Louk V.A.M. Beex

Multicenter Validation of a Gene Expression–Based Prognostic Signature in Lymph Node–Negative Primary Breast Cancer

PURPOSE We previously identified in a single-center study a 76-gene prognostic signature for lymph node-negative (LNN) breast cancer patients. The aim of this study was to validate this gene signature in an independent more diverse population of LNN patients from multiple institutions. PATIENTS AND METHODS Using custom-designed DNA chips we analyzed the expression of the 76 genes in RNA of frozen tumor samples from 180 LNN patients who did not receive adjuvant systemic treatment. RESULTS In this independent validation, the 76-gene signature was highly informative in identifying patients with distant metastasis within 5 years (hazard ratio, [HR], 7.41; 95% CI, 2.63 to 20.9), even when corrected for traditional prognostic factors in multivariate analysis (HR, 11.36; 95% CI, 2.67 to 48.4). The actuarial 5- and 10-year distant metastasis-free survival were 96% (95% CI, 89% to 99%) and 94% (95% CI, 83% to 98%), respectively, for the good profile group and 74% (95% CI, 64% to 81%) and 65% (53% to 74%), respectively for the poor profile group. The sensitivity for 5-yr distant metastasis-free survival was 90%, and the specificity was 50%. The positive and negative predictive values were 38% (95% CI, 29% to 47%) and 94% (95% CI, 86% to 97%), respectively. The 76-gene signature was confirmed as a strong prognostic factor in subgroups of estrogen receptor-positive patients, pre- and postmenopausal patients, and patients with tumor sizes 20 mm or smaller. The subgroup of patients with estrogen receptor-negative tumors was considered too small to perform a separate analysis. CONCLUSION Our data provide a strong methodologic and clinical multicenter validation of the predefined prognostic 76-gene signature in LNN breast cancer patients.

Phase III Study Comparing Exemestane With Tamoxifen As First-Line Hormonal Treatment of Metastatic Breast Cancer in Postmenopausal Women: The European Organisation for Research and Treatment of Cancer Breast Cancer Cooperative Group

PURPOSE This phase III randomized open-label clinical trial was designed to evaluate the efficacy and safety of the steroidal aromatase inactivator exemestane versus the antiestrogen tamoxifen as first-line treatment for metastatic breast cancer (MBC) in postmenopausal women. PATIENTS AND METHODS The study was conducted at 81 centers and enrolled postmenopausal patients with measurable hormone-sensitive metastatic or locally advanced breast cancer. Prior adjuvant chemotherapy and/or tamoxifen were allowed. One previous chemotherapy regimen and no prior hormone therapy for advanced disease were permitted. Patients were randomly assigned to receive exemestane 25 mg or tamoxifen 20 mg orally once daily until disease progression or unacceptable toxicity occurred. RESULTS A total of 371 patients enrolled at 79 sites (182 exemestane, 189 tamoxifen) were included in the analysis. Both treatments were generally well tolerated without major toxicity. Overall response rate was greater for exemestane than for tamoxifen treatment (46% v 31%; odds ratio = 1.85; 95% CI, 1.21 to 2.82; P = .005). Median progression-free survival (PFS) was longer with exemestane (9.9 months; 95% CI, 8.7 to 11.8 months) than with tamoxifen (5.8 months; 95% CI, 5.3 to 8.1 months). However, these early differences (Wilcoxon P = .028) did not translate to a longer-term benefit in PFS, the primary study end point (log-rank P = .121). There was also no difference in survival between both study arms. CONCLUSION Exemestane is an effective and well-tolerated first-line hormonal treatment for postmenopausal women with MBC and offers significant early improvement in time to tumor progression when compared with tamoxifen.

