Johan W.R. Nortier

Effects of Epoetin Alfa on Hematologic Parameters and Quality of Life in Cancer Patients Receiving Nonplatinum Chemotherapy: Results of a Randomized, Double-Blind, Placebo-Controlled Trial

PURPOSE This randomized, double-blind, placebo-controlled clinical trial assessed the effects of epoetin alfa on transfusion requirements, hematopoietic parameters, quality of life (QOL), and safety in anemic cancer patients receiving nonplatinum chemotherapy. The study also explored a possible relationship between increased hemoglobin and survival. PATIENTS AND METHODS Three hundred seventy-five patients with solid or nonmyeloid hematologic malignancies and hemoglobin levels < or = 10.5 g/dL, or greater than 10.5 g/dL but < or = 12.0 g/dL after a hemoglobin decrease of > or = 1.5 g/dL per cycle since starting chemotherapy, were randomized 2:1 to epoetin alfa 150 to 300 IU/kg (n = 251) or placebo (n = 124) three times per week subcutaneously for 12 to 24 weeks. The primary end point was proportion of patients transfused; secondary end points were change in hemoglobin and QOL. The protocol was amended before unblinding to prospectively collect and assess survival data 12 months after the last patient completed the study. RESULTS Epoetin alfa, compared with placebo, significantly decreased transfusion requirements (P =.0057) and increased hemoglobin (P <.001). Improvement of all primary cancer- and anemia-specific QOL domains, including energy level, ability to do daily activities, and fatigue, was significantly (P <.01) greater for epoetin alfa versus placebo patients. Although the study was not powered for survival as an end point, Kaplan-Meier estimates showed a trend in overall survival favoring epoetin alfa (P =.13, log-rank test), and Cox regression analysis showed an estimated hazards ratio of 1.309 (P =.052) favoring epoetin alfa. Adverse events were comparable between groups. CONCLUSION Epoetin alfa safely and effectively ameliorates anemia and significantly improves QOL in cancer patients receiving nonplatinum chemotherapy. Encouraging results regarding increased survival warrant another trial designed to confirm these findings.

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.

Aromatase and COX-2 expression in human breast cancers☆

We have investigated aromatase and the inducible cyclooxygenase COX-2 expression using immunocytochemistry in tumors of a series of patients with advanced breast cancer treated with aromatase inhibitors. Aromatase was expressed in 58/102 breast cancers. This is similar to the percentage previously reported for aromatase activity. Interestingly, aromatase was expressed in a variety of cell types, including tumor, stromal, adipose, and endothelial cells. Since prostaglandin E2 is known to regulate aromatase gene expression and is the product of COX-2, an enzyme frequently overexpressed in tumors, immunocytochemistry was performed on the tissue sections using a polyclonal antibody to COX-2. Aromatase was strongly correlated (P<0.001) with COX-2 expression. These results suggest that PGE2 produced by COX-2 in the tumor may be important in stimulating estrogen synthesis in the tumor and surrounding tissue. No correlation was observed between aromatase or COX-2 expression and the response of the patients to aromatase inhibitor treatment. However, only 13 patients responded. Nine of these patients were aromatase positive. Although similar to responses in other studies, this low response rate to second line treatment suggests that tumors of most patients were no longer sensitive to the effects of estrogen. Recent clinical studies suggest that greater responses occur when aromatase inhibitors are used as first line treatment. In the intratumoral aromatase mouse model, expression of aromatase in tumors is highly correlated with increased tumor growth. First line treatment with letrozole was effective in all animals treated and was more effective than tamoxifen in suppressing tumor growth. Letrozole was also effective in tumors failing to respond to tamoxifen, consistent with clinical findings. In addition, the duration of response was significantly longer with the aromatase inhibitor than with tamoxifen, suggesting that aromatase inhibitors may offer better control of tumor growth than this antiestrogen.

