Novel Measurement of the Neutron Magnetic Form Factor from A=3 Mirror Nuclei

The electromagnetic form factors of the proton and neutron encode information on the spatial structure of their charge and magnetization distributions. While measurements of the proton are relatively straightforward, the lack of a free neutron target makes measurements of the neutron's electromagnetic structure more challenging and more sensitive to experimental or model-dependent uncertainties. Various experiments have attempted to extract the neutron form factors from scattering from the neutron in deuterium, with different techniques providing different, and sometimes large, systematic uncertainties. We present results from a novel measurement of the neutron magnetic form factor using quasielastic scattering from the mirror nuclei ^{3}H and ^{3}He, where the nuclear effects are larger than for deuterium but expected to largely cancel in the cross-section ratios. We extracted values of the neutron magnetic form factor for low-to-modest momentum transfer, 0.6 Collapse

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The benefits of interval appendectomy and risk factors for nonoperative management failure in the therapeutic strategy for complicated appendicitis

PURPOSE

Emergency surgery (ES) for complicated appendicitis (CA) is associated with high morbidity. Interval appendectomy (IA) decreases this rate; however, nonoperative management (NOM) is not always successful. Some patients require unplanned ES due to NOM failure (IA failure: IA-F). This study aimed to verify the benefits of IA and to evaluate the risk factors for NOM failure.

METHODS

Patients diagnosed with CA who underwent surgery between January 2012 and December 2021 were included in this study. We compared the surgical outcomes of the ES group with those of the IA success (IA-S) and IA-F groups. We also analyzed 14 factors that predicted NOM failure.

RESULTS

Among 302 patients, the rate of severe complications (Clavien-Dindo grade ≥ III) was significantly higher in the ES group (N = 165) than in the IA-S group (N = 102). The rates were equal between the ES (N = 165) and IA-F (N = 35) groups. NOM was successful in 110 patients and failed in 27. Lack of abscesses, comorbidities, high WBC count, and free air were independent risk factors for NOM failure.

CONCLUSIONS

Considering the benefits of IA and the non-inferior surgical outcomes of IA-F compared to ES, IA is a good therapeutic strategy for CA. However, in patients exhibiting four independent risk factors for NOM failure, careful monitoring of unplanned ES is necessary.

Pks-positive Escherichia coli in tumor tissue and surrounding normal mucosal tissue of colorectal cancer patients

A significant association exists between the gut microbiome and colorectal carcinogenesis, as well as cancer progression. It has been reported that Escherichia coli (E. coli) containing polyketide synthetase (pks) island contribute to colorectal carcinogenesis by producing colibactin, a polyketide-peptide genotoxin. However, the functions of pks+ E. coli in initiation, proliferation, and metastasis of colorectal cancer (CRC) remain unclear. We investigated the clinical significance of pks+ E. coli to clarify its functions in CRC. This study included 413 patients with CRC. Pks+ E. coli of tumor tissue and normal mucosal tissue were quantified using droplet digital PCR. Pks+ E. coli was more abundant in Stages 0-I tumor tissue than in normal mucosal tissue or in Stages II-IV tumor tissue. High abundance of pks+ E. coli in tumor tissue was significantly associated with shallower tumor depth (hazard ratio [HR] = 5.0, 95% confidence interval [CI] = 2.3-11.3, p < 0.001) and absence of lymph node metastasis (HR = 3.0, 95% CI = 1.8-5.1, p < 0.001) in multivariable logistic analyses. Pks+ E. coli-low and -negative groups were significantly associated with shorter CRC-specific survival (HR = 6.4, 95% CI = 1.7-25.6, p = 0.005) and shorter relapse-free survival (HR = 3.1, 95% CI = 1.3-7.3, p = 0.01) compared to the pks+ E. coli-high group. Pks+ E. coli was abundant in Stages 0-I CRC and associated with CRC prognosis. These results suggest that pks+ E. coli might contribute to carcinogenesis of CRC but might not be associated with tumor progression.

Oncologic investigation of the interval from stent placement to surgery in patients with obstructive colorectal cancer

PURPOSE

Self-expandable metallic stent (SEMS) placement is widely used as a bridge to surgery (BTS) procedure for obstructive colorectal cancer. However, evidence regarding the optimal interval between SEMS placement and elective surgery is lacking.

METHODS

We retrospectively collected data from patients with BTS between January 2013 and October 2021. Inverse probability treatment-weighted propensity score analyses were used to compare short- and long-term outcomes between the short-interval (SI) and long-interval (LI) groups, using a cutoff of 20 days.

RESULTS

In total, 138 patients were enrolled in this study (SI group, n = 63; LI group, n = 75). In the matched cohort, the patients' backgrounds were well balanced. The incidence of Clavien-Dindo grade ≥ II postoperative complications was not significantly different between the SI and LI groups (19.0% vs. 14.0%, P = 0.47). There were no significant differences between the SI and LI groups in the 3-year recurrence-free survival (68.0% vs. 76.4%, P = 0.73) or 3-year overall survival rates (86.0% vs. 90.6%, P = 0.72).

CONCLUSIONS

A longer interval did not deteriorate the oncological outcomes. Individual perioperative management with an appropriate interval to improve the patient's condition is required to ensure safe surgery.

The empty pelvis syndrome: a core data set from the PelvEx collaborative

BACKGROUND

Empty pelvis syndrome (EPS) is a significant source of morbidity following pelvic exenteration (PE), but is undefined. EPS outcome reporting and descriptors of radicality of PE are inconsistent; therefore, the best approaches for prevention are unknown. To facilitate future research into EPS, the aim of this study is to define a measurable core outcome set, core descriptor set and written definition for EPS. Consensus on strategies to mitigate EPS was also explored.

METHOD

Three-stage consensus methodology was used: longlisting with systematic review, healthcare professional event, patient engagement, and Delphi-piloting; shortlisting with two rounds of modified Delphi; and a confirmatory stage using a modified nominal group technique. This included a selection of measurement instruments, and iterative generation of a written EPS definition.

RESULTS

One hundred and three and 119 participants took part in the modified Delphi and consensus meetings, respectively. This encompassed international patient and healthcare professional representation with multidisciplinary input. Seventy statements were longlisted, seven core outcomes (bowel obstruction, enteroperineal fistula, chronic perineal sinus, infected pelvic collection, bowel obstruction, morbidity from reconstruction, re-intervention, and quality of life), and four core descriptors (magnitude of surgery, radiotherapy-induced damage, methods of reconstruction, and changes in volume of pelvic dead space) reached consensus-where applicable, measurement of these outcomes and descriptors was defined. A written definition for EPS was agreed.

CONCLUSIONS

EPS is an area of unmet research and clinical need. This study provides an agreed definition and core data set for EPS to facilitate further research.

Impact of resection for ovarian metastases from colorectal cancer and clinicopathologic analysis: A multicenter retrospective study in Japan

Aim

The aim of this study was to clarify the significance of resection of ovarian metastases from colorectal cancer and to identify the clinicopathologic characteristics.

Methods

In this multicenter retrospective study, we evaluated data on ovarian metastases from colorectal cancer obtained from patients at 20 centers in Japan between 2000 and 2014. We examined the impact of resection on the prognosis of patients with ovarian metastases and examined prognostic factors.

Results

The study included 296 patients with ovarian metastasis. The 3-y overall survival rate was 68.6% for solitary ovarian metastases. In all cases of this cohort, the 3-y overall survival rates after curative resection, noncurative resection, and nonresection were 65.9%, 31.8%, and 6.1%, respectively (curative resection vs noncurative resection [P < 0.01] and noncurative resection vs nonresection [P < 0.01]). In the multivariate analysis of prognostic factors, tumor size of ovarian metastasis (P < 0.01), bilateral ovarian metastasis (P = 0.01), peritoneal metastasis (P < 0.01), pulmonary metastasis (P = 0.04), liver metastasis (P < 0.01), and remnant of ovarian metastasis (P < 0.01) were statistically significantly different.

Conclusion

The prognosis after curative resection for solitary ovarian metastases was shown to be relatively favorable as Stage IV colorectal cancer. Resection of ovarian metastases, not only curative resection but also noncurative resection, confers a survival benefit. Prognostic factors were large ovarian metastases, bilateral ovarian metastases, the presence of extraovarian metastases, and remnant ovarian metastases.

