Forced expression of miR-143 and -145 in cardiomyocytes induces cardiomyopathy with a reductive redox shift

BACKGROUND

Animal model studies show that reductive stress is involved in cardiomyopathy and myopathy, but the exact physiological relevance remains unknown. In addition, the microRNAs miR-143 and miR-145 have been shown to be upregulated in cardiac diseases, but the underlying mechanisms associated with these regulators have yet to be explored.

METHODS

We developed transgenic mouse lines expressing exogenous miR-143 and miR-145 under the control of the alpha-myosin heavy chain (αMHC) promoter/enhancer.

RESULTS

The two transgenic lines showed dilated cardiomyopathy-like characteristics and early lethality with markedly increased expression of miR-143. The expression of hexokinase 2 (HK2), a cardioprotective gene that is a target of miR-143, was strongly suppressed in the transgenic hearts, but the in vitro HK activity and adenosine triphosphate (ATP) content were comparable to those observed in wild-type mice. In addition, transgenic complementation of HK2 expression did not reduce mortality rates. Although HK2 is crucial for the pentose phosphate pathway (PPP) and glycolysis, the ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG) was unexpectedly higher in the hearts of transgenic mice. The expression of gamma-glutamylcysteine synthetase heavy subunit (γ-GCSc) and the in vitro activity of glutathione reductase (GR) were also higher, suggesting that the recycling of GSH and its de novo biosynthesis were augmented in transgenic hearts. Furthermore, the expression levels of glucose-6-phosphate dehydrogenase (G6PD, a rate-limiting enzyme for the PPP) and p62/SQSTM1 (a potent inducer of glycolysis and glutathione production) were elevated, while p62/SQSTM1 was upregulated at the mRNA level rather than as a result of autophagy inhibition. Consistent with this observation, nuclear factor erythroid-2 related factor 2 (Nrf2), Jun N-terminal kinase (JNK) and inositol-requiring enzyme 1 alpha (IRE1α) were activated, all of which are known to induce p62/SQSTM1 expression.

CONCLUSIONS

Overexpression of miR-143 and miR-145 leads to a unique dilated cardiomyopathy phenotype with a reductive redox shift despite marked downregulation of HK2 expression. Reductive stress may be involved in a wider range of cardiomyopathies than previously thought.

Providing Weight Loss Support to Patients Who Are Obese in Preparation for Colorectal Cancer Surgery to Reduce Surgical Site Infection Risk: A Mixed-methods Study

Obesity increases the risk of surgical site infections (SSIs) after colorectal cancer surgery, but strategies to support weight loss in obese patients who have colorectal cancer have not been established.

PURPOSE

This mixed-methods study, using retrospective and prospective data, aimed to explore inhibitors and facilitators of preoperative weight loss in obese patients with colorectal cancer and the potential impact of preoperative weight loss support on SSIs.

METHODS

Patients with a body mass index (BMI) of ≥ 25 kg/m2 were eligible to participate in the weight loss support program. Patient demographic, history, surgical, and outcomes variables were abstracted from the records. Five (5) nurses who provided weight loss support participated in a focus group interview method to explore weight loss inhibitory and promotional factors. Descriptive statistics and qualitative analysis methods were used to examine the data.

RESULTS

Twenty-six (26) patients participated in the program for a mean of 45.5 days (SD ± 25.3). Body weight decreased from 79.8 kg (SD ± 15.6) to 75.7 kg (SD ± 14.3), and BMI decreased from 30.4 kg/m² (SD ± 4.7) to 29.4 kg/m² (SD ± 5.0) (P < .05). The average weight loss percentage was 4.9% (SD ± 3.4). In 14 patients, the weight loss percentage was 5% or more. SSIs occurred in 5 of 26 patients (19.2%). Additionally, 4 of 26 patients (15.4%) who had 8.8% or more weight loss did not manifest SSIs. Previous weight loss before the preoperative surgery visits, lack of motivation for weight loss, and time and duration required for weight loss were identified as inhibitory factors, whereas history of successful weight loss experience, knowledge acquisition, family support, and reduced knee and lower back pain were identified as promotional factors for weight loss.

CONCLUSION

Patients in this program lost weight prior to colorectal surgery. Research to further explore the safety and effects of preoperative weight loss in obese patients with colorectal cancer as well as inhibitory and promotional factors for participation and success is needed.

