The impact of lymph node size to predict nodal metastasis in patients with rectal cancer after preoperative chemoradiotherapy.

PURPOSE: During restaging after preoperative chemoradiotherapy (CRT), the assessment of lymph node (LN) metastasis is vital for selecting further treatment strategies. This study aimed to evaluate the impact of LN size to predict LN metastasis in rectal cancer patients after preoperative CRT. METHODS: A total of 30 consecutive patients who underwent preoperative CRT followed by curative resection of primary rectal cancer were selected as a study group (CRT group). As a control group (non-CRT group), 30 patients who underwent primary tumor resection were selected using a 1:1 case-match design. Matching criteria were gender, age, and clinical T stage. The size of each LN was measured from the surgical specimen. To clarify optimal cutoff values for node size according to the risk of detecting metastasis, receiving-operator characteristic (ROC) curves were generated. RESULTS: In the non-CRT group, 39/474 LNs were confirmed to have metastasis. In the CRT group, 29/422 LNs showed metastasis. The median size of metastatic LNs was 6.0 mm in CRT group, which was significantly larger than 4.0 mm in the non-CRT group (p = 0.006). The optimal cutoff value for determining metastasis in the CRT group was 4.5 mm, compared to 3.5 mm in the non-CRT group. The accuracy of the cutoff value was much higher in the CRT group (CRT vs. non-CRT, 77.9 vs. 59.9%). CONCLUSIONS: LN size is a strong indicator for prediction of regional LN metastasis in rectal cancer patients after preoperative CRT, compared to those without CRT.

Effect of preoperative colonoscopic tattooing on lymph node harvest in T1 colorectal cancer.

OBJECTIVE: This study aimed to identify the impact of preoperative colonoscopic tattooing (PCT) on lymph node harvest in T1 colorectal cancer patients. MATERIAL AND METHODS: One hundred and forty-three patients were included who underwent curative resection and were diagnosed with T1 colorectal cancer. These patients were categorized into the tattooing group and the non-tattooing group depending on whether preoperative India ink tattooing was done. Clinicopathological findings and lymph node harvest were compared between the two groups. RESULTS: The median number of lymph nodes examined was 18 in the tattooing group and 13 in the non-tattooing group (p < 0.001). The rate of adequate lymph node harvest (retrieval of more than 12 lymph nodes) was higher in the tattooing group than that in the non-tattooing group (83.7 vs. 58.5 %, p = 0.002). The PCT was significantly associated with adequate lymph node harvest in multivariate analysis (hazard ratio, 3.8; 95 % confidence interval, 1.5-9.2; p = 0.003). Among the 40 patients who showed at least one carbon particle-containing lymph nodes, the positive lymph node rate was not different between carbon-containing LNs (0.9 %) and non-carbon-containing LNs (1.7 %). CONCLUSIONS: PCT was associated with higher lymph node yield in T1 colorectal cancer. It is questionable if tattooing has additional detection power as a sentinel lymph node mapping tool in T1 colorectal cancer.

A high-throughput assay of NK cell activity in whole blood and its clinical application.

Natural killer (NK) cells are lymphocytes of the innate immune system and have the ability to kill tumor cells and virus-infected cells without prior sensitization. Malignant tumors and viruses have developed, however, strategies to suppress NK cells to escape from their responses. Thus, the evaluation of NK cell activity (NKA) could be invaluable to estimate the status and the outcome of cancers, viral infections, and immune-mediated diseases. Established methods that measure NKA, such as (51)Cr release assay and CD107a degranulation assay, may be used to determine NK cell function, but they are complicated and time-consuming because they require isolation of peripheral blood mononuclear cells (PBMC) or NK cells. In some cases these assays require hazardous material such as radioactive isotopes. To overcome these difficulties, we developed a simple assay that uses whole blood instead of PBMC or isolated NK cells. This novel assay is suitable for high-throughput screening and the monitoring of diseases, because it employs serum of ex vivo stimulated whole blood to detect interferon (IFN)-γ secreted from NK cells as an indicator of NKA. After the stimulation of NK cells, the determination of IFNγ concentration in serum samples by enzyme-linked immunosorbent assay (ELISA) provided a swift, uncomplicated, and high-throughput assay of NKA ex vivo. The NKA results microsatellite stable (MSS) colorectal cancer patients was showed significantly lower NKA, 263.6 ± 54.5 pg/mL compared with healthy subjects, 867.5 ± 50.2 pg/mL (p value <0.0001). Therefore, the NKA could be utilized as a supportive diagnostic marker for microsatellite stable (MSS) colorectal cancer.

