Laparoscopic versus open surgery for rectal neuroendocrine tumors: a multicenter real-world study.

BACKGROUND: Owing to the lack of evidence-based medical studies with large sample sizes, the surgical approach for the radical resection of rectal neuroendocrine tumors remains controversial. METHODS: We retrospectively collected the medical records of patients with rectal neuroendocrine tumors who underwent radical resection at 17 large tertiary care hospitals in China between January 1, 2010, and April 30, 2022. All patients were divided into laparoscopic and open surgery groups. After propensity score matching to reduce confounders, the postoperative and oncologic outcomes were compared between the groups. RESULTS: We enrolled 174 patients with rectal neuroendocrine tumors who underwent radical surgery. After random matching, 124 patients were included in the comparison (62, laparoscopic surgery group; 62, open surgery group). The laparoscopic surgery group had fewer complications (14.5% vs. 35.5%, P = 0.007) and superior relapse-free survival (P = 0.048). Subgroup analysis revealed that the laparoscopic surgery group had fewer complications (10.9% vs. 34.7%, P = 0.004), shorter postoperative hospital stays (9.56 ± 5.21 days vs. 12.31 ± 8.61 days, P = 0.049) and superior relapse-free survival (P = 0.025) in the rectal neuroendocrine tumors ≤ 4 cm subgroup. CONCLUSIONS: Laparoscopic surgery was associated with improved postoperative outcomes and oncologic prognosis for patients with rectal neuroendocrine tumors ≤ 4 cm; it can serve as a safe and feasible option for radical surgery of rectal neuroendocrine tumors.

Primary Rectal Syphilis Mimicking Lymphoma: A Case Report and Literature Review.

Primary rectal syphilis is a rare disease that can be misdiagnosed as lymphoma or other rectal cancers on sigmoidoscopy or CT. Here, we report a case of primary rectal syphilis mimicking rectal malignancy in a 23-year-old male who presented with a rectal mass and multiple lymphadenopathies. In this case report and literature review, we focused on the CT findings and endoscopic observations of primary rectal syphilis. Infectious diseases, such as rectal syphilis, should be considered in the differential diagnosis of young patients with unusual rectal lesions and disproportionately extensive lymphadenopathies.

Rectal metastasis arising from breast cancer: a case report.

Breast cancer is the most common cancer among women worldwide. Breast cancer often metastasizes to the regional lymph nodes, bone, brain, liver, and lungs, whereas gastrointestinal tract metastases are rare. Herein, we present a rare case of rectal metastasis from breast cancer that occurred during palliative chemotherapy. A 69-year-old female with a history of invasive ductal carcinoma, negative for hormonal receptors and positive for human epidermal growth factor receptor 2 (HER2) receptor, underwent various treatments, including neoadjuvant chemotherapy, breast-conserving surgery, and adjuvant therapy. Eight months postoperatively, the patient experienced axillary lymph node recurrence, requiring palliative chemotherapy. Despite ongoing treatment, metastatic lesions were confirmed in the lungs and pleura. During palliative chemotherapy, the patient developed anal pain, and subsequent examination revealed an infiltrating rectal lesion. Despite histological confirmation of metastatic breast carcinoma and tubular adenoma, a multidisciplinary decision was made regarding palliative chemotherapy over surgical intervention. Eribulin was administered, but due to the patient's inability to tolerate the treatment, she passed away 3 months after rectal lesion diagnosis. Although breast cancer metastasis to the rectum is rare, clinicians should consider the possibility of rectal involvement and perform a digital rectal examination if anal symptoms are present.

Diagnostic Benefits and Surgical Implications of Methods for Tumor Localization in Sigmoid and Rectum Tumors.

