Differences in Prognosis and Recurrence Patterns Between Ulcerative Colitis-Associated Colorectal Cancer and Sporadic Colorectal Cancer: A Matched-Pair Analysis.

BACKGROUND: Clinicopathological differences exist between ulcerative colitis-associated colorectal cancer (UC-CRC) and sporadic colorectal cancer (S-CRC). However, differences in the prognosis remain controversial, and the reason for these differences remains unclear. We therefore assessed the differences between patients with UC-CRC and S-CRC. PATIENTS AND METHODS: This was a matched-pair analysis of the clinicopathological characteristics and prognosis of patients with UC-CRC and S-CRC who underwent colorectal resection between January 2000 and December 2021 at two institutions. Patients were matched according to age, sex, date of surgery, tumor location, and Union for International Cancer Control (UICC) stage. RESULTS: A total of 5992 patients underwent surgery for CRC at the two institutions, and 288 patients (48 with UC-CRC and 240 with S-CRC) were matched in this study. Patients with UC-CRC underwent more invasive surgery and had a longer operative time than those with S-CRC, but there was no marked difference in postoperative complications or perioperative mortality. Long-term outcomes showed a similar 5-year overall survival (OS) for UC-CRC and S-CRC (86.5% versus 88.8%, p = 0.742); however, in stage 3 patients, patients with UC-CRC had a poorer 5-year OS than those with S-CRC (51.4% versus 83.8%, p = 0.032). The first recurrence sites in stage 3 UC-CRC were peritoneal dissemination followed by the bones, while those in S-CRC were the liver and pulmonary system. CONCLUSIONS: Despite no significant differences in surgical outcomes, patients with UC-CRC had a poorer prognosis than those with S-CRC at stage 3. The recurrence patterns in UC-CRC differed from those in S-CRC, suggesting a possible prognostic difference.

Short-term and Mid-term Outcomes of Indocyanine Green Fluorescence Imaging-Guided Laparoscopic Right-Sided Colectomy: A Propensity Score-Matched Cohort Study.

BACKGROUND: With the use of indocyanine green fluorescence imaging, intraoperative lymphatic flow assessment is possible. However, no report has indicated mid-term outcomes of indocyanine green fluorescence imaging-guided laparoscopic right-sided colectomy. OBJECTIVE: To analyze the mid-term outcomes of indocyanine green fluorescence imaging-guided laparoscopic right-sided colectomy. DESIGN: This was a retrospective, multi-institutional study that used propensity score matching. SETTINGS: We conducted this study within the framework of the Yokohama Clinical Oncology Group in Japan. PATIENTS: A total of 921 patients who underwent laparoscopic right-sided colectomy with lymph node dissection for colon cancer with clinical stages I to III between January 2009 and December 2020 were included. The patients were divided into 2 groups: 233 patients who underwent the lymphatic flow evaluation (indocyanine green group) and 688 patients who did not undergo lymphatic flow evaluation (non-indocyanine green group). MAIN OUTCOMES MEASURES: The 3-year relapse-free survival after laparoscopic right-sided colectomy with and without indocyanine green fluorescence imaging were compared. RESULTS: After propensity score matching, 231 patients were matched in each group. The numbers of dissected central lymph nodes (6 vs 4, p < 0.001), intermediate lymph nodes (7 vs 6, p = 0.03), and the total number of dissected lymph nodes (31 vs 27, p = 0.047) were significantly higher in the indocyanine green group. The median follow-up was 36.9 months. The estimated respective 3-year relapse-free survival and overall survival rates were 88.8% and 94.5% in the indocyanine green group and 89.4% and 94.7% in the non-indocyanine green group ( p = 0.721 and 0.300), respectively, with no difference between the 2 groups. LIMITATIONS: Retrospective design of the study. CONCLUSIONS: Indocyanine green fluorescence imaging-guided laparoscopic right-sided colectomy could increase the number of total, intermediate, and central lymph nodes. However, there was no difference in mid-term outcomes. See Video Abstract. RESULTADOS A CORTO Y MEDIO PLAZO DE LA COLECTOMA LAPAROSCPICA DEL LADO DERECHO GUIADA POR IMGENES DE FLUORESCENCIA CON VERDE DE INDOCIANINA UN ESTUDIO DE COHORTE EMPAREJADO POR PUNTAJE DE PROPENSIN: ANTECEDENTES:Con el uso de imágenes de fluorescencia verde de indocianina, es posible la evaluación del flujo linfático intraoperatorio. Sin embargo, no hay ningún reporte que indique los resultados a medio plazo de la colectomía laparoscópica del lado derecho guiada por imágenes de fluorescencia con verde de indocianina.OBJETIVO:Examinar los resultados a mediano plazo de la colectomía laparoscópica del lado derecho guiada por imágenes de fluorescencia con verde de indocianina.DISEÑO:Estudio multiinstitucional retrospectivo con emparejamiento de puntuación de propensión.CONFIGURACIÓN:Realizado en el marco del Grupo de Oncología Clínica de Yokohama en Japón.PACIENTES:Un total de 921 pacientes sometidos a colectomía laparoscópica del lado derecho con disección de ganglios linfáticos por cáncer de colon con estadio clínico I a III entre enero de 2009 y diciembre de 2020. Los pacientes se dividieron en dos grupos: 233 pacientes sometidos a la evaluación del flujo linfático (grupo con verde de indocianina) y 688 pacientes que no sometidos a la evaluación del flujo linfático (grupo sin verde de indocianina).PRINCIPALES MEDIDAS DE RESULTADOS:Se comparó la supervivencia libre de recaídas a los 3 años después de la colectomía laparoscópica del lado derecho con y sin imágenes de fluorescencia con verde de indocianina.RESULTADOS:Después de emparejar el puntaje de propensión, 231 pacientes fueron emparejados en cada grupo. El número de ganglios linfáticos centrales disecados (6 frente a 4, p < 0,001) y de ganglios linfáticos intermedios (7 frente a 6, p = 0,03) y el número total de ganglios linfáticos disecados (31 frente a 27, p = 0,047) fueron significativamente mayor en el grupo verde de indocianina. La mediana de seguimiento fue de 36,9 meses. Las tasas respectivas estimadas de supervivencia libre de recaídas y supervivencia general a los 3 años fueron del 88,8 % y el 94,5 % en el grupo con verde de indocianina y del 89,4 % y el 94,7 % en el grupo sin verde de indocianina ( p = 0,721 y 0,300), sin diferencias entre los dos grupos.LIMITACIONES:Estudio de diseño retrospectivo.CONCLUSIONES:La colectomía laparoscópica del lado derecho guiada por imágenes de fluorescencia con verde de indocianina puede aumentar el número de ganglios linfáticos totales, intermedios y centrales. Sin embargo, no hubo diferencias en los resultados a medio plazo. (Traducción-Dr. Fidel Ruiz Healy ).

