Evaluation of the RAS signaling network in response to MEK inhibition using organoids derived from a familial adenomatous polyposis patient

RAS signaling is a promising target for colorectal cancer (CRC) therapy, and a variety of selective inhibitors have been developed. However, their use has often failed to demonstrate a significant benefit in CRC patients. Here, we used patient-derived organoids (PDOs) derived from a familial adenomatous polyposis (FAP) patient to analyze the response to chemotherapeutic agents targeting EGFR, BRAF and MEK. We found that PDOs carrying KRAS mutations were resistant to MEK inhibition, while those harboring the BRAF class 3 mutation were hypersensitive. We used a systematic approach to examine the phosphorylation of RAS effectors using reverse-phase protein array (RPPA) and found increased phosphorylation of MEK induced by binimetinib. A high basal level of ERK phosphorylation and its rebound activation after MEK inhibition were detected in KRAS-mutant PDOs. Notably, the phosphorylation of EGFR and AKT was more closely correlated with that of MEK than that of ERK. Transcriptome analysis identified MYC-mediated transcription and IFN signaling as significantly correlated gene sets in MEK inhibition. Our experiments demonstrated that RPPA analysis of PDOs, in combination with the genome and transcriptome, is a useful preclinical research platform to understand RAS signaling and provides clues for the development of chemotherapeutic strategies.

T-cell complexity and density are associated with sensitivity to neoadjuvant chemoradiotherapy in patients with rectal cancer

Emerging evidence suggests that an increased density of pre-treatment CD8⁺ tumor-infiltrating lymphocytes (TILs) is associated with good response to chemoradiotherapy (CRT) in patients with locally advanced rectal cancer. However, the significance of T-cell complexity in the clinical setting remains unknown. High-throughput T-cell receptor (TCR) β sequencing was applied to quantify the TCR repertoire of pre-treatment biopsies from 67 patients with advanced rectal cancer receiving preoperative CRT. Diversity index was used to represent the complexity of the TCR repertoire in a tumor. Pre-treatment CD8⁺ TIL densities were assessed by immunohistochemistry. Changes in TCR repertoire before and after CRT were also analysed in 23 patients. Diversity indices were significantly higher for good responders than for non-responders (P = 0.031). The multivariate analysis revealed that both CD8⁺ TIL density and TCR diversity index were independently associated with good response to CRT (P < 0.001 and P = 0.049, respectively). Patients who were high for both CD8⁺ TIL density and TCR diversity (double-high) had markedly better responses to CRT than double-low patients (84.2% vs 16.7%, P < 0.0001). Larger changes in TCR repertoires before and after CRT were correlated with better recurrence-free survival (P = 0.027). The complexity and dynamic change in the TCR repertoire might serve as a useful indicator of response to CRT in combination with CD8⁺ TIL density in patients with rectal cancer.

Radiomics Approach Outperforms Diameter Criteria for Predicting Pathological Lateral Lymph Node Metastasis After Neoadjuvant (Chemo)Radiotherapy in Advanced Low Rectal Cancer

BACKGROUND

Advanced low rectal cancer has a non-negligible risk of lateral pelvic lymph node (LPLN) metastasis (LPLNM) and lateral local recurrence (LR) after neoadjuvant (chemo)radiotherapy and total mesorectal excision. LPLN dissection (LPLND) reduces LR but increases postoperative complications and sexual/urinary dysfunction.

OBJECTIVE

The aim of this study was to develop a new radiomics-based prediction model for LPLNM in patients with rectal cancer.

METHODS

A total of 247 patients with rectal cancer and enlarged LPLNs treated by (chemo)radiotherapy and LPLND were enrolled in this retrospective, multicenter study. LPLN radiomic features were extracted from pretreatment portal venous-phase computed tomography images. A radiomics score of LPLN was constructed based on the least absolute shrinkage and selection operator regression in a primary cohort of 175 patients. Model performance was assessed in terms of discrimination, calibration, and decision curve analysis, and was externally validated in 72 patients.