(1) Background: In our study, we aimed to determine the accuracy rates of imaging methods for sigmoid, rectosigmoid colon, and rectum cancer. (2) Methods: Patients with tumors located in the rectosigmoid colon, sigmoid colon, and rectum who were operated on were included. Upon admission, we examined the patients' first diagnostic colonoscopies and their preoperative repeat control colonoscopies and computed tomography (CT) report. (3) Results: In this study, 23 patients (57.5%) were male. The overall accuracy rates were 80.0% (32/40) in colonoscopy, 65.0% (26/40) in preoperative CT, and 87.5% (35/40) in retro CT, and the differences among the examination methods were statistically significant (p = 0.049). The sensitivity levels decreased to 50.0% for colonoscopy and preoperative CT and 75.0% for retro CT in rectosigmoid colon tumors. In rectal tumors, the sensitivity levels were 75.0% in colonoscopy, 60.0% in preoperative CT, and 80.0% in retro CT. In two patients, the tumor location was given incorrectly, and postoperative pathological evaluations indicated T3N0 tumors; the initially planned treatment was thus changed to include radiotherapy in addition to chemotherapy in the postoperative period because the tumor was located in the middle rectum. (4) Conclusions: Accuracy in tumor localization in sigmoid, rectosigmoid, and rectum tumors still needs to be improved, which could be accomplished with prospective studies. CT evaluations for cancer localization in this patient group should be re-evaluated by a radiologist.

Symmetry, separation, and stability: Physical properties for effective dosimetric space with a stabilized hyaluronic acid spacer.

BACKGROUND: The proximity of the rectum to the prostate in radiation therapy (RT) for prostate cancer presents a significant dosimetric challenge, leading to high rectal doses and resulting in detrimental side effects. Perirectal tissue spacing reduces rectal dose and gastrointestinal toxicities by mechanically separating these organs. A variety of materials have been explored for use as rectal spacers, most recently, a stabilized hyaluronic acid (HA) gel, which can be formed into deliberate a shape, and retains the definition of that shape, while remaining flexible, unlike polyethylene glycol (PEG) hydrogels. PURPOSE: This study evaluates the dosimetric impact of the spacer, including shape symmetry, the degree of separation at different locations, and the temporal stability of the space. Our goal is to provide physics-informed guidance on the optimal use of this sculptable spacer. METHODS: A secondary analysis was performed on data from a 13-center prospective randomized trial (NCT04189913), involving 136 patients with centrally-reviewed treatment plans conducted on CT/MR simulation scans before and after receiving HA spacer implants. Patients were treated with 60 Gy in 20 fractions to the prostate. For this study, python software was utilized for automated processing of DICOM RTstruct and RTdose files, facilitating detailed analysis of the spacer's impact on anatomical displacement and dosimetric outcomes. Complete dose-volume histograms (DVHs) were reconstructed, and combined into composite population DVHs before and after implant, verified against trial-reported dose points. Patients were divided into similar groups of separation and symmetry, and differences in their composite DVHs were tested for significance. Stability of the spacer was studied by comparing serial MRI images and by computing the distance between contours at four axial planes, at simulation and 3-month follow-up, post RT. RESULTS: The introduction of the HA spacer significantly enhanced rectal sparing, as evidenced by a reduction in the mean rectal integral dose by over 6 Gy. High rates of implant symmetry (>95%) were observed, indicating nearly optimal lateral spacer placement. In superior-inferior coverage, this study like many others, saw the spacing largest at the superior extent but becoming more variable inferiorly at the level of the prostate apex. This allowed study of the apex as a specific area for dosimetric concern. Stability assessments confirmed that the spacer maintained its position and dimensions between the simulation and the 3-month post-RT, implying stable geometry during treatment, with only minimal separation changes observed. Statistical analysis using the Kruskal-Wallis test revealed significant correlations of larger separations at the inferior and apical planes with improved dosimetric outcomes, including rV30Gy. CONCLUSION: The use of a stabilized HA spacer in prostate RT effectively enhances prostate-rectum separation, leading to significant rectal sparing without undesirable dose compromises. This study underscores the role of strategic placement and shape, specifically including > 1 cm separation from the base down to the prostate apex. When combined with the treatment planning techniques used in the trial to create a steep dosimetric gradient across the spacer, these findings elucidate the dosimetric outcomes that can be expected in the clinical implementation of HA spacer. This is particularly relevant in the evolution of hypofractionated treatment regimens for prostate cancer therapy.

Prediction of postoperative residual primary ovarian neoplasm or metastatic lesion close to rectum of serous ovarian carcinoma based on clinical and MR T1-DEI features.

