The effect of 1-day multidisciplinary clinic on breast cancer treatment.

PURPOSE: A delay in breast cancer treatment is associated with inferior survival outcomes; however, no clear guidelines exist defining the appropriate time frame from diagnosis to definitive treatment of breast cancer. A multidisciplinary approach for breast cancer treatment can minimize the time from diagnosis to first treatment. We hypothesized single-day multidisciplinary clinic (MDC) may accelerate the time to first treatment on complex breast cancer cases at our institution. METHODS: We identified patients who were treated at Johns Hopkins for stage II or III breast cancer, who were at least 18 years of age, and were seen in a new single-day MDC with coordination between two or three specialties or by specialists from varying disciplines on different days (IDC). Patients who initiated treatment between May 2015 (initiation of MDC clinic) and December 2017 were included in our study. RESULTS: A total of 296 patient records were reviewed independently. The mean (SD) patient age was 55 (13) years. The median time to first neoadjuvant chemotherapy (NACT) was significantly reduced for patients seen in the MDC (12.7 days), compared to those seen at the IDC (24.4 days, logrank p < 0.001). The median time to definitive surgery was similar between groups (31 and 32 days for the MDC and IDC cohorts, respectively). CONCLUSIONS: A single-day MDC visit is associated with a reduced time from diagnosis to NACT. Further studies are needed to determine if a shorter interval can improve the management and the outcome of complex breast cancer cases.

Sharing in care: engaging care partners in the care and communication of breast cancer patients.

PURPOSE: Family is often overlooked in cancer care. We developed a patient-family agenda setting intervention to engage family in cancer care communication. METHODS: We conducted a pilot randomized controlled trial (NCT03283553) of patients on active treatment for breast cancer and their family "care partner." Intervention dyads (n = 69) completed a self-administered checklist to clarify care partner roles, establish a shared visit agenda, and facilitate MyChart patient portal access. Control dyads (n = 63) received usual care. We assessed intervention acceptability and initial effects from post-visit surveys and MyChart utilization at 6 weeks. RESULTS: At baseline, most patients (89.4%) but few care partners (1.5%) were registered for MyChart. Most patients (79.4%) wanted their care partner to have access to their records and 39.4% of care partners reported accessing MyChart. In completing the checklist, patients and care partners endorsed active communication roles for the care partner and identified a similar visit agenda: most (> 90%) reported the checklist was easy, useful, and recommended it to others. At 6 weeks, intervention (vs control) care partners were more likely to be registered for MyChart (75.4% vs 1.6%; p < 0.001), to have logged in (43.5% vs 0%; p < 0.001) and viewed clinical notes (30.4% vs 0%; p < 0.001), but were no more likely to exchange direct messages with clinicians (1.5% vs 0%; p = 0.175). No differences in patients' MyChart use were observed, but intervention patients more often viewed clinical notes (50.7% vs 9.5%; p < 0.001). CONCLUSIONS: A patient-family agenda setting intervention was acceptable and affected online practices of cancer patients and care partners.

Recent progress in the diagnosis and treatment of ovarian cancer.

Epithelial ovarian cancer is the most lethal of the gynecologic malignancies, largely due to the advanced stage at diagnosis in most patients. Screening strategies using ultrasound and the cancer antigen (CA) 125 tumor marker are currently under study and may lower stage at diagnosis but have not yet been shown to improve survival. Women who have inherited a deleterious mutation in the BRCA1 or BRCA2 gene and those with the Lynch syndrome (hereditary nonpolyposis colorectal cancer) have the highest risk of developing ovarian cancer but account for only approximately 10% of those with the disease. Other less common and less well-defined genetic syndromes may increase the risk of ovarian cancer, but their contribution to genetic risk is small. A clear etiology for sporadic ovarian cancer has not been identified, but risk is affected by reproductive and hormonal factors. Surgery has a unique role in ovarian cancer, as it is used not only for diagnosis and staging but also therapeutically, even in patients with widely disseminated, advanced disease. Ovarian cancer is highly sensitive to chemotherapy drugs, particularly the platinum agents, and most patients will attain a remission with initial treatment. Recent advances in the delivery of chemotherapy using the intraperitoneal route have further improved survival after initial therapy. Although the majority of ovarian cancer patients will respond to initial chemotherapy, most will ultimately develop disease recurrence. Chemotherapy for recurrent disease includes platinum-based, multiagent regimens for women whose disease recurs more than 6 to 12 months after the completion of initial therapy and sequential single agents for those whose disease recurs earlier. New targeted biologic agents, particularly those involved with the vascular endothelial growth factor pathway and those targeting the poly (ADP-ribose) polymerase (PARP) enzyme, hold great promise for improving the outcome of ovarian cancer.