Preoperative risk factors for ileostomy-associated kidney injury in colorectal tumor surgery following ileostomy formation.

PURPOSE: Diverting ileostomy is related to postoperative high-output stoma (HOS) leading to kidney injury. The purpose of our study was to clarify the risk factors for ileostomy-associated kidney injury, which is kidney injury starting after the first operation to ileostomy closure after colorectal tumor surgery with diverting ileostomy. METHODS: Between January 2013 and December 2020, 442 patients who underwent colorectal tumor surgery (cancer, neuroendocrine tumor, and leiomyosarcoma) following diverting ileostomy formation were included. We used the KDIGO (Kidney Disease Improving Global Outcomes) guidelines, which defines the acute kidney injury (AKI) to classify patients with ileostomy-associated kidney injury. The definition of AKI was (i) serum creatinine (sCr) ≥ 0.3 mg/dL or (ii) sCr ≥1.5-fold the preoperative level. Multivariate analyses were performed to identify the independent risk factors for kidney injury. RESULTS: Kidney injury developed in 99/442 eligible patients (22.4%). Patients in the kidney injury group were older age, male sex, high American Society of Anesthesiologists Physical Status Classification System (ASA-PS) score, hypertension, cardiovascular diseases, diabetes. The preoperative hemoglobin, albumin, prognostic nutritional index (PNI), and creatinine clearance (CCr) were lower, and the maximum wound length was more extended than the non-kidney injury group. The median highest daily stoma output was significantly higher in the kidney injury group. The postoperative white blood cell (WBC) and C-reactive protein (CRP) levels were also high in the kidney injury group. The univariate analysis showed older age, male sex, high ASA-PS score, hypertension, cardiovascular diseases, and diabetes were the risk factors for kidney injury. The multivariate analysis revealed that age 70 or older, ASA-PS III/IV, hypertension, and HOS ≥2000 ml/day were independent risk factors for kidney injury. CONCLUSIONS: Surgeons should consider diverting colostomy creation for patients with risk factors such as age 70 or older, ASA-PS III/IV, and hypertension.

Randomized controlled trial evaluating the effect of the use of a laparoscopic lens-cleaning device during laparoscopic colorectal surgery on the multidimensional workload (YCOG1903).

