J.F.R. Robertson

Prognostic markers in triple-negative breast cancer.

Triple‐negative breast cancer (estrogen receptor‐negative, progesterone receptor‐negative, and HER2‐negative) is a high risk breast cancer that lacks the benefit of specific therapy that targets these proteins.

Anastrozole Versus Tamoxifen as First-Line Therapy for Advanced Breast Cancer in 668 Postmenopausal Women: Results of the Tamoxifen or Arimidex Randomized Group Efficacy and Tolerability Study

PURPOSE To compare the efficacy and tolerability of anastrozole (Arimidex; AstraZeneca, Wilmington, DE, and Macclesfield, United Kingdom) with that of tamoxifen as first-line therapy for advanced breast cancer (ABC) in postmenopausal women. PATIENTS AND METHODS This randomized, double-blind, multicenter study evaluated the efficacy of anastrozole 1 mg once daily relative to tamoxifen 20 mg once daily in patients with tumors that were hormone receptor-positive or of unknown receptor status who were eligible for endocrine therapy. The primary end points were time to progression (TTP), objective response (OR), and tolerability. RESULTS A total of 668 patients (340 in the anastrozole arm and 328 in the tamoxifen arm) were randomized to treatment and followed-up for a median of 19 months. Median TTP was similar for both treatments (8.2 months in patients who received anastrozole and 8.3 months in patients who received tamoxifen). The tamoxifen:anastrozole hazards ratio was 0.99 (lower one-sided 95% confidence limit, 0.86), demonstrating that anastrozole was at least equivalent to tamoxifen. Anastrozole was also as effective as tamoxifen in terms of OR (32.9% of anastrozole and 32.6% of tamoxifen patients achieved a complete response [CR] or partial response [PR]). Clinical benefit (CR + PR + stabilization of > or = 24 weeks) rates were 56.2% and 55.5% for patients receiving anastrozole and tamoxifen, respectively. Both treatments were well tolerated. However, incidences of thromboembolic events and vaginal bleeding were reported in fewer patients treated with anastrozole than with tamoxifen (4.8% v 7.3% [thromboembolic events] and 1.2% v 2.4% [vaginal bleeding], respectively). CONCLUSION Anastrozole satisfied the predefined criteria for equivalence to tamoxifen. Together with the lower observed incidence of thromboembolic events and vaginal bleeding, these findings indicate that anastrozole should be considered as first-line therapy for postmenopausal women with ABC.

Fulvestrant, Formerly ICI 182,780, Is as Effective as Anastrozole in Postmenopausal Women With Advanced Breast Cancer Progressing After Prior Endocrine Treatment

PURPOSE To compare the efficacy and tolerability of fulvestrant (formerly ICI 182,780) and anastrozole in postmenopausal women with advanced breast cancer progressing after prior endocrine treatment. PATIENTS AND METHODS Patients (n = 451) with advanced breast cancer were randomized to receive fulvestrant 250 mg as a once-monthly (one x 5 mL) intramuscular injection or an oral dose of anastrozole 1 mg in this open, parallel-group, multicenter trial. The primary end point was time to progression (TTP). Secondary end points included objective response (OR) rates, defined as complete response (CR) or partial response (PR), duration of response (DOR), and tolerability. RESULTS Patients were followed for a median period of 14.4 months. In terms of TTP, fulvestrant was as effective as anastrozole (hazard ratio, 0.98; confidence interval [CI], 0.80 to 1.21; P =.84). Median TTP was 5.5 months for fulvestrant and 5.1 months for anastrozole. OR rates showed a numerical advantage for fulvestrant (20.7%) over anastrozole (15.7%) (odds ratio, 1.38; CI, 0.84 to 2.29; P =.20). Clinical benefit rates (CR + PR + stable disease > or = 24 weeks) were 44.6% for fulvestrant and 45.0% for anastrozole. Median DOR was 14.3 months for fulvestrant and 14.0 months for anastrozole. Both treatments were well tolerated, with 3.2% and 1.3% of fulvestrant- and anastrozole-treated patients, respectively, withdrawn from treatment because of an adverse event. CONCLUSION Fulvestrant was as effective as anastrozole. These data confirm that fulvestrant is an additional, effective, and well-tolerated treatment for advanced breast cancer in postmenopausal women whose disease progressed on prior endocrine therapy.