Phase 1b safety study of farletuzumab, carboplatin and pegylated liposomal doxorubicin in patients with platinum-sensitive epithelial ovarian cancer.

OBJECTIVE: Farletuzumab is a humanized monoclonal antibody that binds to folate receptor alpha, over-expressed in epithelial ovarian cancer (EOC) but largely absent in normal tissue. Previously, carboplatin plus pegylated liposomal doxorubicin showed superior progression-free survival and an improved therapeutic index compared with carboplatin/paclitaxel in relapsed platinum-sensitive EOC. This study assessed safety of farletuzumab/carboplatin/pegylated liposomal doxorubicin in women with platinum-sensitive recurrent EOC. METHODS: This multicenter, single-arm study enrolled patients with platinum-sensitive EOC in first or second relapse for treatment with weekly farletuzumab 2.5mg/kg plus carboplatin AUC5-6 and pegylated liposomal doxorubicin 30mg/m(2) every 4weeks for 6cycles. Subsequently, maintenance with single-agent farletuzumab 2.5mg/kg once weekly or farletuzumab 7.5mg/kg once every three weeks continued until progression. The primary objective was to assess the safety of farletuzumab/carboplatin/pegylated liposomal doxorubicin. RESULTS: Fifteen patients received a median of 12.0cycles (range, 3-26) of farletuzumab as combination therapy or maintenance, for a median of 45.0weeks (range 9-95). Farletuzumab/carboplatin/pegylated liposomal doxorubicin was generally well tolerated, with no farletuzumab-related grades 3-4 adverse events. The most commonly reported adverse events were associated with combination chemotherapy: fatigue (73.3%), nausea (46.7%), and neutropenia (40%). Ten patients had grade ≥3 adverse events, most frequently neutropenia and fatigue. No cardiac toxicity was seen. Best overall responses (RECIST) were a complete response for one patient, partial responses for 10 patients, and stable disease for four patients. CONCLUSIONS: Farletuzumab plus carboplatin/pegylated liposomal doxorubicin in women with platinum-sensitive EOC demonstrated a safety profile consistent with that of carboplatin plus pegylated liposomal doxorubicin.

Mutation of a single allele of the cancer susceptibility gene BRCA1 leads to genomic instability in human breast epithelial cells.

Biallelic inactivation of cancer susceptibility gene BRCA1 leads to breast and ovarian carcinogenesis. Paradoxically, BRCA1 deficiency in mice results in early embryonic lethality, and similarly, lack of BRCA1 in human cells is thought to result in cellular lethality in view of BRCA1's essential function. To survive homozygous BRCA1 inactivation during tumorigenesis, precancerous cells must accumulate additional genetic alterations, such as p53 mutations, but this requirement for an extra genetic "hit" contradicts the two-hit theory for the accelerated carcinogenesis associated with familial cancer syndromes. Here, we show that heterozygous BRCA1 inactivation results in genomic instability in nontumorigenic human breast epithelial cells in vitro and in vivo. Using somatic cell gene targeting, we demonstrated that a heterozygous BRCA1 185delAG mutation confers impaired homology-mediated DNA repair and hypersensitivity to genotoxic stress. Heterozygous mutant BRCA1 cell clones also showed a higher degree of gene copy number loss and loss of heterozygosity in SNP array analyses. In BRCA1 heterozygous clones and nontumorigenic breast epithelial tissues from BRCA mutation carriers, FISH revealed elevated genomic instability when compared with their respective controls. Thus, BRCA1 haploinsufficiency may accelerate hereditary breast carcinogenesis by facilitating additional genetic alterations.

