Distribution of estrogen and progesterone receptors in primary tumor and lymph nodes in individual patients with breast cancer

Primary breast cancer tissue and lymph nodes were obtained from 48 patients. Estrogen receptors (ER) and progesterone receptors (PgR) were determined by a dextran-coated charcoal assay. ER were present in 72.9% of the primary tumors and in 62.4% of the malignant lymph nodes, whereas PgR were present in 73.0% and 50.0% of the cases, respectively. The primary tumor and the corresponding malignant lymph nodes showed an identical ER and PgR status, i.e., both tumor sites were receptor positive or both receptor negative in 89.6% and 77.1%, respectively. However, 10.4% of the patients had ER-positive tumors but ER-negative lymph nodes and 22.9% had PgR-positive primaries with PgR-negative lymph nodes. No receptor-positive lymph nodes showed a combination with receptor-negative primary tumor. This preliminary data shows that receptor-positive malignant lymph nodes mostly display the same receptor status as the corresponding primary tumor, whereas receptor-negative lymph nodes may have a receptor-positive primary tumor.     

Prognostic significance of progesterone receptor levels in estrogen receptor-positive patients with metastatic breast cancer treated with tamoxifen: results of a prospective Southwest Oncology Group study.

PURPOSE: Southwest Oncology Group (SWOG) protocol 8228 is a prospective trial designed to investigate the prognostic significance of progesterone receptor (PgR) levels in estrogen receptor (ER)-positive breast cancer patients who were treated with tamoxifen. This study was undertaken because the value of PgR measurements in advanced breast cancer had been assessed previously only in studies that were small, retrospective, or included heterogeneously treated patients. METHODS: Receptor assays were performed only in the laboratories that met strict quality control guidelines. Of the 398 patients entered, 342 patients were eligible and assessable for the study end points of objective clinical response, time to treatment failure, and overall survival. RESULTS: Multivariate analysis shows that elevated PgR levels significantly and independently correlated with increased probability of response to tamoxifen, longer time to treatment failure, and longer overall survival. Overall response rate (defined as complete response [CR], partial response [PR], or stable disease [SD] for greater than 6 months) in this trial was 54%. Response rates to tamoxifen were 43%, 53%, and 61% in subsets of patients with less than 10, 10 to 99, and more than 100 fmol/mg PgR, respectively. Exploratory subset analysis using PgR and other prognostic variables identified ER-positive patient subsets with response rates to tamoxifen ranging from 24% (premenopausal patients) to 86% (postmenopausal patients with ER greater than 38 and PgR greater than 329 fmol/mg). No groups of ER-positive patients were identified who had such a low response rate as to absolutely preclude considering the use of tamoxifen. Multivariate analysis showed the independent, statistically significant predictors were: for response to tamoxifen, menopausal status, PgR, and ER; for time to treatment failure, menopausal status, disease-free interval (DFI), PgR, and ER; and for overall survival DFI, PgR, ER, site of disease, and history of adjuvant therapy. CONCLUSION: We conclude that knowledge of PgR levels together with other clinical information can improve the pretreatment assessment of ER-positive breast cancer patients with metastatic disease.     

Hormone receptor status of a contralateral breast cancer is independent of the receptor status of the first primary in patients not receiving adjuvant tamoxifen.

PURPOSE: To determine whether the hormone receptor status of the primary breast cancer (PBC) is predictive of the hormone receptor status of the subsequent contralateral breast cancer (CBC). PATIENTS AND METHODS: We identified patients in our database with known estrogen receptor (ER; n = 193) and/or progesterone receptor (PgR; n = 178) status in their PBC and in their subsequent CBC. One hundred twenty-six of these patients had received no adjuvant therapy, 34 had received adjuvant tamoxifen, and 33 had received adjuvant chemotherapy alone. The median interval between the first diagnosis of PBC and the development of the subsequent CBC was 3 years. ER and PgR assays were assessed biochemically in two central reference laboratories using identical quality-controlled ligand-binding methods. RESULTS: Among systemically untreated patients (n = 126), 88% of patients with ER-positive PBC and 75% of patients with ER-negative PBC developed an ER-positive CBC (P = .11). Among the tamoxifen-treated patients, those with an ER-positive PBC were almost equally likely to develop an ER-positive (47%) or ER-negative (53%) CBC (P = .99). PgR status was similar. In the untreated group (n = 112), 59% of patients with a PgR-positive PBC and 66% with a PgR-negative PBC developed a PgR-positive CBC (P = .48). Among tamoxifen-treated patients (n = 33), 50% of patients with a PgR-positive PBC versus 27% of patients with a PgR-negative PBC developed a PgR-positive CBC (P = .28). CONCLUSION: ER and PgR status of the primary tumor does not predict the hormone receptor status of the subsequent CBC in the absence of selective pressure of adjuvant therapy. Thus, other reasons should be considered to clarify the failure of tamoxifen to reduce the incidence of CBC in patients with a receptor-negative PBC.     