Effect of Concomitant CYP2D6 Inhibitor Use and Tamoxifen Adherence on Breast Cancer Recurrence in Early-Stage Breast Cancer

PURPOSE The use of cytochrome P450 2D6-inhibiting drugs (CYP2D6 inhibitors) during tamoxifen treatment leads to a decrease in plasma concentration of endoxifen, the major active tamoxifen metabolite. Concomitant use of CYP2D6 inhibitors, such as selective serotonin reuptake inhibitors, as well as low tamoxifen adherence may negatively impact tamoxifen efficacy in patients with breast cancer. The objectives of this study were to relate concomitant CYP2D6 inhibitor use and tamoxifen adherence to breast cancer event-free time (EFT). PATIENTS AND METHODS Data were from PHARMO and included a community pharmacy dispensing database; PALGA, a nationwide pathology database; and the Dutch Medical Register in the Netherlands. Patients with breast cancer treated with adjuvant tamoxifen between 1994 and 2006 were included. A Cox proportional hazards model with a time-dependent definition for concomitant CYP2D6 inhibitor exposure was used. Adherence calculated over the first year after tamoxifen initiation was related to breast cancer events in the following period. RESULTS In total, 1,962 patients with breast cancer using tamoxifen were included, among whom 150 (7.6%) frequently used a CYP2D6 inhibitor during tamoxifen treatment. No association between concomitant CYP2D6 inhibitor use and breast cancer recurrence was observed (adjusted hazard ratio [HR], 0.87; 95% CI, 0.42 to 1.79; P = .69). Poor tamoxifen adherence was associated with lower EFT (adjusted HR, 0.987; 95% CI, 0.975 to 0.999; P = .029). CONCLUSION This observational study did not show an association between concomitant CYP2D6 inhibitor use and breast cancer recurrence among patients treated with adjuvant tamoxifen despite the strong biologic rationale. This study shows, to the best of our knowledge for the first time, that poor tamoxifen adherence is associated with an increased risk of breast cancer events.

Small Molecule Tyrosine Kinase Inhibitors in the Treatment of Solid Tumors: An Update of Recent Developments

Small molecule tyrosine kinase inhibitors (TKIs) are developed to block intracellular signaling pathways in tumor cells, leading to deregulation of key cell functions such as proliferation and differentiation. Over 25 years ago, tyrosine kinases were found to function as oncogenes in animal carcinogenesis; however, only recently TKIs were introduced as anti cancer drugs in human cancer treatment. Tyrosine kinase inhibitors have numerous good qualities. First, in many tumor types they tend to stabilize tumor progression and may create a chronic disease state which is no longer immediately life threatening. Second, side effects are minimal when compared to conventional chemotherapeutic agents. Third, synergistic effects are seen in vitro when TKIs are combined with radiotherapy and/or conventional chemotherapeutic agents. In this article, we will give an update of the tyrosine kinase inhibitors that are currently registered for use or in an advanced stage of development, and we will discuss the future role of TKIs in the treatment of solid tumors. The following TKIs are reviewed: Imatinib (Gleevec/Glivec), Gefitinib (Iressa), Erlotinib (OSI-774, Tarceva), Lapatinib (GW-572016, Tykerb), Canertinib (CI-1033), Sunitinib (SU 11248, Sutent), Zactima (ZD6474), Vatalanib (PTK787/ZK 222584), Sorafenib (Bay 43-9006, Nexavar), and Leflunomide (SU101, Arava).

Association Between Age at Diagnosis and Disease-Specific Mortality Among Postmenopausal Women With Hormone Receptor–Positive Breast Cancer

