Sphincter Involvement Research Articles

Case report: Perineal swelling: A rare case of scar endometriosis.

We report a rare case of episiotomy site scar endometriosis manifested as painful perineal swelling near the anus for 2 years affecting daily routine activity, especially during menses. A 33-year-old female, para 2 with both vaginal deliveries with last child birth 8 years back. A 2.5 × 3 cm firm, tender nodule was present on the posterior vulva at the right mediolateral episiotomy site. Trans-perineal and trans-anal ultrasound scan was done, anal sphincter involvement was ruled out and the nodule was excised with free margins. histopathology confirmed the diagnosis of scar endometriosis. The key takeaway from this case is endometriosis can present after 8 years of vaginal delivery. The timely diagnosis and treatment is necessary as delay may cause anal sphincter involvement or malignant transformation.

Imaging and Metabolic Diagnostic Methods in the Stage Assessment of Rectal Cancer.

Rectal cancer (RC) is a prevalent malignancy with significant morbidity and mortality rates. The accurate staging of RC is crucial for optimal treatment planning and patient outcomes. This review aims to summarize the current literature on imaging and metabolic diagnostic methods used in the stage assessment of RC. Various imaging modalities play a pivotal role in the initial evaluation and staging of RC. These include magnetic resonance imaging (MRI), computed tomography (CT), and endorectal ultrasound (ERUS). MRI has emerged as the gold standard for local staging due to its superior soft tissue resolution and ability to assess tumor invasion depth, lymph node involvement, and the presence of extramural vascular invasion. CT imaging provides valuable information about distant metastases and helps determine the feasibility of surgical resection. ERUS aids in assessing tumor depth, perirectal lymph nodes, and sphincter involvement. Understanding the strengths and limitations of each diagnostic modality is essential for accurate staging and treatment decisions in RC. Furthermore, the integration of multiple imaging and metabolic methods, such as PET/CT or PET/MRI, can enhance diagnostic accuracy and provide valuable prognostic information. Thus, a literature review was conducted to investigate and assess the effectiveness and accuracy of diagnostic methods, both imaging and metabolic, in the stage assessment of RC.

Comparison of outcomes of abdominoperineal resection vs low anterior resection in very-low rectal cancer

BackgroundThe management of very-low rectal cancer is one of the most challenging issues faced by general and colorectal surgeons. Many feel compelled to pursue abdominoperineal resection (APR) over low anterior resection (LAR) to optimize oncologic outcomes. This study aimed to determine differences in long-term oncologic outcomes between patients undergoing APR or LAR for very-low rectal cancer. MethodsThe United States Rectal Cancer Consortium (2010–2016) was queried for adults who underwent either APR or LAR for stage I-III rectal cancers < 5 cm from anorectal junction and met inclusion criteria. The primary outcome was disease-free survival. Secondary outcomes included overall survival, length of stay, complications, recurrence location, and perioperative factors. ResultsA total of 431 patients with very-low rectal cancer who underwent APR or LAR were identified; 154 (35.7%) underwent APR. The overall recurrence rate was 19.6%. The median follow-up was 42.5 months. An analysis adjusted for demographics and pathologic stage observed no difference in disease-free survival between operative types (APR-hazard ratio [HR] = 0.90, 95% CI: 0.53–1.52, P = .70). Secondary outcomes demonstrated no significant difference between operation types, including overall survival (HR = 1.29, 95% CI: 0.71–2.32, P = .39), complications (OR = 1.53, 95% CI: 0.94–2.50, P = .12), or length of stay (estimate: 0.04, SE = 0.25, P = .54). ConclusionWe observed no significant difference in disease-free survival or overall survival between patients undergoing APR or LAR for very-low rectal cancer. This analysis supports the treatment of very-low rectal cancer, without sphincter involvement, by either APR or LAR.

Pelvic Diameter is not Associated with Positive Circumferential Resection Margin in Rectal Cancer: Retrospective Analysis of 78 Cases

