TCR sequencing analysis of cancer tissues and tumor draining lymph nodes in colorectal cancer patients

Tumor draining lymph nodes (TDLNs) are located in the routes of lymphatic drainage from a primary tumor and have the highest risk of metastasis in various types of solid tumors. TDLNs are also considered as a tissue to activate the antitumor immunity, where antigen-specific effector T cells are generated. However, T cell receptor (TCR) repertoires in TDLNs have not been well characterized. We collected 23 colorectal cancer tumors with 203 lymph nodes with/without metastatic cancer cells (67 were metastasis-positive and the remaining 136 were metastasis-negative) and performed TCR sequencing. Metastasis-positive TDLNs showed a significantly lower TCR diversity and shared TCR clonotypes more frequently with primary tumor tissues compared to metastasis-negative TDLNs. Principal component analysis indicated that TDLNs with metastasis showed similar TCR repertoires. These findings suggest that cancer-reactive T cell clones could be enriched in the metastasis-positive TDLNs.

Clinical significance of soluble programmed cell death-1 and soluble programmed cell death-ligand 1 in patients with locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy

Background

Inhibition of the programmed cell death-1/programmed cell death-ligand 1 (PD-1/PD-L1) axis in combination with radiotherapy may be a promising approach to treat cancer. In the present study, we aimed to evaluate serum soluble PD-1/PD-L1 levels in patients with advanced rectal cancer treated with neoadjuvant chemoradiotherapy (CRT).

Methods

Serum soluble PD-L1 and PD-1 levels were measured using an enzyme-linked immunosorbent assay before and after CRT in 117 patients with low rectal cancer. Changes in the levels of sPD-L1/PD-1 after CRT, and the correlation between sPD-L1/PD-1 level and clinicopathological characteristics or disease-free survival (DFS) were evaluated.

Results

sPD-L1 levels significantly increased after CRT (p < 0.0001), whereas sPD-1 levels did not change significantly (p = 0.1050). High sPD-L1 before CRT was significantly associated with younger age (p = 0.044), and after CRT, with lymphovascular invasion (p = 0.021). High sPD-1 before and after CRT was significantly associated with a longer distance of the tumor from the anal verge (both p < 0.001). There was no correlation between sPD-L1 level and local PD-L1 expression on stromal immune cells. High sPD-L1 level after CRT tended to be associated with worse DFS (p = 0.0752). The multivariate analysis could not demonstrate an independent association for sPD-L1 levels after CRT with DFS.

Conclusions

Significant increase of sPD-L1 levels after CRT suggests that anti-PD-L1 therapy might be a potential treatment strategy in combination with CRT in advanced rectal cancer.

Difficulty of predicting lymph node metastasis on CT in patients with rectal neuroendocrine tumors

Background

Surgical indications for rectal neuroendocrine tumors with potential lymph node metastasis remain controversial. Although accurate preoperative diagnosis of nodal status may be helpful for treatment strategy, scant data about clinical values of lymph node size have been reported. The aim of this retrospective study was to investigate the relationship between lymph node size and lymph node metastasis.

Methods

Participants comprised 102 patients who underwent rectal resection with total mesenteric excision or tumor-specific mesenteric excision and in some cases additional lateral pelvic lymph node dissection for rectal neuroendocrine tumor between June 2005 and September 2016. All lymph nodes from specimens were checked and measured.

Results

Pathological lymph node metastasis was confirmed in 37 patients (36%), including 6 patients (5.8%) with lateral pelvic lymph node metastasis. A total of 1169 lymph nodes in the mesorectum were retrieved from all specimens, with 78 lymph nodes (6.7%) showing metastasis. Mean length (long-axis diameter) of metastatic lymph nodes in the mesorectum was 4.31 mm, significantly larger than that of non-metastatic lymph nodes (2.39 mm, P<0.01). The optimal cut-off of major axis length for predicting mesorectal lymph node metastasis was 3 mm. We could predict lymph node metastasis in only 7 patients (21%) from preoperative multidetector-row computed tomography.

