Minimally Invasive Surgery: Is It a Risk Factor for Postoperative Peritoneal Metastasis in pT4 Colon Cancer?

BACKGROUND: Performing laparoscopic surgery for T4 colon cancer remains controversial because of concerns about whether its oncologic outcomes are comparable to those of open surgery, and postoperative peritoneal metastasis (PM) has been reported to occur more frequently in laparoscopic colectomy for T4 colon cancer. We investigated whether minimally invasive surgery (MIS) demonstrated a higher PM rate than open surgery and analyzed the risk factors for PM in pT4 colon cancer. METHODS: This study included 392 patients with pT4 colon cancer who underwent curative surgery at a referral hospital between January 2000 and December 2018. Patients with previous neoadjuvant therapy, synchronous malignancy, metastasis, or those who underwent hyperthermic intraperitoneal chemotherapy were excluded. RESULTS: The MIS group had fewer high-risk clinical features, such as tumors too large for endoscope admission or complications like perforation and fistula. The group also exhibited shorter operative time, intraoperative blood loss, multivisceral resection, hospital stay, fewer postoperative complications, smaller tumor size, lower pT4b ratio, and higher pN+ rates. Multivariate analysis revealed that high-risk clinical features, MIS, pT4b, pN+, tumor size < 5 cm, high histological grade, lymphovascular invasion, and postoperative complications were significant risk factors for PM. During the median 59-month follow-up, the 5-year cumulative incidence of PM was elevated in the MIS group (17.5% vs. 8.2%; P = 0.057). No significant differences were observed in the 5-year overall and disease-free survival rates. CONCLUSIONS: Minimally invasive surgery increases the risk of postoperative PM in patients with pT4 colon cancer. Surgeons may require thorough tumor staging and radical resection to prevent PM.

Hepatic arterial infusion in combination with systemic chemotherapy in patients with hepatic metastasis from colorectal cancer: a randomized phase II study - (NCT05103020) - study protocol.

BACKGROUND: Although 80% of patients with metastatic colorectal cancer (CRC) experience liver metastases, only 10-25% undergo resection at the time of diagnosis. Even in initially unresectable conditions, if appropriate treatment is provided, such as surgical conversion through a combination of hepatic arterial infusion (HAI) chemotherapy and systemic chemotherapy (sys-CT), better overall survival can be expected. Therefore, this study aims to evaluate the efficacy of HAI oxaliplatin in combination with sys-CT plus targeted therapy in patients with unresectable CRC with liver-only metastasis. METHODS: This is a single-center, randomized, open-label phase II trial (NCT05103020). Patients with untreated CRC, who have liver-only metastases and for whom liver resection is potentially possible but deemed infeasible at the time of initial diagnosis by a multidisciplinary team, will be eligible. Patients will be randomly assigned in a 1:1 ratio to either the combined HAI oxaliplatin and modified systemic 5-fluorouracil, folinic acid, and irinotecan (FOLFIRI) plus targeted therapy group or the systemic FOLFIRI plus targeted therapy group. Both regimens will be repeated every 2 weeks for a total of 12 cycles. The primary objective of this study is to compare the rate of conversion to liver resection. The surgical conversion rate is expected to increase by 25% with HAI oxaliplatin in combination with sys-CT plus targeted therapy (40% in the experimental arm versus 15% in the control arm) (power, 80%; two-sided alpha-risk, 5%). The secondary objectives include overall survival, progression-free survival, and objective response rate. DISCUSSION: This is the first randomized controlled trial to investigate the efficacy of HAI oxaliplatin in combination with sys-CT plus targeted therapy as first-line treatment from the initial diagnosis in patients with unresectable CRC with liver-only metastasis, aiming to significantly increase the surgical conversion rate. TRIAL REGISTRATION: ClinicalTrials.gov, (NCT05103020). Trial registration date: November 2, 2021.

Pretreatment MRI-detected extramural venous invasion as a prognostic and predictive biomarker for neoadjuvant chemoradiotherapy in non-metastatic rectal cancer: a propensity score matched analysis.

