Margin Involvement Research Articles

Multi-Centre Study of Progression Factors and Intravesical Recurrence in Patients with Urothelial Carcinoma of the Upper Urinary Tract

Background/Objectives: A retrospective analysis was conducted to identify factors associated with disease progression and intravesical recurrence (IVR) in a multi-centre cohort of patients with upper urinary tract urothelial carcinoma (UTUC) treated surgically between 2015 and 2021. Methods: Progression-free survival (PFS) and IVR-free survival were evaluated using a Kaplan–Meier survival curve and a Log-Rank test. Prognostic factors for progression and IVR were analysed using Cox logistic regression analysis. Results: A total of 170 patients were analysed. Up to 32.9% developed progression within 65.64 ± 3.44 months. Multivariate analysis showed that pT (HR 2.9, 95%CI 1.54–5.48, p = 0.01), margin status (HR 2.89, 95%CI 2.88–57.68, p = 0.01), and lymphovascular involvement (HR 7.97, 95% CI 1.43–44.42, p = 0.02) were independent risk factors for PFS. Up to 25.9% of patients presented with IVR at a mean time of 68.33 ± 3.59 months. A previous diagnosis of bladder cancer (BC) (HR 3.73, 95% CI 1.24–11.22, p = 0.02) and the non-invasive appearance of the tumour on computed tomography were significant risk factors for IVR (HR 0.23, 95% CI 0.05–0.95, p = 0.03). Conclusions: pT stage, margin involvement, and lymphovascular involvement were independent risk factors for UTUC progression. The main risk factor for presenting with IVR after UTUC was a previous diagnosis of BC.

A territory wide follow-up of primary and secondary extramammary Paget disease of two decades - effects of local disease on survival.

Introduction Extramammary Paget disease (EMPD) is an uncommon malignant cutaneous neoplasm that are divided into primary and secondary forms. In this multicenter study, histologically proven cases of primary and secondary EMPD were reviewed for clinical outcomes with subgroup analysis for secondary EMPD. Methodology Cases of EMPD were identified from pathology report of the involved institutions over a period of over two decades. Cases of secondary EMPD were identified review of case notes, radiology, and pathology reports. Clinicopathological and outcome data were retrieved for statistical analysis. Results A total of 109 cases were retrieved, including 19 cases of secondary EMPD, most commonly associated with colorectal (n=6), anal (n=5) and prostatic carcinomas (n=3). A difference was observed between older age and secondary (versus primary) EMPD (p=0.016), but no differences were seen in other clinico-demographical parameters. Male sex (p=0.018), age over 60 years old (p=0.004) and involvement of margins (resectable) (p=0.018) were associated with shorter OS. For DSS, involvement of margins (p=0.009) was an adverse predictor. Secondary EMPD had a shorter DSS than primary EMPD (p=0.005). Multivariable analysis confirmed all above associations (p<0.05). In subgroup analysis for secondary EMPD, margin involvement remained associated with shorter OS (p = 0.007) and DSS (p = 0.003). Conclusions Secondary EMPD is associated with poorer outcomes. Margin involvement is strong and independent indicator of shorter OS and DSS, including secondary EMPD. Resectability is a strong predictor of favorable outcome and excision with clear margins should be attempted when surgically feasible.

Reply to Zhang, ‘Comment on: The mode of circumferential margin involvement in rectal cancer determines its impact on outcomes: A population-based study’

Reply to Zhang, ‘Comment on: The mode of circumferential margin involvement in rectal cancer determines its impact on outcomes: A population-based study’

Comment on "The mode of circumferential margin involvement in rectal cancer determines its impact on outcomes: A population-based study"

Comment on "The mode of circumferential margin involvement in rectal cancer determines its impact on outcomes: A population-based study"

Colon Cancer With Bladder Invasion: A Single Center Experience.

