Hazard function analysis of prognosis after recurrent colorectal cancer.

BACKGROUND AND OBJECTIVES: Mean survival time (MST) is used as the indicator of prognosis in patients with a colorectal cancer (CRC) recurrence. The present study aimed to visualize the changes in death risk after a CRC recurrence using hazard function analysis (HFA) to provide an alternative prognostic indicator to MST. METHODS: The medical records of 725 consecutive patients with a recurrence following R0 radical surgery for CRC were retrospectively reviewed. RESULTS: The five-year, post-recurrence survival rate was 37.8%, and the MST was 3.5 years while the risk of death peaked at 2.9 years post-recurrence. Seven variables were found to predict short-term survival, including the number of metastatic organs ≥ 2, non-surgical treatment for the recurrence, and a short interval before recurrence. In patients with a recurrence in one organ, the MST was four years, the peak time of death predicted by HFA was 2.9 years, and the five-year survival rate was 45.8%. In patients with a surgical resection of the recurrence, the MST was 8 years, the peak time of death was 3.3 years, and the five-year survival rate was 62%. CONCLUSIONS: The present study established a novel method of assessing changes in mortality risk over time using HFA in patients with a CRC recurrence.

Modified neoadjuvant rectal score as a novel prognostic model for rectal cancer patients who underwent chemoradiotherapy.

BACKGROUND: The neoadjuvant rectal score (NAR score) has recently been proposed as a better prognostic model than the conventional TNM classification for rectal cancer patients that have undergone neoadjuvant chemoradiotherapy. We recently developed an apoptosis-detection technique for assessing the viability of residual tumors in resected specimens after chemoradiotherapy. This study aimed to establish an improved prognostic classification by combining the NAR score and the assessment of the apoptosis of residual cancer cells. METHODS: We retrospectively enrolled 319 rectal cancer patients who underwent chemoradiotherapy followed by radical surgery. The recurrence-free survival and overall survival of the four models were compared: TNM stage, NAR score, modified TNM stage by re-staging according to cancer cell viability, and modified NAR score also by re-staging. RESULTS: Downstaging of the ypT stage was observed in 15.5% of cases, whereas only 4.5% showed downstaging of ypN stage. C-index was highest for the modified NAR score (0.715), followed by the modified TNM, TNM, and NAR score. Similarly, Akaike's information criterion was smallest in the modified NAR score (926.2), followed by modified TNM, TNM, and NAR score, suggesting that the modified NAR score was the best among these four models. The overall survival results were similar: C-index was the highest (0.767) and Akaike's information criterion was the smallest (383.9) for the modified NAR score among the four models tested. CONCLUSION: We established a novel prognostic model, for rectal cancer patients that have undergone neoadjuvant chemoradiotherapy, using a combination of apoptosis-detecting immunohistochemistry and neoadjuvant rectal scores.

Differences in the Difficulty of Accessing Various 3-Dimensional Locations Under Mirror-Image Conditions During Laparoscopic Surgery.

BACKGROUND: Laparoscopic colon surgery frequently requires performing maneuvers under mirror-images conditions; the complexity differs depending on the surgical site location in the abdominal cavity. However, no previous reports have examined this. METHODS: Eleven surgeons participated in this study. Operations were performed on 25 points placed at the bottom and sides of a laparoscopic training box under mirror-image conditions. The mean time-point required to operate at each point and variation between surgeons were evaluated. RESULTS: When the right hand was used, time-points to touch the right side-superficial ends were 0.50 to 0.58 and 0.27 to 0.45 for the other sites. With the left hand, time-points to touch the left side-superficial ends were 0.58 to 0.63 and 0.28 to 0.51 for the other sites, indicating that the most difficult manipulation was at the proximal site of the surgical port. The variation in the difficulty according to the spots increased with a decrease in the surgeon's experience (right hand, r=-0.248; left hand, r=-0.491). CONCLUSIONS: In performing laparoscopic surgery under mirror-image conditions, the technical difficulty varies by location, and operating in locations close to the forceps port is the most difficult.

Clinicopathological characteristics of Lynch-like syndrome.

