Distinctive genetic and clinical features of CMT4J: a severe neuropathy caused by mutations in the PI(3,5)P₂ phosphatase FIG4

Charcot-Marie-Tooth disease is a genetically heterogeneous group of motor and sensory neuropathies associated with mutations in more than 30 genes. Charcot-Marie-Tooth disease type 4J (OMIM 611228) is a recessive, potentially severe form of the disease caused by mutations of the lipid phosphatase FIG4. We provide a more complete view of the features of this disorder by describing 11 previously unreported patients with Charcot-Marie-Tooth disease type 4J. Three patients were identified from a small cohort selected for screening because of their early onset disease and progressive proximal as well as distal weakness. Eight patients were identified by large-scale exon sequencing of an unselected group of 4000 patients with Charcot-Marie-Tooth disease. In addition, 34 new FIG4 variants were detected. Ten of the new CMT4J cases have the compound heterozygous genotype FIG4(I41T/null) described in the original four families, while one has the novel genotype FIG4(L17P/nul)(l). The population frequency of the I41T allele was found to be 0.001 by genotyping 5769 Northern European controls. Thirty four new variants of FIG4 were identified. The severity of Charcot-Marie-Tooth disease type 4J ranges from mild clinical signs to severe disability requiring the use of a wheelchair. Both mild and severe forms have been seen in patients with the same genotype. The results demonstrate that Charcot-Marie-Tooth disease type 4J is characterized by highly variable onset and severity, proximal as well as distal and asymmetric muscle weakness, electromyography demonstrating denervation in proximal and distal muscles, and frequent progression to severe amyotrophy. FIG4 mutations should be considered in Charcot-Marie-Tooth patients with these characteristics, especially if found in combination with sporadic or recessive inheritance, childhood onset and a phase of rapid progression.

Does apolipoprotein E genotype modify the clinical expression of ALS?

BACKGROUND

The presence of the apolipoprotein E (ApoE) 4 genotype is associated with an earlier age of onset for Alzheimer's disease (AD) and several other neurodegenerative disorders. The objective of this study was to investigate the effect of ApoE genotypes on the clinical course of amyotrophic lateral sclerosis (ALS).

METHODS

Eight hundred and fifty-two consecutive patients with sporadic ALS evaluated at a tertiary care center were investigated for the effect of ApoE genotype on age of onset, rate of motor disease progression, cognitive functioning, and survival in ALS.

RESULTS

The frequencies of individual ApoE genotypes did not differ between patients with ALS and ALS-free Caucasian populations. Patients with different ApoE genotypes did not differ in the age of onset for ALS (years) (ApoE2 = 57.8 ± 13.7, ApoE3 = 57.3 ± 13.7, ApoE4 = 57.7 ± 13.2; P = 0.97), the rate of disease progression (Appel ALS score/month) (ApoE2 = 2.91 ± 2.66, ApoE3 = 2.67 ± 2.66, ApoE4 = 2.61 ± 2.47; P = 0.89), cognitive status (% cognitively impaired) (ApoE2 = 31.7, ApoE3 = 26.8, ApoE4 = 34.3, P = 0.28), or survival in years (ApoE2 = 3.79 ± 3.70, ApoE3 = 3.17 ± 2.27, ApoE4 = 3.05 ± 1.75; P = 0.85).

CONCLUSIONS

Our results suggest that ApoE genotype does not modify clinical course of sporadic ALS, in stark contrast to the influence of ApoE genotype on the disease course of AD and other neurodegenerative disorders.

A decrease in body mass index is associated with faster progression of motor symptoms and shorter survival in ALS

Our objective was to test the hypothesis that changes in body mass index (BMI) are associated with changes in the clinical course of ALS. We examined the relationships between BMI at first clinical visit and changes in BMI up to a two-year follow-up, and multiple clinical variables related to ALS: age of onset, rate of progression of motor symptoms, and survival. Baseline BMI was classified according to the World Health Organization (WHO) criteria. Changes in BMI were classified as a loss of >1 unit, no change, or a gain of >1 unit. Our results showed that baseline BMI was not associated with age of onset, rate of progression or survival. In contrast, a loss of BMI >1 over two years was associated with significantly shorter survival and a faster rate of progression. In a multiple regression model, these results were independent of gender, site of onset, history of diabetes mellitus and apolipoprotein (ApoE) genotype. In summary, a change in BMI after ALS diagnosis was significantly associated with rate of progression and survival. This raises the possibility that early changes in BMI may identify patients likely to have a more malignant course of the disease. However, further research is needed to clarify the relationship between BMI and ALS.