Vaticanol C, a phytoalexin, induces apoptosis of leukemia and cancer cells by modulating expression of multiple sphingolipid metabolic enzymes

Resveratrol (RSV) has recently attracted keen interest because of its pleiotropic effects. It exerts a wide range of health-promoting effects. In addition to health-promoting effects, RSV possesses anti-carcinogenic activity. However, a non-physiological concentration is needed to achieve an anti-cancer effect, and its in vivo bioavailability is low. Therefore, the clinical application of phytochemicals requires alternative candidates that induce the desired effects at a lower concentration and with increased bioavailability. We previously reported a low IC₅₀ of vaticanol C (VTC), an RSV tetramer, among 12 RSV derivatives (Ito T. et al, 2003). However, the precise mechanism involved remains to be determined. Here, we screened an in-house chemical library bearing RSV building blocks ranging from dimers to octamers for cytotoxic effects in several leukemia and cancer cell lines and their anti-cancer drug-resistant sublines. Among the compounds, VTC exhibited the highest cytotoxicity, which was partially inhibited by a caspase 3 inhibitor, Z-VAD-FMK. VTC decreased the expression of sphingosine kinase 1, sphingosine kinase 2 and glucosylceramide synthase by transcriptional or post-transcriptional mechanisms, and increased cellular ceramides/dihydroceramides and decreased sphingosine 1-phosphate (S1P). VTC-induced sphingolipid rheostat modulation (the ratio of ceramide/S1P) is thought to be involved in cellular apoptosis. Indeed, exogenous S1P addition modulated VTC cytotoxicity significantly. A combination of SPHK1, SPHK2, and GCS chemical inhibitors induced sphingolipid rheostat modulation, cell growth suppression, and cytotoxicity similar to that of VTC. These results suggest the involvement of sphingolipid metabolism in VTC-induced cytotoxicity, and indicate VTC is a promising prototype for translational research.

Risk factors for parastomal hernia of loop stoma and relationships with other stoma complications in laparoscopic surgery era

Background

Laparoscopic approach is now a widespread technique used worldwide, but there are few recent studies on risk factors for parastomal hernia. Therefore, this study was performed to analyze the incidence of parastomal hernia in laparoscopic and open surgery in which a loop stoma was created and was intended to be temporary, and to determine risk factors for parastomal hernia formation. Associations between parastomal hernia and other stoma-related complications were also analyzed.

Methods

A retrospective analysis of patient and surgical characteristics was performed in 153 consecutive patients who underwent a temporary diverting loop ileostomy or colostomy after surgery related to malignant diseases at our hospital from January to December 2016.

Results

Parastomal hernia developed in 77 cases (50.3%), including 39 (25.5%) diagnosed by physical examination and 38 (24.8%) detected by CT alone. On multivariate analysis, a stoma not passing through the middle of the rectus abdominis muscle was the only independent risk factor for parastomal hernia formation (p = 0.005) during the median follow-up of 245.0 days. When we analyzed the factors that were associated with a stoma not passing through the middle of the rectus abdominis muscle, the only independent factor associated with this misplacement of the stoma was a laparoscopic approach (p = 0.012). An analysis of stoma-related complications showed that peristomal skin disorders were significantly associated with parastomal hernia (p = 0.049).

Conclusions

This study showed that a stoma that is not formed through the middle of the rectus abdominis muscle is a risk factor for parastomal hernia formation, and that a laparoscopic approach is associated with this risk factor. Moreover, parastomal hernia is significantly associated with peristomal skin disorders.

A case of resected retroperitoneal metachronous solitary metastasis from caecal cancer

Colorectal cancer metastasis to the retroperitoneum, especially solitary metastasis allowing curative resection, is rare. We report a case of complete resection of retroperitoneal metachronous solitary metastasis from caecal cancer without distant metastasis. An 80-year-old woman with caecal cancer underwent laparoscopic ileocaecal resection with regional lymph node dissection. According to the eighth edition of the TNM classification, the pathological diagnosis was stage IIA (T3N0M0). Six months following the surgery, computed tomography revealed a solitary mass of 2cm diameter, dorsal to the right kidney. A second procedure for the removal of the tumour was performed. The lesion was pathologically diagnosed as a metachronous solitary retroperitoneal metastasis from caecal cancer. The patient is surviving and free from recurrence 17 months following the second procedure.

