Expression of dihydropyrimidine dehydrogenase (DPD) and hENT1 predicts survival in pancreatic cancer.

BACKGROUND: Dihydropyrimidine dehydrogenase (DPD) tumour expression may provide added value to human equilibrative nucleoside transporter-1 (hENT1) tumour expression in predicting survival following pyrimidine-based adjuvant chemotherapy. METHODS: DPD and hENT1 immunohistochemistry and scoring was completed on tumour cores from 238 patients with pancreatic cancer in the ESPAC-3(v2) trial, randomised to either postoperative gemcitabine or 5-fluorouracil/folinic acid (5FU/FA). RESULTS: DPD tumour expression was associated with reduced overall survival (hazard ratio, HR = 1.73 [95% confidence interval, CI = 1.21-2.49], p = 0.003). This was significant in the 5FU/FA arm (HR = 2.07 [95% CI = 1.22-3.53], p = 0.007), but not in the gemcitabine arm (HR = 1.47 [0.91-3.37], p = 0.119). High hENT1 tumour expression was associated with increased survival in gemcitabine treated (HR = 0.56 [0.38-0.82], p = 0.003) but not in 5FU/FA treated patients (HR = 1.19 [0.80-1.78], p = 0.390). In patients with low hENT1 tumour expression, high DPD tumour expression was associated with a worse median [95% CI] survival in the 5FU/FA arm (9.7 [5.3-30.4] vs 29.2 [19.5-41.9] months, p = 0.002) but not in the gemcitabine arm (14.0 [9.1-15.7] vs. 18.0 [7.6-15.3] months, p = 1.000). The interaction of treatment arm and DPD expression was not significant (p = 0.303), but the interaction of treatment arm and hENT1 expression was (p = 0.009). CONCLUSION: DPD tumour expression was a negative prognostic biomarker. Together with tumour expression of hENT1, DPD tumour expression defined patient subgroups that might benefit from either postoperative 5FU/FA or gemcitabine.

Intratumoural expression of deoxycytidylate deaminase or ribonuceotide reductase subunit M1 expression are not related to survival in patients with resected pancreatic cancer given adjuvant chemotherapy.

BACKGROUND: Deoxycytidylate deaminase (DCTD) and ribonucleotide reductase subunit M1 (RRM1) are potential prognostic and predictive biomarkers for pyrimidine-based chemotherapy in pancreatic adenocarcinoma. METHODS: Immunohistochemical staining of DCTD and RRM1 was performed on tissue microarrays representing tumour samples from 303 patients in European Study Group for Pancreatic Cancer (ESPAC)-randomised adjuvant trials following pancreatic resection, 272 of whom had received gemcitabine or 5-fluorouracil with folinic acid in ESPAC-3(v2), and 31 patients from the combined ESPAC-3(v1) and ESPAC-1 post-operative pure observational groups. RESULTS: Neither log-rank testing on dichotomised strata or Cox proportional hazard regression showed any relationship of DCTD or RRM1 expression levels to survival overall or by treatment group. CONCLUSIONS: Expression of either DCTD or RRM1 was not prognostic or predictive in patients with pancreatic adenocarcinoma who had had post-operative chemotherapy with either gemcitabine or 5-fluorouracil with folinic acid.

Meta-analysis of individual patient safety data from six randomized, placebo-controlled trials with the antiangiogenic VEGFR2-binding monoclonal antibody ramucirumab.