Prediction model of the risk for lateral local recurrence in locally advanced rectal cancer without enlarged lateral lymph nodes: Lessons from a Japanese multicenter pooled analysis of 812 patients

Aim

Although the oncological impact of lateral lymph node dissection on enlarged lateral lymph nodes has been gradually accepted over the last decade, that on lateral lymph nodes without swelling remains doubtful. This study aimed to develop a prediction model for the future risk of lateral local recurrence and to clarify the value of adding lateral lymph node dissection in locally advanced rectal cancer without enlarged lateral lymph nodes.

Methods

This retrospective, multi-institutional study recruited 812 patients with cStage II/III low rectal cancer without enlarged lateral lymph nodes <7 mm. Total lateral local recurrence was a hypothetical value of future risk of lateral local recurrence when lateral lymph node dissection was never performed.

Results

Overall, total lateral local recurrences were observed in 67 patients (8.3%). In the multivariate analyses, the strongest risk factor for total local recurrences was no preoperative chemoradiotherapy (odds ratio [OR][95%Cl]: 33.2 [4.56-241.7], P < 0.001), followed by tumor distance ≤40 mm (OR [95%Cl]: 2.71 [1.51-4.86], P < 0.001) and lateral lymph node 5-7 mm (OR[95%Cl]: 2.38 [1.26-4.48], P = 0.007). In patients with lateral lymph nodes of 5-7 mm, the total lateral recurrence rate was 4.8% after preoperative chemoradiotherapy. Lateral lymph node dissection could reduce from a total lateral local recurrence of 21.6% to an actual lateral local recurrence of 8.0% in patients without preoperative treatment.

Conclusion

We introduce a novel prediction model of future risk of lateral local recurrences, which has the potential to enable us to indicate lateral lymph node dissection selectively according to the patients' risks.

Successful management of malignant colovesical fistula using covered colonic self-expanding metallic stent: a case report

BACKGROUND

A colovesical fistula (CVF) is commonly treated by resection of the intestine containing the fistula or creation of a defunctioning stoma. We herein report a case of successful fistula closure and avoidance of colostomy after placement of a covered colonic self-expanding metallic stent (SEMS) as a palliative treatment for a malignant CVF.

CASE PRESENTATION

A 75-year-old man undergoing infusional 5-fluorouracil and irinotecan chemotherapy plus bevacizumab for recurrent peritoneal dissemination of rectal cancer was admitted to our hospital because of fecaluria with a high-grade fever. Blood tests showed a moderate inflammatory reaction (white blood cell count, 9200/mm3; C-reactive protein, 11.03 mg/dL; procalcitonin, 1.33 ng/mL). Urinary sediment examination showed severe bacteriuria. Abdominal contrast-enhanced computed tomography showed intravesical gas, thickening of the posterior wall of the bladder, and irregular thickening of the sigmoid colon wall contiguous with the posterior bladder wall. Magnetic resonance imaging (MRI) clearly showed a fistula between the bladder and sigmoid colon. Colonoscopy revealed a circumferential malignant stricture 15 cm from the anal verge, and a fistula to the bladder was identified by water-soluble contrast medium. We diagnosed a complicated urinary tract infection (UTI) associated with a CVF due to peritoneal dissemination and started empirical treatment with sulbactam/ampicillin. Given the absence of active inflammatory findings around the fistula on MRI and the patient's physical frailty, we decided to place a covered SEMS to close the fistula. Under fluoroscopic and endoscopic guidance, a covered colonic SEMS of 80-mm length and 20-mm diameter was successfully deployed, and the fistula was sealed immediately after placement. Urine culture on day 3 after stenting was negative for bacteria, and a contrast study on day 5 showed no fistula. The patient was discharged home on day 6 with no complications. The UTI did not recur for 4 months after discharge.

CONCLUSIONS

A covered colonic SEMS was useful for sealing a malignant CVF in a patient unfit for surgery, and MRI was valuable to determine the status of the fistula. A covered colonic SEMS could be an alternative to surgical treatment for CVFs in patients who require palliative care.

Crohn's Disease-Associated Anorectal Cancer Has a Poor Prognosis With High Local Recurrence: A Subanalysis of the Nationwide Japanese Study

INTRODUCTION

Colorectal cancer (CRC) is one of the major life-threatening complications in patients with Crohn's disease (CD). Previous studies of CD-associated CRC (CD-CRC) have involved only small numbers of patients, and no large series have been reported from Asia. The aim of this study was to clarify the prognosis and clinicopathological features of CD-CRC compared with sporadic CRC.

METHODS

A large nationwide database was used to identify patients with CD-CRC (n = 233) and sporadic CRC (n = 129,783) over a 40-year period, from 1980 to 2020. Five-year overall survival (OS), recurrence-free survival (RFS), and clinicopathological characteristics were investigated. The prognosis of CD-CRC was further evaluated in groups divided by colon cancer and anorectal cancer (RC). Multivariable Cox regression analysis was used to adjust for confounding by unbalanced covariables.

RESULTS

Compared with sporadic cases, patients with CD-CRC were younger; more often had RC, multiple lesions, and mucinous adenocarcinoma; and had lower R0 resection rates. Five-year OS was worse for CD-CRC than for sporadic CRC (53.99% vs 71.17%, P < 0.001). Multivariable Cox regression analysis revealed that CD was associated with significantly poorer survival (hazard ratio 2.36, 95% confidence interval: 1.54-3.62, P < 0.0001). Evaluation by tumor location showed significantly worse 5-year OS and RFS of CD-RC compared with sporadic RC. Recurrence was identified in 39.57% of CD-RC cases and was mostly local.

DISCUSSION

Poor prognosis of CD-CRC is attributable primarily to RC and high local recurrence. Local control is indispensable to improving prognosis.

Renal Dysfunction after Rectal Cancer Surgery: A Long-term Observational Study

Objectives

Despite the high incidence of urinary dysfunction (UD) after rectal surgery, it remains questionable whether UD causes future chronic kidney disease (CKD). This study aimed to clarify the long-term trends in renal function and risk factors for future CKD after rectal resection.

Methods

For comparison, patients who underwent rectal resection (n = 129) and colectomy (n = 127) between 2006 and 2017 were identified. The estimated glomerular filtration rate (eGFR) ratio was calculated as the ratio to the baseline. "eGFR ratio < 0.75 at 3-year" was adopted as a surrogate indicator of future CKD.

Results

eGFR ratio significantly decreased in the rectal cohort compared with the colon cohort at 1.5 years (0.9 vs. 0.95, p = 0.008) and at 3 years (0.85 vs. 0.94, p < 0.001). Although the preoperative prevalence of CKD was lower in the rectal than the colon cohort (13.9% vs. 23.6%, p = 0.055), it was similar at 3 years (29.5% vs. 30.7%). In multivariate analysis, females, and cT4 were independent risk factors for future CKD, but UD itself was not.

Conclusions

Postoperative eGFR significantly decreased after rectal cancer surgery compared to colectomy. The prevalence of CKD more than doubled at 3 years after rectal resection. The female sex and cT4 tumor, instead of the UD, were independent risk factors for future CKD.

Robot-assisted surgery for rectal cancer with solitary sacrococcygeal metastasis after neoadjuvant chemoradiotherapy: A case report

An 81-year-old man was referred to our hospital for anal bleeding. Colonoscopy revealed a type 3 tumor at the upper rectum and biopsy showed adenocarcinoma. An enhanced circumferential lesion at the upper rectum and a solitary soft-tissue shadow at the fifth sacral vertebra to the coccyx were detected on abdominal magnetic resonance imaging. Fluorodeoxyglucose uptake was observed at the same sites on positron emission tomography. The patient was diagnosed with rectal cancer with isolated sacrococcygeal metastasis and was treated with neoadjuvant chemoradiotherapy followed by robotic surgery. Hartmann's operation was performed in the lithotomy position. The left internal iliac artery and vein were then divided. The internal pudendal artery and vein, the piriformis muscle, and sacrospinous ligament were also divided while preserving the lumbosacral trunk. The scheduled transection line of the sacral surface was fully exposed to prevent massive bleeding during sacrectomy. The dorsal surface of the sacrum was then exposed in the prone position and communicated with the pelvic space. The sacrum was transected at the superior margin of S3 and a specimen was extracted. Pathological findings revealed the infiltration of cancer cells in the sacrococcygeal specimen. The postoperative course was uneventful and the patient was discharged on postoperative day 13.