BACKGROUND: The optimal primary debulking surgery outcome of serous ovarian carcinoma (SOC) is greatly affected by primary ovarian neoplasm or metastatic lesion close to the rectum. PURPOSE: To study the risk factors affecting postoperative residual primary ovarian neoplasm or metastatic lesion close to the rectum of SOC. MATERIAL AND METHODS: The clinical and MRI data of 164 patients with SOC eligible from institution A (training and test groups) and 36 patients with SOC eligible from institution B (external validation group) were collected and retrospectively analyzed. The clinical data included age, serum carbohydrate antigen 125 (CA-125), human epididymis protein 4, and neutrophil-to-lymphocyte ratio (NLR). Magnetic resonance imaging (MRI) data included ovarian mass distribution, maximum diameter of ovarian mass, ovarian mass features, degree of rectal invasion of the primary ovarian neoplasm or metastatic lesion, and amount of ascites. A model was established using multivariate logistic regression. RESULTS: By univariate and multivariate logistic regressions, CA-125 (P = 0.024, odds ratio [OR] = 3.798, 95% confidence interval [CI] = 1.24-13.32), NLR (P = 0.037, OR = 3.543, 95% CI = 1.13-12.72), and degree of rectal invasion of the primary ovarian neoplasm or metastatic lesion (P < 0.001, OR = 37.723, 95% CI = 7.46-266.88) were screened as independent predictors. The area under the curve values of the model in the training, test, and external validation groups were 0.860, 0.764, and 0.778, respectively. CONCLUSION: The clinical-radiological model based on T1-weighted dual-echo MRI can be used non-invasively to predict postoperative residual ovarian neoplasm or metastasis close to SOC in the rectum.

Effectiveness and Acceptability of Targeted Text Message Reminders in Colorectal Cancer Screening: Randomized Controlled Trial (M-TICS Study).

BACKGROUND: Mobile phone-based SMS text message reminders have the potential to improve colorectal cancer screening participation rates. OBJECTIVE: This study assessed the effectiveness and acceptability of adding targeted SMS text message reminders to the standard procedure for those who picked up but did not return their screening kit at the pharmacy within 14 days in a colorectal cancer screening program in Catalonia, Spain. METHODS: We performed a randomized control trial among individuals who picked up a fecal immunochemical test (FIT) kit for colorectal cancer screening at the pharmacy but did not return it within 14 days. The intervention group (n=4563) received an SMS text message reminder on the 14th day of kit pick up and the control group (n=4806) received no reminder. A 30-day reminder letter was sent to both groups if necessary. The main primary outcome was the FIT completion rate within 30, 60, and 126 days from FIT kit pick up (intention-to-treat analysis). A telephone survey assessed the acceptability and appropriateness of the intervention. The cost-effectiveness of adding an SMS text message reminder to FIT completion was also performed. RESULTS: The intervention group had higher FIT completion rates than the control group at 30 (64.2% vs 53.7%; P<.001), 60 (78.6% vs 72.0%; P<.001), and 126 (82.6% vs 77.7%; P<.001) days. Participation rates were higher in the intervention arm independent of sex, age, socioeconomic level, and previous screening behavior. A total of 339 (89.2%) interviewees considered it important and useful to receive SMS text message reminders for FIT completion and 355 (93.4%) preferred SMS text messages to postal letters. We observed a reduction of US $2.4 per participant gained in the intervention arm for invitation costs compared to the control arm. CONCLUSIONS: Adding an SMS text message reminder to the standard procedure significantly increased FIT kit return rates and was a cost-effective strategy. SMS text messages also proved to be an acceptable and appropriate communication channel for cancer screening programs. TRIAL REGISTRATION: ClinicalTrials.gov NCT04343950; https://www.clinicaltrials.gov/study/NCT04343950. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.1371/journal.pone.0245806.

An unusual metastatic site of renal cell carcinoma: A case report.