Abstract Objective To identify if there is an association between pelvic entry and pelvic outlet diameters with increased positive circumferential resection margin (CRM) in rectal cancer. Introduction Positive CRM in rectal cancer is a major predictor for local and distant recurrence. Pelvic diameters may be related to the difficulty of dissection, as well as intrinsic tumor characteristics such as tumor size, location, distance from the anal margin, and T stage, which may compromise the integrity of the mesorectum and circumferential margin involvement. Methods A retrospective review of the patient's medical records who underwent surgical resection of rectal adenocarcinoma from January 2012 to June 2022 was performed. The patient's preoperative staging, operative characteristics, and histopathologic outcomes were gathered from the medical records. Preoperative MRI scanning was done in all patients. MRI pelvimetry was done by two observers. CRM involvement was recorded as stated in the pathology report. Pelvimetry variables were dichotomized according to their mean values for correlation analysis. The odds ratio (OR) was calculated from a binary logistics regression model to assess the relation between the positive CRM and the independent variables. Results A total of 78 patients were included in this study. A positive CRM was reported in 10 patients (12.8%). BMI &gt;27.4 + 6.6 (p = 0.02), positive extramural vascular invasion (p = 0.027), positive CRM by MRI scanning (p = 0.004), and anal sphincter involvement (p = 0.03) were associated with positive CRM. Pelvimetry values were not associated with a positive CRM. Conclusion No association was found between the pelvic diameters measured by MRI pelvimetry with a positive CRM.

Low Rectal Cancers at Initial Staging MRI.

Low rectal cancers, which are associated with increased risk of local recurrent disease and poorer prognosis, have unique anatomic considerations and issues for staging and treatment that do not apply to mid and high rectal cancers. Although tumor histology help drive the staging and treatment of all rectal cancers, it is of particular importance in low rectal cancers, which may involve the anal canal, to help establish whether a low rectal mass should be staged and treated as a rectal cancer (ie, adenocarcinoma) or an anal cancer (ie, squamous cell carcinoma). Optimal staging and treatment of rectal cancer are contingent on tumor location and local extent, which help guide management decisions including neoadjuvant therapy and curative surgical treatment strategies. Tumor location in the low rectum and local involvement of the anal canal, sphincter, and pelvic floor help determine whether a patient can undergo sphincter-preserving resection such as a low anterior resection versus abdominoperineal resection to achieve negative surgical margins. Issues exist related to the anatomy and patterns of disease spread that are unique to the low rectum and include how to determine and stage anal sphincter involvement, mesorectal fascia status at the pelvic floor, and nodal status of extramesorectal nodes such as the external iliac and inguinal lymph nodes. For these reasons, it is imperative that radiologists who interpret rectal cancer staging MRI examinations feel comfortable with the unique anatomy of the low rectum and anal canal, nuances of low rectal cancer local disease spread, and treatment paradigms for low rectal cancer. ©RSNA, 2023 Online supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center. See the invited commentary by Gollub in this issue.

THeragnostic utilities for neoplastic DisEases of the rectum by MRI guided radiotherapy (THUNDER 2) phase II trial: interim safety analysis

BackgroundThe THUNDER-2 phase II single institutional trial investigates the benefits of MRI-guided radiotherapy (MRIgRT) in treating locally advanced rectal cancer (LARC). This study focuses on evaluating the impact of escalating radiation therapy dose in non-responder patients using the Early Tumour Regression Index (ERI) for predicting complete response (CR). The trial’s primary endpoint is to increase the CR rate in non-responders by 10% and assess the feasibility of the delta radiomics-based MRIgRT predictive model. This interim analysis assesses the feasibility and safety of the proposed MRIgRT dose escalation strategy in terms of acute toxicity (gastrointestinal, genitourinary and haematological) and treatment adherence.MethodsStage cT2-3, N0-2, or cT4 patients with anal sphincter involvement, N0-2a, M0, but without high-risk features were enrolled. MRIgRT treatment consisted of a standard dose of 55 Gy to the Gross Tumor Volume (GTV) and mesorectum, and 45 Gy to the mesorectum and drainage nodes in 25 fractions with concomitant chemotherapy. 0.35 T MRI was used for simulation imaging and daily alignment. ERI was calculated at the 10th fraction. Non-responders with an ERI above 13.1 received intensified dose escalation from the 11th fraction, resulting in a total dose of 60.1 Gy. Acute toxicity was assessed using the CTCAE v.5 scale.ResultsFrom March 2021 to November 2022, 33 out of the total number of 63 patients to be enrolled (52.4%) were included, with one withdrawal unrelated to treatment. Sixteen patients (50%) underwent dose escalation. Treatment was well tolerated, with only one patient (3.1%) in the standard treatment group experiencing acute Grade 3 diarrhea, proctitis, and cystitis. No significant differences in toxicity were observed between the two groups (p = 0.5463).ConclusionsMRIgRT treatment with dose escalation up to 60.1 Gy is well tolerated in LARC patients predicted as non-responders by ERI, confirming the feasibility and safety of this approach. The THUNDER-2 trial’s primary and secondary endpoints will be fully analyzed when all planned patients will be enrolled.

