Gross morphologic features of surgical specimen in rectal cancer patients with pathological complete response following neoadjuvant chemoradiotherapy: A cross-sectional study.

BACKGROUND: pathological complete response (pCR) is achieved in 10%-30% of rectal cancer patients following neoadjuvant chemoradiotherapy and surgery. Residual mucosal abnormalities, which make patients ineligible for nonoperative management, may not be an accurate indicator of the pCR. The purpose of this study was to report the gross findings of rectal cancer patients with pathological complete responses. METHODS: This study was conducted at Tehran University of Medical Sciences, Tehran, Iran. A total of 130 patients with rectal adenocarcinoma, treated by neoadjuvant chemoradiotherapy, followed by surgical resection between March 2007, and March 2017, with a surgical pathology report of pCR, were included. Patients' demographics and pretreatment tumor characteristics were collected from the medical records. Data regarding residual mucosal abnormalities were extracted from postoperative surgical pathology reports. Abnormal findings were reported as "ulcer" or " non-ulcerative lesion". RESULTS: One hundred and fifteen patients (88.5%; 95% CI: 81.7%-93.4%) had at least one abnormal finding in the gross examination, including ulcer or non-ulcerative lesion (any mucosal abnormalities other than ulcers, including polyps, telangiectasia, etc.). Patients with higher-stage tumors had a higher chance of having an ulcerative lesion (p = 0.05). Younger patients tended to have deeper layers of involvement (p = 0.013). Patients with different gross findings were not significantly different regarding baseline characteristics, except for the pretreatment stage, where patients with a higher stage had higher odds of having ulcerative lesions. CONCLUSIONS: Most rectal cancer patients achieving a pCR exhibit abnormalities on gross examination. The higher pretreatment stages were significantly associated with gross abnormalities especially ulcers.

Comparison of hand-sewn anterior repair, resection and hand-sewn anastomosis, resection and stapled anastomosis techniques for the reversal of diverting loop ileostomy after low anterior rectal resection: a randomized clinical trial.

BACKGROUND: Low anterior resection in patients with rectal cancer may require a defunctioning loop ileostomy formation that requires closure after a period of time. There are three common techniques for ileostomy closure: anterior repair (AR or fold-over closure), resection and hand-sewn anastomosis (RHA), and resection and stapled anastomosis (RSA). We aimed to compare them on the basis of operative and postoperative features. METHODS: Patients with rectal cancer who underwent low anterior resection without complications were included in this study and randomly assigned to three parallel groups to undergo loop ileostomy closure via either AR, RHA, or RSA. Early and late outcomes were gathered from all included patients. RESULTS: Among 93 patients with a mean age of 56.21 ± 11.78 years, consisting of 58 (62.4%) men, 31 patients underwent AR, 30 patients RHA, and 32 patients RSA. There was no significant difference among the groups regarding the frequency and location of intraoperative injuries (P = 0.157). The AR groups demonstrated significantly less consumption of gauzes following intraoperative bleeding compared to the two others groups. The results showed that the duration of surgery in the RSA was significantly shorter than in the AR or RHA group (both P < 0.001). Regarding postoperative course, only one case of hematoma and two cases of surgical wound infection occurred in the RHA group. Anastomotic leakage and complete or partial obstruction did not occur in any group of patients. Latent postoperative complications did not occur in any group of patients. The median time between surgery and discharge as well as the interval until first gas passage, first defecation, oral tolerated liquid diet, as well as oral tolerated soft and regular diet in the AR group were significantly lower than in the two other groups (both P < 0.001). However, there was no statistical difference in these intervals between the RHA and RSA groups. CONCLUSIONS: Resection and stapled anastomosis had the shortest duration among the three techniques; however, anterior repair had faster recovery, including earlier tolerated oral diet, gas passing and defecation, and discharge, in comparison with the other techniques. TRIAL REGISTRATION: Trial registration number IRCT20120129008861N5.

The impact of circular stapler size on the risk of anastomotic stricture following total mesorectal excision in rectal cancer patients: A retrospective cross-sectional study.