Expression of luminal and basal cytokeratins in human breast carcinoma

We have examined basal and luminal cell cytokeratin expression in 1944 cases of invasive breast carcinoma, using tissue microarray (TMA) technology, to determine the frequency of expression of each cytokeratin subtype, their relationships and prognostic relevance, if any. Expression was determined by immunocytochemistry staining using antibodies to the luminal cytokeratins (CKs) 7/8, 18 and 19 and the basal markers CK 5/6 and CK 14. Additionally, assessment of α‐smooth muscle actin (SMA) and oestrogen receptor status (ER) was performed. The vast majority of the cases showed positivity for CK 7/8, 18 and 19 indicating a differentiated glandular phenotype, a finding associated with good prognosis, ER positivity and older patient age. In contrast, basal marker expression was significantly related to poor prognosis, ER negativity and younger patient age. Multivariate analysis showed that CK 5/6 was an independent indicator for relapse free interval. We were able to subgroup the cases into four distinct phenotype categories (pure luminal, mixed luminal/basal, pure basal and null), which had significant differences in relation to the biological features and the clinical course of the disease. Tumours classified as expressing a basal phenotype (the combined luminal plus basal and the pure basal) were in a poor prognostic subgroup, typically ER negative in most cases. These findings provide further evidence that breast cancer has distinct differentiation subclasses that have both biological and clinical relevance. Copyright

High-throughput protein expression analysis using tissue microarray technology of a large well-characterised series identifies biologically distinct classes of breast cancer confirming recent cDNA expression analyses

Recent studies on gene molecular profiling using cDNA microarray in a relatively small series of breast cancer have identified biologically distinct groups with apparent clinical and prognostic relevance. The validation of such new taxonomies should be confirmed on larger series of cases prior to acceptance in clinical practice. The development of tissue microarray (TMA) technology provides methodology for high‐throughput concomitant analyses of multiple proteins on large numbers of archival tumour samples. In our study, we have used immunohistochemistry techniques applied to TMA preparations of 1,076 cases of invasive breast cancer to study the combined protein expression profiles of a large panel of well‐characterized commercially available biomarkers related to epithelial cell lineage, differentiation, hormone and growth factor receptors and gene products known to be altered in some forms of breast cancer. Using hierarchical clustering methodology, 5 groups with distinct patterns of protein expression were identified. A sixth group of only 4 cases was also identified but deemed too small for further detailed assessment. Further analysis of these clusters was performed using multiple layer perceptron (MLP)‐artificial neural network (ANN) with a back propagation algorithm to identify key biomarkers driving the membership of each group. We have identified 2 large groups by their expression of luminal epithelial cell phenotypic characteristics, hormone receptors positivity, absence of basal epithelial phenotype characteristics and lack of c‐erbB‐2 protein overexpression. Two additional groups were characterized by high c‐erbB‐2 positivity and negative or weak hormone receptors expression but showed differences in MUC1 and E‐cadherin expression. The final group was characterized by strong basal epithelial characteristics, p53 positivity, absent hormone receptors and weak to low luminal epithelial cytokeratin expression. In addition, we have identified significant differences between clusters identified in this series with respect to established prognostic factors including tumour grade, size and histologic tumour type as well as differences in patient outcomes. The different protein expression profiles identified in our study confirm the biologic heterogeneity of breast cancer and demonstrate the clinical relevance of classification in this manner. These observations could form the basis of revision of existing traditional classification systems for breast cancer.