Involvement of MCL1, c-myc, and cyclin D2 protein degradation in ponatinib-induced cytotoxicity against T315I(+) Ph+leukemia cells

T315I mutation found in chronic myelogenous leukemia (CML) and Ph + ALL patients is the most serious one among resistance against BCR/ABL kinase inhibitors including imatinib and is only responsive to ponatinib (PNT). However, the novel strategy is required to reduce life-threatening adverse effects of PNT including ischemic cardiovascular disease. We examined the mechanism of PNT-induced cytotoxicity against a T315I(+) Ph + ALL cell line, TccY/Sr. PNT induced apoptosis (increased sub G1 cells, and cleaved caspase3 and PARP), and suppressed protein expression of MCL1, cyclin D2 and c-myc, which were reversed by a proteasome inhibitor, MG132, suggesting enhanced proteasomal degradation by PNT. Among BCL2 family inhibitors, MCL1 inhibitors (maritoclax and AZD5991) robustly induced cell death, showing the MCL1-dependent survival of TccY/Sr cells. Decreased MCL1 and c-myc expression by PNT was also observed in T315I(+) MEGA2/STIR cells. PNT suppressed PI3K activation followed by AKT inhibition and GSK3 dephosphorylation. PI3K/AKT inhibitors mimicked PNT, suggesting that PI3K/AKT signaling is important for survival of TccY/Sr cells. Moreover, GSK3 inhibitor (SB216763) reduced PNT-induced cytotoxicity and degradation of c-myc and MCL1. AZD5991 exhibited the synergistic action with PNT, anti-cancer drugs and venetoclax (BCL2 inhibitor), suggesting the utility of MCL1 inhibitor alone or in combination as a future clinical option for Ph + leukemia patients.

Impact of intraoperative indocyanine green fluorescence angiography on anastomotic leakage after laparoscopic sphincter-sparing surgery for malignant rectal tumors

PURPOSE

Whether indocyanine green fluorescence angiography (ICG-FA) during rectal surgery is effective in reducing anastomotic leakage remains unclear. This study aimed to investigate the effect of intraoperative ICG-FA on anastomotic leakage after sphincter-sparing surgery for malignant rectal tumors.

METHODS

This was a retrospective, single-center cohort study conducted on 852 consecutive patients who underwent laparoscopic sphincter-sparing surgery from January 2007 to June 2017 at our institution. The incidence of anastomotic leakage was compared between patients who underwent ICG-FA to determine the proximal resection margin and those in whom this technique was not performed, using logistic regression analysis, including propensity score.

RESULTS

A total of eight patients were excluded (one patient with previous low anterior resection and seven patients who underwent simultaneous resection for other primary cancers), resulting in 844 patients being analyzed. Before propensity score matching, 141 patients (16.7%) who underwent ICG-FA were compared with 703 patients (83.3%) in whom ICG-FA was not performed. The incidence of anastomotic leakage was 2.8% (4/141) in the ICG-FA group and 12.4% (87/703) in the control group (p = 0.001). After propensity score matching (n = 420), the patient characteristics between the two groups were well balanced, and the incidence of anastomotic leakage was 2.8% (4/141) in the ICG-FA group and 13.6% (38/279) in the control group (p = 0.001). Logistic regression analyses using propensity score showed that patients who underwent ICG-FA had significantly lower odds of anastomotic leakage.

CONCLUSION

Intraoperative ICG-FA is a promising method to reduce anastomotic leakage after laparoscopic rectal surgery.

Prognostic Impact of Curative Resection for Peritoneal Recurrence of Colorectal Cancer

BACKGROUND

Peritoneal recurrence (PR) of colorectal cancer is a poor prognostic factor but may be treatable by curative resection. We investigated the efficacy of this treatment and identified risk factors for postoperative recurrence.

METHODS

The subjects were patients who underwent radical surgery for colorectal cancer between January 2006 and March 2014. Those with PR were retrospectively reviewed. Prognostic factors for overall survival (OS) and risk factors for postoperative recurrence were identified.