Introduction: Colorectal cancer (CRC) surgery complications are a major issue affecting morbidity and mortality rates. Anastomotic stricture, which occurs in almost 30% of patients after surgery for rectal cancer, is one of the most serious but underreported side effects. In this study, we tried to assess the effect of stapler size on anastomotic stricture rate. Materials and Methods: At our facility, all patients underwent low anterior resections (LAR) performed using an open laparotomy technique. A contour-curved stapler and an end-to-end anastomosis (EEA) circular stapler were used in the double stapling technique (DST). All patients also underwent a protective loop ileostomy. Patients who developed stricture following leakage were excluded. Results: This study comprised a total of 173 rectal cancer patients. A 29-mm circle stapler was used to anastomose 77 patients (44.5%), while a 31-mm circular stapler was used to anastomose 96 patients (55.5%). Six individuals experienced strictures; two had a 29 mm stamper and four (4.4%) had a 31 mm one. There was no significant difference between the two groups (p:0.575). On aggregate, 8 patients experienced leakage; 3 (3.8%) of these patients received treatment with a 29 mm stapler, whereas 5 (5.2%) received treatment with a 31 mm stapler. Conclusion: this study found no statistically significant difference in the stricture rates and stapler size. The findings of this study provide credibility to the notion that in rectal cancer patients having LAR, strictures can be safely avoided by performing the anastomoses with both staplers.

Biomedical properties and hemostatic efficacy of polyvinyl alcohol (PVA) based hydrogel in experimental rat liver injury model.

PURPOSE: Bleeding is a leading cause of mortality and morbidity in the trauma and surgery field, using effective hemostatic agents can help us reduce bleeding especially in parenchymal hemorrhage. Nowadays polyvinyl alcohol (PVA) is known as a safe candidate for wound dressing and maybe a hemostatic agent. PVA-based hydrogel is a popular biocompatible material in the biomedical field especially when it has high water absorption. In this study, we investigated the PVA hydrogel's mechanical and biological properties as well as its hemostatic potential in parenchymal bleeding. METHODS: PVA hydrogel had made by the freeze-thawing approach, we used PVA hydrogel in comparison to standard treatment to investigate hemostatic potency. Also, we performed MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) tests to survey PVA cellular toxicity. After an acute liver injury, two groups of 12 rats were treated with PVA hydrogel or standard treatment with sterile gauze. The results including the time and volume of bleeding, and the time and survival rate of the rats were measured and compared. RESULTS: We saw that PVA hydrogel was safe with no cellular toxicity in the MTT assay. Regarding efficacy, PVA hydrogel increased rats' survival after bleeding from 75% to 91.7%, and decreased bleeding time (p: 0.015), and bleeding volume (p: 0.03) compared to the control group. CONCLUSION: Polyvinyl alcohol is safe. It has good biological properties with no cellular toxicity and has a significant hemostatic effect and can be regarded in control of parenchymal hemorrhage.

Evaluation of the Farsi-translated Hemorrhoidal Disease Symptom Score and Short Health Scale questionnaires in patients with hemorrhoid disease: A cross-sectional study.

Background and Aims: The Hemorrhoidal Disease Symptom Score (HDSS) is a tool that is scored based on five main symptoms: pain, bleeding, itching, soiling, and prolapse. Furthermore, the Short Health Scale (SHS) is a measurement tool of subjective health and health-related quality of life. This study was performed to validate the Farsi-translated Hemorrhoidal Disease Symptom Score (HDSS), and Scale Short Health Scale adapted for hemorrhoidal disease (SHS-HD) as a measure of symptom severity in patients with hemorrhoid disease. Methods: In this study, HDSS and SHS-HD were translated into Farsi. Participants with confirmed hemorrhoid disease completed the questionnaire. Subsequently, the questionnaire's discriminative validity, convergent validity, reliability, sensitivity, and specificity were evaluated. Results: Data from 31 patients were analyzed (mean age 39.68; 71% male). The results of the analysis showed good internal consistency as Cronbach's α for HDSS and SHS were 0.994 and 0.995 respectively. Spearman's correlation coefficient for the test-retest comparison was 0.986 (p < 0.01). The responses demonstrated good convergent validity. Moreover, the comprehension and suitability of each question were rated as excellent (Pearson's correlation coefficient = 0.3). Conclusions: Our findings revealed that the Farsi translation of the HDSS and SHS-HD can be a valuable tool for evaluating the symptom severity in patients with hemorrhoid disease.