BACKGROUND: Ramucirumab, the human immunoglobulin G1 monoclonal antibody receptor antagonist of vascular endothelial growth factor receptor 2, has been approved for treating gastric/gastroesophageal junction, non-small-cell lung, and metastatic colorectal cancers. With the completion of six global, randomized, double-blind, placebo-controlled, phase III trials across multiple tumor types, an opportunity now exists to further establish the safety parameters of ramucirumab across a large patient population. MATERIALS AND METHODS: An individual patient meta-analysis across the six completed phase III trials was conducted and the relative risk (RR) and associated 95% confidence intervals (CIs) were derived using fixed-effects or mixed-effects models for all-grade and high-grade adverse events (AEs) possibly related to vascular endothelial growth factor pathway inhibition. The number needed to harm was also calculable due to the placebo-controlled nature of all six registration standard trials. RESULTS: A total of 4996 treated patients (N = 2748 in the ramucirumab arm and N = 2248 in the control, placebo arm) were included in this meta-analysis. Arterial thromboembolic events [ATE; all-grade, RR: 0.8, 95% CI 0.5-1.3; high-grade (grade ≥3), RR: 0.9, 95% CI 0.5-1.7], venous thromboembolic events (VTE; all-grade, RR: 0.7, 95% CI 0.5-1.1; high-grade, RR: 0.7, 95% CI 0.4-1.2), high-grade bleeding (RR: 1.1, 95% CI 0.8-1.5), and high-grade gastrointestinal (GI) bleeding (RR: 1.1, 95% CI 0.7-1.7) did not demonstrate a definite increased risk with ramucirumab. A higher percentage of hypertension, proteinuria, low-grade (grade 1-2) bleeding, GI perforation, infusion-related reaction, and wound-healing complications were observed in the ramucirumab arm compared with the control arm. CONCLUSIONS: Ramucirumab may be distinct among antiangiogenic agents in terms of ATE, VTE, high-grade bleeding, or high-grade GI bleeding by showing no clear evidence for an increased risk of these AEs in this meta-analysis of a large and diverse patient population. Ramucirumab is consistent with other angiogenic inhibitors in the risk of developing certain AEs. Clinical Trial Numbers: NCT00917384 (REGARD), NCT01170663 (RAINBOW), NCT01168973 (REVEL), NCT01183780 (RAISE), NCT01140347 (REACH), and NCT00703326 (ROSE).

Beta blockers and improved progression-free survival in patients with advanced HER2 negative breast cancer: a retrospective analysis of the ROSE/TRIO-012 study.

BACKGROUND: Recent retrospective studies suggest that beta-adrenergic blocking drugs (BB) are associated with improved outcomes in patients with a range of cancers. Although limited and discordant data suggest that BB may increase overall survival (OS) in localized breast cancer (BC), there is no information on the effects of BB in women with advanced BC. PATIENTS AND METHODS: To explore the association between BB use and BC outcomes, we retrospectively reviewed ROSE/TRIO-012, a double-blinded, multinational phase III trial that randomized 1144 patients with HER2-negative advanced BC to first-line docetaxel in combination with ramucirumab or placebo. We compared progression-free survival (PFS), OS, overall response rate, and clinical benefit rate in patients who received BB to those who did not. RESULTS: 153/1144 (13%) patients received BB; 62% prior to enrolment and 38% began after enrolment. Median PFS in BB treated patients was longer than in patients who did not receive them (10.3 versus 8.3 months; HR 0.81; 95% CI 0.66-0.99; P = 0.038). Patients treated with BB only after enrolment had even higher median PFS (15.5 versus 8.3 months, P < 0.001). In the TNBC subset, median PFS was 13.0 months with BB, compared to 5.2 months without BB (HR 0.52; 95% CI 0.34-0.79; P = 0.002). The benefit of BB intake in PFS was independent of treatment-emergent hypertension (P = 0.476) but associated with treatment arm (P = 0.037). The test for interactions between BB and treatment arm was not significant (P = 0.276). No differences were seen in OS, overall response rate, or clinical benefit rate. A validation dataset analysis had consistent but less substantial improved outcomes for women with node positive operable breast cancer receiving BB in the BCIRG-005 trial. CONCLUSIONS: In this exploratory analysis, BB intake was associated with significant improvement in PFS, particularly in patients with TNBC and patients not previously exposed to BB. CLINICAL TRIAL NUMBER: NCT00703326.

Long-term outcomes after adjuvant treatment of sequential versus combination docetaxel with doxorubicin and cyclophosphamide in node-positive breast cancer: BCIRG-005 randomized trial.

