The impact of rare cancer and early-line treatments on the benefit of comprehensive genome profiling-based precision oncology

BACKGROUND

Comprehensive genome profiling (CGP) serves as a guide for suitable genomically matched therapies for patients with cancer. However, little is known about the impact of the timing and types of cancer on the therapeutic benefit of CGP.

MATERIALS AND METHODS

A single hospital-based pan-cancer prospective study (TOP-GEAR; UMIN000011141) was conducted to examine the benefit of CGP with respect to the timing and types of cancer. Patients with advanced solid tumors (>30 types) who either progressed with or without standard treatments were genotyped using a single CGP test. The subjects were followed up for a median duration of 590 days to examine therapeutic response, using progression-free survival (PFS), PFS ratio, and factors associated with therapeutic response.

RESULTS

Among the 507 patients, 62 (12.2%) received matched therapies with an overall response rate (ORR) of 32.3%. The PFS ratios (≥1.3) were observed in 46.3% (19/41) of the evaluated patients. The proportion of subjects receiving such therapies in the rare cancer cohort was lower than that in the non-rare cancer cohort (9.6% and 17.4%, respectively; P = 0.010). However, ORR of the rare cancer patients was higher than that in the non-rare cancer cohort (43.8% and 20.0%, respectively; P = 0.046). Moreover, ORR of matched therapies in the first or second line after receiving the CGP test was higher than that in the third or later lines (62.5% and 21.7%, respectively; P = 0.003). Rare cancer and early-line treatment were significantly and independently associated with ORR of matched therapies in multivariable analysis (P = 0.017 and 0.004, respectively).

CONCLUSION

Patients with rare cancer preferentially benefited from tumor mutation profiling by increasing the chances of therapeutic response to matched therapies. Early-line treatments after profiling increase the therapeutic benefit, irrespective of tumor types.

Coffee consumption and mortality in Japan with 18 years of follow-up: the Jichi Medical School Cohort Study

OBJECTIVE

Coffee consumption can be expected to reduce mortality due to cardiovascular diseases and cancer. This study tested the hypothesis of an inverse association between coffee intake and all-cause mortality and mortality due to cancer, coronary heart disease, or stroke.

STUDY DESIGN

Prospective cohort study.

METHODS

We analyzed data from the Jichi Medical School Cohort Study, Japan, enrolling 9946 subjects (men/women: 3870/6,076, age: 19-93 years) from 12 communities. A food frequency questionnaire assessing the subjects' daily coffee consumption was used.

RESULTS

During an average follow-up of 18.4 years, the total number of deaths was 2024, including 677 for cancer, 238 for coronary heart disease, and 244 for stroke. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) of all-cause mortality and cause-specific mortality due to cancer, coronary heart disease, and stroke. Overall, no significant association was shown between coffee consumption and all-cause mortality. In the cause-specific mortality analyses, stroke mortality was significantly lower in those who consumed 1-2 cups of coffee daily (HR [95% CI]: 0.63 [0.42-0.95]) than in those who do not consume coffee, and this association occurred only in men.

CONCLUSION

This study showed no significant association between coffee consumption and all-cause mortality. A U-shaped association between coffee consumption and stroke mortality with a 37% lower stroke mortality, only significant in men who consume 1-2 cups of coffee daily was observed. It is necessary to examine the possibility of intervention studies to reduce stroke mortality through coffee consumption.

Extent of self-adjustment to AF in exercise capacity evaluates significance of sinus maintenance and determines suitability of sinus maintenance therapy in patients with persistent AF

 

Atrial fibrillation (AF) causes hemodynamic inefficiency and possibly deteriorates to heart failure (HF). However, we have experienced drastic variances in the extent of HF deterioration in persistent AF (PeAF) patients. Some studies showed that newly developed PeAF (New AF), not preexisting PeAF adversely impacted HF patients in two years. These issues suggest that most PeAF patients gradually adjust to AF-induced hemodynamic inefficiency, however the extent of self-adjustment to PeAF differs among patients. We hypothesized that the extent of the self-adjustment might determine the adverse impact of New AF on patients. We proposed that especially New AF patients with poor adjustment to PeAF should be targeted for aggressive sinus rhythm (SR) maintenance through catheter ablation (RFCA). We considered exercise capacity (EC) of PeAF patients as the extent of the self-adjustment to PeAF. Consequently, we sought to investigate whether EC testing (CPX) in PeAF patients could be used as a determinant for suitability of aggressive SR maintenance therapy in PeAF patients.

