Clinicopathological significance of microsatellite instability and immune escape mechanism in patients with gastric solid-type poorly differentiated adenocarcinoma.

BACKGROUND: In gastric solid-type poorly differentiated adenocarcinoma (PDA), the role of microsatellite instability and immune escape mechanism remains unclear. The current study aimed to elucidate the clinical significance of mismatch repair (MMR) status, genome profile, C-X-C motif chemokine receptor 2 (CXCR2) expression, and myeloid-derived suppressor cell (MDSC) infiltration in solid-type PDA. METHODS: In total, 102 primary solid-type PDA cases were retrieved, and classified into 46 deficient-MMR (dMMR) and 56 proficient-MMR (pMMR) cases based on immunohistochemistry (IHC) and polymerase chain reaction-based molecular testing results. The mRNA expression profiles (NanoString nCounter Assay) of stage-matched dMMR (n = 6) and pMMR (n = 6) cases were examined. The CXCR2 expression and MDSC infiltration (CD11b- and CD33-positive cells) were investigated via IHC in all solid-type PDA cases. RESULTS: mRNA analysis revealed several differentially expressed genes and differences in biological behavior between the dMMR (n = 46) and pMMR (n = 56) groups. In the multivariate analysis, the dMMR status was significantly associated with a longer disease-free survival (hazard ratio = 5.152, p = 0.002) and overall survival (OS) (hazard ratio = 5.050, p = 0.005). CXCR2-high expression was significantly correlated with a shorter OS in the dMMR group (p = 0.018). A high infiltration of CD11b- and CD33-positive cells was significantly correlated with a shorter OS in the pMMR group (p = 0.022, 0.016, respectively). CONCLUSIONS: dMMR status can be a useful prognostic predictor, and CXCR2 and MDSCs can be novel therapeutic targets in patients with solid-type PDA.

Importance of duodenal stump reinforcement to prevent stump leakage after gastrectomy: a large-scale multicenter retrospective study (KSCC DELICATE study).

BACKGROUND: The significance of reinforcement of the duodenal stump with seromuscular sutures and the effectiveness of reinforced staplers in preventing duodenal stump leakage remain unclear. We aimed to explore the importance of duodenal stump reinforcement and determine the optimal reinforcement method for preventing duodenal stump leakage. METHODS: This retrospective cohort study was conducted between January 1, 2012 and December 31, 2021, with data analyzed between December 1, 2022 and September 30, 2023. This multicenter study across 57 institutes in Japan included 16,475 patients with gastric cancer who underwent radical gastrectomies. Elective open or minimally invasive (laparoscopic or robotic) gastrectomy was performed in patients with gastric cancer. RESULTS: Duodenal stump leakage occurred in 153 (0.93%) of 16,475 patients. The proportions of males, patients aged ≥ 75 years, and ≥ pN1 were higher in patients with duodenal stump leakage than in those without duodenal stump leakage. The incidence of duodenal stump leakage was significantly lower in the group treated with reinforcement by seromuscular sutures or using reinforced stapler than in the group without reinforcement (0.72% vs. 1.19%, p = 0.002). Duodenal stump leakage incidence was also significantly lower in high-volume institutions than in low-volume institutions (0.70% vs. 1.65%, p = 0.047). The rate of duodenal stump leakage-related mortality was 7.8% (12/153). In the multivariate analysis, preoperative asthma and duodenal invasion were identified as independent preoperative risk factors for duodenal stump leakage-related mortality. CONCLUSIONS: The duodenal stump should be reinforced to prevent duodenal stump leakage after radical gastrectomy in patients with gastric cancer.

Transitional dynamics in oncology clinical trials: evaluating the impact of Clinical Trials Act on cooperative groups.

