Modelling incremental benefits on complications rates when targeting lower HbA1c levels in people with Type 2 diabetes and cardiovascular disease.

AIM: Glucose-lowering interventions in Type 2 diabetes mellitus have demonstrated reductions in microvascular complications and modest reductions in macrovascular complications. However, the degree to which targeting different HbA1c reductions might reduce risk is unclear. METHODS: Participant-level data for Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS) participants with established cardiovascular disease were used in a Type 2 diabetes-specific simulation model to quantify the likely impact of different HbA1c decrements on complication rates. Ten-year micro- and macrovascular rates were estimated with HbA1c levels fixed at 86, 75, 64, 53 and 42 mmol/mol (10%, 9%, 8%, 7% and 6%) while holding other risk factors constant at their baseline levels. Cumulative relative risk reductions for each outcome were derived for each HbA1c decrement. RESULTS: Of 5717 participants studied, 72.0% were men and 74.2% White European, with a mean (sd) age of 66.2 (7.9) years, systolic blood pressure 134 (16.9) mmHg, LDL-cholesterol 2.3 (0.9) mmol/l, HDL-cholesterol 1.13 (0.3) mmol/l and median Type 2 diabetes duration 9.6 (5.1-15.6) years. Ten-year cumulative relative risk reductions for modelled HbA1c values of 75, 64, 53 and 42 mmol/mol, relative to 86 mmol/mol, were 4.6%, 9.3%, 15.1% and 20.2% for myocardial infarction; 6.0%, 12.8%, 19.6% and 25.8% for stroke; 14.4%, 26.6%, 37.1% and 46.4% for diabetes-related ulcer; 21.5%, 39.0%, 52.3% and 63.1% for amputation; and 13.6%, 25.4%, 36.0% and 44.7 for single-eye blindness. CONCLUSIONS: These simulated complication rates might help inform the degree to which complications might be reduced by targeting particular HbA1c reductions in Type 2 diabetes.

Planktic foraminifera form their shells via metastable carbonate phases.

The calcium carbonate shells of planktic foraminifera provide our most valuable geochemical archive of ocean surface conditions and climate spanning the last 100 million years, and play an important role in the ocean carbon cycle. These shells are preserved in marine sediments as calcite, the stable polymorph of calcium carbonate. Here, we show that shells of living planktic foraminifers Orbulina universa and Neogloboquadrina dutertrei originally form from the unstable calcium carbonate polymorph vaterite, implying a non-classical crystallisation pathway involving metastable phases that transform ultimately to calcite. The current understanding of how planktic foraminifer shells record climate, and how they will fare in a future high-CO2 world is underpinned by analogy to the precipitation and dissolution of inorganic calcite. Our findings require a re-evaluation of this paradigm to consider the formation and transformation of metastable phases, which could exert an influence on the geochemistry and solubility of the biomineral calcite.

Architecture of crossed-lamellar bivalve shells: the southern giant clam (Tridacna derasa, Röding, 1798).

Tridacna derasa shells show a crossed lamellar microstructure consisting of three hierarchical lamellar structural orders. The mineral part is intimately intergrown with 0.9 wt% organics, namely polysaccharides, glycosylated and unglycosylated proteins and lipids, identified by Fourier transform infrared spectrometry. Transmission electron microscopy shows nanometre-sized grains with irregular grain boundaries and abundant voids. Twinning is observed across all spatial scales and results in a spread of the crystal orientation angles. Electron backscatter diffraction analysis shows a strong fibre texture with the [001] axes of aragonite aligned radially to the shell surface. The aragonitic [100] and [010] axes are oriented randomly around [001]. The random orientation of anisotropic crystallographic directions in this plane reduces anisotropy of the Young's modulus and adds to the optimization of mechanical properties of bivalve shells.

Incidence of bone metastases and survival after a diagnosis of bone metastases in breast cancer patients.

