Clinical feasibility of the preoperative CALLY index to predict short- and long-term outcomes of gastric cancer patients

BACKGROUND & AIMS

Gastric cancer (GC) is a major leading cause of cancer-related death worldwide. Systemic inflammation and the nutrition-based score are feasible prognostic markers for malignancies. Emerging evidence has also revealed the C-reactive protein -albumin-lymphocyte (CALLY) index to be a prognostic marker for several cancer types. However, its clinical significance to predict surgical and oncological outcomes of GC patients remains unclear.

METHODS

We assessed the preoperative CALLY index in 426 GC patients who received gastrectomy.

RESULTS

A low preoperative CALLY index was significantly correlated to all well-established clinicopathological factors for disease development, including an advanced T stage, the presence of venous invasion, lymphatic vessel invasion, lymph node metastasis, distant metastasis, and an advanced TNM stage. A low preoperative CALLY index was also an independent prognostic factor for overall survival [hazard ratio (HR): 2.64, 95% confidence interval (CI): 1.66-4.2; P<0.0001] and disease-free survival (HR: 1.76, 95% CI: 1.01-3.05; P=0.045). Additionally, a low preoperative CALLY index was an independent predictive factor for postoperative surgical site infection (odds ratio: 2.64, 95% CI: 1.42-4.89; P=0.002).

CONCLUSIONS

The preoperative CALLY index is valuable for perioperative and oncological management of GC patients.

Clinical implications of C-reactive protein-albumin-lymphocyte (CALLY) index in patients with esophageal cancer

PURPOSE

The C-reactive protein-albumin-lymphocyte (CALLY) index is a novel inflammatory nutritional biomarker. This study aimed to investigate the potential clinical significance and oncological prognostic role of the preoperative CALLY index in patients with esophageal cancer.

METHODS

We analyzed the preoperative CALLY index in 146 patients with esophageal cancer. The CALLY index and clinicopathological variables were analyzed by the Mann-Whitney U test, and associations between the CALLY index and survival outcomes were analyzed by Kaplan-Meier analysis and log-rank tests. Univariate and multivariate analyses of prognostic variables were conducted using Cox proportional hazards regression.

RESULTS

A lower preoperative CALLY index was significantly correlated with patient age, advanced T stage, presence of lymph node metastasis, neoadjuvant therapy, lymphatic invasion, and advanced stage classification. The preoperative CALLY index decreased significantly in a stage-dependent manner. Patients with esophageal cancer with a low CALLY index had poorer overall survival, disease-free survival than those with a high CALLY index. Multivariate analysis showed that a low CALLY index was an independent prognostic factor for overall survival, disease-free survival and an independent predictor of postoperative surgical site infection.

CONCLUSIONS

Preoperative CALLY index is a useful marker to guide the perioperative and postoperative management of patients with esophageal cancer.

Promoter methylation levels of microRNA-124 in non-neoplastic rectal mucosa as a potential biomarker for ulcerative colitis-associated colorectal cancer in pediatric-onset patients

PURPOSE

To determine the methylation level of the miR-124 promoter in non-neoplastic rectal mucosa of patients with pediatric-onset ulcerative colitis (UC) to predict UC-associated colorectal cancer (UC-CRC).

METHODS

Between 2005 and 2017, non-neoplastic rectal tissue specimens were collected from 86 patients with UC, including 13 patients with UC-CRC; cancer tissues were obtained from the latter group. The methylation status of the miR-124 promoter was quantified using bisulfite pyrosequencing and compared between pediatric- and adult-onset UC patients.

RESULTS

Patients with pediatric-onset UC experienced a significantly shorter disease duration than those with adult-onset UC. The levels of miR-124 promoter methylation in non-neoplastic rectal mucosa were positively correlated with the age at the diagnosis and duration of UC. The rate of increase in miR-124 methylation was accelerated in patients with pediatric-onset UC compared to those with adult-onset UC. Furthermore, the miR-124 methylation levels in non-neoplastic rectal mucosa were significantly higher in patients with UC-CRC than in those with UC alone (P = 0.02). A receiver operating characteristic analysis revealed that miR-124 methylation in non-neoplastic tissue discriminated between patients with pediatric-onset UC with or without CRC.

CONCLUSION

miR-124 methylation in non-neoplastic rectal mucosa may be a useful biomarker for identifying patients with pediatric-onset UC who face the highest risk of developing UC-CRC.

Prediction of Post-Gastrectomy Pancreatic Complications: A Preoperative Imaging Study Based on Computed Tomography

BACKGROUND

Postoperative pancreas-related complications (PPRCs) are common after laparoscopic gastrectomy (LG) in patients with gastric cancer. We estimated the anatomical location of the pancreas on a computed tomography (CT) image and investigated its impact on the incidence of PPRCs after LG.

METHODS

We retrospectively reviewed the preoperative CT images of 203 patients who underwent LG for gastric cancer between January 2010 and December 2017. From these images, we measured the gap between the upper edge of the pancreatic body and the root of the common hepatic artery. We evaluated the potential relationship between PPRCs and the gap between pancreas and common hepatic artery (GPC) status using an analysis based on the median cutoff value and assessed the impact of GPC status on PPRC incidence. We performed univariate and multivariate analyses to identify predictive factors for PPRC.

RESULT

Postoperative pancreas-related complications occurred in 11 patients (5.4%). The median of the optimal cutoff GPC value for predicting PPRC was 0 mm; therefore, we classified the GPC status into two groups: GPC plus group and GPC minus group. Univariate analysis revealed that sex (male), C-reactive protein (CRP) > .07 mg/dl, GPC plus, and visceral fat area (VFA) > 99 cm2 were associated with the development of PPRC. Multivariate analysis identified only GPC plus as independent predictor of PPRC (hazard ratio: 4.60 [95% confidence interval 1.11-31.15], P = .034).

CONCLUSION

The GPC is a simple and reliable predictor of PPRC after LG. Surgeons should evaluate GPC status on preoperative CT images before proceeding with laparoscopic gastric cancer surgery.

Clinical significance of the preoperative inflammatory burden index in esophageal cancer

INTRODUCTION

The inflammatory burden index (IBI) serves as a prognostic marker for several cancers. Here, we evaluated the predictive value of preoperative IBI associated with the surgical and oncological outcomes of patients with esophageal cancer (EC).

METHODS

The IBI was formulated as C-reaction protein x neutrophil/lymphocyte. We retrospectively analyzed preoperative IBI of 147 EC patients receiving esophagectomy between 2008 and 2018. Cox proportional hazards models and multivariable logistic regression were employed to identify independent risk factors of surgical site infection and prognosis.

RESULTS

Increased preoperative IBI significantly correlated with higher tumor stage. Patients with high IBI experienced shorter overall survival (P = 0.0002) and disease-free survival (P = 0.002) compared with those with low IBI. In the adjusted Cox-proportional hazards regression models, increased IBI served as an independent prognostic factor for overall survival (hazard ratio, 3.56; 95% confidence interval, 1.79-7.34; P = 0.0003) and disease-free survival (hazard ratio, 3.03; 95% confidence interval, 1.60-5.92; P = 0.007). Multivariable analysis identified preoperative high IBI served as an independent risk factor for overall surgical site infection (odds ratio, 2.53; 95% confidence interval, 1.00-6.38; P = 0.049).

CONCLUSION

Preoperative IBI may serve as a useful predictor of prognosis and surgical site infection of patients with EC after esophagectomy.

[A Case Report of Organ Preservation by Total Neoadjuvant Therapy and Local Excision for Lower Rectal Cancer]

In our department, total neoadjuvant therapy(TNT), which is a combination of preoperative chemotherapy and preoperative chemoradiotherapy(nCRT), has been introduced for the purpose of local and systemic disease control for lower rectal cancer. For patients in whom a clinical complete response(cCR)was obtained by TNT, we avoid the surgery and preserve organs, and follow-up strictly under the informed consent(watch and wait). In addition, for patients with remarkably reduced primary lesions(near cCR)without lymphadenopathy after TNT, the option of omitting total mesorectal excision (TME)and performing organ preservation by local excision can be introduced. Here, we report a case in which near cCR was obtained by TNT and organ preservation was performed by local excision. A 67-year-old man with lower rectal cancer(AV 5 cm, 15 mm, type 2, cT2N0M0, cStage Ⅰ)was referred to our department with a desire to preserve the anus. TNT with nCRT→CAPOX was performed, and near cCR was obtained. After that, full thickness local excision of the residual disease was performed by transanal minimally invasive surgery(TAMIS). The final pathological diagnosis was Rb, 0.7 mm, por2, ypT1a, ypPM0, ypDM0, ypRM0. No recurrence is recognized for 3 years and 10 months after the operation.