BACKGROUND: Lynch-like syndrome (LLS) has recently been proposed as a third type of microsatellite instability (MSI) tumor after Lynch syndrome (LS) and sporadic MSI colorectal cancer (CRC) without either a germline variant of mismatch repair (MMR) genes or hypermethylation of the MLH1 gene. The present study aimed to clarify and compare the clinicopathological characteristics of LLS with those of the other MSI CRC subtypes. METHODS: In total, 2634 consecutive patients with CRC who underwent surgical resection and subsequently received universal tumor screening (UTS), including MSI analysis were enrolled between January 2008 and November 2019. Genetic testing was performed in patients suspected of having Lynch syndrome. RESULTS: UTS of the cohort found 146 patients with MSI CRC (5.5%). Of these, excluding sporadic MSI CRC, 30 (1.1%) had a diagnosis of LS, and 19 (0.7%) had no germline pathogenic variants of the MMR gene. The CRC type in the latter group was identified as LLS. LLS occurred significantly more often in young patients, was left-sided, involved a KRAS variant and BRAF wild-type, and had a higher concordance rate with the Revised Bethesda Guidelines than sporadic MSI CRC. No significant differences were observed in terms of the clinicopathological factors between LLS and LS-associated MSI CRC; however, LLS had a lower frequency of LS-related neoplasms compared with LS. CONCLUSIONS: Distinguishing clinically between LS and LLS was challenging, but the incidence of neoplasms was higher in LS than in LLS, suggesting the need for different screening and surveillance methods for the two subtypes.

Impact of resection for ovarian metastases from colorectal cancer and clinicopathologic analysis: A multicenter retrospective study in Japan.

Aim: The aim of this study was to clarify the significance of resection of ovarian metastases from colorectal cancer and to identify the clinicopathologic characteristics. Methods: In this multicenter retrospective study, we evaluated data on ovarian metastases from colorectal cancer obtained from patients at 20 centers in Japan between 2000 and 2014. We examined the impact of resection on the prognosis of patients with ovarian metastases and examined prognostic factors. Results: The study included 296 patients with ovarian metastasis. The 3-y overall survival rate was 68.6% for solitary ovarian metastases. In all cases of this cohort, the 3-y overall survival rates after curative resection, noncurative resection, and nonresection were 65.9%, 31.8%, and 6.1%, respectively (curative resection vs noncurative resection [P < 0.01] and noncurative resection vs nonresection [P < 0.01]). In the multivariate analysis of prognostic factors, tumor size of ovarian metastasis (P < 0.01), bilateral ovarian metastasis (P = 0.01), peritoneal metastasis (P < 0.01), pulmonary metastasis (P = 0.04), liver metastasis (P < 0.01), and remnant of ovarian metastasis (P < 0.01) were statistically significantly different. Conclusion: The prognosis after curative resection for solitary ovarian metastases was shown to be relatively favorable as Stage IV colorectal cancer. Resection of ovarian metastases, not only curative resection but also noncurative resection, confers a survival benefit. Prognostic factors were large ovarian metastases, bilateral ovarian metastases, the presence of extraovarian metastases, and remnant ovarian metastases.

Risk of gastric adenoma and adenocarcinoma in patients with familial adenomatous polyposis in Japan: a nationwide multicenter study.

BACKGROUND: Patients with familial adenomatous polyposis (FAP) have an increased risk of developing gastric neoplasms. However, the clinical course of FAP with these gastric lesions has not yet been fully clarified. The present study aimed to clarify the changes in the incidence risk of developing gastric adenoma or gastric cancer during the lifespan of patients with FAP. METHODS: Four hundred forty-three patients with data regarding gastric adenoma and gastric cancer retrospectively registered in a nationwide Japanese multicenter study were enrolled. The cumulative incidences and hazard rates (HRs) of gastric neoplasms were evaluated. RESULTS: The cumulative incidence rates in 50-year-old patients with FAP were 22.8% for gastric adenoma and 7.6% for gastric cancer, respectively. No significant association was found between gastric neoplasms and the colonic phenotype. The peak age for the HR of gastric adenoma was 65 years, with the highest HR (0.043). Regarding the incidence of gastric cancer, the HR increased moderately up to the age of 40 years, but the increase accelerated from the age of 50 years (HR = 0.0067). CONCLUSION: Careful surveillance of the upper gastrointestinal tract in elderly patients with FAP, such as shortening the interval of follow-up according to age, may be helpful for early diagnosis of gastric cancer.

A rare case of localized peliosis hepatis during adjuvant chemotherapy including oxaliplatin mimicking a liver metastasis of colon cancer.

BACKGROUND: Oxaliplatin-based regimens are commonly used as adjuvant chemotherapy following surgery for colorectal cancer. Adverse events associated with oxaliplatin include blue liver, which is caused by sinusoidal dilation and diffuse peliosis hepatis. We report herein a case of localized peliosis hepatis closely resembling a metastatic liver tumor. CASE PRESENTATION: The patient, a 50-year-old male, underwent a robotically assisted colectomy for rectosigmoid colon cancer, which was discovered when hematochezia occurred. The patient received a diagnosis of pStage IIIb and was treated with four courses of CAPOX as adjuvant chemotherapy starting at postoperative month 1. At postoperative month 4, contrast-enhanced computed tomography (CT) of the abdomen revealed a 20-mm, low-density area with heterogeneous internal structure in S6/7 of the liver. Abdominal ultrasound and gadolinium ethoxybenzyl-diethylenetriaminepentaacetic acid-enhanced magnetic resonance imaging (EOB-MRI) findings led to a diagnosis of metastatic liver tumor, for which a laparoscopic partial hepatectomy was performed. The resected lesion was a dark reddish-brown nodule with indistinct margins that appeared to be continuous with the surrounding area. Histopathological analysis revealed severe, localized dilatation of the sinusoids and congestion consistent with the gross nodule. Based on these findings, localized peliosis hepatis associated with oxaliplatin-induced sinusoidal damage was diagnosed. CONCLUSIONS: Localized peliosis hepatis associated with oxaliplatin use can be difficult to distinguish from a metastatic liver tumor on imaging studies.