RESULTS

Among 2256 patients, 66 had PR (2.9%). Surgical resection of PR was performed in 41 patients. Curative resection was achieved macroscopically in 38 cases without diffuse metastases in the peritoneum distant from the primary tumor and with a peritoneal cancer index < 10. In multivariate analysis, curative resection was a significant prognostic factor [hazard ratio (HR) 0.198] for better 5-year OS compared with cases without curative resection (68.7% vs. 6.3%, P < 0.001). In 28 cases with concurrent metastasis, curative resection significantly improved 5-year OS compared with no curative resection (78.7% vs. 0%, P = 0.008). In the 38 patients with curative resection, the 3-year recurrence-free survival rate was 21.4%. In multivariate analysis, concurrent metastasis was a significant risk factor [HR 3.394] for postoperative recurrence, and cases with concurrent metastasis more frequently had recurrence within 2 years after curative resection.

CONCLUSIONS

Curative resection improved the prognosis in patients with limited and resectable PR of colorectal cancer with or without concurrent metastasis. However, recurrence after curative resection was common and concurrent metastasis was a risk factor for this recurrence.

VOLTAGE-B study: Nivolumab monotherapy and subsequent curative surgery following preoperative chemoradiotherapy in patients with locally recurrent rectal cancer (LRRC) without previous radiotherapy

100

Background: Chemoradiotherapy (CRT) followed by curative resection in patients (pts) with local recurrence after radical surgery for primary rectal cancer is the preferred strategy if radiotherapy (RT) was not previously performed. In VOLTAGE-A study, nivolumab plus surgery following CRT showed a promising pathologic complete response (pCR) rate of 30% in pts with microsatellite-stable (MSS) advanced primary rectal cancer. The treatment sequence was prospectively investigated in pts with Locally Recurrent Rectal Cancer (LRRC) in VOLTAGE-B. Methods: Pts with pelvic LRRC without previous RT were included. Five cycles of nivolumab (240 mg q2 weeks) plus curative surgery following CRT (50.4 Gy with capecitabine 1,650 mg/m2) were performed. The pCR rate using AJCC tumor regression grading and curative resection rate were key endpoints. Planned sample size in VOLTAGE-B was set 10 pts in an exploratory manner. Results: From May to Oct 2018, 10 pts were included. Median age was 65 and 8 were male. Curative resection was performed in nine pts with MSS. One had a newly diagnosed supraclavicular lymph node metastasis before surgery. As one pt with AJCC grade 0, seven with grade 2, and one with grade 3, were observed, pCR rate was 10%. As of cut-off date of Apr 2019, three pts showing recurrence out of the nine pts were observed. Nivolumab-related adverse events (AEs) were only one pt with grade 1 hyperthyroidism and one with grade 1 erythema. Grade 3/4 surgery-related AEs were observed in six pts, including two pts with ileus and two with pelvic infections. No treatment-related deaths were observed. Conclusions: The pCR rate of 10% with acceptable toxicity was shown in MSS LRRC pts treated with nivolumab plus curative surgery following CRT. Translational research exploring better predictors of efficacies of study treatment are ongoing. Clinical trial information: NCT02948348.

Ki67 expression and localization of T cells after neoadjuvant therapies as reliable predictive markers in rectal cancer

Chemoradiotherapy (CRT) is the standard neoadjuvant therapy for locally advanced rectal cancer (RC). However, neoadjuvant chemotherapy (NAC) also shows favorable outcomes. Although the immunological environment of RC has been thoroughly discussed, the effect of NAC on it is less clear. Here, we investigated the immunological microenvironment, including T cell infiltration, activation, and topological distribution, of resected RC tissue after neoadjuvant therapies and evaluated the correlation between T cell subsets and patient prognosis. Rectal cancer patients (n = 188) were enrolled and categorized into 3 groups, namely CRT (n = 41), NAC (n = 46), and control (surgery alone; n = 101) groups. Characterization of residual carcinoma cells and T cell subsets in resected tissues was performed using multiplex fluorescence immunohistochemistry. The densities of total and activated (Ki67^high) T cells in tissues after NAC, but not CRT, were higher than in control. In both CRT and NAC groups, patients presenting with higher treatment effects showed aggressive infiltration of T cell subsets into carcinomas. Multivariate analyses of pathological and immunological features and prognosis revealed that carcinoma Ki67^highCD4⁺ T cells after CRT and stromal Ki67^highCD8⁺ T cells after NAC are important prognostic factors, respectively. Our results suggest that evaluation of T cell activation with Ki67 expression and its tumor localization can be used to determine the prognosis of advanced RC after neoadjuvant therapies.