Endogenous estrogen regulation of inflammatory arthritis and cytokine expression in male mice, predominantly via estrogen receptor alpha

OBJECTIVE

A number of experimental observations have associated elevated estrogen levels with amelioration of inflammation. The involvement of estrogen and estrogen receptor (ER) isotypes in the regulation of inflammation in males is not well understood. In this study, we used specific ERalpha and ERbeta agonists in male mice deficient in estrogen because of a deletion of aromatase (aromatase-knockout [ArKO] mice) to investigate ER isotype utilization in estrogen regulation of inflammation.

METHODS

Lipopolysaccharide (LPS)-induced cytokine expression and antigen-induced arthritis (AIA) were investigated in male ArKO and WT littermate mice, as well as in response to selective agonists of ERalpha (16alpha-LE2) and ERbeta (8beta-VE2). The therapeutic effect of selective ER agonists was also examined in mice with collagen-induced arthritis (CIA).

RESULTS

Estrogen deficiency in ArKO mice was associated with significant increases in LPS-induced serum interleukin-6 (IL-6), tumor necrosis factor, monocyte chemotactic protein 1, and interferon-gamma levels, which were significantly abrogated by administration of 16alpha-LE2, but not 8beta-VE2. In contrast, both 16alpha-LE2 and 8beta-VE2 significantly increased LPS-induced IL-10 levels. Estrogen deficiency was also associated with significant exacerbation of AIA and antigen-specific T cell proliferation, which was reversed by administration of either 16alpha-LE2 or 8beta-VE2. ArKO mice showed increased antigen-specific T cell proliferation in response to immunization with type II collagen (CII). Administration of 16alpha-LE2, but not 8beta-VE2, significantly reduced the severity of CIA, which was associated with inhibition of anti-CII-specific IgG.

CONCLUSION

These data indicate that endogenous estrogen plays an essential inhibitory role in inflammation in male mice and that ERalpha is the dominant receptor that mediates these effects.

ALS disease onset may occur later in patients with pre-morbid diabetes mellitus

BACKGROUND

Several metabolic derangements associated with diabetes mellitus type 2 (DM) have been associated with a better outcome in amyotrophic lateral sclerosis (ALS), including hyperlipidemia and obesity. Here, we tested the hypothesis that DM would have a positive effect on the motor and cognitive findings of ALS.

METHODS

We compared data from ALS patients with pre-morbid DM (ALS-DM; n = 175) versus without DM (ALS; n = 2196) with regard to the age of onset, rate of motor progression, survival, and neuropsychological test performance.

RESULTS

The age of onset was later for women, Caucasians and patients with bulbar-onset ALS. However, we also found that after adjusting for gender, ethnicity and site of onset, DM was associated with a 4-year later onset of ALS (ALS = 56.3, ALS-DM = 60.3, P < 0.05).

CONCLUSION

Diabetes mellitus type 2 may delay the onset of motor symptoms in ALS. These findings support other studies suggesting a relationship between the pathophysiology of ALS and metabolic derangements. Further investigations are needed to ascertain whether manipulating metabolic parameters would improve outcomes in ALS.