Prognostic Significance of Enlarged Lymph Nodes in Stage II Colorectal Cancer.

BACKGROUND: Many studies have reported a correlation between lymph node metastasis and prognosis in patients with colorectal cancer. However, the clinical significance of enlarged lymph nodes for prognosis has scarcely been explored. OBJECTIVE: This study aimed to assess the clinical significance of enlarged lymph nodes in stage II colorectal cancer. DESIGN: This is a multicenter retrospective observational study with a median follow-up period of 66.8 months. SETTINGS: Patients' medical records were retrospectively collected from the Japanese Study Group for Postoperative Follow-up of Colorectal Cancer database. PATIENTS: This study included 2212 patients with stage II colorectal cancer who underwent surgical resection between January 2009 and December 2012. Patients were classified into the enlarged lymph node and nonenlarged lymph node groups and their data were compared. MAIN OUTCOME MEASURES: Clinicopathological characteristics and prognoses of the 2 groups were compared. The main outcomes measured were recurrence-free survival and overall survival. RESULTS: The enlarged lymph node group showed significantly better overall survival and recurrence-free survival in pT4b cases but not in pT3 or pT4a cases. In pT4b cases, an enlarged lymph node (HR, 0.53; 95% CI, 0.29-0.98) was an independent prognostic factor for longer recurrence-free survival, whereas a rectal lesion (HR, 3.46; 95% CI, 1.90-6.29) was an independent prognostic factor for shorter recurrence-free survival. An enlarged lymph node was associated with a lower distant recurrence rate (HR, 0.49; 95% CI, 0.26-0.92) and a tendency to correlate with better overall survival (HR, 0.50; 95% CI, 0.22-1.14). LIMITATIONS: The retrospective design may have increased the risk of selection bias. Inadequate information regarding enlarged lymph nodes is another study limitation. CONCLUSIONS: This study showed that enlarged lymph nodes are associated with a favorable prognosis in patients with pT4b stage II colorectal cancer. See Video Abstract at http://links.lww.com/DCR/C246 . IMPORTANCIA PRONSTICA DE LOS GANGLIOS LINFTICOS AGRANDADOS EN EL CNCER COLORRECTAL EN ESTADIO II: ANTECEDENTES:Muchos estudios han informado una correlación entre la metástasis en los ganglios linfáticos y el pronóstico en pacientes con cáncer colorrectal. Sin embargo, apenas se ha explorado la importancia clínica de los ganglios linfáticos agrandados para el pronóstico.OBJETIVO:El objetivo fue evaluar la importancia clínica de los ganglios linfáticos agrandados en el cáncer colorrectal en estadio II.DISEÑO:Este es un estudio observacional retrospectivo multicéntrico con una mediana de seguimiento de 66,8 meses.CONFIGURACIÓN:Los registros médicos de los pacientes se recopilaron retrospectivamente de la base de datos del Grupo de estudio japonés para el seguimiento posoperatorio del cáncer colorrectal.PACIENTES:Incluimos 2212 pacientes con cáncer colorrectal en estadio II que se sometieron a resección quirúrgica entre enero de 2009 y diciembre de 2012. Los pacientes se clasificaron en grupos de ganglios linfáticos agrandados y no agrandados y se compararon sus datos.PRINCIPALES MEDIDAS DE RESULTADO:Se compararon las características clinicopatológicas y los pronósticos de los dos grupos. Los principales resultados medidos fueron la supervivencia sin recurrencia y la supervivencia general.RESULTADOS:El grupo de ganglios linfáticos agrandados mostró una supervivencia general significativamente mejor y una supervivencia libre de recurrencia en los casos pT4b, pero no en los casos pT3 ni pT4a. En los casos de pT4b, el agrandamiento de los ganglios linfáticos (CRI, 0,53; IC 95 %, 0,29-0,98) fue un factor pronóstico independiente para una supervivencia sin recidiva más prolongada, mientras que la lesión rectal (CRI, 3,46; IC 95%, 1,90-6,29) fue un factor pronóstico independiente para RFS más cortos. Los ganglios linfáticos agrandados se relacionaron con una tasa más baja de recurrencia a distancia (CRI, 0,49; IC 95%, 0,26-0,92) y una tendencia a correlacionarse con una mejor supervivencia general (CRI, 0,50; IC 95%, 0,22-1,14).LIMITACIONES:El diseño retrospectivo puede haber aumentado el riesgo de sesgo de selección. La información inadecuada sobre el agrandamiento de los ganglios linfáticos es otra limitación del estudio.CONCLUSIONES:Este estudio mostró que los ganglios linfáticos agrandados están asociados con un pronóstico favorable en pacientes con cáncer colorrectal pT4b en estadio II. Consulte Video Resumen en http://links.lww.com/DCR/C246 . ( Traducción - Dr. Mauricio Santamaria ).