Recurrence of rectal anastomotic leakage following stoma closure: assessment of risk factors

AIM

In patients with a previous history of rectal anastomotic leakage (AL), the surgical indications and timing for closure of a diverting stoma have to be carefully judged. Even if AL has apparently healed before stoma closure, re-leakage may occur after closure. The aim of this study was to determine the incidence and risk factors for recurrent AL following stoma closure. We also examined the treatment strategies aiming to minimize the risk of recurrent AL.

METHODS

From January 2009 to December 2016, 1008 patients underwent sphincter-saving surgery [low anterior resection, all-sphincter-preserving rectal resection with hand-sewn coloanal anastomosis (CAA) and intersphincteric resection (ISR)] for primary rectal cancer with curative intent at our hospital. A total of 69 patients with AL with a Clavien-Dindo Grade III or more who subsequently underwent closure of a diverting stoma were retrospectively reviewed for this study.

RESULTS

The incidence of recurrent leakage after stoma closure in this series was 13% overall with an incidence of 25% in the CAA/ISR group and 5% in the low anterior resection group. Significant risk factors included hand-sewn anastomosis (P = 0.0257) compared to stapled anastomosis, ischaemia at the anastomotic site as the cause of initial AL (P < 0.001) and a shorter interval between confirmation of healing and stoma closure (P = 0.00952).

CONCLUSION

Ischaemia at the anastomotic site was the main risk factor for recurrent leakage, particularly after CAA/ISR. Additional treatment options before stoma closure should be considered to avoid re-leakage in such cases.

Genome-wide association study and whole-genome sequencing identify a deletion in LRIT3 associated with canine congenital stationary night blindness

Congenital stationary night blindness (CSNB), in the complete form, is caused by dysfunctions in ON-bipolar cells (ON-BCs) which are secondary neurons of the retina. We describe the first disease causative variant associated with CSNB in the dog. A genome-wide association study using 12 cases and 11 controls from a research colony determined a 4.6 Mb locus on canine chromosome 32. Subsequent whole-genome sequencing identified a 1 bp deletion in LRIT3 segregating with CSNB. The canine mutant LRIT3 gives rise to a truncated protein with unaltered subcellular expression in vitro. Genetic variants in LRIT3 have been associated with CSNB in patients although there is limited evidence regarding its apparently critical function in the mGluR6 pathway in ON-BCs. We determine that in the canine CSNB retina, the mutant LRIT3 is correctly localized to the region correlating with the ON-BC dendritic tips, albeit with reduced immunolabelling. The LRIT3-CSNB canine model has direct translational potential enabling studies to help understand the CSNB pathogenesis as well as to develop new therapies targeting the secondary neurons of the retina.

Long-Term Outcomes and Lymph Node Metastasis in Patients Receiving Radical Surgery for Pathological T1 Lower Rectal Cancer

BACKGROUND

Few reports have evaluated the long-term outcomes of pathological T1 (pT1) lower rectal cancer (LRC), perhaps because pT1 LRC is classified as TNM stage I if lymph node metastasis (LNM) is absent and stage IIIA if LNM is present. Moreover, it is difficult to diagnose regional LNM preoperatively. This study aimed to clarify the long-term outcomes of radical surgery for pT1 LRC and risk factor(s) for LNM. Additionally, we examined whether preoperative computed tomography (CT) and magnetic resonance imaging (MRI) findings were predictive of LNM in pT1 LRC.

METHODS

This was a retrospective analysis of the clinical characteristics, short-term operative outcomes, and long-term survival rates of 155 patients who received radical surgery and were diagnosed with pT1 LRC at our hospital between January 1993 and February 2017.

RESULTS

Among patients with pT1 LRC, 5-year recurrence-free and overall survival rates were 94.0% and 95.8%, respectively. LNM status was not associated with statistically significant differences in recurrence-free or overall survival. Even in patients with LNM, the recurrence rate was only 9%. Among patients who lacked visible mesorectal lymph nodes on preoperative CT and MRI, LNM rates were 3.5% and 4.3%, respectively.

CONCLUSION

The long-term outcomes after radical surgery for pT1 LRC are satisfactory or good, regardless of the presence or absence of LNM. In patients with pT1 LRC, the absence of visible mesorectal lymph nodes on preoperative CT and MRI is associated with a reduced likelihood of LNM and has a high negative predictive value for LNM.