Anastrozole Is Superior to Tamoxifen as First-Line Therapy in Hormone Receptor Positive Advanced Breast Carcinoma Results of Two Randomized Trials Designed for Combined Analysis

BACKGROUND Two randomized, double-blind trials have compared tamoxifen 20 mg daily and the selective, nonsteroidal aromatase inhibitor anastrozole 1 mg daily as first-line therapy for advanced breast carcinoma (ABC) in postmenopausal women. The trials were prospectively designed to allow for combined data analyses. METHODS The combined study population included 1021 postmenopausal women (median age, 67 years [range, 30–92]) with ABC whose tumors were either estrogen and/or progesterone receptor positive or of unknown receptor status. Primary endpoints were time to progression (TTP), objective response, and tolerability. RESULTS At a median duration of follow-up of 18.2 months, anastrozole was at least equivalent to tamoxifen in terms of median TTP (8.5 and 7.0 months, respectively; estimated hazard ratio [tamoxifen relative to anastrozole], 1.13 [lower 95% confidence level, 1.00]). In a retrospective subgroup analysis, anastrozole was superior to tamoxifen with respect to TTP (median values of 10.7 and 6.4 months for anastrozole and tamoxifen, respectively, two-sided P = 0.022) in patients with estrogen and/or progesterone receptor positive tumors (60% of combined trial population). In terms of objective response, 29.0% of anastrozole and 27.1% of tamoxifen patients achieved either a complete response (CR) or a partial response (PR). Clinical benefit (CR + PR + stabilization of ≥ 24 weeks) rates were 57.1% and 52.0% for anastrozole and tamoxifen, respectively. Both anastrozole and tamoxifen were well tolerated. Anastrozole led to significantly fewer venous thromboembolic (P = 0.043; not adjusted for multiple comparisons) events, and vaginal bleeding was reported in fewer patients treated with anastrozole than with tamoxifen. CONCLUSIONS In postmenopausal women with hormonally sensitive ABC, anastrozole should be considered as the new standard first-line treatment. Cancer 2001;92:2247–58.

Double-Blind, Randomized Placebo Controlled Trial of Fulvestrant Compared With Exemestane After Prior Nonsteroidal Aromatase Inhibitor Therapy in Postmenopausal Women With Hormone Receptor–Positive, Advanced Breast Cancer: Results From EFECT

PURPOSE The third-generation nonsteroidal aromatase inhibitors (AIs) are increasingly used as adjuvant and first-line advanced therapy for postmenopausal, hormone receptor-positive (HR+) breast cancer. Because many patients subsequently experience progression or relapse, it is important to identify agents with efficacy after AI failure. MATERIALS AND METHODS Evaluation of Faslodex versus Exemestane Clinical Trial (EFECT) is a randomized, double-blind, placebo controlled, multicenter phase III trial of fulvestrant versus exemestane in postmenopausal women with HR+ advanced breast cancer (ABC) progressing or recurring after nonsteroidal AI. The primary end point was time to progression (TTP). A fulvestrant loading-dose (LD) regimen was used: 500 mg intramuscularly on day 0, 250 mg on days 14, 28, and 250 mg every 28 days thereafter. Exemestane 25 mg orally was administered once daily. RESULTS A total of 693 women were randomly assigned to fulvestrant (n = 351) or exemestane (n = 342). Approximately 60% of patients had received at least two prior endocrine therapies. Median TTP was 3.7 months in both groups (hazard ratio = 0.963; 95% CI, 0.819 to 1.133; P = .6531). The overall response rate (7.4% v 6.7%; P = .736) and clinical benefit rate (32.2% v 31.5%; P = .853) were similar between fulvestrant and exemestane respectively. Median duration of clinical benefit was 9.3 and 8.3 months, respectively. Both treatments were well tolerated, with no significant differences in the incidence of adverse events or quality of life. Pharmacokinetic data confirm that steady-state was reached within 1 month with the LD schedule of fulvestrant. CONCLUSION Fulvestrant LD and exemestane are equally active and well-tolerated in a meaningful proportion of postmenopausal women with ABC who have experienced progression or recurrence during treatment with a nonsteroidal AI.