The aim of our study was to investigate the outcome of colon cancer with bladder invasion after surgical intervention. Between 2011 and 2022, a total of 41 patients diagnosed with colon cancer and bladder invasion underwent surgical procedures at Taichung Veterans General Hospital. The impact of various risk factors on overall survival (OS) was assessed using Kaplan-Meier analyses and Cox proportional hazards models. Among the enrolled patients, 21 underwent radical cystectomy, while 20 underwent partial cystectomy. Twelve had tumors located in the rectum, 19 in the sigmoid colon, and 10 in both the rectum and sigmoid colon. The median OS was 71.8 months in stage 2, 50.8 months in stage 3, and 11.2 months in stage 4 (p=0.061). Median OS was 71.8 months in patients with negative surgical margins and 10.5 months in those with positive surgical margins (p=0.003). In multivariate regression analysis, positive surgical margins [hazard ratio (HR)=3.64, 95% confidence interval (CI)=1.28-10.34, p=0.015] and emergency operations (HR=4.57, 95%CI=1.34-15.55, p=0.015) significantly impacted OS. Complete resection of colon cancer with bladder invasion can yield excellent oncologic outcomes. The decision between partial and radical cystectomy should balance surgical margin clearance and the preservation of quality of life. Both surgical margin involvement and emergency operations are independent risk factors for OS.

Effect of Occlusal and Axial Thickness on the Fracture Load of Implant-Supported Monolithic Zirconia Crowns.

To evaluate the fracture load of monolithic zirconia crowns with implant screw holes, focusing on variations in occlusal and axial thicknesses, and to assess the interaction between these variables. Six different prostheses were designed using CAD software, varying in occlusal thickness (0.5 mm, 1.0 mm) and axial thickness (0.4 mm, 0.8 mm, 1.2 mm) based on the height and thickness differences of the titanium implant abutment. Twelve specimens per design were created by milling zirconia blocks and titanium abutments. These specimens were cemented with resin and subjected to thermomechanical aging (50 N, 200,000 cycles, 5°C-55°C, 30 seconds dwell time) using a chewing simulator. Static loading was applied using a universal testing machine at a rate of 0.5 mm/min until fracture occurred, and the load value (N) at the moment of the initial fracture was recorded. Fracture pattern and surface analyses were performed. Statistical analyses included two-way analysis of variance, Tukey HSD test, multiple regression analysis, and Fisher's exact test. Both occlusal and axial thicknesses significantly influenced the fracture load (P < .05), with a significant interaction between them (P < .05). An occlusal thickness of 1.0 mm exhibited a significantly higher fracture load compared to 0.5 mm (P < .05). An axial thickness of 1.2 mm showed a significantly higher fracture load compared to 0.4 mm and 0.8 mm (P < .05). The difference in axial thickness between 0.8 mm and 1.2 mm had a more substantial impact on fracture load than the difference in occlusal thickness between 0.5 mm and 1.0 mm (P < .05). Fractographic analysis showed that the thin axial wall exhibited twist hackles without involvement of the crown margin, whereas the thick axial wall exhibited no hackles and a more catastrophic failure involving the crown margin. For monolithic zirconia crowns with implant screw holes, when sufficient occlusal thickness cannot be achieved, an axial thickness of at least 1.2 mm is recommended to ensure higher fracture resistance.

Application value of SOMATOM Force computed tomography in assisting the preoperative localization of colorectal cancer resection surgery

Background The objective of this study was to assess the application value of SOMATOM Force computed tomography (CT) in assisting the preoperative localization of colorectal cancer resection surgery. Method Retrospectively, the medical data of 120 inpatients with colorectal cancer were collected. The Kappa consistency test was used to evaluate diagnostic consistency in the localization and staging of colorectal cancer. The diagnostic value of preoperative SOMATOM Force CT detection was analyzed. Results In 120 colorectal cancer patients, the accuracy of SOMATOM Force CT for preoperative localization, T staging, and N staging of colorectal cancer were 91.7% (kappa = 0.837), 88.3% (kappa = 0.772) and 91.7% (kappa = 0.773), respectively. Among 45 rectum cancer patients, there were 19 positive cases with circumferential resection margin involvement, and the accuracy of SOMATOM Force CT detection was 86.7% (kappa = 0.767). The sensitivity, specificity, positive predictive value, and negative predictive value of SOMATOM Force CT detection in evaluating the circumferential resection margin involvement of rectum cancer were 78.95%, 96.15%, 93.75%, and 86.21%, respectively. Conclusions There was an important application value of SOMATOM Force CT in assisting the preoperative localization and tumor staging of colorectal cancer resection surgery. There was a good diagnostic value of preoperative SOMATOM Force CT detection in evaluating the circumferential resection margin involvement of rectum cancer.