Translation, cross-cultural adaptation, and psychometric evaluation of the Persian (Farsi) version of the QoLAF (quality of life in patients with anal fistula) questionnaire.

INTRODUCTION: The effective treatment of anal fistulas almost always requires surgical intervention, which could be accompanied by post-operative complications, and affect the quality of life of patients. This study aimed to cross-culturally adapt the Persian version of the Quality of Life in patients with Anal Fistula questionnaire and evaluate its validity and reliability. MATERIALS AND METHODS: Sixty patients with a mean age of 44 years ranging from 21 to 72 years entered the study. Forty-seven participants were men, and thirteen were women. After performing a scientific translation of the questionnaire based on Beaton's guidelines for cross-cultural adaptation and after extensive reviews by experts and specialists, the final version of the questionnaire was obtained. Then, 60 questionnaires (100%) were filled out by the participants (n = 60) and retrieved during a 7 to 21-day period. Data were collected and analyzed. Finally, according to the obtained data, the validity and reliability of the questionnaire were calculated. RESULTS: Cross-cultural adaptation of the translated questionnaire was verified by the expert committee. The results showed perfect internal consistency (Cronbach alpha = 0.842), and external consistency (intraclass correlation coefficient = 0.800; P<0.001). Spearman correlation coefficient between test and retest was reported to be 0.980 (P-value <0.01), confirming the temporal stability of the translated questionnaire. The interrater reliability based on Cohen's kappa coefficient also demonstrated a perfect degree of agreement between two peer variables (Kappa = 0.889; P<0.001). CONCLUSION: The Persian translation of the Quality of Life in patients with the Anal Fistula questionnaire was proven to be valid and reliable for the evaluation of the QoL of patients with anal fistula.

Assessment of the efficacy of Handmade Vacuum-Assisted Sponge Drain for Treatment of Anastomotic leakage after Low Anterior Rectal Resection.

Anastomotic leakage is one of the major complications of colorectal surgery, which might lead to reoperation, increased hospital stays, further intervention and mortality. Vacuum-assisted closure by devices such as Endo-SPONGE® produced by (B-Braun Medical B.V.) is currently being used to treat leakage and fistula. In this study, we aimed to assess the handmade vacuum-assisted sponge drain for anastomotic leakage following low anterior resection. This prospective study included 22 patients who had undergone sponge drain placement to treat anastomotic leakage. All patients had anastomotic leaks or defects after left anterior rectal resection (LAR) without ileostomy. They were treated with neo-adjuvant chemotherapy before the surgery and then subjected to rigid recto-sigmoidoscopy for 30 days following the operation. Any sign of leakage, such as perianal and pelvic pain, was immediately identified and followed up with a CT scan and another recto-sigmoidoscopy. Twenty-two patients were enrolled in this study, 12 men (54.5%) and 10 women (47.4%). All patients had received neo-adjuvant chemotherapy with an average follow-up of 22.30 ± 3.81. 75% of patients (15 cases) were successfully treated, and 17 patients (85%) underwent successful ostomy closure. Treatment failed in 5 patients (25%), including three men and two women. This study shows that handmade vacuum-assisted sponge drain is a cost-effective method of anastomotic leakage management with efficacy similar to that of Endo-SPONGE®.

Safety and efficacy of injection of human placenta mesenchymal stem cells derived exosomes for treatment of complex perianal fistula in non-Crohn's cases: Clinical trial phase I.