OBJECTIVE: large-scale multicentre clinical trials conducted by cooperative groups have generated a lot of evidence to establish better standard treatments. The Clinical Trials Act was enforced on 1 April 2018, in Japan, and it has remarkably increased the operational burden on investigators, but its long-term impact on cancer cooperative groups is unknown. METHODS: a survey was conducted across the nine major cooperative groups that constitute the Japan Cancer Trials Network to assess the impact of Clinical Trials Act on the number of newly initiated trials from fiscal year (from 1 April to 31 March) 2017 to 2022 and that of ongoing trials on 1 April in each year from 2018 to 2023. RESULTS: the number of newly initiated trials dropped from 38 trials in fiscal year 2017 to 26 trials in fiscal year 2018, surged to 50 trials in fiscal year 2019, but then gradually decreased to 25 trials by fiscal year 2022. Specified clinical trials decreased from 32 trials in fiscal year 2019 to 12 trials in fiscal year 2022. The number of ongoing trials was 220 trials in 2018, peaked at 245 trials in 2020, but then gradually decreased to 219 trials by 2023. The number of specified clinical trials has been in consistent decline. By April 2023, of the 20 ongoing non-specified clinical trials, nine adhered to Clinical Trials Act and 11 followed the Ethical Guidelines for Medical and Health Research Involving Human Subjects. CONCLUSION: the number of multicentre clinical trials in oncology gradually decreased after the Clinical Trials Act's enforcement, which underscores the need for comprehensive amendment of the Clinical Trials Act to streamline the operational process.

Bridging horizons beyond CIRCULATE-Japan: a new paradigm in molecular residual disease detection via whole genome sequencing-based circulating tumor DNA assay.

Circulating tumor DNA (ctDNA) is the fraction of cell-free DNA in patient blood that originates from a tumor. Advances in DNA sequencing technologies and our understanding of the molecular biology of tumors have increased interest in exploiting ctDNA to facilitate detection of molecular residual disease (MRD). Analysis of ctDNA as a promising MRD biomarker of solid malignancies has a central role in precision medicine initiatives exemplified by our CIRCULATE-Japan project involving patients with resectable colorectal cancer. Notably, the project underscores the prognostic significance of the ctDNA status at 4 weeks post-surgery and its correlation to adjuvant therapy efficacy at interim analysis. This substantiates the hypothesis that MRD is a critical prognostic indicator of relapse in patients with colorectal cancer. Despite remarkable advancements, challenges endure, primarily attributable to the exceedingly low ctDNA concentration in peripheral blood, particularly in scenarios involving low tumor shedding and the intrinsic error rates of current sequencing technologies. These complications necessitate more sensitive and sophisticated assays to verify the clinical utility of MRD across all solid tumors. Whole genome sequencing (WGS)-based tumor-informed MRD assays have recently demonstrated the ability to detect ctDNA in the parts-per-million range. This review delineates the current landscape of MRD assays, highlighting WGS-based approaches as the forefront technique in ctDNA analysis. Additionally, it introduces our upcoming endeavor, WGS-based pan-cancer MRD detection via ctDNA, in our forthcoming project, SCRUM-Japan MONSTAR-SCREEN-3.

Impact of surgical proximal and distal margins on the recurrence of resectable colon cancer: a single-center observational cohort study.

PURPOSE: Few studies have investigated the impact of the surgical proximal and distal margins on colon cancer recurrence. We conducted this study to investigate the effect of resection margins on the prognosis of resectable colon cancer. METHODS: We analyzed data on 1458 patients who underwent colorectal resection in our institute between January, 2004 and March, 2020, including 579 patients with resectable colon cancer. The association between the resection margin and recurrence for each oncological status was assessed and the value of the resection length that influenced recurrence was analyzed. RESULTS: Patients who had pT4 colon cancer with margins of more than 7 cm had a trend of fewer recurrences and longer relapse-free survival (RFS) than those with colon cancer of other stages (P = 0.033; hazard ratio [HR], 0.42; 95% confidence interval [CI], 0.20-0.89). Multivariate analysis identified a margin of < 7 cm as an independent risk factor for RFS in patients with pT4 colon cancer (P = 0.023; HR, 2.65; 95% CI 1.013-6.17). No correlation was found between resection margins and recurrence, depending on the extent of lymph node metastasis and tumor location. CONCLUSION: A resection margin of at least 7 cm should be maintained for patients with pT4 colon cancer.