Plasma GDNF levels in spinal dysraphism and its relation with neurological impairment in children: A point of care study

GDNF plays a crucial role in the stimulation of recovery, neuroplasticity and synaptic reorganization after spinal cord injury providing neuroprotection and neuroregeneration. Plasma GDNF levels are upregulated in cases of spina bifida owing to the intrauterine damage of the exposed spinal cord. Our aim was to compare the plasma GDNF levels in patients of spina bifida with non-spina bifida cases and assess the correlation with neurological impairment at one year of follow up. Single centre prospective analysis of cases of spina bifida from 2020 to 2022at presentation and after one year of follow up post-surgery. Cases with hernia and hydrocele without any other disorders were recruited into the control group. Plasma GDNF levels were assessed with immunoassay kits and compared with neurological involvement. 85 cases were included in the study. GDNF levels were elevated in cases compared to controls (mean 6.62 vs 1.76) with significant p value (<0.01). Same was observed for open and closed defects (mean 7.63 vs 4.86: p<0.01). At follow up of 52 cases post-surgery cases with neurogenic bladder with abnormal urodynamic studies, sphincter involvement and motor impairment had significantly elevated baseline levels of GDNF compared with those who did not have this neurological impairment (p<0.01). The neurotrophic factor up-regulation can reflect an endogenous attempt at neuroprotection against the biochemical and molecular cascades triggered by the spinal cord damage. This upregulation can be represented as important biochemical markers of severe spinal cord damage and can be associated with severity of spine injury in MMC patients. Our results are in keeping with these findings, that, there were increased levels of plasma GDNF levels in cases of spinal dysraphism compared to control population. Also, the type of lesion reflecting the severity whether a closed or an open dysraphism, showed significant difference in levels between them suggesting, yet again, more damage in open defect as expected. The levels were higher with involvement of bladder, sphincter and lower limb power. There is significant elevation of plasma GDNF levels in cases of spina bifida and this elevation is proportional to the degree of spinal damage and hence the neurological impairment. GDNF levels are a good predictor for assessing the severity of the lesion and thus the outcome in these cases. Additional prospective and long-term studies with a larger cohort are needed for a better understanding of neurotrophin pattern modulation in MMC.

Outcomes of Watch and Wait Following Total Neoadjuvant Therapy for Rectal Cancer

To evaluate the outcomes of patients with locally advanced rectal cancer who achieved a clinical complete response (cCR) after total neoadjuvant therapy and enrolled in a prospective watch and wait (WW) database. Consecutive patients with locally advanced rectal cancer who achieved cCR following total neoadjuvant therapy (long-course chemoradiotherapy plus systemic chemotherapy) and were enrolled in our institutional WW surveillance protocol from 2014 through 2022 with the intention of organ preservation. Patients with lack of follow up according to our institutional protocol were excluded. Primary outcomes included local tumor regrowth and distant metastatic disease recurrence. Thirty-three consecutive patients (48% male; median age 61 [33-77] years) with the diagnosis of locally advanced rectal adenocarcinoma were managed by a multidisciplinary team. All patients had Eastern Cooperative Oncology Group Performance Status score of 0 or 1 at time of rectal cancer diagnosis. Location of tumor included upper rectum (18%), middle rectum (40%), and lower rectum (42%). On initial staging magnetic resonance imaging, 4 (12%) patients had evidence of extramural venous invasion, 6 (18%) had a threatened mesorectal margin, and 4 (12%) had anal sphincter or levator ani tumor involvement. A majority (61%) received chemotherapy followed by long-course chemoradiotherapy. Only one patient had an unplanned break during radiotherapy. Local tumor regrowth was diagnosed in 4 (12%) patients and all underwent successful salvage surgery without additional local failures at a median follow-up of 19 [12-48] months. Two of these four patients remain disease-free at a median follow-up time of 12.5 months. Mean time to local tumor regrowth as first site of cancer recurrence was 33.5 [18-46] months. Distant metastatic disease as the first site of recurrence occurred two patients (6%). Mean time to distant metastatic disease as first site of recurrence was 27 months. Only one mortality occurred in the entire group at a median follow-up of 49 [8-102] months. Organ preservation after total neoadjuvant therapy for locally advanced rectal cancer yields excellent outcomes with low local and distant relapse rates. Structured surveillance protocols and multidisciplinary care are essential for success.

Pearls and pitfalls of structured staging and reporting of rectal cancer on MRI: an international multireader study.