BACKGROUND AND AIM: A perianal fistula is an abnormal tract that connects anal canal to skin. Current medical and surgical interventions have a high failure rate particularly in complex and refractory cases. MSC-derived exosomes have demonstrated immunomodulatory effects without the conventional complications; hence, in this study, we evaluated the safety of their application for complex perianal fistula. METHODS: Placenta-derived MSCs were cultured, and exosomes were isolated using ultracentrifugation. Exosome injections were administered in the operating room to 11 patients with complex perianal fistula (presence of fistulas for at least 1 year alongside medical and surgical treatment). The patients were followed for 6 months, and the patients were evaluated using physical examination, face-to-face interviews, and magnetic resonance imaging (MRI). RESULTS: Among 11 patients only one did not show any improvement upon physical examination. Five patients showed complete tract resolve. While the discharge was stopped in eight patients, two patients showed only reduction. None of the patients showed any acute or latent allergic reaction or injection related complications. CONCLUSION: Administration of exosomes isolated from MSCs demonstrates safety and a satisfactory therapeutic effect in treatment complex perianal fistulae; therefore, it can be a candidate for future studies and might play a significant role in treatment.

Hand-sewn direct repair versus resection and hand-sewn anastomosis techniques for the reversal of diverting loop ileostomy after lower anterior rectal resection surgery: A randomized clinical trial.

INTRODUCTION: Several techniques have been proposed for the closure of loop ileostomy. This is the first study comparing bowel function and outcomes of two different hand-sewn surgical techniques used for the closure of diverting protective loop ileostomy. METHOD: In this prospective, randomized, double-blind clinical trial, 40 patients with a history of rectal cancer, low anterior resection, and diverting loop ileostomy who were candidates for ileostomy reversal were included and randomly assigned into two groups, hand-sewn direct repair of the ileal defect (group A) and resection and hand-sewn anastomosis of the ileum (group B). RESULTS: The mean age of patients was 56.42 and 52.10 years in groups A and B, respectively. Regarding early postoperative period, group A developed earlier first gas passage (1.68 vs. 2.25 days, p = 0.041) and stool passage (2.10 vs. 2.80 days, p = 0.032). Group A also revealed shorter operating time (83.68 vs. 89.50 min, p = 0.040) and hospital stay (4.73 vs. 6.80 days, p = 0.001). None of the participants in both groups developed signs of bowel obstruction during the early and late postoperative follow-up period. CONCLUSIONS: Direct hand-sewn repair for the closure of diverting loop ileostomy is a safe technique with better postoperative bowel function, oral diet tolerance, and less hospital stay compared to resection and hand-sewn anastomosis of the ileum.

Prognostic Factors of Disease Recurrence and Overall Survival Following Curative Resection of Colon Cancer: A 10-year Cohort from a Referral Center.

Background: The growing incidence of colorectal cancer around the world highlights the significance of tumor recurrence and patient survival as 2 key elements of patient therapy. We aimed to study the factors linked with disease recurrence and survival in colon cancer. Methods: Patients with colon cancer who underwent tumor excision as their primary treatment were enrolled in this prospective cohort and monitored for 10 years. Various demographic and clinicopathologic factors of these patients were studied in association with the 2 primary outcomes of this study, including tumor recurrence and patient survival. Statistical tests and survival analysis were utilized to explore the study aims. Results: An overall number of 113 patients were included in this survey with a mean age of 54.7 (±SD, 14.1), and most of the patients were men (56.6%). The mean follow-up period was 28.3 (±25.5) months. Tumor recurrence occurred in 32 (28.3%) patients in the study period. The estimated mean survival of patients was 54.9 (95% CI, 45.3-64.4) months. N staging ( p = 0.036), T staging ( p = 0.009), and pathologic staging (P = .004) were the significant pathological factors to higher tumor recurrence and lower survival rates. Conclusion: Advanced tumor staging led to increased disease recurrence and lower survival of colon cancer patients in this survey. Further public health screening and education programs are needed to improve the early detection and prognosis of these patients in Iran.

Evaluating the safety and efficacy of mesenchymal stem cell-derived exosomes for treatment of refractory perianal fistula in IBD patients: clinical trial phase I.