Early Prediction of a Serious Postoperative Course in Perihilar Cholangiocarcinoma: Trajectory Analysis of the Comprehensive Complication Index

OBJECTIVE

The aim of this study was to visualize the postoperative clinical course using the comprehensive complication index (CCI) and to propose an early alarming sign for subsequent serious outcomes in perihilar cholangiocarcinoma.

BACKGROUND

Surgery for this disease carries a high risk of morbidity and mortality. The developmental course of the overall morbidity burden and its clinical utility are unknown.

METHODS

Patients who underwent major hepatectomy for perihilar cholan-giocarcinoma between 2010 and 2019 were reviewed retrospectively. All postoperative complications were evaluated according to the Clavien-Dindo classification (CDC), and the CCI was calculated on a daily basis until postoperative day 14 to construct an accumulating graph as a trajectory. Group-based trajectory modeling was conducted to categorize the trajectory into clinically distinct patterns and the predictive power of early CCI for a subsequent serious course was assessed.

RESULTS

A total of 4230 complications occurred in the 484 study patients (CDC grade I, n = 27; II, n = 132; IlIa, n = 290; IIIb, n = 4; IVa, n = 21; IVb, n = 1; and V, n = 9). The trajectory was categorized into 3 patterns: mild (n = 209), moderate (n = 235), and severe (n = 40) morbidity courses. The 90-day mortality rate significantly differed among the courses: 0%, 0.9%, and 17.5%, respectively (P<0.001). The cutoff values of the CCI on postoperative days 1, 4, and 7 for predicting a severe morbidity course were 15.0, 28.5, and 40.6 with areas under the curves of 0.780, 0.924, and 0.984, respectively.

CONCLUSIONS

The CCI could depict the chronological increase in the overall morbidity burden, categorized into 3 patterns. Early CCI potentially predicted sequential progression to serious outcomes.

Cyclodextrin Conjugated α-Bisabolol Suppresses FAK Phosphorylation and Induces Apoptosis in Pancreatic Cancer

BACKGROUND/AIM

α-Bisabolol is an essential oil component extracted from plants, such as chamomile. We have previously reported that α-bisabolol suppressed proliferation, invasion, and motility of pancreas cancer. Cyclodextrin improved the solubility of α-bisabolol, therefore it enabled to administer intravenously. The aim of this study was to clarify the effect of cyclodextrin conjugated α-bisabolol (CD-BSB) and the signals pathways associated with α-bisabolol for pancreatic cancer.

MATERIALS AND METHODS

Human pancreatic cancer cell lines were treated with or without CD-BSB. Cytomorphology and apoptosis were assessed in these treated groups. In addition, several phosphorylated proteins were analyzed to clarify the signal pathway concerning CD-BSB. In subcutaneous xenograft model, tumor volume and Ki-67 expression were evaluated among Control (untreated), CD-BSB, or Gemcitabine (GEM).

RESULTS

CD-BSB significantly changed cytomorphology and induced apoptosis in pancreatic cancer cells. CD-BSB suppressed phosphorylation of focal adhesion kinase (FAK). In addition, pFAK 397 was inhibited by CD-BSB in a concentration-dependent manner in cancer cells. In the subcutaneous xenograft models, the tumor volume in the CD-BSB groups was lower than Control groups. Ki67-positive cells in CD-BSB treated group were lower than the GEM-treated groups.

CONCLUSION

We clarified the efficiency of CD-BSB in xenograft tumor using intravenous administration. α-Bisabolol suppresses phosphorylation of FAK 397 and impairs cytoskeletal polymerization in a pancreatic cancer cell line. Further investigations are required to reveal the precise mechanisms of the antitumor effects of solubilized α-bisabolol to facilitate its clinical application. Our data indicate that solubilized α-bisabolol has therapeutic potential and could improve the prognosis of cancer patients.

Antitumor Effects of Deep Ultraviolet Irradiation for Pancreatic Cancer

BACKGROUND/AIM

Deep ultraviolet (DUV) light spans within the 250 nm to 350 nm invisible wavelength range. Although it strongly damages various cells, the efficacy of DUV irradiation on pancreatic cancer cells has never been clarified. The purpose of this study was to reveal the antitumor effects of DUV irradiation on pancreatic cancer cells.

MATERIALS AND METHODS

Human pancreatic cancer cell lines were eradicated with DUV or ultraviolet A (UVA) for 5 s. Several angiogenesis-related proteins were studied in cancer cells after DUV irradiation using a protein antibody array. A subcutaneous xenograft model was established by inoculation of pancreatic cancer cells into mice. Tumors in this model were irradiated with DUV or UVA once or twice for two weeks. Tumor volumes in these groups (DUV×1: one irradiation, DUV×2: two irradiations, and untreated) were analyzed one week after the second irradiation.

RESULTS

DUV irradiation significantly changed the cytomorphology of pancreatic cancer cells. In addition, DUV irradiation induced apoptosis on pancreatic cancer cells more strongly than UVA irradiation and no irradiation. Interestingly, lower expression of thrombospondin 1 (TSP1) and tissue inhibitor of metalloproteinase 1 (TIMP1) was identified after DUV treatment. The tumor volume in the DUV-treated groups (DUV×1 and DUV×2) was smaller than that in the untreated group.

CONCLUSION

Further investigations are required to reveal the precise mechanisms of the antitumor effects of DUV irradiation and to facilitate its clinical application as a new therapy for pancreatic cancer. Overall, DUV irradiation can be potentially used as a therapeutic option of pancreatic malignancy.

Ensemble study: A multicenter, randomized, phase III trial to test the superiority of consolidation irinotecan, capecitabine and oxaliplatin vs capecitabine and oxaliplatin following short course radiotherapy as total neoadjuvant therapy in patients with locally advanced rectal cancer

TPS276

Background: Non-operative management (NOM) may enable more patients (pts) with a complete clinical response (cCR) or near-complete clinical response (nCR) after total neoadjuvant therapy (TNT) for locally advanced rectal cancer (LARC) to avoid subsequent radical surgery, possibly maintaining the anorectal function and quality of life (QoL). The PRODIGE-23 trial demonstrated that triplet regimen before chemoradiotherapy (CRT) significantly improved outcomes in comparison to CRT. However, there have been no prospective studies of consolidation triplet versus doublet regimens following short course radiotherapy (SCRT). This randomized phase III trial aimed to test the superiority of consolidation CAPOXIRI vs. CAPOX after SCRT as TNT in pts with LARC. Methods: Pts of >18 years of age, with an ECOG PS of 0-1, biopsy-proven newly diagnosed primary LARC (<12 cm from anal verge [AV]), stage cT3-4N0M0 or cTanyN1-2M0 are eligible for inclusion. Pts with known MSI-H or dMMR are excluded. Eligible pts are centrally randomized (1:1) by the minimization method with stratification by institution, cT1-3 vs. cT4, cN- vs. cN+ and AV of < 5 vs. >5 cm. The experimental treatment group receives SCRT (5 × 5 Gy) followed by six cycles of CAPOXIRI (capecitabine 800 mg/m2 [orally, twice daily, day 1-14], oxaliplatin 130 mg/m2 [intravenously, day 1] and irinotecan 200 mg/m2 [intravenously, day 1, q3wks]). The standard-of-care group receives SCRT (5 × 5 Gy) followed by six cycles of CAPOX (capecitabine 1000 mg/m2 [orally, twice daily, day 1-14], oxaliplatin 130 mg/m2 [intravenously, day 1, q3wks]). All patients will be restaged after completing TNT before radical surgery according to the Memorial Sloan Kettering Regression Schema; pts with an incomplete response (iCR) will undergo total mesorectal excision (TME), cCR pts will receive NOM, and nCR pts will undergo TME or NOM at the physician’s discretion under the recommendation of blind assessment by the designated NOM central committee. Pts will be followed by CT, MRI, colonoscopy and liquid biopsy every 4 months for 2 years, then every 6 months to 5 years. The primary endpoint is organ preservation-adapted disease-free survival (DFS) in the intention-to-treat population. To detect a decrease in 3-year cumulative probability of organ preservation-adapted DFS from 75.0% to 80.6%, corresponding to a target hazard ratio of 0.75, 608 pts (196 events) would achieve 70% power at a two-sided α of 0.05. Key secondary endpoints include DFS, overall survival, adverse events and QoL. Translational research includes genomic profiling with whole genome/transcriptome sequencing of tissue and blood samples, and the establishment of NOM predictor by deep learning. This study will start in October 2022. Clinical trial information: jRCTs031220342 .