Is prior laparoscopy experience required for adaptation to robotic rectal surgery?: Feasibility of one-step transition from open to robotic surgery.

PURPOSE: The objective of this study is to ascertain the impact of laparoscopic colorectal surgery (LCS) experience on the learning curve of robotic rectal cancer surgery (RRS). Whether LCS experience is mandatory on overcoming the learning curve of RRS or not remains undetermined. METHODS: Before starting the robotic procedure, surgeon A had a limited experience of less than 30 LCS cases, whereas surgeon B had performed more than 300 cases of LCS. From the beginning, 100 consecutive, unselected RRS cases performed by each of the two surgeons were retrospectively analyzed (groups A and B). Perioperative surgical and oncologic outcomes were compared between the two groups. RESULTS: Clinicopathological characteristics between the two groups were similar. One case in group A was converted to open surgery. Mean operation time was shorter in group A than that of group B (272 vs. 344 min, p < 0.001). Overall perioperative morbidity rates were not different between the two groups (17.0 vs. 10.0 %, p = 0.214). There was no difference of circumferential resection margin positivity rate and retrieved lymph node numbers. In group A, the operation time decreased with a steep slope until 17 cases on the moving average curve. The slope in group B maintained a steady state and showed no remarkable changes throughout the study period. CONCLUSIONS: A one-step transition from open to robotic rectal cancer surgery can be achieved without having extensive prior laparoscopic experience.

Laparoscopic right hemicolectomy with complete mesocolic excision.

BACKGROUND: Complete mesocolic excision (CME) has recently been reemphasized as a technical approach for anatomical dissection during colon cancer surgery. Although a laparoscopic approach for right colon cancer is performed frequently, identifying an adequate dissection plane is not always easy. In our practice, the patient lies in a modified lithotomy position. The first step is ileocolic area mobilization, followed by adequate retraction of the cecum laterally. This procedure enables discrimination of the ileocolic vessels and superior mesenteric vessels. Importantly, this method facilitates identification of the superior mesenteric vein (SMV), followed by the identification of the root of ileocolic pedicles. After that, sharp dissection along the SMV in an upward direction helps to safely identify the middle colic artery (MCA). Dissection then continues to the level of the origin of MCA, after which the right branch of MCA can be divided. METHODS: A total of 128 consecutive patients (63 males) who underwent laparoscopic CME for right colon cancer by a single surgeon were analyzed in this study. RESULTS: There was no conversion to open surgery. The median operation time was 192 min (interquartile range [IQR] 118-363 min). The median proximal and distal resection margins were 11 and 10 cm, respectively. The median number of harvested lymph nodes was 28 (IQR 3-88). There were six postoperative complications (4.6 %). The median hospital stay was 5 days (IQR 4-37 days). The video demonstrates a laparoscopic CME for a patient who had advanced distal ascending colon cancer. CONCLUSION: In conclusion, identifying the anatomical location of the SMV and performing meticulous dissection along the SMV is an essential procedure for containing all potential routes of metastatic tumors. Initial ileocecal mobilization with adequate counter traction of the cecum may be useful for novice surgeons attempting to identify the location of SMV during laparoscopic CME for right colon cancer.

Evaluating the effect of age on postoperative and clinical outcomes in patients admitted to the intensive care unit after gastrointestinal cancer surgery.