OBJECTIVES: This study evaluated pretreatment magnetic resonance imaging (MRI)-detected extramural venous invasion (pmrEMVI) as a predictor of survival after neoadjuvant chemoradiotherapy (nCRT) in patients with locally advanced rectal cancer (LARC). MATERIALS AND METHODS: Medical records of 1184 patients with rectal adenocarcinoma who underwent TME between January 2011 and December 2016 were reviewed. MRI data were collected from a computerized radiologic database. Cox proportional hazards analysis was used to assess local, systemic recurrence, and disease-free survival risk based on pretreatment MRI-assessed tumor characteristics. After propensity score matching (PSM) for pretreatment MRI features, nCRT therapeutic outcomes according to pmrEMVI status were evaluated. Cox proportional hazards analysis was used to identify risk factors for early recurrence in patients receiving nCRT. RESULTS: Median follow-up was 62.8 months. Among all patients, the presence of pmrEMVI was significantly associated with worse disease-free survival (DFS; HR 1.827, 95% CI 1.285-2.597, p = 0.001) and systemic recurrence (HR 2.080, 95% CI 1.400-3.090, p < 0.001) but not local recurrence. Among patients with pmrEMVI, nCRT provided no benefit for oncological outcomes before or after PSM. Furthermore, pmrEMVI( +) was the only factor associated with early recurrence on multivariate analysis in patients receiving nCRT. CONCLUSIONS: pmrEMVI is a poor prognostic factor for DFS and SR in patients with non-metastatic rectal cancer and also serves as a predictive biomarker of poor DFS and SR following nCRT in LARC. Therefore, for patients who are positive for pmrEMVI, consideration of alternative treatment strategies may be warranted. CLINICAL RELEVANCE STATEMENT: This study demonstrated the usefulness of pmrEMVI as a predictive biomarker for nCRT, which may assist in initial treatment decision-making in patients with non-metastatic rectal cancer. KEY POINTS: • Pretreatment MRI-detected extramural venous invasion (pmrEMVI) was significantly associated with worse disease-free survival and systemic recurrence in patients with non-metastatic rectal cancer. • pmrEMVI is a predictive biomarker of poor DFS following nCRT in patients with LARC. • The presence of pmrEMVI was the only factor associated with early recurrence on multivariate analysis in patients receiving nCRT.

Neoadjuvant chemotherapy versus upfront surgery as the initial treatment for patients with resectable, synchronous colorectal cancer liver metastases.

BACKGROUND: Although perioperative chemotherapy has been the standard treatment for colorectal cancer with resectable liver metastases (CRLM), studies that have compared neoadjuvant chemotherapy (NAC) and upfront surgery, especially in the setting of synchronous metastases are rare. METHODS: We compared perioperative outcomes, overall survival (OS) and overall survival after recurrence (rOS) in a retrospective study of 281 total and 104 propensity score-matched (PSM) patients who underwent curative resection, with or without NAC, for synchronous CRLM, from 2006 to 2017. A Cox regression model was developed for OS. RESULTS: After PSM, 52 NAC and 52 upfront surgery patients with similar baseline characteristics were compared. Postoperative morbidity, mortality, and 5-year OS rate (NAC: 78.9%, surgery: 64.0%; p = 0.102) were similar between groups; however, the NAC group had better rOS (NAC: 67.3%, surgery: 31.5%; p = 0.049). Initial cancer stage (T4, N1-2), poorly differentiated histology, and >1 hepatic metastases were independent predictors of worse OS. Based on these factors, patients were divided into low-risk (≤1 risk factor, n = 115) and high-risk (≥2 risk factors, n = 166) groups. For high-risk patients, NAC yielded better OS than upfront surgery (NAC: 74.5%, surgery: 53.2%; p = 0.024). CONCLUSIONS: Although NAC and upfront surgery-treated patients had similar perioperative outcomes and OS, better postrecurrence survival was shown in patients with NAC. In addition, NAC may benefit patients with worse prognoses; therefore, physicians should consider patient disease risk before initiating treatment to identify patients who are most likely to benefit from chemotherapy.

Postchemoradiation magnetic resonance imaging circumferential resection margin predicts treatment failure after multidisciplinary directed sphincter preservation in low rectal cancer.

BACKGROUND: This study aimed to review the magnetic resonance imaging (MRI) features of patients with low rectal cancer (LRC) undergoing preoperative chemoradiotherapy (CRT) and investigate the risk factors for treatment failure after sphincter preserving surgery following preoperative CRT based on multidisciplinary approach. OBJECTIVES: Patients who underwent standard CRT and sphincter preserving radical surgery for LRC between January 2000 and December 2011 were retrospectively reviewed. Sphincter preservation failure (SPF) was defined as any one of the following: positive pathologic circumferential resection margin, local recurrence, failure to repair ileostomy, or permanent stoma formation due to anastomotic complications. RESULTS: Among the 191 patients, there were no overall significant differences between sphincter preservation success (n = 161) and SPF (n = 30) groups. SPF group showed a higher MRI circumferential resection margins (mrCRM) positive rate before and after CRT (before CRT: 33.3% vs. 16.1%, p = 0.027; after CRT: 23.3% vs. 6.2%, p = 0.002). Multivariate analysis showed that only mrCRM after CRT was associated with SPF (hazard ratio = 4.596, p = 0.005). SPF group showed worse 5-year cancer-specific survival (51% vs. 92.7%, p < 0.001). CONCLUSIONS: MRI-based assessment of the tumor after CRT plays a crucial role in predicting the success and feasibility of sphincter preservation as well as oncological outcomes in patients with LRC.