Estrogen and progesterone receptors as prognostic factors in breast cancer

The relation between estrogen receptors (ER) and/or progesterone receptors (PgR) and some clinical factors such as tumor size, axillary node involvement, histological tumor grade, and disease-free interval (DFI) in 500 patients with operable (TNM stage I-III) breast cancer was studied. ER-positive (ER+) tumors were commoner in older patients, whereas PgR-positive (PgR+) tumors were similarly distributed within the age groups. The concentration of ER+ protein also increased with age in contrast to PgR+ protein concentration. However, receptor status was not associated with menopausal status independently of age. Axillary node involvement influenced neither ER nor PgR status, but there was a statistically significant relation between tumor size and positivity of ER or PgR. There was no association between histologic tumor grade and either steroid receptor phenotype. DFI was longer in patients with ER+ than those with ER- tumors, independently of axillary nodal status. The positivity of PgR in patients with ER+ tumors contributed to an even longer DFI, suggesting that the combination of ER/PgR is a better indicator of DFI than ER or PgR alone.     

Progesterone receptor status significantly improves outcome prediction over estrogen receptor status alone for adjuvant endocrine therapy in two large breast cancer databases.

PURPOSE: To determine whether progesterone receptor (PgR) status provides additional value to estrogen receptor (ER) status and improves prediction of benefit from endocrine treatment among patients with primary breast cancer. PATIENTS AND METHODS: Clinical outcomes of patients in two large databases were analyzed as a function of steroid receptor status. The first database (PP), contained 3,739 patients who did not receive any systemic adjuvant therapy and 1,688 patients who received adjuvant endocrine therapy but no chemotherapy. The second database (SPORE), contained 10,444 patients who received adjuvant endocrine therapy but no chemotherapy. Biochemical ER and PgR assays were identically performed in two different central laboratories. RESULTS: In univariate and multivariate analyses, the prognostic significance of PgR status among systemically untreated patients is modest. Among endocrine-treated patients, however, multivariate analyses, including lymph-node involvement, tumor size, and age, demonstrate that PgR status is independently associated with disease-free and overall survival. For recurrence, the reduction in relative risk (RR) was 25% for ER-positive/PgR-negative patients and 53% for ER-positive/PgR-positive patients, compared with ER-negative/PgR-negative patients (P <.0001, PP patients). Patients with ER-positive/PgR-negative tumors have a reduction in RR of death of 30% (SPORE patients) and 38% (PP patients), compared with patients with ER-negative/PgR-negative tumors (P <.0001). For ER-positive/PgR-positive tumors, the reduction of the risk of death was greater than 46% in SPORE patients and 58% in PP patients, indicating that ER-positive/PgR-positive patients derive more benefit from endocrine therapy (P <.0001). CONCLUSION: When accurately measured, PgR status is an independent predictive factor for benefit from adjuvant endocrine therapy. Therefore, PgR status should be taken into account when discussing RR reductions expected from endocrine treatment with individual patients.     

Benefit from adjuvant tamoxifen therapy in primary breast cancer patients according oestrogen receptor, progesterone receptor, EGF receptor and HER2 status.

BACKGROUND: Most women with oestrogen receptor (ER) positive primary breast cancer receive adjuvant tamoxifen after surgery. The measurement of tumour biomarkers should allow better selection of patients for such treatment or for therapies such as aromatase inhibitors. PATIENTS AND METHODS: Histopathological blocks of primary breast cancer patients who had been randomized to receive 2-years tamoxifen or no adjuvant therapy in two mature randomised clinical trials were retrieved. Immunohistochemical staining for ER, progesterone receptor (PgR), HER2 and epidermal growth factor receptor (EGFR) was undertaken. The primary endpoint was relapse free survival. RESULTS: 813 patients were included in the study. Benefit from tamoxifen was seen in ER-positive patients [Relative risk (rr) 0.77, ci 0.63-0.93]. ER-negative patients also showed a strong trend to benefit from tamoxifen (rr 0.73, ci 0.52-1.02) which was largely confined to the PgR-positive group. Amongst the ER-positive group, PgR-positive and PgR-negative patients showed similar benefit (rr 0.81; ci 0.65-1.02 and 0.70; ci 0.49-0.99, respectively). Patients positive for HER2 did not benefit significantly (rr 1.14; ci 0.75-1.73) but this group was small. CONCLUSIONS: Measurement of PgR status in ER-negative patients defines a group of patients that benefit from tamoxifen but would be excluded from tamoxifen therapy on the basis of ER status alone. The data are consistent with HER2 positive tumours being resistant to tamoxifen.     