The main metastatic sites of renal cancer are the lungs, bone, liver, and brain. Dissemination of clear cell renal carcinoma to the rectum is very rare, with only a few sporadic cases published in the literature. The clinical presentation is usually dominated by lower gastrointestinal haemorrhage. We report the 5th case in the literature of a rectal metastasis of clear cell renal carcinoma, revealed by a lower gastrointestinal haemorrhage occurring 8 years after the initial nephrectomy.

Comparison of 18F-FDG PET/CT and 18F-DOTATATE PET/CT in the diagnosis of multiple metastases in rectal neuroendocrine neoplasms.

This case report describes a 62-year-old male with a notable medical history, including surgically treated bladder cancer and the suspicion of metastatic disease. He underwent 18F-FDG PET/CT imaging as part of the initial diagnostic workup, which identified several marginally hypodense hepatic lesions. These lesions exhibited metabolic activity that was slightly lower than the surrounding hepatic parenchyma, raising concerns for metastatic involvement. Subsequent 18F-DOTATATE PET/CT imaging significantly expanded the diagnostic perspective by identifying multiple somatostatin receptor (SSTR)-positive lesions, not only in the liver but also in lymph nodes and bones. This marked an important diagnostic advancement over the initial FDG PET/CT findings, showcasing the superior sensitivity of 18F-DOTATATE PET/CT in detecting SSTR-expressing tumors. Pathological evaluation after these imaging studies confirmed the diagnosis of a rectal neuroendocrine tumor (NET) with extensive hepatic metastasis, altering the clinical management and therapeutic approach for the patient. This case underscores the pivotal role of integrating 18F-DOTATATE and FDG PET/CT in the diagnostic and therapeutic management of neuroendocrine tumors, highlighting the complementary nature of these imaging modalities. The findings advocate for the use of 18F-DOTATATE PET/CT in cases where NETs are suspected, particularly for its enhanced sensitivity in detecting SSTR-positive lesions across various sites, thereby facilitating a more comprehensive disease assessment and informed therapeutic planning.

Outcome of Obstructing vs Nonobstructing Colorectal Carcinomas: Comparative Study at Tertiary Care Hospital in Kashmir.

Background: Colorectal cancer (CRC) is the commonly diagnosed malignancy presenting either in obstruction or without obstruction. Bowel obstruction (BO) is usually a complication of advanced cancer, significantly reducing the quality of life. We aimed to study the outcomes of these obstructed colorectal cancers requiring emergency intervention and compare it with nonobstructed cancers. Materials and methods: In our observational comparative study, patients were divided into groups on basis of their presentation and site of lesion: nonobstructing colon group/obstructing colon group nonobstructing rectum group/obstructing rectum group. Results: A total of 232 patients with known modes of presentation between 2015 and 2018 were included; 144 colonic, 88 rectal carcinomas with 71 being completely obstructive ones. Our study showed higher recurrence in obstructive groups with local recurrence being more common. The median interval for recurrence was early in obstructive group (p < 0.001*). The overall 5-year survival rates were better in Nonobstructing colon group, (p = -0.046* in OR vs NOR) (p = -0.031* in OC vs NOC). 5-year disease-free survival rates statistically insignificant (p = 0.203 in NOC and OC groups), (p = 0.307 in NOR and OR groups). Immediate post-op, complications except for SSI, there was no significant difference between the two groups. Our study showed higher proportion of R0 resection in NOC groups as compared with obstructive groups (p = 0.021* in in OC vs NOC and p = 0.037* in OR vs NOR) with better lymph node retrieval in NOC groups. Conclusion: On comparing outcome of patients who had completed multi-modal therapy in both groups, there was significantly better outcome for patients who have presented without obstruction. How to cite this article: Ul Haq MF, Bhat GA, Wani MA, et al. Outcome of Obstructing vs Nonobstructing Colorectal Carcinomas: Comparative Study at Tertiary Care Hospital in Kashmir. Euroasian J Hepato-Gastroenterol 2024;14(1):75-80.

Colorectal endometriosis - a challenging, often overlooked cause of colorectal pathology: a clinicopathological review of 114 cases.

