Communicative competence of generative artificial intelligence in responding to patient queries about colorectal cancer surgery.

PURPOSE: To examine the ability of generative artificial intelligence (GAI) to answer patients' questions regarding colorectal cancer (CRC). METHODS: Ten clinically relevant questions about CRC were selected from top-rated hospitals' websites and patient surveys and presented to three GAI tools (Chatbot Generative Pre-Trained Transformer [GPT-4], Google Bard, and CLOVA X). Their responses were compared with answers from the CRC information book. Response evaluation was performed by two groups, each consisting of five healthcare professionals (HCP) and patients. Each question was scored on a 1-5 Likert scale based on four evaluation criteria (maximum score, 20 points/question). RESULTS: In an analysis including only HCPs, the information book scored 11.8 ± 1.2, GPT-4 scored 13.5 ± 1.1, Google Bard scored 11.5 ± 0.7, and CLOVA X scored 12.2 ± 1.4 (P = 0.001). The score of GPT-4 was significantly higher than those of the information book (P = 0.020) and Google Bard (P = 0.001). In an analysis including only patients, the information book scored 14.1 ± 1.4, GPT-4 scored 15.2 ± 1.8, Google Bard scored 15.5 ± 1.8, and CLOVA X scored 14.4 ± 1.8, without significant differences (P = 0.234). When both groups of evaluators were included, the information book scored 13.0 ± 0.9, GPT-4 scored 14.4 ± 1.2, Google Bard scored 13.5 ± 1.0, and CLOVA X scored 13.3 ± 1.5 (P = 0.070). CONCLUSION: The three GAIs demonstrated similar or better communicative competence than the information book regarding questions related to CRC surgery in Korean. If high-quality medical information provided by GAI is supervised properly by HCPs and published as an information book, it could be helpful for patients to obtain accurate information and make informed decisions.

Comparison of surgical performance using articulated (ArtiSential®) and conventional instruments for colorectal laparoscopic surgery: A single-centre, open, before-and-after, prospective study.

AIM: Rigid surgical instruments limit movement whereas articulated instruments offer better control in small spaces and allow for intuitive and ergonomic movements. However, the effectiveness of the use of articulated instruments in improving colorectal laparoscopic outcomes remains unclear. The aim of this work was to determine whether colorectal laparoscopic surgical proficiency improved when multijoint instruments were used instead of conventional ones. METHOD: We enrolled 70 consecutive patients (n = 20 for conventional instruments) aged 19-80 years who underwent elective laparoscopic surgery for colorectal diseases. Unedited surgery videos were validated using the modified Global Operative Assessment of Laparoscopic Skills (mGOALS) scale. Learning curves were analysed using a cumulative sum control chart for mGOALS grades. RESULTS: The surgery type, length of hospital stay and 30-day postoperative complication rates were comparable between the groups, and the surgeon's mGOALS grades were similar (p = 0.190). However, in the articulated group, the scores were significantly higher for depth perception (p = 0.012) and tissue-handling domains (p = 0.046), while surgical duration was significantly shorter and intraoperative blood loss was significantly lower (p = 0.022), compared with those in the conventional (p = 0.002) group. Learning curve findings indicated that the first 10 and subsequent 40 surgeries in the articulated group were within the inexperienced and experienced phases, respectively. The mGOALS score in the experienced phase improved in the articulated group compared with that in the conventional group (p = 0.036). CONCLUSIONS: The use of articulated instruments in laparoscopic colorectal surgery showed potential benefits. Further studies are needed to confirm these findings.

Are sporadic colorectal cancers in young patients distinct from those in elderly patients?

AIM: The aim of this study was to compare the clinicopathological and oncological characteristics of sporadic colorectal cancer (CRC) between young and elderly patients without any genetic mutations that cause hereditary CRC. METHOD: In this cross-sectional, retrospective study conducted at three tertiary referral hospitals, we enrolled 1599 patients with CRC who underwent surgery between January 2010 and December 2017, including 157 young patients (age ≤ 40 years; yCRC) and 1442 elderly patients (age ≥ 70 years; eCRC). The clinicopathological and oncological outcomes were compared between the two groups. RESULTS: The median age at diagnosis was 37 years in the yCRC group (range 33.0-39.2 years) and 76 years in the eCRC group (range 72.0-79.0 years). The yCRC group did not present with advanced stages at diagnosis compared with the eCRC group, and the distribution of tumour stages was similar between the two groups. Microsatellite instability (MSI) testing revealed no difference in the frequency of tumours with high MSI (7.8% in yCRC, 5.8% in eCRC), and the frequency of mutations in the KRAS, NRAS and BRAF genes was also similar. The 3-year overall survival was better in the yCRC group than in the eCRC group (97.4% vs. 83.5%, p < 0.001); however, no such difference was observed in cancer-specific survival. CONCLUSION: Genetically proven sporadic CRCs did not differ significantly between young and elderly patients in terms of tumour stage, tumour location and various molecular features. CLINICAL TRIAL REGISTRATION NUMBER: The study was retrospectively registered with Clinical Trials.gov (no. NCT05601609).

