Clinical breast cancer, new developments in selection and endocrine treatment of patients

Correlation between pS2 protein positivity, steroid receptor status and other prognostic factors in breast cancer

The cytosolic levels of pS2, an estrogen-regulated protein, were measured in 100 cases of primary breast cancer and related to several conventional histological and biochemical prognostic factors. The data were statistically analyzed on the basis of two different cutoff points for pS2: 4 and 11 ng/mg of cytosolic proteins. pS2 positivity (cutoff 11 ng/mg) was shown to be associated with smaller tumor size (p = 0.05), a higher differentiation grade (p = 0.007) and a smaller number of mitoses (p = 0.004), but not with menopausal status, lymph node involvement, cathepsin D levels, or proliferative activity determined by the monoclonal antibody Ki67. With the cutoff of 4 ng/mg, the statistical significance was confirmed only for the number of mitoses (p = 0.03), which was also the most closely related covariate in multivariate analysis (p = 0.008). As regards steroid receptor status, a significant difference was observed between pS2+ and pS2– cases (Chi-square = 8.9; p - 0.04, cutoff 4 ng/mg). In conclusion, pS2 positivity, being preferentially expressed in hormone-dependent cells and related to other well-known positive markers, may either indicate a good prognosis or predict responsiveness to endocrine treatment.

Combined targeting of Raf and Mek synergistically inhibits tumorigenesis in triple negative breast cancer model systems

Aberrant Ras-MAPK signaling from receptor tyrosine kinases (RTKs), including epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor-2 (HER2), is a hallmark of triple negative breast cancer (TNBC); thus providing rationale for targeting the Ras-MAPK pathway. Components of this EGFR/HER2-Ras-Raf-Mek-Erk pathway were co-targeted in the MDA-MB-231 and MDA-MB-468 human TNBC cell lines, and in vitro effects on signaling and cytotoxicity, as well as in vivo effects on xenograft tumor growth and metastasis were assessed. The dual EGFR/HER2 inhibitor lapatinib (LPN) displayed greater cytotoxic potency and MAPK signaling inhibition than the EGFR inhibitor erlotinib, suggesting both EGFR and HER2 contribute to MAPK signaling in this TNBC model. The Raf inhibitor sorafenib (SFN) or the Mek inhibitor U0126 suppressed MAPK signaling to a greater extent than LPN; which correlated with greater cytotoxic potency of SFN, but not U0126. However, U0126 potentiated the cytotoxic efficacy of LPN and SFN in an additive and synergistic manner, respectively. This in-series Raf-Mek co-targeting synergy was recapitulated in orthotopic mouse xenografts, where SFN and the Mek inhibitor selumitinib (AZD6244) inhibited primary tumor growth and pulmonary metastasis. Raf and Mek co-inhibition exhibits synergy in TNBC models and represent a promising combination therapy for this aggressive breast cancer type.

Correlation between epidermal growth factor receptor and tumor stem cell markers CD44/CD24 and their relationship with prognosis in breast invasive ductal carcinoma

We studied the correlation between epidermal growth factor receptor (EGFR) and the tumor stem cell markers CD44/CD24 in breast invasive ductal carcinoma (BIDC) and their relationship with prognosis. We analyzed the clinical data of 139 BIDC cases retrospectively, detecting EGFR, CD44, and CD24 expressions in tumor tissue using immunohistochemistry. The proportion of EGFR-, CD44-, and CD24-positive cases was 59.0, 62.3, and 30.9 %, respectively. The proportion of CD44-positive [76.9 % (p < 0.05)] and EGFR-positive [67.2 % (p = 0.108)] cases in the triple-negative breast cancer (TNBC) group was higher than that of the non-TNBC group. In the non-TNBC group, 36.5 % was CD24-positive, higher than that in the TNBC group but not statistically significant. The proportion of CD44-positive cases was significantly higher in the EGFR-positive group than in the EGFR-negative group (p = 0.017). EGFR-positive cases were significantly correlated with premenopausal status (p = 0.036), distant metastasis (p = 0.018), and estrogen receptor-negative status (p = 0.020). CD44-positive status was significantly correlated with human epidermal growth receptor 2 (HER2)-negative (p = 0.023), estrogen receptor-negative (p = 0.021), and progesterone receptor-negative status (p = 0.004). CD24-positive status was significantly correlated with HER2-positive status (p = 0.001). Kaplan-Meier survival analysis showed that TNBC patients had shorter survival. EGFR-positive and CD44-positive status were both correlated with shorter survival in the lymph node- and HR-negative groups, while CD24 positive was significantly correlated with poor survival in lymph node-negative and HR-positive patients. EGFR and CD44 expressions have a significantly positive correlation (p = 0.017) in BIDC. Patients both EGFR and CD44 positive had the worst outcome.