BACKGROUND: This study aimed to compare postoperative and clinical outcomes according to age and analyze the effect of age on mortality in patients admitted to the intensive care unit immediately after gastrointestinal cancer surgery. METHODS: A total of 477 patients admitted to the intensive care unit after gastrointestinal cancer surgery between March 2018, and February 2020, were classified into 3 groups according to age: young (<65 years), older (65-79 years), and oldest (≥80 years) groups. We compared their disease severity scores as well as postoperative and clinical outcomes including mortality. RESULTS: The young group comprised 167 (35.0%) patients, the older group 222 (46.5%) patients, and the oldest group 88 (18.4%) patients. There was a significant difference in the American Society of Anesthesiologists score, but not in the Acute Physiology and Chronic Health Evaluation II score, among the groups. The younger the age, the higher was the rate of vasopressor use; however, there were no significant differences in other postoperative and clinical outcomes, such as mechanical ventilation, length of hospital stay, length of intensive care unit stay, form of discharge, intensive care unit re-admission rate, in-hospital mortality, and in-30 days mortality. No significant differences in in-hospital survival, in-30 days survival, and overall survival were observed among the 3 groups. CONCLUSION: The comorbidities of patients increase with age; however, there was no significant difference in postoperative and clinical outcomes related to age. Thereby, the older population can successfully undergo major operations if adequate perioperative management is provided.

Clinical application of protein-enhanced diet using mealworms in patients undergoing hepato-pancreato-biliary surgery.

OBJECTIVE: Patients with or without cancers who undergo major gastrointestinal surgery experience malnutrition owing to their catabolic status during the postoperative period. In this study, we evaluated the effect of the clinical application of protein-enhanced diet using mealworms in patients who underwent hepato-pancreato-biliary surgeries. METHODS: This study was designed as a prospective, two-armed, and double-blinded phase III study. The target number of enrolled patients was 216, and the patients were randomized on a 1:1 basis, either to the trial group (consuming mealworms) or to the control group (consuming grain powder). The primary endpoint was to examine the changes in body composition, including phase angle. For secondary outcomes, the activities of immune cells were evaluated using the patients' blood samples. RESULTS: No difference in the demographic characteristics of patients was observed. The ratio of the actual protein intake to the recommended daily intake in the trial group was significantly higher than that in the control group (110.03% vs. 98.80%, P = 0.023). In the data on body composition measured by InBody S-10 (Biospace, Seoul, South Korea), the ratios in body cell mass, fat free mass, muscle mass, and phase angle at the study endpoint compared with those at admission showed no statistically significant difference between the two groups. Immune cell analyses suggested that cytotoxic T cells in the trial group had higher activity than in the study group (1.192 vs. 0.974, P = 0.028). CONCLUSIONS: In this study, protein-enhanced diet using mealworms clinically improved the activity of immune cells. However, it did not significantly improve the patients' nutritional status after they experienced hepato-pancreato-biliary surgeries.

The effect of preoperative portal vein embolization on liver regeneration after extended hepatic resection.

BACKGROUND/AIMS: This study was designed to evaluate the effect of portal vein embolization on liver regeneration after major liver resection. METHODOLOGY: A retrospective analysis was performed on 24 patients who underwent extended hepatectomy for hilar cholangicellular carcinoma between 2001 and 2008. Eleven patients underwent portal vein embolization and 13 did not. Computed tomography volumetry was used to assess liver volume. RESULTS: Clinical and operative characteristics were comparable between portal vein embolization group and non-portal vein embolization group, except for mean estimated blood loss (p=0.034). Future remnant liver volume (p=0.004) differed between groups. However, preoperative future remnant liver volume (p=0.331), postoperative mean volume of the left lateral segement (p>0.9), total volume increase (p>0.9), and daily volume increase (p>0.9) did not differ significantly between groups. Within the portal vein embolization group, mean volume of the left lateral segment and daily volume increase after hepatic resection were significantly greater than after portal vein embolization (p=0.002). CONCLUSION: Liver regeneration after portal vein embolization was insignificant in comparison with that after extended hepatectomy. Moreover, portal vein embolization performed before extended hepatectomy did not reinforce liver regeneration after major liver resection.

Immune-modulating Effect of Korean Red Ginseng by Balancing the Ratio of Peripheral T Lymphocytes in Bile Duct or Pancreatic Cancer Patients With Adjuvant Chemotherapy.