The colon is the most common site for endometriosis outside the genital tract. It has a varied presentation and can mimic numerous other conditions, both clinically and pathologically. We investigated the clinicopathological features of a series of colorectal endometriosis with a particular emphasis on the features seen in cases with colonic mucosal involvement. A total of 114 consecutive cases of colorectal endometriosis were reviewed. Forty-eight percent did not have a prior diagnosis of endometriosis and in 34 patients (30%) the endometriosis was determined as the cause for the presentation. Mucosal involvement was present in 31 specimens. Features of chronic colitis were seen in the adjacent mucosa in 90% of cases whilst there were glandular changes mimicking adenocarcinoma in two cases (1.8%). Fifty percent of cases with mucosal involvement also showed glands with a hybrid intestinal-endometrial phenotype by morphology and/or by immunohistochemistry. Endometriosis is an important mimic of other conditions.

The role of endoscopic ultrasonography for diagnosis of residual rectal neuroendocrine tumor.

BACKGROUND: Endoscopic ultrasonography (EUS) is useful for assessing the depth and regional lymph node involvement in rectal neuroendocrine tumors (NETs). However, evidence regarding the effectiveness of EUS in identifying residual lesions in patients with incompletely resected NET is limited. We aimed to evaluate the efficacy of EUS in identifying residual rectal NETs and the clinical outcomes of salvage endoscopic treatment. METHODS: We retrospectively reviewed the records of patients who were transferred to Chosun University Hospital and received salvage treatment for incompletely resected rectal NETs between January 2012 and October 2021. RESULTS: This study included 68 incompletely resected rectal NET, of which 59 were margin-positive and 9 were margin-indeterminate. EUS detection (odds ratio (OR), 8.44; 95% confidence interval (CI), 1.18-41.35) and visual detection (OR, 7.00; 95% CI, 1.50-47.48) were associated with residual lesion in patients with incompletely resected NET. EUS detection of residual lesions showed a sensitivity of 94%, specificity of 71%, positive predictive value of 88%, negative predictive value of 83%, and accuracy of 87%. All patients underwent salvage treatment with band-ligation endoscopic mucosal resection (58.8%) and endoscopic submucosal dissection (41.2%). Residual NETs were diagnosed in 47 of 68 patients (69.1%), and no recurrence was noted during the follow-up period of 51.8 ± 22.9 months. CONCLUSIONS: EUS is a more sensitive method than visual detection for evaluating residual rectal NETs. Salvage endoscopic treatment for incompletely resected NETs is safe and effective.

Emergency surgery for acute rectal bleeding in a newly diagnosed case of fulminant ulcerative colitis.

INTRODUCTION: The incidence of ulcerative colitis is rising among Asian population. Massive bleeding per rectum is an uncommon, but serious, complication of UC accounting for 0.1-1.4 % of admissions. CASE PRESENTATION: A 22-year-old male, reported persistent abdominal pain, bloody diarrhea, and intermittent vomiting for one week. Physical examination revealed signs of dehydration and pallor. Laboratory tests showed elevated inflammatory markers. CT and colonoscopy confirmed ulcerative colitis, refractory to corticosteroids, leading to a subtotal colectomy followed by Ileal Pouch-Anal Anastomosis. The patient was symptom free at a 24-month follow-up. DISCUSSION: Bleeding that occurs during the initial stages of the disease or in cases where the diagnosis of ulcerative colitis hasn't been confirmed makes it challenging for patients to accept the need for extensive surgery and the creation of a stoma. Conservative procedures are advised in such settings. CONCLUSION: Acute severe bleeding in ulcerative colitis is rare but demands a multidisciplinary approach for timely diagnosis and treatment. In resource and expertise limited situation, where patients are noncompliant to regular follow-ups surgical treatment can still be intervention of choice for these cases.

Retrospective Analysis of Rectal Endoscopic Submucosal Dissection at Ordensklinikum Linz and Kepler Universitätsklinikum Linz.