HER2-directed therapy for metastatic breast cancer.

Human epidermal growth factor receptor 2 (HER2) overexpression drives the biology of 20% of breast cancers, and predicts a poor prognosis for patients. HER2-targeted therapies significantly improve outcomes for HER2-positive patients with both early and metastatic breast cancer. Currently three HER2-targeted agents, trastuzumab (Herceptin), lapatinib (Tykerb), and pertuzumab (Perjeta), are available for the treatment of HER2-positive metastatic breast cancer (MBC). Numerous studies have attempted to optimize their use by combining them with each other, or with endocrine and cytotoxic therapies. Most recently, the FDA approved the combination of trastuzumab, pertuzumab, and docetaxel as first-line treatment for MBC, and in late February 2013 approved a fourth HER2-targeted agent, trastuzumab emtansine (T-DM1, Kadcyla), for accelerated approval. These advances create a number of clinical dilemmas, including identification of the optimal sequence of HER2-targeted agents and the best drug combinations to use, as well as the recognition of primary and acquired drug resistance. In this article, we review clinical data informing the effective management of HER2-positive MBC.

The ENGAGE study: evaluation of a conversational virtual agent that provides tailored pre-test genetic education to cancer patients.

PURPOSE: Novel approaches are needed to ensure all patients with cancer have access to quality genetic education before genetic testing to enable informed treatment decisions. The purpose of this study was to test the use of an artificial intelligence (AI) intervention for the delivery of genetic education by non-genetic providers to patients with cancer undergoing active treatment. METHODS: A conversational AI-based application was developed on the HealthFAX platform to provide tailored genetic education to patients with cancer and tested at Johns Hopkins Hospital between April 2021 and Feb 2022. Patients' responses around the adoption, use, and experience of the AI application were assessed. RESULTS: Out of 64 individuals who consented to the study, 51 accessed the tool. The responding participants had a mean age of 61 years (ranging from 30-90 years) with 39 individuals undergoing active treatment for breast cancer and 12 for advanced prostate cancer. All patients chose to complete the tool at home. The median time between study enrollment and AI application initiation was 1 day, and the median time to complete the application was 24 min. All participants in their survey responses felt that the tool was secure, easy to use, liked the convenience of viewing it at home, and felt it provided valuable information. Eighteen percent of participants viewed the application with a family member. Ninety-eight percent of the participants completed their genetic education prior to receiving their test results. In 16%, a pathogenic variant was identified. CONCLUSIONS: The 51 patients who adopted the AI application were highly satisfied with its usability and convenience. Our results support the continued evaluation of this cost-effective AI application in a large-scale study. IMPLICATIONS FOR CANCER SURVIVORS: Tailored pre-test genetic education can be successfully delivered to patients with cancer undergoing active treatment via an AI application at their convenience.

The growth response to androgen receptor signaling in ERα-negative human breast cells is dependent on p21 and mediated by MAPK activation.

INTRODUCTION: Although a high frequency of androgen receptor (AR) expression in human breast cancers has been described, exploiting this knowledge for therapy has been challenging. This is in part because androgens can either inhibit or stimulate cell proliferation in pre-clinical models of breast cancer. In addition, many breast cancers co-express other steroid hormone receptors that can affect AR signaling, further obfuscating the effects of androgens on breast cancer cells. METHODS: To create better-defined models of AR signaling in human breast epithelial cells, we took estrogen receptor (ER)-α-negative and progesterone receptor (PR)-negative human breast epithelial cell lines, both cancerous and non-cancerous, and engineered them to express AR, thus allowing the unambiguous study of AR signaling. We cloned a full-length cDNA of human AR, and expressed this transgene in MCF-10A non-tumorigenic human breast epithelial cells and MDA-MB-231 human breast-cancer cells. We characterized the responses to AR ligand binding using various assays, and used isogenic MCF-10A p21 knock-out cell lines expressing AR to demonstrate the requirement for p21 in mediating the proliferative responses to AR signaling in human breast epithelial cells. RESULTS: We found that hyperactivation of the mitogen-activated protein kinase (MAPK) pathway from both AR and epidermal growth factor receptor (EGFR) signaling resulted in a growth-inhibitory response, whereas MAPK signaling from either AR or EGFR activation resulted in cellular proliferation. Additionally, p21 gene knock-out studies confirmed that AR signaling/activation of the MAPK pathway is dependent on p21. CONCLUSIONS: These studies present a new model for the analysis of AR signaling in human breast epithelial cells lacking ERα/PR expression, providing an experimental system without the potential confounding effects of ERα/PR crosstalk. Using this system, we provide a mechanistic explanation for previous observations ascribing a dual role for AR signaling in human breast cancer cells. As previous reports have shown that approximately 40% of breast cancers can lack p21 expression, our data also identify potential new caveats for exploiting AR as a target for breast cancer therapy.