BACKGROUND/AIM: We aimed to clarify the clinical effect of Korean Red ginseng administered with adjuvant chemotherapy on the immune function of patients with bile duct or pancreatic cancer. PATIENTS AND METHODS: This was a prospective, randomized controlled trial conducted at a single tertiary center. Twenty-six consecutive patients who underwent curative resection for bile duct or pancreatic cancer followed by 5-fluorouracil/leucovorin or gemcitabine chemotherapy were included. They were randomized 1:1 to the ginseng and control groups. Immune and inflammatory markers were assayed in peripheral blood samples during and after chemotherapy. RESULTS: Intergroup differences in immune-related parameters before and during chemotherapy were not significant. After chemotherapy, the percentage of CD4+ T lymphocytes was significantly higher in the ginseng group than in the control group (42.01% vs. 33.69%, p=0.048). The ratio of CD4+/CD8+ T lymphocytes was also higher in the ginseng group (2.03 vs. 1.28, p=0.027). Neutropenia and liver dysfunction prevalence did not differ between the groups. CONCLUSION: The ginseng group, which received Korean Red ginseng daily during adjuvant chemotherapy, showed higher levels of CD4+ T lymphocytes and CD4+/CD8+ T lymphocyte ratio after chemotherapy.

LASSO-Based Machine Learning Algorithm for Prediction of Lymph Node Metastasis in T1 Colorectal Cancer.

PURPOSE: The role of tumor-infiltrating lymphocytes (TILs) in predicting lymph node metastasis (LNM) in patients with T1 colorectal cancer (CRC) remains unclear. Furthermore, clinical utility of a machine learning-based approach has not been widely studied. MATERIALS AND METHODS: Immunohistochemistry for TILs against CD3, CD8, and forkhead box P3 in both center and invasive margin of the tumor were performed using surgically resected T1 CRC slides. Three hundred and sixteen patients were enrolled and categorized into training (n=221) and validation (n=95) sets via random sampling. Using clinicopathologic variables including TILs, the least absolute shrinkage and selection operator (LASSO) regression model was applied for variable selection and predictive signature building in the training set. The predictive accuracy of our model and the Japanese criteria were compared using area under the receiver operating characteristic (AUROC), net reclassification improvement (NRI)/integrated discrimination improvement (IDI), and decision curve analysis (DCA) in the validation set. RESULTS: LNM was detected in 29 (13.1%) and 12 (12.6%) patients in training and validation sets, respectively. Nine variables were selected and used to generate the LASSO model. Its performance was similar in training and validation sets (AUROC, 0.795 vs. 0.765; p=0.747). In the validation set, the LASSO model showed better outcomes in predicting LNM than Japanese criteria, as measured by AUROC (0.765 vs. 0.518, p=0.003) and NRI (0.447, p=0.039)/IDI (0.121, p=0.034). DCA showed positive net benefits in using our model. CONCLUSION: Our LASSO model incorporating histopathologic parameters and TILs showed superior performance compared to conventional Japanese criteria in predicting LNM in patients with T1 CRC.

Specific protein 1(SP1) regulates the epithelial-mesenchymal transition via lysyl oxidase-like 2(LOXL2) in pancreatic ductal adenocarcinoma.

Specific protein 1 (SP1) is associated with aggressive behavior, invasive clinical phenotype and poor clinical outcomes in various cancers. We studied whether SP1 exerts its effect on invasiveness and promotion of the epithelial-mesenchymal transition (EMT) by regulating lysyl oxidase-like 2 (LOXL2) in pancreatic ductal adenocarcinoma (PDAC) cell lines. We showed that silencing of SP1 in MIA Paca-2 cell significantly decreased cell invasion and migration. In MIA Paca-2 cells, silencing of SP1 induced a reduction of LOXL2 expression, whereas LOXL2 silencing did not lead to a decrease in the expression of SP1. Chromatin immunoprecipitation assay demonstrated the binding of SP1 to LOXL2 promoter. Wound healing and transmigration assays also showed that transfection of both SP1 and LOXL2 siRNA induced most significant decrease of cell invasion and migration compared to either SP1 or LOXL2-only silenced cells. Finally, we investigated the prognostic value of SP1 in patients with PDAC and SP1/LOX2 expression was examined by immunochemistry. Univariate and multivariate analyses showed that tumor differentiation and co-expression of SP1 and LOXL2 were independent factors for disease-free survival. In summary, our study demonstrates that SP1 modulates EMT and is involved in tumor invasion and migration of PDAC cells through the regulation of LOXL2.