Preoperative sequential short-course radiation therapy and FOLFOX chemotherapy versus long-course chemoradiotherapy for locally advanced rectal cancer: a multicenter, randomized controlled trial (SOLAR trial).

BACKGROUND: Preoperative (chemo)radiotherapy has been widely used as an effective treatment for locally advanced rectal cancer (LARC), leading to a significant reduction in pelvic recurrence rates. Because early administration of intensive chemotherapy for LARC has more advantages than adjuvant chemotherapy, total neoadjuvant therapy (TNT) has been introduced and evaluated to determine whether it can improve tumor response or treatment outcomes. This study aims to investigate whether short-course radiotherapy (SCRT) followed by intensive chemotherapy improves oncologic outcomes compared with traditional preoperative long-course chemoradiotherapy (CRT). METHODS: A multicenter randomized phase II trial involving 364 patients with LARC (cT3-4, cN+, or presence of extramural vascular invasion) will be conducted. Patients will be randomly assigned to the experimental or control arm at a ratio of 1:1. Participants in the experimental arm will receive SCRT (25 Gy in 5 fractions, daily) followed by four cycles of FOLFOX (oxaliplatin, 5-fluorouracil, and folinic acid) as a neoadjuvant treatment, and those in the control arm will receive conventional radiotherapy (45-50.4 Gy in 25-28 fractions, 5 times a week) concurrently with capecitabine or 5-fluorouracil. As a mandatory surgical procedure, total mesorectal excision will be performed 2-5 weeks from the last cycle of chemotherapy in the experimental arm and 6-8 weeks after the last day of radiotherapy in the control arm. The primary endpoint is 3-year disease-free survival, and the secondary endpoints are tumor response, overall survival, toxicities, quality of life, and cost-effectiveness. DISCUSSION: This is the first Korean randomized controlled study comparing SCRT-based TNT with traditional preoperative LC-CRT for LARC. The involvement of experienced colorectal surgeons ensures high-quality surgical resection. SCRT followed by FOLFOX chemotherapy is expected to improve disease-free survival compared with CRT, with potential advantages in tumor response, quality of life, and cost-effectiveness. TRIAL REGISTRATION: This trial is registered at Clinical Research Information under the identifier Service KCT0004874 on April 02, 2020, and at Clinicaltrial.gov under the identifier NCT05673772 on January 06, 2023.

Clinical impact of preoperative and postoperative sarcopenia on oncological outcomes in non-metastatic colorectal cancer.

AIM: This study investigated the association between preoperative and postoperative changes in skeletal muscle mass and long-term oncological outcomes in patients with non-metastatic colorectal cancer. METHOD: Patients who underwent surgery for Stages I-III colorectal cancer from January 2014 to December 2015 were included. Skeletal muscle mass was evaluated through preoperative and postoperative abdominopelvic CT scans. A multivariable analysis was conducted to determine the factors affecting disease-free survival rates. RESULTS: A total of 238 patients were analysed. Forty-nine (25.9%) patients had preoperative sarcopenia. Patients with preoperative sarcopenia showed lower 3-year disease-free survival (58.5% vs. 78.4%, P = 0.001). Patients with postoperative sarcopenia also showed significantly lower 3-year disease-free survival compared to postoperative patients without sarcopenia at 6, 12 and 18 months, respectively (53.9% vs. 77.8%; 69.7% vs. 81.8%; 69.1% vs. 87.7%, P = 0.004). In a subgroup analysis, patients with both preoperative and postoperative sarcopenia showed the lowest 3-year disease-free survival rates (50.9%). The incidence of tumour recurrence was higher among the patients who had lost more skeletal muscle mass at 12, 18 and 24 months (-14.3 cm2 /m2 vs. -1.5 cm2 /m2 , P < 0.001; -24.5 cm2 /m2 vs. -1.1 cm2 /m2 , P < 0.001; and -31.6 cm2 /m2 vs. -1.4 cm2 /m2 , P < 0.001, respectively). A multivariable analysis demonstrated that the factors associated with disease-free survival included tumour stage, venous invasion, adjuvant chemotherapy, and preoperative or postoperative sarcopenia. CONCLUSION: Not only preoperative but also postoperative sarcopenic changes adversely affect oncological outcomes following curative resection of colorectal cancer. Careful attention should be given to correcting sarcopenic status from the preoperative to the postoperative period.

