Multi-ancestry genome-wide analysis identifies shared genetic effects and common genetic variants for self-reported sleep duration

Both short (≤6 h per night) and long sleep duration (≥9 h per night) are associated with increased risk of chronic diseases. Despite evidence linking habitual sleep duration and risk of disease, the genetic determinants of sleep duration in the general population are poorly understood, especially outside of European (EUR) populations. Here, we report that a polygenic score of 78 European ancestry sleep duration single-nucleotide polymorphisms (SNPs) is associated with sleep duration in an African (n = 7288; P = 0.003), an East Asian (n = 13 618; P = 6 × 10-4) and a South Asian (n = 7485; P = 0.025) genetic ancestry cohort, but not in a Hispanic/Latino cohort (n = 8726; P = 0.71). Furthermore, in a pan-ancestry (N = 483 235) meta-analysis of genome-wide association studies (GWAS) for habitual sleep duration, 73 loci are associated with genome-wide statistical significance. Follow-up of five loci (near HACD2, COG5, PRR12, SH3RF1 and KCNQ5) identified expression-quantitative trait loci for PRR12 and COG5 in brain tissues and pleiotropic associations with cardiovascular and neuropsychiatric traits. Overall, our results suggest that the genetic basis of sleep duration is at least partially shared across diverse ancestry groups.

Switching mechanism from AR to EGFR signaling via 3-O-sulfated heparan sulfate in castration-resistant prostate cancer

Androgen deprivation therapy is given to suppress prostate cancer growth; however, some cells continue to grow hormone-independently as castration-resistant prostate cancer (CRPC). Sulfated glycosaminoglycans promote ligand binding to receptors as co-receptors, but their role in CRPC remains unknown. Using the human prostate cancer cell line C4-2, which can proliferate in hormone-dependent and hormone-independent conditions, we found that epidermal growth factor (EGF)-activated EGFR-ERK1/2 signaling via 3-O-sulfated heparan sulfate (HS) produced by HS 3-O-sulfotransferase 1 (HS3ST1) is activated in C4-2 cells under hormone depletion. Knockdown of HS3ST1 in C4-2 cells suppressed hormone-independent growth, and inhibited both EGF binding to the cell surface and activation of EGFR-ERK1/2 signaling. Gefitinib, an EGFR inhibitor, significantly suppressed C4-2 cell proliferation and growth of a xenografted C4-2 tumor in castrated mouse. Collectively, our study has revealed a mechanism by which cancer cells switch to hormone-independent growth and identified the key regulator as 3-O-sulfated HS.

Machine-learning predicts time-series prognosis factors in metastatic prostate cancer patients treated with androgen deprivation therapy

Machine learning technology is expected to support diagnosis and prognosis prediction in medicine. We used machine learning to construct a new prognostic prediction model for prostate cancer patients based on longitudinal data obtained from age at diagnosis, peripheral blood and urine tests of 340 prostate cancer patients. Random survival forest (RSF) and survival tree were used for machine learning. In the time-series prognostic prediction model for metastatic prostate cancer patients, the RSF model showed better prediction accuracy than the conventional Cox proportional hazards model for almost all time periods of progression-free survival (PFS), overall survival (OS) and cancer-specific survival (CSS). Based on the RSF model, we created a clinically applicable prognostic prediction model using survival trees for OS and CSS by combining the values of lactate dehydrogenase (LDH) before starting treatment and alkaline phosphatase (ALP) at 120 days after treatment. Machine learning provides useful information for predicting the prognosis of metastatic prostate cancer prior to treatment intervention by considering the nonlinear and combined impacts of multiple features. The addition of data after the start of treatment would allow for more precise prognostic risk assessment of patients and would be beneficial for subsequent treatment selection.