Development of a Diagnostic Artificial Intelligence Tool for Lateral Lymph Node Metastasis in Advanced Rectal Cancer.

BACKGROUND: Metastatic lateral lymph node dissection can improve survival in patients with rectal adenocarcinoma, with or without chemoradiotherapy. However, the optimal imaging diagnostic criteria for lateral lymph node metastases remain undetermined. OBJECTIVE: To develop a lateral lymph node metastasis diagnostic artificial intelligence tool using deep learning, for patients with rectal adenocarcinoma who underwent radical surgery and lateral lymph node dissection. DESIGN: Retrospective study. SETTINGS: Multicenter study. PATIENTS: A total of 209 patients with rectal adenocarcinoma, who underwent radical surgery and lateral lymph node dissection at 15 participating hospitals, were enrolled in the study and allocated to training (n = 139), test (n = 17), or validation (n = 53) cohorts. MAIN OUTCOME MEASURES: In the neoadjuvant treatment group, images taken before pretreatment were classified as baseline images and those taken after pretreatment as presurgery images. In the upfront surgery group, presurgery images were classified as both baseline and presurgery images. We constructed 2 types of artificial intelligence, using baseline and presurgery images, by inputting the patches from these images into ResNet-18, and we assessed their diagnostic accuracy. RESULTS: Overall, 124 patients underwent surgery alone, 52 received neoadjuvant chemotherapy, and 33 received chemoradiotherapy. The number of resected lateral lymph nodes in the training, test, and validation cohorts was 2418, 279, and 850, respectively. The metastatic rates were 2.8%, 0.7%, and 3.7%, respectively. In the validation cohort, the precision-recall area under the curve was 0.870 and 0.963 for the baseline and presurgery images, respectively. Although both baseline and presurgery images provided good accuracy for diagnosing lateral lymph node metastases, the accuracy of presurgery images was better than that of baseline images. LIMITATIONS: The number of cases is small. CONCLUSIONS: An artificial intelligence tool is a promising tool for diagnosing lateral lymph node metastasis with high accuracy. DESARROLLO DE UNA HERRAMIENTA DE INTELIGENCIA ARTIFICIAL PARA EL DIAGNSTICO DE METSTASIS EN GANGLIOS LINFTICOS LATERALES EN CNCER DE RECTO AVANZADO: ANTECEDENTES:Disección de nódulos linfáticos laterales metastásicos puede mejorar la supervivencia en pacientes con adenocarcinoma del recto, con o sin quimiorradioterapia. Sin embargo, aún no se han determinado los criterios óptimos de diagnóstico por imágenes de los nódulos linfáticos laterales metastásicos.OBJETIVO:Nuestro objetivo fue desarrollar una herramienta de inteligencia artificial para el diagnóstico de metástasis en nódulos linfáticos laterales mediante el aprendizaje profundo, para pacientes con adenocarcinoma del recto que se sometieron a cirugía radical y disección de nódulos linfáticos laterales.DISEÑO:Estudio retrospectivo.AJUSTES:Estudio multicéntrico.PACIENTES:Un total de 209 pacientes con adenocarcinoma del recto, que se sometieron a cirugía radical y disección de nódulos linfáticos laterales en 15 hospitales participantes, se inscribieron en el estudio y se asignaron a cohortes de entrenamiento (n = 139), prueba (n = 17) o validación (n = 53).PRINCIPALES MEDIDAS DE RESULTADO:En el grupo de tratamiento neoadyuvante, las imágenes tomadas antes del tratamiento se clasificaron como imágenes de referencia y las posteriores al tratamiento, como imágenes previas a la cirugía. En el grupo de cirugía inicial, las imágenes previas a la cirugía se clasificaron como imágenes de referencia y previas a la cirugía. Construimos dos tipos de inteligencia artificial, utilizando imágenes de referencia y previas a la cirugía, ingresando los parches de estas imágenes en ResNet-18. Evaluamos la precisión diagnóstica de los dos tipos de inteligencia artificial.RESULTADOS:En general, 124 pacientes se sometieron a cirugía solamente, 52 recibieron quimioterapia neoadyuvante y 33 recibieron quimiorradioterapia. El número de nódulos linfáticos laterales removidos en los cohortes de entrenamiento, prueba y validación fue de 2,418; 279 y 850, respectivamente. Las tasas metastásicas fueron 2.8%, 0.7%, y 3.7%, respectivamente. En el cohorte de validación, el área de recuperación de precisión bajo la curva fue de 0.870 y 0.963 para las imágenes de referencia y antes de la cirugía, respectivamente. Aunque tanto las imágenes previas a la cirugía como las iniciales proporcionaron una buena precisión para diagnosticar metástasis en los nódulos linfáticos laterales, la precisión de las imágenes previas a la cirugía fue mejor que la de las imágenes iniciales.LIMITACIONES:El número de casos es pequeño.CONCLUSIÓN:La inteligencia artificial es una herramienta prometedora para diagnosticar metástasis en los nódulos linfáticos laterales con alta precisión. (Traducción-Dr. Aurian Garcia Gonzalez ).