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.

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.

Objective recovery time with end-to-side versus side-to-side anastomosis after laparoscopic right hemicolectomy for colon cancer: a randomized controlled trial.

BACKGROUND: Despite reports of the short-term benefits of end-to-side versus side-to-side anastomosis, we are aware of no prospective studies in which these methods were compared. We hypothesized the superiority of end-to-side over side-to-side anastomosis in terms of recovery after laparoscopic right hemicolectomy for colon cancer under an enhanced recovery program. METHODS: From September 2016 to August 2019, 130 patients were randomly allocated to receive end-to-side or side-to-side anastomosis at a single tertiary hospital in Korea. The primary outcome was the cumulative recovery rate seven days after surgery, defined as the percentage of patients who met all four recovery criteria: diet tolerance, no analgesia, safe ambulation, and an afebrile status. Student's t test, the Mann-Whitney U test, the χ2 test, and Fisher's exact test were used to compare variables, as applicable. RESULTS: The cumulative recovery rate at seven days did not differ between patients receiving end-to-side (92.3%, 60/65) or side-to-side anastomosis (92.3%, 60/65; P ≥ 0.999). The end-to-side and side-to-side groups had similar cumulative recovery rates at postoperative days 4, 5, and 6 (end-to-side vs. side-to-side: 41.5% vs 35.4%, P = 0.589; 73.8% vs 63.1%, P = 0.257; and 86.2% vs 81.5%, P = 0.634, respectively). None of the secondary endpoints differed for end-to-side vs. side-to-side anastomosis: the median length of postoperative hospitalization (5 [IQR 5-7] vs. 6 [IQR 5-7] days, respectively, P = 0.376), the 30-day complication rate (16.9% vs. 12.3%, respectively, P = 0.620), the enhanced recovery protocol failure rate (10.8% vs. 7.7%, respectively, P = 0.763), and the 30-day readmission rate (4.6% vs. 3.1%, respectively, P ≥ 0.999). CONCLUSIONS: End-to-side anastomosis was not superior to side-to-side anastomosis in terms of recovery criteria after laparoscopic right hemicolectomy. These findings do not provide evidence for a functional advantage of end-to-side compared to side-to-side anastomosis.

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.

Expression of human leukocyte antigen class I and ß2-microglobulin in colorectal cancer and its prognostic impact.

Downregulation of human leukocyte antigen (HLA) class I has been postulated to be a mechanism of adaptive immune escape in various tumors, especially microsatellite instability-high (MSI-H) colorectal cancer (CRC). In this study, we aimed to investigate HLA class I and ß2-microglobulin (ß2M) expression in MSI-H and microsatellite-stable (MSS) CRCs and determine its prognostic impact. The representative areas from the tumor center (TC) and tumor periphery (TP) from 300 CRCs, including 161 MSI-H and 139 MSS cases, were selected to construct a tissue microarray. Immunohistochemistry (IHC) for HLA A/B/C, ß2M, CD3, and CD8 was performed. Reduced HLA A/B/C expression was detected in 113 (70.2%) MSI-H and 54 (38.8%) MSS cases, while reduced ß2M expression was observed in 69 (42.9%) MSI-H and 17 (12.2%) MSS cases. Although reduced ß2M expression was associated with higher pathological tumor (pT) stage in MSI-H CRC with borderline significance, no association was found between HLA A/B/C and ß2M expression and survival. Interestingly, reduced HLA A/B/C expression in MSS was associated with higher stage, and reduced HLA A/B/C and ß2M expression was an independent prognostic factor in multivariate analysis. In conclusion, reduced HLA A/B/C and ß2M expression was frequently observed in immunotherapy-naive MSI-H CRC, suggesting the possibility of primary resistance to immune checkpoint inhibitor. Interestingly, downregulation of HLA A/B/C and ß2M was associated with poor prognosis in MSS cancers. Overall, IHC for HLA A/B/C and ß2M might be a feasible predictive or prognostic tool in CRC.

Effects of probiotics on bowel function restoration following ileostomy closure in rectal cancer patients: a randomized controlled trial.

