A combined kinetic and modeling study of the catalytic center subsites of human angiogenin.

Kinetic analysis and molecular modeling have been used to map the ribonucleolytic center of angiogenin (Ang). Pyrimidine nucleotides were found to interact very weakly with Ang, consistent with the inaccessible B1 pyrimidine binding site revealed by x-ray crystallography. Ang also lacks an effective phosphate binding site on the 5' side of B1. Although the B2 site that preferentially binds purines on the 3' side of B1 is also weak, its associated phosphate subsites make substantial contributions: both 3',5'-ADP and 5'-ADP have Ki values 6-fold lower than for 5'-AMP, and adding a 3'-phosphate to the substrate CpA increases Kcat/Km by 9-fold. Thus Ang has a functional P2 site on the 3' side of B2 and a site for a second phosphate on the 5' side of B2. Modeling of an Ang-d(ApTpApA) complex suggested that Arg-5 forms part of the P2 site and that a 2'-phosphate might bind more tightly than a 3'-phosphate. Both predictions were confirmed kinetically. The subsite map obtained by this combined approach indicated that 5'-diphosphoadenosine 2'-phosphate might be a more potent inhibitor than any of the nucleotides tested thus far. Indeed, its Ki value of 150 microM is 50-fold lower than that for the best nucleotide previously reported and 400-fold lower than the Km for the best dinucleotide substrate. This compound may serve as a suitable starting point for the eventual design of tight-binding inhibitors of Ang as antiangiogenic agents for human therapy.

Disabilities, justice and the new eugenics of gene therapy

Eugenics is a difficult matter for discussion because, even as a term, it has fallen into disrepute. Yet a eugenic mindset pervades the discourses of reproduction and genetics in the West. I utilise the futures scenario of gene therapy to explore conceptually how the intersecting trajectories of science and religion make a new eugenics possible. The problematic of an inherent elitism within these sources, combined with a quest for power, leads me to renew the call for an adequate moral space within which to explore the requirements of social justice.

The effect of hormone replacement therapy and/or exercise on skeletal muscle attenuation in postmenopausal women: a yearlong intervention

Hormone replacement therapy (HRT) has been reported to exert a positive effect on preserving muscle strength following the menopause, however, the mechanism of action remains unclear. We examined whether the mechanism involved preservation of muscle composition as determined by skeletal muscle attenuation. Eighty women aged 50-57 years were randomly assigned to either: HRT, exercise (Ex), HRT + exercise (ExHRT), and control (Co) for 1 year. The study was double-blinded with subjects receiving oestradiol and norethisterone acetate (Kliogest) or placebo. Exercise included progressive high-impact training for the lower limbs. Skeletal muscle attenuation in Hounsfield units (HU) was determined by computed tomography of the mid-thigh. Areas examined were the quadriceps compartment (includes intermuscular adipose tissue), quadriceps muscles, the posterior compartment and posterior muscles. Muscle performance was determined by knee extensor strength, vertical jump height, and running speed over 20 m. Fifty-one women completed the intervention. Vertical jump height and running speed improved in the HRT and ExHRT groups compared with Co (interaction, P < 0.01). For both the quadriceps compartment and quadriceps muscles, HU significantly increased (interaction, P <= 0.005) for HRT, Ex, and ExHRT compared with Co. For the posterior compartment, HU for the HRT and ExHRT were significantly increased compared with Co, while for posterior muscles, ExHRT was significantly greater than Co. Although the effects were modest, the results indicate that HRT, either alone or combined with exercise, may play a role in preserving/improving skeletal muscle attenuation in early postmenopausal women and thereby exert a positive effect on muscle performance.

Hormones down under: Hormone therapy use after the women's health initiative

Aims: The primary objective was to describe the usage pattern of hormone therapy (HT) in a sample of urban Australian women in 2001 and to assess the characteristics of users vs. non-users. The second objective was to determine whether there had been any change in usage since the publication of the results of the combined oestrogen plus progestagen arm of the Women's Health Initiative (WHI) in 2002. Methods: A cohort of 374 postmenopausal women aged 50-80 years participated in this substudy of the LAW (Longitudinal Assessment of Ageing in Women) project: a 5-year multidisciplinary, observational study. Participants completed an annual medical assessment including details of the use of HT and the reasons for use, as well as demographic and psychosocial data. Results: In December 2001, 30.8% of the participants were using HT, whereas 55.4% were ever users. The management of vasomotor symptoms and mood disturbance were the primary reasons for use. Of those who had been using HT in December 2001 (24.4%) women ceased using HT in the 3 months following publication of the WHI results. The percentage of women using HT in December 2003 (13.9%) was less than half of that of December 2001. Conclusion: The rate of HT use and the reasons for use, in 2001 in Brisbane was similar to that of other Australian regions. Usage of HT decreased since the publication of the WHI results in 2002 which may reflect changing attitudes by patients and practitioners regarding HT.