Robot-assisted laparoscopic abdominoperineal resection for anal canal cancer associated with Crohn's disease: A case report

A 37-year-old man with Crohn's disease (CD) and a history of abdominal surgery was diagnosed with anal canal cancer. Robot-assisted laparoscopic abdominoperineal resection was performed and the patient was discharged without any postoperative complications. Recently, minimally invasive surgery for CD patients has grown in popularity. However, there have been few studies of robotic surgery for CD patients with anal canal cancer. To the best of our knowledge, we present the first report of a patient with CD-associated anal canal cancer who underwent robot-assisted laparoscopic abdominoperineal resection.

Double inferior vena cava, an uncommon but relevant anatomical anomaly in surgery for lower rectal cancer: a report of two cases

BACKGROUND

Double inferior vena cava (DIVC) is rare and usually detected incidentally. DIVC may be associated with several anatomical variants of the retroperitoneal and pelvic veins. These variants can pose a clinical problem during colorectal surgery. We present two patients with lower rectal cancer who also had a DIVC.

CASE PRESENTATION

Case 1 was a 72-year-old man with advanced lower rectal cancer (T3N0M0) who underwent robot-assisted low anterior resection after neoadjuvant therapy. A DIVC was detected on preoperative computed tomography (CT). During the operation, a presacral vein was injured while mobilizing the rectum and hemostasis could not be achieved. We converted to open surgery and packed the pelvic cavity for hemostasis. Retrospective analysis suggested the injured vein arose from an interiliac vein of the presacral pelvic venous plexus. Case 2 was a 50-year-old woman with lower rectal cancer (T3N0M0), immune thrombocytopenic purpura, and a DIVC. Although preoperative three-dimensional CT angiography showed no obvious pelvic vein abnormalities, a short course of preoperative radiotherapy was delivered to avoid lateral pelvic lymph node dissection. Chemotherapy was deferred owing to her thrombocytopenic disease. Laparoscopic abdominoperineal resection was performed meticulously to minimize bleeding and achieve rapid hemostasis. No intraoperative complications occurred.

CONCLUSION

DIVC is often accompanied by venous malformations that may pose a problem when mobilizing the mesorectum from the retroperitoneum. Preoperative assessment of pelvic vessel anatomy using three-dimensional CT is essential in patients with a DIVC who undergo rectal surgery.

Extraction of a metallic susceptor after accidental ingestion of the heated tobaccostick TEREA™: a case report

BACKGROUND

Tobacco ingestion is widely known to cause nicotine toxicity, which may result in severe symptoms. Two heated tobacco sticks, called TEREA™ and SENTIA™, were launched in 2021 by Philip Morris International (New York, NY, USA), and their ingestion is associated with a risk of bowel injury because they contain a partially pointed metallic susceptor. However, this risk is not well known to the general public or healthcare providers. To increase awareness of this risk, we herein report a case involving extraction of a metallic susceptor after ingestion of the heated tobacco stick TEREA™.

CASE PRESENTATION

A 7-month-old girl presented to the emergency department of a nearby hospital because she was suspected to have accidentally swallowed heated tobacco. Although she presented with no symptoms related to nicotine poisoning, abdominal X-ray examination revealed a metal object in her stomach. According to a statement released by the Japan Poison Information Center, the TEREA™ heated tobacco stick contains a metallic susceptor with a rectangular shape and sharp corners. The patient was transferred to our department because of the risk of bowel injury, and upper gastrointestinal endoscopy was performed. No cigarettes were found by endoscopic observation; however, a metallic susceptor was located in the second part of the duodenum. We grasped it with biopsy forceps and carefully removed it using an endoscope with a cap attached to the tip. The post-endoscopic course was uneventful.

CONCLUSIONS

Some patients who ingest heated tobacco sticks might be exposed not only to the effects of nicotine but also to physical damage caused by a metallic susceptor. Infants and toddlers especially could swallow these sticks, therefore tobacco companies need to make the problem more public. Clinicians also should alert the problem, and pay attention to this risk in the clinical setting.

[Stage Ⅳ Gastric Cancer with Long Term Survival by Conversion Surgery-A Case Report]

A 78-year-old man presenting with a chief complaint of discomfort was found to have advanced gastric cancer invading pancreatic body, and with the metastasis of paraaortic lymph node(No. 16). After 3 courses of the S-1 plus oxaliplatin regimen, CT scan showed the disappearance of invasion to pancreatic body, and the No. 16 lymph node. Then total gastrectomy(D2+No. 19+No. 16a1+No. 16a2), Roux-en-Y reconstruction and cholecystectomy were undergoing. Histological assessment for treatment response showed Grade 1a, and we finally diagnosed gastric cancer: MU, Post, type 2, 30×20 mm, tub1>por1, ypT3, ypN1, ycM0, ypStage ⅡB. The postoperative course was uneventful, and the patient was discharged from the hospital on postoperative day 19. S-1 as adjuvant chemotherapy was performed for 12 months, and no recurrence was recognized for 5 years and 9 months after operation.

Prognostic potential of METTL3 expression in patients with gastric cancer

Methyltransferase-like 3 (METTL3) is a crucial component of the m6A methyltransferase complex, which serves pivotal roles in tumor progression. The present study investigated the prognostic significance of METTL3 expression in gastric cancer (GC). The expression levels of METTL3 were assessed by immunohistochemistry in formalin-fixed paraffin-embedded (FFPE) tissue specimens from 158 patients with GC. Propensity score matching (PSM) analysis was performed to clarify its prognostic potential. METTL3 gene expression was also investigated in fresh frozen specimens from another independent cohort of 57 patients with GC to establish its clinical relevance. Knockdown of METTL3 by small interfering RNA transfection was performed to evaluate its function in vitro. METTL3 expression was significantly higher in cancerous tissues compared with in corresponding normal mucosa (P<0.0001), and high METTL3 expression was an independent prognostic factor for overall and disease-free survival in the FFPE cohort of patients with GC. PSM analysis revealed that elevated METTL3 expression was significantly associated with poor survival outcomes, which was subsequently validated in another cohort of fresh frozen specimens. Knockdown of METTL3 inhibited proliferation, invasion, migration and anoikis resistance in GC cells. In conclusion, METTL3 expression may be used as a clinically feasible prognostic marker and could serve as a potential therapeutic target in patients with GC.

Prognostic significance of CD8+ tumor‑infiltrating lymphocytes and CD66b+ tumor‑associated neutrophils in the invasive margins of stages I‑III colorectal cancer

Tumor-infiltrating immune cells play an essential role in cancer progression and may help supplement the Tumor, Node, Metastasis (TNM) classification for cancer prognosis. Currently, there are numerous conflicting reports discussing the significance of tumor-associated neutrophils (TANs) in colorectal cancer (CRC). In particular, the role of TANs in the invasive margin is unclear. The present study investigated the prognostic significance of CD66⁺ TANs and CD8⁺ tumor-infiltrating lymphocytes (TILs) in the invasive margin of 103 patients with CRC. By using immunohistochemistry, survival analysis was performed on CD8⁺ TILs and CD66⁺ TANs individually, as well as models including TILs and TANs simultaneously. The findings indicated that the densities of CD8⁺ TILs and CD66b⁺ TANs in the invasive margin may provide significant prognostic value for predicting survival. Moreover, the combined evaluation of CD8⁺ TILs and CD66b⁺ TANs in the invasive margin could further improve the validity for the prediction of oncological outcomes. In addition, multivariate analysis revealed that simultaneous low tumor infiltration by CD8⁺ TILs and CD66b⁺ was an independent predictive factor for overall survival (HR=4.17, 95% CI, 1.55-12.5; P=0.004) and disease-free survival (HR=2.75, 95% CI, 1.27-6.12; P=0.01). Given the importance of CD8⁺ TILs and CD66b⁺ TANs in the tumor microenvironment, the assessment of their densities in the invasive margin may serve as a valuable prognostic marker for CRC.