Conclusions

Metastatic lymph nodes were small, so predicting lymph node metastasis from preoperative computed tomography is difficult. Alternative modalities with a scan width less than 3 mm may be needed to predict lymph node metastasis of rectal NET with low cost and labour requirements.

Role of enterocyte-specific gene polymorphisms in adjuvant treatment for stage III colorectal cancer

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Background: Enterocyte subtype of the Colorectal Cancer (CRC) Assigner classifier is known as favorable to oxaliplatin-based adjuvant treatment for stage III CRC. We previously reported potential predictive value of single nucleotide polymorphisms (SNPs) in enterocyte-related genes in metastatic CRC (Suenaga, ASCO2018). In this study, we examined clinical significance of MS4A12 and CDX2 SNPs in adjuvant treatment (AT) for Stage III CRC. Methods: 350 patients with Stage III CRC were included in this study: 274 received AT (discovery cohort: median age = 62, median follow-up = 59.9 months) and 76 received surgery alone (control: median age = 75, median follow-up = 58.0 months). 68 and 206 patients received FOLFOX and oral fluoriopyrimidine, respectively. SNPs were analyzed by PCR-based direct sequencing. Disease-free survival and overall survival (OS) were analyzed using Kaplan-Meier curves, log-rank test, and Cox proportional hazards regression. Results: In discovery cohort, the G/G variant in MS4A12 rs4939378 was associated with lower 5-y survival rate than any A allele in uni- and multi-variate analyses (70% vs 90%, univariate: HR 2.29, 95% CI: 1.03-5.06, P = 0.035; multivariable: HR 2.58, 95% CI: 1.15-5.76, P = 0.021). Patients with the G/G variant in CDX2 rs3812863 had better OS than those with any A, though not significant in multivariable analysis (5 y-survival rate: 95% vs 82%, univariate: HR 0.34, 95% CI: 0.12-0.97, P = 0.034; multivariable: HR 0.39, 95% CI: 0.13-1.11, P = 0.078). There was no significance in the control, and significant interaction was observed between MS4A12 genotypes and groups (interaction P = 0.007). In addition, there was no interaction between MS4A12 rs4939378 and FOLFOX vs oral fluoropyrimidine. Conclusions: Our findings suggest that MS4A12 and CDX2 gene polymorphisms may predict outcome in patients with Stage III CRC. However, clinical significance of the SNPs for oxaliplatin seems to differ depending on tumor stage. Further research and validation study are warranted to explore the association of the SNPs with carcinogenesis or cancer progression.

Transverse single spin asymmetry for very forward π0 production in polarized proton-proton collisions at √s = 510 GeV

Transverse single spin asymmetry, AN, of very forward π0 production from polarized p + p collisions provides new information toward an understanding of its production mechanism. AN of forward π0 in the pseudorapidity region of 3 < η < 4 has been described by the partonic structure of the proton in the perturbative QCD framework. However, recent data indicates a potential contribution from not only partonic but also diffractive interactions. In order to provide a new insight on the origin of the AN, we measured the very forward π0 production in the pseudorapidity region of 6 < η from √s = 510 GeV polarized p + p collisions at RHIC in 2017. We report our measurement of the very forward π0 over the transverse momentum range of 0 < pT < 1 GeV/c and the preliminary result.

Laparoscopic right hemicolectomy for a colon cancer patient with an ileal conduit

Here, we describe our experience of laparoscopic surgery in a colon cancer patient with an ileal conduit. To our knowledge, this is the second case presented in the English-language literature. A 71-year-old woman with a history of both open anterior exenteration with ileal conduit reconstruction for bladder cancer and open cholecystectomy for cholecystitis was diagnosed with ascending colon cancer (cT3N1M0). Laparoscopic right hemicolectomy with conduit preservation was planned. After adhesiolysis, complete mesocolic excision and central vascular ligation were achieved laparoscopically without injury to the conduit or other structures. Laparoscopic surgery for patients with an ileal conduit can be technically demanding. A preoperative plan based on preoperative imaging and the patient's previous operative record is crucial, especially when considering the optimal balance between oncological radicality and functional outcomes.

