Genetic variants of CYP3A5, CYP2D6, SULT1A1, UGT2B15 and tamoxifen response in postmenopausal patients with breast cancer

INTRODUCTION: Tamoxifen therapy reduces the risk of recurrence and prolongs the survival of oestrogen-receptor-positive patients with breast cancer. Even if most patients benefit from tamoxifen, many breast tumours either fail to respond or become resistant. Because tamoxifen is extensively metabolised by polymorphic enzymes, one proposed mechanism underlying the resistance is altered metabolism. In the present study we investigated the prognostic and/or predictive value of functional polymorphisms in cytochrome P450 3A5 CYP3A5 (*3), CYP2D6 (*4), sulphotransferase 1A1 (SULT1A1; *2) and UDP-glucuronosyltransferase 2B15 (UGT2B15; *2) in tamoxifen-treated patients with breast cancer. METHODS: In all, 677 tamoxifen-treated postmenopausal patients with breast cancer, of whom 238 were randomised to either 2 or 5 years of tamoxifen, were genotyped by using PCR with restriction fragment length polymorphism or PCR with denaturing high-performance liquid chromatography. RESULTS: The prognostic evaluation performed in the total population revealed a significantly better disease-free survival in patients homozygous for CYP2D6*4. For CYP3A5, SULT1A1 and UGT2B15 no prognostic significance was observed. In the randomised group we found that for CYP3A5, homozygous carriers of the *3 allele tended to have an increased risk of recurrence when treated for 2 years with tamoxifen, although this was not statistically significant (hazard ratio (HR) = 2.84, 95% confidence interval (CI) = 0.68 to 11.99, P = 0.15). In the group randomised to 5 years' tamoxifen the survival pattern shifted towards a significantly improved recurrence-free survival (RFS) among CYP3A5*3-homozygous patients (HR = 0.20, 95% CI = 0.07 to 0.55, P = 0.002). No reliable differences could be seen between treatment duration and the genotypes of CYP2D6, SULT1A1 or UGT2B15. The significantly improved RFS with prolonged tamoxifen treatment in CYP3A5*3 homozygotes was also seen in a multivariate Cox model (HR = 0.13, CI = 0.02 to 0.86, P = 0.03), whereas no differences could be seen for CYP2D6, SULT1A1 and UGT2B15. CONCLUSION: The metabolism of tamoxifen is complex and the mechanisms responsible for the resistance are unlikely to be explained by a single polymorphism; instead it is a combination of several mechanisms. However, the present data suggest that genetic variation in CYP3A5 may predict response to tamoxifen therapy

Medical Management of Infants With Supraventricular Tachycardia: Results From a Registry and Review of the Literature

Background: Several medication choices are available for acute and prophylactic treatment of refractory supraventricular tachycardia (SVT) in infants. There are almost no controlled trials, and medication choices are not necessarily evidence based. Our objective was to report the effectiveness of management strategies for infant SVT. Methods: A registry of infants admitted to hospital with re-entrant SVT and no haemodynamically significant heart disease were prospectively followed at 11 international tertiary care centres. In addition, a systematic review of studies on infant re-entrant SVT in MEDLINE and EMBASE was conducted. Data on demographics, symptoms, acute and maintenance treatments, and outcomes were collected. Results: A total of 2534 infants were included: n = 108 from the registry (median age, 9 days [0-324 days], 70.8% male) and n = 2426 from the literature review (median age, 14 days; 62.3% male). Propranolol was the most prevalent acute (61.4%) and maintenance treatment (53.8%) in the Registry, whereas digoxin was used sparingly (4.0% and 3.8%, respectively). Propranolol and digoxin were used frequently in the literature acutely (31% and 33.2%) and for maintenance (17.8% and 10.1%) (P < 0.001). No differences in acute or prophylactic effectiveness between medications were observed. Recurrence was higher in the Registry (25.0%) vs literature (13.4%) (P < 0.001), and 22 (0.9%) deaths were reported in the literature vs none in the Registry. Conclusion: This was the largest cohort of infants with SVT analysed to date. Digoxin monotherapy use was rare amongst contemporary paediatric cardiologists. There was limited evidence to support one medication over another. Overall, recurrence and mortality rates on antiarrhythmic treatment were low. Résumé: Contexte: De nombreux choix de médicaments existent pour le traitement aigu et prophylactique de la tachycardie supraventriculaire (TSV) réfractaire chez les nourrissons. Or, il n’y a presque pas d’essais contrôlés à ce sujet, et les choix de médicaments ne sont pas nécessairement fondés sur des données probantes. Notre objectif était de faire état de l’efficacité des stratégies de prise en charge de la TSV chez les nourrissons. Méthodologie: Un registre des nourrissons admis à l’hôpital pour une TSV par réentrée, sans cardiopathie d’importance hémodynamique, a été tenu de façon prospective dans 11 centres de soins tertiaires à l’échelle mondiale. De plus, une revue systématique des études sur la TSV par réentrée chez le nourrisson a été effectuée dans MEDLINE et EMBASE. Des données sur les caractéristiques démographiques, les symptômes, les traitements aigus et d’entretien, et les résultats ont été recueillis. Résultats: Un total de 2 534 nourrissons ont été inclus : n = 108 du registre (âge médian de 9 jours [0-324 jours], 70,8 % de sexe masculin) et n = 2 426 de la revue de la littérature (âge médian de 14 jours; 62,3 % de sexe masculin). Le propranolol était le traitement de soins aigus (61,4 %) et d’entretien (53,8 %) le plus fréquent dans le registre, alors que la digoxine a été utilisée occasionnellement (respectivement dans 4,0 % et 3,8 % des cas). Dans la littérature, le propranolol et la digoxine étaient fréquemment utilisés en soins aigus (31 % et 33,2 %) et en traitement d’entretien (17,8 % et 10,1 %) (p < 0,001). Aucune différence n’a été observée entre les médicaments au chapitre de l’efficacité du traitement de soins aigus ou du traitement prophylactique. Le taux de récurrence était plus élevé dans le registre (25,0 %) que dans la littérature (13,4 %) (p < 0,001), et 22 (0,9 %) décès ont été signalés dans la littérature, mais aucun dans le registre. Conclusion: Il s’agit de la plus grande cohorte de nourrissons atteints de TSV analysée à ce jour. De nos jours, les cardiologues pédiatriques prescrivent rarement la digoxine en monothérapie. Peu de données probantes favorisent l’utilisation d’un médicament par rapport à l’autre. Dans l’ensemble, les taux de récurrence et de mortalité sous traitement antiarythmique étaient faibles