Impact of preoperative muscle mass and quality on surgical outcomes in patients undergoing major hepatectomy for perihilar cholangiocarcinoma

PURPOSES

This study sought to define the impact of skeletal muscle mass and quality on postoperative outcomes in patients with perihilar cholangiocarcinoma.

METHODS

Patients who underwent major hepatectomy for perihilar cholangiocarcinoma were included. The normalized total psoas area (TPA) (psoas muscle index [PMI]) and average Hounsfield units of the TPA (psoas muscle density [PMD]) were measured using preoperative computed tomography images. The cohort was dichotomized using the following indices: sex-specific lowest tertile (low PMI and low PMD) and other (normal PMI and normal PMD). Intraoperative and postoperative outcomes were compared, focusing on PMI and PMD.

RESULTS

A total of 456 patients were analyzed. The intraoperative blood loss (IBL) was 21.3 ml/kg in the low PMI group and 17.2 ml/kg in the normal PMI group (P = .008). Patients in the low PMI or PMD group experienced postoperative infectious complications more frequently than those in the other groups. The median survival time was 37.8 months in the low PMI group and 54.2 months in the normal PMI group (P = .027).

CONCLUSIONS

PMI and PMD were closely associated with IBL and postoperative infectious complications. Additionally, PMI impacted long-term survival. These results suggest an importance of improving muscle mass and quality before surgery.

Current status of transanal total mesorectal excision for rectal cancer and the expanding indications of the transanal approach for extended pelvic surgeries

Transanal total mesorectal excision (taTME) has been rapidly accepted as a promising surgical approach to the distal rectum. The benefits include ease of access to the bottom of the deep pelvis linearly over a short distance in order to easily visualize the important anatomy. Furthermore, the distal resection margins can be secured under direct vision. Additionally, a two-team approach combining taTME with a transabdominal approach could decrease the operative time and conversion rate. Although taTME was expected to become more rapidly popularized worldwide, enthusiasm for it has stalled due to unfamiliar intraoperative complications, a lack of oncologic evidence from randomized trials, and the widespread use of robotic surgery. While international registries have reported favorable short- and medium-term outcomes from taTME, a Norwegian national study reported a high local recurrence rate of 9.5%. The characteristics of the recurrences included rapid, multifocal growth in the pelvis, which was quite different from recurrences following traditional transabdominal TME; thus, the Norwegian Colorectal Cancer Group reached a consensus for a temporary moratorium on the performance of taTME. To ensure acceptable baseline quality and patient safety, taTME should be performed by well-trained colorectal surgeons. Although the appropriate indications for taTME remain controversial, the transanal approach is extremely important as a means of goal setting in difficult TME cases and as an aid to the transabdominal approach in various types of extended pelvic surgeries. The benefits in transanal lateral lymph node dissection and pelvic exenteration are presented herein.

Optimal diagnostic criteria for lateral lymph node dissection using magnetic resonance imaging: a multicenter prospective study

BACKGROUND

LLND in cases with suspected lateral lymph node (LLN) metastasis has been focused on as a novel treatment strategy in recent years. However, the optimal indication for LLND in rectal cancer patients has not been determined. This study aimed to establish the optimal indication for lateral lymph node dissection (LLND) in patients with rectal cancer using magnetic resonance imaging (MRI).

METHODS

A total of 209 patients with rectal adenocarcinoma who underwent total mesorectal excision and LLND in 13 hospitals were prospectively registered. By matching the sizes of the harvested LNs and those in magnetic resonance imaging (MRI), the pathological outcome of each LN was confirmed one-by-one. Using parameters of the LLNs in MRI, the optimal diagnostic criteria for LLND were established.

RESULTS

Of 3241 harvested LLNs, including 83 metastatic nodes, 1010 (31.1%) were visualized on MRI. Although all parameters assessed showed strong correlations with the presence of metastasis, none of these parameters could discriminate metastatic LLNs from non-metastatic nodes with sufficient sensitivity. However, by using the combination of long axis and short/long ratio in pretreatment MRI, we could establish optimal criteria for LLND. The sensitivity and specificity of the criteria for LLN metastasis were 94.3% and 40.2%, respectively.

CONCLUSIONS

In conclusion, we established novel criteria for LLND in rectal cancer patients using MRI. Our criteria will be of great clinical use in determining indications for LLND.

Minimum standards of pelvic exenterative practice: PelvEx Collaborative guideline

This document outlines the important aspects of caring for patients who have been diagnosed with advanced pelvic cancer. It is primarily aimed at those who are establishing a service that adequately caters to this patient group. The relevant literature has been summarized and an attempt made to simplify the approach to management of these complex cases.

Early volume loss of skeletal muscle after esophagectomy: a risk for late-onset postoperative pneumonia

Late-onset postoperative pneumonia (LOPP) after esophagectomy is poorly understood. This study was designed to clarify the features and risk factors for this event. Patients who underwent esophagectomy for esophageal cancer between 2006 and 2016 were included. LOPP was defined as radiologically proven pneumonia that occurred over 3 months after surgery, and clinically relevant late-onset postoperative pneumonia (CR-LOPP) was defined as LOPP that required administration of oxygen and antibiotics in the hospital and/or more intensive treatment. The total psoas muscle area (TPA) was measured using preoperative and postoperative (at 3 months after surgery) computed tomography scan images. Potential risk factors for CR-LOPP were investigated. Among 175 study patients, 46 (26.3%) had LOPP, 29 (16.6%) of whom exhibited CR-LOPP with a cumulative incidence of 15.6% at 3 years and 22.4% at 5 years. Four (13.8%) of these patients died of LOPP. Univariable analysis showed that clinical stage ≥III (P = 0.005), preoperative prognostic nutritional index (PNI) <45 (P = 0.035), arrhythmia (P = 0.014), postoperative hospital stay ≥40 days (P = 0.003), and percent decrease of TPA more than 5% (P < 0.001) were associated with CR-LOPP but not early onset postoperative pneumonia. Multivariable analysis revealed that clinical stage ≥III (hazard ratio [HR] 3.01, P = 0.004), postoperative hospital stay ≥40 days (HR 2.51, P = 0.015), and percent decrease of TPA >5% (HR 9.93, P < 0.001) were independent risk factors for CR-LOPP. CR-LOPP occurred in over 20% of patients at 5 years, and early postoperative loss of TPA was a potential trigger for this delayed complication.

Management of inguinal lymph node metastases from rectal and anal canal adenocarcinoma

AIM

The surgical treatment of inguinal lymph node (ILN) metastases secondary to anorectal adenocarcinoma remains controversial. This study aimed to clarify the surgical treatment and management of ILN metastasis according to its classification.

METHODS

This retrospective, multi-centre, observational study included patients with synchronous or metachronous ILN metastases who were diagnosed with rectal or anal canal adenocarcinoma between January 1997 and December 2011. Treatment outcomes were analysed according to recurrence and prognosis.

RESULTS

Among 1181 consecutively enrolled patients who received treatment for rectal or anal canal adenocarcinoma at 20 referral hospitals, 76 (6.4%) and 65 (5.5%) had synchronous and metachronous ILN metastases, respectively. Among 141 patients with ILN metastasis, differentiated carcinoma, solitary ILN metastasis and ILN dissection were identified as independent predictive factors associated with a favourable prognosis. No significant difference was found in the frequency of recurrence after ILN dissection between patients with synchronous (80.6%) or metachronous (81.0%) ILN metastases. Patients who underwent R0 resection of the primary tumour and ILN dissection had a 5-year survival rate of 41.3% after ILN dissection (34.1% and 53.1% for patients with synchronous and metachronous ILN metastases, respectively, P = 0.55).

CONCLUSION

The ILN can be appropriately classified as a regional lymph node in rectal and anal canal adenocarcinoma. Moreover, aggressive ILN dissection might be effective in improving the prognosis of low rectal and anal canal adenocarcinoma with ILN metastases; thus, prophylactic ILN dissection is unnecessary.

Japanese multicenter prospective study investigating laparoscopic surgery for locally advanced rectal cancer with evaluation of CRM and TME quality (PRODUCT trial)

Aim

In Japan, we have not been able to validate the results of laparoscopic surgery for locally advanced rectal cancer using the universal index “circumferential resection margin (CRM).” Previously, we established a semi‐opened circular specimen processing method and validated its feasibility. In the PRODUCT trial, we aimed to assess CRM in patients with locally advanced rectal cancer who underwent laparoscopic rectal resection.

