Effects of prior endoscopic resection on recurrence in patients with T1 colorectal cancer who underwent radical surgery.

PURPOSE: Endoscopic resection (ER) is a reliable treatment for early colorectal cancer without lymph node metastasis. We aimed to examine the effects of ER performed prior to T1 colorectal cancer (T1 CRC) surgery by comparing long-term survival after radical surgery with prior ER to that after radical surgery alone. METHODS: This retrospective study included patients who underwent surgical resection of T1 CRC at the National Cancer Center, Korea, between 2003 and 2017. All eligible patients (n = 543) were divided into primary and secondary surgery groups. To ensure similar characteristics between the groups, 1:1 propensity score matching was used. Baseline characteristics, gross and histological features, along with postoperative recurrence-free survival (RFS) between the two groups were compared. Cox proportional hazard model was used to identify the risk factors affecting recurrence after surgery. Cost analysis was performed to examine the cost-effectiveness of ER and radical surgeries. RESULTS: No significant differences were observed in 5-year RFS between the two groups in matched data (96.9% vs. 95.5%, p = 0.596) and in the unadjusted model (97.2% vs. 96.8%, p = 0.930). This difference was also similar in subgroup analyses based on node status and high-risk histologic features. ER before surgery did not increase the medical costs of radical surgery. CONCLUSION: ER prior to radical surgery did not affect the long-term oncologic outcomes of T1 CRC or significantly increased the medical costs. Attempting ER first for suspected T1 CRC would be a good strategy to avoid unnecessary surgery without concerns of worsening cancer-related prognosis.

Safety of early surgery after self-expandable metallic stenting for obstructive left-sided colorectal cancer.

BACKGROUND: Self-expanding metallic stenting (SEMS) is usual for the temporary resolution of obstructive left-sided colorectal cancer (CRC) as a bridge to elective surgery. However, there is no consensus regarding adequate time intervals from stenting to radical surgery. The aim of this study was to identify the optimal time interval that results in favorable short- and long-term outcomes. METHODS: Data on patients with obstructive left-sided CRC who underwent elective radical surgery after clinically successful SEMS deployment in five tertiary referral hospitals from 2004 to 2016 were analyzed, retrospectively. An inverse probability treatment-weighted propensity score analysis was used to minimize bias. Postoperative short- and long-term outcomes were compared between two groups: an early surgery (within 8 days) group and delayed surgery (after 8 days) group. RESULTS: Of 311 patients, 148 (47.6%) underwent early and 163 (52.4%) underwent delayed surgery. The median surgery interval was 9.0 days. After adjustment, the groups had similar patient and tumor characteristics. In terms of short-term outcomes, there was no difference in hospitalization length or postoperative complications. No deaths were observed. With a median follow-up of 71.0 months, no significant difference was observed between the groups in 5-year overall survival (early vs. delayed surgery: 79.6% vs. 71.3%, P = 0.370) and 5-year disease-free survival (early vs. delayed surgery: 59.1% vs. 60.4%, P = 0.970). CONCLUSIONS: In obstructive left-sided CRC, the time interval between SEMS and radical surgery did not significantly influence short- and long-term outcomes. Therefore, early surgery after SEMS could be suggested if there is no reason to postpone surgery for preoperative medical optimization.

Development and validation of a novel strong prognostic index for colon cancer through a robust combination of laboratory features for systemic inflammation: a prognostic immune nutritional index.

BACKGROUND: Systemic inflammation is associated with survival outcomes in colon cancer. However, it is not well-known which systemic inflammatory marker is a powerful prognostic marker in patients with colon cancer. METHODS: A total of 4535 colon cancer patients were included in this study. We developed a novel prognostic index using a robust combination of seven systemic inflammation-associated blood features of the discovery set. The predictability and generality of the novel prognostic index were evaluated in the discovery, validation and replication sets. RESULTS: Among all combinations, the combination of albumin and monocyte count was the best candidate expression. The final formula of the proposed novel index is named the Prognostic Immune and Nutritional Index (PINI). The concordance index of PINI for overall and progression-free survival was the highest in the discovery, validation and replication sets compared to existing prognostic inflammatory markers. PINI was found to be a significant independent prognostic factor for both overall and progression-free survival. CONCLUSIONS: PINI is a novel prognostic index that has improved discriminatory power in colon cancer patients and appears to be superior to existing prognostic inflammatory markers. PINI can be utilised for decision-making regarding personalised treatment as the complement of the TNM staging system.