Subjects & Method: We performed CPX to evaluate Peak VO2 intake (PVO2) at baseline for 196 consecutive PeAF patients undergoing RFCA (male: 151, female: 45). After >6 months SR-maintenance, CPX was repeated. %PVO was calculated by standardizing PVO to age and gender. During RFCA, Swan-Ganz catheter study was done to monitor changes in hemodynamics before and after RFCA. Echocardiography was done at baseline, 6 months after SR maintenance.

Results

%PVO varied from 38 to 175% before RFCA. %POV2 of NYHA 3 class patients was 76.8±17.7%. PeAF patients with 80% and more of %PVO2 seemed adjusted to AF in terms of exercise capacity. In this study we defined PeAF patients below 80% PVO2 as Non-adjusted. Out of 196 patients, 149 undertook CPX again. Changes in %PVO2 ranged from −38% to 48% (median: 7.0%). According to multi-regression analysis of changes in %PVO, PeAF patients with Non-adjustment (β=0.31), greater increase in HR during repeated CPX (β=0.40), larger reduction in E/e (β=−0.21) after SR maintenance, obtained larger improvement in EC. Particularly, Non-AF adjustment in PeAF patients was the sole predictor of improvement in EC after RFCA.

Furthermore, we sought to identify the determinants of Non-AF adjustment in PeAF patients. Multivariate logistic analysis demonstrated that female patients became Non-adjusted significantly more easily than male (p<0.001). Increase in HR during CPX was the most important factor for adjustment to PeAF. In males, poor LV diastolic function, higher Pulmonary vascular resistance were also negative predictors for adjustment to PeAF. However, there is concern about deterioration in EC for patients with chronotropic incompetence revealed after RFCA.

Conclusion

The extent to which PeAF patients could adjust to AF helps in evaluating the significance of SR-maintenance and determining the suitability of aggressive SR-maintenance therapy.

Funding Acknowledgement

Type of funding source: None

P924Prognostic significance of moderate primary mitral regurgitation and atrial fibrillation

Background

Severe primary mitral regurgitation [degenerativeMR (DMR)] is associated with poor outcome, including cardiac death and admission due to worsening heart failure. Whereas little information is available regarding the characteristics of moderate DMR and their impact on prognostic outcome.

The aim of the present study was to investigate the prognosis and its determinant in patients with moderate DMR.

Methods

From 13,700 consecutive patients who underwent transthoracic echocardiography. We selected moderate DMR but without other underlying cardiac diseases. Characteristics and event free rate as compared with age- and gender-matched patients with none to mild MR.

Results

Of a total of our cohort, 185 (1%) patients had moderate DMR, and we compared with 185 age- and gender-matched patients with none to mild MR. During the follow-up period of 1372±655 days, 30 patients (8%) met the composite endpoint defined as cardiac death and admission due to worsening heart failure. Kaplan-Meier analysis showed patients with moderate DMR was significantly associated with a poor outcome compared to patients with none to mild MR (log-ranktest P<0.0001). Cox proportional hazard ratio revealed thatmoderate MR and atrial fibrillation (AF) were the independent predictors of the composite endpoint.

Prgnostic outcome: AF and moderate DMR

Conclusions

Patients withmoderate DMR and concomitant AF had a significant poor outcome. An activesurveillance and some intervention for AF and moderate MR may be required.

Effect of attention bias modification on event-related potentials in patients with irritable bowel syndrome: A preliminary brain function and psycho-behavioral study

BACKGROUND

Attention bias modification normalizes electroencephalographic abnormalities in alpha and beta power percentages related to attention in patients with irritable bowel syndrome (IBS). Yet, it is unknown whether ABM contributes to the normalization of event-related potentials (ERP) in these patients. We hypothesized that ERP related to attention deficit would be normalized after ABM implementation in individuals with IBS.

METHODS

Thirteen patients with IBS and 10 control subjects completed a 2-month intervention that included five ABM sessions. Each session included 128 trials, resulting in a total of 640 trials during the study period. Event-related potentials were measured at the first and fifth sessions. As per the international 10-20 system for electroencephalographic electrode placement, right parietal P4 was evaluated to measure the attention component of facial expression processing.