The new preparation method for paraffin-embedded samples applying scanning electron microscopy revealed characteristic features in asthma-induced mice

In bronchial asthma patients, mucous cell metaplasia (MCM) and fibrosis occur in the bronchial epithelium and interstitium, respectively. The mucus and collagen fibers are identified by Periodic acid-Schiff stain (PAS) or Sirius red stain on optical microscopy. On a scanning electron microscope (SEM) observation, formalin-fixed-paraffin-embedded specimens have high insulation, thereby attenuating the scattered electron signals leading to insufficient contrast. Moreover, there were no staining methods for SEM observation, which characterizes the changes in epithelium and interstitium by enhancing the scattered electrons. In this study, we established a method of coating osmium thin film on pathological tissue specimens using plasma chemical vapor deposition technology. This method ensured the intensity of scattered electron signals and enabled SEM observation. Furthermore, we found that morphological changes in MCM and interstitial fibrosis could be characterized by Grocott stain, which we optimized to evaluate pathological remodeling in bronchial asthma. Using these techniques, we compared asthma-induced mice with Amphiregulin (Areg) knockout mice, and found that Areg induce MCM, but the production of Grocott-stain-positive substrate in the interstitium is Areg-independent. The method developed in this study provides an understanding of the pathological spatial information linked to the ultrastructural changes in cells and interstitium due to disease-related signaling abnormalities.

Functional analysis of LAT3 in prostate cancer: Its downstream target and relationship with androgen receptor

L‐type amino acid transporter 3 (LAT3, SLC43A1) is abundantly expressed in prostate cancer (PC) and is thought to play an essential role in PC progression through the cellular uptake of essential amino acids. Here, we analyzed the expression, function, and downstream target of LAT3 in PC. LAT3 was highly expressed in PC cells expressing androgen receptor (AR), and its expression was increased by dihydrotestosterone treatment and decreased by bicalutamide treatment. In chromatin immunoprecipitation sequencing of AR, binding of AR to the SLC43A1 region was increased by dihydrotestosterone stimulation. Knockdown of LAT3 inhibited cell proliferation, migration, and invasion, and the phosphorylation of p70S6K and 4EBP‐1. Separase (ESPL1) was identified as a downstream target of LAT3 by RNA sequencing analysis. In addition, immunostaining of prostatectomy specimens was performed. In the multivariate analysis, high expression of LAT3 was an independent prognostic factor for recurrence‐free survival (hazard ratio: 3.24; P = .0018). High LAT3 expression was correlated with the pathological T stage and a high International Society of Urological Pathology grade. In summary, our results suggest that LAT3 plays an important role in the progression of PC.

Impact of Lymphovascular Invasion on Prognosis in the Patients with Bladder Cancer-Comparison of Transurethral Resection and Radical Cystectomy

(1) Background: This study aimed to evaluate the associations of lymphovascular invasion (LVI) at first transurethral resection of bladder (TURBT) and radical cystectomy (RC) with survival outcomes, and to evaluate the concordance between LVI at first TURBT and RC. (2) Methods: We analyzed 216 patients who underwent first TURBT and 64 patients who underwent RC at Toho University Sakura Medical Center. (3) Results: LVI was identified in 22.7% of patients who underwent first TURBT, and in 32.8% of patients who underwent RC. Univariate analysis identified ≥cT3, metastasis and LVI at first TURBT as factors significantly associated with overall survival (OS) and cancer-specific survival (CSS). Multivariate analysis identified metastasis (hazard ratio (HR) 6.560, p = 0.009) and LVI at first TURBT (HR 9.205, p = 0.003) as significant predictors of CSS. On the other hand, in patients who underwent RC, ≥pT3, presence of G3 and LVI was significantly associated with OS and CSS in univariate analysis. Multivariate analysis identified inclusion of G3 as a significant predictor of OS and CSS. The concordance rate between LVI at first TURBT and RC was 48.0%. Patients with positive results for LVI at first TURBT and RC displayed poorer prognosis than other patients (p < 0.05). (4) Conclusions: We found that the combination of LVI at first TURBT and RC was likely to provide a more significant prognostic factor.

Preoperative Clinical Predictors of Lymphovascular Invasion of Bladder Tumors at Transurethral Resection Pathology

Background

The assessment of lymphovascular invasion (LVI) on the specimens of a transurethral resection of bladder tumors (TURBT) is very important for risk stratification and decision-making on further treatment for bladder cancer.

Objectives

The present study aimed to identify clinical predictors associated with the risk of bladder cancer with LVI before a first TURBT.

Methods

A total of 291 patients underwent a first TURBT for bladder cancer at Toho University Sakura Medical Center between January 2012 and December 2016. We analyzed predictors of LVI based on data from 217 patients and predictors of high grade and ≥ pT1 tumors based on data from the medical records of 237 patients for comparison with LVI risk factors.