BACKGROUND: OpClear® is a newly developed laparoscopic lens-cleaning device that can be attached to a laparoscope. The present study determined whether or not the use of a OpClear® reduces the multidimensional surgery-specific workload of the operator during laparoscopic colorectal surgery for colorectal cancer compared with the reference technique (warm saline) by a randomized controlled trial. METHODS: Patients diagnosed with colorectal cancer and scheduled for laparoscopic colorectal surgery were randomly allocated to the warm saline arm or Opclear® arm. The primary endpoint was the multidimensional workload of the first operator (value of SURG-TLX). The secondary endpoints were the operative time and total number of lens washes outside the abdominal cavity. RESULTS: Between March 2020 and January 2021, a total of 120 patients were enrolled in this study. A total of 4 patients were excluded from the full analysis set. A total of 116 patients (warm saline arm: 59 patients, Opclear® arm: 57 patients) were therefore analyzed. The baseline factors were well-balanced between the two arms. Regarding SURG-TLX, there was no significant difference in the overall workload between the two arms. Operators in the Opclear® arm required significantly less physical demand than in the warm saline arm (Opclear® arm: 6, warm saline arm: 7; p = 0.046). The operative time was similar between the two arms. The total number of lens washes outside the abdominal cavity in the Opclear® arm was significantly lower than that in the warm saline arm (Opclear® arm: 2, warm saline arm: 10; p < 0.001). CONCLUSIONS: There was no significant difference in the overall workload, but the physical demand and total number of lens washes outside the abdominal cavity were significantly lower in the Opclear® arm than in the warm saline arm. The use of this device may thus help reduce operator stress in terms of physical demand. The study was registered with the Japanese Clinical Trials Registry as UMIN0000038677.

Near-Infrared Imaging Using Indocyanine Green for Laparoscopic Lateral Pelvic Lymph Node Dissection for Clinical Stage II/III Middle-Lower Rectal Cancer: A Propensity Score-Matched Cohort Study.

BACKGROUND: The examination of the efficacy of near-infrared imaging using indocyanine green in laparoscopic lateral pelvic lymph node dissection remains insufficient. OBJECTIVE: The aim of this study was to examine whether near-infrared imaging contributed to an increase in the total number of harvested lateral pelvic lymph nodes in laparoscopic lateral pelvic lymph node dissection. DESIGN: This was a retrospective, multi-institutional study with propensity score matching. SETTINGS: We conducted this study within the framework of the Yokohama Clinical Oncology Group in Japan. PATIENTS: The study population included consecutive patients with middle-low rectal cancer (clinical stage II to III) who underwent laparoscopic lateral pelvic lymph node dissection between January 2013 and February 2018. MAIN OUTCOME MEASURES: The total number of harvested lateral pelvic lymph nodes was compared in laparoscopic lateral pelvic lymph node dissection with and without near-infrared imaging. RESULTS: A total of 172 eligible patients were included; 84 of these patients underwent laparoscopic surgery with near-infrared imaging. After propensity score matching, 58 patients were matched in each of the near-infrared and the non-near-infrared groups. The operation time in the near-infrared group was significantly longer than that in the non-near-infrared group (426 vs 369 min), and the amount of intraoperative blood loss in the near-infrared group was significantly smaller than that in the non-near-infrared group (13 vs 110 mL). The total number of harvested lateral pelvic lymph nodes in the near-infrared group was significantly higher than that in the non-near-infrared group (14 vs 9). There were no significant differences in the postoperative complication rates of the 2 groups. LIMITATIONS: The limitations of the present study include its retrospective design. CONCLUSIONS: This study revealed that laparoscopic lateral pelvic lymph node dissection combined with near-infrared imaging could increase the total number of harvested lateral pelvic lymph nodes without impairing functional preservation. See Video Abstract at http://links.lww.com/DCR/B800.This study was registered with the Japanese Clinical Trials Registry as UMIN000041372 (http://www.umin.ac.jp/ctr/index.htm).IMÁGENES CASI-INFRARROJAS UTILIZANDO VERDE DE INDOCIANINA EN LA DISECCIÓN LAPAROSCÓPICA DE GANGLIOS LINFÁTICOS PÉLVICOS LATERALES EN CASOS DE CÁNCER DE RECTO MEDIO-INFERIOR DE ESTADIO CLÍNICO II / III: ESTUDIO DE COHORTES CON PUNTUACIÓN DE PROPENSIÓNANTECEDENTES:El examen de la eficacia de las imágenes casi-infrarrojas utilizando le verde de indocianina en la disección laparoscópica de los ganglios linfáticos pélvicos laterales sigue siendo insuficiente.OBJETIVO:El objetivo de este estudio fue examinar si las imágenes casi-infrarrojas contribuyeron a un aumento en el número total de ganglios linfáticos pélvicos laterales recolectados durante su disección laparoscópica.DISEÑO:Estudio retrospectivo, multi-institucional con emparejamiento por puntuación de propensión.AJUSTES:Estudio realizado dentro el marco establecido por el Grupo de Oncología Clínica de Yokohama, Japón.PACIENTES:La población estudiada incluyó pacientes consecutivos con cáncer de recto medio-bajo (estadio clínico II a III) que se sometieron a una disección laparoscópica de los ganglios linfáticos pélvicos laterales entre enero de 2013 y febrero de 2018.PRINCIPALES RESULTADOS MEDIDAS:El número total de ganglios linfáticos pélvicos laterales extraídos se comparó en la disección laparoscópica de ganglios linfáticos pélvicos laterales con y sin imágenes casi-infrarrojas.RESULTADOS:Se incluyeron un total de 172 pacientes elegibles; 84 de estos pacientes se sometieron a cirugía laparoscópica con imágenes casi-infrarrojas. Después del emparejamiento por puntuación de propensión, 58 pacientes fueron emparejados en cada uno de los grupos de luz casi-infrarroja y los sin luz. El tiempo de operación en el grupo de luz casi-infrarroja fue significativamente más largo que en el grupo sin luz (426 frente a 369 min), y la cantidad de pérdida de sangre intraoperatoria en el grupo de luz casi-infrarroja fue significativamente menor que en el grupo sin luz (13 frente a 110 ml). El número total de ganglios linfáticos pélvicos laterales recolectados en el grupo de luz casi-infrarroja fue significativamente mayor que en el grupo sin luz (14 frente a 9). No hubo diferencias significativas en las tasas de complicaciones posoperatorias de los dos grupos.LIMITACIONES:Las limitaciones del presente estudio incluyen su diseño retrospectivo.CONCLUSIONES:Este estudio reveló que la disección laparoscópica de los ganglios linfáticos pélvicos laterales combinada con imágenes casi-infrarrojas podría aumentar el número total de ganglios linfáticos pélvicos laterales recolectados sin afectar la preservación funcional. Consulte Video Resumen en http://links.lww.com/DCR/B800. (Traducción-Dr. Xavier Delgadillo)Este estudio se registró en el Registro de Ensayos Clínicos de Japón como UMIN000041372 (http://www.umin.ac.jp/ctr/index.htm).