BACKGROUND: The optimal regimen for adjuvant breast cancer chemotherapy is undefined. We compared sequential to concurrent combination of doxorubicin and cyclophosphamide with docetaxel chemotherapy in women with node-positive non-metastatic breast cancer. We report the final, 10-year analysis of disease-free survival (DFS), overall survival (OS), and long-term safety. PATIENTS AND METHODS: A total of 3298 women with HER2 nonamplified breast cancer were randomized to doxorubicin and cyclophosphamide every 3 weeks for four cycles followed by docetaxel (AC → T) every 3 weeks for four cycles or docetaxel, doxorubicin, and cyclophosphamide (TAC) every 3 weeks for six cycles. The patients received standard radiotherapy and endocrine therapy and were followed up for 10 years with annual clinical evaluation and mammography. RESULTS: The 10-year DFS rates were 66.5% in the AC → T arm and 66.3% in the TAC arm (P = 0.749). OS was 79.9% in the AC → T arm and 78.9% in the TAC arm (P = 0.506). TAC was associated with higher rates of febrile neutropenia, although G-CSF primary prophylaxis greatly reduced this risk. AC → T was associated with a higher rate of myalgia, hand-foot syndrome, fluid retention, and sensory neuropathy. CONCLUSION: This 10-year analysis of the BCIRG-005 trial confirmed that the efficacy of TAC was not superior to AC → T in women with node-positive early breast cancer. The toxicity profiles differ between arms and were consistent with previous reports. The TAC regimen with G-CSF support provides shorter adjuvant treatment duration with less toxicity. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT00312208.

Effect of aerobic training on the host systemic milieu in patients with solid tumours: an exploratory correlative study.

BACKGROUND: Few studies have investigated the effects of exercise on modulation of host factors in cancer patients. We investigated the efficacy of chronic aerobic training on multiple host-related effector pathways in patients with solid tumours. PATIENTS AND METHODS: Paired peripheral blood samples were obtained from 44 patients with solid tumours receiving cytotoxic therapy and synthetic erythropoietin (usual care; n=21) or usual care plus supervised aerobic training (n=23) for 12 weeks. Samples were characterised for changes in immune, cytokine and angiogenic factors, and metabolic intermediates. Aerobic training consisted of three supervised cycle ergometry sessions per week at 60% to 100% of peak oxygen consumption (VO2peak), 30-45 min per session, for 12 weeks following a nonlinear prescription. RESULTS: The between-group delta change in cardiopulmonary function was +4.1 ml kg (-1) min(-1), favouring aerobic training (P<0.05). Significant pre-post between-group differences for five cytokine and angiogenic factors (HGF, IL-4, macrophage inflammatory protein-1ß (MIP-1ß), vascular endothelial growth factor (VEGF), and TNF-α) also favour the aerobic training group (P's<0.05). These reductions occurred in conjunction with nonsignificant group differences for T lymphocytes CD4(+), CD8(+), and CD8(+)/CD45RA (P<0.10). For these factors, circulating concentrations generally increased from baseline to week 12 in the aerobic training group compared with decreases or no change in the usual care group. No significant changes in any metabolic intermediates were observed. CONCLUSIONS: Aerobic training alters host availability of select immune-inflammatory effectors in patients with solid tumours; larger confirmatory studies in more homogenous samples are warranted.

Subgroup effects in a randomised trial of different types and doses of exercise during breast cancer chemotherapy.

BACKGROUND: The Combined Aerobic and Resistance Exercise Trial tested different types and doses of exercise in breast cancer patients receiving chemotherapy. Here, we explore potential moderators of the exercise training responses. METHODS: Breast cancer patients initiating chemotherapy (N=301) were randomly assigned to three times a week, supervised exercise of a standard dose of 25-30 min of aerobic exercise, a higher dose of 50-60 min of aerobic exercise, or a higher dose of 50-60 min of combined aerobic and resistance exercise. Outcomes were patient-reported symptoms and health-related fitness. Moderators were baseline demographic, exercise/fitness, and cancer variables. RESULTS: Body mass index moderated the effects of the exercise interventions on bodily pain (P for interaction=0.038), endocrine symptoms (P for interaction=0.029), taxane/neuropathy symptoms (P for interaction=0.013), aerobic fitness (P for interaction=0.041), muscular strength (P for interaction=0.007), and fat mass (P for interaction=0.005). In general, healthy weight patients responded better to the higher-dose exercise interventions than overweight/obese patients. Menopausal status, age, and baseline fitness moderated the effects on patient-reported symptoms. Premenopausal, younger, and fitter patients achieved greater benefits from the higher-dose exercise interventions. CONCLUSIONS: Healthy weight, fitter, and premenopausal/younger breast cancer patients receiving chemotherapy are more likely to benefit from higher-dose exercise interventions.