RESULTS

The radiomics score showed significantly better discrimination compared with pretreatment short-axis diameter measurements in both the primary (area under the curve [AUC] 0.91 vs. 0.83, p = 0.0015) and validation (AUC 0.90 vs. 0.80, p = 0.0298) cohorts. Decision curve analysis also indicated the superiority of the radiomics score. In a subanalysis of patients with a short-axis diameter ≥ 7 mm, the radiomics nomogram, incorporating the radiomics score and LPLN shrinkage to ≤ 4 mm, had better discrimination compared with a model incorporating only LPLN shrinkage in both cohorts.

CONCLUSIONS

Radiomics-based prediction modeling provides individualized risk estimation of LPLNM in rectal cancer patients treated with (chemo)radiotherapy, and outperforms measurements of pretreatment LPLN diameter.

Clinical significance of clonal hematopoiesis in the interpretation of blood liquid biopsy

As the use of next-generation sequencing (NGS) for plasma cell-free DNA (cfDNA) continues to expand in clinical settings, accurate identification of circulating tumor DNA mutations is important to validate its use in the clinical management for cancer patients. Here, we aimed to characterize mutations including clonal hematopoiesis (CH)-related mutations in plasma cfDNA and tumor tissues using the same ultradeep NGS assay and evaluate the clinical significance of CH-related mutations on the interpretation of liquid biopsy results. Ultradeep targeted NGS using Oncomine Pan-Cancer Panel was performed on matched surgically resected tumor tissues, peripheral blood cells (PBCs), and 120 plasma cfDNA samples from 38 colorectal cancer patients. The clinical significance of the CH-related mutations in plasma cfDNA was evaluated by longitudinal monitoring of the postoperative plasma samples. Among the 38 patients, 74 nonsynonymous mutations were identified from tumor tissues and 64 mutations from the preoperative plasma samples. Eleven (17%) of the 64 mutations identified in plasma cfDNA were also detected in PBC DNA and were identified to be CH-related mutations. Overall, 11 of 38 (29%) patients in this cohort harbored at least one CH-related mutation in plasma cfDNA. These CH-related mutations were continuously detected in subsequent postoperative plasma samples from three patients which could be misinterpreted as the presence of residual disease or as lack of treatment response. Our results indicated that it is essential to integrate the mutational information of PBCs to differentiate tumor-derived from CH-related mutations in liquid biopsy analysis. This would prevent the misinterpretation of results to avoid misinformed clinical management for cancer patients.

Congestive ischemic colitis occurring after resection of left colon cancer: 4 case series

BACKGROUND

Ischemic colitis can occur after colectomy and is sometimes difficult to treat. We report 4 cases of refractory, delayed onset, regional congestive colitis occurring on the anal side of the anastomosis after laparoscopic left hemicolectomy.

CASE PRESENTATION

A total of 191 patients underwent surgery for left colon cancer (transverse, descending, and sigmoid colon cancer) at our hospital from January 2012 to December 2017. During the procedures, the left colic artery (LCA) or sigmoid colic artery (SA) was dissected, the superior rectal artery (SRA) was preserved, and the inferior mesenteric vein (IMV) was dissected at the inferior margin of the pancreas. Congestive ischemic colitis due to venous return dysfunction occurred in 4 cases (2.1%), 5 to 34 months postoperatively. The patients had diarrhea and blood in the stool. On computed tomography (CT), the patients exhibited continuous intestinal edema and high-density adipose tissue from the anastomosis site to the rectum. Contrast enhancement showed dilation of the vasa recti and arteries from the inferior mesenteric artery (IMA) to the SRA. Three patients improved with long-term intestinal rest; in 1 case, the stenosis did not improve and required colorectal resection.

CONCLUSION

Diagnoses were easy in these cases, but treatment was prolonged and surgery was necessary in 1 case. While this condition is rare, caution is warranted as it is difficult to treat.

Primary Tumor Histology Affects Oncological Outcomes Independently of the Anatomical Extent of Disease in Colorectal Liver Metastasis

Introduction

Growing evidence indicates the prognostic importance of the crosstalk between cancer cells and stroma through the induction of epithelial-mesenchymal transition (EMT). This study aimed to clarify the prognostic value of evaluating primary tumor histology with the anatomical extent of disease in patients with colorectal liver metastasis (CRLM).