Results

Univariate analysis significantly associated LVI with episodes of gross hematuria, positive urinary cytology, and larger, non-papillary and sessile tumors. Multivariate analysis selected larger tumors [odds ratio (OR) 1.39; 95 % confidence interval (CI) 1.08-1.78; p = 0.01], and non-papillary (OR 10.05; 95% CI 3.75-26.91; p < 0.01) and sessile (OR 2.65; 95% CI 1.18-5.93; p = 0.02) tumors as significant predictors of LVI. Some predictors such as tumor size and non-papillary tumors overlapped between high-grade and ≥ pT1 bladder cancer.

Conclusions

These predictors can help clinicians to identify patients with, or who are at high-risk for LVI before undergoing a first TURBT and to determine priorities for preoperative evaluation and scheduling consecutive treatments.

Left ileal conduit: A case report

INTRODUCTION

When ileal conduit construction is performed for urinary tract drainage during radical cystectomy, the conduit is usually constructed in the right lower abdomen. However, no reports have described ileal conduit construction in the left lower abdomen when it cannot be performed on the right side. In addition, some ingenuity is necessary for construction on the left.

CASE PRESENTATION

A 75-year-old woman visited our hospital with chief complaint of gross hematuria. Computed tomography and cystoscopy showed a huge bladder tumor, and blood analysis showed anemia. The patient was treated by radical cystectomy with ileal conduit construction. An ileal conduit was constructed in the left lower abdomen; it was impossible to construct in the right lower abdomen because of the abdominal wall scar hernia due to the past open surgery.

CONCLUSION

We herein reported a patient who underwent ileal conduit for urinary diversion on the left side of low abdominal wall.

Trends and oncological outcome of testosterone recovery after androgen deprivation therapy in prostate cancer patients who received external beam radiotherapy

345

Background: Although androgen deprivation therapy (ADT) combined with external beam radiation therapy (EBRT) is standard treatment for high risk prostate cancer (PC) patients, the shift of testosterone (TST) levels after ADT and the optimal duration of ADT is unclear. TST recovery and outcome were studied in PC patients who received EBRT with ADT. Methods: Eighty-two patients who underwent EBRT with ADT for PC were retrospectively analyzed. Serum TST levels after ADT terminations were studied. Cox proportional hazard models and the Kaplan-Meier method were used for statistical analysis. Results: Median age, baseline TST, nadir TST, and duration of ADT were 73 years, 456 ng/dL, 16 ng/dL, and 26 months, respectively. ADT duration of 33 months (HR 0.13; p=0.0018), nadir TST of 20 ng/dL (HR 0.35; p=0.0112), and TST >50 ng/dL at 6 months after ADT termination (HR 0.21; p=0.0075) were significantly associated with TST recovery to normal levels (200 ng/dL) on multivariate analysis. ADT duration of 33 months (HR 0.31; p=0.0023) and nadir TST of 20 ng/dL (HR 0.38; p=0.0012) were significantly associated with TST recovery to supracastrate level (50 ng/dL) on multivariate analysis. In high risk PC patients, ADT≤ 2 year group showed shorter time to TST recovery to supracastrate levels compare to those of ADT>2 year group (HR 4.21; p=0.0022) without affecting biochemical recurrence (p=0.49) and overall survival (p=0.674). Conclusions: ADT duration of 33 months and nadir TST of 20 ng/dL predicted the TST recovery to suparacastrate levels. Less than 2 year of ADT provided better TST recovery without affecting the oncological outcome in high risk patients.[Table: see text]

Detection of Nonpalpable Tiny Axillary Lymph Nodes Surrounded by Adipose Tissue Using a Near-Infrared Camera