Metformin Inhibits Aromatase Expression in Primary Human Breast Adipose Stromal Cells

There is good epidemiological evidence that obesity is linked to an increased risk of cancers such as colon and breast. Given the obesity problem worldwide, it is now believed that tens of millions more women may contract breast cancer in their senior years than was previously thought. After menopause, when the ovaries have ceased to produce estrogens, it is the local expression of aromatase, the enzyme responsible for converting androgens to estrogens, within the breast adipose that is believed to be responsible for the increased proliferation of breast cancer cells.We have recently demonstrated that the LKB1/AMPK pathway is inhibitory of aromatase expression in primary human breast adipose stromal cells by inhibiting the nuclear entry of CRTC2, a CREB co-activator. Factors produced in obesity, such as leptin, and by tumors, such as PGE2, were shown to inhibit LKB1 expression and activity and cause the nuclear translocation of CRTC2, resulting in the increased expression of aromatase. Conversely, a factor produced in lean individuals, adiponectin, and the drug AICAR, known to activate AMPK, inhibited the PGE2-mediated expression of aromatase.There is growing evidence that the action of metformin, an oral anti-diabetic drug which has been used for many years, is mediated primarily by stimulation of AMPK, in association with interaction with its upstream kinase LKB1. In the present study, we aimed to examine the effect of metformin on aromatase expression and on the LKB1/AMPK pathway within the breast. Primary human breast adipose stromal cells obtained from breast reduction surgeries were treated with increasing amounts of 1,1-dimethylbiguanide hydrochloride (metformin) and aromatase transcript expression was quantified using real-time PCR. Interestingly, 24 hour treatment with metformin resulted in the dose-dependent inhibition of aromatase expression at concentrations of 10 and 50 uM. LKB1 activity was measured by examining the phosphorylation of AMPK by Western blotting and consistent with the proposed role of LKB1/AMPK in aromatase expression, metformin caused a significant increase in AMPK phosphorylation.Phase III aromatase inhibitors are proving highly successful as endocrine therapy for breast cancer in post-menopausal women, replacing Tamoxifen as frontline, second line and neoadjuvant therapy. However long-term contraindications such as bone loss, arthralgia, adverse cardiovascular effects and possibly cognitive defects may limit the use of these compounds in the prevention setting. Moreover, aromatase expression may be only one of several pathways whereby obesity influences breast cancer development. This study suggests that using a drug such as metformin which increases insulin sensitivity, causes weight loss and decreases the local biosynthesis of estrogens, may provide a multi-facetted approach at preventing and treating obesity-related postmenopausal estrogen-dependent breast cancer.Work supported by NHMRC project grant 494819 and the Terry Fox Foundation

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3132.

Epigenetic Control of Estrogen Synthesis in Human Preadipocytes and Breast Cancer Cells

Estrogen plays a significant role in the development and progression of breast cancer (BC). Cytochrome aromatase p450, encoded by the gene CYP19, is the key enzyme catalyzing the synthesis of estrogens from androgens. In post-menopausal women, adipose tissue becomes the major site for estrogen production and an increase in CYP19 expression in mammary adipose is strongly linked to the hormone-dependent progression of BC. Therefore, understanding CYP19 regulation in BC is critical for the development of therapeutic measures. Previous studies of CYP19 regulation in BC have mainly focussed on hormone-induced regulation of transcription via upstream tissue- and promoter-specific regulatory regions. While this is clearly important, it is increasingly evident that epigenetic regulation of expression, such as DNA methylation, is also a common factor in the progression of cancers. The aim of this study was to investigate whether CYP19 expression is under epigenetic regulation and to determine if such mechanisms contribute to the tissue- and promoter-specific expression of CYP19 observed in BC.CYP19 transcripts in cancer-free primary human breast adipose fibroblasts (BAFs) stimulated with cytokines and glucocorticoids (e.g. TNFα and dexamethasone) are derived from the distal promoter 1.4, whereas breast tumour-derived factors (e.g. prostaglandin E2) induce a regulatory switch to proximal promoters 1.3 and II. DNA from BAFs maintained under these two conditions was treated with sodium bisulfite allowing for methylation analysis of CpG dinucleotides. Methylation mapping revealed a stochastic heterogeneous level of methylation among 9 CpG sites (promoter 1.4) and 11 CpG sites (promoters 1.3 and II) in untreated BAFs.No correlation was observed between promoter methylation and promoter activation after response to stimuli. However, treatment of BAFs with 5-aza-2'-deoxycytidine, a DNA methylation inhibitor, increased total CYP19 mRNA expression up to 40-fold, primarily via promoter 1.4 thorugh up-regulation of trans-acting factors, suggesting CYP19 is under tonic inhibition by methylation in BAFs. Similar results were also obtained in four BC cell lines. Ongoing work has elucidated trans-acting factors of CYP19 epigenetically silenced in BAFs. These studies uncover a new layer of complexity in the regulation of aromatase expression in BC and may identify new targets for epigenetic therapy, including DNA methylation inhibitors. These findings will translate to BC by determining the methylation state of CYP19 in clinical BC specimens, and by correlation with clinicopathological parameters such as steroid receptor status, grade and stage.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1147.