[The Watch and Wait Strategy for Lower Rectal Cancer Patients Who Achieved Clinical Complete Response after Chemotherapy to Treat Inguinal Lymph Node Metastasis following Total Neoadjuvant Therapy-A Case Report]

The watch and wait strategy(W&W)is optional non-operative management for lower advanced rectal cancer patients who have achieved clinical complete response(cCR)following neoadjuvant treatment. However, the clinical implication of surgical intervention for the primary lesion is not well elucidated when distant metastasis appears with complete remission of the primary lesion. We report a case of a 47-year-old-woman with lower rectal cancer presenting inguinal lymph node metastasis after total neoadjuvant therapy(TNT)and managed through W&W after achieving cCR following chemotherapy. TNT was performed as a preoperative treatment for lower advanced rectal cancer, cT3N2aM0, cStage Ⅲb. Although the primary lesion and mesenteric lymph node metastasis completely disappeared, bilateral inguinal lymph node metastasis appeared immediately after TNT. The patient was treated with FOLFOX plus panitumumab for rectal cancer with RAS and BRAF wild-type. Four months after chemotherapy, the inguinal lymph node metastasis disappeared, and W&W was used for the management. She stayed alive without recurrence 1 year and 9 months after chemotherapy.

Cumulative C-reactive Protein in the Perioperative Period as a Novel Marker for Oncological Outcome in Patients with Colorectal Cancer Undergoing Curative Resection

Objectives:

Systemic inflammatory response is strongly associated with poor oncological outcome in colorectal cancer (CRC). Perioperative inflammation caused by surgical stress can lead to the development of postoperative infectious complications (PIC) as well as cancer-related inflammation. We aimed to evaluate the prognostic potential of perioperative systemic inflammation by calculating the time-dependent cumulative C-reactive protein (CRP) levels during the perioperative period.

Methods:

We analyzed clinicopathological data from 540 patients with CRC who underwent potentially curative surgery at our institution. The time-dependent aggregated CRP level was denoted “cumulative CRP,” which represents the area under the line of time (days) and the CRP levels preoperatively and on postoperative days 1, 3, and 7.

Results:

Cumulative CRP was significantly higher in patients with CRC undergoing open surgery than in patients undergoing laparoscopic surgery. In multivariate analysis, high cumulative CRP was an independent prognostic factor for disease-free survival (DFS) and overall survival (OS) in both the laparoscopic and open surgery groups. Patients with CRC and high cumulative CRP had significantly poorer DFS and OS than those with low cumulative CRP, including those patients without PIC.

Conclusions:

Cumulative CRP is an independent predictive marker of OS and DFS in patients with CRC who undergo curative surgery.

Abstract 653: Clinical value and oncogenic role of METTL3 expression in gastric cancer patients

Background: Gastric cancer (GC) is one of the most common cancers and leading cause of cancer-related deaths worldwide, primarily because of rapid disease progression to advanced stages and highly malignant potential. Methyltransferase-like 3 (METTL3) is a crucial component of the m6A methyltransferase complex, and plays pivotal roles in tumour progression. This study investigated the prognostic significance of METTL3 expression in gastric cancer (GC).

Methods: We assessed expression levels of METTL3 by immunohistochemistry in formalin-fixed paraffin-embedded (FFPE) tissue specimens from one hundred fifty-eight GC patients. Propensity score matching (PSM) analysis was performed to clarify its prognostic potential. The METTL3 gene expression was also investigated in fresh frozen specimens from another independent cohort of fifty-seven GC patients to establish its clinical relevance. Knockdown of METTL3 by siRNA transfection was performed to evaluate its function in vitro.

Results: METTL3 expression was significantly higher in cancerous tissues vs. corresponding normal mucosa (P&lt;0.0001), and high METTL3 staining group was significantly associated with males (P=0.029), an advanced T stage (P=0.0002), the presence of venous invasion (P&lt;0.0001), lymphatic vessel invasion (P=0.011), lymph node metastasis (P=0.004), distant metastasis (P=0.0004), and advanced TNM stage classification (P=0.0001) in the FFPE cohort of GC patients. Survival curve analysis showed that patients with increased expression of METTL3 showed poorer prognosis in terms of both overall survival (OS: P&lt;0.0001, log-rank test) and disease-free survival (DFS: P=0.0005, log-rank test) compared to those with low expression. Multivariate analysis revealed that increased expression of METTL3 was an independent prognostic factor for overall survival (OS: hazard ratio (HR), 3.24; 95% confidence interval (CI), 1.57-6.68; p=0.001) and disease-free survival (DFS: HR, 2.4; 95% CI, 1.12-5.16; p=0.025) in the FFPE cohort of GC patients. PSM analysis revealed that elevated METTL3 expression was significantly associated with poor survival outcomes (OS: P=0.05; DFS: P=0.038; log-rank test), which was subsequently validated in another cohort of fresh frozen specimens (OS: p=0.007; DFS: p=0.029; log-rank test). The knockdown of METTL3 inhibited proliferation, invasion, migration, and anoikis resistance in GC cells.

Conclusion: METTL3 expression may be used as a clinically feasible prognostic marker and could serve as a potential therapeutic target in GC patients.

Citation Format: Yoshinaga Okugawa, Yuji Toiyama, Chengzeng Yin, Ma Ruiya, Akul Goel, Takashi Ichikawa, Hiroki Imaoka, Takahito Kitajima, Tadanobu Shimura, Mikio Kawamura, Hiromi Yasuda, Hiroyuki Fujikawa, Takeshi Yokoe, Ikuyo Mochiki, Masaki Ohi, Kaname Nakatani. Clinical value and oncogenic role of METTL3 expression in gastric cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 653.

Antitumor effects of Andrographis via ferroptosis-associated genes in gastric cancer

The overall prognosis of advanced/metastatic gastric cancer (GC) remains poor despite the development of pharmacotherapy. Therefore, other treatment options, such as complementary and alternative medicine, should be considered to overcome this aggressive malignancy. Andrographis, which is a generally unharmful botanical compound, has gained increasing interest for its anticancer effects in multiple malignancies via the regulation of cancer progression-associated signaling pathways. In the present study, a series of in vitro experiments (cell proliferation, colony formation and apoptosis assays) was designed to elucidate the antitumor potential and mechanism of Andrographis in GC cells. The present study demonstrated that Andrographis exerted antitumor effects in GC cell lines (MKN74 and NUGC4) by inhibiting proliferation, reducing colony formation and enhancing apoptotic activity. Furthermore, it was demonstrated that the expression levels of the ferroptosis-associated genes heme oxygenase-1, glutamate-cysteine ligase catalytic and glutamate-cysteine ligase modifier were significantly upregulated after Andrographis treatment in both GC cell lines in reverse transcription-quantitative PCR experiments (P<0.05); this finding was further confirmed by immunoblotting assays (P<0.05). In conclusion, to the best of our knowledge, the present study was the first to demonstrate that Andrographis possessed antitumor properties by altering the expression levels of ferroptosis-associated genes, thereby providing novel insights into the potential of Andrographis as an adjunctive treatment option for patients with metastatic GC.

Modified intramuscular adipose tissue content as a feasible surrogate marker for malnutrition in gastrointestinal cancer

BACKGROUND & AIMS

Myosteatosis is gathering attention as a feasible indicator for sarcopenia and increased risk of morbidity. However, the prognostic value of intramuscular adipose tissue content (IMAC) as an assessment method for myosteatosis remains controversial. The objectives of this study are to compare the prognostic value of intramuscular adipose tissue content (IMAC) with our newly-developed modified IMAC (mIMAC), and to assess the clinical significance of mIMAC in colorectal cancer (CRC) and gastric cancer (GC).

METHODS

We evaluated 892 patients with CRC or GC, and assessed preoperative IMAC and mIMAC to compare their prognostic and predictive values for postoperative infectious complications in both cohorts.