Background: Exosome administration is a novel medical approach that promises excellent immunomodulatory properties without the conventional side effects of current antitumor necrosis factor drugs and stem cells. This study aimed to assess the safety and efficacy of using mesenchymal stem cell (MSC) exosomes to treat refractory fistulas in patients with inflammatory bowel disease. Methods: MSCs were derived from the umbilical cords and their exosomes were isolated. Five patients with refractory perianal Crohn's disease fistulas with a median age of 35 years (range 31-47 years) were enrolled in the study. Exosome injections were administered in the operating room to patients with refractory fistula (fistulas that are irresponsive to anti-tumor necrosis factor-α administration within 6 months). Six months later, a physical examination, face-to-face interviews, and magnetic resonance imaging were employed to evaluate the therapy responses of patients. Results: The outcomes within 6 months after initiation of therapy showed that four patients had responded to therapy. Three patients who received exosome injections exhibited complete healing, while one reported no improvement and active discharge from the fistula site. In addition, five patients (100%) reported neither systemic nor local adverse effects. Conclusions: Injection of exosomes extracted from MSCs demonstrates safety and a satisfactory therapeutic effect, as evidenced in this and other studies, and may play a significant role in the future treatment of gastrointestinal fistulas.

Surgical management of retrorectal tumors: a single-center 12 years' experience.

Purpose: Retrorectal tumors (RTs) are rare tumors that arise in the space between the mesorectum and the pelvic wall and often originate in embryonic tissues. The primary treatment for these tumors is complete excision surgery, and choosing the best surgical approach is very important. Methods: In this study, we retrospectively collected the data of 15 patients with RTs who underwent surgery in the surgical ward of Imam Khomeini Hospital in Tehran for 12 years to share our experiences of patients' treatment and compare different surgical approaches. Results: A total of 5 tumors were malignant, 10 were benign, and most of the tumors were congenital. Malignant tumors were seen in older patients. Three surgical procedures were performed on patients. Three patients underwent abdominal approach surgery, and 8 patients underwent posterior surgery. A combined surgical approach was performed on 4 patients. Two patients underwent laparoscopic surgery. The abdominal approach had the least long-term complication, and the combined approach had the most complications; laparoscopic surgery reduced the length of hospital stay and complications after surgery. Conclusion: A multidisciplinary team collaboration using magnetic resonance imaging details is necessary to determine a surgical treatment approach. It could reduce the need for a preoperative biopsy. However, every approach has its advantages and disadvantages. In the main, they have no superiority over each other, and individualized treatment is the key.

The potential of PIK3CA, KRAS, BRAF, and APC hotspot mutations as a non-invasive detection method for colorectal cancer.

BACKGROUND: Early diagnosis of colorectal cancer (CRC) can lead to prompt treatment modalities. Circulating cell-free DNA (cfDNA) analysis provides an alternative non-invasive procedure for the study of the molecular profiles of the corresponding tumor tissue. In this study, we aimed to investigate PIK3CA, KRAS, BRAF, and APC hotspot mutations in CRC tumor tissue, besides evaluating the diagnostic performance of KRAS, BRAF, and PIK3CA mutations in the plasma cfDNA. METHOD: Primary CRC tissue samples and paired plasma samples were collected from 70 patients. After DNA extraction, PCR-direct sequencing was used to screen for mutations in PIK3CA exon 9 and APC exon 15 in tumor tissues. Amplification Refractory Mutation System (ARMS)-quantitative PCR (qPCR) was used to evaluate KRAS codon 12 and 13, BRAF V600E, and PIK3CA exon 9 hotspot mutations. RESULTS: PIK3CA exon 9 hotspot mutations were detected in 47.1% of tumor tissues and 20% of paired plasma cfDNA samples by ARMS-qPCR method, while Sanger sequencing did not identify any mutation in PIK3CA exon 9. The KRAS exon 2 mutations were detected in 71.4% and 34.3% of tumor tissue samples and paired plasma cfDNA respectively. BRAF V600E mutation was observed in 17.1% and 4.3% of tissue DNA and plasma cfDNA respectively. A panel of PIK3CA, KRAS, and BRAF showed a sensitivity of 61% and a specificity of 100% (AUC = 0.803). APC hotspot mutations were observed in 76.8% of CRC tissue samples. APC mutations were not analyzed in the plasma samples. The co-existence of KRAS/PIK3CA/APC gene mutations encompassed the highest frequency among all combinations of mutations. BRAF and PIK3CA mutations were significantly more frequent in older patients. CONCLUSION: We demonstrated that a panel consisting of PIK3CA, KRAS, and BRAF mutations showed good diagnostic performance for detecting CRC in the plasma cfDNA.