To investigate uniformity and pitfalls in structured radiological staging of rectal cancer. Twenty-one radiologists (12 countries) staged 75 rectal cancers on MRI using a structured reporting template. Interobserver agreement (IOA) was calculated as the percentage agreement between readers (categorical variables) and Krippendorff's α (continuous variables). Agreement with an expert consensus served as a surrogate standard of reference to estimate diagnostic accuracy. Polychoric correlation coefficients were used to assess correlations between diagnostic confidence and accuracy (=agreement with expert consensus). Uniformity to diagnose high-risk (≥cT3 ab) versus low-risk (≤cT3 cd) cT-stage, cN0 versus cN+, lateral nodes and tumour deposits, MRF and sphincter involvement, and solid versus mucinous tumours was high with IOA > 80% in the majority of cases (and >80% agreement with expert consensus). Results for assessing extramural vascular invasion, cT-stage (cT1-2/cT3/cT4a/cT4b), cN-stage (cN0/N1/N2), relation to the peritoneal reflection, extent of sphincter involvement (internal/intersphincteric/external) and morphology (solid/annular/semi-annular) were considerably poorer. IOA was high (α = 0.72-0.84) for tumour height/length and extramural invasion depth, but low for tumour-MRF distance and number of (suspicious) nodes (α = 0.05-0.55). There was a significant positive correlation between diagnostic confidence and accuracy (=agreement with expert consensus) (p < 0.001-p = 0.003). - Several staging items lacked sufficient reproducibility.- Results for cT- and N-staging g improved when using a dichotomized stratification.- Considering the significant correlation between diagnostic confidence and accuracy, a confidence level may be incorporated into structured reporting for specific items with low reproducibility. Although structured reporting aims to achieve uniformity in reporting, several items lack sufficient reproducibility and might benefit from dichotomized assessment and incorporating confidence levels.

Intradural extramedullary tumors. Retrospective cohort study assessing prognostic factors for functional outcome in adult patients

ObjectiveThe purpose of this study is to analyze a series of patients with intradural extramedullary tumors (IDEM) and assess factors that may modify or determine the final long term outcome and management. Materials and methodsSingle Center, retrospective study of a series of surgical patients with IDEM lesions from our Institution operated between 2010 and 2021. Patients with less than 6 months of follow up were excluded. Several preoperative demographics, clinical, imaging and surgical features, as well as histopathology, recurrence and adjuvancy were assessed. Patients’ final clinical outcome was categorized using the McCormick scale. ResultsA total of 203 patients with a mean follow-up of 30.50 months (range 6–130) were included. 57.64% of the analyzed population was female and the mean age was 50.51 years.The most frequent location of the tumors was dorsal (34.98%) followed by the lumbar region (32.02%). Total resection was achieved in 84.24% of cases, and the most frequent histopathology was Schwannoma (36.45%), followed by Meningioma (30.05%). Pain was the most usual initial symptom (63.05%).In our analysis, functional outcome after surgery was associated with statistical significance with preoperative McCormick grade, tumor type, EOR and postoperative complications such as hematoma and sphincter involvement. ConclusionThe management of these lesions depends on many factors. It is worthy of mention that clinical presentation, EOR, histopathology and postoperative complications have shown significant prognostic value for the final outcome. Early treatment with the intention of achieving GTR when possible, using carefully tailored approaches, should be considered before the onset of significant symptoms.

Rerouting as a Sphincter Saving Procedure for Management of Horseshoe Perianal Fistula

Abstract Background Horseshoe fistula remains a complex and challenging clinical entity due to the configuration, depth, degree of sphincter involvement and confusing anatomy of the fistula. Lack of recognition, high rates of recurrence after insufficient treatment and incontinence are the dominant issues surrounding the management of the disease. We provide a new technique, which is staged fistulotomy with rerouting of transsphincteric track into intersphincteric position and the newly positioned intersphincteric fistula is then dealt with at a later date when the wound related to the external sphincter is soundly healed, so we achieve the gold standard lay open of the fistula in addition to minimal sphincter sacrificing aiming to the least recurrence rate and avoiding functional complications as much as possible. Aim The aim was to describe the surgical technique that we use for the treatment of horseshoe perianal fistula and to study its effect on recurrence and continence. Patients and Methods A prospective study in which thirty patients to be operated upon was recruited from Ain Shams University Hospital &amp; Dar Elshefa Hospital. Staged fistulotomy with rerouting of transsphincteric track of the fistula into intersphincteric position was done. The newly positioned intersphincteric fistula is then dealt with at a later date when the wound related to the external sphincter is soundly healed. Results 23 cases (76%) out of 30 cases to be operated upon underwent all stages of the procedure. As regard Patients underwent all stages of the procedure 20 cases (87%) developed no degree of incontinence 3 cases (13%) developed degree of incontinence (wexner score 2)(gas leak once a week). There were no cases of recurrence. Conclusion Staged fistulotomy for horseshoe fistula with rerouting of transsphincteric track into intersphincteric position was associated with no recurrence and accepted functional complications.