Recent results from the LHCf and RHICf experiments

The Large Hadron Collider forward and the Relativistic Heavy Ion Collider forward experiments measured forward particles produced in high-energy hadron collisions at the LHC and RHIC. Using compact calorimeters neutral particles produced in pseudorapidities η >8.4 and η >6.0 are observed by the respective experiments. Because the collision energies ranging from 0.51 TeV to 13 TeV correspond to the cosmic-ray equivalent energies of 1014 to 1017 eV, the measurements are important to understand the hadronic interaction relevant to extensive air shower measurements. This paper reviews recent results of LHCf and initial performance of RHICf that took data in the 2017 RHIC operation.

Laparoscopic and endoscopic cooperative surgery (LECS) to overcome the limitations of endoscopic resection for colorectal tumors

Background and study aims  We developed a laparoscopy endoscopy cooperative surgery (LECS) to overcome the limitations of endoscopic resection for colorectal tumors. The aim of this study was to evaluate the feasibility of LECS, which combines endoscopic submucosal dissection (ESD) and laparoscopic partial colectomy. Patients and methods  We performed LECS for 17 colorectal tumors in 17 patients (male:female 10:7; mean age, 66.5 years). The clinicopathological outcomes of these 17 cases and the feasibility of LECS were evaluated retrospectively. Indications for LECS were as follows: 1) intramucosal cancer and adenoma accompanied by wide and severe fibrosis; 2) intramucosal cancer and adenoma involving the diverticulum or appendix; and 3) submucosal tumors. Results  We successfully performed LECS procedures in 17 cases (intramucosal cancer [n = 6], adenoma [n = 9], schwannoma [n = 1], and gastro-intestinal stromal tumour [GIST] [n = 1]. Mean tumor diameter was 22.4 mm (range, 8 - 41 mm). LECS was successfully performed in all 17 cases without conversion to open surgery; the R0 rate was 100 %. LECS was applied to the following situations: involving the appendix (n = 6), tumor accompanied by severe fibrosis (n = 5), involving the diverticulum (n = 3), submucosal tumor (n = 2), and poor endoscopic operability (n = 1). We experienced no adverse events (e. g., leakage or anastomotic stricture) and the median hospital stay was 6.4 dayus (range, 4 to 12). All 17 patients who were followed for ≥ 3 months (median, 30.8 months; range, 3 - 72 months) showed no residual/local recurrence. Conclusion  LECS was a safe, feasible, minimally invasive procedure that achieved full-thickness resection of colorectal tumors and showed excellent clinical outcomes.

Laparoscopic repair of bowel herniation into the space between the obturator nerve and the umbilical artery after pelvic lymphadenectomy for cervical cancer

Bowel herniation through the space between the exposed structures after pelvic lymphadenectomy is a very rare cause of postoperative bowel obstruction. Here, a case of laparoscopic release of bowel migration into the space after pelvic lymphadenectomy is described. This is the seventh such reported case in the world. A 38-year-old woman who had a history of undergoing laparoscopic radical hysterectomy and bilateral pelvic lymphadenectomy for cervical cancer was diagnosed with strangulated bowel obstruction. Emergency laparoscopic surgery was performed, and bowel migration into the space between the right umbilical artery and the obturator nerve was detected. The loop of strangulated bowel was released laparoscopically, and bowel blood flow was improved. To prevent recurrence of bowel migration, the umbilical artery was resected. It is very important to consider the possibility of bowel herniation into the space between exposed structures in patients with bowel obstruction after minimally invasive pelvic lymphadenectomy.

Serum leucine-rich alpha-2-glycoprotein-1 with fucosylated triantennary N-glycan: a novel colorectal cancer marker

BACKGROUND

Carcinoembryonic antigen (CEA) and carbohydrate antigen (CA)19-9 are used in clinical practice as tumor markers to diagnose or monitor colorectal cancer (CRC) patients, However, their specificities and sensitivities are not ideal, and novel alternatives are needed. In this study, mass spectrometry was used to search for screening markers, focusing on glycan alterations of glycoproteins in the sera of CRC patients.