AIM: The aim was to determine the efficacy of probiotics in restoring bowel function following ileostomy reversal in patients with rectal cancer. METHOD: This was a pilot, randomized, double-blind, placebo-controlled trial. The probiotic used in this study, Lactobacillus plantarum CJLP243, was derived from kimchi. Patients were randomly allocated to a probiotic or placebo group and medication was taken once daily from preoperative day 1 to day 21. Primary outcomes were the Memorial Sloan Kettering Cancer Centre Bowel Function Index (MSKCC BFI) instrument and the low anterior resection syndrome score. The secondary outcomes were the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30 and CR29 questionnaire responses. RESULTS: Forty patients were enrolled, and 36 patients (probiotics, n = 17; placebo, n = 19) completed the primary outcomes. Total scores for the MSKCC questionnaire (56.2 ± 12.0 vs. 55.0 ± 10.7, P = 0.356) and low anterior resection syndrome scores (33.3 ± 7.6 vs. 36.0 ± 5.3, P = 0.257) were not significantly different between the probiotic and placebo groups, respectively. In the MSKCC BFI, the postoperative dietary scale score at week 1 was significantly higher in the probiotic group (13.1 ± 3.8 vs. 9.0 ± 3.0, P < 0.001). There were no other significant differences between the two groups for any other questionnaire scores. CONCLUSION: There were no significant effects supporting the use of a probiotic for improved bowel function in patients following ileostomy reversal. Nevertheless, the administration of probiotics showed trends toward improvements in some subscale bowel function measures, suggesting further studies may be warranted.

Extent of Pedigree Required to Screen for and Diagnose Hereditary Nonpolyposis Colorectal Cancer: Comparison of Simplified and Extended Pedigrees.

BACKGROUND: Obtaining an accurate pedigree is the first step in recognizing a patient with hereditary nonpolyposis colorectal cancer, or Lynch syndrome. However, lack of standardization of the degree of relationship included in the pedigrees generally limits obtaining a complete and/or accurate pedigree. DESIGN: This study analyzed the extent of pedigree required to screen for colorectal cancer and to diagnose Lynch syndrome. SETTINGS: The study was conducted at 2 tertiary care centers. PATIENTS: A detailed family history was obtained from patients undergoing surgery for colorectal cancer from 2003 to 2016. A simplified pedigree that included only first-degree relatives was obtained and compared with the extended pedigree. MAIN OUTCOME MEASURES: The eligibility of the 2 pedigrees was assessed for each proband. The proportion of patients who would be missed using a simplified rather than an extended pedigree was calculated based on the American Cancer Society guidelines for recommending screening for colorectal cancer, on the revised Bethesda guidelines and the revised suspected hereditary nonpolyposis colorectal cancer criteria for screening for hereditary colorectal cancer, and on the Amsterdam II criteria for diagnosis of Lynch syndrome. RESULTS: The study examined 2015 families, including 41,826 individuals. Use of simplified and extended pedigrees was comparable in screening for colorectal cancer, with ratios of 183 of 185 (98.9%) for American Cancer Society guidelines, 295 of 295 (100%) for revised Bethesda guidelines, and 60 of 60 (100%) for revised suspected hereditary nonpolyposis colorectal cancer criteria. However, the use of simplified pedigrees missed a definitive diagnosis of Lynch syndrome in 6 of 10 patients fulfilling Amsterdam II criteria based on extended pedigrees. The mean ages at diagnosis of the 4 probands included and the 6 missed using simplified pedigrees differed significantly (60.8 vs 38.2 y). LIMITATIONS: The study was limited by its recall bias, cross-sectional nature, lack of germline testing, and potential inapplicability to the general population. CONCLUSIONS: A simplified pedigree is acceptable for selecting candidates to screen for hereditary colorectal cancer, whereas an extended pedigree is still required for a more precise diagnosis of Lynch syndrome, especially in younger patients. See Video Abstract at http://links.lww.com/DCR/B97. EXTENSIÓN DE PEDIGREE REQUERIDO EN LA DETECCIÓN Y DIAGNÓSTICO DE CÁNCER COLORRECTAL HEREDITARIO SIN POLIPOSIS: COMPARACIÓN DE LOS PEDIGREES SIMPLIFICADO Y EL EXTENDIDO: La obtención de un Pedigree exacto es el primer paso para reconocer un paciente con cáncer colorrectal hereditario sin poliposis o síndrome de Lynch. Sin embargo, la falta de estandarización del grado de relación incluido en los Pedigrees generalmente limita la obtención de un Pedigree completo y / o preciso.Este estudio analizó el grado de Pedigree requerido para detectar el cáncer colorrectal y diagnosticar el síndrome de Lynch.Se obtuvo una historia familiar detallada de pacientes sometidos a cirugía por cáncer colorrectal desde 2003 hasta 2016. Se obtuvo también un Pedigree simplificado que incluía solo familiares de primer grado y se comparó con el Pedigree extendido.La elegibilidad de los dos Pedigrees se evaluó para cada sujeto de prueba (proband). La proporción de pacientes que se perderían usando un Pedigree simplificado en lugar de extendido se calculó en base a las guías de la Sociedad Americana del Cáncer y sus recomendaciones en la detección de cáncer colorrectal, en las pautas revisadas de Bethesda y en los criterios revisados de cáncer colorrectal hereditario sin poliposis para la detección hereditaria de cáncer colorrectal y según las normas de Amsterdam II para el diagnóstico del síndrome de Lynch.El estudio examinó a 2.015 familias, incluidas 41.826 personas. El uso de Pedigree simplificado y extendido fue comparable en la detección del cáncer colorrectal, con proporciones de 183/185 (98,9%) comparadas con las recomendaciones de la American Cancer Society, 295/295 (100%) para las pautas revisadas de Bethesda y 60/60 (100%) para los criterios revisados de sospecha de cáncer colorrectal hereditario sin poliposis. Sin embargo, el uso de Pedigree simplificado omitió un diagnóstico definitivo del síndrome de Lynch en 6 de diez pacientes que cumplían las normas de Amsterdam II basados en Pedigrees extendidos. Las edades medias al diagnóstico de los cuatro sujetos de prueba incluidos y los seis perdidos usando el Pedigree simplificado diferían significativamente (60.8 vs. 38.2 años).Un Pedigre simplificado es aceptable en la selección de candidatos para la detección de cáncer colorrectal hereditario, mientras que aún se requiere un Pedigree extendido para un diagnóstico más preciso de síndrome de Lynch, especialmente en pacientes más jóvenes. Consulte Video Resumen en http://links.lww.com/DCR/B97. (Traducción-Dr. Edgar Xavier Delgadillo).