Background: It is not always possible to detect nonpalpable small lymph nodes (LNs) surrounded by adipose tissue under the wavelength of visible light. A newly developed near-infrared camera with InGaAs element was able to capture photographs using light at >1000-nm wavelength, at which the difference in absorbance between water and lipids is large. This study investigated the ability to detect nonvisible small LNs using light at 1300-nm wavelength. Methods and Results: Following retrieval of LNs through axillary LN dissection from 20 patients with breast cancer, residual specimens were simultaneously photographed using light at 970-, 1070-, 1200-, 1300-, 1450-, and 1600-nm wavelengths. A total of 45 specimens were observed pathologically at the selected portions in which the 1300-nm light was absorbed (high absorbance group [HA group], n = 25) and those in which the 970-nm light was absorbed instead (low absorbance group [LA group], n = 20). All specimens categorized in the HA group detected the LNs, whereas none of those categorized in the LA group detected an LN. The sensitivity and specificity in the identification of an LN were 1.0. The LNs detected using this camera were significantly smaller than those detected by surgeons (3.00 ± 2.93 mm vs. 5.90 ± 3.91 mm, p < 0.01). Discussion: The light at 1300-nm wavelength was absorbed by axillary LNs. This camera detected LNs that were undetectable by surgeons. This novel technology may be applied to lymphatic microsurgery and contribute to the development of a minimally invasive LN dissection method.

Comprehensive unhealthy lifestyle is associated with alcohol consumption as J-shaped curve

Background

Alcohol consumption is a confirmed risk factor for cancer as well as cardiovascular and other diseases. Decreased and increased risks with light and heavy consumption, respectively (J-shaped associations), were reported for total mortality. However, whether alcohol itself or its related-factors are involved in this association, is unclear. This study examined the background characteristics of comprehensive lifestyles and clinical factors according to alcohol consumption, using data from a baseline survey of large-scaled cohort study conducted among the general Japanese using Breslow’s healthy lifestyle index.

Methods

The study subjects were 23,885 males and 28,165 females aged 35 to 69 years, who were enrolled in the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study. To determine unhealthy lifestyle scores, smoking, exercise, sleeping duration, breakfast consumption, eating between meals, and obesity were combined. The odds ratios (ORs) of unhealthy lifestyles and clinical factors according to alcohol consumption were estimated using a logistic regression model.

Results

The ORs of combined unhealthy lifestyles decreased among light drinkers in males (0.73, 0.67-0.80) and females (0.88, 0.82-0.95), and increased among heavy drinkers (1.52, 1.27-1.83; 2.15, 1.44-3.20, respectively). These associations were not found for each unhealthy lifestyle and atherosclerosis-related factors, except for less breakfast intake in males and less frequent habitual exercise in females.

Conclusions

The present study suggests that the J-shaped association between comprehensive unhealthy lifestyle and alcohol consumption may be an important background factor of the association between alcohol consumption and risk of total mortality. Further study for total mortality with them is warranted.

Key messages

This study showed comprehensive unhealthy lifestyles were observed not only among heavy drinkers, but also among non-drinkers. Light drinkers have more healthy lifestyles, which contribute to their better health.

Evidence-based cancer prevention recommendations for Japanese

A comprehensive evidence-based cancer prevention recommendation for Japanese was developed. We evaluated the magnitude of the associations of lifestyle factors and infection with cancer through a systematic review of the literature, meta-analysis of published data, and pooled analysis of cohort studies in Japan. Then, we judged the strength of evidence based on the consistency of the associations between exposure and cancer and biological plausibility. Important factors were extracted and summarized as an evidence-based, current cancer prevention recommendation: 'Cancer Prevention Recommendation for Japanese'. The recommendation addresses six important domains related to exposure and cancer, including smoking, alcohol drinking, diet, physical activity, body weight and infection. The next step should focus on the development of effective behavior modification programs and their implementation and dissemination.

External validation of two web-based postoperative nomograms predicting the probability of early biochemical recurrence after radical prostatectomy: a retrospective cohort study

The present study aimed to validate and compare the predictive accuracies of the Memorial Sloan Kettering Cancer Center (MSKCC) and Johns Hopkins University (JHU) web-based postoperative nomograms for predicting early biochemical recurrence (BCR) after radical prostatectomy (RP) and to analyze clinicopathological factors to predict early BCR after RP using our dataset. The c-index was 0.72 (95% confidence (CI): 0.61-0.83) for the MSKCC nomogram and 0.71 (95% CI: 0.61-0.81) for the and JHU nomogram, demonstrating fair performance in the Japanese population. Furthermore, we statistically analyzed our 174 patients to elucidate prognostic factors for early BCR within 2 years. Lymphovascular invasion (LVI) including lymphatic vessel invasion (ly) was a significant predictor of early BCR in addition to common variables (pT stage, extraprostatic extension, positive surgical margin and seminal vesicle invasion). LVI, particularly ly, may provide a good predictor of early BCR after RP and improve the accuracy of the nomograms.