Updating the Predictive Models for Mortality and Morbidity after Low Anterior Resection Based on the National Clinical Database.

INTRODUCTION: We previously developed risk models for mortality and morbidity after low anterior resection using a nationwide Japanese database. However, the milieu of low anterior resection in Japan has undergone drastic changes since then. This study aimed to construct risk models for 6 short-term postoperative outcomes after low anterior resection, i.e., in-hospital mortality, 30-day mortality, anastomotic leakage, surgical site infection except for anastomotic leakage, overall postoperative complication rate, and 30-day reoperation rate. METHODS: This study enrolled 120,912 patients registered with the National Clinical Database, who underwent low anterior resection between 2014 and 2019. Multiple logistic regression analyses were performed to generate predictive models of mortality and morbidity using preoperative information, including the TNM stage. RESULTS: We developed new risk prediction models for the overall postoperative complication and 30-day reoperation rates for low anterior resection, which were absent from the previous version. The concordance indices for each endpoint were 0.82 for in-hospital mortality, 0.79 for 30-day mortality, 0.64 for anastomotic leakage, 0.62 for surgical site infection besides anastomotic leakage, 0.63 for complications, and 0.62 for reoperation. The concordance indices of all four models included in the previous version showed improvement. CONCLUSION: This study successfully updated the risk calculators for predicting mortality and morbidity after low anterior resection using a model based on vast nationwide Japanese data.

Preoperative chemoradiotherapy using tegafur/uracil, oral leucovorin, and irinotecan (TEGAFIRI) followed by oxaliplatin-based chemotherapy as total neoadjuvant therapy for locally advanced rectal cancer: the study protocol for a phase II trial.

BACKGROUND: Total neoadjuvant therapy (TNT) is a novel treatment strategy that is an alternative to preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer (LARC). However, an optimal protocol for TNT has not yet been established. The present study will be an open-label, single-arm, single-center trial to develop a new protocol. METHODS: Thirty LARC patients at high risk of distant metastasis will receive CRT consisting of long-course radiation, concurrent with tegafur/uracil, oral leucovorin, irinotecan (TEGAFIRI), followed by mFOLFOX-6 or CAPOX before undergoing surgery. DISCUSSION: Since previous findings showed a high percentage of grade 3-4 adverse events with the TEGAFIRI regimen for CRT and TNT, the primary outcome of this study will be safety and feasibility. Our regimen for CRT consists of the biweekly administration of irinotecan for good patient compliance. The novel combination approach of this treatment may improve the long-term outcomes of LARC. TRIAL REGISTRATION: Japan Registry of Clinical Trials jRCTs031210660.

Clinical significance of the KRAS G13D mutation in anastomotic recurrence of colorectal cancer.

The genetic risk factors for anastomotic recurrence (AR) after curative surgery for colorectal cancer (CRC) are unclear. The present study is a single-center retrospective observational study that aimed to elucidate the association between the KRAS G13D mutation and AR in CRC. The present study included 21 patients with AR and 67 patients with non-anastomotic local recurrence (NALR) following curative surgery for CRC between January 2005 and December 2019. KRAS G13D mutation status was examined by droplet digital polymerase chain reaction. Data of clinicopathological findings and oncological outcomes were analyzed and compared between the AR group and the matched NALR group. The prevalence of the KRAS G13D mutation was significantly higher in the AR group (AR vs. NALR, 33.3 vs. 4.8%; P=0.047). Comparing the KRAS G13D mutation-positive and KRAS G13D mutation-negative patients in the AR group, there was no significant difference in the time from initial surgery to AR or resection rate of AR; however, all patients with KRAS G13D mutation who underwent resection of AR had subsequent recurrence within 2 years after resection, and overall survival was poor (3-year survival rate: Positive vs. negative, 68.6 vs. 90.9%; P=0.02). The prevalence of the KRAS G13D mutation was significantly higher in patients with AR, and KRAS G13D-mutant patients with AR had a poorer prognosis than those that were negative for the KRAS G13D mutation. In conclusion, postoperative surveillance and treatment strategies should be considered with attention to the possibility of AR and subsequent recurrence in KRAS G13D-mutant patients.