Methylation of FBN1, SPG20, ITF2, RUNX3, SNCA, MLH1, and SEPT9 genes in circulating cell-free DNA as biomarkers of colorectal cancer.

BACKGROUND: Investigating aberrant tumor-specific methylation in plasma cell-free DNA provides a promising and noninvasive biomarker for cancer detection. OBJECTIVE: We aimed to investigate methylation status of some promoter regions in the plasma and tumor tissues to find biomarkers for early detection of colorectal cancer. METHODS: This case-control study on seventy colorectal cancer patients and fifty matched healthy controls used Methylation-Specific High-Resolution Melting Curve analysis to evaluate the methylation of the selected promoter regions in converted genomic tissue DNA and plasma cfDNA. RESULTS: The methylation levels in selected regions of SPG20 (+24375 to +24680, +24209 to +24399, and +23625 to +23883), SNCA (+807 to +1013, +7 to +162, and -180 to +7), FBN1 (+223 to +429, +1 to +245, and -18 to -175), ITF2 (+296 to +436 and -180 to +55), SEPT9 (-914412 to -91590 and -99083 to -92264), and MLH1 (-13 to +22) were significantly higher in tumor tissues compared with normal adjacent tissues. The methylation levels of FBN1, ITF2, SNCA, and SPG20 promoters were significantly higher in the patient's plasma compared to patient's normal tissue and plasma of healthy control subjects. FBN1, SPG20, and SEPT9 promoter methylation had a good diagnostic performance for discriminating CRC tissues from normal adjacent tissues (AUC > 0.8). A panel of SPG20, FBN1, and SEPT9 methylation had a higher diagnostic value than that of any single biomarker and other panels in tissue-based assay (AUC > 0.9). The methylation of FBN1(a) and SPG20(a) regions, as the closest region to the first coding sequence (CDS), had a good diagnostic performance in plasma cfDNA (AUC > 0.8) while a panel consisted of FBN1(a) and SPG20(a) regions showed excellent diagnostic performance for CRC detection in plasma cfDNA (AUC > 0.9). CONCLUSION: Methylation of FBN1(a) and SPG20(a) promoter regions in the plasma cfDNA can be an excellent simple, non-invasive blood-based test for early detection of CRC.

Introduction of a handmade vacuum-assisted sponge drain for the treatment of anastomotic leakage after low anterior rectal resection.

PURPOSE: Anastomotic leakage, a known major postoperative complication, potentially leads to readmission, reoperation, and increased mortality rates in patients, such as rectal cancer patients following a low anterior resection (LAR). Currently, vacuum-assisted closure, as featured by B-Braun (B-Braun Medical B.V.), is already being used for the treatment of gastrointestinal leakages and fistulas. The main aim of this study was to introduce a novel method for creating a vacuum-assisted drain for the treatment of anastomotic leakage after LAR. METHODS: All 10 patients, who underwent LAR surgery from 2018 to 2019, were diagnosed with anastomotic leakage and had received neoadjuvant chemotherapy prior to surgery. Therefore, patients were treated with a handmade vacuum-assisted drain and were revisited every 5 to 7 days for further evaluations and drain replacement until leakage resolution. Physical features of cavity, time of diagnose, and duration of treatment were analyzed correspondingly. The handmade vacuum-assisted sponge drain was prepared for each patient in each session of follow-up. RESULTS: Eight out of 10 patients experienced complete closure of the defect. The mean delay time from the day of operation to the diagnosis of anastomotic leakage was 61.0±80.4 days while the mean time for leakage closure was 117.6±68.3 days. Eventually, 7 cases underwent ileostomy reversal with no complications during a 3-month follow-up. CONCLUSION: In this study, we evaluated the healing process of anastomotic leakage after the usage of a handmade vacuum-assisted sponge drain in a case series method. In our trial, we provided an innovative cost-benefit method easily applicable in the operating room.

Improved microsatellite instability detection in colorectal cancer patients by a combination of fourteen markers especially DNMT3a, DCD, and MT1X.