Proposal of "borderline resectable" colorectal liver metastases based on analysis of risk factors for early surgical failure.

PURPOSE: We aimed to define borderline resectable colorectal liver metastases (CRLM) based on the analysis of risk factors for early surgical failure and investigate the efficacy of neoadjuvant chemotherapy in these patients. METHODS: This was a retrospective analysis of a multi-institutional cohort of patients diagnosed with technically resectable CRLM. Early surgical failure within 6 months of liver surgery was defined as ESF6. We classified CRLM into three grades (A, B, and C) according to the definition of the Japanese Society for Cancer of the Colon and Rectum. RESULTS: Among the 249 patients with technically resectable CRLM, 46 (18.5%) developed ESF6. The survival rate of these patients was significantly lower than that of the patients without ESF6. In the multivariate analysis of synchronous CRLM patients, no neoadjuvant chemotherapy, Grade B/C, and Charlson comorbidity index ≥ 3 were independent predictors of ESF6. Among patients with synchronous and Grade B/C CRLM, ESF6 rates, surgical failure-free survival, and overall survival in the neoadjuvant chemotherapy group were significantly better relative to the upfront surgery group. CONCLUSIONS: Patients with synchronous and Grade B/C CRLM are at a high risk of early surgical failure, have a poor long-term prognosis, and can be defined as borderline resectable and good candidates for neoadjuvant chemotherapy.

Clinical practice guidelines for telesurgery 2022 : Committee for the promotion of remote surgery implementation, Japan Surgical Society.

Telesurgery is expected to improve medical access in areas with limited resources, facilitate the rapid dissemination of new surgical procedures, and advance surgical education. While previously hindered by communication delays and costs, recent advancements in information technology and the emergence of new surgical robots have created an environment conducive to societal implementation. In Japan, the legal framework established in 2019 allows for remote surgical support under the supervision of an actual surgeon. The Japan Surgical Society led a collaborative effort, involving various stakeholders, to conduct social verification experiments using telesurgery, resulting in the development of a Japanese version of the "Telesurgery Guidelines" in June 2022. These guidelines outline requirements for medical teams, communication environments, robotic systems, and security measures for communication lines, as well as responsibility allocation, cost burden, and the handling of adverse events during telesurgery. In addition, they address telementoring and full telesurgery. The guidelines are expected to be revised as needed, based on the utilization of telesurgery, advancements in surgical robots, and improvements in information technology.

Evaluation of gastric tube blood flow by multispectral camera and fluorescence angiography.

Background: Evidence regarding the application of the multispectral camera for blood flow measurement is insufficient, and its performance has not been compared with the conventional indocyanine green (ICG) method. Therefore, we retrospectively compared the effectiveness of a new multispectral camera for non-invasive, real-time, quantitative imaging of tissue oxygen (O2) saturation and hemoglobin (Hb) levels and commercially available ICG fluorescence imaging in hemodynamic assessment of gastric tubes in esophagectomy. Methods: Thirty patients who underwent thoracoscopic esophagectomy and gastric tube reconstruction for esophageal cancer were included in this study. The multispectral camera was used to measure tissue O2 saturation and Hb levels. The ICG fluorescence imaging, with the analysis software tool Lumi view, was employed to record ICG luminance changes, with values measured at the anastomotic site. Furthermore, the usefulness of each assessment device was examined using the arterial and venous blood flow indices as cutoff lines for cases with anastomotic failure. Results: In the evaluation of arterial perfusion, anastomotic leak occurred in three of the five (60 %) patients with arterial insufficiency as assessed by the ICG imaging, while anastomotic leakage occurred in all three patients (100 %) who were assessed as having arterial insufficiency by the multispectral camera. In the evaluation of venous perfusion, anastomotic leakage occurred in three of the nine (33.3 %) patients diagnosed with venous stasis by the IC imaging and in three of the five (60 %) patients assessed by the multispectral camera. Conclusion: The multispectral camera assessed gastric tube blood flow more accurately than the ICG fluorescence method.