The adjuvant treatment of HER2-positive breast cancer.

OPINION STATEMENT: About 15-20% of patients with early stage breast cancer present with tumors that have overexpression or amplification of the human epidermal growth factor receptor 2 (HER2) gene. Before 2005, these individuals had an increased risk of recurrence and death, but since then their outcomes have substantially improved with the adoption in most countries of adjuvant trastuzumab as a standard component of therapy for HER2-positive early-stage breast cancer. Consequently, access to high-quality and accurate HER2 testing methods is critical to accurately determine HER2 status, guide treatment decisions, and ultimately improve clinical outcomes. In 2012, the humanized monoclonal anti-HER antibody trastuzumab was the only approved HER2-targeted therapy in the adjuvant setting. Data from the first generation of trials combining it with various chemotherapy regimens showed significant improvements in disease-free and overall survival (DFS/OS). Based on results from five randomized clinical trials, a trastuzumab-containing regimen for up to 1 year is now considered standard for all patients with HER2-positive tumors larger than 1 cm in size who would have fulfilled eligibility to those studies, and this recommendation is sometimes extended to patients with stage I tumors greater than 0.5 cm (T1b). Second generation adjuvant studies with other HER2-targeted agents like lapatinib and pertuzumab are ongoing, and newer drugs like T-DM1 and neratinib are being actively tested in the metastatic setting.

A randomized intervention involving family to improve communication in breast cancer care.

We examined the effects of a communication intervention to engage family care partners on patient portal (MyChart) use, illness understanding, satisfaction with cancer care, and symptoms of anxiety in a single-blind randomized trial of patients in treatment for breast cancer. Patient-family dyads were recruited and randomly assigned a self-administered checklist to clarify the care partner role, establish a shared visit agenda, and facilitate MyChart access (n = 63) or usual care (n = 55). Interviews administered at baseline, 3, 9 (primary endpoint), and 12 months assessed anxiety (GAD-2), mean FAMCARE satisfaction, and complete illness understanding (4 of 4 items correct). Time-stamped electronic interactions measured MyChart use. By 9 months, more intervention than control care partners registered for MyChart (77.8 % vs 1.8%; p < 0.001) and logged into the patient's account (61.2% vs 0% of those registered; p < 0.001), but few sent messages to clinicians (6.1% vs 0%; p = 0.247). More intervention than control patients viewed clinical notes (60.3% vs 32.7%; p = 0.003). No pre-post group differences in patient or care partner symptoms of anxiety, satisfaction, or complete illness understanding were found. Intervention patients whose care partners logged into MyChart were more likely to have complete illness understanding at 9 months (changed 70.0% to 80.0% vs 69.7% to 54.6%; p = 0.03); symptoms of anxiety were numerically lower (16.7% to 6.7% vs 15.2% to 15.2%; p = 0.24) and satisfaction numerically higher (15.8-16.2 vs 18.0-17.4; p = 0.25). A brief, scalable communication intervention led to greater care partner MyChart use and increased illness understanding among patients with more engaged care partners (NCT03283553).

The State of Cancer Care in the United Arab Emirates in 2020: Challenges and Recommendations, A report by the United Arab Emirates Oncology Task Force.