The Reproductive Ecology of Industrial Societies, Part I : Why Measuring Fertility Matters.

Is fertility relevant to evolutionary analyses conducted in modern industrial societies? This question has been the subject of a highly contentious debate, beginning in the late 1980s and continuing to this day. Researchers in both evolutionary and social sciences have argued that the measurement of fitness-related traits (e.g., fertility) offers little insight into evolutionary processes, on the grounds that modern industrial environments differ so greatly from those of our ancestral past that our behavior can no longer be expected to be adaptive. In contrast, we argue that fertility measurements in industrial society are essential for a complete evolutionary analysis: in particular, such data can provide evidence for any putative adaptive mismatch between ancestral environments and those of the present day, and they can provide insight into the selection pressures currently operating on contemporary populations. Having made this positive case, we then go on to discuss some challenges of fertility-related analyses among industrialized populations, particularly those that involve large-scale databases. These include "researcher degrees of freedom" (i.e., the choices made about which variables to analyze and how) and the different biases that may exist in such data. Despite these concerns, large datasets from multiple populations represent an excellent opportunity to test evolutionary hypotheses in great detail, enriching the evolutionary understanding of human behavior

Intensity modulated radiotherapy for sinonasal malignancies with a focus on optic pathway preservation

<p>Abstract</p> <p>Purpose</p> <p>To assess if intensity-modulated radiotherapy (IMRT) can possibly lead to improved local control and lower incidence of vision impairment/blindness in comparison to non-IMRT techniques when treating sinonasal malignancies; what is the most optimal dose constraints for the optic pathway; and the impact of different IMRT strategies on optic pathway sparing in this setting.</p> <p>Methods and materials</p> <p>A literature search in the PubMed databases was conducted in July, 2012.</p> <p>Results</p> <p>Clinical studies on IMRT and 2D/3D (2 dimensional/3 dimensional) RT for sinonasal malignancies suggest improved local control and lower incidence of severe vision impairment with IMRT in comparison to non-IMRT techniques. As observed in the non-IMRT studies, blindness due to disease progression may occur despite a lack of severe toxicity possibly due to the difficulty of controlling locally very advanced disease with a dose ≤ 70 Gy. Concurrent chemotherapy’s influence on the the risk of severe optic toxicity after radiotherapy is unclear. A maximum dose of ≤ 54 Gy with conventional fractionation to the optic pathway may decrease the risk of blindness. Increased magnitude of intensity modulation through increasing the number of segments, beams, and using a combination of coplanar and non-coplanar arrangements may help increase dose conformality and optic pathway sparing when IMRT is used.</p> <p>Conclusion</p> <p>IMRT optimized with appropriate strategies may be the treatment of choice for the most optimal local control and optic pathway sparing when treating sinonasal malignancy.</p