Targeting triple-negative breast cancer: optimising therapeutic outcomes.

BACKGROUND: Triple-negative breast cancer (TNBC) is a distinct subset of breast cancer (BC) defined by the lack of immunohistochemical expression of the estrogen and progesterone receptors and human epidermal growth factor receptor 2. It is highly heterogeneous and displays overlapping characteristics with both basal-like and BC susceptibility gene 1 and 2 mutant BCs. This review evaluates the activity of emerging targeted agents in TNBC. DESIGN: A systematic review of PubMed and conference databases was carried out to identify randomised clinical trials reporting outcomes in women with TNBC treated with targeted and platinum-based therapies. RESULTS AND DISCUSSION: Our review identified TNBC studies of agents with different mechanisms of action, including induction of synthetic lethality and inhibition of angiogenesis, growth, and survival pathways. Combining targeted agents with chemotherapy in TNBC produced only modest gains in progression-free survival, and had little impact on survival. Six TNBC subgroups have been identified and found to differentially respond to specific targeted agents. The use of biological preselection to guide therapy will improve therapeutic indices in target-bearing populations. CONCLUSION: Ongoing clinical trials of targeted agents in unselected TNBC populations have yet to produce substantial improvements in outcomes, and advancements will depend on their development in target-selected populations.

Regulation of subcellular distribution and oncogenic potential of nucleophosmin by plakoglobin.

Nucleophosmin (NPM) is a nucleolar phosphoprotein that is involved in many cellular processes and has both oncogenic and growth suppressing activities. NPM is localized primarily in nucleoli but shuttles between the nucleus and the cytoplasm, and sustained cytoplasmic distribution contributes to its tumor promoting activities. Plakoglobin (PG, γ-catenin) is a homolog of ß-catenin with dual adhesive and signaling functions. These proteins interact with cadherins and mediate adhesion, while their signaling activities are regulated by association with various intracellular partners. Despite these similarities, ß-catenin has a well-defined oncogenic activity, whereas PG acts as a tumor/metastasis suppressor through unknown mechanisms. Comparison of the proteomic profiles of carcinoma cell lines with low- or no PG expression with their PG-expressing transfectants has identified NPM as being upregulated upon PG expression. Here, we examined NPM subcellular distribution and in vitro tumorigenesis/metastasis in the highly invasive and very low PG expressing MDA-MB-231 (MDA-231) breast cancer cells and their transfectants expressing increased PG (MDA-231-PG) or NPM shRNA (MDA-231-NPM-KD) or both (MDA-231-NPM-KD+PG). Increased PG expression increased the levels of nucleolar NPM and coimmunoprecipitation studies showed that NPM interacts with PG. PG expression or NPM knockdown decreased the growth rate of MDA-231 cells substantially and this reduction was decreased further in MDA-231-NPM-KD+PG cells. In in vitro tumorigenesis/metastasis assays, MDA-231-PG cells showed substantially lower and MDA-231-NPM-KD cells substantially higher invasiveness relative to the MDA-231 parental cells, and the co-expression of PG and NPM shRNA led to even further reduction of the invasiveness of MDA-231-PG cells. Furthermore, examination of the levels and localization of PG and NPM in primary biopsies of metastatic infiltrating ductal carcinomas revealed coordinated expression of PG and NPM. Together, the data suggest that PG may regulate NPM subcellular distribution, which may potentially change the function of the NPM protein from oncogenic to tumor suppression.

Human equilibrative nucleoside transporter 1 and carcinoma of the ampulla of Vater: expression differences in tumour histotypes.