Preoperative prevalence and risk factors of deep-vein thrombosis in Japanese surgical patients with ulcerative colitis: a retrospective investigational study.

PURPOSE: The purpose of this study was to clarify the perioperative deep-vein thrombosis (DVT) prevalence and its risk factors in surgical ulcerative colitis (UC) patients by comparing the results with those in surgical colorectal cancer (CRC) patients at a high risk of perioperative venous thrombosis. METHODS: This retrospective, observational study included patients who underwent surgery for UC or CRC between January 2013 and October 2019. Consecutive surgical patients with a positive D-dimer assay result (≥ 1.0 µg/ml) underwent lower-extremity venous ultrasonography. The prevalence and risk factors for preoperative DVT were examined in UC patients. RESULTS: A total of 101 UC patients and 593 CRC patients were deemed eligible. Among the D-dimer positive cases, there were no significant differences between the two groups in the preoperative DVT prevalence (UC: 21.8% vs. CRC: 28.8%, p = 0.151), distal type (18.8% vs. 27.2%, p = 0.086), or proximal type (5.9% vs. 4.2%, p = 0.434). Furthermore, multivariate analyses showed that an older age, overweight status, poor ASA status, and a high preoperative dose of steroid were independent risk factors for preoperative DVT in UC surgical patients. CONCLUSIONS: The risk of perioperative thrombosis in UC patients was considered similar to that in CRC, so active thromboprophylaxis should be administered to UC patients while paying attention to bleeding. TRIAL REGISTRATION: This study was registered with the Japanese Clinical Trials Registry as UMIN000042004 ( http://www.umin.ac.jp/ctr/index.htm ).

Relationship between stromal regulatory T cells and the response to neoadjuvant chemotherapy for locally advanced rectal cancer.

BACKGROUND: In addition to the direct power of anticancer drugs, the effectiveness of anticancer therapy depends on the host immune function. The present study investigated whether or not the reduction rate and histological response of preoperative chemotherapy were related to the immune microenvironment surrounding a primary tumor of the rectum. METHODS: Sixty-five patients received preoperative chemotherapy followed by resection from 2012 to 2014; all of these patients were retrospectively analyzed. CD3, CD8, and FoxP3 were immunohistochemically examined as markers for T lymphocytes, cytotoxic T lymphocytes, and regulatory T lymphocytes (Treg), respectively. The correlation between the tumor-infiltrating lymphocyte composition and the tumor reduction rate and histological response to neoadjuvant chemotherapy was investigated. RESULTS: The average tumor reduction rate was 41.5% ± 18.8%. According to RECIST, 47 patients (72.3%) achieved a partial response (PR), and 1 patient (1.5%) achieved a complete response (CR). Eight patients (12.3%) showed a grade 2 histological response, and 2 (3.1%) showed a grade 3 response. A multivariate analysis demonstrated that a low Treg infiltration in stromal cell areas was significantly associated with the achievement of a PR or CR [odds ratio (OR) 7.69; 95% confidence interval (CI) 1.96-33.33; p < 0.01] and a histological grade 2 or 3 response (OR 11.11; 95% CI 1.37-98.04; p = 0.02). CONCLUSION: A low Treg infiltration in the stromal cell areas may be a marker of a good response to neoadjuvant chemotherapy in patients with locally advanced rectal cancer.