Relationship of PS2 with response to tamoxifen therapy in patients with recurrent breast cancer.

PS2, an oestrogen-inducible protein, was measured in the cytosol of 230 primary tumours from patients who were subjected to first-line tamoxifen therapy for advanced disease without prior adjuvant therapy with tamoxifen. PS2 correlated positively with oestrogen receptor (ER, P < 0.01) and progesterone receptor content (PgR, P < 0.001), and with the length of progression-free survival (PFS, P = 0.05). Although not statistically significant, higher levels of PS2 (> or = 10 ng mg-1 protein) were also associated with increased probability of response to tamoxifen treatment and a longer total post-relapse survival (PRS). ER, PgR, menopausal status, site of disease and prior adjuvant chemotherapy were all associated with response to tamoxifen therapy and with PFS. In multivariate analysis for PFS, low levels of ER and PgR, visceral metastasis, a disease-free interval of less than 1 year and prior adjuvant chemotherapy were all significantly associated with an increased probability of a rapid disease progression after start of tamoxifen therapy. In the subset of 83 tumours with intermediate levels of ER and PgR (both > or = 10, but not both > or = 75 fmol mg-1 protein), PS2 was positively related with the length of PFS (P < 0.01) and PRS (P < 0.05). PS2 remained the strongest factor in multivariate analysis for PFS (P < 0.01) in this ER/PgR intermediate subgroup, but was not of predictive value in univariate or multivariate analysis for both PFS and PRS in tumours classified as ER/PgR low or high (> or = 75 fmol mg-1 protein). It is concluded that PS2 status may be used as a parameter, additional to ER and PgR, for better refinement of prediction of response to tamoxifen treatment in advanced breast cancer patients especially with intermediate ER/PgR levels in their primary tumour.     

Human breast cancer: survival from first metastasis

Summary Survival from the detection of first metastasis (SAM) was analyzed in a single center series of 258 patients with advanced breast cancer. During the 15 year period covered by this study 230 patients died, 215 of their disease. The overall median SAM was 28 months.Univariate analysis of SAM stratified by first dominant site of metastasis, estrogen receptor status (ER), progesterone receptor status (PgR), tumor size, axillary lymph node status, patient age, menopausal status, and disease-free interval (DFI) showed the first dominant site of metastasis, ER, PgR, and axillary lymph node status to be significantly associated with SAM. Patients with visceral metastasis as first dominant site of metastasis had significantly shorter survival than those with either bone or soft tissue metastasis, median SAM 16 vs. 34 vs. 41 months respectively (P<0.001). SAM also differed according to the steroid hormone receptor status of the primary tumor: median SAM 34 and 33 months for patients with ER-positive or patients with PgR-positive tumors against 14 months for patients with ER-negative or with PgR-negative tumors (P<0.001). Patients with axillary lymph node involvement at primary disease had a shorter SAM than those without, median SAM 24 vs. 35 months (P=0.006). No association between SAM and either tumor size, patient age, menopausal status, or DFI could be observed.Multivariate analysis including first dominant site of metastasis, ER, PgR, and axillary lymph node status showed the first dominant site of metastasis, ER, and axillary lymph node status to be independently associated with SAM.including the Departments of Surgery (Th. Wobbes, R.F. v.d. Sluis), Radiotherapy (W.A.J. v. Daal), Pathology (R. Holland), Radiology (J.H.C.L. Hendriks) and Medical Oncology (D. Wagener)     

Tumor-proliferative activity, progesterone receptor status, estrogen receptor level, and clinical outcome of estrogen receptor-positive advanced breast cancer