Difference in medical service use among Korean gastric cancer survivors according to regional healthcare vulnerabilities: a cohort study.

PURPOSE: This study investigated the relationship between medical service use and healthcare vulnerability, pre- and post-gastric cancer diagnosis. Differences between healthcare-vulnerable and healthcare-nonvulnerable regions identified inequities that require intervention. METHODS: This cohort study was done using the National Health Insurance claims data of patients diagnosed with gastric cancer between 2004 and 2013. The Position Value for Relative Comparison Index was used to determine whether the patients lived in a healthcare-vulnerable region. Medical service use was classified into annual outpatient treatment, hospitalization days, and emergency treatment. We used a generalized linear model to which the Poisson distribution was applied and compared regional differences in medical service use. RESULTS: A total of 1797 gastric cancer patients who had survived 5 years post-diagnosis were included in the study, of which 14.2% lived in healthcare-vulnerable regions. The patients in vulnerable regions surviving 5-7 years post-diagnosis had a higher number of outpatient visits than those in nonvulnerable regions. Furthermore, hospitalization days were lesser for patients in vulnerable regions who survived 6 years post-diagnosis than those in nonvulnerable regions; however, this number increased in the seventh year. CONCLUSIONS: Our results suggest that gastric cancer survivors living in healthcare-vulnerable regions have a higher probability of increased medical service use 5 years post-diagnosis compared with patients in nonvulnerable regions, which may significantly increase healthcare disparities over time. Therefore, in the future, additional research is needed to elucidate the causes of the disparities in healthcare use and the results of the differences in health outcomes.

Single-incision laparoscopic surgery compared to conventional laparoscopic surgery for appendiceal mucocele: a series of 116 patients.

BACKGROUND: Although the safety and feasibility of conventional laparoscopic surgery (CLS) for appendiceal mucocele (AM) has been reported, studies on single-incision laparoscopic surgery (SILS) for AM have not been reported. Here, we aimed to compare the perioperative and short-term outcomes between SILS and CLS for AM and to evaluate the oncological safety of SILS. METHODS: We retrospectively analyzed the medical records of patients, diagnosed based on computed tomography findings, who underwent laparoscopic surgery for AM between 2010 and 2018 at one institution. We excluded patients strongly suspected of having malignant lesions and those with preoperative appendiceal perforation. Patients were divided into two groups-CLS and SILS. Pathological outcomes and long-term results were investigated. The median follow-up period was 43.7 (range: 12.3-118.5) months. RESULTS: Ultimately, 116 patients (CLS = 68, SILS = 48) were enrolled. Patient demographic characteristics did not differ between the groups. The preoperative mucocele diameter was greater in the CLS than in the SILS group (3.2 ± 2.9 cm vs. 2.3 ± 1.4 cm, P = 0.029). More extensive surgery (right hemicolectomies and ileocecectomies) was performed in the CLS than in the SILS group (P = 0.014). Intraoperative perforation developed in only one patient per group. For appendectomies and cecectomies, the CLS group exhibited a longer operation time than the SILS group (63.3 ± 24.5 min vs. 52.4 ± 17.3 min, P = 0.014); the same was noted for length of postoperative hospital stay (2.9 ± 1.8 days vs. 1.7 ± 0.6 days, P < 0.001). The most common AM etiology was low-grade appendiceal mucinous neoplasm (71/116 [61.2%] patients); none of the patients exhibited mucinous cystadenocarcinoma. Among these 71 patients, there were 8 patients with microscopic appendiceal perforation or positive resection margins. No recurrence was detected. CONCLUSIONS: SILS for AM is feasible and safe perioperatively and in the short-term and yields favorable oncological outcomes. Despite the retrospective nature of the study, SILS may be suitable after careful selection of AM patients.

Can better surgical outcomes be obtained in the learning process of robotic rectal cancer surgery? A propensity score-matched comparison between learning phases.