The incidence, risk factors, and new prediction score for fluorescence abnormalities of near-infrared imaging using indocyanine green in laparoscopic low anterior resection for rectal cancer.

PURPOSE: Several studies have reported the efficacy of near-infrared imaging using indocyanine green in laparoscopic low anterior resection (LAR), but a detailed examination of its fluorescence abnormalities is still insufficient. The purpose of this study was to clarify the incidence of fluorescence abnormalities and to create a new prediction score in laparoscopic LAR. METHODS: This was a retrospective, multicenter study that included patients with rectal cancer who underwent laparoscopic LAR from September 2014 to November 2018. RESULTS: A total of 336 patients were included. The transection line was changed due to fluorescence abnormalities in 5.4% (18/336) of cases, and the median length of additional resection was 70 mm. Anastomotic leakage of Clavien-Dindo grade ≥ II occurred in 6.0% (20/336). The gender and the intraoperative pre-planned proximal margin (IpPM) were significant factors for fluorescence abnormalities. We devised the fluorescence abnormality prediction score (FAPS) derived from the gender, IpPM, and tumor height from the anal verge (TumorAV). The area under the curve of the FAPS was 0.784 (95% CI: 0.677-0.891). When the cutoff was 4, the sensitivity was 0.833, and the specificity was 0.626. The preoperative pre-planned proximal margin (PpPM) was calculated as follows: PpPM (mm) = 189 (mm) - TumorAV (mm) + 61 × Male (1/0). The proximal margin should be set to be larger than the PpPM to avoid fluorescence abnormalities. CONCLUSION: The incidence of fluorescence abnormalities in laparoscopic LAR was 5.4%. If the FAPS is used, the PpPM may be set from the viewpoint of the blood perfusion. TRIAL REGISTRATION: Japanese Clinical Trials Registry: UMIN000032654 ( http://www.umin.ac.jp/ctr/index.htm ).

A multicenter, propensity score-matched cohort study about short-term and long-term outcomes after laparoscopic versus open surgery for locally advanced rectal cancer.

PURPOSE: This study evaluated the results of laparoscopic surgery (LAP) compared to open surgery (OP) for locally advanced mid-to-lower rectal cancer. METHODS: From February 2008 to December 2014, we collected patient data with clinical stage II/III mid-to-lower rectal cancer who underwent resection with LAP or OP at 13 institutions associated with the Yokohama Clinical Oncology Group (YCOG). The short-term outcomes and long-term prognoses associated with LAP and OP were analyzed after adjusting for the patients' backgrounds using propensity score matching. RESULTS: Among 1091 eligible cases, a propensity score matching with six covariates-age, sex, body mass index, American Society of Anesthesiologists physical status category, tumor location, and clinical stage-extracted 237 cases each for the LAP and OP groups, respectively. After matching, there were no differences in background factors between the two groups except for the presence or absence of preoperative treatment. Operative time was significantly longer in the LAP group than that in the OP group (p < 0.001), while the amount of bleeding and the length of postoperative hospital stay were significantly lower in the LAP group than that in the OP group (p < 0.001 and p = 0.001, respectively). There were no significant differences between groups in the incidence of postoperative complications. The 3-year overall survival and relapse-free survival rates were 90.5% and 88.6% and 78.3% and 71.6% in the LAP and OP groups, respectively, which did not differ significantly. CONCLUSIONS: The short-term outcomes and long-term prognoses of LAP in this cohort study indicated that LAP could be a therapeutic option for locally advanced rectal cancer. TRIAL REGISTRATION: UMIN000040406.

Study protocol: a multicenter randomized controlled trial to evaluate the length of hospital stay of intracorporeal versus extracorporeal anastomosis in laparoscopic colectomy for colon cancer (CONNECT study).