Association Between Preoperative Osteopenia and Prognosis in Breast Cancer Patients.

BACKGROUND/AIM: Osteopenia, the loss of bone mineral density (BMD), was recently reported as a prognostic factor in various cancers. However, the prognostic significance of preoperative osteopenia in breast cancer remains unclear. This study aimed to clarify the clinical significance of preoperative osteopenia in breast cancer. PATIENTS AND METHODS: We retrospectively analyzed the relationship between osteopenia and clinical factors and prognosis in 532 patients with pathological Stage I-III primary breast cancer between 2009 and 2017. Osteopenia was assessed by measuring the average pixel density (Hounsfield unit) in the midvertebral core of the 11th thoracic vertebra on enhanced preoperative computed tomography. RESULTS: Osteopenia was diagnosed in 186 (35.0%) patients. The recurrence-free survival (RFS) rate was significantly worse in the osteopenia group than in the non-osteopenia group (p=0.0275), but there was no significant difference in overall survival (OS) between the two groups. When evaluated by menopausal status, RFS and OS were significantly worse in the osteopenia group than in the non-osteopenia group (p=0.0094 and p=0.0264, respectively) in premenopausal patients. However, there were no significant differences in RFS and OS between the two groups among postmenopausal patients. In premenopausal patients, osteopenia was an independent prognostic factor for RFS in a multivariate analysis (p=0.0266). CONCLUSION: Preoperative osteopenia was independently associated with recurrence of breast cancer.

A Multicenter Analysis of Short-term and Long-term Outcomes Following Laparoscopic Multivisceral Resection for Advanced Colorectal Cancer.

Background/Aim: Recent research has demonstrated that laparoscopic multivisceral resection (MVR) for advanced colorectal cancer is safe, practicable, and yields satisfactory oncological results, which is in line with the growing usage of laparoscopic surgery. The effectiveness of laparoscopic MVR is still debatable, though. The goal of this study was to compare the short- and long-term results of patients with advanced colorectal cancer treated with open MVR with laparoscopic procedures. Patients and Methods: Data on 3,571 consecutive patients hospitalized at the Kyushu University National Kyushu Cancer Center for colorectal cancer surgery between 2004 and 2020 were gathered retrospectively. In the end, 84 individuals with advanced colorectal cancer who had a colectomy with MVR were examined. We evaluated invasiveness in terms of complications, blood loss, and operating time. Recurrence-free survival rates and overall 5-year survival were among the oncological outcomes. Results: Of the 84 patients examined, 29 underwent laparoscopic treatment, and 55 underwent open treatment. The laparoscopic surgery group experienced shorter hospital stays (15 vs. 18 days, p<0.05) and much less blood loss (median volume: 167 vs. 1,058 g, p<0.005) than the open surgery group. Following the exclusion of patients with stage IV colorectal cancer from the study (groups undergoing laparoscopic surgery, n=25; open surgery, n=38), the groups displayed comparable pathologic results and no discernible variations in either the 5-year overall survival (p=0.87) or recurrence-free survival (p=0.86). Conclusion: In certain individuals with advanced colorectal cancer, a laparoscopic method of manipulation with MVR may be less invasive than an open method without compromising the prognosis.

Immune checkpoint status and oncogenic mutation profiling of rectal cancer after neoadjuvant chemotherapy (KSCC1301-A2).