Zinc and cancer: implications for LIV-1 in breast cancer

Zinc is a trace mineral which is vital for the functioning of numerous cellular processes, is critical for growth, and may play an important role in cancer etiology and outcome. The intracellular levels of this mineral are regulated through the coordinated expression of zinc transporters, which modulate both zinc influx as well as efflux. LIV-1 (ZIP6) was first described in 1988 as an estrogen regulated gene with later work suggesting a role for this transporter in cancer growth and metastasis. Despite evidence of its potential utility as a target gene for cancer prognosis and treatment, LIV-1 has received relatively little attention, with only three prior reviews being published on this topic. Herein, the physiological effects of zinc are reviewed in light of this mineral’s role in cancer growth with specific attention being given to LIV-1 and the potential importance of this transporter to breast cancer etiology.

Endocrine therapy of metastatic breast cancer

Breast cancer growth and dissemination is regulated by estrogen and different growth factor receptor signalling pathways. The increasing knowledge of the biology of breast cancer regarding the interaction of these signalling pathways provides a tool to understand endocrine therapies response and resistance mechanisms. In patients with slowly progressive disease, no visceral involvement, and minimal symptoms, endocrine therapy could be the strategy of choice, even if the tumor has low estrogen receptor expression. Ovarian suppression and tamoxifen are recommended for premenopausal patients whether aromatase inhibitors are the option for postmenopausal ones. Chemotherapy still remains as the right alternative for hormone unresponsive or resistant patients. This is a review focused on the different strategies and combinations of endocrine therapies for metastatic breast cancer patients considering the potential strategies clinically tested to overcome resistance and the different treatments of choice available for each scenario of disseminated disease.

Establishment and characterization of new mammary adenocarcinoma cell lines derived from double transgenic mice expressing GFP and neu oncogene

A new murine cell line, named GFPneu, was established from a mammary adenocarcinoma arising in double transgenic MMTVneu x CMV-GFP mice. Breast tumours develop in 100% of females after 2 months latency, as a result of the over-expression of the activated rat neu oncogene in the mammary glands. All tissues, and in particular the breast tumours, express the GFP protein. This cell line was tumorigenic when inoculated into nude mice and the derived tumours showed the same histological features as the primaries from which they were isolated. Their histopathology reproduces many characteristics of human breast adenocarcinomas, in particular their ability to metastasize. The GFP marker allows us to visualize the presence of lung metastases in fresh tissues immediately, to confirm the histopathology. From a lung metastatic fluorescent nodule, we derived a further cell line, named MTP-GFP, which we also characterized. These two cell lines could be useful to study the role played by the neu oncogene in the maintenance of the transformed phenotype, in the metastatic process, to test novel therapeutic strategies to inhibit primary tumour growth and to observe the generation of distant metastases.