Is elevated microsatellite alterations at selected tetranucleotide repeats (EMAST)-negative/MSI-high colorectal cancer a distinct subtype of the disease?

BACKGROUND AND OBJECTIVES: Microsatellite instability (MSI) plays a prognostic and predictive role in colorectal cancer (CRC). Elevated microsatellite alterations at selected tetranucleotide repeats (EMAST), a novel type of MSI, was recently identified. METHODS: A retrospective analysis of a prospective cohort database was performed. Patients who attempted curative surgery for MSI-high (MSI-H) CRC and had available testing results of EMAST were included for analysis. The difference in clinical characteristics, immunohistochemistry profile, and 3-year recurrence-free and overall survival between EMAST-negative and EMAST-positive tumors was measured. RESULTS: EMAST status was successfully evaluated in 86 cases among patients who received EMAST testing, and only 16.3% (14/86) of these patients were EMAST-negative/MSI-H. Patients with EMAST-negative tumors were younger; their tumors exhibited well differentiation, less venous invasion, and greater mutS homolog 3 expression. There was no distant metastasis or cancer-specific death among EMAST-negative patients. Yet no statistically significant difference was found between the two groups in 3-year overall or recurrence-free survival. CONCLUSIONS: Patients with EMAST-negative/MSI-H CRC seem to have different clinicopathological characteristics. Future large-scale studies could clarify the role of EMAST genotype as a sub-classifier of MSI-H CRC.

Surgical outcomes according to the type of monopolar electrocautery device used in laparoscopic surgery for right colon cancer: a comparison of endo-hook versus endo-shears.