Levonorgestrel intrauterine system versus medical therapy for menorrhagia

Background - Menorrhagia is a common problem, yet evidence to inform decisions about therapy is limited. In a pragmatic, multicenter, randomized trial, we compared the levonorgestrel-releasing intrauterine system (levonorgestrel-IUS) with usual medical treatment in women with menorrhagia who presented to their primary care providers. Methods - We randomly assigned 571 women with menorrhagia to treatment with levonorgestrel-IUS or usual medical treatment (tranexamic acid, mefenamic acid, combined estrogen–progestogen, or progesterone alone). The primary outcome was the patient-reported score on the Menorrhagia Multi-Attribute Scale (MMAS) (ranging from 0 to 100, with lower scores indicating greater severity), assessed over a 2-year period. Secondary outcomes included general quality-of-life and sexual-activity scores and surgical intervention. Results - MMAS scores improved from baseline to 6 months in both the levonorgestrel-IUS group and the usual-treatment group (mean increase, 32.7 and 21.4 points, respectively; P<0.001 for both comparisons). The improvements were maintained over a 2-year period but were significantly greater in the levonorgestrel-IUS group than in the usual-treatment group (mean between-group difference, 13.4 points; 95% confidence interval, 9.9 to 16.9; P<0.001). Improvements in all MMAS domains (practical difficulties, social life, family life, work and daily routine, psychological well-being, and physical health) were significantly greater in the levonorgestrel-IUS group than in the usual-treatment group, and this was also true for seven of the eight quality-of-life domains. At 2 years, more of the women were still using the levonorgestrel-IUS than were undergoing the usual medical treatment (64% vs. 38%, P<0.001). There were no significant between-group differences in the rates of surgical intervention or sexual-activity scores. There were no significant differences in serious adverse events between groups. Conclusions - In women with menorrhagia who presented to primary care providers, the levonorgestrel-IUS was more effective than usual medical treatment in reducing the effect of heavy menstrual bleeding on quality of life. (Funded by the National Institute of Health Research Health Technology Assessment Programme; ECLIPSE Controlled-Trials.com number, ISRCTN86566246.)

Levonorgestrel intrauterine system versus medical therapy for menorrhagia

ABSTRACT: Menorrhagia is a common problem that interferes with a woman’s physical, emotional, and social life. Evidence to guide physicians for decision about therapy for heavy menstrual bleeding is lacking. One treatment option, the levonorgestrel-releasing intrauterine system (levonorgestrel-IUS), has been available in the United States since 2009. Updated meta-analyses comparing the levonorgestrel-IUS with nonhormonal and hormonal treatments showed that the levonorgestrel-IUS produced a greater reduction in menstrual blood loss at 3 to 12 months of follow-up. It is not clear whether these short-term benefits persist. Moreover, the rates of discontinuation of the levonorgestrel-IUS at 2 years are as high as 28%, and effects on bleeding-related quality of life are not known. This pragmatic, multicenter, randomized trial compared the effectiveness of the levonorgestrel-IUS with that of usual medical treatment among women with menorrhagia in a primary care setting. A total of 571 women with menorrhagia were randomized to treatment with levonorgestrel-IUS (n = 285) or usual medical treatment (n = 286). Usual treatment was tranexamic acid, mefenamic acid, combined estrogen-progestogen, or progesterone alone. The primary study outcome measure was the patient-reported score on the condition-specific Menorrhagia Multi-Attribute Scale (MMAS) assessed over a 2-year period. The MMAS scores range from 0 to 100, with lower scores indicating greater severity. Summary MMAS scores were assessed at 6, 12, and 24 months. Secondary outcome measures included general health-related quality of life, sexual-activity scores, and surgical intervention. There was a significant improvement in total MMAS scores from baseline to 6 months in both the levonorgestrel-IUS group and the usual-treatment group; the mean increase was 32.7 and 21.4 points, respectively; P < 0.001 for both comparisons. Over the 2-year follow-up, improvements were maintained in both groups but were significantly greater in the levonorgestrel-IUS group (mean between-group difference, 13.4 points; 95% confidence interval, 9.9–16.9; P < 0.001). Significantly greater improvements in all MMAS domains (practical difficulties, social life, psychological health, physical health, work and daily routine, and family life and relationships) occurred with the levonorgestrel-IUS than with the usual treatment (P < 0.001 with the use of a test for trend). This was also found for 7 of the 8 quality-of-life domains. At the 2-year end point, almost twice as many women were still using the levonorgestrel-IUS than were those receiving the usual medical treatment (64% vs 38%, P < 0.001). No significant between-group differences were noted in the rates of surgical intervention or sexual-activity scores as well as in the frequency of serious adverse events. These data show that levonorgestrel-IUS is more effective than usual medical treatment in improving the quality of life of women with menorrhagia in a primary care setting.