The role of magnetic resonance tumour regression grade in the prediction of regression and survival of rectal adenocarcinoma after long-course chemoradiotherapy: a cohort study.

Between 2011 and 2016, patients with rectal cancer who underwent LCCRT and had post-LCCRT MRI were included in the study. Both mrTRG and pTRG were dichotomised into good responders (mrTRG 1-3 and pTRG 0-1) and poor responders (mrTRG 4-5 and pTRG 2-3). Correlation between mrTRG and pTRG was assessed with Cohen κ analysis. Survival analysis was performed with Kaplan-Meier test and Cox proportional hazard models. There were 59 patients included in this study. There were significant reductions in anal sphincter and circumferential resection margin involvement in post-LCCRT MRI. Fair agreement was found between mrTRG and pTRG (κ=0.345). Sensitivity, specificity and accuracy of mrTRG 1-3 to predict good pathological response were 100%, 46.3% and 62.7%, respectively. On survival analysis, mrTRG 1-3 was not associated with improved overall survival and recurrence-free survival. While there is fair agreement in correlation between mrTRG and pTRG, MRI remains an objective, noninvasive assessment of tumour response. Further studies are required to improve the ability of mrTRG to predict good responders to LCCRT and evaluate its role as a prognostic marker for survival.

Intradural extramedullary tumors. Retrospective cohort study assessing prognostic factors for functional outcome in adult patients

ObjectiveThe purpose of this study is to analyze a series of patients with intradural extramedullary tumors (IDEM) and assess factors that may modify or determine the final long term outcome and management. Materials and methodsSingle Center, retrospective study of a series of surgical patients with IDEM lesions from our Institution operated between 2010 and 2021. Patients with less than 6 months of follow up were excluded. Several preoperative demographics, clinical, imaging and surgical features, as well as histopathology, recurrence and adjuvancy were assessed. Patients’ final clinical outcome was categorized using the McCormick scale. ResultsA total of 203 patients with a mean follow-up of 30.50 months (range 6–130) were included. 57.64% of the analyzed population was female and the mean age was 50.51 years.The most frequent location of the tumors was dorsal (34.98%) followed by the lumbar region (32.02%). Total resection was achieved in 84.24% of cases, and the most frequent histopathology was Schwannoma (36.45%), followed by Meningioma (30.05%). Pain was the most usual initial symptom (63.05%).In our analysis, functional outcome after surgery was associated with statistical significance with preoperative McCormick grade, tumor type, EOR and postoperative complications such as hematoma and sphincter involvement. ConclusionThe management of these lesions depends on many factors. It is worthy of mention that clinical presentation, EOR, histopathology and postoperative complications have shown significant prognostic value for the final outcome. Early treatment with the intention of achieving GTR when possible, using carefully tailored approaches, should be considered before the onset of significant symptoms.

Intra- and interobserver agreement of rectal cancer staging with MRI.

Reliable preoperative staging of rectal cancers is crucial for treatment decision making. To assess the intra- and inter-observer agreement of rectal cancer staging, including the sub-categories, with magnetic resonance imaging (MRI). The study includes 85 patients (35.3% women; mean age = 62.2 ± 11.2 years) who underwent MRI for rectal cancer staging between August 2020 and April 2021. All the stored images were evaluated independently by two radiologists with 10-15 years of experience. For intra-observer agreement, the evaluations were done two months apart. Analyses were made using kappa, prevalence and bias-adjusted kappa (PABAK), and intraclass correlation coefficient (ICC), where appropriate. There was a substantial inter-observer agreement for tumor localization (kappa = 0.665, PABAK = 0.682), mesorectal fascia invasion (kappa = 0.663, PABAK = 0.822), internal and external sphincter involvement (kappa 0.804 and 0.751, PABAK 0.859 and 0.929, respectively), and moderate to substantial agreement for M-staging (kappa = 0.451, PABAK = 0.742) and extramural vascular invasion (kappa = 0.569, PABAK = 0.741). There was also a good inter-observer agreement for T staging and N staging (ICC = 0.862, 95% confidence interval [CI] = 0.788-0.911; and ICC = 0.841, 95% CI = 0.595-0.922, respectively). As expected, intra-observer agreement was better than inter-observer agreement. Intra- and inter-observer agreement for MRI staging of rectal cancers using the structured reporting template is good.