Clinical application of invalid foods using mealworms and evaluation of nutrition status and immune function: a study protocol for a randomized, double blind, placebo-controlled trial.

BACKGROUND: Protein intake is important for the recovery of the immune system, physical strength, and wound healing after surgery. Sarcopenia is associated with a poor prognosis when compared to patients without sarcopenia in cancer patients. Recently, edible insects, such as mealworms, have been recognized as having a high protein content. In this study, we will evaluate the effect of nutritional status and immune function change based on a patient's ingestion of mealworms after hepatobiliary pancreatic surgery. METHODS/DESIGN: This is a prospective, two-armed, phase III study investigating the effect of mealworm improving nutrition and immune status in patients after hepatobiliary pancreatic surgery. In the trial group, the patients will be provided with mealworms for 2 months after surgery. In the control group, patients will be provided with grain powder for 2 months after surgery. The target for accrual is 168 patients. We divided in to three groups according to the type of surgery. DISCUSSION: The primary endpoint is to evaluate body cell mass index 2 months postoperatively. Secondary endpoints include other body composition changes as well as nutrition index and immune function change. We expect that ingestion of mealworms can effectively improve the nutritional status and enhance the immune function. Mealworm can be used effectively for nutritional management of patients after surgery. TRIAL REGISTRATION: Clinicaltrials.gov NCT03201926 Registered June 28, 2017, retrospectively registered.

Impact of prior abdominal surgery on postoperative prolonged ileus after ileostomy repair.

BACKGROUND AND AIMS: Postoperative ileus (POI) is one of the most common reasons for sustained hospital stays after ileostomy repair. Although many factors have been investigated as POI risk factors, the investigation of the impact of prior abdominal surgery (PAS) before rectal cancer surgery has been limited. This study aimed to identify the impact of PAS as a risk factor for POI after ileostomy repair. MATERIAL AND METHODS: A total of 220 consecutive patients with rectal cancer who underwent ileostomy repair were enrolled. The patients were divided into PAS-positive and PAS-negative groups according to the history of PAS before rectal cancer surgery. Univariate and multivariate analyses were performed to identify the clinicopathological factors associated with POI. RESULTS: The PAS-positive group had a longer operation time (111 min vs. 93.4 min, p=0.029) and a greater length of hospital stay (10 days vs. 7.8 days, p=0.003) compared with the PAS-negative group. POI was more frequent in the PAS-positive group (23.1% vs. 6.2%, p=0.011). The POI rate in the entire cohort was 8.1%. The repair method (stapled side-to-side vs. hand-sewn end-to-end, odds ratio OR=3.6, 95% confidence interval CI=1.2-11.1, p=0.022) and PAS (odds ratio=4.0, 95% confidence interval=1.2-12.8, p=0.017) were significant predictors of POI in the multivariate analysis. CONCLUSIONS: This study suggests that PAS before rectal cancer surgery is associated with POI after ileostomy repair.

Impact of Pre-Transplant Bacterial Infections on Post-Operative Outcomes in Patients after Liver Transplantation.

BACKGROUND: In contrast to studies evaluating the negative effect of bacterial infections on clinical outcomes after liver transplantation, there is little evidence with regard to pre-transplant bacterial infections. We aimed to investigate the impact of pre-transplant bacterial infections on post-transplant outcomes in patients after liver transplantation. PATIENTS AND METHODS: We retrospectively analyzed clinical data from 33 consecutive patients who underwent primary liver transplantations. Patients were divided into two groups based on the occurrence of a bacterial infection within the 30 days before transplantation. RESULTS: Of the 33 patients, 23 patients did not have pre-transplant bacterial infections, while 10 patients did have pre-transplant bacterial infections. Pre-transplant bacterial infections were urinary tract infections (n = 4), spontaneous bacterial peritonitis (n = 3), and one each of pneumonia, bacteremia, and cellulitis. There were no differences in clinical characteristics between the two groups. Post-operative clinical outcomes, including post-operative bacterial infection, intensive-care unit re-admission, 30-day re-hospitalization, and 90-day mortality rate were not significantly different between the two groups. The two-year overall survival rate was 76.7% in patients with pre-transplant infections and 80.0% in those without pre-transplant infections. CONCLUSIONS: Patients with pre-transplant bacterial infections did not have inferior clinical outcomes, compared with those without pre-transplant bacterial infections.