Memantine combined with an acetyl cholinesterase inhibitor:hope for the future?

Background:Memantine and cholinesterase inhibitors (ChEI) have distinct pharmacological actions, and interest in the use of combination therapy for Alzheimer's disease (AD) is increasing. Objective: To assess the available data on the use of memantine–ChEI combination and to develop evidence-based recommendations.Method: A systematic literature review with detailed discussion of the current evidence base. Results: Available data are limited: five studies of which two were randomized, double-blind, placebo-controlled trials. One study indicated that memantine–ChEI combination is not significantly more effective than placebo–ChEI in mild to moderate AD, but data were published in abstract and poster form only. A second study indicated that the memantine–ChEI combination is significantly more effective than placebo–ChEI in moderate to severe AD. The calculated effect sizes of 0.36 on cognition and 0.12 on function, which were the primary outcomes, were small, indicating a clinically minimal effect on cognition and no effect on function. No data are available on whether combination treatment is more effective than memantine monotherapy. Conclusion: The available data do not justify the use of combination therapy. Future studies should include three arms (memantine–placebo, placebo–ChEI, and memantine–ChEI), be of an adequate size and duration, and use pragmatic measures. Clinicians should have full access to data from any future trials.

New drugs for type 2 diabetes mellitus:what is their place in therapy?

Oral therapy for type 2 diabetes mellitus, when used appropriately, can safely assist patients to achieve glycaemic targets in the short to medium term. However, the progressive nature of type 2 diabetes usually requires a combination of two or more oral agents in the longer term, often as a prelude to insulin therapy. Issues of safety and tolerability, notably weight gain, often limit the optimal application of anti-diabetic drugs such as sulforylureas and thiazolidinediones. Moreover, the impact of different drugs, even within a single class, on the risk of long-term vascular complications has come under scrutiny. For example, recent publication of evidence suggesting potential detrimental effects of rosiglitazone on myocardial events generated a heated debate and led to a reduction in use of this drug. In contrast, current evidence supports the view that pioglitazone has vasculoprotective properties. Both drugs are contraindicated in patients who are at risk of heart failure. An additional recently identified safety concern is an increased risk of fractures, especially in postmenopausal women. Several new drugs with glucose-lowering efficacy that may offer certain advantages have recently become available. These include (i) injectable glucagonlike peptide-1 (GLP-1) receptor agonists and oral dipeptidyl peptidase-4 (DPP-4) inhibitors; (ii) the amylin analogue pramlintide; and (iii) selective cannabinoid receptor-1 (CB1) antagonists. GLP-1 receptor agonists, such as exenatide, stimulate nutrient-induced insulin secretion and reduce inappropriate glucagon secretion while delaying gastric emptying and reducing appetite. These agents offer a low risk of hypoglycaemia combined with sustained weight loss. The DPP-4 inhibitors sitagliptin and vildagliptin are generally weight neutral, with less marked gastrointestinal adverse effects than the GLP-1 receptor agonists. Potential benefits of GLP-1 receptor stimulation on P cell neogenesis are under investigation. Pancreatitis has been reported in exenatide-treated patients. Pramlintide, an injected peptide used in combination with insulin, can reduce insulin dose and bodyweight. The CB1 receptor antagonist rimonabant promotes weight loss and has favourable effects on aspects of the metabolic syndrome, including the hyperglycaemia of type 2 diabetes. However, in 2007 the US FDA declined approval of rimonabant, requiring more data on adverse effects, notably depression. The future of dual peroxisome proliferator-activated receptor-alpha/gamma agonists, or glitazars, is presently uncertain following concerns about their safety. In conclusion, several new classes of drugs have recently become available in some countries that offer new options for treating type 2 diabetes. Beneficial or neutral effects on bodyweight are an attractive feature of the new drugs. However, the higher cost of these agents, coupled with an absence of long-term safety and clinical outcome data, need to be taken into consideration by clinicians and healthcare organizations.