METHODS

Glycopeptides were prepared from serum glycoproteins separated from blood samples of 80 CRC patients and 50 healthy volunteers, and their levels were measured by liquid chromatography time-of flight mass spectrometry (LC-TOF-MS).

RESULTS

Leucine-rich alpha-2-glycoprotein-1 with fucosylated triantennary N-glycan (LRG-FTG) was identified as CRC marker after evaluating 30,000 candidate glycopeptide peaks. The average LRG-FTG level in CRC patients (1.25 ± 0.973 U/mL) was much higher than that in healthy volunteers (0.496 ± 0.433 U/mL, P < 10^- 10), and its sensitivity and specificity exceeded those of CA19-9. The combination of CEA and LRG-FTG showed a complementary effect and had better sensitivity (84%), specificity (90%), and AUC (0.91 by ROC analysis) than each marker alone or any other previously reported marker. LRG-FTG alone or combined with CEA also corresponded well with patient response to treatment.

CONCLUSIONS

We identified LRG-FTG as a new CRC marker, with a sensitivity and specificity exceeding CA19-9. The combination of LRG-FTG and CEA showed much higher sensitivity and specificity than each marker alone. Further validation beyond this initial exploratory cohort is warranted.

Skeletal muscle loss is an independent negative prognostic factor in patients with advanced lower rectal cancer treated with neoadjuvant chemoradiotherapy

Background

The impact of body composition on the short- or long-term outcomes of patients with surgically treated advanced rectal cancer after neoadjuvant chemoradiotherapy remains unclear. This study examined the correlation between low skeletal muscle mass and morbidity and survival in patients with advanced lower rectal cancer.

Methods

We enrolled 144 clinical stage II/III patients with advanced lower rectal cancer who underwent neoadjuvant chemoradiotherapy followed by curative resection between 2004 and 2011. The cross-sectional skeletal muscle area at the third lumbar vertebra (L3) level was evaluated by computed tomography before chemoradiotherapy, and this was normalized by the square of the height to obtain the skeletal muscle index. Low skeletal muscle mass was defined as the sex-specific lowest quartile of the L3 skeletal muscle index. The association between low skeletal muscle mass and morbidity, relapse-free survival, or overall survival was assessed.

Results

Low skeletal muscle mass was identified in 37 (25.7%) patients. Age and body mass index were associated with low skeletal muscle mass. By multivariate analysis, we found that low skeletal muscle mass was independently associated with poor overall survival (hazard ratio = 2.93; 95%CI: 1.11–7.71; p = 0.031) and relapse-free survival (hazard ratio = 2.15; 95%CI: 1.06–4.21; p = 0.035), but was not associated with the rate of postoperative complications.

Conclusions

Low skeletal muscle mass is an independent negative prognostic factor for relapse-free and overall survival in patients with advanced lower rectal cancer treated with neoadjuvant chemoradiotherapy.

A Feasibility Study of Capecitabine and Oxaliplatin for Patients with Stage II/III Colon Cancer -ACTOR Study

BACKGROUND/AIM

Past studies have suggested that adjuvant capecitabine and oxaliplatin (CAPOX) provides decreased tumor relapse and longer survival in patients with curatively resected colon cancer. We report the first evidence of the feasibility of adjuvant CAPOX in Japanese patients with early colon cancer.

PATIENTS AND METHODS

Eligible patients had histologically-confirmed stage II/III colon cancer and received curative resection. The primary endpoint was completion rate of treatment after 8 cycles of adjuvant CAPOX.

RESULTS

Thirty-six patients were enrolled in this study. The completion rate of CAPOX and oxaliplatin were 77.8% and 61.1%, respectively. The incidence of grade ≥3 adverse events was neutropenia (n=6), thrombocytopenia (n=3), nausea (n=5), hand-foot syndrome (n=1) and peripheral sensory neuropathy (n=1). Three-year disease-free survival for stage II patients and stage III patients were 100% and 79.3%, respectively.

CONCLUSION

Adjuvant CAPOX can be safely administered to Japanese patients with stage II/III colon cancer.