BACKGROUND: Randomized controlled trials (RCTs) comparing intracorporeal anastomosis (IA) and extracorporeal anastomosis (EA) could not prove a significant reduction in postoperative stay and therefore did not provide sufficient evidence of IA. Recently, we reported a new intracorporeal anastomosis method and intracorporeal end-to-end anastomosis (IEEA). However, there have been no studies comparing intracorporeal side-to-side anastomosis (ISSA) to IEEA. PURPOSE: The main purpose of this study is to verify the superiority of IA over EA. The secondary purpose is to compare IEEA with ISSA. METHODS: Patients scheduled to undergo laparoscopic colectomy for colon cancer are recruited to the CONNECT study (multicenter, single-blind, randomized controlled study), cases in which anastomosis by the double-stapling technique is planned will be excluded. The target sample size is set at 300 cases in total, which will be randomized into 3 groups (EA, IEEA, and ISSA) in a 2:1:1 ratio. The primary endpoint is the length of postoperative hospital stay in the IA and EA groups; the secondly endpoint is the anastomotic time in IEEA and ISSA groups. We will also evaluate SF-36 ver.2, EORTC QLQ-C30 ver.3, operator stress using SURG-TLX, and the long-term outcomes, such as 5-year disease-free survival and overall survival. CONCLUSIONS: This RCT will compare the postoperative length of stay between IA and EA in twice the number of cases of previous RCTs. Concurrently, although as a secondary purpose, this will be the first study to compare IEEA and ISSA. TRIAL REGISTRATION: This trial was registered with the UMIN Clinical Trials Registry in September 2020 as UMIN000041565.

The histopathological evaluation based on the indocyanine green fluorescence imaging of regional lymph node metastasis of splenic flexural colon cancer by near-infrared observation.

PURPOSE: The purpose of this study was to investigate the relationship between the fluorescence on indocyanine green fluorescent imaging (ICG-FI) and the histopathological findings of regional lymph node (LN) metastasis of splenic flexural colon cancer. METHODS: From July 2013 to December 2018, consecutive patients with splenic flexural colon cancer with a preoperative diagnosis of N0 who underwent laparoscopic surgery were enrolled. The distribution of cancer sites in metastatic LNs (completely/not completely occupied by metastatic foci) was evaluated with hematoxylin and eosin-stained preparations. We compared the relationship between the distribution of cancer site and fluorescence of paraffin block in metastatic LNs. RESULTS: Seventy-two patients were enrolled, of whom 13 (18.1%) had metastatic LNs. A total of 25 metastatic LNs were evaluated. The median short axis of the occupied LNs was 4.5 mm, which was significantly larger than that of the non-occupied LNs (3.0 mm; p = 0.036). In the near-infrared observation of the paraffin block, the completely occupied LNs showed no fluorescence, regardless of the LN size, but 8 of 10 non-occupied LNs showed fluorescence (p < 0.001). Even the non-occupied LNs that showed fluorescence, the cancer site did not show fluorescence. CONCLUSIONS: The occupied LNs showed no fluorescence, but 80% of the non-occupied LNs showed fluorescence. Even in non-occupied LNs that showed fluorescence, the cancer site did not show fluorescence. This demonstrated LN dissection should not be omitted, even if no fluorescence is noted on intraoperative ICG-FI.

Study protocol: a multicenter randomized controlled trial of the multifaceted workload reduction of the anti-adhesion barrier for diverting ileostomy in laparoscopic rectal surgery, YCOG 2005 (ADOBARRIER study).

BACKGROUND: There are few randomized controlled trials on the efficacy of spray-type anti-adhesion material during diverting ileostomy in laparoscopic rectal cancer surgery. PURPOSE: This study will assess whether or not spraying an anti-adhesion material during diverting ileostomy could reduce the surgeon's multifaceted workload in ileostomy closure. METHODS: Patients with laparoscopic or robotic surgery for rectal cancer scheduled for low anterior resection and diverting ileostomy will be enrolled in the ADOBARRIER study (multicenter, single-blind, randomized controlled trial). The target sample size is set at 120 cases, which will be randomly divided into an anti-adhesion material-using group and a non-using group at a ratio of 1:1. The primary endpoint is the multifaceted workload of the surgeon of ileostomy closure using SURG-TLX between groups with and without usage of the anti-adhesion material during diverting ileostomy construction; the secondly endpoint is the operative time, amount of intraoperative blood loss, degree of adhesions, and extent of intra-abdominal adhesions when the ileostomy is closed. CONCLUSIONS: This RCT will evaluate the efficacy and safety of spray-type anti-adhesion material for diverting ileostomy construction. The results of this study are expected to facilitate decision-making regarding the use of anti-adhesion material. TRIAL REGISTRATION: This trial was registered with the Japan Registry of Clinical Trials (jRCT) in October 2020 as jRCTs032200155.

Oncological outcomes of lateral lymph node dissection (LLND) for locally advanced rectal cancer: is LLND alone sufficient?