BACKGROUND: Although studies of robotic rectal cancer surgery have demonstrated the effects of learning on operation time, comparisons have failed to demonstrate differences in clinicopathological outcomes between unadjusted learning phases. This study aimed to investigate the learning curve of robotic rectal cancer surgery for clinicopathological outcomes and compare surgical outcomes between adjusted learning phases. Study design We enrolled 506 consecutive patients with rectal adenocarcinoma who underwent robotic resection by a single surgeon between 2007 and 2018. Risk-adjusted cumulative sum (RA-CUSUM) for surgical failure was used to analyze the learning curve. Surgical failure was defined as the occurrence of any of the following: conversion to open surgery, severe complications (Clavien-Dindo grade ≥ 3a), insufficient number of harvested lymph nodes (LNs), or R1 resection. Comparisons between learning phases analyzed by RA-CUSUM were performed before and after propensity score matching. RESULTS: In RA-CUSUM analysis, the learning curve was divided into two learning phases: phase 1 (1st-177th cases, n = 177) and phase 2 (178th-506th cases, n = 329). Before matching, patients in phase 2 had deeper tumor invasion and higher rates of positive LNs on pretreatment images and preoperative chemoradiotherapy. After matching, phase 1 (n = 150) and phase 2 (n = 150) patients exhibited similar clinical characteristics. Phase 2 patients had lower rates of surgical failure overall and these components: conversion to open surgery, severe complications, and insufficient harvested LNs. CONCLUSIONS: For robotic rectal cancer surgery, surgical outcomes improved after the 177th case. Further studies by other robotic surgeons are required to validate our results.

Prognosis of Synchronous Colorectal Liver Metastases After Simultaneous Curative-Intent Surgery According to Primary Tumor Location and KRAS Mutational Status.

BACKGROUND: Tumor location and KRAS mutational status have emerged as prognostic factors of colorectal cancer. We aimed to define the prognostic impact of primary tumor location and KRAS mutational status among synchronous colorectal liver metastases (CRLM) patients who underwent simultaneous curative-intent surgery (SCIS). METHODS: We compared the clinicopathologic characteristics and long-term outcomes of 227 patients who underwent SCIS for synchronous CRLM, according to tumor location and KRAS mutational status. We cross-classified tumor location and KRAS mutational status and compared survival outcomes between the four resulting patient groups. RESULTS: Forty-one patients (18.1%) had right-sided (RS) tumors and 186 (81.9%) had left-sided (LS) tumors. One-third of tumors (78/227) harbored KRAS mutations. The KRAS mutant-type (KRAS-mt) was more commonly observed among RS tumors than among LS tumors [21/41 (51.2%) vs. 57/186 (30.6%), p = 0.012]. Median follow-up time was 43.4 months. Patients with RS tumors had shorter survival times than those with LS tumors [median disease-free survival (DFS): RS, 9.9 months vs. LS, 12.1 months, p = 0.003; median overall survival (OS): RS, 49.7 months vs. LS, 88.8 months, p = 0.039]. RS tumors were a negative prognostic factor for DFS [hazard ratio (HR) 1.878, p = 0.001] and OS (HR 1.660, p = 0.060). RS KRAS-mt and LS KRAS wild-type (KRAS-wt) tumors had the worst and best oncological outcomes, respectively. CONCLUSION: Tumor location has a prognostic impact in patients who underwent SCIS for CRLM, and RS KRAS-mt tumors yielded the worst oncological outcome. These results may allow for more tailored multimodality treatments.

Prospective study of oncologic outcomes after laparoscopic modified complete mesocolic excision for non-metastatic right colon cancer (PIONEER study): study protocol of a multicentre single-arm trial.

BACKGROUND: The introduction of complete mesocolic excision (CME) with central vascular ligation (CVL) for right-sided colon cancer has improved the oncologic outcomes. Recently, we have introduced a modified CME (mCME) procedure that keeps the same principles as the originally described CME but with a more tailored approach. Some retrospective studies have reported the favourable oncologic outcomes of laparoscopic mCME for right-sided colon cancer; however, no prospective multicentre study has yet been conducted. METHODS: This study is a multi-institutional, prospective, single-arm study evaluating the oncologic outcomes of laparoscopic mCME for adenocarcinoma arising from the right side of the colon. A total of 250 patients will be recruited from five tertiary referral centres in South Korea. The primary outcome of this study is 3-year disease-free survival. Secondary outcome measures include 3-year overall survival, incidence of surgical complications, completeness of mCME, and distribution of metastatic lymph nodes. The quality of laparoscopic mCME will be assessed on the basis of photographs of the surgical specimen and the operation field after the completion of lymph node dissection. DISCUSSION: This is a prospective multicentre study to evaluate the oncologic outcomes of laparoscopic mCME for right-sided colon cancer. To the best of our knowledge, this will be the first study to prospectively and objectively assess the quality of laparoscopic mCME. The results will provide more evidence about oncologic outcomes with respect to the quality of laparoscopic mCME in right-sided colon cancer. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT03992599 (June 20, 2019). The posted information will be updated as needed to reflect protocol amendments and study progress.