Lower risk of progression from prediabetes to diabetes with health checkup with lifestyle education: Japan Ningen Dock study

BACKGROUND AND AIMS

To investigate whether the progression from prediabetes to diabetes is lower among those who undertake Ningen Dock (comprehensive health checkups with lifestyle education and doctor's consultation) than those who undertake basic mandatory occupational health checkups.

METHODS AND RESULTS

Subjects aged 30-69 years with complete annual data from 2008 to 2012 for either Ningen Dock or basic health checkups were enrolled. Subjects with prediabetes (fasting plasma glucose 100-125 mg/dl or HbA1c 5.7-6.4%) at baseline were selected (14,928 in the comprehensive group and 10,433 in the basic group). The incidence of diabetes (fasting plasma glucose ≥ 126 mg/dl, HbA1c ≥ 6.5% or taking glucose-lowering drugs) and the reduction of risk factors were compared. After 4 years, 3226 cases of diabetes occurred among 25,361 subjects with prediabetes. The incidence of diabetes was lower in the comprehensive group than the basic group (2.9 vs. 3.8 cases/100 person-years, hazard ratio 0.75, 95% confidence interval 0.68-0.81 after adjustment). Moreover, more overweight subjects controlled their body mass index (16.2% vs. 13.2%) and more began a daily exercise habit (11.8% vs. 8.5%) in the comprehensive group than in the basic group. The incidence of diabetes was lower in subjects who could control their weight or start daily exercise at year 1 in the comprehensive group.

CONCLUSION

Progression from prediabetes to diabetes was significantly lower in subjects undertaking a comprehensive health checkup with lifestyle education. Lifestyle education at health checkup for people with prediabetes might prevent progression to diabetes by reducing modifiable risk factors.

Clinical predictors for high-grade bladder cancer before first-time transurethral resection of the bladder tumor: a retrospective cohort study

The aim of this study was to identify the clinical predictors related to the risk of high-grade bladder cancer before first-time transurethral resection of the bladder tumor (TUR-Bt) and to externally validate the accuracy of Shapur's nomogram predicting the risk of high-grade bladder cancer in Japanese patients. As a result, episode of gross hematuria (odds ratio: 2.68, P = 0.02), larger tumor size (odds ratio: 1.89, P < 0.01) and positive urinary cytology (odds ratio: 8.34, P < 0.01) were found to be significant predictors for high-grade bladder cancer. Furthermore, the nomogram showed a high predictive accuracy in our Japanese population (area under the curve: 0.79). Clinicians will be able to predict high-grade bladder cancer using the common factors in Shapur's study and ours, such as tumor size and urinary cytology, and gross hematuria as the additional factor first identified here to decide priorities for the treatment of patients diagnosed with bladder cancer.

Upper-normal waist circumference is a risk marker for metabolic syndrome in normal-weight subjects

BACKGROUND AND AIMS

To elucidate implication of upper-normal waist circumference (WC), we examined whether the normal range of WC still represents a risk of metabolic syndrome (MetS) or non-adipose MetS components among normal-weight subjects.

METHODS AND RESULTS

A total of 173,510 persons (100,386 men and 73,124 women) with normal WC (<90/80 cm in men/women) and body mass index (BMI) of 18.5-24.9 were included. Subjects were categorized as having low, moderate, and upper-normal WC for those with WC < 80, 80-84, and 85-89 cm in men and <70, 70-74, and 75-79 cm in women, respectively. The prevalence of all the non-adipose MetS components (e.g. prediabetes and borderline dyslipidemia) was significantly higher in subjects with upper-normal WC on comparison with those with low WC. Overall, the prevalence of MetS (having three or more of four non-adipose MetS components) gradually increased with increasing WC (12%, 21%, and 27% in men and 11%, 14%, and 19% in women for low, moderate, and upper-normal WC, respectively). Moreover, the risk of having a greater number of MetS components increased in subjects with upper-normal WC compared with those with low WC (odds ratios for the number of one, two, three, and four MetS components: 1.29, 1.81, 2.53, and 2.47 in men and 1.16, 1.55, 1.49, and 2.20 in women, respectively).

