Charles L. Shapiro

MicroRNA-221/222 Confers Tamoxifen Resistance in Breast Cancer by Targeting p27Kip1

We explored the role of microRNAs (miRNAs) in acquiring resistance to tamoxifen, a drug successfully used to treat women with estrogen receptor-positive breast cancer. miRNA microarray analysis of MCF-7 cell lines that are either sensitive (parental) or resistant (4-hydroxytamoxifen-resistant (OHTR)) to tamoxifen showed significant (>1.8-fold) up-regulation of eight miRNAs and marked down-regulation (>50%) of seven miRNAs in OHTR cells compared with parental MCF-7 cells. Increased expression of three of the most promising up-regulated (miR-221, miR-222, and miR-181) and down-regulated (miR-21, miR-342, and miR-489) miRNAs was validated by real-time reverse transcription-PCR. The expression of miR-221 and miR-222 was also significantly (2-fold) elevated in HER2/neu-positive primary human breast cancer tissues that are known to be resistant to endocrine therapy compared with HER2/neu-negative tissue samples. Ectopic expression of miR-221/222 rendered the parental MCF-7 cells resistant to tamoxifen. The protein level of the cell cycle inhibitor p27Kip1, a known target of miR-221/222, was reduced by 50% in OHTR cells and by 28–50% in miR-221/222-overexpressing MCF-7 cells. Furthermore, overexpression of p27Kip1 in the resistant OHTR cells caused enhanced cell death when exposed to tamoxifen. This is the first study demonstrating a relationship between miR-221/222 expression and HER2/neu overexpression in primary breast tumors that are generally resistant to tamoxifen therapy. This finding also provides the rationale for the application of altered expression of specific miRNAs as a predictive tamoxifen-resistant breast cancer marker.

American Society of Clinical Oncology Clinical Evidence Review on the Ongoing Care of Adult Cancer Survivors: Cardiac and Pulmonary Late Effects

PURPOSE To review the evidence on the incidence of long-term cardiac or pulmonary toxicity secondary to chemotherapy, radiotherapy, or trastuzumab in symptomatic and asymptomatic cancer survivors. METHODS An American Society of Clinical Oncology Panel reviewed pertinent information from the literature through February 2006. RESULTS Few studies directly addressing the benefits of screening for long-term cardiac or pulmonary toxicity in asymptomatic cancer survivors who received chemotherapy, radiotherapy, or trastuzumab were identified. The reviewed literature included primarily retrospective and cross-sectional studies describing the incidence of cardiac and pulmonary late effects. Anatomic and/or functional abnormalities have been associated with use of all currently available anthracyclines and their derivatives. Trastuzumab-related cardiac dysfunction rarely causes death, and in most cases is reversible with improvement in cardiac function on drug discontinuation and/or treatment with cardiac medications. The estimated aggregate incidence of radiation-induced cardiac disease is 10% to 30% by 5 to 10 years post-treatment, although the incidence may be lower with modern techniques. Radiation pneumonitis is reported in 5% to 15% of lung cancer patients receiving definitive external-beam radiation therapy. A minority of patients may develop progressive pulmonary fibrosis; late complications include cor pulmonale and respiratory failure. Bleomycin-induced pneumonitis is an acute rather than late effect of treatment. Late pulmonary complications in bone marrow or stem cell transplantation patients who develop interstitial pneumonitis include idiopathic pneumonia syndrome and bronchiolitis obliterans. CONCLUSION An increased incidence of cardiac and/or pulmonary dysfunction is observed in cancer survivors. Research is needed to identify high-risk patients, and to determine the optimal screening strategies and subsequent treatment.

Randomized Phase III Trial of Weekly Compared With Every-3-Weeks Paclitaxel for Metastatic Breast Cancer, With Trastuzumab for all HER-2 Overexpressors and Random Assignment to Trastuzumab or Not in HER-2 Nonoverexpressors: Final Results of Cancer and Leukemia Group B Protocol 9840