Methods

This was a multicenter, prospective, observational study. Eligible patients had histologically confirmed rectal adenocarcinoma located at or below 12 cm above the anal verge with clinical stage II or III and were scheduled for laparoscopic or robotic surgery. The primary endpoint was pathological CRM. CRM ≤1 mm was defined as positive.

Results

A total of 303 patients operated on between August 2018 and January 2020 were included in the primary analysis. The number of patients with clinical stage II and III was 139 and 164, respectively. Upfront surgery was performed for 213 patients and neoadjuvant therapy for 90 patients. The median CRM was 4.0 mm (IQR, 2.1‐8.0 mm), and CRM was positive in 26 cases (8.6%). Univariate and multivariate analyses demonstrated that a predicted CRM from the mesorectal fascia of ≤1 mm on MRI was the significant factor for positive CRM (P = .0012 and P = .0045, respectively).

Conclusion

This study showed the quality of laparoscopic rectal resection based on the CRM in Japan. Preoperative MRI is recommended for locally advanced rectal cancer to prevent CRM positivity.

A proposal of drain removal criteria in hepatobiliary resection

BACKGROUND

Standardized criteria for the drain removal in hepatobiliary resection are lacking. We evaluated the outcomes of delayed removal policy in this extended surgery.

METHODS

Patients undergoing hepatectomy with biliary reconstruction between 2012 and 2018 were retrospectively reviewed. The drains were removed on postoperative day (POD) 7 when the drainage fluid was grossly serous, biochemically normal, and negative for bacterial contamination as assessed by Gram staining; additionally, no abnormal fluid collection was confirmed by computed tomography. Clinically relevant abdominal complications (CRACs), including biliary leakage, pancreatic fistula or intra-abdominal abscess, served as the primary outcome measure.

RESULTS

Among 374 study patients, surgical drains were removed in 166 (44.3%) patients who met the criteria. Of these patients, 16 (9.6%) patients required additional drainage afterwards due to CRAC. Drains were retained and exchanged in 208 (55.6%) patients who did not meet the criteria. Of them, exchanged drains were soon removed in 34 patients due to no signs of CRAC. The diagnostic ability of the criteria revealed 0.916 sensitivity, 0.815 specificity, and 0.866 accuracy.

CONCLUSION

The four findings on POD 7 worked well as criteria for drain removal, and these criteria may be helpful in drain management after hepatobiliary resection.

Direct Observation of Retinal Microvessels in Cancer Patients After Systemic Administration of Bevacizumab and Oxaliplatin

BACKGROUND/AIM

Antiangiogenic chemotherapy is the backbone of the various anticancer therapies. To date no practical biomarker predicting their antitumor effects and toxicity has been reported. We aimed to determine the feasibility of direct retinal observation as a practical biomarker in antiangiogenic chemotherapy.

PATIENTS AND METHODS

By direct retinal observation using a nonmydriatic retinal camera, we measured retinal microvessel diameters in 10 patients with colorectal cancer before and after intravenous infusion of bevacizumab and oxaliplatin. All patients also received oral capecitabine during their therapy.

RESULTS

Retinal microvessel diameters were decreased from baseline temporarily by 14.5±6.5% after infusion of bevacizumab and oxaliplatin in five patients who responded to treatment and 8.8±6.2% in the other five patients (p=0.008).

CONCLUSION

Measurement of retinal microvessel diameters by direct observation appears to be feasible in patients receiving systemic chemotherapy. The decrease of retinal microvessel diameters might indicate improved tumor response to treatment with bevacizumab-containing systemic chemotherapy.

Role of resection for extrahepatopulmonary metastases of colon cancer

BACKGROUND

Although surgical resection for liver or lung metastases of colorectal cancer has been widely accepted, the use of this approach for extrahepatopulmonary metastases remains debatable due to the systemic nature of the disease. The aim of this study was to clarify the utility of resection along with perioperative chemotherapy for patients with extrahepatopulmonary metastases of colon cancer.

METHODS

This is a retrospective single-arm study at a single institution. Forty-two patients with resectable extrahepatopulmonary metastases who underwent metastasectomy with curative intent between 2009 and 2018 at Nagoya University Hospital were retrospectively analyzed. The primary outcomes measured were overall and relapse-free survival.

RESULTS

The most common metastatic site was the peritoneum (n = 31), followed by the distant lymph nodes (n = 10), ovary (n = 1) and spleen (n = 1), with overlaps. Preoperative and postoperative chemotherapies were administered to 22 and 8 patients, respectively; the remaining 14 patients received surgery alone. R0 resection was achieved in 36 patients (85.7%). The 5-year overall survival and 3-year relapse-free survival rates were 58.6% and 33.8%, respectively. In the univariate analysis, R1 resection was associated with a poor relapse-free survival rate (P = 0.02). In the multivariate analysis, the absence of perioperative chemotherapy was an independent risk factor for poor overall survival rates (P = 0.02).

CONCLUSIONS

Surgical resection benefited selected patients with extrahepatopulmonary metastases with favorable long-term survival outcomes. Surgery alone without systemic chemotherapy is likely to bring poor outcome; therefore, preoperative induction might be promising to keep up with chemotherapy.

Feasibility of the semi-opened method of specimen resection for a circumferential resection margin in rectal cancer surgery: a multicenter study

PURPOSE

A circumferential resection margin (CRM) > 1 mm is a surrogate marker of oncologic outcomes in rectal cancer patients. In Japan, because the mesentery is removed from the rectum, the CRM cannot be measured. This multicenter prospective study evaluates the feasibility of a resected specimen processing method that allows CRM measurement.

METHODS

Fifty patients with rectal cancer were enrolled. Resected specimens were processed as previously reported. The primary outcomes were CRM measurement and the rate of CRM positivity. The secondary outcomes were the quality of total mesorectal excision, the possibility to visualize and sample the tumor, the number of harvested lymph nodes, and comparison between the pathological CRM and preoperative mesorectal fascia (MRF) involvement. This study was registered in the University Hospital Medical Information Network (UMIN) Clinical Trials Registry under identification number UMIN000031735.

RESULTS

The CRM was measurable in all patients and found to be positive in three (6%). We confirmed tumor localization, sampled the tumor, and measured the distal margin in all patients. A median of 20 lymph nodes were harvested. The concordance rate between preoperative MRF involvement and pathological CRM status was 90%.

CONCLUSION

A semi-opened rectal specimen with transverse slicing is a feasible method for measuring the CRM.

Stoma creation is associated with a low incidence of midline incisional hernia after colorectal surgery: the "fighting over the fascia" theory concerning the incision and stoma hole

PURPOSE

Parastomal hernia (PH) develops more frequently than incisional hernia (IH) after colorectal surgery with stoma. This study evaluated our hypothesis that inward traction of the fascia when closing a midline incision widens the stoma hole and increases the incidence of PH.

METHODS

A total of 795 patients who underwent colorectal resection between 2006 and 2016 were retrospectively analyzed. The risk classification was constructed from IH risk factors extracted from the non-stoma group. Then, the classification was extrapolated to the stoma group for predicting midline IH and PH.

RESULTS

The incidence of IH was 5.3% in the stoma group and 12.5% in the non-stoma group (p = 0.005). PH developed in 19.6% of 97 patients with permanent stoma. The risk classification was able to predict PH without a significant difference but was well balanced in patients with permanent stoma; however, it failed to predict IH in the stoma group.

CONCLUSION

The risk classification constructed from the non-stoma group was useful for predicting not midline IH but PH, suggesting that the stoma site was the most vulnerable for herniation. The "fighting over the fascia" theory between the midline incision and stoma hole may explain the causal relationship between the midline IH and PH.

High accuracy spectroscopy of 3- and 4-body Λ hypernuclei at Jefferson Lab

JLab E12-19-002 Experiment is planned to measure the Λ-binding energies of 3ΛH [Jπ = 1/2+ or 3/2+(T = 0)] and 4ΛH (1+) at JLab Hall C. The expected accuracy for the binding-energy measurement is |ΔBtotal Λ | ≃ 70 keV. The accurate spectroscopy for these light hypernuclei would shed light on the puzzle of the small binding energy and short lifetime of 3ΛH, and the chargesymmetry breaking in the ΛN interaction. We aim to perform the experiment in 2025.