Methods

Prognostic analyses were performed in 411 CRLM patients who underwent hepatectomy at two institutions. Tumors were graded into one of three histological categories based on integrated assessment of EMT-associated histology (Histology^EMT) in primary tumors, i.e., poorly differentiated clusters (PDCs) and desmoplastic reaction (DR).

Results

A prognostic grouping system for the anatomical extent of disease (N stage, liver metastasis number and size, and extrahepatic disease; Grade^anatomical) stratified patients into three groups with different five-year relapse-free survival (RFS) rates after hepatectomy: A, 31% (191 patients); B, 15% (124 patients); and C, 6% (96 patients; P < 0.0001). Histology^EMT (A, G1 PDC and mature-type DR; C, G3 PDC and immature-type DR; and B, others) identified 49, 120, and 242 patients with 46%, 5%, and 22% five-year RFS, respectively (P < 0.0001). Among prognostic factors, the Akaike information criterion was most favorable in Grade^anatomical, followed by Histology^EMT. Multivariate analysis demonstrated that these two factors independently impacted RFS; two-year RFS after hepatectomy in different patient groups had a wide range (10%-76%).

Conclusions

Histological assessment of dedifferentiation and the stromal environment of primary tumors contributed to effective risk stratification of early relapse after hepatectomy, which could be useful to determine clinical management for CRLM patients.

Transverse Single-Spin Asymmetry for Very Forward Neutral Pion Production in Polarized p+p Collisions at sqrt[s]=510 GeV

Transverse single-spin asymmetries of very forward neutral pions generated in polarized p+p collisions allow us to understand the production mechanism in terms of perturbative and nonperturbative strong interactions. During 2017, the RHICf Collaboration installed an electromagnetic calorimeter in the zero-degree region of the STAR detector at the Relativistic Heavy Ion Collider (RHIC) and measured neutral pions produced at pseudorapidity larger than 6 in polarized p+p collisions at sqrt[s]=510  GeV. The large nonzero asymmetries increasing both in longitudinal momentum fraction x_{F} and transverse momentum p_{T} have been observed at low transverse momentum p_{T}<1  GeV/c for the first time, at this collision energy. The asymmetries show an approximate x_{F} scaling in the p_{T} region where nonperturbative processes are expected to dominate. A non-negligible contribution from soft processes may be necessary to explain the nonzero neutral pion asymmetries.

Serial circulating tumour DNA analysis for locally advanced rectal cancer treated with preoperative therapy: prediction of pathological response and postoperative recurrence

BACKGROUND

The "watch-and-wait" approach is a common treatment option amongst patients with locally advanced rectal cancer (LARC). However, the diagnostic sensitivity of clinical modalities, such as colonoscopy and magnetic resonance imaging to determine pathological response, is not high. We analysed the clinical utility of circulating tumour DNA (ctDNA) of patients with LARC to predict response to preoperative therapy and postoperative recurrence.

METHODS

A serial ctDNA analysis of 222 plasma samples from 85 patients with LARC was performed using amplicon-based deep sequencing on a cell-free DNA panel covering 14 genes with over 240 hotspots.

RESULTS

ctDNA was detected in 57.6% and 22.3% of samples at baseline and after preoperative treatment, respectively, which was significantly different (P = 0.0003). Change in ctDNA was an independent predictor of complete response to preoperative therapy (P = 0.0276). In addition, postoperative ctDNA and carcinoembryonic antigen (CEA) were independent prognostic markers for risk of recurrence after surgery (ctDNA, P = 0.0127 and CEA, P = 0.0105), with a combined analysis having cumulative effects on recurrence-free survival (P = 1.0 × 10^-16).

CONCLUSIONS

Serial ctDNA analysis may offer clinically useful predictive and prognostic markers for response to preoperative therapy and postoperative recurrence in patients with LARC.

Prognostic nutritional index and postoperative outcomes in patients with colon cancer after laparoscopic surgery

PURPOSE

The prognostic nutritional index (PNI) is calculated using the serum albumin and peripheral lymphocyte counts. We sought to assess the correlation between the preoperative PNI and postoperative outcomes in patients with colon cancer treated with laparoscopic surgery.

METHODS

We included 896 colon cancer patients who underwent curative laparoscopic colectomy between January 2013 and March 2016. To identify any predictors of the postoperative outcomes, we compared the clinical characteristics and immunonutritional parameters, including the PNI, between patients classified as the Clavien-Dindo grade 2 or higher (n = 99) with those classified as grade 0 or 1 (n = 797).