The human equilibrative nucleoside transporter 1 (hENT1) is the major means by which gemcitabine enters human cells; recent evidence exists that hENT1 is expressed in carcinoma of the ampulla of Vater and that it should be considered as a molecular prognostic marker for patients with resected ampullary cancer. Aim of the present study is to evaluate the variations of hENT1 expression in ampullary carcinomas and to correlate such variations with histological subtypes and clinicopathological parameters. Forty-one ampullary carcinomas were histologically classified into intestinal, pancreaticobiliary and unusual types. hENT1 and Ki67 expression were evaluated by immunohistochemistry, and apoptotic cells were identified by the terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate biotin nick end labelling (TUNEL) method. hENT1 overexpression was detected in 63.4% ampullary carcinomas. A significant difference in terms of hENT1 and Ki67 expression was found between intestinal vs. pancreaticobiliary types (P=0.03 and P=0.009 respectively). Moreover, a significant statistical positive correlation was found between apoptotic and proliferative Index (P=0.036), while no significant correlation was found between hENT1 and apoptosis. Our results on hENT1 expression suggest that classification of ampullary carcinoma by morphological subtypes may represent an additional tool in prospective clinical trials aimed at examining treatment efficacy; in addition, data obtained from Ki67 and TUNEL suggest a key role of hENT1 in tumour growth of ampullary carcinoma.

The BH3-only protein Bad confers breast cancer taxane sensitivity through a nonapoptotic mechanism.

Antimitotic agents such as taxanes (paclitaxel and docetaxel) have greatly advanced the treatment of breast cancer, although variable patient response and drug toxicity are major limitations. Lack of validated predictive markers for taxane responsiveness precludes a priori identification of patients who are most likely to respond to treatment; thus, a subset of patients endure toxic side effects with marginal benefit. Mechanistic insights into taxane therapeutic activity may lead to rational therapeutic improvements. In this paper we report that the proapoptotic BH3-only protein Bad has a major role in taxane-induced cell death in vitro, and clinically is a prognostic indicator for overall survival of breast cancer patients after adjuvant taxane chemotherapy. Unexpectedly, Bad did not induce the mitochondrial apoptotic machinery in response to taxane treatment. Instead, Bad indirectly facilitated cell death by stimulating cellular proliferation. As dividing cells are the targets of taxane therapy, Bad-stimulated proliferation may be a marker of taxane sensitivity. Our studies indicate that quantification of Bad protein levels may have value as a diagnostic tool. They also suggest that cells expressing Bad are more sensitive to taxanes because of their altered cell cycle dynamics and reveal a clinically relevant proliferative role of Bad in breast cancer.

Metabolic modulation of glioblastoma with dichloroacetate.

Solid tumors, including the aggressive primary brain cancer glioblastoma multiforme, develop resistance to cell death, in part as a result of a switch from mitochondrial oxidative phosphorylation to cytoplasmic glycolysis. This metabolic remodeling is accompanied by mitochondrial hyperpolarization. We tested whether the small-molecule and orphan drug dichloroacetate (DCA) can reverse this cancer-specific metabolic and mitochondrial remodeling in glioblastoma. Freshly isolated glioblastomas from 49 patients showed mitochondrial hyperpolarization, which was rapidly reversed by DCA. In a separate experiment with five patients who had glioblastoma, we prospectively secured baseline and serial tumor tissue, developed patient-specific cell lines of glioblastoma and putative glioblastoma stem cells (CD133(+), nestin(+) cells), and treated each patient with oral DCA for up to 15 months. DCA depolarized mitochondria, increased mitochondrial reactive oxygen species, and induced apoptosis in GBM cells, as well as in putative GBM stem cells, both in vitro and in vivo. DCA therapy also inhibited the hypoxia-inducible factor-1alpha, promoted p53 activation, and suppressed angiogenesis both in vivo and in vitro. The dose-limiting toxicity was a dose-dependent, reversible peripheral neuropathy, and there was no hematologic, hepatic, renal, or cardiac toxicity. Indications of clinical efficacy were present at a dose that did not cause peripheral neuropathy and at serum concentrations of DCA sufficient to inhibit the target enzyme of DCA, pyruvate dehydrogenase kinase II, which was highly expressed in all glioblastomas. Metabolic modulation may be a viable therapeutic approach in the treatment of glioblastoma.

Plakoglobin interacts with and increases the protein levels of metastasis suppressor Nm23-H2 and regulates the expression of Nm23-H1.