RESULTS

Both preoperative IMAC and mIMAC were sex- and disease-dependent, and positively or negatively correlated with age in CRC and GC patients (IMAC: CRC: r = 0.33, P < 0.0001; GC: r = 0.304, P < 0.0001; mIMAC: CRC: r = -0.364, P < 0.0001; GC: r = -0.263, P < 0.0001). In contrast to IMAC, lower preoperative mIMAC was significantly associated with disease-development factors, and was an independent prognostic factor for both overall survival (OS) and disease-free survival (DFS) in both CRC (OS: hazard ratio (HR): 1.95, 95% confidence interval (CI): 1.25-3.03, p = 0.003; DFS: HR: 1.93, 95% CI: 1.22-3.04, p = 0.005) and GC patients (OS: HR: 2.11, 95% CI: 1.22-3.68, P = 0.008; DFS: HR: 2.03, 95% CI: 1.18-3.5, P = 0.011). Patients with postoperative remote infections had a poorer prognosis compared with those without in both cohorts (CRC: HR: 2.67, 95% CI: 1.46-4.89, P = 0.002; GC: HR: 3.01, 95% CI: 1.47-6.19, P = 0.003), and low mIMAC was an independent risk factor for postoperative remote infection in both cancers (CRC: odds ratio (OR): 2.56, 95% CI: 1.06-6.23, P = 0.038; GC: OR: 2.8, 95% CI: 1.03-7.58, P = 0.043). Finally, we assessed the correlation between IMAC or mIMAC and the representative frailty markers body mass index (BMI), serum albumin, and prognostic nutritional index (PNI). We found a positive correlation between preoperative mIMAC and all of these markers in both cohorts (CRC: BMI: r = 0.193, P < 0.0001; serum albumin: r = 0.42, P < 0.0001; PNI: r = 0.39, P < 0.0001; GC: BMI: r = 0.22, P < 0.0001; serum albumin: r = 0.212, P < 0.0001; PNI: r = 0.287, P < 0.0001).

CONCLUSIONS

Preoperative mIMAC could be useful for perioperative and postoperative management in CRC and GC.

Geriatric nutritional risk index predicts cancer prognosis in patients with local advanced rectal cancer undergoing chemoradiotherapy followed by curative surgery

Aim

The clinical significance of the geriatric nutritional risk index (GNRI) in locally advanced rectal cancer (LARC) patients undergoing preoperative chemoradiotherapy (CRT) followed by curative surgery has not been comprehensively evaluated.

Methods

This retrospective study enrolled 93 LARC patients diagnosed with clinical lymph node metastasis. The GNRI formula was as follows: 1.489 × albumin (g/l) + 41.7 × current weight/ideal weight. Patients were categorized as GNRI low (GNRI < 104.25) or high (GNRI > 104.25) according to the receiver operating characteristic (ROC) curve for survival analysis. The impact of GNRI status on the prognostic outcomes of curative surgery for LARC was examined.

Results

There were 55 (59.14%) and 38 (40.86%) patients in the GNRI high and low groups, respectively. Of the investigated demographic factors, age, pathological tumor invasion, and presence of recurrence were significantly associated with the GNRI value. In Kaplan–Meier analysis, overall survival (OS) and disease-free survival (DFS) were significantly shorter in the GNRI low group (OS: p = 0.00020, DFS: p = 0.0044, log-rank test). Multivariate analysis using a Cox proportional hazards model showed that a low GNRI was an independent risk factor for poor OS (hazard ratio (HR) = 3.22; 95% confidence interval (CI), 1.37–8.23; p = 0.0068) and DFS (HR = 2.32; 95%CI = 1.15–4.79; p = 0.018). Although use of adjuvant therapy has no impact on prognosis (OS: p = 0.26, DFS: p = 0.29), low GNRI showed shorter OS and DFS in patients with pathological lymph node metastasis [ypN(+)] (OS: p = 0.033, DFS: p = 0.032, log-rank test).

Conclusions

GNRI is a useful marker for LARC patients diagnosed with clinical lymph node metastasis and treated by preoperative CRT followed by curative surgery. GNRI is a useful tool to identify high risk of recurrence for improving the survival in LARC patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-021-02139-z.

Fusobacterium nucleatum infection correlates with two types of microsatellite alterations in colorectal cancer and triggers DNA damage

Fusobacterium nucleatum (Fn) is frequently found in colorectal cancers (CRCs). High loads of Fn DNA are detected in CRC tissues with microsatellite instability-high (MSI-H), or with the CpG island hypermethylation phenotype (CIMP). Fn infection is also associated with the inflammatory tumor microenvironment of CRC. A subtype of CRC exhibits inflammation-associated microsatellite alterations (IAMA), which are characterized by microsatellite instability-low (MSI-L) and/or an elevated level of microsatellite alterations at selected tetra-nucleotide repeats (EMAST). Here we describe two independent CRC cohorts in which heavy or moderate loads of Fn DNA are associated with MSI-H and L/E CRC respectively. We also show evidence that Fn produces factors that induce γ-H2AX, a hallmark of DNA double strand breaks (DSBs), in the infected cells.

The relationship between preoperative T helper cytokines in the ileal mucosa and the pathogenesis of pouchitis

Background

Although the etiology of pouchitis remains unknown, inflammatory cytokines are significantly associated with the pathogenesis of pouchitis. The cytokine responses that characterize inflammatory bowel diseases (IBD) are key pathogenic components of the disease. Although cytokine profiles in the colonic mucosa have been investigated in experimental colitis models or IBD patients, cytokine profiles in the ileal mucosa at colectomy have been rarely assessed.

Aim

To assess the relationship between pouchitis and T helper (Th) cytokines in the ileal mucosa collected at the time of colectomy and pouch construction.

Methods

This retrospective study involved 68 consecutive patients from January 2004 to May 2011 who underwent ileal pouch–anal anastomosis for ulcerative colitis. Samples were obtained from the terminal ileum of resected specimens at time of total colectomy or subtotal colectomy. mRNA expression levels of Th cytokines (IFN-γ, IL-23A, IL-5, IL-13 and IL-17A) were determined.

Results

Forty of 68 patients (58.8%) developed pouchitis. There was no association between IL-23A expression levels and incidence of pouchitis (p = 0.301). Patients with elevated IFN-γ had a significantly higher incidence of pouchitis compared with low IFN-γ patients (p = 0.043). Univariate analysis demonstrated a total dose of prednisolone > 7000 mg administered before colectomy (p = 0.04) and high IFN-γ expression (p = 0.02) were significant risk factors for pouchitis onset. In multivariate analysis, elevated IFN-γ messenger(m)RNA levels were significantly associated with pouchitis onset (p = 0.03).

Conclusion

IFN-γ expression in the normal ileal mucosa at the time of colectomy may be an important factor in the pathophysiology of pouchitis.

Lymphocyte-C-reactive Protein Ratio as Promising New Marker for Predicting Surgical and Oncological Outcomes in Colorectal Cancer

BACKGROUND

Systemic inflammation via host-tumor interactions is currently recognized as a hallmark of cancer. The aim of this study was to evaluate the prognostic value of various combinations of inflammatory factors using preoperative blood, and to assess the clinical significance of our newly developed inflammatory score in colorectal cancer (CRC) patients.

METHOD

In total 477 CRC patients from the discovery and validation cohorts were enrolled in this study. We assessed the predictive impact for recurrence using a combination of nine inflammatory markers in the discovery set, and focused on lymphocyte-C-reactive protein ratio (LCR) to elucidate its prognostic and predictive value for peri-operative risk in both cohorts.

RESULTS

A combination of lymphocytic count along with C-reactive protein levels demonstrated the highest correlation with recurrence compared with other parameters in CRC patients. Lower levels of preoperative LCR significantly correlated with undifferentiated histology, advanced T stage, presence of lymph node metastasis, distant metastasis, and advanced stage classification. Decreased preoperative LCR (using an optimal cut-off threshold of 6000) was an independent prognostic factor for both disease-free survival and overall survival, and emerged as an independent risk factor for postoperative complications and surgical-site infections in CRC patients. Finally, we assessed the clinical feasibility of LCR in an independent validation cohort, and confirmed that decreased preoperative LCR was an independent prognostic factor for both disease-free survival and overall survival, and was an independent predictor for postoperative complications and surgical-site infections in CRC patients.