Aim: Immune checkpoint inhibitors (ICIs) are less effective in mismatch repair (MMR)-proficient (pMMR) colorectal cancers (CRCs) than in MMR-deficient CRCs. Here, we investigated changes in the tumor microenvironment after neoadjuvant chemotherapy (NAC) without radiotherapy in locally advanced rectal cancer (LARC) and the potential of ICIs as therapeutic agents for pMMR CRCs. Methods: This was an ad hoc analysis of a KSCC1301 randomized phase II trial in which patients with untreated resectable LARC were randomly assigned to receive S-1 and oxaliplatin or folinic acid, 5-fluorouracil, and oxaliplatin as NAC. Forty-nine patients were studied in this ad hoc analysis. As a reference cohort, we assessed 25 rectal cancer patients who underwent surgery without NAC outside the randomized trial. Immune checkpoint molecules (ICMs; PD-1, PD-L1, CTLA-4, LAG3), tumor-infiltrating lymphocytes (TILs; CD8, FOXP3), and other related proteins were evaluated by immunohistochemistry. Next-generation sequencing (NGS) using Oncomine™ Comprehensive Assay version 3 was conducted in 23 patients. Results: The expression levels of PD-1, CTLA-4, and LAG3 in the NAC group were significantly higher than in reference patients (p < 0.001). Additionally, the infiltration of CD8+ and FOXP3+ T cells, and the CD8/FOXP3 ratio were significantly higher in the NAC group than in reference patients (p < 0.0001). NGS analysis revealed no specific gene alteration related to TILs or ICMs. Conclusion: We demonstrated changes in the tumor immune microenvironment after NAC in pMMR rectal cancer. NAC was associated with increased expression of ICMs and TILs. Rectal cancer could be susceptible to combined immunotherapy with chemotherapy.

Neoadjuvant Chemotherapy in Patients With T4b or Obstructive Colon Cancer: A Single Center Retrospective Cohort Study.

BACKGROUND/AIM: The efficacy of neoadjuvant chemotherapy (NAC) for colon cancer remains unestablished. This study aimed to investigate the outcomes of NAC in patients with locally advanced T4b or obstructive T4a colon cancers (LACC). PATIENTS AND METHODS: Data of patients with LACC who underwent colon surgery between 2010 and 2022 after NAC at our institution were retrospectively reviewed. Patient characteristics, surgical outcomes, tumor features, and prognosis were analyzed. RESULTS: Among 800 patients with LACC who underwent radical resection, 11 received NAC because of cT4b or cT4a with mechanical obstruction. NAC, administered as a doublet regimen, had a median duration of three months, without grade ≥3 adverse events. R0 resection was achieved in all patients and downstaging was observed in eight patients. One patient developed a postoperative abdominal abscess, and adjuvant chemotherapy was administered to eight patients. Four patients experienced recurrence: liver metastasis in two, and local recurrence in two. Among these, three patients underwent resection of recurrent tumors. Median follow-up was 30 months. CONCLUSION: NAC is feasible for T4b or obstructive T4a colon cancer and may be a treatment option for LACC. Further large-scale studies are required to confirm the efficacy of NAC in these patients.

Ensuring communication redundancy and establishing a telementoring system for robotic telesurgery using multiple communication lines.

Assuring communication redundancy during the interruption and establishing appropriate teaching environments for local surgeons are essential to making robotic telesurgery mainstream. This study analyzes robotic telesurgery with telementoring using standard domestic telecommunication carriers. Can multiple carriers guarantee redundancy with interruptions? Three commercial optical fiber lines connected Hirosaki University and Mutsu General Hospitals, 150 km apart. Using Riverfield, Inc. equipment, Hirosaki had a cockpit, while both Mutsu used both a cockpit and a surgeon's console. Experts provided telementoring evaluating 14 trainees, using objective indices for operation time and errors. Subjective questionnaires addressed image quality and surgical operability. Eighteen participants performed telesurgery using combined lines from two/three telecommunication carriers. Manipulation: over 30 min, lines were cut and restored every three minutes per task. Subjects were to press a switch when noticing image quality or operability changes. Mean time to task completion was 1510 (1186-1960) seconds: local surgeons alone and 1600 (1152-2296) seconds for those under remote instructor supervision, including expert intervention time. There was no significant difference (p = 0.86). The mean error count was 0.92 (0-3) for local surgeons and 0.42 (0-2) with remote instructors. Image quality and operability questionnaires found no significant differences. Results communication companies A, B, and C: the A/B combination incurred 0.17 (0-1) presses of the environment change switch, B/C had 0, and C/A received 0.67 (0-3), showing no significant difference among provider combinations. Combining multiple communication lines guarantees communication redundancy and enables robotic telementoring with enhanced communication security.