Background and study aim: Endoscopic submucosal dissection is a minimally invasive endoscopic procedure for the removal of neoplastic benign and early malignant lesions in the gastrointestinal tract. In this study, we analyse the success and safety of rectal ESD at Linz hospitals, focusing on a specific endoscopist. Additionally, we examine whether there is a learning curve regarding success parameters. Methods: This retrospective study included all 102 patients who underwent endoscopic submucosal dissection of the rectum by a defined endoscopist at Ordensklinikum Hospital and Kepler University Hospital between December 2010 and May 2021. With the collected data, a descriptive statistic was carried out and regression analyses were performed. Results: The en bloc resection rate was 78.4% and the rate of lesions removed in healthy tissue was 55.6%. The average procedure time was 179 min and the complication rate was 7.8%. In total, 26.4% of cases showed carcinoma; in 25.9% of these cases, an oncologically curative resection was achieved with ESD. Follow-up data were available for 61.1% of cases, with recurrence being diagnosed in 3.6% of cases. A learning curve was observed regarding the rate of lesions removed in healthy tissue and the procedure time, but not regarding the en bloc resection rate. Conclusions: Endoscopic submucosal dissection is a safe method for the removal of large rectal adenomas and early carcinomas. The en bloc resection rate of the analysed procedures is within the range of comparable European studies. The rate of lesions removed in healthy tissue is below the R0 resection rate of the comparative literature; however, a learning curve could be observed in this parameter.

Influence of the COVID-19 Pandemic on Patients with Rectal Cancer.

Objectives: The COVID-19 pandemic and its associated restrictions have resulted in delayed diagnoses across various tumor entities, including rectal cancer. Our hypothesis was based on the expectation of a reduced number of primary operations due to higher tumor stages compared to the control group. Methods: In a single-center retrospective study conducted from 1 March 2018 to 1 March 2022, we analyzed 120 patients with an initial diagnosis of rectal cancer. Among them, 65 patients were part of the control group (pre-COVID-19), while 55 patients were included in the study group (during the COVID-19 pandemic). We compared tumor stages, treatment methods, and complications, presenting data as absolute numbers or mean values. Results: Fewer primary tumor resections during the COVID-19 pandemic (p = 0.010), as well as a significantly lower overall number of tumor resections (p = 0.025) were seen compared to the control group. Twenty percent of patients in the COVID-19 group received their diagnosis during lockdown periods. These patients presented significantly higher tumor stages (T4b: 27.3% vs. 6.2%, p = 0.025) compared to the control group prior to the pandemic. In addition, more patients with angiolymphatic invasion (ALI) were identified in the COVID-19 group following neoadjuvant treatment compared to the control group (p = 0.027). No differences were noted between the groups regarding complications, stoma placement, or conversion rates. Conclusions: The COVID-19 pandemic, particularly during lockdown, appears to have contributed to delayed diagnoses, resulting in higher tumor stages and a decreased number of surgeries. The quality of rectal cancer treatment can be maintained under pandemic conditions.

Personalized Decisional Algorithms for Soft Tissue Defect Reconstruction after Abdominoperineal Resection for Low-Lying Rectal Cancers.

BACKGROUND: Abdominoperineal resection (APR)-the standard surgical procedure for low-lying rectal cancer (LRC)-leads to significant perineal defects, posing considerable reconstruction challenges that, in selected cases, necessitate the use of plastic surgery techniques (flaps). PURPOSE: To develop valuable decision algorithms for choosing the appropriate surgical plan for the reconstruction of perineal defects. METHODS: Our study included 245 LRC cases treated using APR. Guided by the few available publications in the field, we have designed several personalized decisional algorithms for managing perineal defects considering the following factors: preoperative radiotherapy, intraoperative position, surgical technique, perineal defect volume, and quality of tissues and perforators. The algorithms have been improved continuously during the entire period of our study based on the immediate and remote outcomes. RESULTS: In 239 patients following APR, the direct closing procedure was performed versus 6 cases in which we used various types of flaps for perineal reconstruction. Perineal incisional hernia occurred in 12 patients (5.02%) with direct perineal wound closure versus in none of those reconstructed using flaps. CONCLUSION: The reduced rate of postoperative complications suggests the efficiency of the proposed decisional algorithms; however, more extended studies are required to categorize them as evidence-based management guide tools.

The Association of Mismatch Repair Status with Microscopically Positive (R1) Margins in Stage III Colorectal Cancer: A Retrospective Cohort Study.