Resection of the urinary bladder for locally advanced colorectal cancer: a retrospective comparison of partial versus total cystectomy

Background

The postoperative and survival outcomes of patients with primary advanced colorectal cancer who undergo partial versus total cystectomy have not been adequately compared, as studies of this topic are rare and comprise relatively small cohorts. This study aimed to investigate the short- and long-term outcomes of patients who underwent en bloc partial or total cystectomy for primary advanced colorectal cancer that was suspected of adhering to or invading the urinary bladder.

Methods

The study included 90 patients who underwent various degrees of cystectomy between 1993 and 2013 to treat locally advanced primary colorectal cancer that was suspected of involving the urinary bladder. Patients in whom total cystectomy was performed solely because of prostate-invading lower rectal cancer were excluded. Data on patient characteristics and their short- and long-term outcomes were collected retrospectively to evaluate differences between partial cystectomy (the P group; n = 72) and total cystectomy (the T group; n = 18). Postoperative and oncologic outcomes were also analyzed.

Results

The T group had significantly greater operating times than the P group (median, 572 vs. 346 min); blood loss volume was also greater in the T group (median, 3092 vs. 1112 mL). The postoperative overall complication rate was significantly greater in the T group than in the P group (94.4% vs. 51.4%). With a median follow-up duration of 62 months, local recurrences were observed in 22.2 and 6.9% of patients in the T and P groups, respectively. On multivariate Cox regression analyses using partial cystectomy as the reference, total cystectomy was independently associated with poorer local recurrence-free survival (hazard ratio [HR], 4.0 95% confidence interval [CI], 1.1–15.0), relapse-free survival (HR, 2.9; 95% CI, 1.2–6.9), and overall survival (HR, 2.1; 95% CI, 1.0–4.3).

Conclusions

Patients who undergo en bloc total cystectomy for locally advanced colorectal cancers have worse postoperative and oncologic outcomes than those who undergo partial cystectomy.

Voltage: Investigator-initiated clinical trial of nivolumab monotherapy and subsequent radical surgery following preoperative chemoradiotherapy in patients with microsatellite stable locally advanced rectal cancer

3606

Background: Chemoradiotherapy (CRT) with surgery (S) is standard for patients (pts) with locally-advanced rectal cancer (LARC), and nivolumab (nivo) is active in microsatellite instability-high (MSI-H) metastatic colorectal cancer (mCRC). We studied nivo and radical S following CRT (50.4 Gy with capecitabine 1,650 mg/m2) in T3–4 NanyM0 LARC. Methods: Phase I included testing of a recommended phase II dosing schedule (RP2S). Efficacy and safety were studied in phase II pts and those given RP2S in phase I. In Cohort A-1, for microsatellite stable (MSS) LARC pts, the primary endpoint was centrally confirmed pathologic complete response (pCR) rate using AJCC tumor regression grading. The estimated required sample size assuming null and alternative hypotheses pCR = 10% and 30% was 37 pts, with a 1-sided alpha of 5% and power of 90%. Cohort A-2 was exploratory and included a maximum of 5 MSI-H pts. Results: Nivo 240 mg q2 weeks x 5 cycles, following CRT but pre-S, was the RP2S. From 1/17 to 6/18, 37 pts were enrolled in Cohort A-1. Eleven pts (30%; 90% CI 18-44%) showed pCR (AJCC grade (gr) 0). Including the 3 pts (8%) graded AJCC 1, 14 (38%) had major pathologic responses. In addition, clinical CR was observed in 1 pt (3%) refusing S after nivo. Both MSI-H LARC Cohort A-2 pts showed pCRs. Immune-related severe adverse events were observed in 2 pts (gr 3 myasthenia and gr 2 interstitial nephritis); both fully recovered and had S. No treatment-related deaths were observed. pCR rates of 60% (6/10) and 19% (5/27) (p = 0.038, Fisher exact test) were seen in pts with tumor cells with PD-L1 ≥1% and < 1% IHC staining, respectively, performed on biopsy samples taken pre-CRT. Rates of 62% (8/13) and 10% (1/10) (p = 0.029) were seen in 23 pts with samples analyzable by flow cytometry, according to CD8+ lymphocyte /regulatory T cell (CD8/Treg) ratios ≥2 and < 2, respectively. Conclusions: A promising pCR rate of 30%, with mild toxicity, was shown in MSS LARC pts treated with nivo plus radical S. PD-L1 expression and elevated CD8/Treg ratio may be better predictors of nivo benefit, warranting further study in a larger cohort. Clinical trial information: NCT02948348.