Avandamet:Combined metformin-rosiglitazone treatment for insulin resistance in type 2 diabetes

Insulin resistance is a major endocrinopathy underlying the development of hyperglycaemia and cardiovascular disease in type 2 diabetes. Metformin (a biguanide) and rosiglitazone (a thiazolidinedione) counter insulin resistance, acting by different cellular mechanisms. The two agents can be used in combination to achieve additive glucose-lowering efficacy in the treatment of type 2 diabetes, without stimulating insulin secretion and without causing hypoglycaemia. Both agents also reduce a range of atherothrombotic factors and markers, indicating a lower cardiovascular risk. Early intervention with metformin is already known to reduce myocardial infarction and increase survival in overweight type 2 patients. Recently, a single-tablet combination of metformin and rosiglitazone, Avandamet, has become available. Avandamet is suitable for type 2-diabetic patients who are inadequately controlled by monotherapy with metformin or rosiglitazone. Patients already receiving separate tablets of metformin and rosiglitazone may switch to the single-tablet combination for convenience. Also, early introduction of the combination before maximal titration of one agent can reduce side effects. Use of Avandamet requires attention to the precautions for both metformin and rosiglitazone, especially renal, cardiac and hepatic competence. In summary, Avandamet is a single-tablet metformin-rosiglitazone combination that doubly targets insulin resistance as therapy for hyperglycaemia and vascular risk in type 2 diabetes. © 2004 Blackwell Publishing Ltd.

The Influence of Psychological Predictors and Cognitive Behavioral Stress Management Intervention on Antiretroviral Therapy (ART) Adherence Among HIV-Positive Female Haitian Alcohol Users

Purpose: Over half the HIV-infected persons in the Caribbean, the second most HIV-impacted region in the world, live in Haiti. Using secondary data from a parent study, this research assessed the effects of psychological and social factors on antiretroviral therapy (ART) adherence among Haitian, HIV-positive, female alcohol users. Theoretical Foundation and Research Questions: Using the Theory of Planned Behavior/Reasoned Action and the Information, Motivation, Behavior skills model as guiding theoretical frameworks, the study examined the effectiveness of an adapted cognitive behavioral stress management (CBSM-A) intervention in improving ART adherence. The effect of psychological factors (depression, anxiety, beliefs about medicine, and social support), social factors (stigma, relationship status, and educational attainment), and alcohol on adherence to ART was assessed. Methods: The sample consisted of 116 female ART patients who were randomly assigned to the CBSM-A intervention or the wait-list control group. Participants completed intervention sessions as well as pre- and post-test assessments. Analyses of variance, t-tests, and point biserial correlations were used to test hypotheses. Results: Surprisingly, ART adherence rates significantly decreased for both groups combined [F (1, 108) = 8.79, p = .004]; there was no significant difference between the intervention and control groups with regard to the magnitude of change between baseline and post assessment. On average, depression decreased significantly among participants in the CBSM-A group only [(t (62) = 5.54, p < .001)]. For both groups combined, alcohol use significantly decreased between baseline and post-assessment [(F (1, 78) = 34.70, p < .001)]; there was no significant difference between the intervention and control groups with regard to the magnitude of change between baseline and post-assessment. None of the variables were significantly correlated with ART adherence. Discussion: Adherence to ART did not improve in this sample, nor were any of the variables significantly associated with adherence. The findings suggest that additional supportive and psychological services may be needed in order to promote higher adherence to ART among HIV-positive females. More research may be needed on this sample; a focus on mental health issues, partner conflict, family and sexual history may allow for better targeting and more successful interventions.

Clinician perceptions of factors that enhance patient compliance in physical therapy

The purpose of this study was to determine physical therapists utilization of methods to increase compliance with home exercise programs, and to determine their perceptions of barriers patients have to completing exercise programs. The secondary purpose of this study was to describe the association, if any, between therapists' age, participation in exercise and/or lifestyle changes and the utilization of methods to increase exercise compliance. A sample of 73 physical therapists attending the American Physical Therapy Association Combined Sections Meeting were surveyed for this study. This study found that barriers listed by patients were similar to those found in the literature. This study also found that a significant association, p = .015, existed between therapists engaging in behavioral changes and use of lifestyle activities.