RESULTS

A longer surgical time and a preoperative low PNI (< 49.8) (odds ratio; 1.913, p = 0.002) were independent predictors of postoperative complications according to a multivariate analysis. A preoperative low PNI was significantly associated with an older age, a lower performance status, a lower BMI, higher CEA levels, an advanced T status, lymph node metastasis, a longer operative time, a higher blood loss, a larger tumor size, treatment with a combined resection, a longer time to bowel recovery, a longer postoperative hospital stay, and a poor overall survival.

CONCLUSIONS

A preoperative low PNI was found to be significantly associated with the incidence of postoperative complications, an advanced tumor status, and a poor prognosis. Further research is needed to understand how to best clinically utilize this promising parameter.

Educational system for acquiring appropriate laparoscopic colorectal surgical skills: analysis in a Japanese high-volume cancer center

BACKGROUND

Acquiring appropriate laparoscopic technique is necessary to safely perform laparoscopic surgery. The Endoscopic Surgical Skill Qualification System of the Japanese Society of Endoscopic Surgery, which was established to improve the quality of laparoscopic surgery in Japan, provides training to become an expert laparoscopic surgeon. In this study, we describe our educational system, in a Japanese highest volume cancer center, and evaluate the system according to the pass rate for the Endoscopic Surgical Skill Qualification System examination.

METHODS

We assessed 14 residents who trained for more than 2 years from 2012 to 2018 in our department. All teaching surgeons, qualified by the Endoscopic Surgical Skill Qualification System, participated in all surgeries as supervisors. For the first 3 months, trainees learned as the scopist, then as the first assistant for 3 months, and then by performing laparoscopic surgery as an operator during ileocecal resection or sigmoidectomy. Trainees apply for this training in their second year of residency or later. All laparoscopic procedures in our department are standardized in detail.

RESULTS

The cumulative pass rate was 75% (12/16), and 87% (12/14) of the trainees eventually passed, while the general pass rate was approximately 30%. On average, those who passed in their second or third year had experienced 94 procedures as the surgeon, 177 as the first assistant, and 199 as the scopist. The number of laparoscopic procedures and the learning curves did not differ between successful and failed applicants.

CONCLUSIONS

Through our educational system, residents successfully acquired laparoscopic skills with a much higher pass rate in the Endoscopic Surgical Skill Qualification System examination than the general standard. Laparoscopic practice under supervision by experienced surgeons with standardized procedures and accurate understanding of the relevant anatomy is very helpful to achieving appropriate laparoscopic technique.

Abstract A46: Next-generation sequencing of circulating tumor DNA for detecting minimal residual disease and predicting recurrence in colorectal cancer patients

Background: Although the prognosis of colorectal cancer (CRC) has improved in the past decade, a subset of CRC patients may still suffer from relapse due to the progression from minimal residual disease (MRD) after surgical resection. A sensitive and noninvasive method to efficiently detect MRD is essential to further improve clinical prognosis. In this study, we have evaluated the feasibility of circulating tumor DNA (ctDNA) analysis in detecting MRD in CRC patients.

Methods: Plasma samples were prospectively collected from 38 CRC patients, ranging from stage I to IV, who underwent surgical resection. A preoperative blood sample was taken just before surgery and postoperative samples were collected on multiple time-points to monitor the changes of mutation profiles. The extracted nucleic acid from matched surgically resected tumor tissues, peripheral blood cells (PBCs), and plasma were subjected to ultradeep targeted next-generation sequencing (NGS) using Oncomine Pan-Cancer Panel.