Amantadine, oseltamivir and zanamivir for the prophylaxis of influenza (including a review of existing guidance no. 67): a systematic review and economic evaluation

OBJECTIVES

To evaluate the clinical effectiveness and incremental cost-effectiveness of amantadine, oseltamivir and zanamivir for seasonal and post-exposure prophylaxis of influenza.

DATA SOURCES

A MEDLINE search strategy was used and searches were carried out in July 2007.

REVIEW METHODS

An independent health economic model was developed based on a review of existing cost-effectiveness models and clinical advice.The model draws together a broad spectrum of evidence relating to the costs and consequences associated with influenza and its prevention. Where direct evidence concerning the effectiveness of prophylaxis within specific model subgroups was lacking, the model uses estimates from mixed subgroups or extrapolates from other mutually exclusive subgroups.

RESULTS

Twenty-six published references relating to 22 randomised controlled trials (RCTs) were included in the clinical effectiveness review, along with one unpublished report. Eight, six and nine RCTs were included for amantadine, oseltamivir and zanamivir respectively. The study quality was variable and gaps in the evidence base limited the assessment of the clinical effectiveness of the interventions. For seasonal prophylaxis, there was limited evidence for the efficacy of amantadine in preventing symptomatic, laboratory-confirmed influenza (SLCI) in healthy adults [relative risk (RR) 0.40, 95% confidence interval (CI) 0.08-2.03]. Oseltamivir was effective in preventing SLCI, particularly when used in at-risk elderly subjects (RR 0.08, 95% CI 0.01-0.63). The preventative efficacy of zanamivir was most notable in at-risk adults and adolescents (RR 0.17, 95% CI 0.07-0.44), and healthy and at-risk elderly subjects (RR 0.20, 95% CI 0.02-1.72). For post-exposure prophylaxis, data on the use of amantadine were again limited: in adolescents an RR of 0.10 (95% CI 0.03-0.34) was reported for the prevention of SLCI. Oseltamivir was effective in households of mixed composition (RR 0.19, 95% CI 0.08-0.45). The efficacy of zanamivir in post-exposure prophylaxis within households was also reported (RR 0.21, 95% CI 0.13-0.33). Interventions appeared to be well tolerated. Limited evidence was available for the effectiveness of the interventions in preventing complications and hospitalisation and in minimising length of illness and time to return to normal activities. No clinical effectiveness data were identified for health-related quality of life or mortality outcomes. With the exception of at-risk children, the incremental cost-utility of seasonal influenza prophylaxis is expected to be in the range 38,000-428,000 pounds per QALY gained (depending on subgroup). The cost-effectiveness ratios for oseltamivir and zanamivir as post-exposure prophylaxis are expected to be below 30,000 pounds per QALY gained in healthy children, at-risk children, healthy elderly and at-risk elderly individuals. Despite favourable clinical efficacy estimates, the incorporation of recent evidence of viral resistance to amantadine led to it being dominated in every economic comparison.

CONCLUSIONS

All three interventions showed some efficacy for seasonal and post-exposure prophylaxis. However, weaknesses and gaps in the clinical evidence base are directly relevant to the interpretation of the health economic model and rendered the use of advanced statistical analyses inappropriate. These data limitations should be borne in mind in interpreting the findings of the review.

Use of classical and novel biomarkers as prognostic risk factors for localised prostate cancer: a systematic review

OBJECTIVES

To provide an evidence-based perspective on the prognostic value of novel markers in localised prostate cancer and to identify the best prognostic model including the three classical markers and investigate whether models incorporating novel markers are better.