From Insight to Impact: Improving Mesorectal Evaluation Standards through Resident Educational Intervention

Abstract Introduction/Objective The completeness of total mesorectal excision (TME) and involvement of the circumferential radial margin (CRM) significantly impact local recurrence and survival rates in rectal cancer. Accurate gross examination to assess mesorectal status is crucial, not only for patient prognosis but also for evaluating surgical quality. Methods/Case Report We implemented a quality assurance initiative to enhance mesorectal quantification and CRM assessment by pathology trainees. Low anterior resection specimens received between January 2022 and December 2023 were included, with 2022 as the pre-intervention period and 2023 post-intervention. In December 2022, an educational session was conducted, emphasizing rectal resection specimens’ types and the importance of mesorectal and CRM assessment. Periodic reminder emails reinforced these concepts. Results (if a Case Study enter NA) We identified a total of 35 cases in the study: 20 pre-intervention arm and 15 post-intervention arm. Mesorectal quantification and CRM assessment and documentation improved significantly post- education, rising from 70% (14 of 20 cases) to 93% (14 of 15 cases) (p &amp;lt; 0.0001). Conclusion In conclusion, our study underscores the critical role of meticulous gross examination in assessing mesorectal status, serving not only as a prognostic indicator but also in guiding surgical precision and rectal cancer management. Further, our findings emphasize the transformative potential of education-driven interventions in enhancing the quality of mesorectal evaluation, reinforcing the pivotal role of pathologists and pathology trainees in shaping therapeutic strategies and ultimately improving rectal cancer patient care.

Outcomes of a modified technique of partial parotidectomy and novel parotid tumour position classification from a single surgeon prospective database.

Conservative parotidectomy for benign tumours reduces facial nerve palsy, without increasing local recurrence. We report a modified technique of partial parotidectomy and using a novel description of tumour position, explore relationships between tumour position and histological margins, facial nerve palsy and local recurrence. A prospectively collected single surgeon parotidectomy database was analysed, including tumour location (superficial/deep lobe; central/peripheral) and outcomes. A partial parotidectomy identified the facial nerve and the proximal portion of its branches with a macroscopically clear resection margin. Mean follow up was 5.9 years for pleomorphic adenomas. Three hundred and three patients underwent parotidectomy; 257 (84.8%) were superficial and 46 (15.2%) deep lobe. Tumour position was recorded in 291: 236 (81.1%) were peripheral tumours and 55 (18.9%) central. Histological margin involvement was similar in central and peripheral tumours, both overall and for superficial and deep lobe tumours, but was commoner in central deep lobe tumours, (P = 0.003). Temporary partial facial nerve palsy occurred in 21 (6.9%), with one permanent partial nerve palsy (0.3%). Deep lobe tumours and total parotidectomy were associated with facial nerve palsy (P = 0.01). Facial nerve monitoring reduced the risk of palsy (P < 0.01). Local recurrence of pleomorphic adenomas was uncommon, occurring in 3 (2.0%) of 151 patients. This series confirms the safety and adequacy of more conservative partial parotidectomy for benign tumours, highlighting most tumours are peripheral, but not more prone to histological margin involvement or local recurrence, and with routine intraoperative facial nerve monitoring, is achieved with low facial nerve palsy rates.

