Effect of baseline urinary glucose levels on the relationship between sodium-glucose cotransporter 2 inhibitors and serum uric acid in Japanese patients with type 2 diabetes mellitus

In patients with type 2 diabetes mellitus (T2DM), controlling serum uric acid (SUA) and blood glucose levels is important. Moreover, sodium-glucose cotransporter 2 (SGLT2) inhibitors decrease SUA levels by accelerating urinary uric acid excretion. We investigated the effect of baseline urinary glucose levels on the relationship between SGLT2 inhibitors and SUA levels. We conducted a retrospective observational study using the electronic medical records of patients with T2DM of Kindai University Nara Hospital (April 2013 to March 2022). We divided the patients into two groups according to their baseline urinary glucose levels: the N-UG group, which included patients with negative urinary glucose strip test results (-), and the P-UG group, which included patients with positive urinary glucose strip test results (± or more). The changes in SUA levels before and after SGLT2 inhibitor administration were investigated. For comparison, the changes in SUA levels before and after the prescription of antidiabetic agents, excluding SGLT2 inhibitors, were also investigated. Our results revealed that SGLT2 inhibitors significantly decreased the SUA levels in patients in the N-UG group but tended to decrease its levels in those in the P-UG group. Regardless of the urinary glucose status at baseline, the administration of SGLT2 inhibitors may be useful for patients with T2DM to prevent the complications of hyperuricemia.

Quantitative assessment of urinary equol levels, equol-producing bacteria, and the faecal microbiota in healthy Japanese individuals

Equol (4',7-isoflavandiol) has attracted considerable attention for its potential efficacy in treating hormonal diseases. In this study we collected samples from healthy Japanese individuals (n = 91) to observe the relationship between the abundance of equol-producing bacteria in their faeces and the concentration of equol in their urine. Quantitative polymerase chain reaction (qPCR) targeting the dihydrodaidzein reductase gene (dhdr) was used to detect equol-producing bacteria. Equol producers, who were defined as individuals with >1000 nmol/l equol in their urine, exhibited 4-8 log10 copies of dhdr/g faeces of equol-producing bacteria. We assessed the accuracy of these findings by determining the rate of correspondence between possessing equol-producing bacteria and producing urinary equol. Of the 91 participants, 33 were found to be positive for both equol-producing bacteria and urinary equol, 52 were negative for both, one was positive for equol-producing bacteria and negative for urinary equol, and five were negative for equol-producing bacteria and positive for urinary equol. The sensitivity and specificity of the qPCR for detecting equol-producing bacteria were 86.8% and 98.1%, respectively. On the whole, the presence of equol-producing bacteria and urinary equol displayed 93.4% concordance, with a kappa coefficient of 0.862. No apparent correlation was observed between dhdr copy number in the faeces and urinary equol concentrations. Analysis of the faecal microbiota showed that alpha diversity indices (OTU, ACE, Chao1, Shannon) were significantly higher in equol producers. Specifically, the relative abundance of phylum Pseudomonadota was increased in non-equol producers, while abundance of genus Alistipes, Barnesiella, Butyricimonas, Odoribacter, and Ruminococcus, which produce short chain fatty acids and/or hydrogen, were only observed in equol producers. These results suggest that a certain amount of equol-producing bacteria must be present in the intestine to produce detectable levels of equol, and that equol productivity might be affected by other components of the microbiota.

Activation of Lactate Receptor Positively Regulates Skeletal Muscle Mass in Mice

G protein-coupled receptor 81 (GPR81), a selective receptor for lactate, expresses in skeletal muscle cells, but the physiological role of GPR81 in skeletal muscle has not been fully elucidated. As it has been reported that the lactate administration induces muscle hypertrophy, the stimulation of GPR81 has been suggested to mediate muscle hypertrophy. To clarify the contribution of GPR81 activation in skeletal muscle hypertrophy, in the present study, we investigated the effect of GPR81 agonist administration on skeletal muscle mass in mice. Male C57BL/6J mice were randomly divided into control group and GPR81 agonist-administered group that received oral administration of the specific GPR81 agonist 3-Chloro-5-hydroxybenzoic acid (CHBA). In both fast-twitch plantaris and slow-twitch soleus muscles of mice, the protein expression of GPR81 was observed. Oral administration of CHBA to mice significantly increased absolute muscle weight and muscle weight relative to body weight in the two muscles. Moreover, both absolute and relative muscle protein content in the two muscles were significantly increased by CHBA administration. CHBA administration also significantly upregulated the phosphorylation level of p42/44 extracellular signal-regulated kinase-1/2 (ERK1/2) and p90 ribosomal S6 kinase (p90RSK). These observations suggest that activation of GRP81 stimulates increased the mass of two types of skeletal muscle in mice in vivo. Lactate receptor GPR81 may positively affect skeletal muscle mass through activation of ERK pathway.

Association between serum concentrations of perfluoroalkyl substances and global DNA methylation levels in peripheral blood leukocytes of Japanese women: A cross-sectional study

Global DNA methylation levels in peripheral blood leukocytes can be a biomarker for cancer risk; however, levels can be changed by various factors such as environmental pollutants. We investigated the association between serum concentrations of perfluoroalkyl substances (PFASs) and global DNA methylation levels of leukocytes in a cross-sectional study using the control group of a Japanese breast cancer case-control study [397 women with a mean age of 54.1 (SD 10.1) years]. Importantly, our analysis distinguished branched PFAS isomers as different from linear isomers. The serum concentrations of 20 PFASs were measured by in-port arylation gas-chromatography negative chemical ionization mass spectrometry. Global DNA methylation levels in peripheral blood leukocytes were measured using a luminometric methylation assay. Associations between log₁₀-transformed serum PFAS concentrations and global DNA methylation levels were evaluated by regression coefficients in multivariable robust linear regression analyses. Serum concentrations of 13 PFASs were significantly associated with increased global DNA methylation levels in leukocytes. Global DNA methylation was significantly increased by 1.45 %-3.96 % per log₁₀-unit increase of serum PFAS concentration. Our results indicate that exposure to PFASs may increase global DNA methylation levels in peripheral blood leukocytes of Japanese women.