Effects of Tamoxifen and Exemestane on Cognitive Functioning of Postmenopausal Patients With Breast Cancer: Results From the Neuropsychological Side Study of the Tamoxifen and Exemestane Adjuvant Multinational Trial

PURPOSE To evaluate the influence of adjuvant tamoxifen and exemestane on cognitive functioning in postmenopausal patients with breast cancer (BC). PATIENTS AND METHODS Neuropsychological assessments were performed before the start (T1) and after 1 year of adjuvant endocrine treatment (T2) in Dutch postmenopausal patients with BC, who did not receive chemotherapy. Patients participated in the international Tamoxifen and Exemestane Adjuvant Multinational trial, a prospective randomized study investigating tamoxifen versus exemestane as adjuvant therapy for hormone-sensitive BC. RESULTS Participants included 80 tamoxifen users (mean age, 68.7 years; range 51 to 84), 99 exemestane users (mean age, 68.3 years; range, 50 to 82), and 120 healthy controls (mean age, 66.2 years; range, 49 to 86). At T2, after adjustment for T1 performance, exemestane users did not perform statistically significantly worse than healthy controls on any cognitive domain. In contrast, tamoxifen users performed statistically significantly worse than healthy controls on verbal memory (P < .01; Cohens d = .43) and executive functioning (P = .01; Cohens d = .40), and statistically significantly worse than exemestane users on information processing speed (P = .02; Cohens d = .36). With respect to visual memory, working memory, verbal fluency, reaction speed, and motor speed, no significant differences between the three groups were found. CONCLUSION After 1 year of adjuvant therapy, tamoxifen use is associated with statistically significant lower functioning in verbal memory and executive functioning, whereas exemestane use is not associated with statistically significant lower cognitive functioning in postmenopausal patients with BC. Our results accentuate the need to include assessments of cognitive effects of adjuvant endocrine treatment in long-term safety studies.

High Prevalence of Premalignant Lesions in Prophylactically Removed Breasts From Women at Hereditary Risk for Breast Cancer

PURPOSE Women with a hereditary predisposition for breast cancer have an extremely high risk of developing invasive breast carcinoma, and many women consider prophylactic mastectomy to avoid this risk. The use of prophylactic mastectomy is still debated. Identification of frequent premalignant lesions in mastectomy specimens would support the preventive concept of prophylactic mastectomy. PATIENTS AND METHODS We performed a prospective study of breast specimens from 67 women at extremely high genetic risk of breast cancer, with or without previous breast cancer, who were undergoing prophylactic mastectomy (66% were carriers of a BRCA1 or BRCA2 mutation). Breast specimens were studied by radiographic and macroscopic examination of 5-mm tissue slices, with subsequent histology of suspicious lesions and random samples from each quadrant of the breast and the nipple area. RESULTS In 57% of the women, one or more different types of high-risk histopathologic lesions were present: 37% atypical lobular hyperplasia, 39% atypical ductal hyperplasia, 25% lobular carcinoma-in-situ, and 15% ductal carcinoma-in-situ. A 4-mm invasive ductal carcinoma was found in one woman with ductal carcinoma-in-situ. None of these lesions was detected at palpation or mammography, which were performed before the mastectomy. The presence of high-risk lesions was independently related to age older than 40 years (odds ratio, 6.6; P =.01) and to bilateral oophorectomy before prophylactic mastectomy (odds ratio, 0.2; P = 0.02). CONCLUSION Many women at high risk of hereditary breast cancer develop high-risk histopathologic lesions, especially after the age of 40 years. Surveillance does not detect such high-risk histopathologic lesions.

Expression of the transcription factor Ets-1 is an independent prognostic marker for relapse-free survival in breast cancer.

The transcription factor Ets-1 regulates the expression of several angiogenic and extracellular matrix remodeling factors, and might be implicated in disease progression of breast cancer. In the present study, the prognostic value of Ets-1 expression was assessed by quantitative real-time fluorescence RT–PCR in 123 sporadic primary breast cancer samples of patients with a median follow-up time of 62 months. Ets-1 expression levels correlated significantly with VEGF and PAI-1 in the same tissue. In univariate (P=0.0011) and multivariate (P=0.005) analyses, Ets-1 expression showed significant prognostic value for relapse-free survival. Ets-1 is a strong, independent predictor of poor prognosis in breast cancer. This seems – at least in part – to be attributable to its role in transcriptional regulation of factors involved in angiogenesis (VEGF), and extracellular matrix remodeling (PAI-1).

Tamoxifen resistance in breast cancer: elucidating mechanisms.