BACKGROUND: There is mounting evidence that microscopically positive (R1) margins in patients with colorectal cancer (CRC) may represent a surrogate for aggressive cancer biology rather than technical failure during surgery. However, whether detectable biological differences exist between CRC with R0 and R1 margins is unknown. We sought to investigate whether mismatch repair (MMR) status differs between Stage III CRC with R0 or R1 margins. METHODS: Patients treated for Stage III CRC from January 1, 2016 to December 31, 2019 were identified by using the Danish Colorectal Cancer Group database. Patients were stratified according to MMR status (proficient [pMMR] vs. deficient [dMMR]) and margin status. Outcomes of interest included the R1 rate according to MMR and overall survival. RESULTS: A total of 3636 patients were included, of whom 473 (13.0%) had dMMR colorectal cancers. Patients with dMMR cancers were more likely to be elderly, female, and have right-sided cancers. R1 margins were significantly more common in patients with dMMR cancers (20.5% vs. 15.2%, p < 0.001), with the greatest difference seen in the rate of R1 margins related to the primary tumour (8.9% vs. 4.7%) rather than to lymph node metastases (11.6% vs. 10.5%). This association was seen in both right- and left-sided cancers. On multivariable analyses, R1 margins, but not MMR status, were associated with poorer survival, alongside age, pN stage, perineural invasion, and extramural venous invasion. CONCLUSIONS: In patients with Stage III CRC, dMMR status is associated with increased risks of R1 margins following potentially curative surgery, supporting the use of neoadjuvant immunotherapy in this patient group.

En-bloc excision of sacral squamous cell carcinoma with immediate reconstruction.

Sacral squamous cell carcinoma is an uncommon condition that may arise in scars following burns or in chronic wounds, such as an untreated pilonidal cyst. The aim of the present technical note is to describe a surgical technique aimed at minimizing local recurrence rates by en-bloc resection as well as providing immediate plastic reconstruction: 1. right-sided extended vertical rectus abdominis myo-cutaneous (VRAM) flap; 2. abdomino-perineal excision of the rectum with end colostomy; 3. en-bloc excision of the mass inclusive of gluteus maximus muscles and distal sacrectomy; 4. sacrectomy defect covered with VRAM flap; 5. bilateral gluteal defects covered with single-layer dermal substitute of bovine collagen and elastin hydrolysate followed by immediate split-thickness skin grafting from bilateral thigh donor sites, and negative pressure wound therapy dressings. This approach resulted in a favorable outcome at 2-year follow-up in a male patient presenting with a large locally advanced sacral squamous cell carcinoma involving the external anal sphincter muscle.

Rectal volume is correlated with interfractional positional shifts of the prostate gland in dogs receiving radiation therapy.

Variability in prostate gland positioning during RT for prostate tumors is a recognized challenge in both human and veterinary oncology. This retrospective study investigates the interfractional variability in prostate gland positioning in relation to rectal and bladder volumes in dogs undergoing radiation therapy (RT) for prostate tumors. The study tracked 10 dogs undergoing five RT sessions from February 2016 to November 2021, delivering a total of 25 Gy each. Each dog underwent CT scans for treatment simulation, and cone-beam CT (CBCT) images were acquired before each RT. The focus was to analyze the positional shifts of the prostate gland concerning the volumes of the rectum and urinary bladder. The pelvic bones were used as the point of reference. The rectal and bladder volumes were measured before each RT, and shifts in the prostate gland position were calculated by comparing coordinates from planning CT and treatment session images. Findings revealed significant correlations between prostate positional shifts in the dorsal-ventral (repeated measures correlation coefficient of -0.58 [range 00.75-00.33]; P < .001) and cranial-caudal directions (repeated measures correlation coefficient [95%CI] 0.56 [range 0.31-0.74]; P < .001) and rectal volume, while no significant relationship was observed with bladder volume. Shifts in the lateral direction were not correlated with either organ's volume. This study highlights the importance of considering rectal volume in canine prostate tumor RT to minimize positional uncertainties. Maintaining consistent rectal volume may enhance the precision of prostate targeting, potentially influencing the safety of RT.