Adverse event profiles of hypomagnesemia caused by proton pump inhibitors using the Japanese Adverse Drug Event Report (JADER) Database

Proton pump inhibitors (PPIs) are commonly used for the prevention or treatment of gastric ulcers, but they can induce hypomagnesemia. Little is known about the onset duration and risk factors related to patient characteristics of this adverse event in Japanese patients. Therefore, we analyzed the time-to-onset of PPI-induced hypomagnesemia and evaluated the association between hypomagnesemia and PPIs using the Japanese Adverse Drug Event Report (JADER) database. We analyzed hypomagnesemia cases between 2004 and 2021. The time-to-onset analysis was performed using the Weibull distribution, and the adjusted reporting odds ratio (aROR) or 95% confidence interval (95% CI) was calculated using a multiple logistic regression analysis. The analysis database comprised 236,525 cases, with 188 cases associated with hypomagnesemia. The median onset duration (interquartile range) of PPI-induced hypomagnesemia was 99.0 (51.8-285.5 ) days, which is considered the random failure type. The multiple logistic regression analysis revealed that hypomagnesemia is significantly associated with male sex (aROR, 95% CI: 1.66, 1.23-2.25) , age < 60 (1.59, 1.14-2.21) , estimated body-mass index (eBMI) (0.94, 0.91-0.98) , PPIs (1.66, 1.18-2.30) , and the interaction of age (<60)*PPIs (1.58, 1.13-2.19) . However, diuretics were not significantly associated with hypomagnesemia. Our results suggest that serum magnesium levels should be measured regularly regardless of the duration of PPI use, especially in patients with male sex, age < 60, or low BMI. These findings will assist health professionals in the adequate use of PPIs. These findings need to be evaluated by cohort studies and long-term clinical investigations.

Two-dimensional echocardiographic scoring system of the left ventricular filling pressure and clinical outcomes in heart failure with preserved ejection fraction

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Japan Society for the Promotion of Science (JSPS)

Introduction

Elevated left ventricular (LV) filling pressure in non-decompensated state is a powerful indicator of worse clinical outcomes in heart failure regardless of LV ejection fraction. However, its detection is often challenging in heart failure with preserved ejection fraction (HFpEF).

Purpose

This study aimed to elucidate the predictive value of recently proposed echocardiographic parameter of LV filling pressure, Visually assessed time difference between the Mitral valve and Tricuspid valve opening (VMT) score in HFpEF.

Methods

We retrospectively analyzed 310 well-differentiated HFpEF patients in stable conditions. Using two-dimensional echocardiographic images, time sequence of opening of mitral valve and tricuspid valve was visually assessed in the apical four-chamber view and scored to 0 to 2 (0: tricuspid valve first, 1: simultaneous, 2: mitral valve first). When the inferior vena cava diameter was dilated, 1 point was added and VMT score was calculated as four grades from 0 to 3. Based on the previous study, VMT≥2 was regarded as a sign of elevated LV filling pressure (Figure 1). LV diastolic function was graded according to the guidelines. The primary endpoint was defined as a composite of cardiac death and heart failure hospitalisation during the two years after echocardiographic examination.

Results

During the follow-up period, 55 events (18%) occurred, including four cardiac deaths and 51 heart failure hospitalisations. Kaplan-Meier curves demonstrated that VMT≥2 (n = 54) was associated with worse outcomes compared to patients showing VMT ≤ 1 (n = 256) (log-rank test P &lt;0.001). Furthermore, VMT≥2 was associated with worse outcomes when tested in 100 HFpEF patients with atrial fibrillation (log-rank test P = 0.026) (Figure 2). In the adjusted model including age, systolic blood pressure, serum albumin level, and the LV diastolic function grading, VMT≥2 was independently associated with the primary outcome (hazard ratio: 2.23; 95% confidence interval: 1.17 to 4.24, P = 0.014). Additionally, the nested regression model showed that VMT scoring provided an incremental prognostic value over clinically relevant variables (age, sex, the plasma brain natriuretic peptide level, atrial fibrillation) and LV diastolic function grading (chi-square 10.8 vs 16.3, P = 0.035).

Conclusions

In patients with HFpEF, the VMT score was independently and incrementally associated with adverse clinical outcomes. Moreover, it discriminated worse clinical outcome even in HFpEF patients with atrial fibrillation. Abstract Figure. VMT scoring  Abstract Figure. Kaplan-Meier analysis

Pathophysiological mechanism of worsened clinical outcome by lowered left ventricular cardiac power output in heart failure

Funding Acknowledgements

Type of funding sources: None.

Background

Cardiac power output (CPO) is a measure of cardiac pumping function, and CPO during exercise is known to be a powerful prognostic marker of heart failure. Despite its prognostic significance, pathophysiological mechanism of the association between reduced CPO and worse clinical outcome is unknown. We hypothesized that reduced CPO is associated with worse outcome through the reduced exercise capacity and enhanced ventilatory response.

Methods

Cardiopulmonary exercise testing and exercise stress echocardiography were performed in consecutive 64 patients with chronic heart failure who admitted to our department for the management of heart failure [60 ± 14 years old, left ventricular (LV) ejection fraction 39 ± 16%, ischemic etiology 16%, brain natriuretic peptide 124 pg/ml (51-313)]. Peak oxygen uptake (peak VO2) and the lowest minute ventilation / carbon dioxide production ratio (VE/VCO2) were measured as a parameter of exercise tolerance and that of ventilatory response, respectively. LV ejection fraction was measured by disk summation method at peak exercise. By using Doppler images, E/e" at peak exercise was measured as a marker of LV filling pressure, and CPO normalized by LV mass was obtained as 0.222 × cardiac output × mean blood pressure / LV mass [W/100 g]. Cardiac events defined as hospitalization for heart failure, cardiac death, or implantation of a LV assist device after the examinations were recorded.

Results

CPO at rest was weakly correlated with peak VO2 (r = 0.25, p = 0.046) but not with VE/VCO2. In contrast, CPO at peak exercise was positively correlated with peak VO2 (r = 0.50, p &lt; 0.001) and inversely correlated with VE/VCO2 (r=-0.40, p = 0.002). Moreover, CPO at peak exercise determined both peak VO2 (b = 0.50) and VE/VCO2 (β=-0.54) independently of LV ejection fraction and E/e" at peak exercise. During a median follow-up period of 1211 days, 12 cardiac events were observed. Each of reduced peak VO2 (hazard ratio 0.78, 95% confidence interval 0.66-0.90) and increased VE/VCO2 (hazard ratio 1.10, 95% confidence interval 1.02-1.18) was associated with worse clinical outcome.