Prediction of lymph node metastasis of well-differentiated rectal neuroendocrine tumours using multiple diagnostic modalities.

AIM: The preoperative prediction of lymph node metastasis of well-differentiated rectal neuroendocrine tumours is highly desirable and useful in defining surgical indication more accurately. We aimed to evaluate lymph node metastasis in rectal neuroendocrine neoplasms using multiple imaging modalities. METHODS: The clinical records and radiological images of 70 patients with well-differentiated rectal neuroendocrine tumours who received treatment at the University of Tokyo Hospital between 2010 and 2022 were retrospectively analysed. The relationship between evaluation by multiple imaging modalities and pathological lymph node metastasis was analysed. RESULTS: The receiver operating characteristic curves showed that a maximum lymph node diameter ≥4 mm on computed tomography and ≥8 mm on magnetic resonance imaging were the optimal predictive factors for lymph node metastasis. Accumulation in the lymph nodes on somatostatin receptor scintigraphy (P = 0.058) and Delle's findings on colonoscopy (P = 0.014) were also significant predictors of pathological lymph node positivity, and combination of multiple modalities was useful. Pathologically, lymphatic (P = 0.0030)/venous (P = 0.0007) invasion were risk factors for lymph node metastasis. CONCLUSIONS: In addition to pathological risk factors, a combination of multiple radiological imaging modalities is useful for predicting lymph node metastasis in well-differentiated rectal neuroendocrine tumours.

Three-dimensional visualization of the total mesorectal excision plane for dissection in rectal cancer surgery and its ability to predict surgical difficulty.

Total mesorectal excision (TME) for rectal cancer is often technically challenging. We aimed to develop a method for three-dimensional (3D) visualization of the TME dissection plane and to evaluate its ability to predict surgical difficulty. Sixty-six patients with lower rectal cancer who underwent robot-assisted surgery were retrospectively analyzed. A 3D TME dissection plane image for each case was reconstructed using Ziostation2. Subsequently, a novel index that reflects accessibility to the deep pelvis during TME, namely, the TME difficulty index, was defined and measured. Representative bony pelvimetry parameters and clinicopathological factors were also analyzed. The operative time for TME was used as an indicator of surgical difficulty. Univariate regression analysis revealed that sex, body mass index, mesorectal fat area, and TME difficulty index were associated with the operative time for TME, whereas bony pelvimetry parameters were not. Multivariate regression analysis found that TME difficulty index (ß = - 0.398, P = 0.0025) and mesorectal fat area (ß = 0.223, P = 0.045) had significant predictability for the operative time for TME. Compared with conventional bony pelvimetry parameters, the TME difficulty index and mesorectal fat area might be more useful in predicting the difficulty of rectal cancer surgery.

Clinicopathological Characteristics of Anastomotic Recurrence After Curative Resection for Colorectal Cancer: Comparison With Nonanastomotic Local Recurrences.