Response to a specific antioestrogen (ICI 182780) in tamoxifen-resistant breast cancer

We treated 19 patients with advanced breast cancer resistant to tamoxifen with a new specific antioestrogen (ICI 182780) which, in animal studies, has no agonist activity. 13 (69%) patients responded (7 had partial responses and 6 showed no change) to monthly intramuscular injections of ICI 182780 after progression on tamoxifen, for a median duration of 18 months with minimum side effects. Preliminary evidence suggests that the agent is without effects on the liver or the hypothalamic-pituitary axis. ICI 182780 appears to be a promising new agent for treatment of advanced and early breast cancer.

Morphological and immunophenotypic analysis of breast carcinomas with basal and myoepithelial differentiation

The aim of this study was to assess the morphological characteristics and immunohistochemical profile of breast carcinomas with basal and myoepithelial phenotypes to obtain a better understanding of their biological behaviour and nature. One thousand nine hundred and forty‐four invasive breast carcinomas were examined, using tissue microarray (TMA) technology and immunohistochemistry, to identify those tumours that showed basal and myoepithelial phenotypes, and their immunophenotype profile was characterized using a variety of markers. In addition, haematoxylin and eosin‐stained sections of these tumours were studied for several morphological parameters. The findings were correlated with patient and tumour characteristics and outcome data. Tumours were classified into two groups: (1) tumours with basal phenotype [expressing one or both basal markers (CK5/6 and/or CK14)] and (2) tumours with myoepithelial phenotype (expressing SMA and/or p63). Group 1 was further subdivided into two subgroups: (A) dominant basal pattern (more than 50% of cells positive) and (B) basal characteristics (10–50% of cells positive). Group 1 tumours constituted 18.6% (8.6% and 10% for groups 1A and 1B, respectively) and group 2 constituted 13.7% of the cases. In both groups, the most common histological types were ductal/no specific type, tubular mixed and medullary‐like carcinomas; the majority of these tumours were grade 3. There were positive associations with adenoid cystic growth pattern, loss of tubule formation, marked cellular pleomorphism, poorer Nottingham prognostic index, and development of distant metastasis. In addition, associations were found with loss of expression of steroid hormone receptors and FHIT proteins and positive expression of p53 and EGFR. The most common characteristics in group 1 were larger size, high‐grade comedo‐type necrosis, development of tumour recurrence, and absence of lymph node disease. Group 2 tumours were more common in younger patients and were associated with central acellular zones, basaloid change, and positive E‐cadherin protein expression. Group 1 characteristics were associated with both reduced overall survival (OS) [log rank (LR) = 22.5, p < 0.001] and reduced disease‐free interval (DFI) (LR = 30.1, p < 0.001), while group 2 characteristics showed an association with OS (LR = 5, p = 0.02) but not with DFI. Multivariate analysis showed that basal, but not myoepithelial, phenotype has an independent value in predicting outcome. Breast cancers with basal and myoepithelial phenotypes are distinct groups of tumours that share some common morphological features and an association with poor prognosis. The basal rather than the myoepithelial phenotype has the strongest relationship with patient outcome. Copyright

Fulvestrant versus anastrozole for the treatment of advanced breast carcinoma in postmenopausal women: A prospective combined analysis of two multicenter trials

Fulvestrant (ICI 182,780) is a new type of estrogen receptor (ER) antagonist that down‐regulates the ER and has no known agonist effects. The authors report the prospectively planned combined analysis of data from 2 Phase III trials comparing fulvestrant 250 mg monthly (n = 428) and anastrozole 1 mg daily (n = 423) in postmenopausal women with advanced breast carcinoma (ABC) who previously had progressed after receiving endocrine treatment.