BACKGROUND: Microsatellite instability (MSI) results from genetic and epigenetic changes. Studying Microsatellite instability can help in treatment and categorization of colorectal cancer (CRC) patients. OBJECTIVES: We aimed to investigate whether 14 genomic markers consisting of BAT-62, BAT-60, BAT-59a, BAT-56a, BAT-56b, DCD, RIOX, RNF, FOXP, ACVR, CASP2, HSP110, MT1X, and DNMT3a can increase the detection rate of MSI in CRC. METHODS: Samples were stratified by pentaplex panel (Promega) and 14 markers using multiplex PCR and fragment analysis. In MSI+ samples, to identify the pattern of BRAF V600E mutation and MLH1 promoter methylation, ARMS-scorpion, and Methylation-Specific High-Resolution Melting Curve analysis, were applied respectively. RESULTS: Totally, 35 MSI+ cases identified by 14 marker panel. Only 18 cases of them were detected by both panels which are pentaplex and 14 marker. On the other hand, 17 new MSI+ cases just were identified by 14 markers panel. The highest diagnostic value among 14 markers is related to three makers, namely DCD, MT1X, and DNMT3a. In MSI+ cases, the rate of MLH1 promoter methylation was insignificant, (P value = 0.3979) while the rate of observed BRAFV600E mutation was significantly higher (P value = 0.0002). CONCLUSION: Fourteen marker panel showed higher sensitivity in comparison with the pentaplex panel increasing the detection rate of MSI+ cases up to 1.94 fold. Three markers namely DNMT3a, DCD, and MT1X of 14 marker panel were the best among them showing excellent diagnostic value. A combination of these markers showed 100% sensitivity and specificity in the studied group. In contrary to the markers in the pentaplex panel, these markers had the ability to detect MSI without any bias for the clinicopathological features. These markers will help to identify more end-stage MSI+ tumors which are located distal colon.

Antibiotic resistance pattern of Bacteroides fragilis isolated from clinical and colorectal specimens.

BACKGROUND: Bacteroides fragilis is a part of the normal gastrointestinal flora, but it is also the most common anaerobic bacteria causing the infection. It is highly resistant to antibiotics and contains abundant antibiotic resistance mechanisms. METHODS: The antibiotic resistance pattern of 78 isolates of B. fragilis (22 strains from clinical samples and 56 strains from the colorectal tissue) was investigated using agar dilution method. The gene encoding Bacteroides fargilis toxin bft, and antibiotic resistance genes were targeted by PCR assay. RESULTS: The highest rate of resistance was observed for penicillin G (100%) followed by tetracycline (74.4%), clindamycin (41%) and cefoxitin (38.5%). Only a single isolate showed resistance to imipenem which contained cfiA and IS1186 genes. All isolates were susceptible to metronidazole. Accordingly, tetQ (87.2%), cepA (73.1%) and ermF (64.1%) were the most abundant antibiotic-resistant genes identified in this study. MIC values for penicillin, cefoxitin and clindamycin were significantly different among isolates with the cepA, cfxA and ermF in compare with those lacking such genes. In addition, 22.7 and 17.8% of clinical and GIT isolates had the bft gene, respectively. CONCLUSIONS: The finding of this study shows that metronidazole is highly in vitro active agent against all of B. fragilis isolates and remain the first-line antimicrobial for empirical therapy.

Translation, validation and psychometric evaluation of the Persian (Farsi) version of the Low Anterior Resection Syndrome Score (LARS-P).

INTRODUCTION: Low anterior resection (LAR) for rectal cancer affects bowel function after the operation, causing a group of symptoms known as LAR Syndrome (LARS). LARS score is a patient-reported questionnaire to assess bowel dysfunction after the LAR operation. This study performed to validate the Persian (Farsi) translation of the LARS score and to investigate the psychometric properties of the score. The impact of LARS on the Quality of Life (QoL) of patients was also assessed. MATERIALS AND METHODS: The LARS score was translated into Persian. Participants with a history of rectal cancer and low anterior resection were asked to complete the LARS score questionnaire. They were also asked a single question evaluating the impact of bowel function on QoL. Discriminative validity, convergent validity, sensitivity, and specificity of the questionnaire were calculated. A group of patients completed the score twice to assess the reliability of the questionnaire. RESULTS: From 358 patients with rectal cancer, 101 participants completed the Persian questionnaire. Answers of a high fraction of participants showed a moderate/perfect fit between their LARS score and their QoL. The Persian score demonstrated good convergent validity. It was able to differentiate between participants in terms of gender and T staging of the primary tumor. The score had high reliability. CONCLUSION: The Persian translation of the LARS score has excellent psychometric properties compared to previous translations in other languages. Therefore, it is a valid and reliable questionnaire to assess LARS.