Conclusions

In patients with chronic heart failure, CPO during exercise was associated with prognosis of heart failure through the reduced exercise capacity and enhanced ventilatory response.

Serum perfluoroalkyl substances and breast cancer risk in Japanese women: A case-control study

BACKGROUND

Perfluoroalkyl substances (PFASs) may contribute to causing breast cancer; however, associations between exposure to PFASs and risk of breast cancer are controversial.

OBJECTIVES

In the present study, we newly distinguished branched isomers of PFASs from their linear isomers and aimed to investigate the association between serum PFAS concentrations and breast cancer risk in Japanese women.

METHODS

We used a case-control design to study 405 eligible matched pairs attending four hospitals in Nagano Prefecture, Japan from May 2001 to September 2005. We used in-port arylation gas-chromatography mass spectrometry with negative chemical ionization to measure serum concentrations of 20 PFAS congeners. We calculated multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of breast cancer and its hormone-receptor subtypes by quartiles or tertiles of serum PFASs.

RESULTS

After multivariable adjustment for breast cancer risk factors, we found that serum concentrations of 20 PFAS congeners were significantly inversely associated with risk of breast cancer. Comparing the extreme quartiles of linear isomers of perfluorooctane sulfonate or perfluorooctanoic acid, ORs were 0.15 (95% CI: 0.07, 0.33 P for trend <0.0001) and 0.21 95% CI: 0.10, 0.44 P for trend <0.0001). Among postmenopausal women, whereas we found the linear isomer of perfluorotridecanoic acid to be inversely associated with breast cancer risk, a medium degree of exposure to the branched isomer of perfluorotridecanoic acid was associated with a marginally increased risk of breast cancer (OR [95% CI] = 1.74 [0.98, 3.09]).

DISCUSSION

In our case-control study, we found overall no association between serum PFAS concentrations and increased risk of breast cancer. Many inverse associations between serum PFAS concentrations and breast cancer risk were found.

Cribriform carcinoma in the lymph nodes is associated with distant metastasis, recurrence, and survival among patients with node-positive colorectal cancer

Cribriform lymph node pattern is an independent risk factor for metachronous or synchronous distant metastasis in patients with stage III and IV node-positive colorectal cancer. Multivariable analysis in patients with stage III disease indicated that the cribriform pattern of carcinoma in the lymph nodes was an independent risk factor for recurrence and survival. Kaplan–Meier analysis demonstrated that the group with stage III cribriform-type lymph node carcinoma had shorter recurrence-free and overall survival times than the stage III group with the tubular type (P &lt; 0.001).

Predictor of buckwheat allergy in children based on challenge test results: a retrospective observational study in Japan

Summary

Buckwheat (BW) is a major food allergen and one of the leading causes of food-induced anaphylaxis in Japan. The standard method of diagnosing food allergy is the oral food challenge (OFC). The BW-specific IgE (BW-sIgE) value is used to assess BW allergy but its utility is limited.The aim of the present study was to identify factors with predictive value for the diagnosis of BW allergy using the OFC.We evaluated 37 patients who were classified into the positive or negative group according to their OFC results. Ten patients (27.0%) showed objective or persistent, moderate, subjective symptoms during the OFC. The positive group had a significantly higher BW-sIgE/total IgE ratio than the negative group (p less than 0.001), but the total IgE (p = 0.139) and BW-sIgE (p = 0.130) did not differ significantly. Receiver operator characteristic (ROC) analysis showed that the BW-sIgE/total IgE ratio had a larger area under the curve (AUC, 0.885) than BW-sIgE (AUC, 0.667). The statistically optimal cut-off was 0.0058 for the BW-sIgE/total IgE ratio, which corresponded to a clinical sensitivity and specificity of 90.0% and 81.5%, respectively.BW-s IgE/total IgE ratio may be more useful predictor of BW OFC results than BW-s IgE.

The disease sites of female genital cancers of BRCA1/2-associated hereditary breast and ovarian cancer: a retrospective study

Disease sites of female genital tract cancers of BRCA1/2-associated hereditary breast and ovarian cancer (HBOC) are less understood than non-hereditary cancers. We aimed to elucidate the disease site distribution of genital cancers in women with the germline BRCA1 and BRCA2 pathogenic variants (BRCA1+ and BRCA2+) of HBOC. For the primary disease site, the proportion of fallopian tube and peritoneal cancer was significantly higher in BRCA2+ (40.5%) compared with BRCA1+ (15.4%) and BRCA− (no pathogenic variant, 12.8%). For the metastatic site, the proportion of peritoneal dissemination was significantly higher in BRCA1+ (71.9%) than BRCA− (55.1%) and not different from BRCA2+ (71.4%). With one of the most extensive patients, this study supported the previous reports showing that the pathogenic variants of BRCA1/2 were involved in the female genitalia’s disease sites.

Risk factors for lymph node metastasis of ovarian, fallopian tube and primary peritoneal cancer in hereditary breast and ovarian cancer syndrome

BACKGROUND

To establish an individualized surgical strategy for lymphadenectomy in ovarian cancer patients with the germline BRCA1 and BRCA2 pathogenic variants (BRCA1+ and BRCA2+), we investigated the clinicopathological characteristics that are involved in the increased risk of lymph node metastasis.

METHODS

We retrospectively reviewed the data of Japanese women registered in the database of the Japanese Hereditary Breast and Ovarian Cancer Consortium, who underwent BRCA1 and BRCA2 genetic testing.

RESULTS

We evaluated the predictors of lymph node metastasis in all patients with the information of age at the diagnosis, disease site, histological subtype, 2014 FIGO stage, personal breast cancer history and family history; 233, 153 and 32 patients in the BRCA- (no pathogenic variant), BRCA1+ and BRCA2+ groups, respectively. The prevalence of lymph node metastasis was not markedly different between BRCA- (20.0%), BRCA1+ (18.4%) and BRCA2+ (26.2%). Multivariate analysis revealed an absence of a family history of ovarian cancer as an independent predictor for an increased risk of lymph node metastasis in BRCA1+, and the prevalence of lymph node metastasis was 11.7 and 42.0% in the groups with and without a family history of ovarian cancer, respectively. This subgroup without a family history of ovarian cancer did not show any correlation with a particular variant of BRCA1, including two common variants of c.188 T > A and c.2800C > T.