Clinical presentation of perineal endometriosis and prognostic nomogram after surgical resection

BackgroundThis retrospective study evaluated the clinical features of perineal endometriosis (PEM) and established a prognostic nomogram for recurrence probability in patients treated with surgical resection.MethodsThis study enrolled 130 PEM patients who had received surgical treatment in Peking Union Medical College Hospital (PUMCH) between January 1992 and September 2020. We collected their clinical features and conducted outpatient or telephone follow-up. The predictive nomogram was constructed based on 104 patients who had completed follow-up by July 2021. The Cox proportional hazards regression model was used to evaluate the prognostic effects of multiple clinical parameters on recurrence. The Index of concordance (C-index) and calibration curves were used to access the discrimination ability and predictive accuracy of the nomogram respectively, and the results were further validated via bootstrap resampling. Calculating the area under the curve (AUC) via risk scores of patients aimed to further access the predictive power of the model. In addition, the survival curve was depicted using Kaplan–Meier plot and compared by log-rank method.ResultsMost PEM patients had been symptomatic for 24–48 months before the lesion resection. With a median 99.00 (interquartile range: 47.25–137.50) months of postoperative observation, there were 16 (15.1%) out of 104 cases who finished follow-up reported symptomatic recurrence. On multivariate analysis of derivation cohort, multiple lesions, microscopically positive margin (mPM) and anal sphincter involvement (ASI) were selected into the nomogram. The C-index of the nomogram for predicting recurrence was 0.84 (95% CI 0.77–0.91). The calibration curve for probability of recurrence for 36, 60 and 120 months showed great agreement between prediction by nomogram and actual observation. Furthermore, the AUCs of risk score for 36, 60 and 120 months were 0.89, 0.87 and 0.82 respectively.ConclusionsPEM is a rare kind of endometriosis and surgery is the primary treatment. Multiple lesions and ASI are independent risk factors for postoperative recurrence, and wide resection with more peripheral tissue could be preferred. The proposed nomogram resulted in effective prognostic prediction for PEM patients receiving surgical excision. In addition, this predictive nomogram needs external data sets to further validate its prognostic accuracy in the future.

Dentate line invasion as a predictive factor of poor distant relapse-free survival in locally advanced lower rectal cancer with anal sphincter involvement

BackgroundWhile an important surgical landmark of the dentate line has been established for locally advanced lower rectal cancer (LALRC), the prognostic significance of dentate line invasion (DLI) has not been well defined. This study aimed to explore the impact of DLI on prognosis in LALRC patients with anal sphincter involvement after neoadjuvant chemoradiotherapy followed by surgery.MethodsWe analyzed 210 LALRC patients and classified them into DLI group (n = 45) or non-DLI group (n = 165). The exact role of DLI in survival and failure patterns was assessed before and after propensity-score matching(PSM). Finally, 50 patients were matched.ResultsBefore matching, patients in the DLI group had poorer 5-year distant relapse-free survival (DRFS) (P < 0.001), disease-free survival (DFS) (P < 0.001), and overall survival (OS) (P = 0.022) than those in the non-DLI group, with the exception of local recurrence-free survival (LRFS) (P = 0.114). After PSM, the 5-year DRFS, DFS, OS, and LRFS were 51.7% vs. 79.8%(P = 0.026), 51.7% vs. 79.8%(P = 0.029), 71.6% vs. 85.4%(P = 0.126), and 85.7% vs. 92.0%(P = 0.253), respectively, between the two groups. DLI was also an independent prognostic factor for poor DRFS with (Hazard ratio [HR] 3.843, P = 0.020) or without matching (HR 2.567, P = 0.001). The DLI group exhibited a higher rate of distant metastasis before (44.4% vs. 19.4%, P < 0.001) and after matching (48.0% vs. 20.0%, P = 0.037) and similar rates of locoregional recurrence before (13.3% vs.7.9%, P = 0.729) and after matching (16.0% vs.12.0%, P = 1.000).ConclusionsDLI may portend worse DRFS and distant metastasis in LALRC patients with anal sphincter involvement, and this may be an important variable to guide clinicians.

PMON85 Co-occurrence of Carotid Body Tumor, Meningioma and Schwannoma in a Symptomatic Patient, Incidental Findings Vs Genetic Syndrome: A Case Report