Short-course versus long-course neoadjuvant chemoradiotherapy in patients with rectal cancer: preliminary results of a randomized controlled trial.

PURPOSE: Colorectal cancer is becoming an increasing concern in the middle-aged population of Iran. This study aimed to compare the preliminary results of short-course and long-course neoadjuvant chemoradiotherapy treatment for rectal cancer patients. MATERIALS AND METHODS: Patients in group I received three-dimensional conformational radiotherapy with a dose of 25 Gy/5 fractions in 1 week plus concurrent XELOX regimen (capecitabine 625 mg/m2 from day 1-5 twice daily and oxaliplatin 50 mg/m2 on day 1 once daily). Patients in group II received a total dose of 50-50.4 Gy/25-28 fractions for 5 to 5.5 weeks plus capecitabine 825 mg/m2 twice daily. Both groups underwent delayed surgery at least 8 weeks after radiotherapy completion. The pathological response was assessed with tumor regression grade. RESULTS: In this preliminary report on complications and pathological response, 66 patients were randomized into study groups. Mean duration of radiotherapy in the two groups was 5 ± 1 days (range, 5 to 8 days) and 38 ± 6 days (range, 30 to 58 days). The median follow-up was 18 months. Pathological complete response was achieved in 32.3% and 23.1% of patients in the short-course and long-course groups, respectively (p = 0.558). Overall, acute grade 3 or higher treatment-related toxicities occurred in 24.2% and 22.2% of patients in group I and II, respectively (p = 0.551). No acute grade 4 or 5 adverse events were observed in either group. Within one month of surgery, no significant difference was seen regarding grade ≥3 postoperative complications (p = 0.333). CONCLUSION: For patients with rectal cancer located 5 cm above the anal verge, short-course radiotherapy with concurrent and consolidation chemotherapy and delayed surgery is not different in terms of acute toxicity, postoperative morbidity, complete resection, and pathological response compared to long-course chemoradiotherapy.

Increasing the expression of programmed death ligand 2 (PD-L2) but not 4-1BB ligand in colorectal cancer cells.

Immune checkpoint (ICP) molecules modulate the immune response by either inducing or preventing T cell activation. Over-expression of some ICPs on malignant cells has been shown to regulate anti-tumor immune responses. We aimed to investigate the expression levels of two immune checkpoint molecules which have not been studied extensively in patients with colorectal cancer (CRC). Programmed Death Ligand 2 (co-inhibitory) and 4-1BB ligand (co-stimulatory) were assessed in tumor tissues of CRC patients compared to the adjacent normal tissues. Following tissue excision during surgical operation from 21 CRC patients, RNA extraction, cDNA synthesis and semi-quantitative real-time PCR were done for measuring the expressions of PD-L2 and 4-1BBL genes. In protein level, indirect immunohistochemistery (IHC) was performed on tissue sections. We revealed that PD-L2 was expressed in about 81% CRCs and insignificantly correlated with the tumor differentiation grade. Although a 3.25-fold change in the gene expression of PD-L2 was found in tumor tissues compared to the adjacent normal tissues (P = 0.005), but decreased level of 4-1BBL in counterpart tissues was not significant. Our results were confirmed by IHC for PDL-2 (P = 0.02) and 4-1BBL, however it was not statistically significant for the latter one. Although not significant, we could find an association between the elevated expression of PD-L2 and the tumor differentiation grade. Increased expression of negative regulator of the anti-tumor immune responses like PD-L2, as a prominent way of tumor escape, can be considered for cancer immunotherapy approaches in CRC patients using blocking monoclonal antibodies.