BACKGROUND: Anastomotic recurrence is thought to be caused by implantation of tumor cells to the anastomotic line; however, its risk factors and prognostic significance remain unclear. OBJECTIVE: This study aimed to clarify the risk factors for anastomotic recurrence in colorectal cancer and assess the prognosis in comparison to nonanastomotic local recurrence. DESIGN: A single-center retrospective observational study. SETTINGS: The medical records of the study participants were retrospectively collected from the Department of Surgical Oncology at the University of Tokyo Hospital database. PATIENTS: This study included 1584 patients with colorectal cancer who underwent surgical resection between January 2005 and December 2017. We focused on 15 patients who had an anastomotic recurrence. MAIN OUTCOME MEASURES: The main outcome measures were the risk factors of anastomotic recurrence at the primary resection and prognosis data in comparison to that of nonanastomotic local recurrence. RESULTS: There were 15 patients (0.95%) with anastomotic recurrence and 35 (2.21%) with nonanastomotic local recurrence. Univariate analysis revealed that lymph node metastasis and advanced T stage are the risk factors for anastomotic recurrence. The prognosis of patients with anastomotic recurrence was similar to that of those with nonanastomotic local recurrence who underwent resection. LIMITATIONS: The small number of patients with anastomotic recurrence is a major limitation of this study. Additionally, the retrospective study design may have increased the risk of selection bias. CONCLUSIONS: Lymph node metastasis and advanced T stage were associated with anastomotic recurrence. The prognosis of patients with anastomotic recurrence was similar to that with resected nonanastomotic local recurrence. Thus, surveillance should be carefully continued while considering the poor prognosis of patients with anastomotic recurrence. See Video Abstract at http://links.lww.com/DCR/C92 . CARACTERSTICAS CLINICOPATOLGICAS DE LA RECURRENCIA ANASTOMTICA DESPUS DE LA RESECCIN CURATIVA DEL CNCER COLORRECTAL COMPARACIN CON LAS RECURRENCIAS LOCALES NO ANASTOMTICAS: ANTECEDENTES:Se cree que la recurrencia anastomótica es causada por la implantación de células tumorales en la línea anastomótica; sin embargo, los factores de riesgo asociados y el significado en cuanto a pronóstico siguen sin estar claros.OBJETIVO:Este estudio tuvo como objetivo aclarar los factores de riesgo para la recurrencia anastomótica en el cáncer colorrectal y evaluar el pronóstico en comparación con la recurrencia local no anastomótica.DISEÑO:Un estudio observacional retrospectivo de un solo centro.ESCENARIO:Los registros médicos de los participantes del estudio se recopilaron retrospectivamente de la base de datos del Departamento de Cirugía Oncológica del Hospital de la Universidad de Tokio.PACIENTES:Este estudio incluyó a 1584 pacientes con cáncer colorrectal que se sometieron a resección quirúrgica entre enero de 2005 y diciembre de 2017. Nos enfocamos en 15 pacientes que tuvieron recurrencia anastomótica.PRINCIPALES MEDIDAS DE RESULTADO:Las principales medidas de resultado fueron los factores de riesgo de recurrencia anastomótica en la resección primaria y los datos de pronóstico en comparación con la recurrencia local no anastomótica.RESULTADOS:Hubo 15 pacientes (0.95%) con recurrencia anastomótica y 35 (2.21%) con recurrencia local no anastomótica. El análisis univariable reveló que la metástasis en los ganglios linfáticos y el estadio T avanzado son los factores de riesgo para la recurrencia anastomótica. El pronóstico de los pacientes con recidiva anastomótica fue similar al de aquellos con recidiva local no anastomótica sometidos a resección.LIMITACIONES:El pequeño número de pacientes con recurrencia anastomótica es una limitación importante de este estudio. Además, el diseño retrospectivo del estudio puede haber aumentado el riesgo de sesgo de selección.CONCLUSIONES:La metástasis en los ganglios linfáticos y el estadio T avanzado se asociaron con recurrencia anastomótica. El pronóstico de los pacientes con recidiva anastomótica fue similar al de la recidiva local no anastomótica resecada. Por lo tanto, la vigilancia debe continuarse cuidadosamente considerando el mal pronóstico de los pacientes con recurrencia anastomótica. Consulte Video Resumen en http://links.lww.com/DCR/C92 . (Traducción-Dr. Jorge Silva Velazco ).

Surgical outcomes of robotic, laparoscopic, and open low anterior resection after preoperative chemoradiotherapy for patients with advanced lower rectal cancer.

PURPOSE: We investigated the surgical outcomes of robotic low anterior resection (LAR) for lower rectal cancer after preoperative chemoradiotherapy (pCRT). METHODS: A total of 175 patients with lower rectal cancer who underwent LAR after pCRT between 2005 and 2020 were stratified into open (OS, n = 65), laparoscopic (LS, n = 64), and robotic surgery (RS, n = 46) groups. We compared the clinical, surgical, and pathological results among the three groups. RESULTS: The RS and LS groups had less blood loss than the OS group (p < 0.0001). The operating time in the RS group was longer than in the LS and OS groups (p < 0.0001). The RS group had a significantly longer mean distal margin than the LS and OS groups (25.4 mm vs. 20.7 mm and 20.3 mm, respectively; p = 0.026). There was no significant difference in the postoperative complication rate among the groups. The local recurrence rate in the RS group was comparable to those in the LS and OS groups. CONCLUSION: Robotic LAR after pCRT was performed safely for patients with advanced lower rectal cancer. It provided a longer distal margin and equivalent local control rates.

Optimal diagnostic criteria for lateral lymph node dissection using magnetic resonance imaging: a multicenter prospective study.

BACKGROUND: LLND in cases with suspected lateral lymph node (LLN) metastasis has been focused on as a novel treatment strategy in recent years. However, the optimal indication for LLND in rectal cancer patients has not been determined. This study aimed to establish the optimal indication for lateral lymph node dissection (LLND) in patients with rectal cancer using magnetic resonance imaging (MRI). METHODS: A total of 209 patients with rectal adenocarcinoma who underwent total mesorectal excision and LLND in 13 hospitals were prospectively registered. By matching the sizes of the harvested LNs and those in magnetic resonance imaging (MRI), the pathological outcome of each LN was confirmed one-by-one. Using parameters of the LLNs in MRI, the optimal diagnostic criteria for LLND were established. RESULTS: Of 3241 harvested LLNs, including 83 metastatic nodes, 1010 (31.1%) were visualized on MRI. Although all parameters assessed showed strong correlations with the presence of metastasis, none of these parameters could discriminate metastatic LLNs from non-metastatic nodes with sufficient sensitivity. However, by using the combination of long axis and short/long ratio in pretreatment MRI, we could establish optimal criteria for LLND. The sensitivity and specificity of the criteria for LLN metastasis were 94.3% and 40.2%, respectively. CONCLUSIONS: In conclusion, we established novel criteria for LLND in rectal cancer patients using MRI. Our criteria will be of great clinical use in determining indications for LLND.