CONCLUSIONS

This study suggested that certain genetic factors related to the penetrance of hereditary breast and ovarian cancer syndrome altered the frequency of lymph node metastasis in BRCA1+ ovarian cancer, and family history may be useful to personalize the indication of lymphadenectomy.

Simple echocardiographic scoring system to estimate left ventricular filling pressure based on visual assessment of time sequence of mitral and tricuspid valve opening

Introduction

In the presence of elevated left ventricular (LV) filling pressure, mitral valve (MV) becomes to open early and precedes tricuspid valve (TV) opening in early diastole. Accordingly, time-delay of right ventricular inflow relative to LV inflow assessed by dual Doppler system was recently reported as a parameter of LV filling pressure. We assumed that visually-assessed time-delay of TV relative to MV opening could be a simple and alternative marker of elevated LV filling pressure.

Purpose

This study aimed to elucidate the clinical usefulness of the 2-dimensional echocardiographic scoring system, Visual assessment of time-difference between Mitral and Tricuspid valve opening (VMT) score, in patients with heart failure (HF).

Methods

We analyzed 119 consecutive HF patients who underwent echocardiography and cardiac catheterization within a day. Elevated LV filling pressure was defined as mean pulmonary arterial wedge pressure (PAWP) ≥15 mmHg. LV diastolic function was graded according to the ASE/EACVI recommendations. Time sequence of opening of MV and TV was visually assessed in the apical 4-chamber view and scored to 3 grades (0: TV opening first, 1: simultaneous, 2: MV opening first). When the inferior vena cava diameter was &gt;21 mm and collapsed &lt;20% during normal respiration, 1 point was added and VMT score was calculated as 4 grades from 0 to 3. We also investigated 113 patients without worsening HF at VMT scoring for cardiac events defined as worsening HF, LV assist device implantation, or cardiac death for 1 year after the echocardiography.

Results

VMT was scored as 0 in 20 patients, 1 in 50 patients, 2 in 37 patients, and 3 in 12 patients. PAWP was elevated in patients with VMT score of 2 and 3 (0: 10±5, 1: 12±4, 2: 22±8, 3: 28±4 mmHg, ANOVA P&lt;0.001) (Figure). In overall patients, VMT≥2 predicted elevated PAWP with accuracy of 86%. When the accuracy was tested in patients with reduced (&lt;40%, HFrEF) and preserved LV ejection fraction (≥40%) respectively, the accuracy was excellent in HFrEF (96% and 77%, respectively). Importantly, VMT≥2 also had good accuracy of 82% for elevated PAWP in 33 patients in whom recommendations usually cannot grade diastolic function due to monophasic LV inflow. In the sequential Cox models, the addition of VMT score to the model including the plasma brain natriuretic peptide (BNP) level and LV diastolic grading improved the predictive power for elevated PAWP (P&lt;0.001). During the follow-up, 20 cardiac events were observed (6 worsening HF, 9 LV assist device implantation and 5 cardiac death). Kaplan-Meier analysis showed that the patients with VMT≥2 were at higher risk of cardiac events than those with VMT≤1 (log-rank test P&lt;0.001) (Figure).

Conclusions

The VMT score was a simple and accurate marker of elevated LV filling pressure and has an incremental benefit over BNP and LV diastolic function grading. Moreover, it could be a novel prognostic marker in patients with HF.

Figure 1

Funding Acknowledgement

Type of funding source: None

The relationship between BRCA-associated breast cancer and age factors: an analysis of the Japanese HBOC consortium database

BRCA1/2 pathogenic variant prevalence in Japanese breast cancer is unclear. Here, we analyzed BRCA1/2 pathogenic variant prevalence with a particular focus on age factors, using the Japanese HBOC consortium database. All registered subjects were Japanese individuals who underwent BRCA1/2 genetic testing from January 1996 to July 2017 according to the Japanese HBOC consortium database. Cases were extracted and analyzed for each evaluation item. Overall BRCA1 and BRCA2 pathogenic variant prevalence was 11.2% and 9.0% in the cohort of 2366 proband patients, respectively. The age at onset of breast cancer for patients with BRCA1/2 pathogenic variants was significantly lower than that for patients without a BRCA1/2 pathogenic variant. In both BRCA1/2 patients, ages at onset were not statistically significantly different between two subtype groups (ER-positive vs. TNBC). We analyzed the BRCA1/2 pathogenic variant prevalence among age groups in patients with no family history of breast or ovarian cancer. In the TNBC group, the rate of genetic variants was more frequent among younger patients. Our results demonstrated that early breast cancer onset is associated with a BRCA1/2 pathogenic variant in the Japanese population. Younger TNBC patients were more likely to have a BRCA1/2 pathogenic variant irrespective of a family history of breast or ovarian cancer.

Incidence of contralateral and ipsilateral breast cancers and prognosis in BRCA1/2 pathogenic variant carriers based on the Japanese HBOC Consortium registration

This study aimed to clarify the breast cancer prognosis in Japanese patients with BRCA1/2 pathogenic variant. We analyzed 2235 women with breast cancer who underwent BRCA1/2 genetic testing between 1996 and 2018 using data from the Japanese hereditary breast and ovarian cancer syndrome registry. The cumulative risk for contralateral and ipsilateral breast cancers and time to death since the first breast cancer were stratified based on the BRCA1/2 variant status. The median follow-up was 3.0 years (0.1-34.1 years) after the first breast cancer. The annual average risks of contralateral breast cancer in BRCA1 and BRCA2 and non-BRCA1/2 pathogenic variant carriers were 4.0%, 2.9%, and 1.9%, respectively (P = 0.001). The annual average risks of ipsilateral breast cancer in the three groups were 2.7%, 1.4%, and 1.1%, respectively (P = 0.06). BRCA1 pathogenic variant carriers had significantly higher risks of contralateral (hazard ratio 1.91, P < 0.001) and ipsilateral (hazard ratio 2.00, P = 0.02) breast cancers than non-BRCA1/2 pathogenic variant carriers. The time to death by the BRCA1/2 variant status was not significantly difference (P = 0.28). The prognosis of breast cancer patients who received standard treatment was comparable regardless of the BRCA1/2 variant status.

A Retrospective Analysis of the Relationship Between the Result of BRCA1/2 Genetic Testing and Surgical Method Selection in Japan

BACKGROUND

We studied the extent of BRCA1/2 genetic testing to help select the surgical approach for patients with breast cancer in Japan remains unclear.