BACKGROUND: Lateral lymph node dissection (LLND) has been considered as the standard treatment strategy for locally advanced lower rectal cancer in Japan. Controversy remains around whether all patients require LLND. This study aims to examine the long-term outcomes of patients in which LLND was performed and clarify the value of LLND. METHOD: Consecutive 458 patients with lower rectal cancer who underwent total mesorectal excision (TME) plus LLND from 1992 to 2012 were included. The long-term outcomes and risk factors for recurrent in patients performed TME + LLND were examined. We assessed the impact of LLND on survival using an estimated therapeutic index. RESULTS: The incidence of LLNM was 15.5%. The 5-year RFS and OS rates of patients with LLNM were 40.9% and 47.7%, while patients without LLNM had a good prognosis. The 5-year local recurrence (LR) rate was 9.2%, and independent risk factors for LR were T4 and LLNM. The LR rate of patients with LLNM was high (22.8%). The LLNM rate of the groups with 0, 1, 2, 3, or 4 risk factors (male, tumor location < 4 cm from anal verge, T4, and MLNM) was 3.8%, 9.2%, 18.1%, and 50.0%. The 5-year OS of the groups was 96.2%, 86.1%, 69.7%, and 48.5%. CONCLUSION: Although patients with locally advanced lower rectal cancer who received LLND had a good prognosis, LLND alone was insufficient to control local recurrence in patients with metastatic lateral nodes.

Short- and long-term outcomes of laparoscopic versus open lateral lymph node dissection for locally advanced middle/lower rectal cancer using a propensity score-matched analysis.

BACKGROUND: There are few reports on large-scale trials for the long-term outcomes regarding laparoscopic lateral lymph node dissection (LLND). We evaluated the short- and long-term outcomes of laparoscopic versus open LLND for locally advanced middle/lower rectal cancer using a propensity score-matched analysis. METHODS: From January 2005 to December 2016, consecutive clinical stage II to III middle/lower rectal cancer patients who underwent total mesorectal excision (TME) plus LLND were retrospectively collected at three institutions. Laparoscopic LLND was compared with open LLND for the surgical and oncological outcomes, including the long-term survival, using a propensity score-matched analysis. RESULTS: A total of 325 patients were collected. There were 142 patients who underwent open TME plus LLND (open group) and 183 patients who underwent laparoscopic TME plus LLND (laparoscopic group). A total of 93 patients each were matched to each group. Compared to the open group, the laparoscopic group had a significantly longer operative time (327 vs. 377 min; p = 0.002) but significantly less blood loss (540 vs. 50 ml; p < 0.001), fewer Clavian-Dindo grade ≥ 2 postoperative complications (49.5% vs. 34.4%; p = 0.037) and shorter postoperative hospital stay (18 vs. 14 days; p = 0.008). Furthermore, the rate of urinary retention was significantly lower in the laparoscopic group than in the open group (16.1% vs. 6.5%; p = 0.037). The estimated 3-year overall survival, relapse-free survival, and cumulative incidence of local recurrence were 91.4%, 73.1%, and 3.4% in the open group and 90.3%, 74.2%, and 4.3% in the laparoscopic group (p = 0.879, 0.893, 0.999), respectively. CONCLUSIONS: This study showed that laparoscopic LLND had advantages over an open approach, such as less blood loss, fewer postoperative complications, and a shorter postoperative hospital stay, and the oncologic outcomes were similar to the open approach. Laparoscopic LLND could be a viable standard approach to LLND for advanced middle/lower rectal cancer surgery.

A novel discriminant formula for the prompt diagnosis of strangulated bowel obstruction.

PURPOSES: The diagnosis of strangulated bowel obstruction (SBO) is sometimes difficult. We attempted to create and verify a discriminant formula for use as a diagnostic aid for the early diagnosis of SBO. METHODS: This retrospective study included 97 patients who underwent an operation for SBO from January 2007 to September 2018. First, a discriminant analysis was performed for 73 patients who underwent an operation from January 2007 to December 2015 in order to obtain a formula. Next, we analyzed 34 patients who underwent an operation from January 2016 to September 2018 to verify the formula. RESULTS: The risk factors for SBO included ascites, signs of preperitoneal irritation, and lactate > 1.16 mmol/L. The discriminant formula is as follows: 1.954 × collection of ascites (1 or 0) + 1.239 × peritoneal irritation sign (1 or 0) + 0.378 × lactate - 2.331 (1: positive, 0: negative). The predictive value was as follows: sensitivity, 87.5%; specificity, 64.7%; and predictive accuracy, 73.5%. In patients who presented within 24 h of the onset, the sensitivity was 92.3%, the specificity was 75.0%, and the predictive accuracy was 85.7%. CONCLUSION: Our discriminant formula seems useful for the rapid diagnosis of SBO.