Results: Cell-free DNA/RNA (cfDNA/RNA) was extracted from 208 preoperative and postoperative plasma samples with a median input of 20 ng for targeted-NGS (ranged from 8-20 ng). The median of sequencing depth, molecular coverage, and barcode tagging efficiency of the sequencing were 54,000x, 4,642x and 84%, respectively. 74 nonsynonymous mutations were identified from tumor tissues and 64 mutations from the preoperative plasma samples. 41 (64.1%) of the 64 mutations detected in plasma samples were concordantly identified from the tumor tissue DNA. Paired PBCs sequencing identified 11 of the mutations detected from plasma and 4 mutations detected from tumor tissues to be clonal hematopoiesis-related mutations. After the exclusion of clonal hematopoiesis-related mutations, 34 (89.5%) of the 38 patients harbor at least one preoperative mutation either from tumor tissue or plasma to be monitored postoperatively. Fourteen patients were detected with ctDNA mutations from postoperative plasma samples and to date, two of them have developed clinical recurrence. One patient was detected to carry TP53-G245D and KRAS-A146T from both the preoperative plasma and resected-tumor tissue. Both mutations were not detected from plasma during adjuvant chemotherapy. At 4.5 months after the completion of chemotherapy, both mutations were positively detected from plasma with no signs of radiologic or clinical evidence of recurrence. Clinical recurrence was confirmed by PET scan 3 months after the detection of molecular recurrence from ctDNA. Similarly, positive ctDNA mutations also preceded radiologic and clinical evidence of recurrence by 3.5 months in another patient who has developed recurrence.

Conclusions: Our current results indicate that ctDNA analysis allows the detection of MRD in CRC patients. The integration of ctDNA analysis with current standard monitoring guidelines holds great promise in early detection of recurrence to allow clinical intervention to be applied promptly.

Citation Format: Hiu Ting Chan, Satoshi Nagayama, Yoon Ming Chin, Masumi Otaki, Rie Hayashi, Kazuma Kiyotani, Yosuke Fukunaga, Masashi Ueno, Yusuke Nakamura, Siew-Kee Low. Next-generation sequencing of circulating tumor DNA for detecting minimal residual disease and predicting recurrence in colorectal cancer patients [abstract]. In: Proceedings of the AACR Special Conference on Advances in Liquid Biopsies; Jan 13-16, 2020; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(11_Suppl):Abstract nr A46.

The application of dynamic monitoring of circulating tumor DNA for detecting minimal residual disease and predicting recurrence in colorectal cancer patients

e15531

Background: Although the prognosis of colorectal cancer (CRC) has improved in the past decade, a subset of CRC patients may still suffer from relapse due to the progression from minimal residual disease (MRD) after surgical resection. A sensitive and non-invasive method to detect MRD and early diagnosis of recurrence disease is warranted to start therapeutic interventions at an earlier timing and improving the overall survival rate. In this study, we have evaluated the feasibility of circulating tumor DNA (ctDNA) analysis to detect MRD and early detection of recurrence in CRC patients. Methods: Plasma samples were collected prospectively from 38 CRC patients (stage I to IV), who underwent surgical resection. Preoperative blood samples were obtained just before surgery and post-operative samples were collected at multiple time-points to monitor the changes of tumor mutation profiles. Tumor-derived mutations were detected in preoperative blood samples as well as surgically resected-tumor tissues using ultradeep targeted next generation sequencing. Patient-paired peripheral blood cells (PBCs) were sequenced concurrently to exclude clonal hematopoiesis-related mutations. Results: Among the 38 patients, 74 non-synonymous mutations were identified in tumor tissues and 64 mutations in the preoperative plasma samples. Paired PBCs sequencing identified 11 mutations in plasma samples to be clonal hematopoiesis-related mutations. After the exclusion of clonal hematopoiesis-related mutations, 34 (89.5%) of the 38 patients harbors at least one somatic mutation either from tumor tissues or plasma samples to be monitored longitudinally. ctDNA was detectable in 5 of 14 (36%) post-surgical samples of patients who did not receive adjuvant chemotherapy and in 9 of 18 (50%) post-chemotherapy samples. Up to date, 6 patients have been detected with clinical recurrence and ctDNA analysis identified all 6 recurrences before imaging. Serial ctDNA analyses were able to detect disease recurrence up to 6 months before imaging tests. Furthermore, all patients that were ctDNA negative post-operative or post-chemotherapy showed no signs of clinical relapse. Conclusions: Our current results indicate that ctDNA analysis allows the detection of MRD in CRC patients. The integration of ctDNA analysis with current standard monitoring guidelines holds great promise in early detection of recurrence to allow clinical intervention to be applied promptly.