DATA SOURCES

Eight electronic bibliographic databases were searched during March-April 2007. The reference lists of relevant articles were checked and various health services research-related resources consulted via the internet. The search was restricted to publications from 1970 onwards in the English language.

METHODS

Selected studies were assessed, data extracted using a standard template, and quality assessed using an adaptation of published criteria. Because of the heterogeneity regarding populations, outcomes and study type, meta-analyses were not undertaken and the results are presented in tabulated format with a narrative synthesis of the results.

RESULTS

In total 30 papers met the inclusion criteria, of which 28 reported on prognostic novel markers and five on prognostic models. A total of 21 novel markers were identified from the 28 novel marker studies. There was considerable variability in the results reported, the quality of the studies was generally poor and there was a shortage of studies in some categories. The marker with the strongest evidence for its prognostic significance was prostate-specific antigen (PSA) velocity (or doubling time). There was a particularly strong association between PSA velocity and prostate cancer death in both clinical and pathological models. In the clinical model the hazard ratio for death from prostate cancer was 9.8 (95% CI 2.8-34.3, p < 0.001) in men with an annual PSA velocity of more than 2 ng/ml versus an annual PSA velocity of 2 ng/ml or less; similarly, the hazard ratio was 12.8 (95% CI 3.7-43.7, p < 0.001) in the pathological model. The quality of the prognostic model studies was adequate and overall better than the quality of the prognostic marker studies. Two issues were poorly dealt with in most or all of the prognostic model studies: inclusion of established markers and consideration of the possible biases from study attrition. Given the heterogeneity of the models, they cannot be considered comparable. Only two models did not include a novel marker, and one of these included several demographic and co-morbidity variables to predict all-cause mortality. Only two models reported a measure of model performance, the C-statistic, and for neither was it calculated in an external data set. It was not possible to assess whether the models that included novel markers performed better than those without.

CONCLUSIONS

This review highlighted the poor quality and heterogeneity of studies, which render much of the results inconclusive. It also pinpointed the small proportion of models reported in the literature that are based on patient cohorts with a mean or median follow-up of at least 5 years, thus making long-term predictions unreliable. PSA velocity, however, stood out in terms of the strength of the evidence supporting its prognostic value and the relatively high hazard ratios. There is great interest in PSA velocity as a monitoring tool for active surveillance but there is as yet no consensus on how it should be used and, in particular, what threshold should indicate the need for radical treatment.

An antibody combination that targets activated T cells extends graft survival in sensitized recipients

Memory T cells are the very essence of adaptive immunity with their rapid and efficient response to antigen rechallenge and long-term persistence. However, it is becoming increasingly evident that when primed with self or transplanted tissue, these cells play a key role in causing and perpetuating tissue damage. Furthermore, current treatments, which efficiently control the naive response, have limited effects on primed T cells. We have used a treatment based on a combination of antibodies specific for molecules expressed by activated T lymphocytes to selectively remove these cells. This approach, which we termed multi-hit therapy, leads to cumulative binding of antibodies to the target T cells and a striking prolongation of skin graft survival in presensitized recipients in a stringent skin transplant model. The findings are consistent with the depletion of graft-specific CD4+ and CD8+ T cells, although other modes of action, such as T-cell regulation and altered migration could play a role. In conclusion, our therapeutic strategy controls primed T cells which are a major driving force in the pathology of many autoimmune diseases and in transplant rejection.

Sensory ataxic neuropathy with ophthalmoparesis caused by POLG mutations

Mutations in POLG gene are responsible for a wide spectrum of clinical disorders with altered mitochondrial DNA (mtDNA) integrity, including mtDNA multiple deletions and depletion. Sensory ataxic neuropathy with ophthalmoparesis (SANDO) caused by mutations in POLG gene, fulfilling the clinical triad of sensory ataxic neuropathy, dysarthria and/or dysphagia and ophthalmoparesis, has described in a few reports. Here we described five cases of adult onset autosomal recessive sensory ataxic neuropathy with ophthalmoplegia. All patients had ataxia, neuropathy, myopathy, and progressive external ophthalmoplegia (PEO). The muscle pathology revealed ragged-red and cytochrome c oxidase (COX) negative fibers in three patients. However, deficiencies in the activities of mitochondrial respiratory chain enzyme complexes were not detected in any of the patients' muscle samples. Multiple deletions of mtDNA were detected in blood and muscle specimens but mtDNA depletion was not found. Due to these diagnostic difficulties, POLG-related syndromes are definitively diagnosed based on the presence of deleterious mutations in the POLG gene.