PATIENTS AND METHODS

The study subjects were female patients with primary unilateral invasive breast cancer considered as candidates for breast-conserving surgery who underwent preoperative BRCA1/2 genetic testing. A retrospective analysis was performed on the results of BRCA1/2 genetic testing and surgical method selection using national registration data from the Japanese Hereditary Breast and Ovarian Cancer Syndrome Consortium.

RESULTS

Our study included 318 female patients. Among these patients, 23.7% of patients with BRCA1/2 mutations and 61.8% of patients without these variants underwent breast-conserving surgery (P < .01). Among the patients with BRCA1/2 mutations, those who chose breast-conserving surgery tended not to undergo risk-reducing salpingo-oophorectomy (P < .05). Among the patients with BRCA1/2 mutations who underwent mastectomy for the affected side, 31.8% received contralateral risk-reducing mastectomy. Patients diagnosed with breast cancer under the age of 50 years were more likely to have contralateral risk-reducing mastectomy than patients over the age 50 years (P < .05).

CONCLUSIONS

Patients with BRCA1/2 mutations tend to choose mastectomy. However, it is speculated that the final surgical method selection is made in consideration of not only the test results but also with careful consideration of the patient, taking into account other factors including individual values for risk-reducing surgeries and the age of breast cancer onset.

Prevalence of disease-causing genes in Japanese patients with BRCA1/2-wildtype hereditary breast and ovarian cancer syndrome

Panel sequencing of susceptibility genes for hereditary breast and ovarian cancer (HBOC) syndrome has uncovered numerous germline variants; however, their pathogenic relevance and ethnic diversity remain unclear. Here, we examined the prevalence of germline variants among 568 Japanese patients with BRCA1/2-wildtype HBOC syndrome and a strong family history. Pathogenic or likely pathogenic variants were identified on 12 causal genes for 37 cases (6.5%), with recurrence for 4 SNVs/indels and 1 CNV. Comparisons with non-cancer east-Asian populations and European familial breast cancer cohorts revealed significant enrichment of PALB2, BARD1, and BLM mutations. Younger onset was associated with but not predictive of these mutations. Significant somatic loss-of-function alterations were confirmed on the wildtype alleles of genes with germline mutations, including PALB2 additional somatic truncations. This study highlights Japanese-associated germline mutations among patients with BRCA1/2 wildtype HBOC syndrome and a strong family history, and provides evidence for the medical care of this high-risk population.

Analysis of clinical characteristics of breast cancer patients with the Japanese founder mutation BRCA1 L63X

Background: BRCA1 and BRCA2 are high-penetrance inherited genes; different founder mutations have been reported in various areas and races. By using trial registration data from the Japanese hereditary breast and ovarian cancer syndrome (HBOC) consortium, we aimed to explore the clinicopathological characteristics of breast cancer patients with the Japanese founder mutation BRCA1 L63X. Results: We found 88 BRCA1 carriers, 76 BRCA2 carriers, and one carrier of both BRCA1 and BRCA2. Of 46 independent BRCA1 mutations, the BRCA1 L63X mutation was detected in 26 patients. We observed a significant difference in the proportion of triple-negative breast cancer phenotype among 88.9%, 72.5%, and 26.8% of BRCA1 L63X mutation, BRCA1 mutation, and BRCA2 mutation carriers, respectively (p < .001). Additionally, significant differences were also observed in nuclear grade in the resultant breast cancer between the groups (p < .001). Conclusions: A high proportion of Japanese HBOC patients showed the BRCA1 L63X mutation, and the clinical characteristics of breast cancer in patients with this mutation might differ from those in patients with other BRCA1 or BRCA2 mutations, in terms of the subtype and nuclear grade of the resultant cancer. Methods: From 827 patients in the Japanese HBOC consortium through August 2015, patients with BRCA1/2 mutations were included in this study. We compared the clinicopathological features among patients with BRCA1 L63X mutation, other BRCA1 mutations, and BRCA2 mutations using Chi-square test.

Color change in Perlodel® tablets induced by LED lighting - photolysis of bromocriptine mesylate

Various types of fluorescent lights are found in the dispensing rooms of medical facilities, such as hospitals and pharmacies, in Japan. However, to reduce electric power consumption, it was necessary to evaluate the substitution of fluorescent lighting with light emitting diode (LED) lighting, which has become widespread in recent years. We subjectively evaluated several types of medicines stored under various light sources and found that different color changes were induced in tablets. In this study, we focused on Perlodel ® tablets, containing 2.5 mg bromocriptine mesylate, as an example for the objective evaluation of the differences in the color change of tablets when stored under LED lighting and fluorescent lighting. High-performance liquid chromatography (HPLC) analysis of part of the tablet surface area revealed a change from white to light brown or dark brown after 28 days of irradiation, with a residual concentration of bromocriptine mesylate of 85.5 % under fluorescent lighting, 85.6 % under daylight-color LED lighting, 90.3 % under bulb-color LED lighting, and 99.2 % in the dark. In addition, the ultraviolet (UV)-visible spectral study of the absorbance of a photo-product at 400-550 nm indicated that the color change of the Perlodel^® 2.5 mg tablet was caused by photochemical degradation of bromocriptine mesylate. Thus, this analysis of the photochemical changes in drugs stored under different light sources demonstrated the potency of LED lights. Through the objective evaluation of the color change, the cause of the color change was determined; this will allow us to develop a strategy that minimizes possible disadvantages to patients, such as a decrease in treatment efficacy owing to decomposition of the main component or adverse caused by decomposed matter.

An open-type microdevice to improve the quality of fluorescence labeling for axonal transport analysis in neurons

Abnormal axonal transport of vesicles as well as organelles in a particular set of neurons is implicated in the pathogenesis of many neurodegenerative diseases such as amyotrophic lateral sclerosis, Alzheimer's disease, and Parkinson's disease. Although various types of microfluidic multicompartmental devices with closed microchannels have been recently developed and widely used for axonal transport analysis, most of the existing devices are troublesome and time-consuming to handle, such as culture maintenances, sample collections, and immunocytochemistry. In this study, we overcome such inherent shortcomings by developing a novel open-type device that enables easy cell maintenance and sample collections. In our device, microgrooves instead of microchannels were directly fabricated on a glass substrate, thereby making possible a high-resolution optical observation. Compared with the conventional closed-type devices, our newly designed device allowed us to efficiently and precisely label the axonal acidic vesicles by fluorescent dyes, facilitating a high-throughput analysis of axonal vesicular transport. The present novel device, as a user-friendly and powerful tool, can be implemented in molecular and cellular pathogenesis studies on neurological diseases.