CONTEXT In addition to classic tumor-related prognostic factors, patient characteristics may be associated with breast cancer outcome. OBJECTIVE To assess the association between age at diagnosis and breast cancer outcome in postmenopausal women with hormone receptor-positive breast cancer. DESIGN, SETTING, AND PATIENTS Study analysis of 9766 patients enrolled in the TEAM (Tamoxifen Exemestane Adjuvant Multinational) randomized clinical trial between January 2001 and January 2006. Age at diagnosis was categorized as younger than 65 years (n=5349), 65 to 74 years (n=3060), and 75 years or older (n=1357). MAIN OUTCOME MEASURES Primary end point was disease-specific mortality; secondary end points were other-cause mortality and breast cancer relapse. RESULTS During median follow-up of approximately 5.1 years, there were a total of 1043 deaths. Disease-specific mortality, as a proportion of all-cause mortality, decreased with categorical age group (78% [<65 years], 56% [65-74 years], and 36% [≥75 years]; P < .001). In multivariable analyses, compared with patients younger than 65 years, disease-specific mortality increased with age for patients aged 65 to 74 years (hazard ratio [HR], 1.25; 95% CI, 1.01-1.54); and patients aged 75 years or older (HR, 1.63; 95% CI, 1.23-2.16) (P < .001). Similarly, breast cancer relapse increased with age for patients aged 65-74 years (HR, 1.07; 95% CI, 0.91-1.25 and patients aged 75 years or older (HR, 1.29; 95% CI, 1.05-1.60) (P = .06). Other-cause mortality increased with age in patients aged 65 to 74 years (HR, 2.66; 95% CI, 1.96-3.63) and patients aged 75 years or older (HR, 7.30; 95% CI, 5.29-10.07) (P < .001). CONCLUSION Among postmenopausal women with hormone receptor-positive breast cancer, increasing age was associated with a higher disease-specific mortality.

Chemotherapy Alters Monocyte Differentiation to Favor Generation of Cancer-Supporting M2 Macrophages in the Tumor Microenvironment

Current therapy of gynecologic malignancies consists of platinum-containing chemotherapy. Resistance to therapy is associated with increased levels of interleukin (IL)-6 and prostaglandin E2 (PGE(2)), 2 inflammatory mediators known to skew differentiation of monocytes to tumor-promoting M2 macrophages. We investigated the impact of cisplatin and carboplatin on 10 different cervical and ovarian cancer cell lines as well as on the ability of the tumor cells to affect the differentiation and function of cocultured monocytes in vitro. Treatment with cisplatin or carboplatin increased the potency of tumor cell lines to induce IL-10-producing M2 macrophages, which displayed increased levels of activated STAT3 due to tumor-produced IL-6 as well as decreased levels of activated STAT1 and STAT6 related to the PGE(2) production of tumor cells. Blockade of canonical NF-κB signaling showed that the effect of the chemotherapy was abrogated, preventing the subsequent increased production of PGE(2) and/or IL-6 by the tumor cell lines. Treatment with the COX-inhibitor indomethacin and/or the clinical monoclonal antibody against interleukin-6 receptor (IL-6R), tocilizumab, prevented M2-differentiation. Importantly, no correlation existed between the production of PGE(2) or IL-6 by cancer cells and their resistance to chemotherapy-induced cell death, indicating that other mechanisms underlie the reported chemoresistance of tumors producing these factors. Our data suggest that a chemotherapy-mediated increase in tumor-promoting M2 macrophages may form an indirect mechanism for chemoresistance. Hence, concomitant therapy with COX inhibitors and/or IL-6R antibodies might increase the clinical effect of platinum-based chemotherapy in otherwise resistant tumors.

Downregulation of Homologous Recombination DNA Repair Genes by HDAC Inhibition in Prostate Cancer Is Mediated through the E2F1 Transcription Factor

Background Histone deacetylase inhibitors (HDACis) re-express silenced tumor suppressor genes and are currently undergoing clinical trials. Although HDACis have been known to induce gene expression, an equal number of genes are downregulated upon HDAC inhibition. The mechanism behind this downregulation remains unclear. Here we provide evidence that several DNA repair genes are downregulated by HDAC inhibition and provide a mechanism involving the E2F1 transcription factor in the process. Methodology/Principal Findings Applying Analysis of Functional Annotation (AFA) on microarray data of prostate cancer cells treated with HDACis, we found a number of genes of the DNA damage response and repair pathways are downregulated by HDACis. AFA revealed enrichment of homologous recombination (HR) DNA repair genes of the BRCA1 pathway, as well as genes regulated by the E2F1 transcription factor. Prostate cancer cells demonstrated a decreased DNA repair capacity and an increased sensitization to chemical- and radio-DNA damaging agents upon HDAC inhibition. Recruitment of key HR repair proteins to the site of DNA damage, as well as HR repair capacity was compromised upon HDACi treatment. Based on our AFA data, we hypothesized that the E2F transcription factors may play a role in the downregulation of key repair genes upon HDAC inhibition in prostate cancer cells. ChIP analysis and luciferase assays reveal that the downregulation of key repair genes is mediated through decreased recruitment of the E2F1 transcription factor and not through active repression by repressive E2Fs. Conclusions/Significance Our study indicates that several genes in the DNA repair pathway are affected upon HDAC inhibition. Downregulation of the repair genes is on account of a decrease in amount and promoter recruitment of the E2F1 transcription factor. Since HDAC inhibition affects several pathways that could potentially have an impact on DNA repair, compromised DNA repair upon HDAC inhibition could also be attributed to several other pathways besides the ones investigated in this study. However, our study does provide insights into the mechanism that governs downregulation of HR DNA repair genes upon HDAC inhibition, which can lead to rationale usage of HDACis in the clinics.