Book-Binding Technique in Totally Laparoscopic Distal Gastrectomy with Billroth I Reconstruction: Clinical Results and Outcomes in 188 Patients with Gastric Cancer.

BACKGROUND: Laparoscopic gastrectomy is widely used as a curative treatment for gastric cancer. Although delta-shaped anastomosis is commonly used for Billroth I anastomosis after totally laparoscopic distal gastrectomy (TLDG), it has some drawbacks. The book-binding technique (BBT) was developed as an alternative, and this study aimed to examine its short-term results in 188 consecutive cases. STUDY DESIGN: This retrospective study included patients who underwent BBT reconstruction after TLDG for gastric malignancy between 2011 and 2020. BBT is a technique for intracorporeal gastroduodenostomy, which is a triangular anastomosis with a linear stapler that does not require additional dissection or rotation of the duodenum. The short-term outcomes of BBT reconstruction and postoperative endoscopic findings were analyzed. RESULTS: This study evaluated 188 patients who underwent TLDG and BBT reconstruction. Anastomotic stenosis and leakage occurred in 1.1% and 0.5% of the patients, respectively. The median time to the first diet was 3.1 days, and the median postoperative hospital stay was 11.9 days. BBT anastomoses were performed by 19 surgeons and took an average of 32.8 minutes to complete, with completion times decreasing as the surgical team became more proficient. On endoscopy performed 1 year postoperatively, 5.2% had reflux esophagitis (grade A or higher), 67.8% had gastritis (grade 1 or higher), 37.4% had residual food (grade 1 or higher), and 37.4% had bile reflux (grade 1). CONCLUSIONS: BBT is a safe and feasible method for intracorporeal gastroduodenostomy in TLDG for patients with gastric malignancy and demonstrates good surgical outcomes.

Clinicopathological Impact of High Preoperative CA19-9 in Early-stage Colorectal Cancer: A Single-center Retrospective Cohort Study.

BACKGROUND/AIM: This study examined the clinical significance of very high preoperative carbohydrate antigen 19-9 (CA19-9) levels in patients with early-stage colorectal cancer (CRC). PATIENTS AND METHODS: We retrospectively analyzed the clinicopathological data of patients who underwent curative resection for primary CRC (c-Stage I-III) between 2004 and 2022 in our facility. The patients were classified into three groups according to the preoperative CA19-9 level: normal (≤37.0 U/ml), high (>37.0 to ≤100.0 U/ml), and very high (>100.0 U/ml). RESULTS: Of 971 patients, 885 (91.1%), 67 (6.9%), and 19 (2.0%) had normal, high, and very high CA19-9 levels, respectively. Overall survival (very high vs. normal: p<0.0001, very high vs. high: p=0.01) and recurrence-free survival (very high vs. normal: p<0.0001, very high vs. high: p=0.18) were significantly worse in the very high group. On multivariate analysis including TNM stage, very high preoperative CA19-9 levels were independently associated with worse overall (odds ratio=4.54; 95% confidence interval=2.03-10.16; p=0.0002) and recurrence-free survival (odds ratio=3.49; 95% confidence interval=1.82-6.69; p=0.0002). CONCLUSION: High preoperative CA19-9 levels were associated with poor survival in early-stage CRC. Careful intraoperative observation and close follow-up might be necessary.

Tele-proctoring for minimally invasive surgery across Japan: An initial step toward a new approach to improving the disparity of surgical care and supporting surgical education.