Comparison of tumor regression grade and clinical stage based on MRI image as a selection criterion for non-radical management after concurrent chemoradiotherapy in locally advanced rectal cancer: a multicenter, retrospective, cross-sectional study.

PURPOSE: There has been no comparative study on the clinical value of magnetic resonance tumor regression grade (mrTRG)1-2 and ycT0-1N0 for the prediction of ypT0-1N0 after concurrent chemoradiotherapy (CCRT) for rectal cancer. We compared the diagnostic performance between mrTRG1-2 and ycT0-1N0 for predicting ypT0-1N0 as a selection criterion for non-radical management after CCRT in locally advanced rectal cancer. METHODS: This retrospective study enrolled 291 patients from three referral hospitals between January 2018 and March 2020. The diagnostic performance of ycT0-1N0 and mrTRG1-2 for the prediction of ypT0-1N0 was compared in terms of sensitivity, specificity, positive-predictive value, negative-predictive value, and area under the curve (AUC). RESULTS: Sixty-eight patients (23.4%) achieved ypT0-1N0. Nineteen patients (6.5%) had ycT0-1N0, and 91 patients (31.2%) had mrTRG1-2. For predicting ypT0-1N0, ycT0-1N0 had a sensitivity of 16.2% (95% confidence interval [CI]: 8.36‒27.10) and positive-predictive value of 57.9% (95% CI: 36.57‒76.63), while mrTRG1-2 had a sensitivity of 58.8% (95% CI: 46.23‒70.63) and positive-predictive value of 44.0% (95% CI: 36.46‒51.74). When predicting ypT0-1N0, mrTRG1-2 showed a higher AUC (0.680, 95% CI: 0.604‒0.756) than ycT0-1N0 (0.563, 95% CI: 0.481‒0.645) (P < 0.001). CONCLUSION: mrTRG1-2 might be a better indicator than ycT0-1N0 for the selection of non-radical management of advanced rectal cancer post-CCRT. However, additional diagnostic tools are required for predicting ypT0-1N0 because mrTRG1-2 or yc stage on MRI has insufficient evidence for diagnosing ypT0-1N0.

Assessment of the learning curve for the novel transanal minimally invasive surgery simulator model.

BACKGROUND: Transanal minimally invasive surgery (TAMIS) is technically demanding and requires extensive training. We developed the TAMIS simulator model by remodeling an existing laparoscopic training system to educate trainees and analyzed their learning curves. METHODS: Between March 2020 and June 2020, 12 trainees performed TAMIS simulator training sessions. The total operative time, including specimen removal and wound closure, was recorded. The wound closure and specimen quality, trainee self-confidence, and supervisor evaluation of technical performance were documented. A moving average was used to analyze the number of training sessions required to stabilize the procedure time, while a cumulative sum analysis was performed to identify that required to reach proficiency with each item. RESULTS: Each trainee completed 20 TAMIS simulator training sessions. The median total procedure time was 13 min (range, 4-60 min), which stabilized after 15 training sessions. The median times for specimen removal and wound closure were 3 min (range, 1-18 min) and 10 min (range, 2-50 min), respectively, which stabilized after 7 and 15 training sessions, respectively. The mean specimen and wound closure quality scores were 2.9 ± 0.9 (on a scale from 1 to 4) and 2.3 ± 1.1 (on a scale from 1 to 4), respectively, competencies in which were achieved after 16 and 20 training sessions, respectively. The mean trainee self-confidence and supervisor evaluation of technical performance scores were 2.4 ± 1.2 (on a scale from 1 to 5) and 2.7 ± 1.2 (on a scale from 1 to 5), respectively, competencies in which were achieved after 20 and 17 training sessions, respectively. CONCLUSION: Trainees required 15 training sessions to stabilize the procedure time and 16-20 training sessions to demonstrate competencies with the TAMIS simulator model. We expect this simulator model may help surgeons more rapidly acquire the skills required for TAMIS.

Factors associated with diet failure after colon cancer surgery.