Taxanes for the adjuvant treatment of early breast cancer: systematic review and economic evaluation

OBJECTIVES

To estimate the clinical effectiveness and cost-effectiveness of docetaxel and paclitaxel compared with non-taxane, anthracycline-containing chemotherapy regimens, for the adjuvant treatment of women with early-stage breast cancer.

DATA SOURCES

Major electronic databases were searched between October 2005 and February 2006.

REVIEW METHODS

A systematic review of the literature on adjuvant taxane versus anthracycline non-taxane chemotherapy for women with early breast cancer was undertaken. A mathematical model was developed to synthesise the available data on costs, disease-free survival and health-related quality of life (HRQoL) of patients receiving taxane-containing chemotherapy versus non-taxane-containing chemotherapy.

RESULTS

Eight of the 11 selected trials (six docetaxel and five paclitaxel) reported a significant improvement in disease-free survival (DFS) or time to recurrence (TTR) for taxanes over comparator regimens. Docetaxel was associated with more adverse events than paclitaxel, most notably febrile neutropenia. Taxanes produced cardiotoxicity, although this was not reported to be greater than for anthracycline comparator arms in all trials. Treatment-related deaths were uncommon. Where reported, all chemotherapy regimens caused HRQoL to deteriorate during treatment. Following treatment, there were no clinically significant differences between taxane and comparator treatment groups. There were few data available comparing licensed regimens of taxanes with chemotherapy regimens commonly used in the UK. The three trials selected as the basis for the economic analysis were those that used the taxanes in accordance with current UK marketing authorisation and had also reported in full. The estimated incremental cost-effectiveness ratio for docetaxel compared to FAC6, based on the BCIRG 001 study, is 12,000 pounds (7000-39,000 pounds) and for paclitaxel compared with Adriamycin/cyclophosphamide, based on the NSABP B28 and CALGB 9344 studies, is 43,000 pounds (16,000 pounds-dominated) and 39,000 pounds (12,000 pounds-dominated), respectively. However, the comparators used in these trials restrict the generalisability of the results, as they do not conform to current standard care in the UK, typically FEC6 and E4-CMF4. An exploratory indirect comparison shows that the benefits of taxane containing regimens compared to regimens in current use in the UK is subject to large uncertainty due to the lack of direct trial comparisons between these interventions. Assumptions regarding the benefits in the taxane arm after the trial follow-up period and the annual rate of recurrence in this period have the most significant influence on the ICER.

CONCLUSIONS

There is a large degree of heterogeneity in the evidence base for the effectiveness of taxane- compared with non-taxane-containing regimens in terms of the interventions, comparators and populations. Eight of the 11 trials providing effectiveness data reported a significant improvement in DFS or TTR for taxanes over comparator regimens. The remaining three trials found no significant differences between the groups in DFS/TTR. The cost-effectiveness results suggest that the cost per quality-adjusted life-year for taxane- compared with non-taxane-containing chemotherapy varies between 12,000 pounds and 43,000 pounds, depending on the taxane under consideration and the specific trial used as the basis of the analysis. However, the comparators used in these trials do not conform to current standard care in the UK. More research is needed, comparing taxanes used in line with their current UK marketing authorisation and with anthracycline-containing regimens commonly used in the UK. The on-going TACT trial is expected to provide useful data. There are currently few data on the effectiveness of taxanes for the over-70s. Further research is required into the long-term outcomes of taxane therapy, such as whether there are any long-term adverse events that significantly impact on overall survival or quality of life and whether the increases in DFS will translate into increases in overall survival.