Tamoxifen has been used for the systemic treatment of patients with breast cancer for nearly three decades. Treatment success is primarily dependent on the presence of the estrogen receptor (ER) in the breast carcinoma. While about half of patients with advanced ER-positive disease immediately fail to respond to tamoxifen, in the responding patients the disease ultimately progresses to a resistant phenotype.The possible causes for intrinsic and acquired resistance have been attributed to the pharmacology of tamoxifen, alterations in the structure and function of the ER, the interactions with the tumour environment and genetic alterations in the tumour cells. So far no prominent mechanism leading to resistance has been identified.The recent results of a functional screen for breast cancer antiestrogen resistance (BCAR) genes responsible for development of tamoxifen resistance in human breast cancer cells are reviewed. Individual BCAR genes can transform estrogen-dependent breast cancer cells into estrogen-independent and tamoxifen-resistant cells in vitro. Furthermore, high levels of BCAR1/p130Cas protein in ER-positive primary breast tumours are associated with intrinsic resistance to tamoxifen treatment. These results indicate a prominent role for alternative growth control pathways independent of ER signalling in intrinsic tamoxifen resistance of ER-positive breast carcinomas.Deciphering the differentiation characteristics of normal and malignant breast epithelial cells with respect to proliferation control and regulation of cell death (apoptosis) is essential for understanding therapy response and development of resistance of breast carcinoma.

First line hormonal treatment (HT) for metastatic breast cancer (MBC) with exemestane (E) or tamoxifen (T) in postmenopausal patients (pts) - A randomized phase III trial of the EORTC Breast Group

515 Background: E is an aromatase inactivator, with demonstrated efficacy in MBC progressing under T, which remained standard 1st line HT over decades. The randomized EORTC phase II trial of E vs T, which showed promising activity in 1st line MBC (Ann. Oncol. 2003, 14: 1391-8) was extended in a phase III reported here, aiming at a true comparison of efficacy and tolerability of both drugs. METHODS Postmenopausal MBC pts with ECOG PS ≤2 and measurable, hormone responsive disease (ER &/or PgR + or unknown with disease free interval >2y) previously untreated with HT for MBC, were randomized to receive open label E 25mg or T 20mg daily. One prior chemotherapy (CT) for MBC was permitted. Prior adjuvant T was allowed if treatment free interval exceeded 6 mo. The trial was powered to detect an increase in median progression free survival (PFS, primary endpoint) of 3 mo in favor of E. Secondary endpoints were survival and tolerability. All analyses were intent to treat. RESULTS 382 pts accrued by 81 centers received E (190 pts) or T (192 pts). Both groups were balanced for median age (62.5), prior adjuvant CT (E 28%, T 29%) or CT for MBC (E 8%, T 7%), hormone receptor status, PS, prior adjuvant T (21% both) and dominant metastatic site (visceral E 48%, T 47%; bone E 35%, T 36%; soft tissue E 17%, T 17%). On 15/12/2003, 286 events (progression or death under treatment) and 136 deaths were reported. The median PFS is significantly longer under E than T (10.9 vs 6.7 months, p 0.04) with an HR of 0.79 (95% CI 0.62 - 0.99) in favor of E. Best response rates (%) under E were CR 7.4, PR 36.8, SD 27.4, PD 18.4, NE (not evaluable) 10.0; under T, CR 2.6, PR 26.6, SD 37.0, PD 27.6, NE 6.2). No pt withdrew due to toxicity. Grade 2-3 toxicities observed in ≥10% were bone pain (E 12%, T 18%), other pain (E 7%, T 14%) and hot flashes (E 5%, T 12%). CONCLUSIONS E is a safe and highly active steroidal aromatase inactivator, superior to T in MBC. In view of its efficacy and excellent tolerance, E represents a good choice as first line therapy in hormone responsive MBC. Its safety profile makes E also attractive for use in the adjuvant and preventive settings. [Table: see text].

Prospective Multicenter Validation of the Independent Prognostic Value of the Mitotic Activity Index in Lymph Node–Negative Breast Cancer Patients Younger Than 55 Years