Study of Λn FSI with Λ quasi-free productions on the 3H(e, e′K+)X reaction at JLab

Abstract. An nnΛ is a neutral baryon system with no charge. The study of the pure Λ-neutron system such as nnΛ gives us information on the Λn interaction. The nnΛ search experiment (E12-17-003) was performed at JLab Hall A in 2018. In this article, the Λn FSI was investigated by a shape analysis of the 3H(e, e′K+)X missing mass spectrum, and a preliminary result for the Λn FSI study is given.

Cross-section measurement of virtual photoproduction of iso-triplet three-body hypernucleus, Λnn

Missing-mass spectroscopy with the 3H(e, e′K+) reaction was carried out at Jefferson Lab’s (JLab) Hall A in Oct–Nov, 2018. The differential cross section for the 3H(γ∗, K+)Λnn was deduced at ω = Ee − Ee′ = 2.102 GeV and at the forward K+-scattering angle (0° ≤ θγ∗K ≤ 5°) in the laboratory frame. Given typical predicted energies and decay widths, which are (BΛ, Γ) = (−0.25, 0.8) and (−0.55, 4.7) MeV, the cross sections were found to be 11.2 ± 4.8(stat.)+4.1−2.1(sys.) and 18.1 ± 6.8(stat.)+4.2−2.9(sys.) nb/sr, respectively. The obtained result would impose a constraint for interaction models particularly between Λ and neutron by comparing to theoretical calculations.

Study of the Λ/Σ0 electroproduction in the low-Q2 region at JLab

We performed an experiment using tritium and hydrogen cryogenic gas targets at Thomas Jefferson National Accelerator Facility (JLab) in 2018 (E12-17-003)[1, 2]. In this article, we discuss the Λ/Σ0 hyperon electroproduction from hydrogen target. Elementary Λ/Σ0 hyperon production processes are important not only for an absolute mass scale calibration in our experiment, but also for the study of the electroproduction mechanisms themselves. In this article, we reported the results of the differential cross section for the p(e, e’K+)Λ/Σ0 reaction at Q2 ∼ 0.5 (GeV/c)2.

Superiority of clinical American Joint Committee on Cancer T classification for perihilar cholangiocarcinoma

BACKGROUND

Clinical tumor staging is essential information for making a therapeutic decision in cancer. This study aimed to identify the optimal tumor classification system for predicting resectability and survival probability in perihilar cholangiocarcinoma.

METHODS

Patients who were treated for perihilar cholangiocarcinoma between 2009 and 2018 were enrolled. Local tumor extension was staged radiologically according to a diameter-based classification system in addition to the AJCC, Blumgart, and Bismuth systems. Survival and resectability were compared between T subgroups, and the discriminability of the four systems was assessed with Harrell's concordance index (C-index).

RESULTS

Among 702 study patients, 559 (80.0%) underwent laparotomy, 489 (70.0%) of whom underwent resection. The resectability significantly decreased for more advanced tumors in all systems (P < .001); the AJCC system had the greatest discriminability for resectability (area under the curve 0.721). Overall survival at 5 years was 69.9% for AJCC cT1, 45.8% for cT2, 31.8% for cT3, and 15.3% for cT4 tumors (cT1 vs cT2; P = .002, cT2 vs cT3; P = .008 and cT3 vs cT4; P < .001). The AJCC system had the largest C-index of 0.627.

CONCLUSIONS

The AJCC T system was the optimal classification system for predicting resectability and survival in perihilar cholangiocarcinoma.

Outcomes of robot-assisted versus conventional laparoscopic low anterior resection in patients with rectal cancer: propensity-matched analysis of the National Clinical Database in Japan

BACKGROUND

Robot-assisted laparoscopic surgery has several advantages over conventional laparoscopy. However, population-based comparative studies for low anterior resection are limited. This article aimed to compare peri-operative results of robot-assisted low anterior resection (RALAR) and laparoscopy.

METHODS

This retrospective cohort study used data from patients treated with RALAR or conventional laparoscopic low anterior resection (CLLAR) between October 2018 and December 2019, as recorded in the Japanese National Clinical Database, a data set registering clinical information, perioperative outcomes, and mortality. Of note, the registry does not include information on the tumour location (centimetres from the anal verge) and diverting stoma creation. Perioperative outcomes, including rate of conversion to open surgery, were compared between RALAR and CLLAR groups. Confounding factors were adjusted for using propensity score matching.

RESULTS

Of 21 415 patients treated during the study interval, 20 220 were reviewed. Two homogeneous groups of 2843 patients were created by propensity score matching. The conversion rate to open surgery was significantly lower in the RALAR group than in the CLLAR group (0.7 versus 2.0 per cent; P < 0.001). The RALAR group had a longer operating time (median: 352 versus 283 min; P < 0.001), less intraoperative blood loss (15 versus 20 ml; P < 0.001), a lower in-hospital mortality rate (0.1 versus 0.5 per cent; P = 0.007), and a shorter postoperative hospital stay (median: 13 versus 14 days; P < 0.001) compared with the CLLAR group. The CLLAR group had a lower rate of readmission within 30 days (2.4 versus 3.3 per cent; P = 0.045).

CONCLUSION

These data highlight the reduced conversion rate, in-hospital mortality rate, intraoperative blood loss, and length of postoperative hospital stay for rectal cancer surgery in patients treated using robot-assisted laparoscopic surgery compared with laparoscopic low anterior resection.

Rectal cancer lateral lymph nodes: multicentre study of the impact of obturator and internal iliac nodes on oncological outcomes

BACKGROUND

In patients with rectal cancer, enlarged lateral lymph nodes (LLNs) result in increased lateral local recurrence (LLR) and lower cancer-specific survival (CSS) rates, which can be improved with (chemo)radiotherapy ((C)RT) and LLN dissection (LLND). This study investigated whether different LLN locations affect oncological outcomes.

METHODS

Patients with low cT3-4 rectal cancer without synchronous distant metastases were included in this multicentre retrospective cohort study. All MRI was re-evaluated, with special attention to LLN involvement and response.

RESULTS

More advanced cT and cN category were associated with the occurrence of enlarged obturator nodes. Multivariable analyses showed that a node in the internal iliac compartment with a short-axis (SA) size of at least 7 mm on baseline MRI and over 4 mm after (C)RT was predictive of LLR, compared with a post-(C)RT SA of 4 mm or less (hazard ratio (HR) 5.74, 95 per cent c.i. 2.98 to 11.05 vs HR 1.40, 0.19 to 10.20; P < 0.001). Obturator LLNs with a SA larger than 6 mm after (C)RT were associated with a higher 5-year distant metastasis rate and lowered CSS in patients who did not undergo LLND. The survival difference was not present after LLND. Multivariable analyses found that only cT category (HR 2.22, 1.07 to 4.64; P = 0.033) and margin involvement (HR 2.95, 1.18 to 7.37; P = 0.021) independently predicted the development of metastatic disease.

CONCLUSION

Internal iliac LLN enlargement is associated with an increased LLR rate, whereas obturator nodes are associated with more advanced disease with increased distant metastasis and reduced CSS rates. LLND improves local control in persistent internal iliac nodes, and might have a role in controlling systemic spread in persistent obturator nodes.Members of the Lateral Node Study Consortium are co-authors of this study and are listed under the heading Collaborators.

The carcinoembryonic antigen ratio is a potential predictor of survival in recurrent colorectal cancer

BACKGROUND

The carcinoembryonic antigen (CEA) "value" itself is often useless in patients with a normal CEA level at initial presentation and those with tumor-irrelevant elevated CEA. Although the unified marker using CEA has been desirable for recurrent tumor staging as well as for primary tumor staging, little is known concerning its relationship with the survival of patients with recurrent colorectal cancer in particular.

METHODS

This retrospective historical study included patients who experienced disease relapse after curative surgery for stage I-III colorectal cancer between 2006 and 2018. A total of 129 patients with recurrent disease after curative surgery for colorectal cancer were included. We focused on the CEA "ratio" (CEA-R: the ratio of the CEA level at the time of recurrence to that measured 3 months before recurrence) and aimed to evaluate the correlation between CEA-R and survival in recurrent colorectal cancer.

RESULTS

Patients with a high CEA-R (≥ 2) exhibited significantly worse 2 year survival than those with a low CEA-R (< 2) (88.1% vs. 44.9%, P < 0.001), irrespective of the CEA value before primary resection. Multivariate analyses demonstrated that the CEA-R (HR; 3.270, 95% CI 1.646-6.497, P = 0.001) was a significant prognostic factor.