The Role of Ovarian Ablation in the Management of Breast Cancer

In recent years the role of ovarian ablation as a therapeutic modality not only in the prevention but also in the treatment of breast cancer has reemerged after its initial use more than a century ago. BRCA-1 and BRCA-2 mutation carriers have an 85% lifetime risk of developing breast cancer. Bilateral salpingo-oophorectomy is effective in reducing the risk of developing breast cancer in both BRCA-1 and BRCA-2 mutation carriers by 50%. Tamoxifen reduces the risk of breast cancer in BRCA-2 mutation carriers, but not in BRCA-1 mutation carriers. Breast cancer arising in BRCA-1 mutation carriers is often estrogen receptor (ER) negative, unlike breast cancer developing in BRCA-2 mutation carriers. Sixty percent of premenopausal patients with breast cancer have ER-positive disease and 25% of breast cancer patients are premenopausal at diagnosis. The Early Breast Cancer Trialists' Collaborative Group review has shown ovarian ablation to be an effective adjuvant therapy for premenopausal breast cancer patients less than 50 years of age. But the Early Breast Cancer Trialists' overview also shows the benefit of ovarian ablation is uncertain if these patients also receive chemotherapy. Does the overview underestimate the efficacy of ovarian ablation? Some patients in these trials were ER negative. Most women less than 50 years of age who receive adjuvant chemotherapy become menopausal. So there is a need to test ovarian function suppression in the group who can benefit, or in other words, those that remain premenopausal after chemotherapy and have endocrine responsive breast cancer.

Oestradiol enhances tumour regression induced by B7-1/IL-2 adenoviral gene transfer in a murine model of breast cancer

The majority of breast cancers are oestrogen dependent and although current treatment strategies have improved, approximately 50% of the patients will develop metastasis. New treatments that result in long-term systemic immunity are therefore being developed. We have previously shown that adenoviral gene transfer of B7-1/IL-2 to murine breast cancer induces a high rate of complete tumour regression and systemic immunity. Since oestrogens not only affect breast cancer but also have been shown to modulate immune function and secretion of immune-regulatory cytokines, we explored whether administration of oestradiol altered the immune response induced by an adenoviral vector expressing B7-1/IL-2. An oestrogen-dependent murine breast cancer tumour was used in ovariectomised mice, supplemented either oestradiol or placebo. We report the somewhat unexpected finding that intratumoral injection of adenovirus expressing B7-1/IL-2 induces complete tumour regression in 76% of oestradiol-supplemented mice, while only 18% of the tumours regressed in the oestrogen-depleted group. Cured mice in both groups exhibited a similar CTL response against the tumour antigen. However, intratumoral IFN-gamma levels, 2 days after B7-1/IL-2 injection, were significantly higher in mice treated with oestradiol compared to placebo. This may be one mechanism explaining the higher response rate of tumours in oestradiol-replenished mice.

Combination endocrine therapy in the management of breast cancer

Combination endocrine therapy has long been sought after as a means to better treat breast cancer. Agents that suppress estrogen production are given with agents that suppress estrogenic activity at the cellular level. Historically, these combinations have resulted in initial improvements in response rates, but relapse-free and overall survival were not significantly improved. Also, the increased toxicity seen with these regimens was limiting. New endocrine therapies with more potent activity and less toxicity have led to a resurgence of this idea in the management of breast cancer. Complete estrogen blockade has been compared with single-agent treatments in many different settings. The endocrine effects of this type of therapy are intriguing, but apparently do not readily predict a clinical advantage. The combination of an aromatase inhibitor and an antiestrogen, despite pharmacokinetic interactions, may prove to be beneficial. Results from ongoing trials are eagerly awaited to further address this question in postmenopausal breast cancer patients. For premenopausal breast cancer patients the options are more complex. Clinical outcomes with leutinizing hormone releasing hormone (LHRH) agonists plus aromatase inhibitors are limited to very small phase II studies and are not clearly superior to single-agent therapy. Clinical data in the metastatic setting with premenopausal patients favor the use of an LHRH agonist with tamoxifen over the use of an LHRH agonist alone. However, a similar comparison with tamoxifen alone is lacking with only one trial including this as a treatment arm. Adjuvant therapy with this combined endocrine approach (LHRH agonist plus antiestrogen) has been more extensively studied, but lacks crucial comparisons necessary for making complex treatment decisions. Hopefully, through investigative diligence and ingenuity this issue can be adequately understood. However, many exciting new agents are on the horizon that offer hope to further advance the progress made to date although further confounding the questions already answered.