Significance of Radial Margin in Patients Undergoing Complete Mesocolic Excision for Colon Cancer.

BACKGROUND: Comparable to circumferential resection margin in rectal cancer, radial margin is a potential prognostic factor in colon cancer that has just begun to be studied. No previous studies have investigated the influence of radial margin in the context of complete mesocolic excision. OBJECTIVE: This study aimed to examine the impact of radial margin on oncologic outcomes after complete mesocolic excision for colon cancer. DESIGN: We retrospectively reviewed patients with stage I to III colon cancer who underwent curative resection from October 2010 to March 2013. SETTINGS: This study was conducted using the prospective colorectal cancer registry of Severance hospital. PATIENTS: A total of 834 consecutive patients who underwent complete mesocolic excision for colon adenocarcinoma were included. INTERVENTIONS: We assigned patients into 3 groups according to radial margin distance: group A, radial margin ≥2.0 mm; group B, 1.0 ≤ radial margin < 2.0 mm; group C, radial margin <1 mm. MAIN OUTCOMES AND MEASURES: Overall survival and disease-free survival were estimated. RESULTS: On adjusted Cox regression analysis, only group C was predictive of reduced overall survival (HR, 1.90; 95% CI, 1.11-3.25; p = 0.018) and disease-free survival (HR, 1.93; 95% CI, 1.28-2.89; p = 0.001). We thereby defined radial margin threatening as radial margin <1 mm. Postoperative 5-fluorouracil (HR, 0.86; 95% CI, 0.35-2.10; p = 0.743) and FOLFOX (HR, 1.23; 95% CI, 0.57-2.64; p = 0.581) chemotherapy did not affect disease-free survival in patients with radial margin threatening. LIMITATIONS: This study has the limitations inherent in all retrospective, single-institution studies. CONCLUSIONS: Even with complete mesocolic excision, radial margin <1 mm was an independent predictor of survival and recurrence. This finding suggests that special efforts for obtaining a clear radial margin may be necessary in locally advanced colon cancer. See Video Abstract at http://links.lww.com/DCR/B125. IMPORTANCIA DEL MARGEN RADIAL EN PACIENTES SOMETIDOS A ESCISIÓN MESOCÓLICA COMPLETA PARA CÁNCER DEL COLON: Comparable al margen de resección circunferencial en cáncer rectal, el margen radial en cáncer de colon, es un factor pronóstico potencial, que recientemente comienza a estudiarse. Ningún estudio previo ha investigado la influencia del margen radial, en el contexto de la escisión mesocólica completa.Examinar en cáncer de colon, el impacto del margen radial en los resultados oncológicos, después de la escisión mesocólica completa.Revisión retrospectiva de pacientes con cáncer de colon en estadio I-III, sometidos a resección curativa de octubre 2010 a marzo 2013.Este estudio se realizó utilizando un registro prospectivo de cáncer colorrectal del hospital Severance.Se incluyeron un total de 834 pacientes consecutivos con adenocarcinoma de colon, sometidos a escisión mesocólica completa. Dividimos a los pacientes en 3 grupos según la distancia del margen radial: grupo A, margen radial ≥ 2.0 mm; grupo B, 1.0 ≤ margen radial <2.0 mm; grupo C, margen radial <1 mm.Se estimó la supervivencia general y la supervivencia libre de enfermedad.En el análisis de regresión de Cox ajustado, solo el grupo C fue predictivo de supervivencia global reducida (HR, 1.90; IC 95%, 1.11-3.25; p = 0.018) y supervivencia libre de enfermedad (HR, 1.93; IC 95%, 1.28-2.89; p = 0.001). Definimos como margen radial amenazante, un margen radial <1 mm. La quimioterapia posoperatoria con 5-FU (HR, 0,86; IC 95%, 0,35-2,10; p = 0.743) y FOLFOX (HR, 1,23; IC 95%, 0,57-2,64; p = 0,581), no afectó la supervivencia libre de enfermedad en pacientes con riesgo de margen radial.Este estudio tiene limitaciones inherentes a todos los estudios retrospectivos de una sola institución.Aun con la escisión mesocólica completa, el margen radial <1 mm fue un predictor independiente de supervivencia y recurrencia. Este hallazgo sugiere que pueden ser necesarios esfuerzos especiales para obtener un claro margen radial, en cáncer de colon localmente avanzado. Consulte Video Resumen en http://links.lww.com/DCR/B125.

Oncologic safety and bowel function after ultralow anterior resection with or without intersphincteric resection for low lying rectal cancer: Comparative cross sectional study.