Impact of older age on clinicopathological and prognostic features of colon cancer in postmenopausal women

To clarify the clinicopathological features of colorectal cancer in older people, systematic studies considering age, sex, and the tumor locus is needed. We focused on colon cancer in postmenopausal women (<70 years, n = 68 vs. ≥70 years, n = 85), and examined the effect of age on clinicopathological features. Rates of medullary carcinoma /mucinous carcinoma were higher and pathological stages at diagnosis were less advanced in patients ≥70 years compared with <70 years. Matching pathological stages, no significant difference in disease-free interval was observed according to age; however, disease-specific survival (DSS) was poorer in patients ≥70 years than <70 years, being significantly different in stage IV cases. Regarding post-metastasis/recurrence (met/rec) cases, chemotherapy and surgery for metastasis were less frequent in those aged ≥70 years than <70 years. Post-met/rec DSS was poorer in ≥70 years, those with microsatellite instability, and those without surgery for met/rec than in each counterpart; however, post-met/rec chemotherapy exhibited no effect. Multivariate analyses revealed that an older age and no surgery for metastasis were independent predictors of disease-specific death. These findings remained after excluding stage IV cases. Older age was a potent risk factor of rapid disease-specific death after met/rec.

Needlescopic surgery for very low rectal cancer with no abdominal skin incision

INTRODUCTION

Needlescopic surgery (NS) is a minimally invasive operation beyond traditional laparoscopic surgery. This study aimed to describe NS for intersphincteric resection (ISR) and abdominoperineal resection (APR) for low rectal cancer without a small abdominal skin incision for extracting the specimen and to evaluate the safety and feasibility of the operation.

METHODS

From January 2011 to April 2016, 36 patients underwent NS for either ISR or APR. By definition, NS for ISR or APR at our institution uses three 3-mm ports and two 5-mm ports at the umbilicus and in the right lower quadrant. The specimen was extracted through the anus or the perineal wound. The feasibility of this operation was determined based on short-term outcomes and pathological findings.

RESULTS

No patients required conversion to open surgery. The mean operation time was 299 minutes, and the mean estimated blood loss was 30 mL. Postoperative complications higher than Clavien-Dindo grade III occurred in 2.8% of patients (n = 1). The median number of harvested lymph nodes was 16 (range, 0-30), and in no case was there a positive circumferential resection margin.

CONCLUSIONS

Needlescopic surgery for ISR or APR is technically safe and feasible for low rectal cancer based on the short-term outcomes and the oncological quality, particularly when compared to conventional laparoscopic surgery as described in previous reports.

Laparoscopic-endoscopic cooperative surgery for ileal lipoma: A case report

This is the first report of laparoscopic-endoscopic cooperative surgery (LECS) for an ileal tumor. A 50-year-old man was admitted to our hospital with a positive fecal occult blood test. Colonoscopy detected a submucosal tumor with intussusception located in the ileum, 10 cm oral from the Bauhin valve. On further examination, he was diagnosed with an ileal lipoma. There were no signs of malignancy. LECS was performed for the ileal tumor. After submucosal elevation by injecting saline solution, a mucosal incision was made circumferentially along the tumor. A full-thickness incision was created endoscopically and laparoscopically on the circumferential mucosal incisional line. The tumor was withdrawn intraluminally by endoscopy. The defect of the ileal wall was closed laparoscopically in an axial direction with linear staplers. Histologically, the tumor was a 25-mm ileal lipoma with negative resection margins and no malignancy.

Laparoscopic multivisceral resection for locally advanced colon cancer: a single-center analysis of short- and long-term outcomes

PURPOSE

We evaluated the technical and oncological safety of laparoscopic multivisceral resection (MVR) in selected patients with locally advanced colon cancer (LACC).

METHODS

We compared the clinical backgrounds, and short- and long-term outcomes of patients who underwent laparoscopic vs. those who underwent open MVR for LACC en bloc at our hospital.