BACKGROUND: Since the introduction of Enhanced Recovery After Surgery (ERAS), early diet after surgery has been emphasized and clinical outcomes have improved, though vomiting has been reported frequently. We defined diet failure based on clinical manifestation and images after colon cancer surgery and attempted to analyze underlying risk factors by comparing the early diet group with the conventional diet group. METHODS: All consecutive patients underwent colectomy with curative intent at a single institution between August 2015 and July 2017. The early diet group was started on soft diet on the second day after surgery, while the conventional group started the same after flatulence. The primary outcome was the difference in the incidence of diet failure between the two groups. Secondary outcomes were analyzed to determine risk factors for diet failure and readmission due to ileus. RESULTS: Overall, 293 patients were included in the conventional diet group and 231 in the early diet group. There were no significant differences between the two groups, except for shorter hospital stays in the early diet group (median 8 days, p < 0.001). A total of 46 patients (early diet, n = 20; conventional diet, n = 26, p = 1.000) had diet failure. Multivariate analysis showed that operation time (odds ratio [OR] 1.76, 95% confidence interval [CI] 1.33-2.32) and side-to-side anastomosis compared with the end-to-end method (OR 4.41, 95% CI 2.10-9.24) were independent risk factors for diet failure. Sixteen patients were readmitted due to ileus that occurred within 2 months after surgical operation. Diet resumption time was not a risk factor for both diet failure and ileus. CONCLUSIONS: Early diet resumption does not increase diet failure and can reduce hospital stay. Anastomosis and operation time may be related to diet failure. Our study suggests that evaluation of surgical factors is important for postoperative recovery, and well-designed follow-up studies are needed.

Oncologic safety of laparoscopic surgery after metallic stent insertion for obstructive left-sided colorectal cancer: a multicenter comparative study.

BACKGROUND: Self-expanding metallic stents (SEMSs) are used as a bridge to surgery in patients with obstructive colorectal cancer. However, the role of laparoscopic resection after successful stent deployment is not well established. We aimed to compare the oncologic outcomes of laparoscopic vs open surgery after successful colonic stent deployment in patients with obstructive left-sided colorectal cancer. METHODS: In this multicenter study, 179 (97 laparoscopy, 82 open surgery) patients with obstructive left-sided colorectal cancer who underwent radical resection with curative intent after successful stent deployment were retrospectively reviewed. To minimize bias, we used inverse probability treatment-weighted propensity score analysis. The short- and long-term outcomes between the groups were compared. RESULTS: Both groups had similar demographic and tumor characteristics. The operation time was longer, but the degree of blood loss was lower in the laparoscopy than in the open surgery group. There were nine (9.3%) open conversions. After adjustment, the groups showed similar patient and tumor characteristics. The 5-year disease-free survival (DFS) (laparoscopic vs open: 68.7% vs 48.5%, p = 0.230) and overall survival (OS) (laparoscopic vs open: 79.1% vs 69.0%, p = 0.200) estimates did not differ significantly across a median follow-up duration of 50.5 months. Advanced stage disease (DFS: hazard ratio [HR] 1.825, 95% confidence interval [CI]: 1.072-3.107; OS: HR 2.441, 95% CI 1.216-4.903) and post-operative chemotherapy omission (DFS: HR 2.529, 95% CI 1.481-4.319; OS: HR 2.666, 95% CI 1.370-5.191) were associated with relatively worse long-term outcomes. CONCLUSION: Stent insertion followed by laparoscopy with curative intent is safe and feasible; the addition of post-operative chemotherapy should be considered after successful treatment.

Dual modal spectroscopic tissue scanner for colorectal cancer diagnosis.

BACKGROUND: Margin status is an important prognostic factor for treating colorectal cancer. This study aimed to investigate the usefulness of a multimodal spectroscopic tissue scanner for real-time cancer diagnosis without tissue staining. PATIENTS AND METHODS: Diffuse reflectance spectra (DRS) and fluorescence spectra (FS) of < 1-mm-sized paired cancer and normal mucosa tissue were acquired using custom-built spectroscopic tissue scanners. For FS, we analyzed wavelengths and intensities at peaks and highest intensities near (± 1.25 nm) the known fluorescence spectral peaks of collagen (380 nm), reduced nicotinamide adenine dinucleotide (NADH, 460 nm), and flavin adenine dinucleotide (FAD, 550 nm). For DRS, we performed a similar analysis near the peaks of strong absorbers, oxyhemoglobin (oxyHb; 414 nm, 540 nm, and 576 nm) and deoxyhemoglobin (deoxyHb; 432 nm and 556 nm). Logistic regression analysis for these parameters was performed in the testing set. RESULTS: We acquired 17,735 spectra of cancer tissues and 9438 of normal tissues from 30 patients. Intensity peaks of representative normal spectra for FS and DRS were higher than those of representative cancer spectra. Logistic regression analysis showed wavelength and intensity at peaks, and the intensities of the peak wavelength of NADH, FAD, deoxyHb, and oxyHb had significant coefficients. The area under the receiver operating characteristic curve was 0.927. The scanner had 100%, 64.3%, and 85.3% sensitivity, specificity, and accuracy, respectively. CONCLUSIONS: The spectroscopic tissue scanner has high sensitivity and accuracy and provides real-time intraoperative resection margin assessments and should be further investigated as an alternative to frozen section.