PURPOSE Phase II trials suggested that weekly paclitaxel might be more effective and less toxic than every-3-weeks administration for metastatic breast cancer (MBC). Cancer and Leukemia Group B (CALGB) protocol 9840 was initiated to address this question. Subsequently trastuzumab was demonstrated to improve outcomes of paclitaxel therapy for human epidermal growth factor receptor-2 (HER-2)-positive patients, and was therefore incorporated. Because inhibition of HER-family signaling had potential efficacy even without HER-2 overexpression, we randomly assigned for trastuzumab in this population. PATIENTS AND METHODS Patients were randomly assigned to paclitaxel 175 mg/m(2) every 3 weeks or 80 mg/m(2) weekly. After the first 171 patients, all HER-2-positive patients received trastuzumab; HER-2 nonoverexpressors were randomly assigned for trastuzumab, in addition to paclitaxel schedule. A total of 577 patients were treated on 9840. An additional 158 patients were included in analyses, for combined sample of 735. The primary end point was response rate (RR); secondary end points were time to progression (TTP), overall survival, and toxicity. Primary comparisons were between weekly versus every-3-weeks paclitaxel, and trastuzumab versus no trastuzumab in HER-2 nonoverexpressors. RESULTS In the combined sample, weekly paclitaxel was superior to every-3-weeks administration: RR (42% v 29%, unadjusted odds ratio [OR] = 1.75; P = .0004), TTP (median, 9 v 5 months; adjusted HR = 1.43; P < .0001), and survival (median, 24 v 12 months; adjusted HR = 1.28; P = .0092). For HER-2 nonoverexpressors, trastuzumab did not improve efficacy. Grade 3 neuropathy was more common with weekly dosing (24% v 12%; P = .0003). CONCLUSION Weekly paclitaxel is more effective than every-3-weeks administration for MBC. Trastuzumab did not improve efficacy for HER-2 nonoverexpressors. Neurotoxicity is a treatment-limiting toxicity for weekly paclitaxel.

Ovarian failure after adjuvant chemotherapy is associated with rapid bone loss in women with early-stage breast cancer

PURPOSE We sought to evaluate the effects of chemotherapy-induced ovarian failure on bone loss and markers of skeletal turnover in a prospective longitudinal study of young women with breast cancer receiving adjuvant chemotherapy. PATIENTS AND METHODS Forty-nine premenopausal women with stage I/II breast cancers receiving adjuvant chemotherapy were evaluated within 4 weeks of starting chemotherapy (baseline), and 6 and 12 months after starting chemotherapy with dual-energy absorptiometry and markers of skeletal turnover osteocalcin and bone-specific alkaline phosphatase. Chemotherapy-induced ovarian failure was defined as a negative pregnancy test, greater than 3 months of amenorrhea, and a follicle-stimulating hormone > or = 30 MIU/mL at the 12-month evaluation. RESULTS Among the 35 women who were defined as having ovarian failure, highly significant bone loss was observed in the lumbar spine by 6 months and increased further at 12 months. The median percentage decrease of bone mineral density in the spine from 0 to 6 months and 6 to 12 months was -4.0 (range, -10.4 to +1.0; P =.0001) and -3.7 (range, -10.1 to 9.2; P =.0001), respectively. In contrast, there were no significant decreases in bone mineral density in the 14 patients who retained ovarian function. Serum osteocalcin and bone specific alkaline phosphatase, markers of skeletal turnover, increased significantly in the women who developed ovarian failure. CONCLUSION Chemotherapy-induced ovarian failure causes rapid and highly significant bone loss in the spine. This may have implications for long-term breast cancer survivors who may be at higher risk for osteopenia, and subsequently osteoporosis. Women with breast cancer who develop chemotherapy-induced ovarian failure should have their bone density monitored and treatments to attenuate bone loss should be evaluated.

Psychological, Behavioral, and Immune Changes After a Psychological Intervention: A Clinical Trial

PURPOSE This randomized clinical trial tests the hypothesis that a psychological intervention can reduce emotional distress, improve health behaviors and dose-intensity, and enhance immune responses. PATIENTS AND METHODS We studied 227 women who were surgically treated for regional breast cancer. Before adjuvant therapy, women completed interviews and questionnaires assessing emotional distress, social adjustment, and health behaviors. A 60-mL blood sample was drawn for immune assays. Patients were randomly assigned to either the intervention group or assessment only group. The intervention was conducted in small patient groups, with one session per week for 4 months. The sessions included strategies to reduce stress, improve mood, alter health behaviors, and maintain adherence to cancer treatment and care. Reassessment occurred after completion of the intervention. RESULTS As predicted, patients receiving the intervention showed significant lowering of anxiety, improvements in perceived social support, improved dietary habits, and reduction in smoking (all P <.05). Analyses of adjuvant chemotherapy dose-intensity revealed significantly more variability (ie, more dispersion in the dose-intensity values) for the assessment arm (P <.05). Immune responses for the intervention patients paralleled their psychological and behavioral improvements. T-cell proliferation in response to phytohemagglutinin and concanavalin A remained stable or increased for the Intervention patients, whereas both responses declined for Assessment patients; this effect was replicated across three concentrations for each assay (all P <.01). CONCLUSION These data show a convergence of significant psychological, health behavior, and biologic effects after a psychological intervention for cancer patients.