Which patients with intestinal obstruction need surgery? The delta neutrophil index as an early predictive marker.

PURPOSE: Predicting the need for surgical intervention among patients with intestinal obstruction is challenging. The delta neutrophil index (DNI) has been suggested as a useful marker of immature granulocytes, which indicate an infection or sepsis. In this study, we evaluated the impact of the DNI as an early predictor of operation among patients with intestinal obstruction. METHODS: A total of 171 patients who were diagnosed with postoperative intestinal obstruction were enrolled in this study. Medical records, including data for the initial CRP level, WBC count, and DNI were reviewed. Receiver operating characteristic (ROC) curves were generated to clarify the optimal DNI cutoff values for predicting an operation. RESULTS: Among the 171 patients, 38 (22.2%) needed surgical intervention. The areas under the initial CRP, WBC, and DNI ROC curves were 0.460, 0.449, and 0.543, respectively. The optimal cutoff value for predicting further surgical intervention according to the initial DNI level was 4.3%. The accuracy of the cutoff value was 74.9%, the sensitivity was 23.7%, and the specificity was 89.5% (positive predictive value, 23.7%; negative predictive value, 89.5%). In the multivariate analysis, initial DNI levels ≥ 4.3% were significantly associated with surgical intervention (odd ratio, 3.092; 95% confidence interval, 1.072-8.918; P = 0.037). CONCLUSION: The initial DNI level in patients with intestinal obstruction may be a useful predictor for determining the need for surgical intervention.

Multiple Myeloma Mimics Bone Metastasis From a Rectal Adenocarcinoma.

A presumptive diagnosis of bone metastasis can be easily made when a patient with a history of colorectal cancer develops bone lesions that are seen on follow-up imaging. In this case report, we describe a patient whose multiple bone lesions were wrongly attributed to a recurrence of rectal cancer rather than being identified as multiple myeloma lesions. When clinicians detect new, abnormal, bony lesions in a patient with a previous history of cancer, they should consider diseases such as multiple myeloma in their differential diagnosis.

The efficacy of cap-assisted colonoscopy performed by a single endoscopist in patients after colorectal resection.

BACKGROUND: The use of a transparent cap is regarded as a simple method to obtain better outcomes compared with standard colonoscopy. In this study, we investigated whether cap-assisted colonoscopy can improve the quality of procedure-related outcomes in patients with a history of colorectal resection. METHODS: This study was designed as a prospective, randomized, controlled trial conducted at a single tertiary center by a single endoscopist (Kang J.). A total 183 patients after colorectal resection due to primary colorectal cancer were enrolled and 1:1 randomized to undergo either cap-assisted colonoscopy (CAP group) or standard colonoscopy (non-CAP group). The primary endpoint was the comparison of cecal intubation time between the 2 groups. RESULTS: The mean cecal intubation time of the CAP group (n = 89) was significantly shorter than that of the non-CAP group (n = 89) (538 seconds vs 677 seconds, P = 0.024). In the CAP group, the endoscopist performed faster intubation than average more often compared with the non-CAP group (71.9% vs 57.3%). In regard to moving average curve, the CAP group showed a gentle slope during the learning period, while the non-CAP group showed a steep decrease. CONCLUSION: The cap-assisted colonoscopy could reduce cecal intubation time and achieve more frequent faster intubation compared with standard colonoscopy in patients after colorectal resection.

In Vitro Adenosine Triphosphate-Based Chemotherapy Response Assay as a Predictor of Clinical Response to Fluorouracil-Based Adjuvant Chemotherapy in Stage II Colorectal Cancer.