Discovery and Characterization of a Novel Fatty Acid Synthase Inhibitor with Antineoplastic Activity against Breast Cancer

During oncogenesis, cancer cells go through metabolic reprogramming to maintain their high growth rates and adapt to changes in the microenvironment and the lack of essential nutrients. Several types of cancer are dependent on de novo fatty acid synthesis to sustain their growth rates by providing precursors to construct membranes and produce vital signaling lipids. Fatty acid synthase (FASN) catalyze the terminal step of de novo fatty acid synthesis and it is highly expressed in many types of cancers where it’s up-regulation is correlated with cancer aggressiveness and low therapeutic outcome. Many FASN inhibitors were developed and showed potent anticancer activity however, only one inhibitor advanced to early stage clinical trials with some dose limiting toxicities. Using a modified fluorescence-linked enzyme chemoproteomic strategy (FLECS) screen, we identified HS-106, a thiophenopyrimiden FASN inhibitor that has anti-neoplastic activity against breast cancer in vitro and in vivo. HS-106 was able to inhibit both; purified human FASN activity and cellular fatty acid synthesis activity as evaluated by radioactive tracers incorporation into lipids experiments. In proliferation and apoptosis assays, HS-106 was able to block proliferation and induce apoptosis in several breast cancer cell lines. Several rescue experiment and global lipidome analysis were performed to probe the mechanism by which HS-106 induces apoptosis. HS-106 was found to induce several changes in lipids metabolism: (i) inhibit fatty acids synthesis. (ii) Inhibit fatty acids oxidation as indicated by the ability of inhibiting Malonyl CoA accumulation to block HS-106 induced apoptosis and the increase in the abundance of ceramides. (iii) Increase fatty acids uptake and neutral lipids formation as confirmed 14C Palmitate uptake assay and neutral lipids staining. (iv)Inhibit the formation of phospholipids by inhibiting de novo fatty acid synthesis and diverting exogenous fatty acids to neutral lipids. All of these events would lead to disruption in membranes structure and function. HS-106 was also tested in Lapatinib resistant cell lines and it was able to induce apoptosis and synergizes Lapatinib activity in these cell lines. This may be due the disruption of lipid rafts based on the observation that HS-106 reduces the expression of both HER2 and HER3. HS-106 was found to be well tolerated and bioavailable in mice with high elimination rate. HS-106 efficacy was tested in MMTV neu mouse model. Although did not significantly reduced tumor size (alone), HS-106 was able to double the median survival of the mice and showed potent antitumor activity when combined with Carboplatin. Similar results were obtained when same combinations and dosing schedule was used in C3Tag mouse model except for the inability of HS-106 affect mice survival.

From the above, HS-106 represent a novel FASN inhibitor that has anticancer activity both in vivo and in vitro. Being a chemically tractable molecule, the synthetic route to HS-106 is readily adaptable for the preparation of analogs that are similar in structure, suggesting that, the pharmacological properties of HS-106 can be improved.

Enhancement of a novel gene therapy approach for Sandhoff disease through complimentary drug therapy

GM2 gangliosidoses is a family of severe, neurodegenerative disorders resulting from a deficiency in the β-hexosaminidase A (Hex A) enzyme. This disorder is typically caused by a mutation to either the HEXA gene, causing Tay Sachs disease, or a mutation to the HEXB gene, causing Sandhoff disease. The HEXA and HEXB genes are required to produce the α and β subunits of the Hex A enzyme respectively. Using a Sandhoff disease (SD) mouse model (Hexb-/-) we tested the potential of a low dose of systemically delivered single stranded adeno-associated virus 9 (ssAAV9) expressing human HEXB and human HEXA cDNA under the control of a single promoter through the use of a bicistronic vector design with a P2A linker to correct the neurological phenotype. Neonatal mice were injected with either this ssAAV9-HexB-P2A-HexA vector (HexB-HexA) or a vehicle solution via the superficial temporal vein. HexB-HexA treatment alone conferred an increase in survival of 56% compared to vehicle-injected controls and biochemical analysis of the brain tissue and serum revealed an increase in HexA activity and a decrease in brain GM2 ganglioside buildup. Additionally, treatments with the non-steroidal anti-inflammatory drug indomethacin (Indo), the histone deactylase inhibitor ITF2357 (ITF) and the pharmacological chaperone pyrimethamine (Pyr) were tested. The anti-inflammatory treatments of Indo and ITF conferred an increase in survival of 12% and 8% respectively while causing no alteration in the HexA activity or GM2 ganglioside buildup. Pyr had no observable effect on disease progression. Lastly HexB-HexA treatment was tested in conjunction with Indo, ITF and Pyr individually. Additive increases in survival and behavioural testing results were observed with Indo and ITF treatments while no additional benefit to HexA activity or GM2 ganglioside levels in the brain tissue was observed. This indicates the two treatments slowed the progression of the disease through a different mechanism than the reduction of the GM2 ganglioside substrate. Pyr treatment was shown to have no effect when combined with HexB-HexA treatment. This study demonstrates the potential amelioration of SD with a novel AAV9 gene therapy approach as well as helped to identify the additive potential of anti-inflammatory treatments in gene therapy of GM2 gangliosidoses.