KEY RESULTS

A group comparison of P100 latency at P4 revealed that latencies were significantly different between groups in session 1 (IBS vs control, 108 ± 8 vs 97 ± 14; t = -2.51, P = .0203). This difference was absent in session 5 (94 ± 11 vs 93 ± 11, respectively; t = -0.397, P = .6954, r = .09), indicating an effect of ABM in the IBS group.

CONCLUSIONS AND INFERENCES

Attention bias modification may have clinical utility for normalizing brain function and specifically attentional abnormalities in patients with IBS.

Optimization of DARTEL Settings for the Detection of Alzheimer Disease

BACKGROUND AND PURPOSE

Although Diffeomorphic Anatomical Registration Through Exponentiated Lie Algebra (DARTEL) has been introduced as an alternative to conventional voxel-based morphometry, there are scant data available regarding the optimal image-processing settings. The aim of this study was to optimize image-processing and ROI settings for the diagnosis of Alzheimer disease using DARTEL.

MATERIALS AND METHODS

Between May 2002 and August 2014, we selected 158 patients with Alzheimer disease and 198 age-matched healthy subjects; 158 healthy subjects served as the control group against the patients with Alzheimer disease, and the remaining 40 served as the healthy data base. Structural MR images were obtained in all the participants and were processed using DARTEL-based voxel-based morphometry with a variety of settings. These included modulated or nonmodulated, nonsmoothed or smoothed settings with a 4-, 8-, 12-, 16-, or 20-mm kernel size. A z score was calculated for each ROI, and univariate and multivariate logistic regression analyses were performed to determine the optimal ROI settings for each dataset. The optimal settings were defined as those demonstrating the highest χ² test statistics in the multivariate logistic regression analyses. Finally, using the optimal settings, we obtained receiver operating characteristic curves. The models were verified using 10-fold cross-validation.

RESULTS

The optimal settings were obtained using the hippocampus and precuneus as ROIs without modulation and smoothing. The average area under the curve was 0.845 (95% confidence interval, 0.788-0.902).

CONCLUSIONS

We recommend using the precuneus and hippocampus as ROIs without modulation and smoothing for DARTEL-based voxel-based morphometry as a tool for diagnosing Alzheimer disease.

Effect of attention bias modification on brain function and anxiety in patients with irritable bowel syndrome: A preliminary electroencephalogram and psycho-behavioral study

BACKGROUND

Gastrointestinal symptoms of irritable bowel syndrome (IBS) show a reciprocal relationship with anxiety. In this intervention-based study, we investigated the utility of attention bias modification (ABM) therapy in patients with IBS. We hypothesized that IBS-related electroencephalographic abnormalities would be normalized after ABM therapy.

METHODS

Seventeen patients with IBS and 13 healthy subjects completed five ABM intervention sessions over a 2-month period. Each session included 128 ABM trials, resulting in a total of 640 trials across the intervention period. For each trial, subjects viewed a pair of facial expression images and were instructed to indicate the position of the neutral face as quickly and accurately as possible by pressing one of two buttons on a button box. Electroencephalography data (alpha and beta power percentages) were collected during the 1st and 5th sessions.

KEY RESULTS

Generalized estimating equations of relative alpha power revealed a significant effect of period was identified at O2 (P=.036). Paired t tests revealed that ABM significantly increased relative alpha power at O2 in patients with IBS. Generalized estimating equation of relative beta power revealed a significant effect of the group × period interaction was identified at Pz (P=.035). Paired t tests revealed that ABM significantly decreased relative beta power at Pz in patients with IBS.

CONCLUSIONS & INFERENCES

Attention bias modification may normalize brain function related to attention and anxiety in patients with IBS.

Serum levels of hepatocyte growth factor and epiregulin are associated with the prognosis on anti-EGFR antibody treatment in KRAS wild-type metastatic colorectal cancer

Background:

Ligands of transmembrane receptor tyrosine kinases have important roles in cell proliferation, survival, migration and differentiation in solid tumours. We conducted this study to evaluate the relationship between concentration of serum ligands and prognosis of patients with metastatic colorectal cancer (mCRC) treated with anti-epidermal growth factor receptor (EGFR) antibodies.

Methods:

Between August 2008 and August 2011, serum samples were obtained from KRAS wild-type patients who met the inclusion criteria and received an anti-EGFR antibody treatment. Serum concentration of ligands was measured by an enzyme-linked immunosorbent assay, and somatic mutations of KRAS, BRAF, PIK3CA and BRAF were analysed by direct sequencing.