PURPOSE To validate the independent strong prognostic value of mitotic activity index (MAI) in lymph node (LN) -negative invasive breast cancer patients younger than 55 years in a nationwide multicenter prospective study. PATIENTS AND METHODS Analysis of routinely assessed MAI and other prognosticators in 516 patients (median follow-up, 118 months; range, 8 to 185 months), without systemic adjuvant therapy or previous malignancies. RESULTS Distant metastases occurred in 127 patients (24.6%); 90 (17.4%) died as a result of metastases. MAI (< 10, > or = 10) showed strong association with recurrence (hazard ratio [HR], 3.12; 95% CI, 2.17 to 4.50; P < or = .0001) and mortality (HR, 4.42; 95% CI, 2.79 to 7.01; P < .0001). The absolute difference in 10-year Kaplan-Meier estimates of time to distant recurrence as well as survival was 22% between MAI less than 10 versus > or = 10. This effect was independent of age, estrogen receptor (ER) status, and tumor diameter (which were significant prognosticators). In multivariate analysis with regard to patient age, tumor diameter, grade, ER status, and the St Gallen criterion, MAI proved to be an independent and the strongest prognosticator. Tubular formation (TF) and nuclear atypia (NA), as constituents of (expert revised) grade, had no (for TF) or limited (for NA, P = .048) additional prognostic value to the MAI. In the group with MAI less than 10, MAI less than 3 versus more than 3 had additional value but the classical threshold of 0 to 5 v 6 to 10 did not. With this additional subdivision of MAI as less than 3, 3 to 9, and more than 9, NA lost its additive prognostic value. CONCLUSION The MAI is the strongest, most widely available, easily assessable, inexpensive, well-reproducible prognosticator and is well suited to routinely differentiate between high- and low-risk LN-negative breast cancer patients younger than 55 years.

Fatigue and Relating Factors in High-Risk Breast Cancer Patients Treated With Adjuvant Standard or High-Dose Chemotherapy: A Longitudinal Study

PURPOSE Determine whether standard or high-dose chemotherapy leads to changes in fatigue, hemoglobin (Hb), mental health, muscle and joint pain, and menopausal status from pre- to post-treatment and to evaluate whether fatigue is associated with these factors in disease-free breast cancer patients. PATIENTS AND METHODS Eight hundred eighty-five patients were randomly assigned between two chemotherapy regimens both followed by radiotherapy and tamoxifen. Fatigue was assessed using vitality scale (score < or = 46 defined as fatigue), poor mental health using mental health scale (score < or = 56 defined as poor mental health) both of Short-Form 36, muscle and joint pain with Rotterdam Symptom Checklist, and Hb levels were assessed before and 1, 2, and 3 years after chemotherapy. RESULTS Fatigue was reported in 20% of 430 assessable patients (202 standard-dose, 228 high-dose) with at least a 3-year follow-up, without change over time or difference between treatment arms. Mean Hb levels were lower following high-dose chemotherapy. Only 5% of patients experienced fatigue and anemia. Mental health score was the strongest fatigue predictor at all assessment moments. Menopausal status had no effect on fatigue. Linear mixed effect models showed that the higher the Hb level (P = .0006) and mental health score (P < .0001), the less fatigue was experienced. Joint (P < .0001) and muscle pain (P = .0283) were associated with more fatigue. CONCLUSION In 3 years after treatment, no significant differences in fatigue were found between standard and high-dose chemotherapy. Fatigue did not change over time. The strongest fatigue predictor was poor mental health.

Cyclin-E is a strong predictor of endocrine therapy failure in human breast cancer.

Recently, cyclin-E was reported to be the most prominent prognostic factor for breast cancer outcome described so far, even surpassing axillary nodal involvement. Earlier studies on the prognostic value of cyclin-E in breast cancer, however, yielded heterogeneous results. Therefore, we set out to confirm and extend these results by quantitative Taqman RT–PCR of cyclin-E levels in 277 resectable breast cancers. Cyclin-E levels were not associated with relapse-free survival (RFS) or overall survival (OS) in the total cohort of patients, or in the subset of patients without involved lymph nodes that were not treated with adjuvant systemic therapy. Besides several classical clinicopathological factors, the interaction between cyclin-E and adjuvant endocrine therapy (P=0.01, HR=3.04, 95% CI: 1.30–7.09) was found to contribute significantly in multivariate analyses. Cyclin-E levels were associated with poor RFS specifically in patients treated with adjuvant endocrine therapy (n=108, P=0.001, HR=4.01, 95% CI: 1.76–9.12), independent of estrogen receptor status. In conclusion, cyclin-E is not a pure prognostic factor in breast cancer, but rather a predictor of failure of endocrine therapy. Differences in literature on the presumed prognostic value of cyclin-E may be due to differences in treatment. Assessment of cyclin-E levels can aid in improving adjuvant treatment selection.