Combined tamoxifen and luteinizing hormone-releasing hormone (LHRH) agonist versus LHRH agonist alone in premenopausal advanced breast cancer: a meta-analysis of four randomized trials

PURPOSE

The logic behind the application of luteinizing hormone-releasing hormone (LHRH) agonists in combination with tamoxifen in premenopausal women is that LHRH agonists on the one hand suppress the tamoxifen-induced stimulation of the pituitary-ovarian function and, on the other hand, seem as effective as surgical castration. This meta-analysis combines all randomized evidence to compare the combined treatment with LHRH agonist alone with respect to overall survival, progression-free survival, and objective response in premenopausal women with advanced breast cancer.

PATIENTS AND METHODS

Four clinical trials randomizing a total of 506 premenopausal women with advanced breast cancer to LHRH agonist alone or to the combined treatment of LHRH agonist plus tamoxifen were identified. Meta-analytic techniques were used to analyze individual patient data from these trials.

RESULTS

With a median follow-up of 6.8 years, there was a significant survival benefit (stratified log-rank test, P = .02; hazards ratio [HR] = 0.78) and progression-free survival benefit (stratified log-rank test, P = .0003; HR = 0.70) in favor of the combined treatment. The overall response rate was significantly higher on combined endocrine treatment (stratified Mantel Haenszel test, P = .03; odds ratio = 0.67).

CONCLUSION

The combination of LHRH agonist plus tamoxifen is superior to LHRH agonist alone in premenopausal women with advanced breast cancer. Therefore, if a premenopausal woman with advanced breast cancer is thought to be suitable for endocrine treatment, it is proposed that the combination of a LHRH agonist plus tamoxifen be considered as the new standard treatment.

Value of estrogenic recruitment before chemotherapy: first randomized trial in primary breast cancer

PURPOSE

Several preclinical studies showed that short-term pretreatment of breast cancer cells with estrogens can increase the antitumor efficacy of different cytotoxic drugs. Some early clinical studies in patients with advanced breast cancer did seem to support these findings. Therefore, the efficacy of estrogenic recruitment followed by chemotherapy was compared with that of chemotherapy alone in a randomized phase III study in women with lymph node-positive primary breast cancer.

PATIENTS AND METHODS

Three hundred twenty-eight patients with stage II/IIIA breast cancer who were younger than 66 years of age were randomly allocated to chemotherapy with fluorouracil, doxorubicin, and cyclophosphamide (FAC) or FAC plus pretreatment with ethinyl estradiol (EE(2)). FAC (500, 50, and 500 mg/m(2), respectively) was administered intravenously once every 4 weeks for four cycles. EE(2) (0.5 mg) was administered orally, both 24 hours and immediately preceding FAC chemotherapy.

RESULTS

Patient and tumor characteristics and chemotherapy dosages were comparable in both treatment groups. Of 318 assessable patients, with a median follow-up of 6.8 years, 177 patients had a relapse and 127 died. No significant differences were observed between the two treatment groups with respect to relapse-free, local recurrence-free, and overall survival according to univariate and multivariate analyses adjusted for age, menopausal status, tumor size, grade, number of positive nodes, and steroid-receptor status. The power for the detection of an increase of 50% in the median relapse-free survival was 80%.