The relations among pretreatment tumor-proliferative activity, progesterone receptor (PgR) status, estrogen receptor (ER) level, and clinical outcome were analyzed in a series of 45 ER-positive advanced breast cancer postmenopausal women treated with tamoxifen (20 mg/day) until disease progression. Tritiated thymidine ([3H]dThd) Labeling Index (LI) by autoradiographic assay was utilized for proliferative activity analysis, whereas the dextran-coated charcoal method was used for ER and PgR evaluation (cutoff value, 10 fmol/mg of protein cytosol). The median [3H]dThd LI value was 1.8%; 73% of cases were PgR positive, and 53% were highly ER positive (greater than 100 fmol/mg of protein cytosol). Clinical responses were more frequently observed in slowly than in quickly proliferating tumors (86% versus 60%; P less than 0.05) but were similar for PgR-positive and -negative cases, as well as for those with high and low ER positivity. Only [3H]dThd LI was found to individualize patients with different survival rates (at 40 mo of follow-up, 78% versus 40% in slowly and quickly proliferating tumors, respectively). The [3H]dThd LI, monitored in ten patients by a second tumor biopsy after 14 days of tamoxifen therapy, was found to have a significantly lower median value (P = 0.03). These data indicate that pretreatment [3H]dThd LI provides information, which is not available in a study of PgR and ER status, on the clinical outcome of ER-positive advanced breast cancer patients treated by hormone therapy.     

Steroid hormone receptor activity of primary human breast cancer and pattern of first metastasis

Summary A series of 258 breast cancer patients with known estrogen receptor (ER) status of the primary tumour who subsequently developed metastases were reviewed for site of first metastasis. In 188 cases progesterone receptor (PgR) data were also available.Univariate analysis showed metastatic patterns to differ statistically significantly related to ER status and (less pronounced) PgR status of the primary tumour. Patients with ER-positive tumours had bone metastases three times more often than patients with ER-negative tumours. With respect to PgR-positive and PgR-negative tumours this frequency differed by a factor of two. With regard to visceral metastases ER and PgR status were equally potent prognosticators, patients with receptor negative tumours having a 50% higher frequency of visceral metastasis than patients with receptor positive tumours. Assessment of metastatic patterns in relation to combined receptor status did not substantially enhance the discriminatory value of ER and PgR when assessed separately.Multivariate analysis showed that the observed differences in metastatic patterns were all attributable to differences in the ER status of the primary tumour, and were not influenced by age, menopausal status, axillary lymph node involvement, duration of disease-free interval (DFI), mode of postoperative treatment, or the PgR status of the primary tumour.Including the Departments of Surgery (Th. Wobbes, R.F. v.d. Sluis), Radiotherapy (W.A.J. v. Daal), Pathology (R. Holland), Radiology (J.H.C.L. Hendriks), and Medical Oncology (D. Wagener)     

Prognostic value of hormone receptors in breast cancer

The aim of this study was to establish the role of estrogen receptor (ER) and progesterone receptor (PgR) as prognostic indicators for early recurrence and survival. In all, among breast cancer patients, 166 patients who had undergone radical or extended radical mastectomy were studied. These patients were treated with adjuvant chemotherapy alone for 2-3 years after surgery. No patients had adjuvant endocrine therapy. Local recurrence and/or distant metastases were treated by endocrine therapy and/or chemotherapy. The relapse-free interval was not different between the ER-positive and ER-negative patients. The postrelapse survival curve was significantly different between the two groups. There was no significant difference in the relapse-free interval and the postrelapse survival curve between the PgR-positive and PgR-negative patients. These results suggest that ER is a good predictor of the response to endocrine therapy given after relapse, but not of early recurrence.     

pS2 expression and response to hormonal therapy in patients with advanced breast cancer

Seventy-two patients with advanced breast carcinoma (42% bone, 25% visceral, 5.5% soft tissue, and 27.5% multiple site metastases) were evaluated to determine the relationship between tumor expression of the estrogen-regulated protein pS2, estrogen receptor (ER) or progesterone receptor (PgR) content, and response to hormonal therapy. Twenty-nine % of tumors were pS2 positive, 64% were ER positive, and 29% were PgR positive. Of the ER-positive patients (n = 43), 15 (35%) had greater than 10% of the invasive carcinoma which immunostained for pS2 (these were considered pS2 positive). Only 3 of 24 ER-negative tumors were pS2 positive. A weak association between pS2 expression and ER content (P = 0.08) but not PgR content was observed. Of pS2-positive patients, 52% had a partial or complete response to hormonal therapy. In 24% of pS2-positive patients the disease stabilized with treatment. In contrast, 27% of pS2-negative patients had a partial or complete response. In 10% of these patients the disease stabilized. Similar associations between therapeutic response and ER or PgR were not observed. The odds of having a clinical response to hormonal therapy was greater for pS2-positive than for ER- or PgR-positive tumors. pS2 expression may define a subset of ER-positive tumors that are more likely to respond to hormonal treatment.     