With cancer being the third leading cause of mortality in the United Arab Emirates (UAE), there has been significant investment from the government and private health care providers to enhance the quality of cancer care in the UAE. The UAE is a developing country with solid economic resources that can be utilized to improve cancer care across the country. There is limited data regarding the incidence, survival, and potential risk factors for cancer in the UAE. The UAE Oncology Task Force was established in 2019 by cancer care providers from across the UAE under the auspices of Emirates Oncology Society. In this paper we summarize the history of cancer care in the UAE, report the national cancer incidence, and outline current challenges and opportunities to enhance and standardize cancer care. We provide recommendations for policymakers and the UAE Oncology community for the delivery of high-quality cancer care. These recommendations are aligned with the UAE government's vision to reduce cancer mortality and provide high quality healthcare for its citizens.

Inhibition of the phosphatidylinositol 3-kinase/Akt pathway improves response of long-term estrogen-deprived breast cancer xenografts to antiestrogens.

PURPOSE: Aromatase inhibitors that block the synthesis of estrogen are proving to be superior to antiestrogens and may replace tamoxifen as first-line treatment for postmenopausal estrogen receptor (ER)-positive breast cancer patients. However, acquisition of resistance to all forms of treatments is inevitable and a major clinical concern. In this study, we have investigated the effects of long-term estrogen deprivation in the breast cancer xenograft model and whether sensitivity to antiestrogens can be restored in vivo. We also compared whether combining wortmannin with tamoxifen or fulvestrant inhibited tumor growth better than either drug alone. EXPERIMENTAL DESIGN: Long-term estrogen-deprived aromatase-transfected human ER-positive breast cancer cells (UMB-1Ca) were grown as tumors in ovariectomized athymic nude mice. Twelve weeks after inoculation, when tumors reached 300 mm(3), animals were grouped and injected with vehicle, Delta(4)A, letrozole, tamoxifen, fulvestrant, wortmannin, tamoxifen plus wortmannin, and wortmannin plus fulvestrant. Tumor volumes were measured weekly. RESULTS: Tumors of UMB-1Ca cells grew equally well with and without androstenedione, indicating the ability of the cells to proliferate in the absence of estrogen. The combination of wortmannin with tamoxifen or fulvestrant inhibited tumor growth better than either drug alone. The combination of wortmannin plus fulvestrant was the most effective treatment that maintained tumor regression for a prolonged time. CONCLUSION: These results suggest that blocking both ER and growth factor receptor pathways could provide effective control over tumor growth of long-term estrogen-deprived human breast cancers.

Docetaxel followed by castration improves outcomes in LNCaP prostate cancer-bearing severe combined immunodeficient mice.

PURPOSE: Androgen ablation is the standard initial treatment for advanced prostate cancer; however, tumors eventually develop androgen independence and become incurable. Chemotherapy is commonly used after hormone treatment fails but has not shown significant survival benefit. Studies suggest that androgen ablation can select for a population of hormone-independent cells that are also relatively chemotherapy resistant. Thus, it may be therapeutically advantageous to target prostate cancer with chemotherapy before hormone ablation. This study was undertaken to determine the relative efficacy of such an approach in a preclinical model of prostate cancer. EXPERIMENTAL DESIGN: Severe combined immunodeficient mice bearing human LNCaP prostate tumors were treated with docetaxel and/or surgical castration applied singly, concurrently, or in different sequences. Treatment efficacy was determined by tumor volume and growth delay measurements. The extent of apoptosis in tumors in response to treatments was assessed via terminal deoxynucleotidyl transferase-mediated nick-end labeling (TUNEL) assays. In addition, Western blots were done to study the relative expression of Bcl-2 and Bax in the tumors. RESULTS: Docetaxel followed by castration showed the most potent antitumor effects. In contrast, with the exception of castration alone, castration followed by docetaxel produced the least antitumor activity. TUNEL assays confirmed that the density of apoptotic tumor cells was significantly greater for docetaxel followed by castration than for any other treatment. In tumors of mice treated with single modality therapies, Bax to Bcl-2 ratios decreased significantly after castration, whereas this ratio remained high after docetaxel treatment. CONCLUSION: A treatment sequence of docetaxel followed by hormone ablation may be more effective in treating prostate cancer than concurrent docetaxel/hormone therapy or hormone ablation followed by docetaxel.