Cross training effects of non-paralytic dorsiflexion muscle strengthening exercise on paralytic dorsiflexor muscle activity, gait ability, and balancing ability in patients with chronic stroke: A randomized, controlled, pilot trial.

OBJECTIVE: To investigate the effects of non-paralytic dorsiflexion muscle strengthening exercise on functional abilities in chronic hemiplegic patients after stroke. METHODS: A total of 21 patients with chronic stroke underwent dorsiflexion muscle strengthening exercise (MST) 5 times a week for 6 weeks (the experimental group, MST to non-paralytic dorsiflexion muscles, n=11; the control group, MST to paralytic dorsiflexion muscles; n=10). Paralytic dorsiflexor muscle activities (DFA) and 10 m walking tests (10MWT) and timed up and go tests (TUG) were measured before and after intervention. RESULTS: A significant increase in DFA was observed after intervention in the experimental and control groups (p<0.05) (experimental 886.6% for reference voluntary contraction (RVC), control 931.6% for RVC). TUG and 10MWT results showed significant reductions post-intervention in the experimental and control groups (experimental group -5.6 sec, control -4.8 sec; experimental group -3.1 sec, control, -3.9 sec; respectively). No significant intergroup difference was observed between changes in DFA or between changes in TUG and 10MWT results after intervention (p>.05). CONCLUSION: Strengthening exercise performed on non-paralytic dorsiflexion muscles had positive cross-training effects on paralytic dorsiflexor muscle activities, balance abilities, and walking abilities in patients with chronic stroke.

Achromatic and athermal design using cost-effective glass selection and aberration-corrected point matching on a glass map.

This paper presents a new method for determining a pair of cost-effective optical materials and powers to achromatize and athermalize a lens system, by introducing the material selection index including price level (MSIP). To obtain a relatively low-cost material effectively, we propose, to the best of our knowledge, a novel glass map including the price levels of the glasses. The materials with a small MSIP were selected on the glass map to correct chromatic aberration and thermal defocus easily, along with providing a cost-effective design. Although there are many material combinations, we can rationally identify the best selection of glasses by checking the MSIP index. Finally, the matching of the aberration-corrected point to an available material by redistributing the optical powers yields a good achromatic and athermal design. Using this aberration-corrected point-matching method, we efficiently obtained an achromatic and athermal system with cost-effective material selection, over the specified temperature and waveband ranges.

Oncological Impact of Lateral Lymph Node Dissection After Preoperative Chemoradiotherapy in Patients with Rectal Cancer.

PURPOSE: To evaluate the efficacy of selective lateral lymph node dissection (LLND) and the effect of preoperative chemoradiotherapy (PCRT) in patients with LLN ≥ 5 mm. METHODS: Patients who underwent PCRT for rectal cancer were classified: (A) total mesorectal excision (TME)-only with LLN < 5 mm (2001-2009, n = 474), (B) TME-only with LLN < 5 mm (2011-2016, n = 273), (C) TME-only with LLN ≥ 5 mm (2001-2009, n = 102), and (D) TME-LLND with LLN ≥ 5 mm (2011-2016, n = 69). Subgroup analysis was performed in patients with LLN ≥ 5 mm based on the reduction in LLN size to < 5 mm or not on restaging MRI after PCRT. RESULTS: Oncological outcomes did not differ between groups A and B. Group D had lower 3-year local recurrence (LR) (20.13% vs 5.39%, P = 0.0013) and higher relapse-free survival (RFS) (65.83% vs 77.11%, P = 0.0436) than group C, while the 3-year overall survival (OS) was not significantly different between the two groups (87.64% vs 93.53%, P = 0.0670). In patients with reduction of LLN size from ≥ 5 mm to < 5 mm, LLND significantly reduced LR than did TME alone, but there were no significant differences in survival outcomes. In patients without reduction of LLN size to < 5 mm, LLND reduced LR and improved RFS compared with TME alone. CONCLUSIONS: Selective LLND reduced LR and improved RFS in patients with LLN ≥ 5 mm. Selective LLND reduced LR in patients with reduction of LLN size from ≥ 5 mm to < 5 mm after PCRT, and improved both LR and RFS in patients without reduction of LLN size to < 5 mm.