Cardiac effects of adjuvant doxorubicin and radiation therapy in breast cancer patients.

PURPOSE To assess the cardiac effects of two different cumulative doses of adjuvant doxorubicin and radiation therapy (RT) in breast cancer patients. PATIENTS AND METHODS Two hundred ninety-nine breast cancer patients were prospectively randomized to receive either five cycles (CA5) or 10 cycles (CA10) of adjuvant treatment with cyclophosphamide (500 mg/ m2) and doxorubicin (45 mg/m2) administered by intravenous bolus every 21 days. One hundred twenty-two of these patients also received RT. Estimates of the cardiac RT dose-volume were retrospectively categorized as low, moderate, or high. The risk of major cardiac events (congestive heart failure, acute myocardial infarction) was assessable in 276 patients (92%), with a median follow-up time of 6.0 years (range, 0.5 to 19.4). RESULTS The estimated risk (95% confidence interval) of cardiac events per 100 patient-years was significantly higher for CA10 than for CA5 [1.7 (1.0 to 2.8) v 0.5 (0.1 to 1.2); P=.02]. The risk of cardiac events in CA5 patients, irrespective of the cardiac RT dose-volume, did not differ significantly from rates of cardiac events predicted for the general female population by the Framingham Heart Study. In CA10 patients, the incidence of cardiac events was significantly increased (relative risk ratio, 3.6; P < .00003) compared with the Framingham population, particularly in groups that also received moderate and high dose-volume cardiac RT. CONCLUSION Conventional-dose adjuvant doxorubicin as delivered in the CA5 regimen by itself, or in combination with locoregional RT, was not associated with a significant increase in the risk of cardiac events. Higher doses of adjuvant doxorubicin (CA10) were associated with a threefold to fourfold increased risk of cardiac events. This appears to be especially true in patients treated with higher dose-volumes of cardiac RT. Larger studies with longer follow-up periods are needed to confirm these results.

Inherited Mutations in 17 Breast Cancer Susceptibility Genes Among a Large Triple-Negative Breast Cancer Cohort Unselected for Family History of Breast Cancer

PURPOSE Recent advances in DNA sequencing have led to the development of breast cancer susceptibility gene panels for germline genetic testing of patients. We assessed the frequency of mutations in 17 predisposition genes, including BRCA1 and BRCA2, in a large cohort of patients with triple-negative breast cancer (TNBC) unselected for family history of breast or ovarian cancer to determine the utility of germline genetic testing for those with TNBC. PATIENTS AND METHODS Patients with TNBC (N = 1,824) unselected for family history of breast or ovarian cancer were recruited through 12 studies, and germline DNA was sequenced to identify mutations. RESULTS Deleterious mutations were identified in 14.6% of all patients. Of these, 11.2% had mutations in the BRCA1 (8.5%) and BRCA2 (2.7%) genes. Deleterious mutations in 15 other predisposition genes were detected in 3.7% of patients, with the majority observed in genes involved in homologous recombination, including PALB2 (1.2%) and BARD1, RAD51D, RAD51C, and BRIP1 (0.3% to 0.5%). Patients with TNBC with mutations were diagnosed at an earlier age (P < .001) and had higher-grade tumors (P = .01) than those without mutations. CONCLUSION Deleterious mutations in predisposition genes are present at high frequency in patients with TNBC unselected for family history of cancer. Mutation prevalence estimates suggest that patients with TNBC, regardless of age at diagnosis or family history of cancer, should be considered for germline genetic testing of BRCA1 and BRCA2. Although mutations in other predisposition genes are observed among patients with TNBC, better cancer risk estimates are needed before these mutations are used for clinical risk assessment in relatives.

Mapping Geographic Zones of Cancer Risk with Epigenetic Biomarkers in Normal Breast Tissue