Results:

A total of 103 patients were enrolled in the present study. At the pretreatment serum levels, patients with high levels of hepatocyte growth factor (HGF) had shorter progression-free survival (PFS) and overall survival (OS) compared with those with low levels of HGF (median PFS: 6.4 months vs 4.4 months; P<0.001, median OS: 15.3 months vs 8.0 months; P<0.001, respectively). Patients with high levels of epiregulin (EREG) also had shorter PFS and OS compared with those with low levels of EREG (median PFS: 6.6 months vs 4.9 months; P=0.016, median OS: 13.8 months vs 7.4 months; P=0.048, respectively). In addition, patients whose serum levels of ligands were elevated at progressive disease had shorter PFS and OS compared with other patients.

Conclusions:

Our study indicated that high levels of HGF and EREG were associated with resistance to treatment with anti-EGFR antibodies in KRAS wild-type patients with mCRC. Our findings will contribute to the newly combination therapy on the treatment of anti-EGFR antibodies.

Feasibility of endoscopic mucosal resection as salvage treatment for patients with local failure after definitive chemoradiotherapy for stage IB, II, and III esophageal squamous cell cancer

Local failure after definitive chemoradiotherapy (CRT) for stage IB, II, and III esophageal cancer is one of the causes of poor outcome. Endoscopic mucosal resection (EMR) is an effective treatment for superficial esophageal cancer. However, its feasibility as a salvage treatment for local recurrent or residual tumors after definitive CRT for stage IB, II, and III esophageal cancer remains unclear. Between January 2000 and February 2008, 274 patients with stage IB, II, and III esophageal squamous cell cancer excluding T4 received definitive CRT at the National Cancer Center Hospital, Japan. Of these patients, nine patients with local recurrence after achieving complete response and two patients with residual tumor underwent salvage EMR. The technique of salvage EMR involved a strip biopsy method. We retrospectively reviewed the 11 patients (13 lesions). Characteristics of all 11 patients were as follows: median age of 69 (range: 45-78); male/female: 10/1; baseline clinical stage (Union for International Cancer Control 7th) IB/IIA/IIB/III: 1/3/7/0. The depth of resected tumor was limited to the mucosal layer in seven lesions and submucosal in six lesions. En bloc resection was performed on six lesions (46%). The vertical margin was free of cancer cells in 11 lesions (84.6%). No major complications, such as hemorrhage requiring blood transfusion and perforation, were experienced. At a median follow-up period of 38.9 months (range: 5.3-94 months) after salvage EMR, no recurrence was detected in six patients (54%). Local recurrence was detected in five patients (27%). Of these patients, two had lung metastasis simultaneously, and one was also detected lung metastasis 2 months after the detection of local recurrence. The 5-year survival rate after salvage EMR was 41.6%. Salvage EMR is a feasible treatment option for local recurrent or residual lesions after definitive chemotherapy and/or radiotherapy for stage IB, II, and III esophageal squamous cell cancer.

Differential mechanisms underlie the regulation of serotonergic transmission in the dorsal and median raphe nuclei by mirtazapine: a dual probe microdialysis study

RATIONALE

Blockade of α2 adrenoceptors and histamine H1 receptors plays important roles in the antidepressant and hypnotic effects of mirtazapine.

OBJECTIVES

However, it remains unclear how mirtazapine's actions at these receptors interact to affect serotonergic transmission in the dorsal (DRN) and median (MRN) raphe nuclei.

METHOD

Using dual-probe microdialysis, we determined the roles of α2 and H1 receptors in the effects of mirtazapine on serotonergic transmission in the DRN and MRN and their respective projection regions, the frontal (FC) and entorhinal (EC) cortices.

RESULTS

Mirtazapine (<30 μM) failed to alter extracellular serotonin levels when perfused alone into the raphe nuclei, but when co-perfused with a 5-HT1A receptor antagonist, mirtazapine increased serotonin levels in the DRN, MRN, FC, and EC. Serotonin levels in the DRN and FC were decreased by blockade and increased by activation of H1 receptors in the DRN. Serotonin levels in the MRN and EC were not affected by H1 agonists/antagonists perfused in the MRN. The increase in serotonin levels in the DRN and FC induced by DRN H1 receptor activation was attenuated by co-perfusion with mirtazapine. Furthermore, the increase in serotonin levels (DRN/FC) induced by DRN α2 adrenoceptor blockade was attenuated by concurrent DRN H1 blockade, whereas the increase in serotonin levels (MRN/EC) induced by MRN α2 adrenoceptor inhibition was unaffected by concurrent MRN H1 receptor blockade.