Clinical benefit of high resolution anorectal manometry for the evaluation of anal function after intersphincteric resection

AIM

Intersphincteric resection (ISR) is an advanced anus-preserving operation for treating low rectal cancer while avoiding colostomy. High-resolution anorectal manometry (HR-ARM) allows objective and accurate evaluation of anal function. However, correlations between anal function after ISR and HR-ARM parameters are unknown. The aim of the study was to evaluate HR-ARM for objective evaluation of anal function after ISR.

METHOD

A total of 81 patients who underwent ISR at our hospital between October 2014 and March 2016 were identified from our prospectively collected database and electronic medical records. Of these, 68 patients who had been evaluated using HR-ARM both before and after ISR were included in the study. Faecal incontinence (FI) was assessed by Wexner score. Multivariate analysis was performed to determine risk factors for severe FI after ISR.

RESULTS

Maximum resting pressure (MRP) (P < 0.001) and maximum squeeze pressure (P = 0.04) were significantly lower after ISR, and MRP (P < 0.001) and maximum squeeze pressure (P = 0.02) were significantly lower after total (or subtotal) ISR than after partial ISR. The overall incidence of severe FI after ISR was 18% (12/68), and a high pressure zone before ISR ≤ 3 cm (P = 0.007) and MRP before ISR > 60 mmHg (P = 0.02) were independently associated with an elevated incidence of severe FI after ISR. Decreased preoperative MRP also correlated with severe FI after ISR (P = 0.008).

CONCLUSION

HR-ARM is reliable for the evaluation of anal function after ISR, and the high pressure zone and MRP may be useful preoperative predictors of severe FI after ISR.

Effect of preoperative chemotherapy on distal spread of low rectal cancer located close to the anus

PURPOSE

This study aimed to clarify the frequency of distal spread and the optimal distal margin after preoperative chemotherapy for advanced low rectal cancer.

METHODS

The study included patients with advanced lower rectal cancer who received preoperative chemotherapy and underwent surgery during 2012-2015. We investigated the distal spread of tumor cells, defined as the distal distance from the intramucosal distal tumor edge to the farthest tumor cells located under the submucosal layer. Clinical characteristics were compared for distal spreads ≥ 10 and < 10 mm, and risk factors for distal spread ≥ 10 mm were investigated.

RESULTS

Of the 71 patients, 42 (59%) showed distal spread. Distal spreads of 1-9, 10-19, and ≥ 20 mm were observed in 27 (38%), 11 (15%), and 4 (6%) patients, respectively. Multivariate analysis revealed two independent risk factors for distal spread ≥ 10 mm after preoperative chemotherapy. The first risk factor is the presence of different therapeutic effects between the mucosal and deeper layers (meaning that superficial tumor shrinkage was evident on colonoscopy, but little tumor shrinkage was evident on magnetic resonance imaging) (odds ratio, 11.6; 95% CI, 2.22-61.3). The second risk factor is poorly differentiated or mucinous adenocarcinoma (odds ratio, 8.86; 95% CI, 1.58-49.9).

CONCLUSION

A distal margin of 20 mm is required (10 mm is insufficient) for advanced lower rectal cancer patients who receive preoperative chemotherapy followed by surgery. Independent risk factors for distal spread ≥ 10 mm include (1) the presence of different therapeutic effects between mucosal and deeper layers and (2) poorly differentiated or mucinous adenocarcinomas.

A new method for evaluating joint position sense using oral instructions based on body schema

[Purpose] This study investigated the efficacy of our independently developed method for measuring shoulder joint position sense using oral instructions based on body schema ("schema method") and investigated age-related changes. [Participants and Methods] Forty university students, 19 elderly individuals, and 16 elementary school students were included. Active shoulder abduction was measured in an upright sitting position. Target angles for position sense measurement were 45° of abduction (Target 45) and 90° of abduction (Target 90). The schema method consisted of indicating the target angles through oral instructions alone. The reproduction method and the imitation method were also used to measure angles. Abduction angle, absolute error, and variable error were calculated. [Results] A significant difference in abduction angle at Target 45 was observed between the schema method and the reproduction and imitation methods; no significant differences were observed at Target 90. No significant differences in variable error at Target 90 were observed among the three measurement methods. A significant difference in abduction angle was observed between university students and elderly individuals, and a significant difference in variable error was observed between elementary school students and elderly individuals. [Conclusion] Our body schema-based oral instruction method will be useful for evaluating joint position sense or proprioception.