Plakoglobin (gamma-catenin) is a homolog of beta-catenin with similar dual adhesive and signaling functions. The adhesive function of these proteins is mediated by their interactions with cadherins, whereas their signaling activity is regulated by association with various intracellular partners. In this respect, beta-catenin has a well-defined oncogenic activity through its role in the Wnt signaling pathway, whereas plakoglobin acts as a tumor/metastasis suppressor through mechanisms that remain unclear. We previously expressed plakoglobin in SCC9 squamous carcinoma cells (SCC9-P) and observed a mesenchymal-to-epidermoid transition. Comparison of the protein and RNA profiles of parental SCC9 cells and SCC9-P transfectants identified various differentially expressed proteins and transcripts, including the nonmetastatic protein 23 (Nm23). In this study, we show that Nm23-H1 mRNA and Nm23-H2 protein are increased after plakoglobin expression. Coimmunoprecipitation and confocal microscopy studies using SCC9-P and various epithelial cell lines with endogenous plakoglobin expression revealed that Nm23 interacts with plakoglobin, cadherins and alpha-catenin. Furthermore, Nm23-H2 is the primary isoform involved in these interactions, which occur prominently in the cytoskeleton-associated pool of cellular proteins. In addition, we show that plakoglobin-Nm23 interaction requires the N-terminal (alpha-catenin interacting) domain of plakoglobin. Our data suggest that by increasing the expression and stability of Nm23, plakoglobin has a role in regulating the metastasis suppressor activity of Nm23, which may further provide a potential mechanism for the tumor/metastasis suppressor function of plakoglobin itself.

Dichloroacetate (DCA) as a potential metabolic-targeting therapy for cancer.

The unique metabolism of most solid tumours (aerobic glycolysis, i.e., Warburg effect) is not only the basis of diagnosing cancer with metabolic imaging but might also be associated with the resistance to apoptosis that characterises cancer. The glycolytic phenotype in cancer appears to be the common denominator of diverse molecular abnormalities in cancer and may be associated with a (potentially reversible) suppression of mitochondrial function. The generic drug dichloroacetate is an orally available small molecule that, by inhibiting the pyruvate dehydrogenase kinase, increases the flux of pyruvate into the mitochondria, promoting glucose oxidation over glycolysis. This reverses the suppressed mitochondrial apoptosis in cancer and results in suppression of tumour growth in vitro and in vivo. Here, we review the scientific and clinical rationale supporting the rapid translation of this promising metabolic modulator in early-phase cancer clinical trials.

Cardiac management during adjuvant trastuzumab therapy: recommendations of the Canadian Trastuzumab Working Group.

Trastuzumab has been shown to be an effective therapy for women with breast cancer that overexpresses the human epidermal growth factor receptor 2 (her2) protein. In the pivotal metastatic breast cancer trials, cardiac dysfunction was observed in women treated with trastuzumab and chemotherapy. The incidence and severity of cardiac dysfunction was greatest among patients who received trastuzumab in combination with anthracycline-based therapy. Those findings influenced the design of subsequent trastuzumab trials to include prospective evaluations of cardiac effects and protocols for cardiac monitoring and management. The risk of cardiotoxicity has also driven efforts to develop non-anthracycline-based regimens for women with her2-positive breast cancers.With the increasing use of trastuzumab, particularly in the curative adjuvant setting, the need for a rational approach to the treatment and cardiac management of the relevant patient population is clear. The mandate of the Canadian Trastuzumab Working Group was to formulate recommendations, based on available data, for the assessment and management of cardiac complications during adjuvant trastuzumab therapy. The panel formulated recommendations in four areas: Risk factors for cardiotoxicity, Effects of various regimens, Monitoring, Management. The recommendations published here are expected to evolve as more data become available and experience with trastuzumab in the adjuvant setting grows.

Human equilibrative nucleoside transporter 1 (hENT1) protein is associated with short survival in resected ampullary cancer.

