Masakazu Toi

Personalizing the treatment of women with early breast cancer: highlights of the St Gallen International Expert Consensus on the Primary Therapy of Early Breast Cancer 2013

The 13th St Gallen International Breast Cancer Conference (2013) Expert Panel reviewed and endorsed substantial new evidence on aspects of the local and regional therapies for early breast cancer, supporting less extensive surgery to the axilla and shorter durations of radiation therapy. It refined its earlier approach to the classification and management of luminal disease in the absence of amplification or overexpression of the Human Epidermal growth factor Receptor 2 (HER2) oncogene, while retaining essentially unchanged recommendations for the systemic adjuvant therapy of HER2-positive and ‘triple-negative’ disease. The Panel again accepted that conventional clinico-pathological factors provided a surrogate subtype classification, while noting that in those areas of the world where multi-gene molecular assays are readily available many clinicians prefer to base chemotherapy decisions for patients with luminal disease on these genomic results rather than the surrogate subtype definitions. Several multi-gene molecular assays were recognized as providing accurate and reproducible prognostic information, and in some cases prediction of response to chemotherapy. Cost and availability preclude their application in many environments at the present time. Broad treatment recommendations are presented. Such recommendations do not imply that each Panel member agrees: indeed, among more than 100 questions, only one (trastuzumab duration) commanded 100% agreement. The various recommendations in fact carried differing degrees of support, as reflected in the nuanced wording of the text below and in the votes recorded in supplementary Appendix S1, available at Annals of Oncology online. Detailed decisions on treatment will as always involve clinical consideration of disease extent, host factors, patient preferences and social and economic constraints.

Nuclear factor-κB inhibitors as sensitizers to anticancer drugs

The cytotoxicity of chemotherapeutic agents is attributed to apoptosis. Acquired resistance to the effects of chemotherapy has emerged as a significant impediment to effective cancer therapy. One feature that cytotoxic treatments of cancer have in common is their activation of the transcription factor nuclear factor-κB (NF-κB), which regulates cell survival. NF-κB activation suppresses the apoptotic potential of chemotherapeutic agents and contributes to resistance. What evidence is there that inhibitors of NF-κB might promote apoptosis in cancer cells and can NF-κB inhibitors be used to overcome resistance to chemotherapeutic agents?

Association of vascular endothelial growth factor expression with tumor angiogenesis and with early relapse in primary breast cancer.

Angiogenesis is an independent prognostic indicator in breast cancer. In this report, the relationship between expression of vascular endothclial growth factor (VEGF; a selective mitogen for endothelial cells) and the microvessel density was examined in 103 primary breast cancers. The expression of VEGF was evaluated by immunocytochemical staining using anti‐VEGF antibody. The microvessel density, which was determined by immunostaining for factor VIII antigen, in VEGF‐rich tumors was clearly higher than that in VEGF‐poor tumors (P<0.01). There was a good correlation between VEGF expression and the increment of microvessel density. Furthermore, postoperative survey demonstrated that the relapse‐free survival rate of VEGF‐rich tumors was significantly worse than that of VEGF‐poor tumors. It was suggested that the expression of VEGF is closely associated with the promotion of angiogenesis and with early relapse in primary breast cancer.

Tumor angiogenesis in breast cancer: Its importance as a prognostic indicator and the association with vascular endothelial growth factor expression

SummaryThe importance of tumor angiogenesis in the process of tumor growth and progression in solid tumors has been widely accepted. We have investigated the significance of tumor angiogenesis as a prognostic indicator in a retrospective study including 328 primary breast cancer patients. The postoperative survey demonstrated that the microvessel density (MVD) evaluated by immunocytochemical staining for factor VIII-related antigen is a potent prognostic indicator. The relapse-free survival (RFS) rate of patients with over 100 microvessels/mm2 in a microscopic field was significantly worse compared to that of patients with less than 100 microvessels/mm2 (p<0.00001). The significance of MVD was found in both node-negative and node-positve patients (p< 0.005 and p<0.01, respectively). Multivariate analysis confirmed that MVD is an independent prognostic indicator for RFS. In the background factor analysis, MVD was significantly correlated with the number of metastatic nodes (p<0.01). In addition, the immunocytochemical analysis for vascular endothelial growth factor (VEGF) demonstrated a close association between the increase in MVD and the expression of VEGF (p<0.001). VEGF status also was a significant prognostic indicator in univariate analysis for RFS (p<0.01). It was concluded that MVD is a potent prognostic indicator in primary breast cancer. Furthermore, it was also suggested that VEGF plays crucial roles in the promotion of angiogenesis in breast cancer.