PURPOSE: We evaluated the usefulness of the in vitro adenosine triphosphate-based chemotherapy response assay (ATP-CRA) for prediction of clinical response to fluorouracil-based adjuvant chemotherapy in stage II colorectal cancer. MATERIALS AND METHODS: Tumor specimens of 86 patients with pathologically confirmed stage II colorectal adenocarcinoma were tested for chemosensitivity to fluorouracil. Chemosensitivity was determined by cell death rate (CDR) of drug-exposed cells, calculated by comparing the intracellular ATP level with that of untreated controls. RESULTS: Among the 86 enrolled patients who underwent radical surgery followed by fluorouracil-based adjuvant chemotherapy, recurrence was found in 11 patients (12.7%). The CDR ≥ 20% group was associated with better disease-free survival than the CDR < 20% group (89.4% vs. 70.1%, p=0.027). Multivariate analysis showed that CDR < 20% and T4 stage were poor prognostic factors for disease-free survival after fluorouracil-based adjuvant chemotherapy. CONCLUSION: In stage II colorectal cancer, the in vitro ATP-CRA may be useful in identifying patients likely to benefit from fluorouracil-based adjuvant chemotherapy.

Clinical implications of microsatellite instability in T1 colorectal cancer.

PURPOSE: The estimation of regional lymph node metastasis (LNM) risk in T1 colorectal cancer is based on histologic examination and imaging of the primary tumor. High-frequency microsatellite instability (MSI-H) is likely to decrease the possibility of metastasis to either regional lymph nodes or distant organs in colorectal cancers. This study evaluated the clinical implications of MSI in T1 colorectal cancer with emphasis on the usefulness of MSI as a predictive factor for regional LNM. MATERIALS AND METHODS: A total of 133 patients who underwent radical resection for T1 colorectal cancer were included. Genomic DNA was extracted from normal and tumor tissues and amplified by polymerase chain reaction (PCR). Five microsatellite markers, BAT-25, BAT-26, D2S123, D5S346, and D17S250, were used. MSI and clinicopathological parameters were evaluated as potential predictors of LNM using univariate and multivariate analyses. RESULTS: Among 133 T1 colorectal cancer patients, MSI-H, low-frequency microsatellite instability (MSI-L), and microsatellite stable (MSS) colorectal cancers accounted for 7.5%, 6%, and 86.5%, respectively. MSI-H tumors showed a female predominance, a proximal location and more retrieved lymph nodes. Twenty-two patients (16.5%) had regional LNM. Lymphovascular invasion and depth of invasion were significantly associated with LNM. There was no LNM in 10 MSI-H patients; however, MSI status was not significantly correlated with LNM. Disease-free survival did not differ between patients with MSI-H and those with MSI-L/MSS. CONCLUSION: MSI status could serve as a negative predictive factor in estimating LNM in T1 colorectal cancer, given that LNM was not detected in MSI-H patients. However, validation of our result in a different cohort is necessary.

Underweight body mass index as a predictive factor for surgical site infections after laparoscopic appendectomy.

PURPOSE: Analyses of risk factors associated with surgical site infections (SSIs) after laparoscopic appendectomy (LA) have been limited. Especially, the association of an underweight body mass index (BMI) with SSIs has not been clearly defined. This study aimed to identify the impact of underweight BMI in predicting SSIs after LA. MATERIALS AND METHODS: The records of a total of 101 consecutive patients aged ≥16 years who underwent LA by a single surgeon between March 2011 and December 2012 were retrieved from a prospectively collected database. The rate of SSIs was compared among the underweight, normal and overweight and obese groups. Also, univariate and multivariate analyses were performed to identify the factors associated with SSIs. RESULTS: The overall rate of SSIs was 12.8%. The superficial incisional SSI rate was highest in the underweight group (44.4% in the underweight group, 11.0% in the normal group, and 0% in the overweight and obese group, p=0.006). In univariate analysis, open conversion and being underweight were determined to be risk factors for SSIs. Underweight BMI was also found to be a significant predictor for SSIs in multivariate analysis (odds ratio, 10.0; 95% confidence interval, 2.0-49.5; p=0.005). CONCLUSION: This study demonstrated underweight BMI as being associated with SSIs after LA. Surgeons should be more cautious to prevent SSIs in patients that are underweight when performing LA.