CONCLUSION

Preoperative LCR is a useful marker for perioperative and postoperative management of CRC patients.

0746 Dynamics of Sleep Stage Transitions in Patients with Narcolepsy and Other Hypersomnias

Introduction

Narcolepsy is a chronic sleep disorder characterized by excessive daytime sleepiness and abnormal REM sleep phenomena. Narcolepsy can be distinguished into type 1 (NT1; with cataplexy) and type 2 (NT2; without cataplexy). It has been reported that sleep stage sequences at sleep-onset as well as sleep-wake dynamics across the night may be useful in the differential diagnosis of hypersomnia. Here we studied dynamic features of sleep stage transitions during whole night sleep in patients with NT1, NT2, and other types of hypersomnia (o-HS).

Methods

Twenty patients with NT1, 14 patients with NT2, and 35 patients with o-HS underwent overnight PSG. Transition probabilities between sleep stages (wake, N1, N2, N3, and REM) and survival curves of continuous runs of each sleep stage were compared between groups. Transition-specific survival curves of continuous runs of each sleep stage, dependent on the subsequent stage of the transition, were also compared.

Results

The probability of transitions from N1-to-wake was significantly greater in NT1 than in NT2 and o-HS while that from N1-to-N2 was significantly smaller in NT1 than in NT2 and o-HS. The probability of transitions from N2-to-REM was significantly smaller in NT1 than in o-HS. Wake and N1 were significantly more continuous in NT1 than in NT2; specifically, N1 followed by N2 was significantly more continuous in NT1 than in NT2 and o-HS. N2 was significantly less continuous in NT1 and NT2 than in o-HS; this was specifically confirmed for N2 followed by N1/wake. REM sleep was significantly less continuous in NT1 than in NT2 and o-HS; specifically, REM sleep followed by wake was significantly less continuous in NT1 than in o-HS. Continuity of N3 did not differ significantly between groups.

Conclusion

Dynamics of sleep stage transitions differed between NT1, NT2, and o-HS. Dynamic features of sleep such as sleep instability, persistency of wake/N1, and REM fragmentation may differentiate NT1 from NT2, while N2 continuity may differentiate narcolepsy from o-HS. The results suggest that sleep transition analysis may be of clinical utility and provide insights into the underlying pathophysiology of hypersomnia and narcolepsy.

Support

JSPS KAKENHI (18K17891 to AK).

Billroth-I Reconstruction with Overlap Anastomosis Using an EndoWrist Linear Stapler After Robotic Distal Gastrectomy

Introduction: Robotic distal gastrectomy (RDG) is now thought to be less invasive than conventional laparoscopic distal gastrectomy (LDG) for gastric cancer. Although the delta-shaped anastomosis is an established, widely performed procedure for intracorporeal Billroth-I (B-I) gastroduodenostomy after LDG, it has some difficulties and is performed in the ischemic region of the duodenum. We therefore developed a novel overlap B-I gastroduodenostomy after RDG. Materials and Methods: We started using the da Vinci Surgical System (Intuitive Surgical, Sunnyvale, CA) for RDG in May 2017. The robotic overlap B-I reconstruction was performed via side-to-side anastomosis, as follows: Two small incisions were made, one on the greater curvature of the remnant stomach, 5 cm from the edge of the remnant gastric stump, and one on the superior edge of the anterior wall of the duodenal stump. A 45-mm EndoWrist linear stapler device (EWLS) loaded with a blue cartridge was inserted through the incision. After the remnant stomach and duodenum were attached to the V-shaped form by the EWLS, the incisions were closed by the EWLS. Results: Seven patients underwent RDG followed by a robotic overlap B-I procedure up to March 2019. Short-term outcomes were determined from medical records and operative videos. No intraoperative complications or conversions to open or conventional laparoscopic surgery occurred. The mean time for the anastomosis was 37 (range 29-45 minutes) minutes. No postoperative complications occurred following the robotic overlap B-I procedure. Discussion: RDG followed by an overlap B-I gastroduodenostomy might be feasible and safe. However, long-term follow-up is required to identify additional benefits.

Clinical significance of an increased red blood cell distribution width in patients with rectal cancer undergoing chemoradiotherapy followed by surgery

PURPOSE

The clinical significance of the red blood cell distribution width (RDW) in patients with rectal cancer undergoing preoperative chemoradiotherapy (CRT) followed by surgery has not been fully evaluated.

METHODS

In this retrospective study, we investigated the association between the RDW and the prognosis in 120 patients with locally advanced rectal cancer (LARC). We also performed a subgroup analysis limited to patients with pathological TNM stage I-II (ypN[-]) LARC.

RESULTS

The RDW standard deviation was used to evaluate the RDW. We set 47.1% as the cut-off value of the RDW for the assessment of the prognosis. The RDW exhibited a significant negative relationship with the serum hemoglobin and albumin levels. An elevated RDW was an independent prognostic factor for the overall survival (OS) and disease-free survival (DFS) in patients with LARC. In addition, an elevated RDW predicted a poor OS and DFS in patients with pathological TNM stage I-II (ypN[-]) LARC.

CONCLUSIONS

The RDW is a promising predictor of a poor survival and recurrence in patients with LARC treated by CRT.

Modified neutrophil-platelet score as a promising marker for stratified surgical and oncological outcomes of patients with gastric cancer

PURPOSE

Gastric cancer (GC) is a common malignancy, especially in East Asian countries. There is emerging evidence that circulating neutrophil and platelet levels correlate with cancer progression. We evaluated the short- and long-term outcomes of GC patients systemically, to compare the original neutrophil-platelet score (NPS) and our modified NPS (mNPS).

METHODS

We analyzed the original pre-operative NPS and the mNPS of 621 GC patients.

RESULTS

Racial differences between the United Kingdom and East Asian countries accounted for compelling deviation in classification using the original NPS, which could not reliably stratify the prognoses of Japanese GC patients. We developed the mNPS using appropriate cutoff levels for pre-operative neutrophils and platelets, and demonstrated that the pre-operative mNPS was significantly correlated with all of the well-established clinicopathological factors for disease development, including advanced T stage, venous and lymphatic vessel invasion, lymph node/peritoneal /distant metastasis, and tumor-node-metastasis stage. The pre-operative mNPS could stratify prognostication for both overall survival (OS) and disease-free survival (DFS): a high pre-operative mNPS was an independent prognostic factor for the OS and DFS of GC patients and also an independent predictor of post-operative surgical site infection after gastrectomy.

CONCLUSION

Calculating the mNPS could help clinicians to stratify the surgical and oncological risks of patients with GC.

Crohn's-Like Lymphoid Reaction is Associated with Oncological Prognosis and Nutritional Status in Patients with Pathological Stage II/III Gastric Cancer

BACKGROUND

Peritumoral lymphoid aggregates, termed Crohn's-like lymphoid reaction (CLR), are markers of an antitumor immune response, which is an important predictor of patient outcome. In this study, we investigated the prognostic utility of CLR and its relationship with nutritional status in patients with gastric cancer (GC).

METHODS

The study included 170 patients who underwent curative surgery for pathological stage (pStage) II/III GC. The maximum diameters of peritumoral and normal mucosal CLR aggregates were measured, and the median peritumoral diameter (0.57 mm) was used to stratify patients into two groups (large-CLR and small-CLR). The relationships between CLR size and preoperative nutritional status (body mass index, body composition status, Onodera's prognostic nutritional index), tumor-infiltrating CD8+ T-lymphocyte count, and survival were evaluated.

RESULTS

Peritumoral CLR aggregates were significantly larger than aggregates in the normal mucosa. Clinicopathological variables were not significantly different between the two patient groups; however, the large-CLR group had better cancer-specific survival (p = 0.018) and recurrence-free survival (p = 0.03) than the small-CLR group. Multivariate analysis revealed that CLR size was an independent prognostic factor for cancer-specific survival [hazard ratio (HR) 2.13, 95% confidence interval (CI) 1.3-3.56, p = 0.002] and recurrence-free survival (HR 1.96, 95% CI 1.22-3.19, p = 0.005). Nutritional status markers were significantly poorer for the small-CLR group than the large-CLR group. CD8+ T-cell tumor infiltration was positively correlated with CLR size but not with patient survival.