Adjuvant bevacizumab-containing therapy in triple-negative breast cancer (BEATRICE): primary results of a randomised, phase 3 trial

BACKGROUND The addition of bevacizumab to chemotherapy improves progression-free survival in metastatic breast cancer and pathological complete response rates in the neoadjuvant setting. Micrometastases are dependent on angiogenesis, suggesting that patients might benefit from anti-angiogenic strategies in the adjuvant setting. We therefore assessed the addition of bevacizumab to chemotherapy in the adjuvant setting for women with triple-negative breast cancer. METHODS For this open-label, randomised phase 3 trial we recruited patients with centrally confirmed triple-negative operable primary invasive breast cancer from 360 sites in 37 countries. We randomly allocated patients aged 18 years or older (1:1 with block randomisation; stratified by nodal status, chemotherapy [with an anthracycline, taxane, or both], hormone receptor status [negative vs low], and type of surgery) to receive a minimum of four cycles of chemotherapy either alone or with bevacizumab (equivalent of 5 mg/kg every week for 1 year). The primary endpoint was invasive disease-free survival (IDFS). Efficacy analyses were based on the intention-to-treat population, safety analyses were done on all patients who received at least one dose of study drug, and plasma biomarker analyses were done on all treated patients consenting to biomarker analyses and providing a measurable baseline plasma sample. This trial is registered with ClinicalTrials.gov, number NCT00528567. FINDINGS Between Dec 3, 2007, and March 8, 2010, we randomly assigned 1290 patients to receive chemotherapy alone and 1301 to receive bevacizumab plus chemotherapy. Most patients received anthracycline-containing therapy; 1638 (63%) of the 2591 patients had node-negative disease. At the time of analysis of IDFS, median follow-up was 31·5 months (IQR 25·6-36·8) in the chemotherapy-alone group and 32·0 months (27·5-36·9) in the bevacizumab group. At the time of the primary analysis, IDFS events had been reported in 205 patients (16%) in the chemotherapy-alone group and in 188 patients (14%) in the bevacizumab group (hazard ratio [HR] in stratified log-rank analysis 0·87, 95% CI 0·72-1·07; p=0·18). 3-year IDFS was 82·7% (95% CI 80·5-85·0) with chemotherapy alone and 83·7% (81·4-86·0) with bevacizumab and chemotherapy. After 200 deaths, no difference in overall survival was noted between the groups (HR 0·84, 95% CI 0·64-1·12; p=0·23). Exploratory biomarker assessment suggests that patients with high pre-treatment plasma VEGFR-2 might benefit from the addition of bevacizumab (Cox interaction test p=0·029). Use of bevacizumab versus chemotherapy alone was associated with increased incidences of grade 3 or worse hypertension (154 patients [12%] vs eight patients [1%]), severe cardiac events occurring at any point during the 18-month safety reporting period (19 [1%] vs two [<0·5%]), and treatment discontinuation (bevacizumab, chemotherapy, or both; 256 [20%] vs 30 [2%]); we recorded no increase in fatal adverse events with bevacizumab (four [<0·5%] vs three [<0·5%]). INTERPRETATION Bevacizumab cannot be recommended as adjuvant treatment in unselected patients with triple-negative breast cancer. Further follow-up is needed to assess the potential effect of bevacizumab on overall survival.

Everolimus for women with trastuzumab-resistant, HER2-positive, advanced breast cancer (BOLERO-3): a randomised, double-blind, placebo-controlled phase 3 trial

BACKGROUND Disease progression in patients with HER2-positive breast cancer receiving trastuzumab might be associated with activation of the PI3K/Akt/mTOR intracellular signalling pathway. We aimed to assess whether the addition of the mTOR inhibitor everolimus to trastuzumab might restore sensitivity to trastuzumab. METHODS In this randomised, double-blind, placebo-controlled, phase 3 trial, we recruited women with HER2-positive, trastuzumab-resistant, advanced breast carcinoma who had previously received taxane therapy. Eligible patients were randomly assigned (1:1) using a central patient screening and randomisation system to daily everolimus (5 mg/day) plus weekly trastuzumab (2 mg/kg) and vinorelbine (25 mg/m(2)) or to placebo plus trastuzumab plus vinorelbine, in 3-week cycles, stratified by previous lapatinib use. The primary endpoint was progression-free survival (PFS) by local assessment in the intention-to-treat population. We report the final analysis for PFS; overall survival follow-up is still in progress. This trial is registered with ClinicalTrials.gov, number NCT01007942. FINDINGS Between Oct 26, 2009, and May 23, 2012, 569 patients were randomly assigned to everolimus (n=284) or placebo (n=285). Median follow-up at the time of analysis was 20.2 months (IQR 15.0-27.1). Median PFS was 7.00 months (95% CI 6.74-8.18) with everolimus and 5.78 months (5.49-6.90) with placebo (hazard ratio 0.78 [95% CI 0.65-0.95]; p=0.0067). The most common grade 3-4 adverse events were neutropenia (204 [73%] of 280 patients in the everolimus group vs 175 [62%] of 282 patients in the placebo group), leucopenia (106 [38%] vs 82 [29%]), anaemia (53 [19%] vs 17 [6%]), febrile neutropenia (44 [16%] vs ten [4%]), stomatitis (37 [13%] vs four [1%]), and fatigue (34 [12%] vs 11 [4%]). Serious adverse events were reported in 117 (42%) patients in the everolimus group and 55 (20%) in the placebo group; two on-treatment deaths due to adverse events occurred in each group. INTERPRETATION The addition of everolimus to trastuzumab plus vinorelbine significantly prolongs PFS in patients with trastuzumab-resistant and taxane-pretreated, HER2-positive, advanced breast cancer. The clinical benefit should be considered in the context of the adverse event profile in this population.