CONCLUSION

Upper-normal WC represents a risk for acquiring a greater number of MetS components and the early stage of MetS components (prediabetes and borderline dyslipidemia), after adjusting for BMI, in a large general population with normal WC and BMI.

Bifurcation phenomena of two self-propelled camphor disks on an annular field depending on system length

Mode selection and bifurcation of a synchronized motion involving two symmetric self-propelled objects in a periodic one-dimensional domain were investigated numerically and experimentally by using camphor disks placed on an annular water channel. Newton's equation of motion for each camphor disk, whose driving force was the difference in surface tension, and a reaction-diffusion equation for camphor molecules on water were used in the numerical calculations. Among various dynamical behaviors found numerically, four kinds of synchronized motions (reversal oscillation, stop-and-move rotation, equally spaced rotation, and clustered rotation) were also observed in experiments by changing the diameter of the water channel. The mode bifurcation of these motions, including their coexistence, were clarified numerically and analytically in terms of the number density of the disk. These results suggest that the present mathematical model and the analysis of the equations can be worthwhile in understanding the characteristic features of motion, e.g., synchronization, collective motion, and their mode bifurcation.

The number of metabolic syndrome components is a good risk indicator for both early- and late-stage kidney damage

BACKGROUND AND AIMS

Renal hyperfiltration (early-stage kidney damage) and hypofiltration (late-stage kidney damage) are common in populations at high risk of chronic kidney disease. This study investigated the associations of renal hyperfiltration and hypofiltration with the number of metabolic syndrome (MetS) components.

METHODS AND RESULTS

The study subjects included 205,382 people aged 40-74 years who underwent Specific Health Checkups in Aichi Prefecture, Japan. The prevalence of renal hyperfiltration [estimated glomerular filtration rate (eGFR) above the age-/sex-specific 95th percentile] and hypofiltration (eGFR below the 5th percentile) was compared according to the number of MetS components. We found that the prevalence of both hyperfiltration and hypofiltration increased with increasing number of MetS components (odds ratios for hyperfiltration: 1.20, 1.40, 1.42, 1.41, and 1.77; odds ratios for hypofiltration: 1.07, 1.25, 1.57, 1.89, and 2.21 for one, two, three, four, and five components, respectively, compared with no MetS components). These associations were observed in both normal weight [body mass index (BMI) < 25 kg/m(2)] and overweight (BMI ≥ 25 kg/m(2)) subjects. Renal hyperfiltration was associated with prehypertension and prediabetes, while hypofiltration was associated with dyslipidemia, abdominal obesity, overt hypertension, and overt diabetes.

CONCLUSION

The number of MetS components is a good risk indicator of early- and late-stage kidney damage. Therefore, kidney function should be monitored in subjects with MetS components. MetS components should be treated as early as possible to prevent the development of kidney damage and cardiovascular diseases in people with hyperfiltration, regardless of their body weight.

A study on how a 6-month aerobic exercise program can modify coronary risk factors depending on their severity in middle-aged sedentary women

It is well known that physical exercise can reduce coronary risk factors. But how an aerobic exercise modifies coronary risk factors in relation to severity and physical fitness is still controversial.Fifty-four middle-aged women (mean age, 55 years) completed a 6-month on-site and home-based anaerobic threshold-level exercise program. The changes in coronary risk factor profiles were observed during the pre-intervention and intervention periods. Before the intervention (during control period), most coronary risk factors showed a rather unfavorable trend. After the program, their mean body weight decreased from 56.7 to 55.7 kg (p>0.05) and the proportion of body fat from 30.9 to 27.9% (p>0.05) without any reduction in lean body mass. Systolic blood pressure (SBP) decreased from 129.0 to 125.0 mm Hg (p>0.05) and diastolic blood pressure from 79.5 to 76.6 mm Hg (p>0.05). Fasting plasma glucose (FPG) declined from 109.6 to 103.4 mg/dl (p>0.05). Changes in SBP and FPG were most remarkable in their respective worst tertile. Serum lipids improved only modestly. Maximum oxygen uptake increased from 23.6 to 26.1 ml/kg/min (p>0.01). However, no significant correlations were found between changes in coronary risk factors and those in physical fitness. We conclude that the 6-month aerobic exercise program would modify women's coronary risk factors depending on their initial values, probably independently of the changes in physical fitness.