CONCLUSIONS

CLR size correlated with patient nutritional status and prognosis and may be helpful in identifying high-risk populations of pStage II/III GC patients.

Laparoscopic esophagogastrostomy using a knifeless linear stapler after proximal gastrectomy

Proximal gastrectomy should improve the late postoperative function in patients with gastric cancer located in the upper third of the stomach or esophagogastric junction. However, a standard method of esophagogastrostomy has not been established for improving the postoperative function. To prevent reflux and stenosis following proximal gastrectomy, we introduced a novel esophagogastrostomy method using a knifeless linear stapler. The stapler was inserted into holes created in both the esophagus and remnant stomach and fired proximally. A 1.5-cm incision was made from the edge of the entry hole between the staples. The entry hole was then closed with continuous sutures, and fundoplication was performed by wrapping the remnant stomach. We performed this technique in 12 consecutive patients without observing any anastomosis-related complications. The proportion of weight lost 1 year after surgery was 8.8%. Our surgical procedure might be feasible for treating gastric cancer located in the upper third of the stomach or esophagogastric junction.

Rac GTPase-Activating Protein 1 (RACGAP1) as an Oncogenic Enhancer in Esophageal Carcinoma

PURPOSE

Rac GTPase-activating protein 1 (RACGAP1) is associated with cell proliferation, and there is much evidence of its oncogenic role. This study investigated the clinical importance and functional role of RACGAP1 in esophageal carcinoma (EC).

METHODS

A total of 81 EC patients were enrolled in the study. We assessed the immunohistochemical score of EC tissues and adjacent normal esophageal mucosae, and then performed multiple cell function tests by means of in vitro experiments to elucidate the functional role of RACGAP1 using RNA interference technology in EC cell lines.

RESULTS

RACGAP1 was significantly overexpressed in EC tissues compared with the adjacent normal esophageal mucosae (p < 0.0001). Moreover, RACGAP1 overexpression was significantly correlated with poor overall survival (p = 0.032) and disease-free survival (p = 0.012) in EC patients. High RACGAP1 expression was also significantly correlated with the presence of lymphatic invasion (p = 0.012), vessel invasion (p = 0.003), and advanced TNM (tumor-node-metastasis) stage (p = 0.046) in EC patients. In vitro analysis demonstrated that RACGAP1 was involved in the proliferation, tumorigenicity, invasion, migration, and anoikis resistance in EC cells.

CONCLUSIONS

RACGAP1 plays a pivotal role in EC development, suggesting that it could be used as an indicator of prognosis in EC patients.

Circulating miR-203 derived from metastatic tissues promotes myopenia in colorectal cancer patients

BACKGROUND

Sarcopenia frequently occurs in metastatic cancer patients. Emerging evidence has revealed that various secretory products from metastatic tumours can influence host organs and promote sarcopenia in patients with malignancies. Furthermore, the biological functions of microRNAs in cell-to-cell communication by incorporating into neighbouring or distal cells, which have been gradually elucidated in various diseases, including sarcopenia, have been elucidated.

METHODS

We evaluated psoas muscle mass index (PMI) and intramuscular adipose tissue content (IMAC) using pre-operative computed tomography imaging in 183 colorectal cancer (CRC) patients. miR-203 expression levels in CRC tissues and pre-operative serum were evaluated using quantitative polymerase chain reaction. Functional analysis of miR-203 overexpression was investigated in human skeletal muscle cells (SkMCs), and cells were analysed for proliferation and apoptosis. Expressions of several putative miR-203 target genes (CASP3, CASP10, BIRC5, BMI1, BIRC2, and BIRC3) in SKMCs were validated.

RESULTS

A total of 183 patients (108 men and 75 women) were included. The median age of enrolled patients at diagnosis was 68.0 years (range 35-89 years). High IMAC status significantly correlated with female gender (P = 0.004) and older age (P = 0.0003); however, no other clinicopathological factors correlated with IMAC status in CRC patients. In contrast, decreased PMI significantly correlated with female gender (P = 0.006) and all well-established disease development factors, including advanced T stage (P = 0.035), presence of venous invasion (P = 0.034), lymphovascular invasion (P = 0.012), lymph node (P = 0.001), distant metastasis (P = 0.002), and advanced Union for International Cancer Control tumour-node-metastasis stage classification (P = 0.0004). Although both high IMAC status and low PMI status significantly correlated with poor overall survival (IMAC: P = 0.0002; PMI: P < 0.0001; log-rank test) and disease-free survival (IMAC: P = 0.0003; PMI: P = 0.0002; log-rank test), multivariate Cox's regression analysis revealed that low PMI was an independent prognostic factor for both overall survival (hazard ratio: 4.69, 95% confidence interval (CI): 2.19-10, P = 0.0001) and disease-free survival (hazard ratio: 2.33, 95% CI: 1.14-4.77, P = 0.021) in CRC patients. Serum miR-203 expression negatively correlated with pre-operative PMI level (P = 0.0001, ρ = -0.25), and multivariate logistic regression analysis revealed that elevated serum miR-203 was an independent risk factor for myopenia (low PMI) in CRC patients (odds ratio: 5.16, 95% CI: 1.8-14.8, P = 0.002). Overexpression of miR-203 inhibited cell proliferation and induced apoptosis via down-regulation of BIRC5 (survivin) expression in human SkMC line.

CONCLUSIONS

Assessment of serum miR-203 expression could be used for risk assessment of myopenia, and miR-203 might be a novel therapeutic target for inhibition of myopenia in CRC.

Phase I study of preoperative chemoradiotherapy with sequential oxaliplatin and irinotecan with S-1 for locally advanced rectal cancer

The present study designed a novel preoperative chemoradiotherapy (CRT) with sequential oxaliplatin and irinotecan with S-1 for locally advanced rectal cancer (LARC). This phase I study evaluated the maximum tolerated dose and recommended dose (RD) of oxaliplatin following irinotecan with S-1. Patients with clinical stage T3 or 4 or involvement of the regional nodes and no evidence of distant metastases were treated with fixed doses of S-1 (80 mg/m²/day) on days 1-5, 8-12, 15-19, 22-27 and 29-33, and irinotecan (40 mg/m²/day) on days 1 and 8, followed by oxaliplatin on days 22 and 29. The dose of oxaliplatin was initially 40 mg/m² (level 1) with a predefined dose escalation schedule. The radiation dose was 1.8 Gy/fraction to a total dose of 45 Gy. A total of 9 patients were enrolled in the present study and 7 patients completely received CRT with this study protocol. The maximum tolerated dose for oxaliplatin was 50 mg/m² (level 2). Three of four patients experienced dose-limiting toxicity (grade 3 diarrhea) in oxaliplatin phase of level 2 dose. The RD of oxaliplatin was 40 mg/m² (level 1 dose). In addition, 2 patients had pathological CR (28.5%). Novel preoperative CRT with sequential oxaliplatin and irinotecan with S-1 for LARC resulted in acceptable toxicity and promising efficacy. However, the RD of oxaliplatin was lower than in previous CRT studies that combined oxaliplatin with S-1. To administer higher oxaliplatin, we have planned a phase I trial of preoperative CRT with sequential oxaliplatin followed by irinotecan with S-1 for LARC.

Abstract 1066: L1CAM as a pivotal mediator for disease progression and prognostic biomarker in gastric cancer patients

Background/Aims: Although significant progress has been made in the diagnosis and treatment of Gastric cancer (GC) patients, GC is the second leading cause of cancer-related deaths worldwide. Identification of critical factors driving the progression of metastasis and new prognostic biomarkers are urgently required to improve both early detection of recurrence and prognosis of patients with advanced GC. L1 cell adhesion molecule (L1CAM) has been observed to be highly expressed in several types of tumors, which may play a vital role in tumor progression. The present study investigated the clinical significance of L1CAM, in the development and progression of gastric cancer.

Experimental Design: At first, the effects of L1CAM alteration were investigated using proliferation, migration, invasion, and anoikis and xenograft model. Next, we analyzed L1CAM expression in surgical tissue speciemens from 131 gastric cancer patients (Cohort 1) by quantitative real-time reverse transcription-PCR and 309 patients (Cohort 2) by immunohistochemistry.