CONCLUSION

The CEA-R is a potential marker stratifying the survival of patients with disease relapse who exhibit aggressive biology at recurrent disease foci. As a novel marker, the CEA-R would serve as a clinical guide for tailoring treatment strategies at the time of disease relapse in patients with colorectal cancer.

The Balance of Stromal BMP Signaling Mediated by GREM1 and ISLR Drives Colorectal Carcinogenesis

BACKGROUND & AIMS

Cancer-associated fibroblasts (CAFs), key constituents of the tumor microenvironment, either promote or restrain tumor growth. Attempts to therapeutically target CAFs have been hampered by our incomplete understanding of these functionally heterogeneous cells. Key growth factors in the intestinal epithelial niche, bone morphogenetic proteins (BMPs), also play a critical role in colorectal cancer (CRC) progression. However, the crucial proteins regulating stromal BMP balance and the potential application of BMP signaling to manage CRC remain largely unexplored.

METHODS

Using human CRC RNA expression data, we identified CAF-specific factors involved in BMP signaling, then verified and characterized their expression in the CRC stroma by in situ hybridization. CRC tumoroids and a mouse model of CRC hepatic metastasis were used to test approaches to modify BMP signaling and treat CRC.

RESULTS

We identified Grem1 and Islr as CAF-specific genes involved in BMP signaling. Functionally, GREM1 and ISLR acted to inhibit and promote BMP signaling, respectively. Grem1 and Islr marked distinct fibroblast subpopulations and were differentially regulated by transforming growth factor β and FOXL1, providing an underlying mechanism to explain fibroblast biological dichotomy. In patients with CRC, high GREM1 and ISLR expression levels were associated with poor and favorable survival, respectively. A GREM1-neutralizing antibody or fibroblast Islr overexpression reduced CRC tumoroid growth and promoted Lgr5⁺ intestinal stem cell differentiation. Finally, adeno-associated virus 8 (AAV8)-mediated delivery of Islr to hepatocytes increased BMP signaling and improved survival in our mouse model of hepatic metastasis.

CONCLUSIONS

Stromal BMP signaling predicts and modifies CRC progression and survival, and it can be therapeutically targeted by novel AAV-directed gene delivery to the liver.

The significance of the time to arterial perfusion in intraoperative ICG angiography during colorectal surgery

BACKGROUND

Intraoperative indocyanine green angiography (ICG-A) is a promising tool to confirm blood supply; however, the assessment is difficult without clear demarcation. In this study, the clinical impact of the time to arterial perfusion (TAP) on anastomotic leakage (AL) was evaluated, especially in patients without ICG demarcation.

METHODS

The TAP was assessed using ICG-A during colorectal surgery in 110 patients. ICG demarcation required changing the transection line, and the TAP was measured at the new stump. The patients were divided into marginal flow (MF) and direct flow (DF) groups according to the arterial route. Delayed TAP was defined as the third quartile or slower TAP in each group.

RESULTS

Sixty-six patients (60%) were classified into the MF group, including 64 patients who underwent rectal or sigmoid resection with high ligation of the inferior mesenteric artery. The cut-off value of the delayed TAP in the MF group was significantly slower than that in the DF group (30 and 22 s, respectively, p < 0.001). In the entire cohort, the transection line was changed in 2 patients, resulting in no AL. Nevertheless, AL still developed in 6 patients (5.4%), 5 of whom were in the MF group, and delayed TAP was found in 5 of 6 patients. Delayed TAP was significantly associated with AL in the MF group (p = 0.046).

CONCLUSIONS

In patients without ICG demarcation, delayed TAP might be helpful for predicting the high-risk patients with AL in the MF group; however, performing diverting stoma or strictly careful observation might be a realistic reaction.

Indications for neoadjuvant treatment based on risk factors for poor prognosis before and after neoadjuvant chemotherapy alone in patients with locally advanced rectal cancer

INTRODUCTION

The oncological benefit of neoadjuvant chemotherapy (NAC) alone for locally advanced rectal cancer (LARC) remains controversial. The aim of this study was to clarify the clinical risk factors for poor prognosis before and after NAC for decision making regarding additional treatment in patients with LARC.

MATERIALS AND METHODS

We examined a total of 96 patients with MRI-defined poor-risk locally advanced mid-low rectal cancer treated by NAC alone between 2006 and 2018. Survival outcomes and clinical risk factors for poor prognosis before and after NAC were analyzed.

RESULTS

In the median follow-up duration after surgery of 60 months (3-120), the rates of 5-year overall survival (OS), relapse-free survival (RFS), and local recurrence (LR) were 83.6%, 78.4%, and 8.2%, respectively. In the multivariate analyses, patients with cT4 disease had a significantly higher risk of poor OS (HR; 6.10, 95% CI; 1.32-28.15, P = 0.021) than those with cT3 disease. After NAC, ycN+ was significantly associated with a higher risk of poor OS (HR; 5.92, 95% CI; 1.27-27.62, P = 0.024) and RFS (HR; 2.55, 95% CI; 1.01-6.48, P = 0.048) than ycN-. In addition, patients with CEA after NAC (post-CEA) ≥ 5 ng/ml had a significantly higher risk LR (HR; 5.63, 95% CI; 1.06-29.93, P = 0.043).

CONCLUSION

NAC alone had an insufficient survival effect on patients with cT4 disease, ycN+, or an elevated post-CEA level. In contrast, NAC alone is a potential treatment for other patients with LARC.

What is the impact of systemic chemotherapy for lateral lymph nodes in patients with locally advanced low rectal cancer?

PURPOSE

Systemic chemotherapy (SC) before surgery is a potential treatment to improve survival in patients with advanced rectal cancer. However, the impact of SC on lateral lymph nodes (LLNs) remains unclear.

METHODS

A total of 78 patients with stage II/III low rectal cancer, who received 3-month oxaliplatin-based SC followed by LLN dissection (LLND) in principle, were analysed retrospectively. "Total lateral lymph node metastases (tLLNMs)" was defined as having either pathological LLNMs (pLLNMs) or lateral local recurrences (LLRs). Patients with the maximum short-axis size of LLNs ≥ 7 mm were classified into the swollen group (n = 21).

RESULTS

In the total cohort, tLLNMs included 6 pLLNMs (7.7%) and 2 LLRs (2.6%). In the non-swollen group, no patients had pLLNMs, but one had LLR (1.8%). In the swollen group, pLLNMs and LLRs were detected in 6 (28.6%) and 1 (4.8%), respectively. The swollen group was an independent risk factor for tLLNMs (P < 0.001), leading to the significantly worse 5-year relapse-free survival (RFS) of 52.4% than the others.

CONCLUSION

For patients without swollen LLNs, SC could allow for omission both of lateral irradiation and LLND. For patients with swollen LLNs, the lateral local control was favourable after SC and LLND without chemoradiotherapy (CRT); however, oxaliplatin-based SC might be insufficient to improve survival, requiring more intensive chemotherapy. CRT should be indicated according to the other risk factors of central local recurrence, although the swollen LLNs should be removed.

Beneficial effects of balloon pulmonary angioplasty on clinical outcomes in patients with residual pulmonary hypertension after pulmonary endarterectomy

Background

Although pulmonary endarterectomy (PEA) is an established surgical treatment for chronic thromboembolic pulmonary hypertension (CTEPH), a part of patients after PEA show residual pulmonary hypertension, leading to limited exercise capacity. Recently, several studies have indicated that balloon pulmonary angioplasty (BPA) improves hemodynamics, exercise capacity and prognosis in inoperable CTEPH patients. However, the effects of BPA in patients with residual pulmonary hypertension after PEA remain to be elucidated.

Aim

In the present study, we investigated comprehensive efficacy of BPA on hemodynamics, exercise capacity and right ventricular function in those with residual pulmonary hypertension after PEA.

Methods

From October 2010 to February 2019, 227 patients with CTEPH underwent PEA in our institution. Right heart catheterization after PEA (median follow up period from PEA to right heart catheterization 39 [10.5, 90] months) showed that 55 patients showed residual PH (mean pulmonary artery pressure (mPAP)≥25mmHg), and 38 of them referred to BPA (mean age 57 years old, male 8 (21%)) due to residual symptoms. In 29 out of 38 patients (76%) who completed BPA and underwent follow-up right heart catheterization, we examined hemodynamics, exercise capacity and right ventricular function before and after BPA. Follow-up examination was performed 3 months after last BPA session.

