of the normal salivary gland tissues was found to have amplification. Within the group of pleomorphic adenomas the average level of amplification was not significantly different from that observed in the normal salivary gland, or in total genomic DNA from unrelated tissue (P < or = 0.001, determined by a general linear model of statistical analysis). These results indicate that amplification of the c-erbB-2 oncogene is infrequent in salivary neoplasia. Thus, gene amplification alone cannot account for the high prevalence of c-erbB-2 overexpression demonstrated previously in salivary gland tumours. When present, c-erbB-2 amplification may be associated with a more aggressive behaviour.

Molecular biology of breast cancer

BACKGROUND

A gene responsible for an inherited predisposition to breast and ovarian cancer has been localized to the long arm of chromosome 17 and termed BRCA1. As well as being closely linked to breast/ovarian cancer cases, this gene may be involved in up to 45% of site-specific breast cancers. The identification and cloning of the BRCA1 gene is imminent, and will facilitate the screening and counselling of families at risk of breast cancer, and in the longer term may open up new therapeutic possibilities. The tumour suppressor gene TP53 is mutated in 25%-40% of cases of sporadic breast cancer, and is associated with an aggressive tumour phenotype and poor prognosis in both node-positive and node-negative cases. The pattern of mutations in this tumour suppressor gene shows a higher than expected frequency of G to T transversions, mostly restricted to the highly conserved domain in exons 5 to 8. In many, but not all cases, point mutation of one allele is accompanied by deletion of the remaining normal allele at chromosome 17p13. Abnormalities of TP53 appear to be relatively early events in tumorigenesis, being present in ductal carcinoma in situ lesions. The retinoblastoma gene RB1 shows a variety of abnormalities in about 20% of breast cancers, and there may be an association with TP53 mutations. Other abnormalities which occur with a particularly high incidence in breast cancer include allele loss at chromosome 1p/1q, 3p, 6q, 11p, 16q and 18q. The ERBB2 oncogene encodes a transmembrane receptor tyrosine kinase whose ligand has recently been claimed to be the heregulin family in man.(ABSTRACT TRUNCATED AT 250 WORDS)

Oestrogen-regulated genes in breast cancer: association of pLIV1 with lymph node involvement

In order to isolate markers of oestrogen responsiveness in breast cancer, we have cloned a number of oestrogen-regulated genes. Two of these, pLIV1 and pLIV2 (pS2), have been shown to be predominantly expressed in oestrogen receptor (ER)+ tumours. In this study, we examined their expression in relation to various clinical and histopathological features of breast cancer, and showed that pLIV1, but not pS2, is significantly associated with lymph node involvement (P < 0.01), while pS2 is more frequently observed in premenopausal patients (P < 0.05). Subdivision of the pLIV1 data by ER and nodal status of the tumour identified a highly significant association between pLIV1 expression and lymph node involvement in ER-positive disease, with 15/24 (63%) ER+ pLIV1+ tumours showing nodal involvement. Conversely, 20/23 (87%) ER+ pLIV1- patients were lymph node-negative (P < 0.001). Subdivision of the pS2 data by ER status did not reach significance. The application of pLIV1 as a marker of lymph node involvement was further exemplified in small tumours (< < 2 cm), where 11/12 (92%) lymph node-positive patients expressed pLIV1, while 17/22 (77%) node-negative patients were pLIV1 negative (P < 0.001). Similarly, pLIV1 expression identified lymph node involvement in moderately differentiated tumours (P < 0.01), but was independent of vascular invasion. pLIV1 may, therefore, represent a candidate gene for metastatic spread in ER+ breast cancer.