BACKGROUND: Bone is the most common metastatic site associated with breast cancer. Using a database of women with breast cancer treated at Guy's Hospital, London 1976-2006 and followed until end 2010, we determined incidence of and survival after bone metastases. METHODS: We calculated cumulative incidence of bone metastases considering death without prior bone metastases as a competing risk. Risk of bone metastases was modelled through Cox-regression. Survival after bone metastases diagnosis was calculated using Kaplan-Meier methodology. RESULTS: Of the 7064 women, 589 (22%) developed bone metastases during 8.4 years (mean). Incidence of bone metastases was significantly higher in younger women, tumour size >5 cm, higher tumour grade, lobular carcinoma and ≥ four positive nodes, but was not affected by hormone receptor status. Median survival after bone metastases diagnosis was 2.3 years in women with bone-only metastases compared with <1 year in women with visceral and bone metastases. There was a trend for decreased survival for patients who developed visceral metastases early, and proportionately fewer patients in this group. INTERPRETATION: Incidence of bone metastases has decreased but bone metastases remain a highly relevant clinical problem due to the large number of patients being diagnosed with breast cancer.

Age at diagnosis and distant metastasis in breast cancer--a surprising inverse relationship.

INTRODUCTION: Predictors for site of distant metastasis and impact on survival in breast cancer are incompletely understood. METHODS: Clinico-pathological risk factors for site of distant metastasis and survival were analysed in patients with invasive breast cancer treated between 1986 and 2006. RESULTS: Of 3553 patients, with median follow-up 6.32years, 825 (23%) developed distant metastasis. The site of metastasis was bone in 196/825 (24%), viscera in 540/825 (65%) and unknown in 89 (11%). Larger primary invasive tumour size, higher tumour grade and axillary nodal positivity increased risk of metastasis to all sites. Lobular carcinoma was more likely to first metastasise to bone compared to invasive ductal carcinoma (NST). Oestrogen receptor (ER) negative, progesterone receptor (PgR) negative and/or Human epidermal growth factor (HER2) positive tumours were more likely to metastasise to viscera. A striking relationship between increasing age at diagnosis and a reduction in risk of distant metastasis to bone and viscera was observed. Median time to death from onset of metastatic disease was 1.52 (Interquartile range (IQR) 0.7-2.9)years for patients with bone metastasis and 0.7 (IQR 0.2-1.5)years for visceral metastasis. On multivariate analysis, despite the decrease in risk of distant metastasis with increasing age, there was an elevated hazard for death in patients >50years at diagnosis of metastasis if they developed bone metastasis, with a similar trend observed in the >70years age group if they developed visceral metastasis. CONCLUSION: These findings indicate that there are biological mechanisms underlying the impact of age on the development of distant metastasis and subsequent death. This may have important implications in the treatment of breast cancer.

When is a completion axillary lymph node dissection necessary in the presence of a positive sentinel lymph node?

BACKGROUND: The management of the axilla in the presence of positive sentinel lymph node (SLN) remains controversial. Many centres forgo completion axillary lymph node dissection (cALND) in the presence of micrometastatic disease. The American College of Surgeons Oncology Group (ACOSOG) Z0011 trialists argue for extending this to macrometastasis. The aim of this study was to correlate tumour burden in SLNs with that in the residual lymph node basin to determine the likelihood of residual disease in patients with micro- and macrometastasis in the SLN. METHODS: Patients who underwent cALND following a positive SLN were analysed for histopathological features of the primary tumour and burden of axillary disease. RESULTS: Of 155 patients, 115 (74%) had macrometastases and 40 (26%) micrometastases in the SLNs. Residual axillary disease was detected in 55/155 (35%) patients with macrometastases and 4/40 (10%) with micrometastases. Generally, with increasing size of metastasis in the SLN there was an increasing risk of further disease in residual lymph nodes. Logistic regression analysis showed increased odds ratios for further disease for all groups when compared with the <2mm (micrometastasis) SLN group. CONCLUSION: Patients may be advised to forgo cALND where the SLN contains isolated tumour cells or micrometastasis. Recommendations for proceeding to cALND can be based on the size of metastasis in the SLN, which relates to the risk of further disease in the residual axillary lymph nodes and subsequent regional recurrence.

Patterns of metastatic spread in early breast cancer.