Vascular endothelial growth factor: its prognostic, predictive, and therapeutic implications

Since the discovery that cancer development requires the growth of new blood vessels, many investigations have revealed the key molecules in the regulation of new vessel formation. One of the most important of these molecules is vascular endothelial growth factor (VEGF)--an endothelial-cell-specific mitogen and survival factor. VEGF also causes increased vascular permeability and recruits progenitor endothelial cells from the bone marrow. Clinical observations have confirmed that VEGF status is closely associated with the extent of neovascularisation and prognosis in many solid tumours. VEGF status is predictive of resistance to various treatments, including radiotherapy, chemotherapy, and endocrine therapy. Preliminary results also indicate that anti-VEGF treatment suppresses cancer progression without serious toxic effects. Various approaches for the control of cancers involving inhibition of the activity of VEGF are currently being investigated. This review considers the clinical implications of VEGF, particularly its prognostic, predictive, and therapeutic value.

Significant correlation of monocyte chemoattractant protein‐1 expression with neovascularization and progression of breast carcinoma

Macrophages often infiltrate into solid tumor tissues. Tumor‐associated macrophages (TAMs) are known to play a crucial role in tumor progression. Monocyte chemoattractant protein‐1 (MCP‐1) is one of the major chemokines capable of inducing chemotactic migration of monocytes.

Quantitative analysis of vascular endothelial growth factor in primary breast cancer

Recent clinical studies have demonstrated that tumor angiogenesis is a potent prognostic indicator for breast cancer patients. The quantitation of endothelial growth factors is thought to be useful to assess angiogenic phenotype in the tumor. Among the many new endothelial growth factors, vascular endothelial growth factor (VEGF) is known to be particularly responsible for promoting the neovascularization in human breast cancer.

Significance of HDAC6 regulation via estrogen signaling for cell motility and prognosis in estrogen receptor-positive breast cancer

Histone deacetylase (HDAC) 6 is a subtype of the HDAC family; it deacetylates α-tubulin and increases cell motility. Here, we investigate the impact of an alteration of HDAC6 expression in estrogen receptor α (ER)-positive breast cancer MCF-7 cells, as we identified that HDAC6 is a novel estrogen-regulated gene. MCF-7 treated with estradiol showed increased expression of HDAC6 mRNA and protein and a four-fold increase in cell motility in a migration assay. Cell motility was increased to the same degree by stably transfecting the HDAC6 expression vector into MCF-7 cells. In both cases, the cells changed in appearance from their original round shape to an axon-extended shape, like a neuronal cell. This HDAC6 accumulation caused the deacetylation of α-tubulin. Either the selective estrogen receptor modulator tamoxifen (TAM) or the pure antiestrogen ICI 182,780 prevented estradiol-induced HDAC6 accumulation and deacetylation of α-tubulin, leading to reduced cell motility. Tubacin, an inhibitory molecule that binds to the tubulin deacetylation domain of HDAC6, also prevented estradiol-stimulated cell migration. Finally, we evaluated HDAC6 protein expression in 139 consecutively archived human breast cancer tissues by immunohistochemical staining. The prognostic analyses for these patients revealed no significant differences based on HDAC6 expression. However, subset analysis of ER-positive patients who received adjuvant treatment with TAM (n=67) showed a statistically significant difference in relapse-free survival and overall survival in favor of the HDAC6-positive group (P<0.02 and P<0.05, respectively). HDAC6 expression was an independent prognostic indicator by multivariate analysis (odds ratio=2.82, P=0.047). These results indicate the biological significance of HDAC6 regulation via estrogen signaling.