Progesterone receptor loss identifies Luminal B breast cancer subgroups at higher risk of relapse

BackgroundThe immunohistochemical (IHC) evaluation of estrogen receptor (ER), progesterone receptor (PgR), Ki-67 and HER2 is considered a surrogate means for identifying the molecular subtypes of breast cancer with different prognosis.Patients and methodsWe explored patterns of recurrence in 4837 women with breast cancer defined as Luminal B (ER-positive and/or PgR-positive, HER2 positive and/or Ki-67≥14%) by IHC classification. We evaluated four subgroups within the Luminal B subtype according to HER2 expression and PgR status.ResultsPatients within the ER+/PgR+/HER2- subgroup presented a 5-year breast cancer-related survival (BCS) of 97% (95% confidence interval (CI), 96–97) and overall survival (OS) of 95% [95% CI, 95–96], the best survivals of the Luminal B subgroups. In the multivariate analysis, the ER+/PgR-/HER2- subgroup was associated with a reduced BCS (HR 1.71; 95%CI, 1.25–2.35) and OS (HR 1.47; 95%CI, 1.10–1.96) when compared with the ER+/PgR+/HER2- subgroup. Also patients within the ER+/PgR-/HER2+ subgroup had a reduced BCS (HR 1.93; 95%CI, 1.32–2.83) and OS (HR 1.62; 95%CI, 1.14–2.30) when compared with ER+/PgR+/HER2- subgroup. On the other hand, no statistically significant differences were found with regard to BCS and OS among patients with ER+/PgR+/HER2+ and patients with ER+/PgR+/HER2- disease.ConclusionsPgR loss identifies Luminal B breast cancer subgroups at higher risk of relapse and death, both with HER-2-positive and HER-2-negative disease.     

Prognostic value of steroid hormone receptors: multivariate analysis of systemically untreated patients with node negative primary breast cancer

The value of estrogen and progesterone receptor (ER and PgR, respectively) determinations in predicting the recurrence-free survival (RFS) has been evaluated in a group of 807 node negative breast cancer patients. All of these patients are enrolled in the Danish Breast Cancer Cooperative Group (DBCG) 77-1a and 82-a protocols for low risk patients, and none of them have received systemic adjuvant therapy. At a median observation time of 50 months and in an evaluation of the total patient population as an entity, ER+ patients had only a marginally significant (P = 0.07) longer RFS than ER- patients while PgR+ patients experienced a significant advantage (P = 0.02). Among patients subgrouped according to menopausal status, both ER and PgR statuses were found to be significant prognostic factors for predicting RFS in the premenopausal women (less than 50 years) but not in peri- or postmenopausal women. Using Cox's multivariate analysis, nuclear pleomorphy was found to be the only significant prognostic variable, while the value of PgR status as a prognostic factor approached significance (P = 0.065). Although knowledge of ER status did not significantly improve distinction between patients with good and poor prognoses in the relatively small subgroup of premenopausal patients (n = 120) when PgR status was known, ER+PgR- patients have a lower risk of recurrence or death than ER-PgR- patients. Using a log-likelihood model, significant and distinct cut-off limits for the definition of receptor positivity were found for premenopausal patients: these were 5 fmol/mg cytosol protein for ER and 10 fmol/mg cytosol protein for PgR. These cut-off levels may reflect the ability of the ligand binding assay method used to discriminate between tissues with and without receptor proteins. Qualitative assessment of receptor status was as valuable as quantitative expression of receptor concentrations in predicting the RFS of the natural course of the disease among node negative premenopausal patients.     

Low number of examined lymph nodes in node-negative breast cancer patients is an adverse prognostic factor.