BACKGROUND: Although monopolar electrocautery is preferred by many laparoscopic surgeons and is more cost-effective than bipolar or ultrasonic scissors, few studies have compared these outcomes between different monopolar electrocautery devices used in laparoscopic surgery. Therefore, this study compared the surgical outcomes between monopolar endo-hook versus endo-shears during laparoscopic right hemicolectomy for right colon cancer. METHODS: Using a prospective database of patients treated at our institute, we analyzed the surgical outcomes of 358 consecutive patients with right colon cancer who underwent curative laparoscopic surgery with a monopolar endo-hook (n = 164) or endo-shears (n = 194) between March 2009 and March 2017. RESULTS: There were no differences in age, sex, body mass index, American Society of Anesthesiologists' grade, previous operative history, or clinical stage between the endo-hook and endo-shears groups. The estimated blood loss was similar between the endo-hook and endo-shears groups (90.9 ± 60.3 vs. 92.0 ± 89.3 mL; P = 0.893). The number of harvested lymph nodes was greater in the endo-hook group (53.5 ± 20.3 vs. 48.1 ± 18.5; P = 0.008). Hospital stay was shorter in the endo-hook group (6.8 ± 2.2 vs. 7.8 ± 4.8 days; P = 0.013). Although chylous ascites was more frequent in the endo-hook group (21.3% vs. 7.7%, P < 0.001), the postoperative morbidity rate was lower in this group (9.8% vs. 18.0%; P = 0.025). All instances of chylous ascites healed spontaneously without intervention. CONCLUSIONS: This study showed that the use of a monopolar endo-hook during laparoscopic right hemicolectomy might permit more meticulous lymph-node dissection and reduce morbidity compared with the use of monopolar endo-shears. Therefore, we suggest that the outcomes of laparoscopic surgery might be associated with the type of electrocautery device used.

Impact of Family History on Prognosis of Patients with Sporadic Colorectal Cancer.

PURPOSE: A family history (FH) of colorectal cancer (CRC) increases the risk for development of CRC, but the impact of FH of CRC on survival from sporadic CRC is unclear. This study investigated the prognostic impact of FH of CRC on the recurrence and survival of patients with sporadic CRC. METHODS: We reviewed the records of patients with sporadic CRC from two tertiary referral hospitals in Korea who underwent surgical resection between May 2007 and September 2013. The clinicopathologic features and oncologic outcomes of those with and without FHs of CRC were compared. RESULTS: We examined the records of 2960 eligible patients, 163 (5.5%) of whom had first-degree relatives with CRC. Patients with and without FHs of CRC had similar baseline characteristics. Multivariable analysis indicated that a FH of CRC was not significantly associated with disease-free survival but was significantly associated with better overall survival (OS) [adjusted hazard ratio = 0.539, 95% confidence interval (CI) 0.330-0.881, P = 0.014]. Subgroup analysis indicated that females and rectal cancer patients with FHs of CRC had significantly better prognoses. Microsatellite status did not affect the improved survival rate associated with FH. CONCLUSIONS: This study of patients with sporadic CRC indicated that those who had FHs of CRC had better OS but similar cancer recurrence as those who had no FH of CRC. The effect of FH of CRC on OS was independent of microsatellite status. Further studies are needed to identify underlying mechanisms and determine the optimal clinical management of CRC according to FH.

Resting vector volume measured before ileostomy reversal may be a predictor of major fecal incontinence in patients with mid or low rectal cancer: a longitudinal cohort study using a prospective clinical database.

PURPOSE: Despite a high incidence of fecal incontinence following sphincter-preservation surgery (SPS), there are no definitive factors measured before ileostomy reversal that predict fecal incontinence. We investigated whether vector volume anorectal manometry before ileostomy reversal predicts major fecal incontinence following SPS in patients with mid or low rectal cancer. METHODS: This longitudinal prospective cohort study comprised 173 patients who underwent vector volume anorectal manometry before ileostomy reversal. The Fecal Incontinence Severity Index was measured 1 year after the primary SPS and classified as major incontinence (FISI score ≥ 25) or continent/minor incontinence (FISI score < 25). Multivariable logistic regression analysis was used to identify predictors of major incontinence. RESULTS: Ninety-two patients (53.1%) had major incontinence. Although tumor stage, location, and neoadjuvant chemoradiotherapy were comparable, the major incontinence group had lower resting pressure (28.4 vs. 34.3 mmHg, P = 0.027), greater asymmetry at rest (39.1% vs. 34.1%, P = 0.002) and squeezing (34.2% vs. 31.4%, P = 0.046), shorter sphincter length (3.3 vs. 3.7 cm, P = 0.034), and lower resting vector volume (143,601 vs. 278,922 mmHg2 mm, P < 0.001) compared with the continent/minor incontinence group. Resting vector volume was the only independent predictor of major incontinence (odds ratio = 0.675 per 100,000 mmHg2 mm, 95% confidence interval, 0.532-0.823; P = 0.006). CONCLUSIONS: This study revealed that resting vector volume before ileostomy reversal may predict major fecal incontinence. We suggest that the physiology of the anorectum should be discussed with patients before ileostomy reversal in patients at high risk of fecal incontinence.