Surgical outcomes of a prospective, phase 2 trial of robotic surgery for resectable right-sided colon cancer (the ROBOCOLO trial).

Aim: We evaluated the safety of robotic surgery for right-sided colon cancer in Japan. Methods: This was a prospective, open-label, single-arm phase II trial conducted at two institutions. Patients ≥20 years old with stage I-III right-sided colon cancer and scheduled for radical resection with ≥D2 lymph node dissection were eligible. The criterion for surgeons was experience performing robot-assisted rectal resection in ≥40 cases. The primary endpoint was the postoperative complication rate ≤30 days after surgery. Results: From August 2021 to February 2023, 42 patients were enrolled; three were excluded, with 39 analyzed as the full analysis set. The median age was 72 years, and the median body mass index was 23.2. The tumor was located in the cecum in 13 cases (33.3%), ascending colon in 20 cases (51.3%), and transverse colon in six cases (15.4%). Ileocolic resection was performed in 17 cases (43.5%) and right hemicolectomy in 22 cases (56.5%), both with D3 lymph node dissection. The median console time was 109 min, and the operative time was 170 min. The mean blood loss was 7.7 mL. Intracorporeal anastomosis was performed in 28 patients (71.8%). There were no conversions and no intraoperative adverse events. The median postoperative stay was 5 days. Postoperative complications occurred in four patients (10.2%; paralytic ileus [n = 3] and pneumonia [n = 1]). All postoperative complications were grade 1 or 2, with no mortalities noted. R0 resection was achieved in all patients. Conclusions: This study demonstrated the safety and feasibility of robotic surgery for right-sided colon cancer.

Effects of neoadjuvant chemotherapy for patients with obstructive colon cancer: A multicenter propensity score-matched analysis (YCOG2101).

Aim: Obstructive colon cancer is locally advanced colon cancer with poor prognosis. However, the effect of neoadjuvant chemotherapy (NAC) on obstructive colon cancer remains unclear. Therefore, this study aimed to investigate the safety and efficacy of NAC in patients with obstructive colon cancer. Methods: From January 2012 to December 2017, we collected patient data for clinical stage II/III obstructive colon cancer at seven Yokohama Clinical Oncology Group (YCOG) institutions. The long-term outcomes of the NAC and non-NAC groups were analyzed retrospectively after adjusting for patients' background characteristics using propensity score matching. Results: Among the 202 eligible patients, propensity score matching extracted 51 patients each for the NAC and non-NAC groups. After matching, the groups showed no marked differences in the background factors. All the patients in the NAC group underwent diverting stoma construction. Nineteen patients (37.3%) experienced grade 3-4 adverse events during NAC. The incidence of postoperative complications was similar between groups. The 5-year progression-free survival rates were 75.8% in the NAC group and 63.0% in the non-NAC group (p = 0.22, log-rank test). The 5-year overall survival rates were 88.5% in the NAC group and 78.8% in the non-NAC group (p = 0.09, log-rank test). Conclusion: Although NAC was feasible for obstructive colon cancer after diverting stoma construction, its effects on long-term outcomes could not be proven.

Potential neuroendocrine differentiation in poorly differentiated colorectal adenocarcinoma: A hidden trait?

Neuroendocrine carcinoma (NEC) of the colon and rectum is a rare malignancy with a poor prognosis that is characterized by distinct clinical and histopathological features that differ significantly from those of more prevalent adenocarcinomas. Poorly differentiated colorectal adenocarcinoma (PDC) is also rare and carries a poor prognosis. Considering the morphological similarities between these two rare, poorly differentiated cancers of the colon and rectum, it is plausible that certain cases of colorectal cancer (CRC) diagnosed as PDC may contain NEC as well. In the present study, cases of CRC that were diagnosed as PDC at our institution were investigated, searching for patients who exhibited NEC characteristics based on the expression of neuroendocrine markers (NEMs), including chromogranin A, synaptophysin and insulinoma-associated 1 (INSM1), and the loss of retinoblastoma 1 (Rb). Of 816 total CRC cases, 74 cases (9.1%) were identified as PDC. These were further divided into 13 (17.5%) cases that were positive for NEMs and others. Of these 13 cases, the expression rates for chromogranin A and synaptophysin were 69.2% each, while that of INSM1 was 100%. Upon re-examination of the 13 PDC cases, two cases were morphologically identified as NEC, including one large- and one small-cell NEC. A total of two cases showed loss of Rb in their PDC lesions. NEM positivity was considered an independent prognostic factor in the 74 PDC cases. Among these cases, some may exhibit characteristics of NEC. Unraveling the molecular mechanisms using CRC that harbors both PDC and NEC will be a task for future research.