CONCLUSION

These results suggest that enhanced serotonergic transmission resulting from α2 adrenoceptor blockade is offset by subsequent activation of 5-HT1A receptors and, in the DRN but not MRN, H1 receptor inhibition. These pharmacological actions of mirtazapine may explain its antidepressant and hypnotic actions.

Relationship between methylation status of PTEN and point mutation of the EGFR L2 domain and efficacy of cetuximab in metastatic colorectal cancer

458

Background: The KRAS mutation has been associated with resistance to cetuximab, an anti-epidermal growth factor receptor (EGFR) monoclonal antibody, in metastatic colorectal cancer (mCRC). However, the predictive biomarkers of cetuximab resistance in KRAS wild-type mCRC remain unknown. We explored the possible roles of PTEN methylation and mutation of the EGFR L2 domain, which is the site of binding to cetuximab, in cetuximab resistance in KRAS wild-type mCRC.

Methods: The subjects were 247 mCRC patients screened for KRAS status at the National Cancer Center Hospital between September 2008 and April 2010. Genomic DNA was extracted from formalin- fixed paraffin-embedded colorectal cancer tissue samples. Mutation analysis of KRAS and the EGFR L2 domain was performed by direct sequencing. Methylation analysis of PTEN was performed by quantitative real-time methylation-specific PCR with a set of primers specific to the methylated and unmethylated sequences, using sodium bisulfate-modified DNA.

Results: Of the 247 mCRC patients, 136 patients had wild-type KRAS (55%). In 9 of these patients, the quality of the DNA was sufficient for analysis of PTEN methylation levels. Eight of the 9 patients received a cetuximab-based regimen (with irinotecan: 4, monotherapy: 4). The best response was PR in 4 patients (25%), SD in 2 (12.5%), and PD in 2 (12.5%). The best response of the one patient with methylated PTEN treated with cetuximab and irinotecan was SD. Mutation analysis of the EGFR L2 domain was performed in 65 of the 136 patients with wild-type KRAS. All of them received a cetuximab-based regimen (with irinotecan: 50, monotherapy: 15). The best response was PR in 13 patients (20%), SD in 26 (40%), PD in 20 (31%). The one patient who had a mutation at exon 9 showed a partial response to cetuximab and irinotecan.

Conclusions: Methylation of PTEN and mutation of the EGFR L2 domain were analyzed in Japanese mCRC patients. Our findings do not provide sufficient evidence that EGFR L2 domain mutation and methylation of PTEN are correlated with resistance to cetuximab.

No significant financial relationships to disclose.

Prophylactic administration of epinephrine in oxaliplatin-related hypersensitivity reaction

610

Background: Alongside disease progression or neurotoxicity, oxaliplatin-related hypersensitivity reaction is a common reason for treatment discontinuation and remains a critical issue. It is unclear whether prophylactic administration of epinephrine to patients with this severe hypersensitivity reaction is effective and safe.

Methods: We retrospectively reviewed 839 consecutive colorectal cancer patients treated with oxaliplatin-containing regimens at our hospital between April 2005 and March 2010. The medical records of those patients who had received prophylactic epinephrine (1:1000 solution) were examined. Hypersensitivity reaction was graded according to CTCAE version 3.0.

Results: Twelve patients (8 male and 4 female; median age, 66 years) had received prophylactic epinephrine. The hypersensitivity reaction, even though the patients were receiving prophylactic corticosteroid and antihistamine drugs, was grade 0/1/2/3 = 0/0/10/2. The median number of epinephrine doses administered was 6 (range, 1 to 21). The worst grade of hypersensitivity for rechallenge with oxaliplatin under prophylactic administration of epinephrine was grade 0/1/2/3 = 4/3/4/1. Reasons for treatment discontinuation were disease progression in 10 patients and neurotoxicity in one patient. The remaining one patient developed grade 3 hypersensitivity reaction during 4 cycles of treatment under prophylactic administration of epinephrine, but the reaction subsided after additional administration of epinephrine and corticosteroid. Common adverse events with administration of epinephrine were hypertension (4 patients), palpitation (3 patients) and headache, dizziness, fatigue, and bladder pain (1 patient each).