Preventive effect of diverting stoma on anastomotic leakage after laparoscopic low anterior resection with double stapling technique reconstruction applied based on risk stratification

INTRODUCTION

During laparoscopic low anterior resection with double stapling technique reconstruction, it is necessary to securely implement rectal transection and anastomosis to prevent anastomotic leakage (AL). However, risk factors and preventive measures for AL are not known sufficiently. Therefore, this study aimed to elucidate risk factors associated with AL and to clarify strategies to prevent it.

METHODS

We analyzed a total of 296 cases with rectal cancer who had undergone laparoscopic low anterior resection with double stapling technique reconstruction at the National Cancer Center Hospital East. The relationship between AL and patient, tumor, and treatment characteristics were retrospectively investigated.

RESULTS

There were 186 male and 110 female patients with a median age of 62. Overall, AL occurred in 24 cases (8.1%). Being a man, having an anal verge distance ≤7 cm, and undergoing neoadjuvant chemotherapy were associated with an elevated risk for AL (P = 0.0005, 0.0034, and 0.0222, respectively). Neither an anal drainage tube nor diverting stoma creation correlated with incidence of AL. Multivariate analysis demonstrated that being a man (odds ratio = 18.0; 95% confidence interval: 2.4-138) and having an anal verge distance ≤7 cm (odds ratio = 3.8; 95% confidence interval: 1.5-9.4) were significant risk factors. These two factors were present in 61 cases, including 14 who developed AL (23.0%). In this high-risk group, diverting stoma creation significantly reduced the occurrence of AL (P = 0.0363), but an anal drainage tube had no effect on incidence of AL (P = 0.3399).

CONCLUSION

We identified the high-risk population for AL after laparoscopic low anterior resection with double stapling technique reconstruction based on two factors. This will enable surgeons to appropriately recommend diverting stoma creation.

A Rare Complication After Laparoscopic Lateral Lymph Node Dissection for Rectal Cancer: Two Case Reports of Internal Hernia Below the Superior Vesical Artery

Total mesorectal excision or mesorectal excision with lateral lymph node dissection (LLND) is a standard treatment for locally advanced lower rectal cancer in Japan. Although laparoscopic LLND for rectal cancer is technically complex and challenging, previous studies have demonstrated its feasibility, and the procedure is gradually becoming more common. With this increased use, the incidence of new complications specific to laparoscopic LLND is likely to increase, and a greater awareness of these complications is required. Here we report two cases of internal hernia of the small bowel through an orifice of the vesicohypogastric fascia below the superior vesical artery after laparoscopic LLND. There are six previous reports of internal hernia underneath the pelvic blood vessel after pelvic lymph node dissection for urological or gynecological malignancies, but our cases are the first two that occurred after LLND for rectal cancer. Almost all cases, including our two cases, occurred after laparoscopic surgery and required resection of an incarcerated small bowel. Therefore, the incidence of this complication is likely to increase as the number of cases treated with laparoscopic LLND increases. Our cases show that it is important to perform an emergency operation promptly instead of conservative treatment.

A standing posture support device that reduces laparoscopic surgeons' occupational lower limb stress

BACKGROUND

We developed a surgical knee rest (SKR) that can be used to decrease the stress placed on the lower half of the body when surgeons work in the standing position. We tested the effectiveness of this device in the context of laparoscopic surgery.

MATERIAL AND METHODS

Five healthy, right-handed male surgeons participated, and we recorded surface electromyography (sEMG) signals from the two heads of the left and right gastrocnemius (Gc) muscles during laparoscopic resections of colorectal cancer. The outcome variable was the percentage of maximum Gc muscle effort generated, reported as percent maximal isometric voluntary contraction (%MVC), and this variable was compared between surgeries performed with and without use of the SKR. Assessment covered the first 100 min of surgery, subdivided into two 50-min periods.

RESULTS

Mean %MVC of the left Gc muscle for the full 100-min test period was significantly decreased when the SKR was used (p = .027, vs. SKR not used). Notably, mean %MVC of both Gc muscles was significantly decreased during the first 50 min of surgery (p = .008 and p = .0046).

CONCLUSION

The SKR is useful for decreasing physical stress incurred by laparoscopic surgeons when working in the standing position.