CONCLUSION

Estrogenic recruitment of breast cancer cells before FAC chemotherapy did not influence the efficacy of adjuvant chemotherapy in stage II/IIIA breast cancer patients after a follow-up of 6.8 years.

pS2 (TFF1) levels in human breast cancer tumor samples: correlation with clinical and histological prognostic markers

The expression of pS2 (TFF1) has been previously shown to identify patients with improved response to anti-hormonal therapy and more favorable outcome. In the current study, 100 human breast carcinoma samples obtained from the Manitoba Breast Tumor Bank were analyzed for pS2 mRNA using a quantitative, competitive reverse transcriptase-polymerase chain reaction (qcRT-PCR) assay. A pS2/beta-actin cut-off criterion of 0.010 was established to classify tumors as either pS2 positive or pS2 negative. pS2 mRNA levels were positively associated with both ER and PR, with the majority of ER+ (59%) and PR+ (60%) tumors also being positive for pS2. In addition, a significant linear correlation was observed between the amount of pS2 mRNA and ER (p < 0.0001) and PR (p < 0.0001) protein. pS2 mRNA levels also exhibited an inverse association with tumor size and histological grade, consistent with the observation that pS2 is primarily expressed in small (T < 2.0 cm), but well differentiated tumors (Grades I and II). No associations were observed with tumor cell type, patient age, or lymph node status. The strong correlation displayed between pS2 and a number of currently used breast cancer prognostic markers supports the clinical use of pS2 to further assess tumor status and patient outcome.

The pS2/TFF1 trefoil factor, from basic research to clinical applications

pS2/TFF1 trefoil factor is normally expressed in the stomach, and is found ectopically in gastrointestinal inflammatory disorders and in various carcinomas. It is involved in stomach ontogenesis and in the maintenance of the integrity of the mucosa, and may represent a pharmacological tool for prevention and healing of gastrointestinal ulcerations. In breast cancer, it can be used to select patients suitable for hormone therapy. pS2/TFF1 is a pleiotropic factor involved in mucin polymerization, cell motility, cell proliferation and/or differentiation, and possibly in the nervous system.

Feasibility, endocrine and anti-tumour effects of a triple endocrine therapy with tamoxifen, a somatostatin analogue and an antiprolactin in post-menopausal metastatic breast cancer: a randomized study with long-term follow-up

Suppression of the secretion of prolactin, growth hormone and insulin-like growth factor 1 (IGF-1) might be important in the growth regulation and treatment of breast cancer. Because oestrogens may counteract the anti-tumour effects of such treatment, the combination of an anti-oestrogen (tamoxifen), a somatostatin analogue (octreotide) and a potent anti-prolactin (CV 205-502) might be attractive. In this respect, we performed a first exploratory long-term study on the feasibility of combined treatment and possible clear differences in endocrine and anti-tumour effects during such combined treatment vs standard treatment with tamoxifen alone. Twenty-two post-menopausal patients with metastatic breast cancer (ER and/or PR positive or unknown) were randomized to receive either 40 mg of tamoxifen per day or the combination of 40 mg of tamoxifen plus 75 microg of CV 205-502 orally plus 3 x 0.2 mg of octreotide s.c. as first-line endocrine therapy. An objective response was found in 36% of the patients treated with tamoxifen alone and in 55% of the patients treated with combination therapy. Median time to progression was 33 weeks for patients treated with tamoxifen and 84 weeks for patients treated with combination therapy, but the numbers are too small for hard conclusions. There was no difference in overall post-relapse survival between the two treatment arms. With respect to the endocrine parameters, there was a significant decrease of plasma IGF-1 levels in both treatment arms, whereas during combined treatment plasma growth hormone tended to decrease and plasma prolactin levels were strongly suppressed; in some patients insulin and transforming growth factor alpha (TGF-alpha) decreased during the triple therapy. Although there was no significant difference in mean decrease of plasma IGF-1 levels between the two treatment arms, combined treatment resulted in a more uniform suppression of IGF-1. Therefore, the addition of a somatostatin analogue and an anti-prolactin may potentially enhance the efficacy of anti-oestrogens in the treatment of breast cancer owing to favourable endocrine and possible direct anti-tumour effects. Large phase III trials using depot formulations (to increase the feasibility) of somatostatin analogues are warranted to demonstrate the potential extra beneficial anti-tumour effects of such combination therapy.