BACKGROUND: Despite acceptable oncologic outcomes of sphincter preserving surgeries for low rectal cancer, bowel dysfunction occurs. This study aimed to compare the oncologic and functional bowel outcomes between ultralow anterior resection (ULAR) and intersphincteric resection (ISR) for low rectal cancer. METHODS: One hundred sixty-four patients who underwent ULAR with or without ISR for low rectal cancer between December 2010 and May 2018 were included. The Wexner and Memorial Sloan Kettering Cancer Center (MSKCC) scores were used to evaluate the bowel function of patients. Overall survival (OS) and disease-free survival (DFS) were compared between patients. RESULTS: The ISR group had higher incidence of major fecal incontinence than the ULAR group (75.9% vs 49.3%; P = .016). The median Wexner score decreased from 12 to 9 (P = .062) at 1-year follow-up. However, the frequency and urgency/soilage subscales of MSKCC score improved significantly in the ULAR group. ISR and follow-up interval less than 1-year significantly increased the major incontinence risk. The OS in the ULAR and ISR groups was 91.4% and 91.7%. Whereas the DFS in both groups was 79% and 79.2%, respectively. CONCLUSION: ULAR and ISR are comparable in oncologic outcomes. Severe bowel dysfunctions and major incontinence were noted in ISR group. Careful selection of patients is mandatory.

Survival outcomes after isolated local recurrence of rectal cancer and risk analysis affecting its resectability.

BACKGROUND AND OBJECTIVES: This study aimed to investigate the clinical course and prognostic factors after isolated local recurrence (iLR) and to identify the predictive factors for R0 resection of locally recurrent rectal cancer (LRRC). METHODS: We retrospectively reviewed the medical records of 76 patients with iLR who had undergone radical surgery for a primary tumor from 2003 to 2015. RESULTS: The iLR rate was 2.5%. From 76 patients, 39 patients underwent R0 resection for iLR. Multivariate analysis revealed that initial open surgery, neoadjuvant chemoradiation, and p/ypT ≥ 3 were poor prognostic factors after iLR as regard to the variables related to the primary tumor; and symptom presence at the time of iLR diagnosis, higher fixity, and no chemotherapy after iLR were associated with shorter overall survival after iLR, and R0 resection of LRRC was the only favorable prognostic factor for progression-free survival after iLR as regard to the variables related to LRRC. Higher tumor level, negative pathologic circumferential margin of the primary tumor, and low fixity of LRRC were favorable factors in achieving R0 resection of LRRC. CONCLUSIONS: Early detection of iLR before symptom development, use of chemotherapy after iLR and R0 resection of LRRC should be considered to improve survival outcomes after iLR.

Late anastomotic leakage after anal sphincter saving surgery for rectal cancer: is it different from early anastomotic leakage?

PURPOSE: Although multiple studies have examined anastomotic leakage (AL) after low anterior resection (LAR), their definitions of AL varied, and few have studied late diagnosed AL after surgery. This study aimed to characterize late AL after anal sphincter saving surgery (SSS) for rectal cancer by examining clinical characteristics, risk factors, and management of patients with late AL compared with early AL. METHODS: Data from January 2005 to December 2014 were collected from a total of 1903 consecutive patients who underwent anal sphincter saving surgery for rectal cancer and were retrospectively reviewed. Late AL was defined as AL diagnosed more than 30 days after surgery. Variables and risk factors associated with early and late diagnosed AL were analyzed by multivariate logistic regression. RESULTS: Overall, early, and late rates of AL were 13.7%, 6.7%, and 7%, respectively. Receiving neoadjuvant chemoradiotherapy (nCRT) was a risk factor for developing late AL, but not early AL (OR, 3.032; 95% CI, 1.947-4.722; p < 0.001). Protective ileostomy did not protect against late AL. Among the 134 patients with late AL, 26 (19.4%) were classified as asymptomatic and 108 patients (80.6%) as symptomatic. The most frequent symptomatic complications related to late AL were fistula (42 cases, 39.7%), chronic sinus (33 cases, 31.1%), and stenosis (31 cases, 29.2%). CONCLUSION: Clinical characteristics, risk factors, and management of patients with late AL after SSS were different from early AL. Close attention should be given to consider late AL as the continuation of early AL.

Prediction of transabdominal total mesorectal excision difficulty according to the angle of pelvic floor muscle.