Abstract Carotid body tumors, also known as chemodectomas/paraganglionomas; are rare neuroendocrine tumors that arise from parasympathetic ganglionic cells. They are usually benign with incidence of malignancy is &amp;lt;10%. In majority of cases, tumors are asymptomatic and found incidentally on clinical exam or radiological imagining. Their association with other non-neuroendocrine tumors as seen in present case; has not been well documented in literature. Case presentation 43 y/o female with PMH of GERD, obesity, asthma and anxiety disorder who came to endocrine clinic for left middle thyroid lobe nodule(0.9×0.6×0.6cm) evaluation; incidentally noted to have a multilobulated heterogeneous hypo echoic and iso-echoic mildly vascularized solid nodular mass (3.46×1.83×1.93 cm) in the left carotid bifurcation area; splaying the common and the internal carotid arteries on US. Review of systems was positive for left sided neck pain, intermittent palpitations, headaches, anxiety, and sleep disturbances. Clinical exam was remarkable for thyromegaly and a palpable non-tender 3cm left neck mass with no cervical lymphadenopathy. Initial labs were notable for mild elevation of chromogranin A (108.4 ng/ml) with normal levels of TSH, free T3, free T4, plasma metanephrines and 24-hour urinary metanephrines. Considering patient's persistent symptoms; plasma catecholamines levels were done and were negative. MRI soft tissue neck confirmed 2.8 cm lobular mass suggestive of paraganglioma. Metastatic work up was negative. Patient was referred for genetic testing considering young age and to rule out hereditary disorders. Interim, patient presented to the ED with complain of sudden onset lumbar backache without sphincteric involvement; neurological exam was unrevealing but on MRI lumbar spine found to have a 5.7×4.8×4cm lobulated well-circumscribed homogeneous soft tissue mass suggestive of schwannoma. Cervical and thoracic spine imaging was unremarkable. MRI brain showed a 1.1cm enhancing mass in right Meckel cave suggestive of meningioma. PET-DOTATATE scan was performed that revealed left neck mass as intensely avid, Right petrous apex mass as moderately avid and lumbar mass as not avid at all, consistent with the diagnosis of paraganglionoma, meningioma and schwannoma respectively. No evidence of DOTATATE avid nodal/ distant metastatic disease was found. Initially a hereditary etiology was suspected but genetic testing including (VHL, NF1/2, SDHD, SDHB) came back negative. Case was discussed with multidisciplinary teams; Neurosurgery service recommends conservative management of both meningioma and schwannoma at the moment considering benign course. Regarding paraganglioma, as tumor is non-secretory on repeated work up; sympathetic blockade is not warranted and patient is scheduled for pre-op embolization and surgical resection by Head and Neck surgery. Conclusion Paraganglionomas are generally benign non-secretory tumors that usually occur with other neuroendocrine tumors both as hereditary syndromes and sporadic cases. But their association with non-neuroendocrine tumors is mere incidental or has a genetic causation; is still unclear and warrants further research. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

PMON85 Co-occurrence of Carotid Body Tumor, Meningioma and Schwannoma in a Symptomatic Patient, Incidental Findings Vs Genetic Syndrome; a case report.

Abstract Carotid body tumors, also known as chemodectomas/paraganglionomas; are rare neuroendocrine tumors that arise from parasympathetic ganglionic cells. They are usually benign with incidence of malignancy is &amp;lt;10%. In majority of cases, tumors are asymptomatic and found incidentally on clinical exam or radiological imagining. Their association with other non-neuroendocrine tumors as seen in present case; has not been well documented in literature. Case presentation 43 y/o female with PMH of GERD, obesity, asthma and anxiety disorder who came to endocrine clinic for left middle thyroid lobe nodule(0.9×0.6×0.6cm) evaluation; incidentally noted to have a multilobulated heterogeneous hypo echoic and iso-echoic mildly vascularized solid nodular mass (3.46×1.83×1.93 cm) in the left carotid bifurcation area; splaying the common and the internal carotid arteries on US. Review of systems was positive for left sided neck pain, intermittent palpitations, headaches, anxiety, and sleep disturbances. Clinical exam was remarkable for thyromegaly and a palpable non-tender 3cm left neck mass with no cervical lymphadenopathy. Initial labs were notable for mild elevation of chromogranin A (108.4 ng/ml) with normal levels of TSH, free T3, free T4, plasma metanephrines and 24-hour urinary metanephrines. Considering patient's persistent symptoms; plasma catecholamines levels were done and were negative. MRI soft tissue neck confirmed 2.8 cm lobular mass suggestive of paraganglioma. Metastatic work up was negative. Patient was referred for genetic testing considering young age and to rule out hereditary disorders. Interim, patient presented to the ED with complain of sudden onset lumbar backache without sphincteric involvement; neurological exam was unrevealing but on MRI lumbar spine found to have a 5.7×4.8×4cm lobulated well-circumscribed homogeneous soft tissue mass suggestive of schwannoma. Cervical and thoracic spine imaging was unremarkable. MRI brain showed a 1.1cm enhancing mass in right Meckel cave suggestive of meningioma.PET-DOTATATE scan was performed that revealed left neck mass as intensely avid, Right petrous apex mass as moderately avid and lumbar mass as not avid at all, consistent with the diagnosis of paraganglionoma, meningioma and schwannoma respectively. No evidence of DOTATATE avid nodal/ distant metastatic disease was found. Initially a hereditary etiology was suspected but genetic testing including (VHL, NF1/2, SDHD, SDHB) came back negative. Case was discussed with multidisciplinary teams; Neurosurgery service recommends conservative management of both meningioma and schwannoma at the moment considering benign course. Regarding paraganglioma, as tumor is non-secretory on repeated work up; sympathetic blockade is not warranted and patient is scheduled for pre-op embolization and surgical resection by Head and Neck surgery. Conclusion Paraganglionomas are generally benign non-secretory tumors that usually occur with other neuroendocrine tumors both as hereditary syndromes and sporadic cases. But their association with non-neuroendocrine tumors is mere incidental or has a genetic causation; is still unclear and warrants further research. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