AIMS: The aim of this study was to prospectively investigate metastatic pathways of spread to lymph node versus bone marrow and identify biological characteristics that determine these patterns in early invasive breast cancer. PATIENTS AND METHODS: In all, 177 patients with early invasive breast cancer underwent surgical extirpation of the primary tumour with sentinel lymph node biopsy (SLNB). Bone marrow (BM) aspiration was performed to screen for cytokeratin-positive cells by immunocytochemistry. Lymphatic spread was assessed by histopathological examination of lymph nodes (LN). A representative subset of 87 tumours was analysed by tissue microarray (TMA) to evaluate expression of markers that potentially influence haematogenous vs. lymphatic spread. Patients were followed up for a median of 54.7 months. RESULTS: Of the 177 patients, 114 (64%) were BM-/LN-, 38 (22%) BM-/LN+, 19 (11%) BM+/LN- and 6 (3%) BM+/LN+. Multivariate analysis of histopathological characteristics revealed that increasing tumour size was significantly associated with both LN positivity (p = 0.003) and BM positivity (p = 0.01), the presence of lymphovascular invasion significantly correlated with LN+ (p = 0.01), whereas lower histological grade was significantly associated with BM+ (p = 0.03). LN+ and BM+ were non-significantly negatively related to each other. Univariate analysis of the TMA data showed differential expression patterns for several factors; significant differences between effects on the two metastatic pathways (lymphatic vs. haematogenous) were found for expression of CD54 (p = 0.03), osteopontin (p = 0.04), bone sialoprotein (p = 0.04) and CXCR4 (p = 0.009). High expression of CD54, osteopontin and bone sialoprotein (BSP) was positively associated with BM + but was either not associated, or negatively associated, with LN+. High CXCR4 expression was positively associated with LN+ and negatively with BM+. High VEGF-C expression was associated with both LN+ and BM+, although this did not attain statistical significance. Due to the small number of clinical events during clinical follow-up, no associations were identified between metastatic spread patterns, recurrence and/or death. CONCLUSION: These findings suggest that distinct lymphatic and haematogenous metastatic pathways exist in early breast cancer and that these pathways are governed by specific biological markers.

Serum cotinine and prognosis in breast cancer.

Various studies have suggested that women who smoke have a worse prognosis if they develop breast cancer. Cotinine levels have been measured in sera from 511 patients with stage I and II breast cancer diagnosed between 1975 and 1980, all of whom had complete follow-up. Although the known prognostic factors, axillary nodal status, tumour size and grade were found to be significant, there was no relationship between serum cotinine and metastasis-free survival. A point estimate of serum cotinine was not found to be a determinant of survival in women with early breast cancer.

Factors influencing loco-regional relapse in older breast cancer patients treated with tumour resection and tamoxifen.

BACKGROUND: In breast cancer patients (≥70 years), tumour resection plus tamoxifen (T + T) has a higher loco-regional relapse (LR) rate than mastectomy. This study examines factors influencing local recurrence in these cases. METHODS: Clinical records of 71 patients aged ≥70 years, randomised to the T + T arm of 2 randomised trials were reviewed. Cox Proportional Hazards model was used to determine the most significant variables. RESULTS: After 15-years follow-up, LR relapse occurred in 29/71, of whom 5 had synchronous metastatic disease. Most tumours recurred in the index quadrant. Subsequently 21/24 patients with loco-regional recurrence only had salvage mastectomy. Three variables significantly predicted LR: lympho-vascular invasion (LVI) (HR [95% CI]: 11.18 [4.47, 27.95], p < 0.01), ER negative status (HR [95% CI]: 0.27 [0.10, 0.72] p = 0.01), and tumour necrosis (HR [95% CI]: 2.65 [1.10, 6.37], p = 0.03). Final margin status was not associated with LR. CONCLUSIONS: Tumour resection + Tamoxifen in older patients results in long-term local control in the majority with most loco-regional failures being salvageable. Risk factors for LR are lympho-vascular invasion, ER status and tumour necrosis. Negative tumour excision margins did not significantly change local outcome in the absence of radiotherapy. In these older patients LVI significantly reduced survival time.

What can be done about hot flushes after treatment for breast cancer?