BACKGROUND: Total mesorectal excision (TME) is challenging to perform in a deep, narrow pelvis. While previous studies used pelvimetry to assess bony pelvic structures, there is no consensus on exact definition of deep, narrow pelvis. We hypothesized that the shape of pelvic floor muscle may impact the performance of transabdominal pelvic dissection. We aimed to evaluate which parameters of the shape of pelvic floor muscle impact the difficulty of TME and present a predictive reference value for TME difficulty. METHODS: From January 2015 to December 2015, 85 consecutive patients who had undergone curative resection for middle to lower rectal cancer were retrospectively studied. Pelvimetry was performed using preoperative T2-weighted magnetic resonance imaging. Predictive factor analysis for surgical duration was studied using linear regression. Mann-Whitney U test, comparing surgical duration between two groups classified by predictive factor, was used for the analysis of reference value. RESULTS: Multivariate analysis revealed that body mass index, protective stoma, number of surgeon, and incline angle of pelvic floor muscle (ß) were independent predictors of surgical duration. Test statistics of Mann-Whitney U for the difference in surgical duration between groups above and below a ß of 54° were maximized. CONCLUSIONS: The incline angle of pelvic floor muscle is an independent predictor of surgical duration. In patients with steeper incline of PFM, transabdominal TME is expected to be difficult. This index is novel, but needs to be further validated.

Oncologic Outcomes of Self-Expandable Metallic Stent as a Bridge to Surgery and Safety and Feasibility of Minimally Invasive Surgery for Acute Malignant Colonic Obstruction.

BACKGROUND: Although self-expandable metal stents (SEMS) are widely used as a bridge to surgery (BTS) in patients with malignant colorectal cancer obstruction, there has been some debate about their effect on long-term oncological outcomes. Furthermore, data on the safety and feasibility of minimally invasive surgery (MIS) combined with stent placement are scarce. We aimed to determine the long-term oncological outcomes of SEMS as a BTS, and the short-term outcomes of SEMS used with minimally invasive colorectal surgery. METHODS: Data from patients who were admitted with malignant obstructing colon cancer between January 2006 and December 2015 were retrospectively reviewed; 71 patients underwent direct surgery and 182 patients underwent SEMS placement as a BTS. Long-term and short-term outcomes of the groups were compared. In a subgroup analysis of the BTS group, the short-term outcomes of conventional open surgery and MIS were compared. RESULTS: There were no differences in long-term oncologic outcomes between groups. The primary anastomosis rate was higher in the stent group than in the direct surgery group. In the stent group, postoperative complication rates were lower in the minimally invasive group than in the open surgery group. Time to flatus and time to soft diet resumption were shorter in the minimally invasive group, as was length of hospital stay. CONCLUSIONS: Elective surgery after stent insertion does not adversely affect long-term oncologic outcomes. Furthermore, MIS combined with stent insertion for malignant colonic obstruction is safe and feasible.

Predictive Factors for Bowel Dysfunction After Sphincter-Preserving Surgery for Rectal Cancer: A Single-Center Cross-sectional Study.

BACKGROUND: With increasing rates of sphincter preservation because of advances in preoperative chemoradiation, restoration of bowel continuity has become a main goal of rectal cancer treatment. However, in many patients, postoperative bowel dysfunction negatively affects the quality of life. OBJECTIVE: This study aimed to analyze predictors of bowel dysfunction after sphincter-preserving surgery in patients with rectal cancer. DESIGN: This was a cross-sectional study. SETTINGS: Assessment of bowel dysfunction was conducted between November 2015 and June 2017 at our institution. PATIENTS: A total of 316 patients with rectal cancer who underwent sphincter-preserving surgery between February 2009 and April 2017 and agreed with an interview for assessing bowel dysfunction were included. MAIN OUTCOME MEASURES: Bowel dysfunction was assessed with the Memorial Sloan Kettering Cancer Center Bowel Function Instrument and Wexner score. All the assessments were conducted face-to-face by the same interviewer. RESULTS: The median time interval between the restoration of bowel continuity and assessment was 10 months (interquartile range, 3-37), and the median total Memorial Sloan Kettering Cancer Center and Wexner scores were 65 (interquartile range, 58-73) and 6 (interquartile range, 0-11). The time interval was correlated with the Memorial Sloan Kettering Cancer Center scores (rho, 0.279) and Wexner scores (rho, -0.306). In a multivariate analysis, handsewn anastomosis and short time interval (≤1 year) were independently associated with poor bowel function (Memorial Sloan Kettering Cancer Center score ≤65). A short time interval (≤1 year), preoperative chemoradiation, and ileostomy were independently associated with major fecal incontinence (Wexner ≥8). LIMITATIONS: Selection bias may be inherent. CONCLUSIONS: Bowel function recovers with time after the restoration of bowel continuity. A short time interval, handsewn anastomosis, preoperative chemoradiation, and ileostomy were significantly associated with poor bowel function or major fecal incontinence. Surgeons should discuss postoperative bowel dysfunction and its predictive factors with the patients. See Video Abstract at http://links.lww.com/DCR/A930.