Purpose: Genetic alterations were previously identified in normal epithelia adjacent to invasive cancers. The aim of this study was to determine DNA methylation in histologically normal tissues from multiple geographic zones adjacent to primary breast tumors. Experimental Design: First, methylation status of a 4-kb region of RASSF1A promoter was interrogated using oligonucleotide-based microarray in 144 samples (primary tumors, 47; adjacent normals, 69; reduction mammoplasty tissues, 28). Second, allelic imbalance (AI)/loss of heterozygosity (LOH) surrounding RASSF1A promoter were analyzed in 30 samples (tumors, 8; adjacent normals, 22). Third, global methylation screening of 49 samples (tumors, 12; adjacent normals, 25; reduction mammoplasty, 12) was done by differential methylation hybridization. Real-time quantitative methylation-specific PCR was used to validate the microarray findings. Results: DNA methylation in the core RASSF1A promoter was low in reduction mammoplasty tissues (P = 0.0001) when compared with primary tumors. The adjacent normals had an intermediate level of methylation. The regions surrounding the core were highly methylated in all sample types. Microsatellite markers showed AI/LOH in tumors and some of the adjacent normals. Concurrent AI/LOH and DNA methylation in RASSF1A promoter occurred in two of six tumors. Global methylation screening uncovered genes more methylated in adjacent normals than in reduction mammoplasty tissues. The methylation status of four genes was confirmed by quantitative methylation-specific PCR. Conclusions: Our findings suggest a field of methylation changes extending as far as 4 cm from primary tumors. These frequent alterations may explain why normal tissues are at risk for local recurrence and are useful in disease prognostication.

Phase II Trial of Bevacizumab in Combination with Weekly Docetaxel in Metastatic Breast Cancer Patients

Purpose: To evaluate the safety and efficacy of bevacizumab and weekly docetaxel as first- or second-line therapy in patients with metastatic breast cancer (MBC). Patients and Methods: Twenty-seven MBC patients received i.v. bevacizumab at 10 mg/kg on days 1 and 15 in combination with i.v. docetaxel 35 mg/m2 on days 1, 8, and 15 of a 28-day cycle. Primary end points were to assess toxicity, overall response rate, and progression-free survival. A secondary end point was to assess the relationship between plasma endothelial and cell adhesion markers and clinical outcomes. Results: One-hundred fifty-eight treatment cycles were administered with a median of six cycles (range 1-15 cycles) per patient. The most common grade 4 toxicities per patient were as follows: 2 (7%)—pulmonary embolus, 1 (4%)—febrile neutropenia, and 1 (4%)—infection; grade 3 toxicities were 4 (15%)—neutropenia, 4 (15%)—fatigue, 2 (7%)—neuropathy, 2 (7%)—athralgias, 2 (7%)—stomatitis, 1 (7%)—pleural effusion, and 1 (4%)—hypertension. The overall response rate was 52% [95% confidence interval (95% CI), 32-71%], median response duration was 6.0 months (95% CI, 4.6-6.5 months), and the median progression-free survival was 7.5 months (95% CI, 6.2-8.3 months). In hypothesis-generating univariate and limited multivariate analyses, E-selectin was statistically significantly associated with response to the combination. Conclusion: Bevazicumab in combination with weekly docetaxel is active with acceptable toxicities in MBC. Additional studies evaluating E-selectin as a marker of response to bevacizumab-containing chemotherapy are warranted.

Hedgehog Signaling Is a Novel Therapeutic Target in Tamoxifen-Resistant Breast Cancer Aberrantly Activated by PI3K/AKT Pathway

Endocrine resistance is a major challenge in the management of estrogen receptor (ER)-positive breast cancers. Although multiple mechanisms leading to endocrine resistance have been proposed, the poor outcome of patients developing resistance to endocrine therapy warrants additional studies. Here we show that noncanonical Hedgehog (Hh) signaling is an alternative growth promoting mechanism that is activated in tamoxifen-resistant tumors. Importantly, phosphoinositide 3-kinase inhibitor/protein kinase B (PI3K/AKT) pathway plays a key role in regulating Hh signaling by protecting key components of this pathway from proteasomal degradation. The levels of Hh-signaling molecules SMO and GLI1 and the targets were significantly elevated in tamoxifen-resistant MCF-7 cells and T47D cells. Serial passage of the resistant cells in mice resulted in aggressive tumors that metastasized to distant organs with concurrent increases in Hh marker expression and epithelial mesenchymal transition. RNAi-mediated depletion of SMO or GLI1 in the resistant cells resulted in reduced proliferation, clonogenic survival and delayed G(1)-S transition. Notably, treatment of resistant cells with PI3K inhibitors decreased SMO and GLI1 protein levels and activity that was rescued upon blocking GSK3β and proteasomal degradation. Furthermore, treatment of tamoxifen-resistant xenografts with anti-Hh compound GDC-0449 blocked tumor growth in mice. Importantly, high GLI1 expression correlated inversely with disease-free and overall survival in a cohort of 315 patients with breast cancer. In summary, our results describe a signaling event linking PI3K/AKT pathway with Hh signaling that promotes tamoxifen resistance. Targeting Hh pathway alone or in combination with PI3K/AKT pathway could therefore be a novel therapeutic option in treating endocrine-resistant breast cancer.