Efficacy of health coaching and a web-based program on physical activity, weight, and distress management among cancer survivors: A multi-centered randomised controlled trial.

OBJECTIVES: To investigate the efficacy of health coaching and a web-based program on survivor physical activity (PA), weight, and distress management among stomach, colon, lung and breast cancer patients. METHODS: This randomised, controlled, 1-year trial conducted in five hospitals recruited cancer survivors within 2 months of completing primary cancer treatment who had not met ≥1 of these behavioural goals: (i) conducting moderate PA for at least 150 minutes/week or strenuous exercise for over 75 minutes per week or, in the case of lung cancer patients, low or moderate intensity exercise for over 12.5 MET per week, (ii) maintaining normal weight, and (iii) attaining a score >72 in the Post Traumatic Growth Inventory (PTGI). Participants were randomly assigned to one of three groups: the control group, a web-only group, or a health coaching + web group. The primary endpoint was based on a composite of PA, weight, and PTGI score at 12 months. RESULTS: Patients in the health coaching + web group (difference = 6.6%, P = .010) and the web-only group (difference = 5.9%, P = .031) had greater overall improvements across the three-outcome composite than the control group. The health coaching + web group had greater overall improvement in PTGI (difference = 12.6%; P < .001) than the control group, but not in PA and weight. CONCLUSION: The web-based program, with or without health coaching, may improve health behaviours including PA, weight, and distress management among cancer survivors within 2 months of completing primary cancer treatment. The web-based program with health coaching was mainly effective for reducing psychological distress.

Early Experience With Transanal Total Mesorectal Excision Compared With Laparoscopic Total Mesorectal Excision for Rectal Cancer: A Propensity Score-Matched Analysis.