TP53 mutational status and cetuximab benefit in rectal cancer: 5-year results of the EXPERT-C trial.

In this updated analysis of the EXPERT-C trial we show that, in magnetic resonance imaging-defined, high-risk, locally advanced rectal cancer, adding cetuximab to a treatment strategy with neoadjuvant CAPOX followed by chemoradiotherapy, surgery, and adjuvant CAPOX is not associated with a statistically significant improvement in progression-free survival (PFS) and overall survival (OS) in both KRAS/BRAF wild-type and unselected patients. In a retrospective biomarker analysis, TP53 was not prognostic but emerged as an independent predictive biomarker for cetuximab benefit. After a median follow-up of 65.0 months, TP53 wild-type patients (n = 69) who received cetuximab had a statistically significant better PFS (89.3% vs 65.0% at 5 years; hazard ratio [HR] = 0.23; 95% confidence interval [CI] = 0.07 to 0.78; two-sided P = .02 by Cox regression) and OS (92.7% vs 67.5% at 5 years; HR = 0.16; 95% CI = 0.04 to 0.70; two-sided P = .02 by Cox regression) than TP53 wild-type patients who were treated in the control arm. An interaction between TP53 status and cetuximab effect was found (P <.05) and remained statistically significant after adjusting for statistically significant prognostic factors and KRAS.

HER2 in high-risk rectal cancer patients treated in EXPERT-C, a randomized phase II trial of neoadjuvant capecitabine and oxaliplatin (CAPOX) and chemoradiotherapy (CRT) with or without cetuximab.

BACKGROUND: HER2 is an established therapeutic target in breast and gastric cancers. The role of HER2 in rectal cancer is unclear, as conflicting data on the prevalence of HER2 expression in this disease have been reported. We evaluated the prevalence of HER2 and its impact on the outcome of high-risk rectal cancer patients treated with neoadjuvant CAPOX and CRT±cetuximab in the EXPERT-C trial. PATIENTS AND METHODS: Eligible patients with available tumour tissue for HER2 analysis were included. HER2 expression was determined by immunohistochemistry (IHC) in pre-treatment biopsies and/or surgical specimens (score 0-3+). Immunostaining was scored according to the consensus panel recommendations on HER2 scoring for gastric cancer. Tumours with equivocal IHC result (2+) were tested for HER2 amplification by D-ISH. Tumours with IHC 3+ or D-ISH ratio ≥2.0 were classified as HER2+. The impact of HER2 on primary and secondary end points of the study was analysed. RESULTS: Of 164 eligible study patients, 104 (63%) biopsy and 114 (69%) surgical specimens were available for analysis. Only 3 of 104 (2.9%) and 3 of 114 (2.6%) were HER2+, respectively. In 77 patients with paired specimens, concordance for HER2 status was found in 74 (96%). Overall, 141 patients were assessable for HER2 and 6 out of 141 (4.3%) had HER2 overexpression and/or amplification. The median follow-up was 58.6 months. HER2 was not associated with a difference in the outcome for any of the study end points, including in the subset of 90 KRAS/BRAF wild-type patients treated±cetuximab. CONCLUSIONS: Based on the low prevalence of expression as recorded in the EXPERT-C trial, HER2 does not appear to represent a useful therapeutic target in high-risk rectal cancer. However, the role of HER2 as a potential predictive biomarker of resistance to anti-EGFR-based treatments and a therapeutic target in anti-EGFR refractory metastatic colorectal cancer (CRC) warrants further investigation. TRIAL REGISTRATION: ISRCTN Register: 99828560.