What's new in breast cancer? Molecular perspectives of cancer development and the role of the oncogene c-erbB-2 in prognosis and disease

The oncogene c-erbB-2 is frequently amplified in human breast carcinoma. The c-erbB-2 gene is present as a single copy in normal cells, and has been mapped to chromosome 17 in the region 17q 12-21.32. c-erbB-2 encodes a transmembrane glycoprotein known as p185. The intracellular component of p185 has tyrosine kinase activity; the extracellular domain has a structure resembling a growth factor receptor. c-erbB-2 amplification, p185 overexpression and levels of transcribed c-erbB-2 specific messenger RNA have been studied in a large number of breast carcinomas using a variety of techniques. In general, overexpression of p185 oncoprotein reflects various levels of DNA amplification, though in some cases amplification can be detected in the absence of overexpression of p185 and similarly overexpression of p185 can be present without detectable levels of c-erbB-2 amplification. This findings suggests that multiple mechanisms may be responsible for overexpression. c-erbB-2 amplification and/or overexpression occurs in almost all cases of high grade duct carcinoma in-situ, but has been reported in only 10%-40% of infiltrating duct carcinoma. c-erbB-2 amplification or overexpression occurs rarely in invasive lobular carcinoma, and has not been detected in ductal or lobular epithelial hyperplasia, or in atypical ductal or atypical lobular hyperplasia. It is generally believed that c-erbB-2 amplification/overexpression is an important independent prognostic indicator in breast carcinoma, identifying a subset of patients with poor prognosis tumours, particularly if axillary node metasases are present. However, many unanswered questions remain regarding c-erbB-2 and its role in breast cancer development and progression. The causes of c-erbB-2 amplification are unknown. There is no evidence of mutations in the human gene which might cause amplification or overexpression. The significance of the differences in levels of c-erbB-2 amplification/overexpression in in-situ duct carcinoma and associated invasive duct carcinoma has not been established. Amplification or overexpression have not been reported in atypical duct hyperplasia, a proposed precursor of duct carcinoma in-situ, yet overexpression occurs almost always in high grade duct carcinoma in-situ. c-erbB-2 may play a critical role in the development of a clonal in-situ, proliferation of high histological grade, yet does not obviously influence the acquisition of an invasive phenotype. We would postulated that this instability in amplification/overexpression is of biological significance, and if better understood may aid in the study of progression of human breast carcinoma.

Establishment and characteristics of two new human mammary carcinoma lines serially transplantable in nude mice

Two human mammary carcinomas of postmenopausal women were successfully transplanted into nude mice. Both tumours were classified as epidermal-growth-factor-, oestradiol- and progesterone-receptor-negative and c-erbB2-protein-positive. Histological studies of the primary tumours (4000 and 4151) revealed ductal invasive mammary carcinomas. In the first passages the precondition for the growth of breast carcinoma 4000 were pretreatments of the nude mice with oestradiol and peanut oil before transplantation. The mammary carcinomas 4000 and 4151 described here are suitable for in vivo testing of antineoplastic substances and for biological studies.

Prognostic significance of Helix pomatia lectin and c-erbB-2 oncoprotein in human breast cancer

We investigated the prognostic significance of Helix pomatia lectin (HPA) staining on disease-free and overall survival in 120 primary breast carcinomas. HPA staining was present in 58 (48%) of these carcinomas. It was significantly associated with axillary lymph node metastases (P < 0.001) and c-erbB-2 expression (P < 0.01). A univariate study revealed that disease-free and overall survival were significantly correlated with clinical stage, tumour size, axillary lymph node metastases. HPA staining and c-erbB-2 expression. In a multivariate study, all previous prognostic indicators except HPA staining and c-erbB-2 expression were independent factors. However, stratifying the patients on the basis of HPA and c-erbB-2 status suggested that HPA +/c-erbB-2+ status was predictive of a higher incidence of axillary lymph node metastases (P = 0.000001) and a poorer overall (P < 0.0002) and a shorter disease-free (P < 0.000006) survival when compared with the other subgroups, although this combination did not provide any additional prognostic information for overall (P = 0.3544) or disease-free (P = 0.7152) survival by a multivariate analysis. For patients in whom axillary lymph node dissection has not been performed, therefore, HPA and c-erbB-2 status seems to be a powerful tool to discriminate subpopulations with a high recurrence risk and shorter survival who should undergo more aggressive therapy.