Results: Knockdown of L1CAM using small interfering RNA in GC cell lines resulted in reduced cell proliferation, invasion, migration, and anoikis in gastric cancer cells. Furthermore, Knockdown of L1CAM inhibited metastasis in a xenograft model. Interestingly, L1CAM expression in cancer tissues was significantly higher in patients with lymph node metastasis and distant metastasis. The expression of L1CAM was significantly associated with poor prognosis. Furthermore, L1CAM emerged as an independent prognostic predictor and a predictor of lymph node metastasis in GC patients.

Conclusions: Our data highlight that L1CAM appear to play an important role in disease development and L1CAM expression may serve as a novel predictor for the identification of patients who are at high risk for tumor recurrence and strict surveillance in curative GC patients.

Citation Format: Yoshinaga Okugawa, Yuji Toiyama, Yasuhiko Mohri, Akira Yamamoto, Tsunehiko Shigemori, Chengzeng Yin, Aya Narumi, Shozo Ide, Takahito Kitajima, Hiromi Yasuda, Hiroyuki Fujikawa, Junichiro Hiro, Shigeyuki Yoshiyama, Masaki Ohi, Koji Tanaka, Toshimitsu Araki, Masato Kusunoki. L1CAM as a pivotal mediator for disease progression and prognostic biomarker in gastric cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1066.

Abstract 4610: Inflammation-associated microsatellite alterations in colorectal cancers (CRCs): Definition, assay, prognostic value, and pathologic significance

Background & Aims. Deficiency in the DNA mismatch repair (MMR) gene product MSH3 results in low levels of microsatellite instability (MSI-L) at dinucleotide loci and elevated microsatellite instability at selected tetranucleotide repeats (EMAST), but not at mononucleotide loci in CRC. We previously demonstrated that the pro-inflammatory cytokine interleukin 6 (IL6) and/or hydrogen peroxide triggers translocation of MSH3 from the nucleus to cytoplasm, resulting in MSI-L/EMAST (L/E). This is consistent with observed correlation between intraepithelial and nests of inflammatory cells within malignant epithelium that are the likely origin of IL6 and oxidative stress with the occurrence of L/E in CRCs, informing that L/E is a consequence of exposure to inflammation. Microbes such as Fusobacterium nucleatum may play a role in CRC initiation and progression, and may trigger inflammation. Clinically, L/E is associated with poor patient prognosis and CRC recurrence and/or metastasis. Threshold values for determining L/E range in the literature from 1 to 3 polymorphic markers frameshifted when compared to normal tissue. Our aim was to assess an optimal threshold value for determining L/E in CRCs.

Materials & Methods. For MSI-H, MSI-L and EMAST status, we developed a multiplex PCR-based assay consisting of 2 mono-, 5 di-, and 7 tetra-nucleotide microsatellite markers. MSI-H was defined when &gt;2/7 mono- and/or di-nucleotide repeats exhibited frameshift mutations (FSM), and MSI-L when &lt;2/7 mono- and/or di-nucleotide markers exhibited FSM. EMAST was defined when 1/7 (relaxed criteria) or &gt;2/7 (stringent criteria) tetranucleotide markers showed FSM. Stage II/III CRCs (132 cases) from Korea were analyzed for the association between L/E and recurrence-free survival (RFS) using relaxed and stringent criteria for EMAST. A second CRC cohort (308 cases) was analyzed for MSI/EMAST and F. nucleatum infection.

Results. When EMAST was defined by relaxed criteria, P value for the association between L/E and RFS of 132 CRC patients was 0.415 while P value was 0.0038 when EMAST defined by stringent criteria was used. Similarly, F. nucleatum infection was associated with L/E by univariate analysis (P=0.027) but not by multivariate analysis (P=0.08) when EMAST was defined by relaxed criteria for 308 CRC cases. In contrast, this became significant in both uni- (P=0.014) and multi-variate analysis (P=0.024) when EMAST was defined by stringent criteria.

Conclusions. A clear distinction for pathological significance is detected between non-MSI-H, L/E CRCs (associated with inflammation) and non-L/E CRCs when EMAST is defined by &lt;2/7 EMAST markers. This threshold may better define EMAST for these observed inflammation-associated microsatellite alterations.

Citation Format: Minoru Koi, Yoshiki Okita, Stephanie Tseng-Rogenski, Koji Munakata, Chan Choi, Hyeong-Rok Kim, Erika Koeppe, Elena Stoffel, Joseph A. Galanko, Nikki McCoy, Temitope Keku, Takahito Kitajima, Takeshi Nagasaka, Yuji Toiyama, John M. Carethers. Inflammation-associated microsatellite alterations in colorectal cancers (CRCs): Definition, assay, prognostic value, and pathologic significance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4610.

Clinical Impact of Muscle Quantity and Quality in Colorectal Cancer Patients: A Propensity Score Matching Analysis

BACKGROUND

Sarcopenia is defined as the loss of skeletal muscle mass, accompanied by decreased muscle strength, and consists of myopenia and myosteatosis. Recent evidence has suggested the predictive value of sarcopenia for the risk of perioperative and oncological outcomes in various malignancies. The aim of this study was to clarify the clinical impact of myopenia and myosteatosis in colorectal cancer (CRC) patients.

METHODS

We analyzed the preoperative psoas muscle mass index and intramuscular adipose tissue content using preoperative computed tomography images from 308 CRC patients using statistical methods.

RESULTS

Despite no significant correlation between myosteatosis and prognosis, preoperative myopenia significantly correlated with clinicopathological factors for disease development, including advanced tumor depth (P = 0.009), presence of lymphatic vessel invasion (P = 0.006), distant metastasis (P = 0.0007), and advanced stage classification (P = 0.013). Presence of preoperative myopenia was an independent prognostic factor for both cancer-specific survival (hazard ratio [HR]: 2.75, 95% confidence interval [CI]: 1.5-5.05, P = 0.001) and disease-free survival (HR: 3.15, 95% CI: 1.8-5.51, P = 0.0001), and was an independent risk factor for postoperative infectious complications in CRC patients (odds ratio: 2.03, 95% CI:1.17-3.55, P = 0.013). Furthermore, these findings were successfully validated using propensity score matching analysis.

CONCLUSIONS

Preoperative myopenia could be useful for perioperative management, and quantification of preoperative skeletal muscle mass could identify patients as a high risk for perioperative and oncological outcomes in CRC patients.

A genome-wide association study identifies two novel susceptibility loci and trans population polygenicity associated with bipolar disorder

Genome-wide association studies (GWASs) have identified several susceptibility loci for bipolar disorder (BD) and shown that the genetic architecture of BD can be explained by polygenicity, with numerous variants contributing to BD. In the present GWAS (Phase I/II), which included 2964 BD and 61 887 control subjects from the Japanese population, we detected a novel susceptibility locus at 11q12.2 (rs28456, P=6.4 × 10-9), a region known to contain regulatory genes for plasma lipid levels (FADS1/2/3). A subsequent meta-analysis of Phase I/II and the Psychiatric GWAS Consortium for BD (PGC-BD) identified another novel BD gene, NFIX (Pbest=5.8 × 10-10), and supported three regions previously implicated in BD susceptibility: MAD1L1 (Pbest=1.9 × 10-9), TRANK1 (Pbest=2.1 × 10-9) and ODZ4 (Pbest=3.3 × 10-9). Polygenicity of BD within Japanese and trans-European-Japanese populations was assessed with risk profile score analysis. We detected higher scores in BD cases both within (Phase I/II) and across populations (Phase I/II and PGC-BD). These were defined by (1) Phase II as discovery and Phase I as target, or vice versa (for 'within Japanese comparisons', Pbest~10-29, R2~2%), and (2) European PGC-BD as discovery and Japanese BD (Phase I/II) as target (for 'trans-European-Japanese comparison,' Pbest~10-13, R2~0.27%). This 'trans population' effect was supported by estimation of the genetic correlation using the effect size based on each population (liability estimates~0.7). These results indicate that (1) two novel and three previously implicated loci are significantly associated with BD and that (2) BD 'risk' effect are shared between Japanese and European populations.