Adenocarcinoma in a retrorectal cystic hamartoma: a case report and literature review

Retrorectal cystic hamartomas are rare congenital lesions derived from the vestigial portion of the embryonic hindgut. These lesions present in a vague manner and so mimic the presentation of more common mass lesions in the pelvic region. They most frequently afflict middle-aged women, causing vague pelvic pains, discomfort with defaecation or sitting, and altered bowel function. Malignant transformation within these lesions is extremely rare. We describe a case of adenocarcinoma within a retrorectal cystic hamartoma, initially manifesting in a 54-year-old woman and recurring over a'5-year period. A computed tomography (CT) scan and pathology reports are included in the study, and findings at operations are discussed. We also include a comprehensive review of the literature.

Hormonal therapies for early breast cancer: systematic review and economic evaluation

OBJECTIVES

To establish the clinical and cost-effectiveness of aromatase inhibitors (AIs) anastrozole, letrozole and exemestane compared with tamoxifen in the adjuvant treatment of early oestrogen receptor-positive breast cancer in postmenopausal women.

DATA SOURCES

Major electronic databases and three trials registers were searched from May to June 2005. Three conference abstract databases were searched in December 2005. Industry submissions.

REVIEW METHODS

Studies evaluating the clinical effectiveness of AIs against 5 years' tamoxifen treatment were included and critically appraised. The review of the health economics of AIs in early breast cancer in comparison with standard therapies included a review of existing economic evaluations of the relevant therapies, a critique of each of the economic evaluations submitted to the National Institute for Health and Clinical Excellence (NICE) by pharmaceutical manufacturers and a detailed explanation of the methodologies and results of the authors' economic model. The three treatment strategies (primary adjuvant therapy, unplanned switch therapy and extended adjuvant therapy) were considered separately within the authors' economic analysis.

RESULTS

A meta-analysis of three trials found a significant difference in overall survival when an unplanned anastrozole switching strategy was compared with 5 years' tamoxifen. Significant improvements in overall survival are yet to be demonstrated in other strategies. Compared with 5 years' tamoxifen, disease-free survival (disease recurrence or death from any cause) was significantly improved in the primary adjuvant setting with anastrozole and letrozole, and with an exemestane switching strategy. Other trials did not report this outcome. Breast cancer recurrence (censoring death as an event) was significantly improved with primary adjuvant anastrozole and letrozole, anastrozole switching, extended adjuvant anastrozole or letrozole. The AIs and tamoxifen have different side-effect profiles, with tamoxifen responsible for small but statistically significant increases in endometrial cancer and, sometimes, thromboembolic events and stroke. AIs show a trend towards increases in osteoporosis, the statistical significance of which increases with follow-up time. The absence of tamoxifen treatment also increases the risk of hypercholesterolaemia and cardiac events in postmenopausal women. There was no significant difference in overall health-related quality of life between standard treatment and either primary adjuvant anastrozole and extended adjuvant letrozole strategies. The cost-effectiveness results for AIs compared with tamoxifen in the primary adjuvant setting, are estimated to be between 21,000 pounds and 32,000 pounds per quality-adjusted life-year (QALY) based on an analysis over 35 years. There is currently no trial evidence for exemestane in this setting. The cost-effectiveness results for anastrozole and exemestane, compared with tamoxifen in the unplanned switching setting, are estimated to be 23,200 pounds and 19,200 pounds per QALY, respectively, based on an analysis over 35 years. There is currently no trial evidence for letrozole in this setting. In the extended adjuvant setting, the cost per QALY for letrozole compared with placebo is estimated to be 9800 pounds, based on an analysis over 35 years. All these results are considered to be conservative. In the base case it is assumed that the benefits of AIs over tamoxifen or placebo seen during the therapy period are gradually lost during the following 10 years. An alternative scenario, the 'benefits maintained' scenario, is tested in sensitivity analysis. Here it is assumed that following the treatment period the annual rate of recurrence in both arms is the same. This reduces the cost-effectiveness ratio by over 50%, to around 10,000-12,000 pounds, 5000 pounds and 3000 pounds in the primary adjuvant, unplanned switching and extended adjuvant setting, respectively. The limited evidence to date of benefits after the therapy period suggests that the 'benefits maintained' scenario may be realistic. The results from the economic analyses within the industry submissions are generally lower than the results from the authors' model and are close to or below 12,000 pounds in all three settings. The authors' analyses generally produce a lower estimate of QALY gain for the aromatase inhibitors, due to the more conservative assumption regarding benefits, along with differences in the utility values used in the their analysis.