Total Neoadjuvant Therapy Is a Predictor for Complete Pathological Response in Patients Undergoing Surgery for Rectal Cancer

IntroductionTotal neoadjuvant therapy (TNT) is a new therapeutic strategy in patients with rectal cancer. We examined the role of TNT, in addition to other pre-operative factors, as a predictor for pathologic complete response (pCR). MethodsA retrospective analysis of all rectal cancer patients who underwent surgery between 2016 and 2021 was conducted. Patients were classified into two groups—pCR group and residual tumor group. Patient data were reviewed and entered into univariate and multivariate analyses to determine predictors of pCR. ResultsA total of 172 patients were treated with neoadjuvant therapy and underwent surgery during the study period. Sixty patients (34.9%) were treated with TNT while 112 (65.1%) were treated with traditional neoadjuvant chemoradiation. The overall pCR rate was 25.6% (44 patients), with 31.6% (19 patients) in patients who received TNT compared to 22.3% (25 patients) in patients who received neoadjuvant chemoradiation (NCRT). Univariate analysis of clinical and radiological factors correlated with pCR demonstrated no significant differences between the two groups in cT stage (p = 0.46), cN stage (p = 0.52), positive circumferential resection margin (CRM) (p = 0.72), tumor location (p = 0.35), symptomatic presentation (p = 0.09), and anal sphincter involvement (p = 0.68). Multivariate logistic analysis demonstrated that only pre-operative TNT (OR:2.35; 95% CI 1.06–5.25; p = 0.03) was predictive of pCR, while extramural vascular invasion (EMVI) was a predictor for lower rates of pCR (OR: 0.28; 95% CI 0.09–0.9; p = 0.03). ConclusionRectal cancer patients undergoing TNT prior to surgery have a higher chance of developing a complete pathologic response. Evaluation of this therapy should be continued and extended to larger numbers of patients to see if the differences we observed are real.

Preoperative MRI accuracy after neoadjuvant chemoradiation for locally advanced rectal cancer.

To evaluate the performance of magnetic resonance imaging (MRI) in restaging locally advanced rectal cancers (LARC) after neoadjuvant chemoradiotherapy (nCRT), with pathologic correlation. 80 patients with LARC treated with neoadjuvant therapy, with restaging MRI and surgery, were enrolled and prospectively reviewed. The diagnostic accuracy of the restaging MRI was assessed for tumor (ymrT), nodal status (ymrN), circumferential resection margin (ymrCRM), extramural vascular invasion (ymrEMVI) and tumoral deposits (ymrN1c) by calculating the sensitivity (Se), specificity (Sp), negative predictive values (NPV) and positive predictive values (PPV). Response to treatment was classified as good response (complete/near complete) vs. poor response (poor/partial response). The agreement between the tumor regression grade at MRI (mrTRG) and pathology (pTRG) was reported, as well the performance of mrTRG to identify good responders. The correlation between restaging MRI and histopathology was assessed by Spearman correlation coefficient. The MRI accuracy ranged between 63.8% and 92.5% for T stage and was 81.3% for N stage. All MRI parameters evaluated at restaging were statistically significant correlated with histopathology evaluation, but EMVI. There was moderate correlation for N and N1c and a positive strong correlation for T, CRM and TRG (Spearman correlation coefficient of 0.390 for mrN1c-pN1c, 0.428 for mrN-pN, 0.522 for mrCRM-pCRM, 0.550 for mrT-pT and 0.731 for mrTRG-pTRG). Diagnostic accuracy of anal sphincter invasion was 91.3%, with a negative predictive value (NPV) of 100%. Accuracy rate varied between 70% for partial response to 93.75% for complete response after nCRT. MR imaging had good accuracy in restaging LARCs after nCRT. Our results showed high MRI accuracy in detecting anal sphincter involvement for low rectal tumors, with high NPV to exclude tumoral invasion. Restaging MRI predicted well the tumor regression grade, with good diagnostic performance in differentiating good responders from poor/partial responders. The accuracy was high for detecting complete response.