Determination of the positional relationship of the second Houston valve and peritoneal reflection using computed tomographic colonography and magnetic resonance imaging.

PURPOSE: The second Houston valve is used as a surrogate for estimating the position of the peritoneal reflection; however, the concordance between the positions of the valve and peritoneal reflection has not been investigated. This study aimed to clarify this positional relationship. METHODS: The second Houston valve and peritoneal reflection positions were assessed using tomographic colonography and magnetic resonance imaging. In total, 117 patients were enrolled in this study. RESULTS: The positions of the second Houston valve and peritoneal reflection were nearly concordant, although the space between them ranged from - 20.7 to 33.9 mm. A peritoneal reflection located further from the anal verge than the second Houston valve was defined as a shallow peritoneal reflection. Male sex, high body weight, and a high body mass index were significantly correlated with a shallower peritoneal reflection, as determined by a univariate analysis (sex: P = 0.0138, weight: P = 0.0097, body mass index: P = 0.0311). A multivariate analysis revealed a significantly shallower peritoneal reflection in males than in females (odds ratio: 2.75, 95% confidence interval: 1.15-6.56, P = 0.023). CONCLUSIONS: The second Houston valve located near the peritoneal reflection can be a useful surrogate marker for estimating its position. In relatively heavy males, the peritoneal reflection is located more cranially than the second Houston valve.

Low Expression of SNAI1 in Lymph Node Metastasis Indicates Delayed Recurrence of Colonic Cancer.

BACKGROUND/AIM: Even though epithelial-mesenchymal transition markers in primary tumors are identified as a helpful indicator of cancer metastasis and prognosis, their expression in lymph node metastases (LNMs) remains poorly described. We aimed to investigate the difference between snail family transcriptional repressor 1 (SNAI1) and E-cadherin expression in primary tumors and LNMs, and how it affects prognosis. PATIENTS AND METHODS: From 2010 to 2014, 127 patients who underwent radical surgery for stage III colonic adenocarcinoma without preoperative treatment were retrospectively reviewed for SNAI1 and E-cadherin expression in primary tumors and LNMs. RESULTS: High SNAI1 expression was found in 76% and 70% of primary tumors and LNMs, respectively, and low E-cadherin expression was found in 73% and 84%, respectively. High expression of SNAI1 in LNMs significantly correlated with poor overall and relapse-free survival rates. Even though the rate of liver metastasis at 5 years was similar for the groups with high and low SNAI1 expression in LNMs, the incidence in the group with low SNAI1 expression in the second year was higher than that in the first year (33% vs. 17%), whilst in the group with high SNAI1 expression, the incidence in the first year was higher than in the second year (71% vs. 29%). The rate of recurrence of lung metastasis was significantly lower when SNAI1 expression in LNMs was low (p=0.031). CONCLUSION: Low expression of SNAI1 in LNMs of colonic adenocarcinoma may indicate delayed recurrence in the liver and lung.

Giant filiform polyposis with high-grade dysplasia: A case report and review of the literature.

Introduction and importance: Filiform polyposis, a rare condition also referred to as inflammatory polyposis or pseudopolyposis, is commonly observed in cases of inflammatory bowel disease, such as ulcerative colitis or Crohn's disease. It is generally considered a benign tumour characterised by multiple finger-like projections that are mostly observed in the transverse and descending colon. Case presentation: A 69-year-old woman with a history of ulcerative colitis for 18 years who underwent temporary decompression ileostomy for large bowel obstruction at another hospital was referred to our institution for further investigation. Abdominal computed tomography revealed bowel wall thickening of the transverse colon, and colonoscopy revealed stenosis in the hepatic flexure obstructing the endoscope. Although several biopsies of the tumour showed no malignancy, laparoscopic subtotal colectomy with lymph node dissection was performed. Histopathological findings revealed localised filiform polyposis with dysplasia. Clinical discussion: Filiform polyposis has been considered a benign inflammatory polyp without any risk of dysplasia. We accumulated previous cases of giant filiform polyposis and reviewed their characteristics. The presented case of filiform polyposis with ulcerative colitis complicated with high-grade dysplasia highlights the importance of considering malignancy in patients with filiform polyposis. Conclusion: In cases of giant filiform polyposis, even when no malignancy is detected, surgical resection should be considered for the possibility of a malignant component of dysplasia.