Establishment and characterization of a new mammary adenocarcinoma cell line derived from MMTV neu transgenic mice

A new murine cell line, named MG1361, was established from mammary adenocarcinomas arising in a MMTV-neu transgenic mouse lineage where breast tumors develop in 100% of females, due to the overexpression of the activated rat neu oncogene in the mammary gland. The MG1361 cell line shows an epithelial-like morphology, has a poor plating efficiency, low clonogenic capacity, and a doubling time of 23.8 hours. Karyotype and flow cytometry analysis revealed a hypotetraploid number of chromosomes, whereas cell cycle analysis showed 31.2% of cells to be in the G1 phase, 21.4% in S and 47.4% in G2 + M. This cell line maintains a high level of neu expression in vitro. The MG1361 cell line was tumorigenic when inoculated in immunodeficient (nude) mice and the derived tumors showed the same histological features as the primary tumors from which they were isolated. MG1361 cells were positive for specific ER and PgR binding which was competed by tamoxifen, making this cell line useful for the evaluation of endocrine therapy. Moreover, they were sensitive to etoposide treatment, suggesting that they could be a model for the study of chemotherapy-induced apoptosis. As the tumors arising in MMTV-neu transgenic mice have many features in common with human mammary adenocarcinomas (Sacco et al., Gene Therapy 1995; 2: 493-497), this cell line can be utilized to perform basic studies on the role of the neu oncogene in the maintenance of the transformed phenotype, and to test novel protocols of therapeutic strategies.

Predictive value of c-erbB-2, p53, cathepsin-D and histology of the primary tumour in metastatic breast cancer

The value of various prognostic factors in breast cancer patients has been determined in a number of studies. Few reports have been published on the dependence of treatment outcome on histological and immunohistochemical characteristics in the primary tumour in patients with metastatic disease. We studied the incidence and prognostic value of histological and molecular abnormalities in the primary tumour of patients who had developed metastatic breast cancer. Eligible patients received a fluorouracil, epirubicin and cyclophosphamide (FEC) regimen either once a week or once every 4 weeks. Adequate specimens for various analyses were available from 127 patients. Median follow-up time of the patients ranged from 15 to 101 months. In this study, the histological grade of the malignancy best predicted response to chemotherapy (P < 0.0005). Most of the responses were observed in patients with grade 1 tumours; in this group, time to progression was delayed. C-erb B-2 gene amplification and oncoprotein expression had no predictive value. Neither p53 nor cathepsin-D predicted treatment outcome after chemotherapy. None of the factors had an effect on overall survival. Among breast cancer patients who received anthracycline-containing chemotherapy, response to treatment correlated with histological grade. In patients with histological grade 1 breast cancer, the time to progression was longest. However, overall survival was not affected by histological grade nor the other parameters tested. In addition to histological grade, other prognostic factors that are not included in this study need to be identified to determine which patients with metastatic breast cancer would benefit from cytotoxic treatment.

Novel endocrine therapies in breast cancer

Endocrine therapy of breast cancer consists of a variety of both medical and surgical ablative treatment modalities, but ablative therapy is increasingly replaced by medical treatment. Most endocrine therapies have more than one endocrine effect, frequently together with direct growth inhibitory actions via receptors. Endocrine therapy can be effective in all phases of the disease, but curative only in early disease while in advanced cancer it can only prolong survival. In the past decade the number of available endocrine agents has been drastically increased. Novel approaches in the endocrine therapy of breast cancer are application of new antiestrogens, antiprogestins, new potent aromatase inhibitors, analogues of luteinizing hormone-releasing hormone (LHRH-A) and somatostatin, inhibitors of prolactin secretion, vitamin A and D analogues, bisphosphonates, growth factor antagonists, tyrosine protein kinase inhibitors, protease inhibitors, inhibitors of angiogenesis, radiolabeled hormones and monoclonal antibodies. New cell biological factors such as oncogenes and suppressorgenes, secretory proteins and membrane receptors can be used not only as prognostic factors but also for prediction of type of response to endocrine and chemotherapy. Thus, these cell biological parameters can be used to select high and low risk patients, type of systemic treatment, and can also be used as targets for new treatment modalities. Future studies on treatment of all stages of disease will increasingly focus on promising combined treatment modalities.