CONCLUSIONS

On the basis of the current data and within their licensed indications, AIs can be considered clinically effective compared with standard tamoxifen treatment. However, their long-term effects, in terms of both benefits and harms, remain unclear. Under the conservative assumption that benefits gained by AIs during the treatment period are gradually lost over the following 10 years, the cost per QALY for AIs compared with tamoxifen is estimated to be between 21,000 pounds and 32,000 pounds in the primary adjuvant setting and around 20,000 pounds in the unplanned switch setting. The cost per QALY for AIs compared with placebo in the extended adjuvant setting is estimated to be around 10,000 pounds. Under the less conservative assumption that rates of recurrence are the same in both arms after the therapy period is complete, the incremental cost-effectiveness ratios are typically at least 50% lower, suggesting that AIs are likely to be considered cost-effective in all three settings. Understanding of the long-term treatment effects on cost-effectiveness is, however, incomplete. Data on the impact of AIs on survival are awaited from the majority of the trials to confirm whether or not the benefits seen in disease-free survival and recurrence rates are translated into overall survival benefit in the medium to long-term.

Dietary zinc intake and sex differences in taste acuity in healthy young adults

BACKGROUND

Previous research suggests that adequate dietary zinc intake may be important in determining the sensory experience of food, appetite and consequently, dietary quality. The aim of this pilot study was to explore relationships between taste sensitivity and dietary zinc intake in healthy young adults (age 20-40 years: 24 male, mean age +/- SD = 27 +/- 4.86 years; 26 female, mean age +/- SD = 23 +/- 2.10).

METHOD

A signal detection method was used to assess taste acuity for the four basic tastes: sweet (glucose), sour (citric acid), salt (sodium chloride) and bitter (quinine). A 4-day food diary was used to determine dietary intakes of zinc (mg day(-1)) and salt.

RESULTS

Males reported a higher zinc intake than females (P=0.001). Higher dietary zinc intake was associated with better taste acuity for salt in females (P=0.017) but not in males. Acuity for bitter taste appeared to be related to zinc intake in males (P=0.007) but not females. Among those whose average daily zinc intake was below the RNI, males were less sensitive than females to sour (P=0.02) and bitter (P=0.014) taste.

CONCLUSION

These findings suggest that zinc is more important for taste acuity in males than females and indicate the importance of taking sex differences into account when studying taste acuity.

Mapping a new genetic locus for X linked retinitis pigmentosa to Xq28

We have defined a new genetic locus for an X linked form of retinitis pigmentosa (RP) on chromosome Xq28. We examined 15 members of a family in which RP appeared to be transmitted in an X linked manner. Ocular examinations were performed, and fundus photographs and electroretinograms were obtained for selected patients. Blood samples were obtained from all patients and an additional seven family members who were not given examinations. Visual acuity in four affected individuals ranged from 20/40 to 20/80+. Patients described the onset of night blindness and colour vision defects in the second decade of life, with the earliest at 13 years of age. Examined affected individuals had constricted visual fields and retinal findings compatible with RP. Based on full field electroretinography, cone function was more severely reduced than rod function. Female carriers had no ocular signs or symptoms and slightly reduced cone electroretinographic responses. Affected and non-affected family members were genotyped for 20 polymorphic markers on the X-chromosome spaced at 10 cM intervals. Genotyping data were analysed using GeneMapper software. Genotyping and linkage analyses identified significant linkage to markers DXS8061, DXS1073, and DXS1108 with two point LOD scores of 2.06, 2.17, and 2.20, respectively. Haplotype analysis revealed segregation of the disease phenotype with markers at Xq28.