Aim: The aim of this study was to verify the clinical feasibility of tele-proctoring using our ultra-low latency communication system with shared internet access. Methods: Connections between two multiple remote locations at various distances were established through the TELEPRO® tele-proctoring system. The server records the latency between the two locations for tele-proctoring using the annotations. Questionnaires were administered to the surgeons, assistants, and medical staff. Respondents rated the quickness and quality of communication in terms of latency and disturbances in the audio, video, and usefulness of the live telestrations with annotation. Results: Seven hospitals tele-proctored with Sapporo Medical University between January 2021 and September 2022. The median latency of annotation between the two locations ranged from 24.5 to 48.5 ms. No major technological problems occurred, such as streaming interruption, loss of video or audio, poor resolution. The video encoding time was 10 ms, and its decoding time was 0.8 ms. The total latency positively correlated with the distance between two locations (R = 0.55, p < 0.01). The quality of communication regarding latency, disturbance, and surgical education with intraoperative annotative instructions showed similar trends, with perfectly fine being the most common response. No significant differences in surgical quality, educational effect, or social impact were observed between the latency ≥30 and <30 ms groups for whether the size of latency affects surgical education. Conclusion: The feasibility of the tele-proctoring system is expected to be a sustainable approach to help education for young surgeons and surgical supports in rural areas, thereby reducing disparities in health care.

Validity of laparoscopic surgery for lower gastrointestinal perforations.

INTRODUCTION: This study aimed to clarify the validity of laparoscopic surgery for lower gastrointestinal perforation by comparing the clinical outcomes of laparoscopic and open emergency surgery. METHODS: We reviewed the data of patients who underwent surgery for lower gastrointestinal perforation. Patients were categorized into two groups: the laparoscopic group who underwent laparoscopic surgery, and the open group who underwent laparotomy. Clinical and operative outcomes between the two groups were evaluated. RESULTS: A total of 219 patients were included in the study. There were 66 and 153 patients with small bowel and colorectal perforations, respectively. The median operative time in the laparoscopic group was shorter than that in the open group (126 min vs. 146 min, p = .049). The mean amount of intraoperative blood loss was significantly lower in the laparoscopic group (50.4 mL vs. 400.1 mL, p < .001). The incidence of postoperative complication was higher in the open group (20.0% vs. 66.5%, p < .001), especially wound infection (0% vs. 26.3%, p = .002). Median hospital stays were 14 days and 24 days in the laparoscopic and open groups, respectively (p < .001). In the laparoscopic group, hospital mortality was 0%. CONCLUSIONS: The laparoscopic approach for small bowel and colorectal perforation in an emergency setting is a safe procedure in carefully selected patients and may contribute to decreased intraoperative blood loss, shortened hospital stay, and decreased incidence of postoperative complications, especially wound infection.

Colorectal Cancer Recurrence Prediction Using a Tissue-Free Epigenomic Minimal Residual Disease Assay.

PURPOSE: Post-treatment detection of circulating tumor DNA (ctDNA) is strongly predictive of recurrence. Most molecular residual disease (MRD) assays require prior tissue testing to guide ctDNA analysis, resulting in lengthy time to initial results and unevaluable patients. PATIENTS AND METHODS: We assessed a tissue-free assay (Guardant Reveal) that bioinformatically evaluates >20,000 epigenomic regions for ctDNA detection in 1,977 longitudinally collected post-operative plasma samples from 342 patients with resected colorectal cancer (CRC). RESULTS: We observed sensitive and specific detection of MRD associated with clinically meaningful differences in recurrence-free interval at each timepoint evaluated with a median lead time of 5.3 months. Longitudinal sensitivity in stage II or higher colon cancer was 81%. Sensitivity increased with serial measurement and varied by recurrence site: higher for liver (100%) versus lung (53%) and peritoneal (40%). Sensitivity among rectal cancer patients was 60% owing to a high proportion of lung metastases. Specificity was 98.2% among 1,461 post-treatment samples (99.1% among those with follow-up longer than the upper interquartile range of the lead time observed in this study). CONCLUSIONS: Our data demonstrate the potential clinical utility of ctDNA as a tool to improve management of stage II and higher CRC with a methodology that is non-invasive, accessible, and allows for rapid evaluation to inform clinical decisions.