BACKGROUND: The aim of the study was to determine whether the number of lymph nodes removed at axillary dissection is associated with recurrence and survival in node-negative breast cancer (NNBC) patients. PATIENTS AND METHODS: We retrospectively reviewed the medical records of 1606 women with pathologically node-negative T1-T3 invasive breast cancer. Median follow-up was 61 months (range 2-251). Potential prognostic factors assessed included: number of axillary lymph nodes examined, age, menopausal status, tumor size, histological type, tumor grade, estrogen receptor(ER), progesterone receptor (PR) and HER2. RESULTS: At 5 years, relapse-free survival (RFS) rate was 85% and breast cancer-specific survival (BCSS) rate was 94%. In univariate analysis, factors significantly associated with lower RFS and BCSS were: fewer than six lymph nodes examined (RFS, P = 0.01; BCSS, P = 0.007), tumor size >2 cm, grade III, negative ER or PR. Statistically significant factors for lower RFS and BCSS in multivariate analysis were: fewer than six lymph nodes examined [RFS, hazard ratio (HR) 1.36, P = 0.029; BCSS, HR 1.87, P = 0.005], tumor size >2 cm, tumor grade III and negative PR. CONCLUSIONS: Examination of fewer than six lymph nodes is an adverse prognostic factor in NNBC because it could lead to understaging. Six or more nodes need to be examined at axillary dissection to be confident of a node-negative status. This may be useful, in conjunction with other prognostic factors, in the assessment of NNBC patients for adjuvant systemic therapy.     

Lack of G protein-coupled estrogen receptor (GPER) in the plasma membrane is associated with excellent long-term prognosis in breast cancer

G protein-coupled estrogen receptor (GPER), or GPR30, is a membrane receptor reported to mediate non-genomic estrogen responses. Tamoxifen is a partial agonist at GPER in vitro. Here, we investigated if GPER expression is prognostic in primary breast cancer, if the receptor is treatment-predictive for adjuvant tamoxifen, and if receptor subcellular localization has any impact on the prognostic value. Total and plasma membrane (PM) GPER expression was analyzed by immunohistochemistry in breast tumors from 742 postmenopausal lymph node-negative patients subsequently randomized for tamoxifen treatment for 2–5 years versus no systemic treatment, regardless of estrogen receptor (ER) status, and with a median follow-up of 17 years for patients free of event. PM GPER expression was a strong independent prognostic factor for poor prognosis in breast cancer without treatment-predictive information for tamoxifen. In the tamoxifen-treated ER-positive and progesterone receptor (PgR)-positive patient subgroup, the absence of PM GPER (53 % of all ER-positive tumors) predicted 91 % 20-year distant disease-free survival, compared to 73 % in the presence of GPER (p = 0.001). Total GPER expression showed positive correlations with ER and PgR and negative correlation with histological grade, but the correlations were biphasic. On the other hand, PM GPER expression showed strong negative correlations with ER and PgR, and strong positive correlation with HER2 overexpression and high histological grade. GPER overexpression and PM localization are critical events in breast cancer progression, and lack of GPER in the PM is associated with excellent long-term prognosis in ER-positive and PgR-positive tamoxifen-treated primary breast cancer.     

Phosphorylated c-Src in the nucleus is associated with improved patient outcome in ER-positive breast cancer

Elevated c-Src protein expression has been shown in breast cancer and in vitro evidence suggests a role in endocrine resistance. To investigate whether c-Src is involved in endocrine resistance, we examined the expression of both total and activated c-Src in human breast cancer specimens from a cohort of oestrogen receptor (ER)-positive tamoxifen-treated breast cancer patients. Tissue microarray technology was employed to analyse 262 tumour specimens taken before tamoxifen treatment. Immunohistochemistry using total c-Src and activated c-Src antibodies was performed. Kaplan–Meier survival curves were constructed and log-rank test were performed. High level of nuclear activated Src was significantly associated with improved overall survival (P=0.047) and lower recurrence rates on tamoxifen (P=0.02). Improved patient outcome was only seen with activated Src in the nucleus. Nuclear activated Src expression was significantly associated with node-negative disease and a lower NPI (P<0.05). On subgroup analysis, only ER-positive/progesterone receptor (PgR)-positive tumours were associated with improved survival (P=0.004). This shows that c-Src activity is increased in breast cancer and that activated Src within the nucleus of ER-positive tumours predicts an improved outcome. In ER/PgR-positive disease, activated Src kinase does not appear to be involved in de novo endocrine resistance. Further study is required in ER-negative breast cancer as this may represent a cohort in which it is associated with poor outcome.     