Results

In this study population (N=29), PEA significantly improved mPAP (47±7 to 38±10 mmHg), pulmonary vascular resistance (PVR, 14.6±4.6 to 9.2±4.6 WU) and right ventricular ejection fraction measured by magnetic resonance imaging (26.6±11.3 to 38.4±6.8%) (Figure). Median period from PEA to first BPA procedure was 42 [13.5, 94] months. Total session number during study period was 160 sessions, and mean session number of BPA was 5.5±1.5 per patient. Follow-up study revealed that BPA additionally improved mPAP (38±10 to 27±8 mmHg) and PVR (9.2±4.6 to 5.1±2.2 WU) (Figure). Similarly, 6-minute walk distance (393±125 to 452±125 m) and peak VO2 (16.4±3.8 to 18.1±4.6 ml/min/kg, p&lt;0.05) were increased, and WHO functional class also significantly improved by BPA (I/II/III/IV, 0/21/8/ 0 to 1/27/1/0, p&lt;0.01). In addition, right ventricular ejection fraction (38.4±6.8 to 44.2±7.1%) was increased after BPA (Figure). There were no procedure-related deaths and major lung injuries requiring oral intubation during study period. 3-year survival in patients after BPA was 100% (median follow-up period after last BPA session, 32 [18, 46] months).

Conclusion

In CTEPH patients with residual pulmonary hypertension after PEA, additional BPA significantly improved hemodynamics, right ventricular function, exercise capacity and residual symptoms without severe complications, leading to good prognosis. These results suggest that combination therapy of PEA and BPA could be an effective therapeutic option for post PEA patients with residual symptoms and exercise limitation.

Figure 1

Funding Acknowledgement

Type of funding source: None

Simultaneous pelvic exenteration and liver resection for primary rectal cancer with synchronous liver metastases: results from the PelvEx Collaborative

AIM

At presentation, 15-20% of patients with rectal cancer already have synchronous liver metastases. The aim of this study was to determine the surgical and survival outcomes in patients with advanced rectal cancer who underwent combined pelvic exenteration and liver (oligometastatic) resection.

METHOD

Data from 20 international institutions that performed simultaneous pelvic exenteration and liver resection between 2007 and 2017 were accumulated. Primarily, we examined perioperative outcomes, morbidity and mortality. We also assessed the impact that margin status had on survival.

RESULTS

Of 128 patients, 72 (56.2%) were men with a median age of 60 years [interquartile range (IQR) 15 years]. The median size of the liver oligometastatic deposits was 2 cm (IQR 1.8 cm). The median duration of surgery was 406 min (IQR 240 min), with a median blood loss of 1090 ml (IQR 2010 ml). A negative resection margin (R0 resection) was achieved in 73.5% of pelvic exenterations and 66.4% of liver resections. The 30-day mortality rate was 1.6%, and 32% of patients had a major postoperative complication. The 5-year overall survival for patients in whom an R0 resection of both primary and metastatic disease was achieved was 54.6% compared with 20% for those with an R1/R2 resection (P = 0.006).

CONCLUSION

Simultaneous pelvic exenteration and liver resection is feasible, with acceptable morbidity and mortality. Simultaneous resection should only be performed where an R0 resection of both pelvic and hepatic disease is anticipated.

The role of surgery for locally recurrent and second recurrent rectal cancer with metastatic disease

BACKGROUND

The role of surgery for locally recurrent rectal cancer (LRRC) with resectable distant metastases or second LRRC remains unclear. This study aimed to clarify the influence of synchronous distant metastases (SDMs), a history of distant metastasis resection (HDMR), and a second LRRC on the outcome.

METHODS

The long-term outcomes of 70 surgically treated patients with LRRC between 2006 and 2018 were compared by SDM (n = 10), HDMR (n = 17), and second LRRC (n = 7).

RESULTS

Among the 10 patients with SDM, 4 patients underwent simultaneous resection, whereas the other 6 underwent staged resection with distant first approach. Recurrence developed in 9 patients, of which 2 patients with liver re-resection achieved long-term survival without cancer. The patients with and without SDM had equivalent 5-year overall survival rate (40.5% vs. 53.3%, p = 0.519); however, patients with SDM had a worse 3-year recurrence-free survival rate than those without SDM (10.0% vs. 37.5%, p = 0.031). Multivariate analysis showed that primary non-sphincter-preserving surgery, second LRRC, and R1 resection were independent risk factors for overall survival. Similarly, primary non-sphincter-preserving surgery, second LRRC, SDM, and R1 resection were risk factors for recurrence-free survival.

CONCLUSIONS

Patients with SDM might still be suitable to undergo salvage surgery and achieve favourable overall survival. Distant metastasectomy should be performed first, followed by a sufficient interval to avoid unnecessary LRRC resection in uncurable patients. An HDMR should not be taken into consideration when making surgical plans. Surgical indication of second LRRC should be strict, especially in referred patients.

Abstract P5-01-03: Comparison of mammography findings between dense and non dense breast in Japanese subjects: The potential limitation of routine mammography

Introduction

Recently “Dense breast” has attracted numerous attention because of diagnostic difficulty in mammography among those harboring dense breast, which is far more frequent in Asian than Caucasian women. Therefore, in this study, we retrospectively evaluated the risks of subsequent development of malignancy through comparing the detailed mammographic characteristics between Japanese subjects harboring dense and non dense breasts.

Methods

We retrospectively examined mammorgraphic findings taken from March 2013 to March 2016 at Nahanishi Clinic, Okinawa, Japan. We stratified its density according to the suggestion of the Japan Central Organization on Quality Assurance of Breast Cancer Screening, which was defined by the proportion of fat area as follows; extremely high dense:10-20%, heterogeneously dense:40-50%, scattered fatty:70-90%, fatty: almost all the breast fat. “Dense breast” includes extremely high and heterogeneous dense. We evaluated the detailed radiological findings of each phenotypes including the characteristics of the mass, calcification and focal asymmetric density(FAD) and architectural distortion. We also compared the rates of subsequent cancer development and sensitivity of detecting cancer between those harboring dense and non dense breasts.

Results

We reviewed the mammography findings of 7747 Japanese women including 857 with breast cancers. When adjusted for age, the rate of dense breast was significantly associated with age, 88.6% in women in their 20s(vs40s p&lt;0.001 OR3.402), with incremental decrease, 80.4% in 30s(P&lt;0.001 OR1.802), 69.5% in 40s, 55.9% in 50s(P&lt;0.001 OR0.512), 32.3% in 60s(P&lt;0.001 OR 0.108), 19.5% in 70s(P&lt;0.001 OR 0.106) and 5.3% in over 80s(P&lt;0.001 OR0.024). The rate of malignancies was 9.1% (385) in dense and 13.6% (472) in non dense breasts. We then compared the mammographic findings between dense and non dense breast. Abnormal calcifications were detected more frequent(7.6%vs5.3% P&lt;0.001 OR1.478) but masses less so(16.4%vs23.7% P&lt;0.001 OR 0.632) in dense breast, while no significant differences detected in FADs(4.9%vs4.6% P=0.35 OR1.074) and distortions(1.2%vs1.4% P=0.29 OR=0.859) between dense and non dense breast. The rate of carcinoma was less frequent in dense breast among those associated with mammographic calcification(19%vs27.3% P&lt;0.01 OR0.626) but more frequently in dense breast among those with masses (13%vs19% P&lt;0.001 OR0.628). The rate of carcinoma was not different between dense and non dense breast in those with FADs (21.6vs20.6% P=0.72 OR1.067) and distortions(71.7%vs74.7% P=0.64 OR0.857). In addition, among 37 breast cancer patients who did not harbor the mammographic findings above (26 dense and 11 non dense breasts), the average mass length was significantly larger in dense (13.6mm) than non-dense breast (9.9mm) (P=0.018 used Welch's t test), respectively.

Conclusion

Results of our present study did demonstrate that detection of malignancy in those with mammographic dense breast is more difficult. Therefore, in those harboring dense breast in mammography, addition of other modalities such as US could improve the detection of breast carcinoma.

Citation Format: Takigami N, Tamaki K, Kamada Y, Uehara K, Terukina S, Ishida T, Miyashita M, McNamara KM, Tamaki N, Sasano H. Comparison of mammography findings between dense and non dense breast in Japanese subjects: The potential limitation of routine mammography [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-01-03.