Conclusions: Prophylactic administration of epinephrine may be effective and tolerated in patients with moderate to severe oxaliplatin-related hypersensitivity reaction.

No significant financial relationships to disclose.

Feasibility study of adjuvant chemotherapy with S-1 plus cisplatin for gastric cancer

PURPOSE

To evaluate the feasibility of S-1 plus cisplatin as adjuvant chemotherapy for stage III gastric cancer after curative resection.

METHODS

Japanese patients with stage III gastric cancer who underwent gastrectomy with D2 lymph node resection were enrolled. Treatment consisted of 3 cycles of S-1 (80 mg/m(2)/day, b.i.d.) for 21 days followed by a 14-day rest, and cisplatin (60 mg/m(2) iv) on day 8. After that, S-1 monotherapy was given on days 1-28 every 6 weeks until 1-year postsurgery. After protocol amendment, the first chemotherapy cycle consisted of S-1 monotherapy; cisplatin was added to cycles 2, 3, and 4, followed by S-1 monotherapy up to 1-year postsurgery. The primary endpoint was the completion rate of three cycles of S-1 plus cisplatin.

RESULTS

A total of 63 enrolled patients have been evaluated. Grade 3/4 toxicities included neutropenia (40%), anorexia (28%), and febrile neutropenia (4%) before protocol amendment (n = 25), and neutropenia (37%), anorexia (8%), and febrile neutropenia (3%) after amendment implementation (n = 38). Excluding ineligible cases, treatment completion rates were 57% (12/21) before and 81% (30/37) after the protocol amendment.

CONCLUSIONS

The amended S-1 plus cisplatin is more feasible than the original protocol because of early dose reduction of S-1 prior to cisplatin addition and greater recovery time from surgery prior to cisplatin. This treatment should be considered as a feasible experimental arm for the next postoperative adjuvant phase III trial.

Pleiotropic effects of mitiglinide in type 2 diabetes mellitus

This study investigated the effects of mitiglinide in 16 patients with type 2 diabetes mellitus treated with 30 mg/day mitiglinide, divided into three doses given just before each meal, for approximately 12 months. A 450 kcal meal tolerance test was performed at baseline and after 3, 6 and 12 months, and levels of plasma glucose and immunoreactive insulin were measured. Various parameters of glucose metabolism and lipid metabolism, urinary albumin and markers of atherosclerosis, coagulation and fibrinolysis were also determined. Mitiglinide showed a rapid stimulatory effect on insulin secretion and reduced the levels of plasma glucose. The free fatty acid level significantly decreased at 60 min after the meal tolerance test. Mitiglinide also significantly lowered glycosylated haemoglobin and raised 1,5-anhydroglucitol after 6 months, and significantly decreased urinary albumin after 12 months. These data indicate that mitiglinide may have beneficial effects not only on glycaemic control but also on lipid metabolism and urinary albumin excretion, and may have a role in the prevention of the vascular complications of diabetes.

Site-specific differences in central processing of visceral stimuli from the rectum and the descending colon in men

BACKGROUND

It has been reported that different brain activation areas are demonstrated during somatosensory and visceral stimulation. However, no study thus far has investigated how activated patterns in the human brain differ during visceral stimulation of different sites of the digestive tracts. The aim of this study was to determine possible site-specific differences in brain responses and perceptions during visceral stimulation of two different sites, the intraluminal distentions of the rectum and descending colon.

METHODS

Regional cerebral blood flow was assessed in 32 healthy right-handed male subjects using H(2)(15)O positron emission tomography during distention of the rectum (R group, n = 16) or descending colon (DC group, n = 16) at 40 or 20 mmHg.

KEY RESULTS

R group reported significantly higher scores of abdominal pain (P < 0.05) and urge to defecate (P < 0.001) during the application of stimulus at 40 mmHg compared with DC group but not of abdominal bloating or anxiety. In comparisons of response to the 40-mmHg stimulus, R group showed significantly greater activation in posterior midcingulate cortex (MCC) and right anterior and posterior insula, whereas DC group showed greater activation in subgenual anterior cingulate cortex (ACC), perigenual ACC and left orbitofrontal and superior temporal cortices.

CONCLUSIONS & INFERENCES

These findings suggest that central projections of painful visceral stimulation from the rectum and descending colon differ in affective, cognitive and nociceptive processing in the brain, which may result in different perceptions of visceral stimulation from different sites.