Estrogen Receptor Mutations and Changes in Estrogen Receptor and Progesterone Receptor Protein Expression in Metastatic or Recurrent Breast Cancer

To investigate the frequency of estrogen receptor ( ER ) gene mutation in metastatic or recurrent breast cancer, metastatic lymph nodes or recurrent breast cancer tissue from 35 patients with ER-positive primary tumors were screened for mutations in the hormone-binding domain of the ER gene by sequence analysis. Four missense mutations, Val316Ile, Gly344Val, Ala430Val and Gly494Val, were identified in these lesions. Second, to clarify whether there is any disparity in hormone receptor status between primary and metastatic or recurrent tumors, we immunohistochemically studied 117 specimens including the above 35 specimens obtained from metastatic or recurrent breast cancer patients using monoclonal anti-ER and progesterone receptor (PgR) antibodies. Although hormone receptor status, especially ER, was highly maintained through disease progression, negative change in PgR expression at relapse (33%) was identified more frequently than in metastatic lymph nodes (6.7%). Therefore, it was suggested that development of PgR-negative phenotype might correlate with disease progression in some breast cancer patients. These results suggest that ER mutations in metastatic or recurrent breast cancer may be more frequent than in primary lesions, irrespective of high maintenance of ER protein expression through disease progression.     

The predictive value of estrogen and progesterone receptors' concentrations on the clinical behavior of breast cancer in women. Clinical correlation on 547 patients

The aims of this study were as follows: to confirm that the presence of estrogen (ER) and progesterone (PgR) receptors is an indicator of clinical behavior of human breast cancer independent of other known prognostic factors; to seek clinical correlates of those receptor values that best predict the overall disease evolution; and to determine the relative prognostic importance of PgR versus ER. The clinical records of 547 patients, the follow-up of some extending to 6 years, were analyzed in retrospect. Patients were placed into one of four disease stages and also in three groups according to the degree of axillary node involvement. In each group the prognostic value of receptors for patient survival, disease-free interval and, in case of metastasis or local recurrence, the response to endocrine treatment or chemotherapy were studied. The break point in the spectrum of receptor concentrations with regard to survival, disease-free interval, and response to treatment was greater than or equal to 20 for ER+, greater than or equal to 15 for PgR+, and less than 5 for both ER- and PgR- reported in fmol/mg protein. Survival and disease-free interval showed positive correlations with ER and PgR (P less than 0.001-less than 0.0003). When disease stage or node involvement were considered, these correlations were found essentially in Stage II and node involvement in more than three nodes, where patients had longer survival and disease-free interval if ER and PgR were positive (P less than 0.05-less than 0.0003). Estrogen receptor was a more sensitive prognostic indicator than PgR, and the combination ER+/PgR+ showed a correlation equivalent to ER+/PgR-. The correct prediction percentages of the response of patients to endocrine treatment were 77% if ER+, 69% if PgR+, and 79% if both ER+ and PgR+. However, the correct prediction percentage of the response to chemotherapy was of 50%. These results show that ER and PgR are prognostic factors for survival and disease-free interval mainly on patients at Stage II and node involvement of greater than three, with ER demonstrating a better predictive value than PgR. The measurement of these receptors provides a prognostic index for response to endocrine therapy but is without value in predicting the response to chemotherapy.     

Progesterone receptor activity and relapse-free survival in patients with primary breast cancer: The role of adjuvant chemotherapy

The prognostic significance of progesterone receptor activity (PgR) with regard to the estimated relapse-free survival (RFS) was studied in 350 one-center patients with primary breast cancer. All receptor assays were performed in one laboratory; PgR levels >10 fmol/mg protein were considered positive. Univariate as well as multivariate statistical analyses were used to examine the prognostic significance of several variables. Eighty-nine of the 350 patients received adjuvant CMF chemotherapy (cyclophosphamide, methotrexate, and 5-fluorouracil). The median observation period was 69 months (range 12–125 months).In the group of 261 patients who did not receive adjuvant CMF, the PgR-status lacked prognostic significance; only the lymph node status significantly affected the RFS (p<0.00001). In contrast, in the CMF-treated group of patients, the PgR-status was the most powerful predictor of recurrence (p<0.0001). The menopausal and the lymph-node status increased the predictive value of PgR (p<0.001). Premenopausal CMF-treated patients with PgR⁺ tumors had a significantly longer RFS than those with PgR^– tumors (p<0.02). The present data urge the need for a reappraisal of the prognostic significance of PgR and of the mechanism of action of adjuvant chemotherapy in primary breast cancer.