BACKGROUND: Laparoscopic total mesorectal excision is widely used for rectal cancers; however, it is sometimes challenging, especially in obese patients with low tumors, particularly after chemoradiotherapy. Transanal total mesorectal excision was developed to overcome these limitations in terms of visualization, dissection, and stapling. OBJECTIVE: The purpose of this study was to compare the pathologic and early oncologic outcomes of the laparoscopic and transanal approaches. DESIGN: This was a retrospective comparative study using propensity score-matched analysis. SETTING: The study was conducted at a tertiary hospital specializing in oncology. PATIENTS: In total, 722 inpatients who underwent total mesorectal excision for rectal cancer from January 2014 to December 2017 were included. INTERVENTIONS: Laparoscopic (N = 514) and transanal (N = 208) total mesorectal excision were performed. MAIN OUTCOME MEASURES: The primary outcome was pathologic outcome including circumferential and distal resection margin involvement. The secondary outcomes were intraoperative and postoperative complications and overall survival, recurrence-free survival, and local recurrence rates. RESULTS: The 2 groups of the cohort had several differences; thus, we performed propensity score matching. The circumferential resection margin was involved in 13.4% and 12.9% of the laparoscopic and transanal groups (p = 0.88). The distal resection margin was involved in 1% and 3% of the laparoscopic and transanal groups (p = 0.28). Complete or nearly complete total mesorectal excision was 98.0% and 96.5% in the laparoscopic and transanal groups (p = 0.41). Postoperative complications with Clavien-Dindo grade III or higher did not differ significantly between groups (p = 0.54) but were significantly higher in patients with tumors <5 cm from the anal verge who underwent laparoscopy (laparoscopic group = 11.9%; transanal group = 1.7%; p = 0.04). There were no statistical differences in the 3-year overall survival, recurrence-free survival, or local recurrence rates between groups. LIMITATIONS: This was a retrospective study design with a short follow-up period. CONCLUSIONS: Early experience with the transanal approach showed similar pathologic outcomes as those of conventional laparoscopy; hence, it should be considered as a surgical option for lower rectal cancer. See Video Abstract at http://links.lww.com/DCR/B352. EXPERIENCIA TEMPRANA CON LA ESCISIÓN MESORRECTAL TOTAL TRANSANAL EN COMPARACIÓN CON LA ESCISIÓN MESORRECTAL TOTAL LAPAROSCÓPICA PARA EL CÁNCER DE RECTO: UN ANÁLISIS DE PUNTUACIÓN DE PROPENSIÓN: La escisión mesorrectal total laparoscópica se usa ampliamente para los cánceres rectales; Sin embargo, a veces es un desafío, especialmente en pacientes obesos con tumores bajos, particularmente después de la quimiorradioterapia. La escisión mesorrectal total transanal se desarrolló para superar estas limitaciones en términos de visualización, disección y grapado.Comparar los resultados patológicos y oncológicos precoces de los enfoques laparoscópico y transanal.estudio comparativo retrospectivo con puntaje de propensión-análisis emparejadoHospital terciario especializado en oncología.En total, se incluyeron 722 pacientes hospitalizados que se sometieron a una escisión mesorrectal total por cáncer rectal desde Enero de 2014 hasta Diciembre de 2017.Se realizó escisión mesorrectal total laparoscópica (n = 514) y transanal (n = 208).El resultado primario fue el resultado patológico, incluyendo el involucramiento del margen de resección circunferencial y distal. Los resultados secundarios fueron complicaciones intraoperatorias, postoperatorias y supervivencia general, supervivencia libre de recurrencia y tasas de recurrencia local.Los dos grupos de la cohorte tuvieron varias diferencias; así, realizamos un emparejamiento de puntuación de propensión. El margen de resección circunferencial estuvo involucrado en 13.4% y 12.9% de los grupos laparoscópico y transanal, respectivamente (p = 0.88). El margen de resección distal estuvo involucrado en 1% y 3% de los grupos laparoscópico y transanal, respectivamente (p = 0.28). La escisión mesorrectal total completa o casi completa fue de 98.0% y 96.5% en los grupos laparoscópico y transanal, respectivamente (p = 0.41). Las complicaciones postoperatorias con Clavien-Dindo grado ≥ III no difirieron significativamente entre los grupos (p = 0,54), pero fueron significativamente mayores en pacientes con tumores de < 5 cm del borde anal que se sometieron a laparoscopia (grupo laparoscópico, 11,9%; grupo transanal, 1,7%; p = 0,04). No hubo diferencias estadísticas en la supervivencia general a 3 años, la supervivencia libre de recurrencia y las tasas de recurrencia local entre los grupos.Diseño de estudio retrospectivo, corto período de seguimiento.La experiencia temprana con el enfoque transanal mostró resultados patológicos similares a los de la laparoscopia convencional; por lo tanto, debe considerarse como una opción quirúrgica para el cáncer rectal mas bajo. Consulte Video Resumen en http://links.lww.com/DCR/B352. (Traducción-Dr Yesenia Rojas-Khalil).

Analysis of metachronous colorectal neoplasms and survival following segmental or extended resection in patients with hereditary non-polyposis colorectal cancer.

PURPOSE: The high incidence of metachronous colorectal tumours in patients with hereditary non-polyposis colorectal cancer (HNPCC) encourages extended resection (ER); however, the optimal surgical approach remains unclear. We evaluated the incidences of metachronous colorectal neoplasms following curative colorectal cancer segmental resection (SR) vs ER in patients with HNPCC and investigated patients' oncologic outcomes according to surgical modality and mismatch repair status. METHODS: We retrospectively investigated medical records of patients with HNPCC (per the Amsterdam II criteria) treated for primary colon cancer at our institution between 2001 and 2017. All patients underwent intensive endoscopic surveillance. RESULTS: We included 87 patients (36 who underwent SR and 51 who underwent ER). The cumulative incidence of metachronous adenoma was higher in the SR group. One patient in the SR group (2.8%) and 3 in the ER group (5.9%) developed metachronous colon cancer; the difference was not significant (P = 0.693). Four patients in the SR group (11.1%) and 1 in the ER group (2.0%) developed distant recurrences; again, the difference was not significant (P = 0.155). Moreover, no significant differences were observed in the 5-year overall survival rates of patients in the SR and ER groups (88.2% vs 95.5%, P = 0.446); the same was true for 5-year disease-free survival rates (79.5% vs 91.0%, P = 0.147). CONCLUSION: The incidence of metachronous cancer was not significantly different between the ER and SR groups; however, that of cumulative metachronous adenoma was higher in the SR group. Hence, intensive surveillance colonoscopy may be sufficient for patients with HNPCC after non-extensive colon resection.