RESULTS

Between January, 2004 and December, 2015, 140 patients underwent MVR of the primary tumor en bloc via laparoscopic surgery (laparoscopic group; LG, n = 69) or open surgery (open group; OG, n = 71). Laparoscopic surgery was selected mainly for tumors that invaded the bladder and abdominal wall. The LG patients had smaller tumors (60 vs. 80 mm, p < 0.001), less blood loss (30 vs. 181 g, p < 0.001), and shorter hospital stays (12 vs. 19 days, p < 0.001) than the OG patients. Open conversion was required for two patients. Postoperative complications and R0 resection were comparable between the groups. Local recurrence occurred in two LG patients and two OG patients. The 5-year cancer-specific survival, disease-free survival, and local disease-free survival of patients with pT4b disease were not significantly different between the LG and OG groups (90.3% vs. 75.2%, 71.2% vs. 67.6%, and 97.1% vs. 94.2%).

CONCLUSION

Although the LG included patients with lower risk, the short- and long-term outcomes were equivalent to those of the OG, which included patients with higher risk.

Pan-Asian adapted ESMO Clinical Practice Guidelines for the management of patients with intermediate and advanced/relapsed hepatocellular carcinoma: a TOS-ESMO initiative endorsed by CSCO, ISMPO, JSMO, KSMO, MOS and SSO

The most recent version of the European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of hepatocellular carcinoma (HCC) was published in 2018, and covered the diagnosis, management, treatment and follow-up of early, intermediate and advanced disease. At the ESMO Asia Meeting in November 2018 it was decided by both the ESMO and the Taiwan Oncology Society (TOS) to convene a special guidelines meeting immediately after the Taiwan Joint Cancer Conference (TJCC) in May 2019 in Taipei. The aim was to adapt the ESMO 2018 guidelines to take into account both the ethnic and the geographic differences in practice associated with the treatment of HCC in Asian patients. These guidelines represent the consensus opinions reached by experts in the treatment of patients with intermediate and advanced/relapsed HCC representing the oncology societies of Taiwan (TOS), China (CSCO), India (ISMPO) Japan (JSMO), Korea (KSMO), Malaysia (MOS) and Singapore (SSO). The voting was based on scientific evidence, and was independent of the current treatment practices, the drug availability and reimbursement situations in the individual participating Asian countries.

Laparoscopic and robotic lateral lymph node dissection for rectal cancer

In the era of neoadjuvant chemoradiotherapy/radiotherapy and total mesorectal excision, overall oncological outcomes after curative resection of rectal cancer are excellent, with local recurrence rates as low as 5–10%. However, lateral nodal disease is a major cause of local recurrence after neoadjuvant chemoradiotherapy/radiotherapy and total mesorectal excision. Patients with lateral nodal disease have a local recurrence rate of up to 30%. The oncological benefits of lateral pelvic lymph node dissection (LPLND) in reducing local recurrence, particularly in the lateral compartment, have been demonstrated. Although LPLND is not standard in Western countries, technical improvements in minimally invasive surgery have resulted in rapid technical standardization of this complicated procedure. The feasibility and short- and long-term outcomes of laparoscopic and robotic LPLND have been reported widely. A minimally invasive approach has the advantages of less bleeding and providing a better surgical view of the deep pelvic anatomy than an open approach. With precise autonomic nerve preservation, postoperative genitourinary dysfunction has been reported to be minimal. We review recent evidence on the management of lateral nodal disease in rectal cancer and technical improvements of LPLND, focusing on laparoscopic and robotic LPLND.

A case of severe megacolon due to acquired isolated hypoganglionosis after low anterior resection for lower rectal cancer

Acquired isolated hypoganglionosis is a rare intestinal neurological disease, which presents in adulthood with the clinical symptoms of chronic constipation. A 39-year-old man underwent laparoscopic low anterior resection and covering ileostomy for locally advanced-rectal cancer. A 6-month course of postoperative adjuvant chemotherapy was completed, followed by closure of the ileostoma. After the closure, he developed severe colitis which required 1-month of hospitalization. Mucosal erosions and pseudo-membrane formation were evident on colonoscopy and severe mucosal damage characterized by infiltration of inflammatory cells and crypt degeneration were pathologically confirmed. Even after the remission of the colitis, he suffered from severe constipation and distention. At 4 years after the stoma closure, he decided to undergo laparoscopic total colectomy. Histopathologically, the nerve fibers and ganglion cells became gradually scarcer from the non-dilated to dilated regions. Immunohistochemical staining examination confirmed that the ganglion cells gradually decreased and became degenerated from the normal to dilated region, thereby arriving at the final diagnosis of isolated hypoganglionosis. The patient recovered without any complications and there has been no evidence of any relapse of the symptoms. We present a case of acquired isolated hypoganglionosis-related megacolon, which required laparoscopic total colectomy, due to severe enterocolitis following stoma closure.