Intratumoral injection of an adenovirus expressing interleukin 2 induces regression and immunity in a murine breast cancer model

Rodent tumor cells engineered to secrete cytokines such as interleukin 2 (IL-2) or IL-4 are rejected by syngeneic recipients due to an enhanced antitumor host immune response. An adenovirus vector (AdCAIL-2) containing the human IL-2 gene has been constructed and shown to direct secretion of high levels of human IL-2 in infected tumor cells. AdCAIL-2 induces regression of tumors in a transgenic mouse model of mammary adenocarcinoma following intratumoral injection. Elimination of existing tumors in this way results in immunity against a second challenge with tumor cells. These findings suggest that adenovirus vectors expressing cytokines may form the basis for highly effective immunotherapies of human cancers.

Oncogene amplification and prognosis in breast cancer: relationship with systemic treatment

In the present study, we aimed to clarify the potential of oncogene amplifications as markers for the prediction of (i) (relapse-free) survival, (ii) response to first-line endocrine therapy and (iii) subsequent chemotherapy in patients with recurrent breast cancer. To attain this goal, amplification of different oncogenes (HER-2/neu, c-MYC and INT-2) was studied in primary tumors of a series of 259 patients with breast cancer (median follow-up of 72 mo). Of these tumors, 49.8% did not contain an amplification of any of the oncogenes studied, whereas in the amplified subgroup, INT-2 was amplified in 13%, HER-2/neu in 24% and c-MYC in 20% of the tumors. In univariate analysis, INT-2 amplification was associated with an increased risk of relapse (p < 0.03), especially in the subgroups of 85 node-negative (p = 0.05) and 156 ER/PgR-positive patients (p = 0.01). Cox multivariate regression analysis showed that c-MYC was the only oncogene whose amplification was significantly related with the rate of relapse. With respect to amplification in patients developing metastatic disease, who received first-line hormonal therapy (n = 114), HER-2/neu amplification was associated with a less favorable response to endocrine therapy (objective response rate only 17% and a progression-free survival (PFS) of only 4% at 12 mo). Interestingly, distinct INT-2 amplification might predict a better response to endocrine therapy (objective response rate of 56%, and a PFS after relapse of 42% at 12 mo).(ABSTRACT TRUNCATED AT 250 WORDS)

Prognostic factors in early breast carcinoma

Several investigators, the SEER data, and the ECOG/Intergroup study have shown that patients with small tumors (< 0.5 cm) have a recurrence rate of less than 2%, compared to 20-25% for large tumors (> or = 5 cm). Nuclear grade and tumor differentiation are established indicators; however, the interobserver lack of concordance has thwarted their use in clinical trials. The presence of peritumoral lymphatic and blood vessel invasion (PLBI) is associated with a relative risk of recurrence of 4.7. The predictive value of the presence of hormone receptors in tumors is associated with a favorable disease free and overall survival difference of 8-10%; however, this advantage is being eroded by the early appearance of other factors, such as the epidermal growth factor receptor (EGFR), proliferative capacity (S-phase), nuclear grade, and HER-2/neu oncogene. Concordance among the different methods of hormone-receptor assay (immunocytochemical, sucrose gradient, and dextran-coated charcoal) is essential to refine the true value of these factors. DNA flow cytometry measurements of ploidy (DNA content) and S-phase fraction are the most characterized of the prognostic factors. There are conflicting reports regarding the clinical significance of ploidy status, while measurements of S-phase fraction clearly indicate a robust association with disease free and overall survival. Our data continue to show that S-phase, but not ploidy, can predict time to recurrence significantly in untreated patients, even when data are stratified for tumor size. HER-2/neu oncogene is expressed in about 50% of ductal carcinoma in situ and 14% of invasive ductal carcinoma. The presence of this oncogene at high copy number may be a useful independent marker of poor prognosis and may be associated with drug resistance and correlated with tumor recurrence and shorter survival. EGFR could be measured in most breast tumors, and the level of its expression has inversely correlated with estrogen receptor protein expression. The value of EGFR as a predictor of prognosis remains controversial and is still being investigated. Cathepsin-D provides a provocative biologic rationale but is hindered by different and incongruent methods of analysis. The majority of large studies with more than 3-years' follow-up suggests that high cathepsin-D levels may be predictive of greater recurrence and lower survival. Angiogenesis has been implicated as a critical component of the metastatic process. Early studies show that tumor angiogenesis is an independent and highly significant prognostic indicator, and its presence may suggest the selection of "anti-angiogenic therapy."(ABSTRACT TRUNCATED AT 400 WORDS)