Favorable short-term oncologic outcomes following laparoscopic surgery for small T4 colon cancer: a multicenter comparative study.

BACKGROUND: Laparoscopic surgery for T4 colon cancer may be safe in selected patients. We hypothesized that small tumor size might preoperatively predict a good laparoscopic surgery outcome. Herein, we compared the clinicopathologic and oncologic outcomes of laparoscopic and open surgery in small T4 colon cancer. METHODS: In a retrospective multicenter study, we reviewed the data of 449 patients, including 117 patients with tumors ≤ 4.0 cm who underwent surgery for T4 colon cancer between January 2014 and December 2017. We compared the clinicopathologic and 3-year oncologic outcomes between the laparoscopic and open groups. Survival curves were estimated using the Kaplan-Meier method and compared using the log-rank test. Univariate and multivariate analyses were performed using the Cox proportional hazards model. A p < 0.05 was considered statistically significant. RESULTS: Blood loss, length of hospital stay, and postoperative morbidity were lower in the laparoscopic group than in the open group (median [range], 50 [0-700] vs. 100 [0-4000] mL, p < 0.001; 8 vs. 10 days, p < 0.001; and 18.0 vs. 29.5%, p = 0.005, respectively). There were no intergroup differences in 3-year overall survival or disease-free survival (86.6 vs. 83.2%, p = 0.180, and 71.7 vs. 75.1%, p = 0.720, respectively). Among patients with tumor size ≤ 4.0 cm, blood loss was significantly lower in the laparoscopic group than in the open group (median [range], 50 [0-530] vs. 50 [0-1000] mL, p = 0.003). Despite no statistical difference observed in the 3-year overall survival rate (83.3 vs. 78.7%, p = 0.538), the laparoscopic group had a significantly higher 3-year disease-free survival rate (79.2 vs. 53.2%, p = 0.012). CONCLUSIONS: Laparoscopic surgery showed similar outcomes to open surgery in T4 colon cancer patients and may have favorable short-term oncologic outcomes in patients with tumors ≤ 4.0 cm.

Outcomes of high versus low ligation of the inferior mesenteric artery with lymph node dissection for distal sigmoid colon or rectal cancer.

PURPOSE: We compared the complication rates and oncologic and functional outcomes of high versus low ligation of the inferior mesenteric artery (IMA). METHODS: We reviewed data retrospectively from 776 patients, divided into high and low IMA ligation groups. Low ligation was performed with lymph node dissection around the IMA root. Postoperative complications and oncologic and functional outcomes were analyzed. RESULTS: There were 613 patients in the high ligation group and 163 patients in the low ligation group. Most clinicopathological variables were similar. There were no significant differences in complication rates (25.1% vs. 28.8%; p = 0.336), anastomotic leakage (2.8% vs. 2.5%; p = 1.000), colonic ischemia (2.8% vs. 1.2%; p = 0.393), 5-year overall survival (79.6% vs. 81.3%; p = 0.137) or 5-year relapse-free survival (77.4% vs. 73.3%; p = 0.973) between the groups. In terms of functional outcomes, both techniques were equivalent. The International Prostate Symptom Score and Fecal Incontinence Severity Index were significantly better in the low ligation group 12 months postoperatively than 3 months postoperatively. CONCLUSIONS: The oncologic and functional outcomes, as well as postoperative complications, after low ligation of the IMA with lymph node dissection are not significantly different from those after high ligation of the IMA.

Laparoscopic approach for left-sided T4 colon cancer is a safe and feasible procedure, compared to open surgery.