BACKGROUND: Gemcitabine is an acceptable alternative to best supportive care in the treatment of advanced biliary tract cancers. The human equilibrative nucleoside transporter 1 (hENT1) is a ubiquitous protein and is the major means by which gemcitabine enters human cells. Moreover, recent reports indicate a significant correlation between immunohistochemical variations of hENT1 in tumor samples and survival after gemcitabine therapy in patients with solid tumors. MATERIALS AND METHODS: We used immunohistochemistry to assess the abundance and distribution of hENT1 in tumor samples from radically resected cancer of the ampulla, and sought correlations between immunohistochemical results and clinical parameters including disease outcomes. RESULTS: In the 41 individual tumors studied, 12 (29.3%) had uniformly high hENT1 immunostaining. Statistical analysis showed a significant correlation between hENT1 and Ki-67 (P = 0.04). No statistical significant differences were found between immunohistochemical findings and patient characteristics (sex, age, and tumor-node-metastasis). On univariate analysis, hENT1 and Ki-67 expression were associated with overall survival (OS). Specifically, those patients with overexpression of hENT1 showed a shorter OS (P = 0.022) and those with high Ki-67 staining showed a shorter survival (P = 0.05). CONCLUSIONS: hENT1 expression is a molecular prognostic marker for patients with resected ampullary cancer and holds promise as a predictive factor to assist in chemotherapy decisions.

Adjuvant trastuzumab: progress, controversies, and the steps ahead.

The major breast cancer story of 2005 was trastuzumab, a monoclonal antibody directed against the Her-2 oncoprotein, and how it greatly improves outcomes for women with HER2-positive early-stage breast cancer. With early results showing that use of the drug can prevent roughly one half of relapses, adjuvant trastuzumab has been approved, funded, and accepted as the standard of care in many Canadian jurisdictions. In the present brief report, we summarize the four major adjuvant trials, outline some key controversies, and suggest steps to provide more-effective and better-tolerated adjuvant systemic therapy for the relevant patient subgroup.

Mechanisms of uptake and resistance to troxacitabine, a novel deoxycytidine nucleoside analogue, in human leukemic and solid tumor cell lines.

Troxacitabine (Troxatyl; BCH-4556; (-)-2'-deoxy-3'-oxacytidine), a deoxycytidine analogue with an unusual dioxolane structure and nonnatural L-configuration, has potent antitumor activity in animal models and is in clinical trials against human malignancies. The current work was undertaken to identify potential biochemical mechanisms of resistance to troxacitabine and to determine whether there are differences in resistance mechanisms between troxacitabine, gemcitabine, and cytarabine in human leukemic and solid tumor cell lines. The CCRF-CEM leukemia cell line was highly sensitive to the antiproliferative effects of troxacitabine, gemcitabine, and cytarabine with inhibition of proliferation by 50% observed at 160, 20, and 10 nM, respectively, whereas a deoxycytidine kinase (dCK)-deficient variant (CEM/dCK(-)) was resistant to all three drugs. In contrast, a nucleoside transport-deficient variant (CEM/ARAC8C) exhibited high levels of resistance to cytarabine (1150-fold) and gemcitabine (432-fold) but only minimal resistance to troxacitabine (7-fold). Analysis of troxacitabine transportability by the five molecularly characterized human nucleoside transporters [human equilibrative nucleoside transporters 1 and 2, human concentrative nucleoside transporter (hCNT) 1, hCNT2, and hCNT3] revealed that short- and long-term uptake of 10-30 microM [(3)H]troxacitabine was low and unaffected by the presence of either nucleoside transport inhibitors or high concentrations of nonradioactive troxacitabine. These results, which suggested that the major route of cellular uptake of troxacitabine was passive diffusion, demonstrated that deficiencies in nucleoside transport were unlikely to impart resistance to troxacitabine. A troxacitabine-resistant prostate cancer subline (DU145(R); 6300-fold) that exhibited reduced uptake of troxacitabine was cross-resistant to both gemcitabine (350-fold) and cytarabine (300-fold). dCK activity toward deoxycytidine in DU145(R) cell lysates was <20% of that in DU145 cell lysates, and no activity was detected toward troxacitabine. Sequence analysis of cDNAs encoding dCK revealed a mutation of a highly conserved amino acid (Trp(92)-->Leu) in DU145(R) dCK, providing a possible explanation for the reduced phosphorylation of troxacitabine in DU145(R) lysates. Reduced deamination of deoxycytidine was also observed in DU145(R) relative to DU145 cells, and this may have contributed to the overall resistance phenotype. These results, which demonstrated a different resistance profile for troxacitabine, gemcitabine, and cytarabine, suggest that troxacitabine may have an advantage over gemcitabine and cytarabine in human malignancies that lack or have low nucleoside transport activities.