Risk factors increasing blood pressure in Japanese colorectal cancer patients treated with bevacizumab

Bevacizumab has been reported to increase blood pressure. However, the factors, including patient characteristics and laboratory data contributing to this side effect remain unclear. Therefore, we investigated the relationships between increased blood pressure and bevacizumab administration, patient characteristics, and laboratory data. Between April 2007 and January 2018, factor analysis was retrospectively conducted by monitoring increases in blood pressure, the status of bevacizumab administration, patient characteristics, and laboratory data before the first administration in Japanese patients with colorectal cancer who satisfied the criteria for this study. Sixty-seven patients were included, 34 of whom (50.7%) had an increase in blood pressure after bevacizumab administration. On univariate analysis, liver metastasis, antihypertensive drug use, systolic blood pressure at rest before the first bevacizumab administration, body mass index, creatinine, and blood platelet count were significantly different between the two groups. Multivariate analysis was conducted using increased blood pressure as an objective variable and the factors extracted by the univariate analysis as explanatory variables. The results suggested that liver metastasis, antihypertensive drugs, systolic blood pressure at rest before the first bevacizumab administration, and creatinine were associated with the increase in blood pressure. Furthermore, a log-rank test performed based on Kaplan-Meier curves demonstrated that liver metastasis in patients not taking antihypertensive drugs and antihypertensive drug use in patients without liver metastasis were significantly associated with increased blood pressure. Additionally, liver metastasis in patients with antihypertensive drug use was significantly associated with increased blood pressure. Our findings suggest that liver metastasis and antihypertensive drug use, which was previously reported, are risk factors for increased blood pressure.

MENS-associated increase of muscular protein content via modulation of caveolin-3 and TRIM72

Microcurrent electrical neuromuscular stimulation (MENS) is known as an extracellular stimulus for the regeneration of injured skeletal muscle in sports medicine. However, the effects of MENS-associated increase in muscle protein content are not fully clarified. The purpose of this study was to investigate the effects of MENS on the muscular protein content, intracellular signals, and the expression level of caveolin-3 (Cav-3), tripartite motif-containing 72 (TRIM72) and MM isoenzyme of creatine kinase (CK-MM) in skeletal muscle using cell culture system. C2C12 myotubes on the 7th day of differentiation phase were treated with MENS (intensity: 10-20 microA, frequency: 0.3 Hz, pulse width: 250 ms, stimulation time: 15-120 min). MENS-associated increase in the protein content of myotubes was observed, compared to the untreated control level. MENS upregulated the expression of Cav-3, TRIM72, and CK-MM in myotubes. A transient increase in phosphorylation level of Akt was also observed. However, MENS had no effect on the phosphorylation level of p42/44 extracellular signal-regulated kinase-1/2 and 5'AMP-activated protein kinase. MENS may increase muscle protein content accompanied with a transient activation of Akt and the upregulation of Cav-3 and TRIM72.

Lactate increases myotube diameter via activation of MEK/ERK pathway in C2C12 cells

AIM

Lactate is produced in and released from skeletal muscle cells. Lactate receptor, G-protein-coupled receptor 81 (GPR81), is expressed in skeletal muscle cells. However, a physiological role of extracellular lactate on skeletal muscle is not fully clarified. The purpose of this study was to investigate extracellular lactate-associated morphological changes and intracellular signals in C2C12 skeletal muscle cells.

METHODS

Mouse myoblast C2C12 cells were differentiated for 5 days to form myotubes. Sodium lactate (lactate) or GPR81 agonist, 3,5-dihydroxybenzoic acid (3,5-DHBA), was administered to the differentiation medium.

RESULTS

Lactate administration increased the diameter of C2C12 myotubes in a dose-dependent manner. Administration of 3,5-DHBA also increased myotube diameter. Not only lactate but also 3,5-DHBA upregulated the phosphorylation level of mitogen-activated protein kinase kinase 1/2 (MEK1/2), p42/44 extracellular signal-regulated kinase-1/2 (ERK1/2) and p90 ribosomal S6 kinase (p90RSK). MEK inhibitor U0126 depressed the phosphorylation of ERK-p90RSK and increase in myotube diameter induced by lactate. On the other hand, both lactate and 3,5-DHBA failed to induce significant responses in the phosphorylation level of Akt, mammalian target of rapamycin, p70 S6 kinase and protein degradation-related signals.

CONCLUSION

These observations suggest that lactate-associated increase in the diameter of C2C12 myotubes is induced via activation of GRP81-mediated MEK/ERK pathway. Extracellular lactate might have a positive effect on skeletal muscle size.

Changes in resting-state brain networks after cognitive-behavioral therapy for chronic pain

BACKGROUND

Cognitive-behavioral therapy (CBT) is thought to be useful for chronic pain, with the pathology of the latter being closely associated with cognitive-emotional components. However, there are few resting-state functional magnetic resonance imaging (R-fMRI) studies. We used the independent component analysis method to examine neural changes after CBT and to assess whether brain regions predict treatment response.

METHODS

We performed R-fMRI on a group of 29 chronic pain (somatoform pain disorder) patients and 30 age-matched healthy controls (T1). Patients were enrolled in a weekly 12-session group CBT (T2). We assessed selected regions of interest that exhibited differences in intrinsic connectivity network (ICN) connectivity strength between the patients and controls at T1, and compared T1 and T2. We also examined the correlations between treatment effects and rs-fMRI data.

RESULTS

Abnormal ICN connectivity of the orbitofrontal cortex (OFC) and inferior parietal lobule within the dorsal attention network (DAN) and of the paracentral lobule within the sensorimotor network in patients with chronic pain normalized after CBT. Higher ICN connectivity strength in the OFC indicated greater improvements in pain intensity. Furthermore, ICN connectivity strength in the dorsal posterior cingulate cortex (PCC) within the DAN at T1 was negatively correlated with CBT-related clinical improvements.

CONCLUSIONS

We conclude that the OFC is crucial for CBT-related improvement of pain intensity, and that the dorsal PCC activation at pretreatment also plays an important role in improvement of clinical symptoms via CBT.