BACKGROUND: A laparoscopic approach can be attempted for pathologic T4 (pT4) colon cancer. Our aim was to evaluate the clinico-oncologic outcomes following laparoscopic versus open surgery for right and left-sided pT4 colon cancer. METHODS: From a multicentric collaborative database, we enrolled 245 patients with right-sided colon cancer (RCC, 128 laparoscopy and 117 open) and 338 with left-sided colon cancer (LCC, 176 laparoscopy and 162 open). All patients underwent intended curative surgery for histologically proven T4 adenocarcinoma, between 2004 and 2013. The primary end-point of our analysis was the oncologic outcome, including the 5-year disease-free survival (5 year-DFS) and the 5-year overall survival (5 year-OS). The secondary end-points included the R0 resection rate and postoperative complications. RESULTS: Our study group included 224 T4N0 and 359 T4N+ tumors. The median follow-up was 53 months. For patients with RCC, the rate of postoperative morbidities was lower for the laparoscopy than that for the open surgery group (12.5 vs. 22.2%, p = 0.044). There was no difference in the R0 resection rate (94.5 vs. 96.6%, p = 0.425) between the groups. The 5 year-DFS and 5 year-OS rates were lower for the laparoscopy than that in the open group (48.9% vs. 59.2%, p = 0.093; 60.0% vs. 70.0%, p = 0.284, respectively), but this difference was not statistically significant. Among patients with LCC, there were no differences in the rate of postoperative complication and R0 resection (15.3 vs. 21.0%, p = 0.307; 96.0 vs. 95.7%, p = 0.875, respectively). Both groups had comparable 5 year-DFS and 5 year-OS rates (62.7% vs. 61.1%, p = 0.552; 72.0% vs. 71.8%, p = 0.611, respectively). CONCLUSIONS: Laparoscopic surgery appears to be a safe procedure for patients with pT4 LCC, but requires careful consideration for patients with pT4 RCC.

Oncologic Risk of Rectal Preservation Against Medical Advice After Chemoradiotherapy for Rectal Cancer: A Multicenter Comparative Cross-Sectional Study with Rectal Preservation as Supported by Surgeon.

BACKGROUND: Rectal preservation against medical advice after neoadjuvant chemoradiotherapy for rectal cancer may increase oncologic uncertainty. This study aimed to compare the oncologic outcomes of patients undergoing rectal preservation as intended by the surgeon, and the outcomes of patients refusing rectal resection against medical advice. METHODS: The study population consisted of patients in whom the rectum was preserved after neoadjuvant chemoradiotherapy for clinical stage I-III mid or low rectal cancer between May 2003 and August 2017 (n = 2883); these patients were divided into those in whom rectal preservation was intended by their surgeon (intended rectal preservation, group A, n = 41) and those in whom the rectum was not resected against medical advice (unintended rectal preservation, group B, n = 101), defined as non-operative management or local excision. RESULTS: The tumor distance, age, and performance status of patients were not significantly different between the groups, while the clinical T stage before chemoradiotherapy was lower in group A than in group B (P < 0.001). During the median follow-up period of 34 months (interquartile range 18.0-72.0 months), the 3-year overall survival in group B (59.7%) was worse than that in group A (90.1%; P < 0.001), and 80.2% of group B patients had residual or unknown disease status. CONCLUSIONS: This study showed that unintended rectal preservation increases oncologic risk after neoadjuvant chemoradiotherapy for rectal cancer regardless of short-term follow-up. Therefore, these findings could be shared with rectal cancer patients who choose to ignore medical advice after chemoradiotherapy to preserve their rectum.

Design of confocal off-axis two-mirror system for head-up display.

We present a new optical system for a combiner-type head-up display (HUD) without any asymmetrical elements by employing a confocal, off-axis, two-hyperboloid mirror as an aberration corrector. From an off-axial aberration analysis, we initially obtain an off-axis two-mirror system corrected for linear astigmatism and spherical aberration by configuring its parameters to satisfy the confocal condition. In addition, to compensate the down angle in the HUD, the image display plane is tilted to satisfy the Scheimpflug condition. This design approach enables us to easily balance the residual aberrations without asymmetrical components, which results in an excellent starting design. The final optical system for an HUD has a virtual image of 7.3 in at 2 m away from an eye box having an area of 130×50 mm2.

Preoperative endoscopic clipping for rectal tumor localization in laparoscopic anterior resection.

Background: Increasing the number of rectal tumors undergoing preoperative chemoradiotherapy or endoscopic resection has increased the importance of accurate tumor localization. This study describes the preoperative endoscopic clipping method for the localization of rectal tumors and evaluated the feasibility of this technique.Material and methods: A total of 109 patients underwent preoperative endoscopic clipping to localize non-palpable rectal adenocarcinomas, which were located within 10 cm from the anal verge. Two endoscopic clips were attached to both lateral sides of the tumor's distal edge. For confirming the distal margin of tumors during surgery, attempts were made to palpate the clips by digital rectal examination.Results: In all 109 cases, endoscopic clips applied to targeted rectal lesions were easily palpable in the operating room. None of the tumors showed involvement at the distal resection margins (median 1.5 cm) in histopathology.Conclusion: Preoperative endoscopic clipping methods can be useful for localizing non-palpable rectal tumors.