Breast cancer survivors frequently experience severe hot flushes as a result of their treatment. This can adversely affect their quality of life, compliance with treatment and overall survival. To relieve vasomotor symptoms, a variety of drugs have been used including clonidine, gabapentin, selective serotonin reuptake inhibitors and selective norepinephrine reuptake inhibitors. Stellate ganglion block (SGB) has recently emerged as a new technique against hot flushes and preliminary studies report encouraging efficacy with minimal complications. Other approaches include various alternative treatments and, in a few cases, hormone replacement therapy (HRT). All randomized, controlled studies of drugs, hormone treatments and alternative therapies for vasomotor symptoms have been reviewed and efficacy and safety noted. Side-effects of current medical treatments frequently outweigh the benefits--leading many patients to discontinue the medications. Statistically significant differences between placebo and test agent may not translate into a meaningful subjective benefit. Desvenlafaxine looks promising as does SGB, despite its invasive nature. The favorable safety profile of SGB is confirmed through the long experience of SGB performed for other medical purposes. The majority of non-HRT treatments for hot flushes are little better than placebo but early results from randomized trials of desvenlafaxine and pilot studies of SGB suggest that it is worthwhile to test their efficacy specifically in breast cancer survivors.

Tetanus antibody levels among adolescent girls in developing countries.

Neonatal and maternal tetanus infections remain an important cause of death in many countries. Few studies have reported tetanus toxoid antibody levels of adolescent girls. As part of the Expanded Programme on Immunization most girls receive up to 3 injections in early childhood, and many subsequently do not receive booster vaccinations until pregnant. We determined (by ELISA) tetanus antibody seropositivity in adolescent girls from Malawi (in 1996), Nigeria (in 1993) and Pakistan (in 1996), and response to tetanus vaccination in adolescent girls from Pakistan. Geometric mean titres (GMT, IU/mL) were 0.94 in 117 Malawian, 0.32 in 154 Nigerian and 1.08 in 162 Pakistani girls. In Nigeria, 54.7% of adolescents were seronegative, of whom 26.8% had a history of unsafe abortion. In Malawi and Pakistan all girls were seropositive and in Pakistan, following a booster vaccination, titres increased 3-fold, with a lower response in older girls. The results indicated that adequate childhood immunization is likely to provide protective levels through adolescence. Booster vaccination in late childhood/early adolescence should protect the majority of women throughout their reproductive lives. This practice would reduce the risks of girls exposed to infection through unsafe abortions, and may be the best option for countries seeking to improve their vaccination schedule, especially where tetanus vaccine coverage in pregnant women is unacceptably low.

A community based study of vitamin A and vitamin E status of adolescent girls living in the Shire Valley, Southern Malawi.

OBJECTIVE: To assess vitamin A and E status and anaemia in non-pregnant Malawian adolescent girls. DESIGN: A cross-sectional study in rural village communities in the Shire Valley, Southern Malawi. SUBJECTS: Adolescent girls, n = 118, aged between 10 and 19 y, 112 of whom were unmarried. METHODS: Socio-demographic information was collected by questionnaire, heights and weights were measured. Vitamin A was assessed by the Modified Relative Dose Response (MRDR) test, in addition to serum retinol values. Blood samples were collected 4-5 h after administration of 3,4-didehydroretinyl acetate. Retinol and alpha-tocopherol levels were measured by HPLC. Serum retinol results for non-pregnant girls were compared with values for 43 adolescent pregnant girls which were available from a previous study. RESULTS: 26.6% of non-pregnant girls had serum retinol values < 0.70 micromol/L; 40.2% had an MRDR ratio > 0.060. In 59.3%, serum tocopherol levels were < 11.5 micromol/L and the tocopherol/cholesterol ratio was < 2.2 in 23.9%. 11.3% had a haemoglobin > or = 12 g/dl. Vitamin A levels were significantly related to age, and younger girls were more likely to be deficient. Significant correlations were found between serum retinol, MRDR values and serum tocopherol. Girls with a low body mass index for age had tocopherol cholesterol ratios < 2.2. Low serum retinol values occurred significantly more often in stunted girls (P=0.01). Serum retinol values of adolescent pregnant girls were significantly lower than those of non-pregnant adolescents (P=0.002). CONCLUSIONS: Vitamin A and E deficiency and anaemia were common in adolescent non-pregnant girls, and thought to partly result from increased growth requirements. Girls who become pregnant at an early age are at risk of depletion of their nutritional reserves. Measures to reduce nutritional deficiencies before the first pregnancy are needed.