Reappraisal of classification of distal cholangiocarcinoma based on tumour depth

Background

In the eighth edition of the AJCC cancer staging classification, the T system for distal cholangiocarcinoma (DCC) has been revised from a layer-based to a depth-based approach. The aim of this study was to propose an optimal T classification using a measured depth in resectable DCC.

Methods

Patients who underwent pancreatoduodenectomy for DCC at 32 hospitals between 2001 and 2010 were included. The distance between the level of the naive bile duct and the deepest cancer cells was measured as depth of invasion (DOI). Invasive cancer foci were measured as invasive tumour thickness (ITT). Log rank χ2 scores were used to determine the cut-off points, and concordance index (C-index) to assess the survival discrimination of each T system.

Results

Among 404 patients, DOI was measurable in 182 (45·0 per cent) and ITT was measurable in all patients, with median values of 2·3 and 5·6 mm respectively. ITT showed a positive correlation with DOI (rs = 0·854, P &lt; 0·001), and the cut-off points for prognosis were 1, 5 and 10 mm. Median survival time was shorter with increased ITT: 12·4 years for ITT below 1 mm, 5·2 years for ITT at least 1 mm but less than 5 mm, 3·0 years for ITT at least 5 mm but less than 10 mm, and 1·5 years for ITT 10 mm or more (P &lt; 0·001). This classification exhibited more favourable prognostic discrimination than the T systems of the seventh and eighth editions of the AJCC (C-index 0·646, 0·622 and 0·624 respectively).

Conclusion

ITT is an accurate approach for depth assessment in DCC. The four-tier ITT classification with cut-off points of 1, 5 and 10 mm seems to be a better T system than those in the seventh and eighth editions of the AJCC classification.

Abstract PD1-09: High incidence rate of occult cancer in risk reducing mastectomy specimens despite thorough assessment with breast MRI and ultrasound-findings from the hereditary breast and ovarian cancer registration 2016 in Japan

Introduction:One of the preemptive strategies for Hereditary Breast and Ovarian Cancer (HBOC) is prophylactic surgery. Data for risk reducing mastectomy (RRM) clearly showed a risk reduction of more than 90% for breast cancer.

Method: We report here the statistical results of the HBOC registration up to 2016. The subjects of this study were those who underwent BRCA1/2 genetic testing during the study period, at 7 medical institutions.

Results: A total of 1527 probands underwent BRCA testing; 1125 cases (73.7%) were negative for BRCA1/2 mutation, and 297 cases (19.5%) were positive, while 105 cases (6.9%) had uncertain results. Among the 297 cases with positive results, 157 cases (10.3%) were positive for BRCA1, 139 cases (9.1%) for BRCA2, and 1 case (0.1%) was positive for both.The mean age at breast cancer diagnosis was 41.7 years in BRCA1/2 mutation positive and 45.8 years in negative cases. In comparison to the National Registration for Breast Cancer Incidence 2011 in Japan (n=72,472), breast cancer with BRCA mutations occurred at a younger age. Among 359 cases of triple negative breast cancer, 101 cases (28.3%) were BRCA1 mutation positive while 18 cases (5.0%) were BRCA2 mutation positive.

Three hundred seventy cases underwent genetic testing prior to surgery, as a deciding factor for the surgical procedure. Among BRCA mutation positive cases, 58 cases (87.9%) chose to undergo total mastectomy, and 8 cases (12.1%) chose breast conserving surgery (BCS); on the other hand, 141 cases (46.4%) of BRCA mutation negative cases chose total mastectomy and 158 cases (52.0%) chose BCS.

Four cases of new onset breast cancers were observed among the 55 cases of previvors (mean observation period: 2.5 years; incidence rate: 2.9%/Y). Among the 73 BRCA1/2 mutation positive women who underwent BCS, 3 ipsilateral breast cancer cases were observed (mean observation period: 3.5 years; incidence rate: 1.2%/Y), while 2 cases were noted among 477 cases of BRCA1/2 mutation negative cases (mean observation period: 2.2 years; incidence rate: 0.2%/Y). Of 189 BRCA1/2 mutation positive cases with unilateral breast cancer, 8 contralateral breast cancer cases were noted (mean observation period: 3.0 years; incidence rate: 1.4%/Y), while 4 cases of contralateral breast cancer were observed among 892 cases of BRCA1/2 mutation negative cases (mean observation period: 2.2 years; incidence rate: 0.2%/Y).

Fifty-one patients had undergone RRM.Six cases (11.8%) of occult breast cancer were noted in the RRM specimens, among which 2 were BRCA1 positive cases and 4 were BRCA2 positive cases. All of these six cases had undergone extensive imaging work-up prior to surgery by using mammography, ultrasound and breast MRI.

Conclusions: The incidence rate of occult cancer after risk-reducing mastectomy was reported to be about 5% in the high-risk population. Our report showed a relatively higher incidence rate of occult cancer at 11.8% among BRCA mutation positive cases, despite thorough pre-operative radiological evaluations, which included a breast MRI. These results suggest the limitations in the use of MRI for the surveillance of patients with BRCA mutations.

Citation Format: Yamauchi H, Okawa M, Yokoyama S, Nakamura S, Arai M. High incidence rate of occult cancer in risk reducing mastectomy specimens despite thorough assessment with breast MRI and ultrasound-findings from the hereditary breast and ovarian cancer registration 2016 in Japan [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD1-09.

Effects of behavioural activation on the neural basis of other perspective self-referential processing in subthreshold depression: a functional magnetic resonance imaging study

BACKGROUND

It has been demonstrated that negatively distorted self-referential processing, in which individuals evaluate one's own self, is a pathogenic mechanism in subthreshold depression that has a considerable impact on the quality of life and carries an elevated risk of developing major depression. Behavioural activation (BA) is an effective intervention for depression, including subthreshold depression. However, brain mechanisms underlying BA are not fully understood. We sought to examine the effect of BA on neural activation during other perspective self-referential processing in subthreshold depression.

METHOD

A total of 56 subjects underwent functional magnetic resonance imaging scans during a self-referential task with two viewpoints (self/other) and two emotional valences (positive/negative) on two occasions. Between scans, while the intervention group (n = 27) received BA therapy, the control group (n = 29) did not.