pS2 and response to adjuvant hormone therapy in primary breast cancer

We reviewed 319 primary breast tumours for cytosolic pS2 content, with a median follow-up of 6 years. pS2 status correlated positively with oestradiol and progesterone receptors and negatively with Scarff, Bloom and Richardson grade. pS2 positivity was associated with longer overall survival, particularly in patients who received hormone therapy, in whom pS2 status was also predictive of the response to therapy.

The prognostic value of epidermal growth factor receptor (EGF-R) in primary breast cancer: results of a 10 year follow-up study

In a study on 214 patients with primary breast cancer (median follow-up 8.5 yr, maximum follow-up 15 yr), EGF-R was negatively correlated to estrogen receptor and progesterone receptor, whereas no association was found with age, lymph node status, and tumor size. Initially, after a follow-up of 5 yr, there was a tendency to a significant association between EGF-R levels and tumor recurrence rate (p = 0.08). Patients with tumors containing intermediate levels of EGF-R experienced a longer relapse-free survival (RFS) than did patients with tumors possessing lower or higher levels of EGF-R. This effect was most pronounced in the subgroup of patients with positive axillary lymph nodes. However, after 10 yr follow-up, this association appears to be lost (p = 0.28) as shown in this update. A similar phenomenon was observed for the ER. While at 5 yr follow-up ER status had significant prognostic value (p = 0.01), at 10 yr follow-up this significance also appears to be lost (p = 0.40). However, tumor size, lymph node status, grade, and PgR status maintained significant prognostic value by univariate analysis. Based on 40 separate studies comprising 5232 patients, the mean percentage of EGF-R positivity reported in breast cancer is 45% (range 14-91%). Nine out of 15 different studies showed in some way a significant negative association between EGF-R and RFS by univariate analysis, and 2 others showed a tendency to such a relationship. Of 7 studies applying multivariate analysis, two demonstrated an independent prognostic value of EGF-R for RFS and two others a tendency to a significant correlation, whereas three did not. It may be concluded that EGF-R status has more or less prognostic value in patients with primary breast cancer, but the prognostic power decreases with longer follow-up. Of great clinical significance is the association of EGF-R with hormone resistance. Therefore EGF-R status can be used for selection of type of treatment. Finally, EGF-R might be useful as a target for new treatment modalities.

Cell biological factors associated with the response of breast cancer to systemic treatment

A large number of cell biological parameters are currently available to predict the prognosis of patients with breast cancer, but it is still difficulty accurately to predict the response to treatment. A valuable prognostic factor can be a poor predictive factor for response, and vice versa. High tumor levels of ER, PgR, AR and pS2 predict a relatively good response to endocrine therapy, while EGF-R positively, HER2/neu positivity, aneuploidy, high proliferation indices and possibly high uPA levels indicate a high chance of poor response to endocrine therapy in metastatic breast cancer. With respect to chemotherapy, a high proliferation rate and HER2/neu amplification predict a good response to therapy in metastatic disease, while MDR gene expression and possibly c-myc amplification are related to a worse response. In conclusion, the newer cell biological parameters can be used to select high and low-risk patients, type of systemic treatment, and as targets for new treatment modalities.