Prognostic impact of sarcopenia and its correlation with circulating miR-21 in colorectal cancer patients

Severe malnutrition accompanied by sarcopenia and cachexia, is strongly associated with the surgical and oncological outcomes in cancer patients. The aim of the present study was to clarify the clinical significance of sarcopenia and its correlation with sarcopenia-associated miRNA in colorectal cancer (CRC). A total of 167 CRC patients were enrolled in the present study. We evaluated psoas muscle mass index (PMI) and intramuscular adipose tissue content (IMAC). The expression of miR-21 in CRC tissues and preoperative serum was evaluated using quantitative PCR. Despite the lack of significant correlation between IMAC and disease-correlated factors, decreased PMI was significantly associated with well-established clinicopathological factors for disease progression. Decreased PMI was an independent prognostic factor for both overall survival and disease-free survival and was an independent risk factor for various types of metastasis. In contrast to the expression of tissue miR-21, the expression of serum miR-21 was significantly increased in CRC patients with low PMI. Furthermore, postoperative PMI was drastically improved compared with preoperative PMI in CRC patients with potentially curative resections. In conclusion, skeletal muscle mass may be a prognostic and predictive biomarker for distant metastasis in CRC patients and quantification of serum miR-21 expression could help clinicians make decisions regarding nutrition intervention strategies in CRC patients.

Feasibility of Assessing Prognostic Nutrition Index in Patients With Rectal Cancer Who Receive Preoperative Chemoradiotherapy

BACKGROUND

Malnutrition can adversely affect treatment responses and oncological outcomes in cancer patients. However, among patients with rectal cancer who undergo chemoradiotherapy (CRT), the significance of peri-treatment nutrition assessment as a predictor of treatment response and outcome remains unclear.

OBJECTIVE

The aim of this study was to determine whether the Prognostic Nutrition Index (PNI) based on peri-treatment serum can be used as a predictor of treatment response and outcome in patients with rectal cancer who undergo CRT.

DESIGN, SETTING, AND PATIENTS

We analyzed 114 patients with rectal cancer who received preoperative CRT followed by total mesorectal excision at our institution.

RESULTS

Post-CRT PNI was significantly lower than pre-CRT PNI in rectal cancer patients. Although post-CRT PNI did not significantly correlate with either overall survival or disease-free survival, low pre-CRT PNI was significantly associated with shorter overall survival and disease-free survival in this population and was also an independent risk factor for ineffectiveness of long-course preoperative CRT. Finally, low pre-CRT PNIs were a stronger indicator of poor prognosis and early recurrence in patients with pathological lymph node metastasis (who generally need to receive postoperative chemotherapy), than in those with no pathological lymph node metastasis.

CONCLUSION

Pretreatment PNI could be useful in evaluating and managing patients with rectal cancer who undergo CRT followed by curative resection.

Abstract 2847: Loss of heterozygosity (LOH) within the hypoxia inducible factor 3A (HIF3A) locus in liver metastasis (LM) from primary colorectal cancer (CRC)

Background and Aims: HIF3α is a hypoxia-regulated transcription factor that represses the effects of HIF1α and HIF2α under hypoxia at transcriptional and posttranslational levels. We previously found that LOH at the HIF3A locus is frequent in LM (59%) and the expression of HIF3A protein is reduced in LM compared to primary CRC. At present, the smallest overlapping LOH (SOL-LOH) region has been mapped to the intron 8 of the HIF3A, spanning from 46,312,911 to 46,315,651 on chromosome 19 in LMs. This genomic region contains multiple FOXA1 binding sites embedded in the two DNase I hypersensitive sites (UCSC Genome Browser, https://genome.UCSC.edu). About 30% of the human population carries a deletion within our SOL-LOH region (1000 Genomes Consortium: esv3644527, Chr19: 46,314,109-46,315,478). In this study, we determined whether esv3644527 deletion affects on the expressions of HIF3A, HIF2A, HIF1A and their target genes under normoxic and hypoxic conditions.

Methods: For LOH mapping, 75 resected LMs derived from primary CRC were analyzed for LOH using 8 polymorphic markers. We obtained three EBV-transformed B cell lines with heterozygous esv3644527 deletion and the one with the homozygous deletion from the Coriell Institute. The expression levels of 23 genes related to HIF pathways were determined by qRT-PCR.

Results and Discussion: The expression levels of HIF3A mRNA were too low to compare among these B cell lines by qRT-PCR. However, the expression levels of HIF2A and its target gene, angiopoietin 2 (ANGPT2), are significantly elevated in B cells with a homozygous deletion compared to B cells with a heterozygous deletion under both normoxic and hypoxic conditions. These observations are compatible with the results obtained from a previous study where pulmonary endothelial cells from HIF3A-knockout mice expressed elevated levels of HIF2A and ANGPT2 (Kobayashi-S et al., Genes Cells, 2015, 20:224-241), suggesting that deletion of the FOXA1 sites present in this region may regulate the HIF3A expression.

Conclusions: Our results show that about 60% of LMs exhibit LOH in the 2.7 Kb region surrounding intron 8 of the HIF3A locus. Deletion within this region may lead to upregulation of HIF2A and ANGPT2 by negatively regulating HIF3A expression. To prove our hypothesis, colon cancer cell lines with deleted FOXA1 sites will be assessed.

Citation Format: Takahito Kitajima, Minoru Koi, Alexander Worix, John M. Carethers. Loss of heterozygosity (LOH) within the hypoxia inducible factor 3A (HIF3A) locus in liver metastasis (LM) from primary colorectal cancer (CRC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2847. doi:10.1158/1538-7445.AM2017-2847

BIOPHYSICAL PROPERTIES OF SUBTHRESHOLD RESONANCE OSCILLATIONS AND SUBTHRESHOLD MEMBRANE OSCILLATIONS IN NEURONS

Subthreshold-level activities in neurons play a crucial role in neuronal oscillations. These small-amplitude oscillations have been suggested to be involved in synaptic plasticity and in determining the frequency of network oscillations. Subthreshold membrane oscillations (STOs) and subthreshold resonance oscillations (SROs) are the main constituents of subthreshold-level activities in neurons. In this study, a general theoretical framework for analyzing the mechanisms underlying STOs and SROs in neurons is presented. Results showed that the resting membrane potential and the hyperpolarization-activated potassium channel (h-channel) affect the subthreshold-level activities in stellate cells. The contribution of h-channel on resonance is attributed to its large time constant, which produces the time lag between I_h and the membrane potential. Conversely, the persistent sodium channels (Nap-channels) only play an amplifying role in these neurons.

Diagnostic Potential of Cell-Free and Exosomal MicroRNAs in the Identification of Patients with High-Risk Colorectal Adenomas

BACKGROUND

Although there is a growing interest in developing circulating microRNA (miRNA) as noninvasive diagnostic biomarkers for the detection of high-risk colorectal adenomas and early-stage CRCs, but the comparative diagnostic significance of serum vs. exosomal miRNAs remains unexplored.

METHODS

Based upon published literature, we performed an initial discovery step by investigating the expression of a miRNA panel in 20 normal colonic mucosa, 27 adenomas, and 19 CRC tissues. We performed subsequent validation by quantifying expression of candidate miRNAs in total serum and in exosomes from 26 adenoma patients and 47 healthy controls, and evaluated their clinical significance and potential diagnostic value in colorectal adenomas.

RESULTS

We observed that the expression of four miRNAs, miR-21, miR-29a, miR-92a, and miR-135b, was significantly higher in colorectal adenomas vs. normal colonic mucosa. During validation, expression of miR-21, miR-29a and miR-92a in serum was significantly higher in adenomas vs. healthy controls, significantly correlated with adenoma size and total adenoma number within the colorectum, and significantly discriminated patients with advanced adenomas. In contrast, although exosomal miR-21 and miR-29a levels in adenoma patients were significantly higher than those of healthy volunteers, only exosomal miR-21 significantly correlated with adenoma size and total adenoma number, and could discriminate patients with high-risk adenomas.

CONCLUSION

Compared to exosomal miRNAs, serum levels of miR-21, miR-29a and miR-92a are superior diagnostic biomarkers in patients with high-risk adenomatous polyps.