Phase I Pharmacokinetic and Pharmacodynamic Study of the Aurora Kinase Inhibitor Danusertib in Patients With Advanced or Metastatic Solid Tumors

PURPOSE Danusertib (PHA-739358) is a small-molecule pan-aurora kinase inhibitor. This phase I dose escalation study was conducted to evaluate safety and tolerability of danusertib with additional pharmacokinetic, biomarker, and efficacy assessments. PATIENTS AND METHODS Patients with solid tumors refractory to standard therapies or with no standard therapy available were enrolled. Danusertib was administered intravenously on days 1, 8, and 15 every 28 days in 6-hour or 3-hour infusion schedules (ie, 6-hour IVS or 3-hour IVS). Dose levels from 45 mg/m(2) in the 6-hour IVS, and from 250 mg/m(2) in the 3-hour IVS, were studied. RESULTS Fifty patients were treated. For the 6-hour IVS, the most frequently reported adverse effects were neutropenia (55%), nausea (25%), anorexia (23%), fatigue (20%), and diarrhea (18%). In the 3-hour IVS, fatigue (70%), neutropenia (60%), diarrhea (50%), and nausea (30%) were seen. Nonhematologic toxicity was mild to moderate. Neutropenia was dose limiting. The maximum-tolerated dose was 330 mg/m(2) for the 6-hour IVS and was not identified for the 3-hour IVS. The systemic exposure to danusertib increased linearly with dose. The infusion rate did not appear to remarkably influence the pharmacokinetics of danusertib. Biomarker analysis showed inhibition of histone H3 phosphorylation, indicative of aurora B inhibition, at doses of 190 mg/m(2) or greater. Stable disease was observed in 23.7% of evaluable patients, and disease stabilization occurred in 6 or more months in five patients. CONCLUSION Dose-limiting toxicity of danusertib is neutropenia, which was short lasting and generally uncomplicated; danusertib administration had limited nonhematologic toxicity. The recommended dose of danusertib for phase II studies is 330 mg/m(2) infused over 6 hours on days 1, 8, and 15 every 28 days.

Clinical Implications of CYP2D6 Genotyping in Tamoxifen Treatment for Breast Cancer

In October 2006 the Food and Drug Administration recommended an update in the tamoxifen label to reflect the increased risk of recurrence in breast cancer patients who are cytochrome P450 2D6 (CYP2D6) poor metabolizers. This recommendation was based on only a few studies at that time. More clinical studies addressing the relation between the CYP2D6 genotype and tamoxifen efficacy have been published since, mostly describing Caucasian populations in the adjuvant treatment setting. An updated analysis of the literature is presented. Furthermore, the possibility to implement CYP2D6 genotyping in clinical practice is evaluated by analyzing the results of six studies on mainly Caucasian patients using adjuvant tamoxifen. Three studies were consistent with the FDA advice, but the three other studies showed contradictory results. Although some of the published criticism on the negative studies is justified, this does not imply that these results should be discarded. The reviewed literature is put in perspective acknowledging the limiting effect of Mendelian randomization on confounding and the limitations of the various study designs. The current accumulation of data showing worse clinical outcome in patients with decreased CYP2D6 metabolism in other types of populations still indicates that the CYP2D6 genotype may well become a clinically relevant predictive marker. The CYP2D6 genotype might be one of the first predictors of therapeutic response in cancer care based on germline DNA creating the possibility to analyze blood instead of tumor.