The role of growth factor receptor pathways in human breast cancer cells adapted to long-term estrogen deprivation.

To study the long-term effects of estrogen deprivation on breast cancer, MCF-7Ca human estrogen receptor-positive breast cancer cells stably transfected with human aromatase gene were cultured in the steroid-depleted medium for 6 to 8 months until they had acquired the ability to grow. Proliferation of these cells (UMB-1Ca) was accompanied by increased expression of human epidermal growth factor receptor 2, increased activation of AKT through phosphorylation at Ser473 and Thr308, and increased invasion compared with parental MCF-7Ca cells. Estrogen receptor expression was also increased 5-fold. Although growth was inhibited by the antiestrogen fulvestrant, the IC50 was 100-fold higher than for parental MCF-7Ca cells. Aromatase inhibitor letrozole also inhibited growth at 10,000-fold higher concentration than required for MCF-7Ca cells, whereas anastrozole, exemestane, formestane, and tamoxifen were ineffective at 100 nmol/L. Growth of UMB-1Ca cells was inhibited by phosphatidylinositol 3-kinase inhibitor wortmannin (IC50 approximately 25 nmol/L) and epidermal growth factor receptor kinase inhibitor gefitinib (ZD 1839; IC50 approximately 10 micromol/L) whereas parental MCF-7Ca cells were insensitive to these agents. Concomitant treatment of UMB-1Ca cells with the signal transduction inhibitors and anastrozole and tamoxifen restored their growth inhibitory effects. These studies show that estrogen deprivation results in up-regulation of growth factor signaling pathways, which leads to a more aggressive and hormone refractory phenotype. Cross-talk between ER and growth factor signaling was evident as inhibition of these pathways could restore estrogen responsiveness to these cells.

Activation of mitogen-activated protein kinase in xenografts and cells during prolonged treatment with aromatase inhibitor letrozole.

Ovariectomized mice bearing tumor xenografts grown from aromatase-transfected estrogen receptor (ER)-positive human breast cancer cells (MCF-7Ca) were injected s.c. with 10 microg/d letrozole for up to 56 weeks. Western blot analysis of the tumors revealed that ERs (ERalpha) were increased at 4 weeks but decreased at weeks 28 and 56. Expression of erbB-2 and p-Shc increased throughout treatment, whereas growth factor receptor binding protein 2 (Grb2) increased only in tumors proliferating on letrozole (weeks 28 and 56). In cells isolated from tumors after 56 weeks and maintained as a cell line (LTLT-Ca) in 1 micromol/L letrozole, ERalpha was also decreased whereas erbB-2, adapter proteins (p-Shc and Grb2), and the signaling proteins in the mitogen-activated protein kinase (MAPK) cascade were increased compared with MCF-7Ca cells. Growth was inhibited in LTLT-Ca cells but not in MCF-7Ca cells treated with MAPK kinase 1/2 inhibitors U0126, and PD98059 (IC(50) approximately 25 micromol/L). PD98059 (5 micromol/L) also reduced MAPK activity and increased ERalpha to the levels in MCF-7Ca cells. Epidermal growth factor receptor kinase inhibitor, gefitinib (ZD1839) inhibited growth of LTLT-Ca cells (IC(50) approximately 10 micromol/L) and restored their sensitivity to tamoxifen and anastrozole. In xenografts, combined treatment with ER down-regulator fulvestrant and letrozole, prevented increases in erbB-2 and activation of MAPK and was highly effective in inhibiting tumor growth throughout 29 weeks of treatment. These results indicate that blocking both ER- and growth factor-mediated transcription resulted in the most effective inhibition of growth of ER-positive breast cancer cells.

Additive antitumor effect of aromatase inhibitor letrozole and antiestrogen fulvestrant in a postmenopausal breast cancer model.