Association between body mass index and the colorectal cancer risk in Japan: pooled analysis of population-based cohort studies in Japan

BACKGROUND

Obesity has been recognized as important risk factors for colorectal cancer. However, limited evidence is available on colorectal cancer and body mass index (BMI) in Asian population.

METHODS

We conducted a pooled analysis of eight population-based prospective cohorts studies in Japan with more than 300,000 subjects to evaluate an impact of obesity in terms of BMI on colorectal cancer risk with unified categories. We estimated summary hazard ratio (HR) by pooling of study-specific HR for BMI categories with random effect model.

RESULTS

We found a significant positive association between BMI and colorectal cancer risk in male and female. Adjusted HRs for 1 kg/m(2) increase were 1.03 [95% confidence interval (CI) 1.02-1.04] for males and 1.02 (95% CI 1.00-1.03) for females. The association was stronger in colon, especially in proximal colon, relative to rectum. Males showed a stronger association than females. Population attributable fraction for colorectal cancer by BMI ≥ 25 kg/m(2) was 3.62% (95% CI 1.91-5.30) for males and 2.62% (95% CI 0.74-4.47) for females.

CONCLUSIONS

We found significant association between BMI and colorectal cancer risk by pooling of data from cohort studies with considerable number of subjects among Japanese population. This information is important in cancer control planning, especially in Asian population.

Low affinity NGF receptor (p75 neurotrophin receptor) inhibitory antibody reduces pain behavior and CGRP expression in DRG in the mouse sciatic nerve crush model

Nerve growth factor (NGF) and its low-affinity receptor, p75 neurotrophin receptor (p75 NTR), are important mediators of pain. To explore further the mechanisms involved, we examined suppression of pain behavior and expression of neuropeptides such as calcitonin gene-related peptide (CGRP) using a p75 NTR inhibitory antibody, in a mouse sciatic nerve crush model. In the nerve-injured model, 150 microg of a p75 NTR inhibitory antibody or 10 microl of saline were applied. The sciatic nerve in the sham-operated group was uninjured. Mechanical allodynia was measured for 2 weeks. CGRP and p75 NTR expression in L5 dorsal root ganglions (DRGs) was examined immunohistochemically. Mechanical allodynia was found in the two nerve injured groups, but not in the sham-operated group (p < 0.05). However, the magnitude of the mechanical allodynia was significantly decreased after application of p75 NTR inhibitory antibody (p < 0.05). CGRP and p75 NTR immunoreactivity in the L5 DRG neurons was upregulated in the injured nerve groups compared with the sham-operated group; however, p75 NTR inhibitory antibody decreased the CGRP and p75 NTR expression (p < 0.01). Application of the p75 NTR inhibitory antibody to the pinched sciatic nerve suppressed CGRP and p75 NTR expression and pain behavior.

Green tea consumption and gastric cancer in Japanese: a pooled analysis of six cohort studies

BACKGROUND

Previous experimental studies have suggested many possible anti-cancer mechanisms for green tea, but epidemiological evidence for the effect of green tea consumption on gastric cancer risk is conflicting.

OBJECTIVE

To examine the association between green tea consumption and gastric cancer.

METHODS

We analysed original data from six cohort studies that measured green tea consumption using validated questionnaires at baseline. Hazard ratios (HRs) in the individual studies were calculated, with adjustment for a common set of variables, and combined using a random-effects model.

RESULTS

During 2 285 968 person-years of follow-up for a total of 219 080 subjects, 3577 cases of gastric cancer were identified. Compared with those drinking <1 cup/day, no significant risk reduction for gastric cancer was observed with increased green tea consumption in men, even in stratified analyses by smoking status and subsite. In women, however, a significantly decreased risk was observed for those with consumption of > or =5 cups/day (multivariate-adjusted pooled HR = 0.79, 95% confidence interval (CI) = 0.65 to 0.96). This decrease was also significant for the distal subsite (HR = 0.70, 95% CI = 0.50 to 0.96). In contrast, a lack of association for proximal gastric cancer was consistently seen in both men and women.

CONCLUSIONS

Green tea may decrease the risk of distal gastric cancer in women.