Combination gemcitabine plus S-1 versus gemcitabine plus cisplatin for advanced/recurrent biliary tract cancer: the FUGA-BT (JCOG1113) randomized phase III clinical trial

BACKGROUND

Gemcitabine plus cisplatin (GC) is the standard treatment of advanced biliary tract cancer (BTC); however, it causes nausea, vomiting, and anorexia, and requires hydration. Gemcitabine plus S-1 (GS) reportedly has equal to, or better, efficacy and an acceptable toxicity profile. We aimed to confirm the non-inferiority of GS to GC for patients with advanced/recurrent BTC in terms of overall survival (OS).

PATIENTS AND METHODS

We undertook a phase III randomized trial in 33 institutions in Japan. Eligibility criteria included chemotherapy-naïve patients with recurrent or unresectable BTC, an Eastern Cooperative Oncology Group Performance Status of 0 - 1, and adequate organ function. The calculated sample size was 350 with a one-sided α of 5%, a power of 80%, and non-inferiority margin hazard ratio (HR) of 1.155. The primary end point was OS, while the secondary end points included progression-free survival (PFS), response rate (RR), adverse events (AEs), and clinically significant AEs defined as grade ≥2 fatigue, anorexia, nausea, vomiting, oral mucositis, or diarrhea.

RESULTS

Between May 2013 and March 2016, 354 patients were enrolled. GS was found to be non-inferior to GC [median OS: 13.4 months with GC and 15.1 months with GS, HR, 0.945; 90% confidence interval (CI), 0.78-1.15; P = 0.046 for non-inferiority]. The median PFS was 5.8 months with GC and 6.8 months with GS (HR 0.86; 95% CI 0.70-1.07). The RR was 32.4% with GC and 29.8% with GS. Both treatments were generally well-tolerated. Clinically significant AEs were observed in 35.1% of patients in the GC arm and 29.9% in the GS arm.

CONCLUSIONS

GS, which does not require hydration, should be considered a new, convenient standard of care option for patients with advanced/recurrent BTC.

CLINICAL TRIAL NUMBER

This trial has been registered with the UMIN Clinical Trials Registry (http://www.umin.ac.jp/ctr/index.htm), number UMIN000010667.

Comprehensive Comparative Analysis of Prognostic Value of Systemic Inflammatory Biomarkers for Patients with Stage II/III Colon Cancer

BACKGROUND

Among numerous systemic inflammatory biomarkers, it remains unclear which is the most prognostic for patients with stage II/III colon cancer. We aimed to compare the prognostic significance of systemic inflammatory biomarkers among patients with stage II/III colon cancer.

METHODS

We included 1303 patients with stage II/III colon cancer who underwent potentially curative resection from July 2004 to December 2013. Sixteen systemic inflammatory biomarkers-derived from combinations of neutrophils, lymphocytes, monocytes, platelets, C-reactive protein (CRP), and albumin-were compared to identify the biomarker most associated with overall survival (OS) and disease-free survival (DFS) using receiver operating characteristic (ROC) curve analysis.

RESULTS

Nine inflammatory biomarkers were predictive for OS, among which lymphocyte-to-CRP ratio (LCR), CRP-to-albumin ratio (CAR), neutrophil × CRP, monocyte × CRP, and platelet × CRP were also predictive for DFS. Among these five inflammatory biomarkers, the area under the curve (AUC) value was highest (0.630) for LCR, being significantly higher than that for neutrophil × CRP (P = 0.010), monocyte × CRP (P = 0.007), or platelet × CRP (P = 0.010) for OS. When the prognostic impact of LCR and CAR were analyzed by multivariate analysis, only LCR was an independent predictor of both OS [hazard ratio (HR), 1.77; 95% confidence interval (CI), 1.23-2.60; P = 0.002] and DFS (HR, 1.29; 95% CI, 1.00-1.66; P = 0.048).

CONCLUSIONS

LCR may be the most useful predictive factor for OS and DFS in patients with stage II or III colon cancer.