Blocking estrogen receptors with antiestrogens and blocking estrogen synthesis with aromatase inhibitors are two strategies currently being used for reducing the effect of estrogen in postmenopausal estrogen receptor-positive breast cancer patients. To optimize these treatment strategies, we have investigated whether tumor progression can be delayed by combining the pure antiestrogen fulvestrant with the nonsteroidal aromatase inhibitor letrozole. These studies were done in ovariectomized, athymic mice bearing tumors of estrogen receptor-positive human breast cancer cells stably transfected with the aromatase gene (MCF-7Ca). Groups of mice with equivalent tumor volumes were injected s.c. daily with vehicle (control; n = 6), fulvestrant (1 mg/d; n = 7), letrozole (10 microg/d; n = 18), or letrozole (10 microg/d) plus fulvestrant (1 mg/d; n = 5). All treatments were effective in suppressing tumor growth compared with controls (P < 0.001). Tumor volumes of the fulvestrant-treated group had doubled in 10 weeks. After 19 weeks of letrozole (10 microg/d) treatment when tumors had nearly doubled in volume, mice (n = 18) were assigned to second-line therapy with letrozole (100 microg/d; n = 6), tamoxifen (100 microg/d; n = 6), or remained on letrozole treatment (10 microg/d; n = 6). However, tumors continued to increase in volume in these groups. Tumors of animals treated with the combination of letrozole plus Faslodex regressed over 29 weeks of treatment by 45%. Thus, the combination of letrozole plus fulvestrant was more effective in suppressing tumor growth than either letrozole or fulvestrant alone or sequential therapies with tamoxifen or a higher dose of letrozole (100 microg/d).

Therapeutic observations in MCF-7 aromatase xenografts.

In previous studies using a xenograft model with tumors of human estrogen receptor (ER)-positive breast cancer cells transfected with aromatase (MCF-7Ca), we explored the antitumor efficacy of treatment combining the nonsteroidal aromatase inhibitor letrozole with tamoxifen. However, treatment with this combination resulted in tumor suppression similar to tamoxifen alone but was less effective than letrozole alone. Clinical findings with the nonsteroidal inhibitor anastrozole in combination with tamoxifen (ATAC trial) were consistent with our results. Although letrozole was the most effective single agent in the model, tumors ultimately began to grow during continued treatment. To investigate the mechanisms by which tumors adapted to growth during letrozole treatment, we determined the expression of proteins in tumors during letrozole treatment compared with the tumors of control mice. We found that tumors initially up-regulated the ER, but subsequently receptor levels decreased in tumors unresponsive to letrozole. Adapter proteins (p-Shc and Grb-2) as well as all of the signaling proteins in the mitogen-activated protein kinase cascade (p-Raf, p-MEK1/2, and p-MAPK) but not Akt were increased in tumors no longer responsive to letrozole. The results suggest that tumor cells adapt to estrogen deprivation during letrozole treatment by activation of alternate signaling pathways. When letrozole was combined with the pure antiestrogen fulvestrant, which down-regulates ER, the combination was extremely effective. Tumors regressed by 45% and were maintained without growth for the duration of the experiment (29 weeks). Thus, achieving more complete estrogen blockade may delay development of hormone-independent signaling pathways regulating proliferation.

Prevalence of chemopreventive agent use among hospitalised women at high risk for breast cancer: a cross-sectional study.

OBJECTIVE: To characterise the current usage of chemoprevention agents among hospitalised women who are at higher risk for breast cancer. STUDY DESIGN: A cross-sectional study. SETTING: Academic hospital at Baltimore. PARTICIPANTS: A bedside survey of 250 women aged 50-75 years was conducted who were cancer-free at the time of study enrolment and hospitalised to a general medicine service. Reproductive history, family history for breast cancer, chemopreventive agents use and medical comorbidities data was collected for all patients. χ2 and t-tests were used to analyse population characteristics. PRIMARY OUTCOME MEASURES: Prevalence of women at high risk for developing breast cancer (5-year Gail risk score ≥1.7) and their chemopreventive agent use. RESULTS: Mean age for the study population was 61.5 years (SD 7.5), and mean 5-year Gail risk score was 1.67 (SD 0.88). A third of study population was at high risk for breast cancer. None of the high-risk women (0%) were taking chemoprevention for breast cancer risk reduction, and 23% were at very high risk with 5-year Gail score ≥3%. These women were not recognised as being high risk by their hospital providers and none were referred to the high-risk breast cancer clinics following discharge. CONCLUSIONS: Many hospitalised women are at high risk for breast cancer and we could not identify even a single woman who was using chemoprevention for risk reduction. Current chemoprevention guidelines may be falling short in their dissemination and implementation. Since women at high risk for breast cancer may only interface with the healthcare system at select points, all healthcare providers must be willing and able to do risk assessment. For those identified to be at high risk, providers must then either engage in chemopreventive counselling or refer patients to providers who are more comfortable working with patients on this critical decision.