RESULTS

The intervention group showed improvement in depressive symptoms, increased activation in the dorsal medial prefrontal cortex (dmPFC), and increased reaction times during other perspective self-referential processing for positive words after the intervention. Also, there was a positive correlation between increased activation in the dmPFC and improvement of depressive symptoms. Additionally, there was a positive correlation between improvement of depressive symptoms and increased reaction times.

CONCLUSIONS

BA increased dmPFC activation during other perspective self-referential processing with improvement of depressive symptoms and increased reaction times which were associated with improvement of self-monitoring function. Our results suggest that BA improved depressive symptoms and objective monitoring function for subthreshold depression.

Heat shock transcription factor 1-associated expression of slow myosin heavy chain in mouse soleus muscle in response to unloading with or without reloading

AIM

The effects of heat shock transcription factor 1 (HSF1) deficiency on the fibre type composition and the expression level of nuclear factor of activated T cells (NFAT) family members (NFATc1, NFATc2, NFATc3 and NFATc4), phosphorylated glycogen synthase kinase 3α (p-GSK3α) and p-GSK3β, microRNA-208b (miR-208b), miR-499 and slow myosin heavy chain (MyHC) mRNAs (Myh7 and Myh7b) of antigravitational soleus muscle in response to unloading with or without reloading were investigated.

METHODS

HSF1-null and wild-type mice were subjected to continuous 2-week hindlimb suspension followed by 2- or 4-week ambulation recovery.

RESULTS

In wild-type mice, the relative population of slow type I fibres, the expression level of NFATc2, p-GSK3 (α and β), miR-208b, miR-499 and slow MyHC mRNAs (Myh7 and Myh7b) were all decreased with hindlimb suspension, but recovered after it. Significant interactions between train and time (the relative population of slow type I fibres; P = 0.01, the expression level of NFATc2; P = 0.001, p-GSKβ; P = 0.009, miR-208b; P = 0.002, miR-499; P = 0.04) suggested that these responses were suppressed in HSF1-null mice.

CONCLUSION

HSF1 may be a molecule in the regulation of the expression of slow MyHC as well as miR-208b, miR-499, NFATc2 and p-GSK3 (α and β) in mouse soleus muscle.

Deficiency of heat shock transcription factor 1 suppresses heat stress-associated increase in slow soleus muscle mass of mice

AIM

Effects of heat shock transcription factor 1 (HSF1) deficiency on heat stress-associated increase in slow soleus muscle mass of mice were investigated.

METHODS

Both HSF1-null and wild-type mice were randomly assigned to control and heat-stressed groups. Mice in heat-stressed group were exposed to heat stress (41 °C for 60 min) in an incubator without anaesthesia.

RESULTS

Significant increase in wet and dry weights, and protein content of soleus muscle in wild-type mice was observed seven days after the application of the heat stress. However, heat stress had no impact on soleus muscle mass in HSF1-null mice. Neither type of mice exhibited much effect of heat stress on HSF mRNA expression (HSF1, HSF2 and HSF4). On the other hand, heat stress upregulated heat shock proteins (HSPs) at the mRNA (HSP72) and protein (HSP72 and HSP110) levels in wild-type mice, but not in HSF1-null mice. The population of Pax7-positive nuclei relative to total myonuclei of soleus muscle in wild-type mice was significantly increased by heat stress, but not in HSF1-null mice. Furthermore, the absence of HSF1 gene suppressed heat stress-associated phosphorylation of Akt and p70 S6 kinase (p-p70S6K) in soleus muscle.

CONCLUSION

Heat stress-associated increase in skeletal muscle mass may be induced by HSF1 and/or HSF1-mediated stress response that activates muscle satellite cells and Akt/p70S6K signalling pathway.

Questionable expression of unstable DQ heterodimer containing HLA-DQA1*01:07

Human leukocyte antigens (HLA)-DQA1*01:07 was identified as an HLA-DQ blank specificity that segregated with the serological HLA-A2, -B7, -DR14, -DR52 haplotype, which carried DQB1*05:03. The blank specificity of DQA1*01:07-DQB1*05:03 may be because of lack of reactivity of available typing sera, or disruption of proper assembly of DQ heterodimer. The cDNA sequence of DQA1*01:07 is nearly identical to DQA1*01:04 except for a variant at position 304, which results in the replacement of an arginine with a cysteine at 79α. To determine whether the DQA1*01:07 product can be expressed on cell-surface, we co-expressed DQA1*01:07 with various DQB1*05 or *06 alleles in fibroblast cells. Cell-surface expression of DQ was detectable when DQA1*01:07 was co-expressed with DQB1*06:04 but undetectable with other DQB1*05 and DQB1*06 alleles, including DQB1*05:03, to which DQA1*01:07 was encoded in cis. These data suggest that DQA1*01:07 may act as a phenotypically null allele in the DQA1*01:07-DQB1*05:03 haplotype, while it can be expressed at a low level in the presences of certain DQB1*06 alleles, such as DQB1*06:04, in trans. Based on the null or low expression of DQA1*01:07 as shown in the previous and present studies, DQA1*01:07 has recently been renamed to DQA1*01:07Q, indicating its questionable expression.

Randomized clinical trial of defaecatory function after anterior resection for rectal cancer with high versus low ligation of the inferior mesenteric artery

Background

Defaecatory function is often poor after anterior resection. Denervation of the neorectum following high ligation of the inferior mesenteric artery (IMA) is a possible cause of impaired defaecatory function. The purpose of this randomized clinical trial was to clarify whether the level of ligation of the IMA in patients with rectal cancer affects defaecatory function.

Methods

Between 2008 and 2011, patients who underwent anterior resection for rectal cancer were randomized to receive either high or low ligation of the IMA. The primary endpoint was to demonstrate the superiority of low ligation in terms of defaecatory function.

Results

One hundred patients were enrolled in the study; 51 were randomized to high ligation of the IMA and 49 to low ligation. There were no differences between the groups in terms of clinical data, except tumour stage, which was more advanced in the high-ligation group (P = 0·046). Nor were there any differences in defaecatory function, self-assessment of defaecation, Faecal Incontinence Quality of Life scale or continence score between groups at 3 months and 1 year. The number of harvested lymph nodes was similar. The rate of symptomatic anastomotic leakage was 16 per cent in the high-ligation group and 10 per cent in the low-ligation group (P = 0·415).

Conclusion

The level of ligation of the IMA in patients with rectal cancer did not affect defaecatory function or the incidence of postoperative complications. Registration number: NCT00701012 (http://www.clinicaltrials.gov).