The anti-tumor effect of trifluridine via induction of aberrant mitosis is unaffected by mutations modulating p53 activity.

The fluorinated thymidine analog trifluridine (FTD) is a chemotherapeutic drug commonly used to treat cancer; however, the mechanism by which FTD induces cytotoxicity is not fully understood. In addition, the effect of gain-of-function (GOF) missense mutations of the TP53 gene (encoding p53), which promote cancer progression and chemotherapeutic drug resistance, on the chemotherapeutic efficacy of FTD is unclear. Here, we revealed the mechanisms by which FTD-induced aberrant mitosis and contributed to cytotoxicity in both p53-null and p53-GOF missense mutant cells. In p53-null mutant cells, FTD-induced DNA double-stranded breaks, single-stranded DNA accumulation, and the associated DNA damage responses during the G2 phase. Nevertheless, FTD-induced DNA damage and the related responses were not sufficient to trigger strict G2/M checkpoint arrest. Thus, these features were carried over into mitosis, resulting in chromosome breaks and bridges, and subsequent cytokinesis failure. Improper mitotic exit eventually led to cell apoptosis, caused by the accumulation of extensive DNA damage and the presence of micronuclei encapsulated in the disrupted nuclear envelope. Upon FTD treatment, the behavior of the p53-GOF-missense mutant, isogenic cell lines, generated by CRISPR/Cas9 genome editing, was similar to that of p53-null mutant cells. Thus, our data suggest that FTD treatment overrode the effect on gene expression induced by p53-GOF mutants and exerted its anti-tumor activity in a manner that was independent of the p53 function.

Exploratory Biomarker Analysis Using Plasma Angiogenesis-Related Factors and Cell-Free DNA in the TRUSTY Study: A Randomized, Phase II/III Study of Trifluridine/Tipiracil Plus Bevacizumab as Second-Line Treatment for Metastatic Colorectal Cancer.

BACKGROUND: The TRUSTY study evaluated the efficacy of second-line trifluridine/tipiracil (FTD/TPI) plus bevacizumab in metastatic colorectal cancer (mCRC). OBJECTIVE: This exploratory biomarker analysis of TRUSTY investigated the relationship between baseline plasma concentrations of angiogenesis-related factors and cell-free DNA (cfDNA), and the efficacy of FTD/TPI plus bevacizumab in patients with mCRC. PATIENTS AND METHODS: The disease control rate (DCR) and progression-free survival (PFS) were compared between baseline plasma samples of patients with high and low plasma concentrations (based on the median value) of angiogenesis-related factors. Correlations between cfDNA concentrations and PFS were assessed. RESULTS: Baseline characteristics (n = 65) were as follows: male/female, 35/30; median age, 64 (range 25-84) years; and RAS status wild-type/mutant, 29/36. Patients in the hepatocyte growth factor (HGF)-low and interleukin (IL)-8-low groups had a significantly higher DCR (risk ratio [95% confidence intervals {CIs}]) than patients in the HGF-high (1.83 [1.12-2.98]) and IL-8-high (1.70 [1.02-2.82]) groups. PFS (hazard ratio {HR} [95% CI]) was significantly longer in patients in the HGF-low (0.33 [0.14-0.79]), IL-8-low (0.31 [0.14-0.70]), IL-6-low (0.19 [0.07-0.50]), osteopontin-low (0.39 [0.17-0.88]), thrombospondin-2-low (0.42 [0.18-0.98]), and tissue inhibitor of metalloproteinase-1-low (0.26 [0.10-0.67]) groups versus those having corresponding high plasma concentrations of these angiogenesis-related factors. No correlation was observed between cfDNA concentration and PFS. CONCLUSION: Low baseline plasma concentrations of HGF and IL-8 may predict better DCR and PFS in patients with mCRC receiving FTD/TPI plus bevacizumab, however further studies are warranted. CLINICAL TRIAL REGISTRATION NUMBER: jRCTs031180122.