Model systems: mechanisms involved in the loss of sensitivity to letrozole.

A number of models have been used to study the development and treatment of breast cancer. Since most breast cancer patients are postmenopausal and treated with hormone therapy, we developed a model to simulate this type of patient. Tumors of human estrogen receptor (ER)-positive breast cancer cells transfected with aromatase (MCF-7Ca) are grown in immune suppressed mice. In this model, we have explored a number of strategies to optimize the antitumor efficacy of treatment such as combining the non-steroidal aromatase inhibitor letrozole with the antiestrogens, tamoxifen. This combination resulted in tumor suppression similar to the antiestrogen alone, but was less effective than letrozole alone. Clinical findings with the non-steroidal inhibitor anastrozole in combination with tamoxifen (ATAC trial) were consistent with our results. Although letrozole was the most effective single agent tested in the model, tumors ultimately began to grow during continued treatment. To investigate the mechanisms by which tumors adapt to growth during letrozole treatment, we determined the expression of signaling proteins in tumors during the course of letrozole treatment compared to the tumors of control mice. We found that tumors initially up regulated the ER, but subsequently receptor levels decreased in tumors unresponsive to letrozole. Adapter proteins (p-Shc and Grb-2) as well as all of the signaling proteins in the MAPK cascade (p-Raf, p-Mek1/2, and p-MAPK), but not Akt, were increased in tumors no longer responsive to letrozole. The results suggest that tumor cells adapt to estrogen deprivation during letrozole treatment by activation of alternate signaling pathways to increase transcription. When letrozole was combined with the pure antiestrogen fulvestrant, to down regulate ER, the combination was more effective than either letrozole or fulvestrant alone. Tumors regressed by 45% and were maintained without growth for the duration of the experiment (29 weeks). Down regulation of ER by fulvestrant may prevent cross talk between these signaling pathways. The results suggest that achieving more complete estrogen blockade may delay development of hormone-independent signaling pathways regulating proliferation.

Predictions from a preclinical model: studies of aromatase inhibitors and antiestrogens.

We have developed a tumor model for studying the effects of aromatase inhibitors and antiestrogens in vivo. The model simulates postmenopausal breast cancer patients with estrogen-dependent tumors. This model utilizes human estrogen-dependent breast cancer cells transfected with the aromatase gene (MCF-7(CA)), which are inoculated in Matrigel s.c. into ovariectomized nude mice. The estrogen receptor-positive cells produce sufficient estrogen by aromatization to stimulate their proliferation and the formation of tumors in the mice. Using several different strategies, we have compared the aromatase inhibitors (letrozole and anastrozole) with antiestrogens (tamoxifen and fulvestrant). Aromatase inhibitors were more effective than tamoxifen and were more effective alone than when combined with antiestrogens. In addition, letrozole had a longer duration of effect than tamoxifen. The possibility of delaying the development of resistance to antiestrogens and aromatase inhibitors was investigated by alternating letrozole with tamoxifen every 4 weeks. However, although alternating treatment proved more effective than tamoxifen alone (tumors doubled in 16 weeks), tumors doubled in volume at about 18 weeks when treatment began with tamoxifen. When treatment started with letrozole and alternated with tamoxifen, tumors doubled in volume in about 22 weeks. However, tumors of mice treated with letrozole alone did not double in size until 35 weeks. These results demonstrate that this aromatase inhibitor is more effective and has a longer duration of response as a single agent than tamoxifen or in combination with tamoxifen.