Clinicopathological and biomolecular characteristics of stage IIB/IIC and stage IIIA colon cancer: Insight into the survival paradox.

BACKGROUND: A survival paradox of stage IIB/IIC and IIIA colon cancer has been consistently observed throughout revisions of the TNM system. This study aimed to understand this paradox with clinicopathological and molecular differences. METHODS: Clinicopathological characteristics of patients with pathologically confirmed stage IIB/IIC or IIIA colon cancer were retrospectively reviewed from a database. Publicly available molecular data were retrieved, and intrinsic subtypes were identified and subjected to gene sets enrichment analysis (GSEA). RESULTS: Among the 159 patients included in the clinicopathological analysis, those at stage IIB/IIC had worse 3-year disease-free and overall survival than those at stage IIIA (59.3% vs 91.7%, P < 0.001 and 82.7% vs 98.5%, P < 0.001, respectively), even after adjusting for confounding factors. Data of 95 patients were retrieved from public databases, demonstrating a higher frequency of the microsatellite instable subtype in stage IIB/IIC. The consensus molecular subtype distribution pattern differed between the groups. The GSEA further suggested the protumor inflammatory reaction might be more prominent in stage IIB/IIC. CONCLUSIONS: The survival paradox in colon cancer was confirmed and appears to be a multifactorial phenomenon not attributed to a single clinicopathologic factor. However, the greater molecular heterogeneity in stage IIB/IIC could contribute to the poor prognosis.

C-Reactive Protein Level Predicts Survival Outcomes in Rectal Cancer Patients Undergoing Total Mesorectal Excision After Preoperative Chemoradiation Therapy.

BACKGROUND: Systemic inflammatory response, as measured by C-reactive protein (CRP), is associated with prognosis in various types of human malignancies. However, to the best of our knowledge, the clinical significance of CRP in patients with locally advanced rectal cancer that undergo preoperative chemoradiation has not been investigated in detail. This retrospective study validates CRP as a potential predictive marker for survival outcomes in rectal cancer patients. METHODS: In this study, we enrolled 125 patients that received total mesorectal excision after preoperative chemoradiation for rectal cancer between January 2003 and December 2010. We investigated the association between preoperative CRP and clinicopathological characteristics and assessed the prognostic value of CRP. RESULTS: The median follow-up was 41 months. Elevated CRP showed significant correlation with high histological grade (P = 0.009) and cancer recurrence (P = 0.027). The 5-year disease-free survival and cancer-specific survival were significantly lower in the elevated CRP group (P = 0.001). Moreover, CRP was the strongest predictive factor for cancer-specific survival in multivariate analysis (P = 0.001). In the subgroup analysis, elevated CRP was a significant prognostic factor in patients with node-positive disease (P = 0.025) and was associated with poorer tumor regression (TRG4-5; P = 0.011). CONCLUSIONS: The results of our study suggest that preoperative CRP level shows prognostic significance in rectal cancer patients that have undergone chemoradiation. Therefore, preoperative CRP may help clinicians to identify patients that need additional therapy to reduce systemic failure.

Intraoperative colonoscopy for the assessment and prevention of anastomotic leakage in low anterior resection for rectal cancer.

PURPOSE: Anastomotic leakage (AL) after stapled anastomosis in rectal cancer surgery is a major concern. Various types of intraoperative anastomotic air leakage tests (ALTs) have been proposed to reduce AL. This study aimed to evaluate the impact of intraoperative colonoscopy (IOC) as an intraoperative ALT in low anterior resection for rectal cancer. METHODS: A total of 1266 patients were retrospectively reviewed. Among them, 215 patients who underwent IOC as an ALT in rectal cancer surgery were identified. IOC was performed after anastomosis to visualize the anastomosis line and to perform an ALT by insufflating the neorectum. Propensity score matching was used to match this group at a 1:1 ratio with 215 patients who underwent ALT with a 250-mL bulb irrigation syringe. Anastomotic defects that were found intraoperatively were resolved either by means of primary repair of the anastomotic defect, if possible, or by performing a preventive diverting ileostomy. RESULTS: The patient characteristics, pathologic outcomes, and operation details showed no significant difference between the two groups. Comparison of the AL rate showed a significant difference between the groups (IOC group without intraoperative leaks vs. non-IOC group without intraoperative leaks 4.3 vs. 11.7%, P = 0.007). The incidence of preventive diverting ileostomy because of a positive ALT was significantly higher in the IOC group than in the non-IOC group (10 vs. 2 cases, P = 0.036). CONCLUSION: IOC can be a valuable method for the assessment of stapled anastomosis and has the additional benefit of directly visualizing the anastomosis line.