7200 A Unique Case Of Hypercalcemia From Primary Hyperparathyroidism With Thymoma And Concurrent Pulmonary Tuberculosis

Abstract Disclosure: S. Jing Hang Randy: None. L. Huiling: None. Background: Several case reports have reported the rare association of thymoma with primary hyperparathyroidism. We describe a unique case of hypercalcemia with such association but was also found to have concurrent pulmonary tuberculosis. Clinical Case: A 50-year-old Indian female with a significant history of anterior mediastinal mass underwent median sternotomy with mass resection and was found to have peri-operative hypercalcemia. Her only complaint was chronic cough. Initial investigations showed high adjusted calcium 2.78 mmol/L (2.15– 2.50 mmol/L), normal phosphate 1.1 mmol/L (0.8– 1.4 mmol/L) and high PTH 24.7 pmol/L (1.6– 6.9 pmol/L). Apart from the mediastinal mass, a whole-body CT scan showed multiple prominent mediastinal lymph nodes with non-specific subcentimetre lung nodules. The post-operative finding was a Type AB thymoma with necrotizing granulomatous inflammation in adjacent station I lymph node. Differentials for patient’s hypercalcemia included primary hyperparathyroidism, malignancies such as lymphomas and infectious causes in particular tuberculosis. Her 25-OH Vitamin D was low at 9 ug/L (30 - 100 ug/L), 1,25-dihydroxyvitamin D was elevated at 205 pg/mL (18-64 pg/mL) while creatinine, ALP, serum ACE and PTHrP were unremarkable. She was subsequently admitted for worsening hypercalcemia, fever and left pleural effusion with generalized lymphadenopathy where she underwent an Endobronchial Ultrasound-guided Transbronchial Needle Aspirate of station IV lymph nodes before being started on tuberculosis treatment. The AFB culture showed Mycobacterium Tuberculosis Complex thereafter. Parathyroid sonography revealed a 2.2cm x 0.9cm x 0.8cm lobulated hypoechoic lesion posterior to the inferior pole of left thyroid lobe. However, a confirmatory sestamibi scan could only be done 6 weeks post-thymectomy given the raw surgical bed, with a possibility of false-negative result for cervical parathyroid adenoma given a recent thymectomy. It subsequently showed a hyperfunctioning left inferior parathyroid nodule with no other suspicious focal uptake in the neck or mediastinum. Patient underwent a focused left parathyroidectomy. Histology showed features consistent with parathyroid adenoma. A stepwise trajectory of her calcium normalization was observed with hydration, intravenous zoledronic acid for her osteoporosis, tuberculosis treatment, adjuvant radiation therapy for her thymoma with margins involvement, and parathyroidectomy. Conclusion: This case illustrates the challenges faced while considering localizing scans for primary hyperparathyroidism with recent thymectomy given the common embryological origin of inferior parathyroid and thymus. It also demonstrates the possible co-existence of separate pathologies in hypercalcemia and the need to exercise prudent clinical judgement to further evaluate for these various etiologies. Presentation: 6/2/2024

8769 A Case of Metastatic and Catecholamine Producing Bilateral Pheochromocytoma in a Patient with RET Gene Mutation

Abstract Disclosure: R.A. Mayers: None. A. Szafran-Swietlik: None. RET mutation, observed in multiple endocrine neoplasia type 2 syndromes, is implicated in the development of pheochromocytomas of the kinase signaling cluster. Such tumors have lower metastatic risk and adrenergic production compared to the ones from the other clusters. We present a case of a metastatic, bilateral, small and biochemically active pheochromocytoma .This is the case of a 27-year-old man diagnosed with MEN 2A. He underwent total thyroidectomy due to medullary thyroid carcinoma at 2 years old. He was deemed cured and started on levothyroxine replacement. Since then, his plasma metanephrines by liquid chromatography-mass spectrometry and urine metanephrines done in a yearly basis as screening, were always within range of normality. Over the years, he developed substance abuse disorder with use of Kratom and methamphetamines and was admitted in a rehabilitation center multiple times in the last three years. During this time, the patient was reported to be slightly tachycardiac which was initially attributed to the use of substances. On the last year, an echocardiogram done as evaluation of his tachycardia showed an ejection fraction of 35%. Later, his annual metanephrine levels were markedly elevated (free metanephrine: 137 pg/mL and free normetanephrine : 157 pg/mL, normal ranges reported as less than 57 pg/mL and less than 148 pg/mL respectively). Abdominal tomography showed a right adrenal nodule of 1.2 cm and a left adrenal nodule of 1.6 cm, both with more than 10 Hounsfield Units. A Metaiodobenzylguanidine scan revealed a left adrenal nodule of 1.8 cm with diffuse radiotracer uptake, a right adrenal nodule of 1.2 cm with radiotracer activity and 3 subtle areas of focally increased radiotracer activity in the liver, two in left hepatic lobe and other in posterior right upper lobe. He underwent bilateral adrenalectomy with cortical sparring. Pathology results evidenced a left adrenal with a unifocal mass of 1.8 cm and a right adrenal with a mass of 1.2 cm , both without lymphovascular, capsular, local invasion or necrosis, a mitotic rate of 1-2 without atypical mitosis, not encapsulated with clean margins and positive for synaptophysin , chromogranin and S100 stains. An additional mass of 0.7 cm on the right adrenal gland was described with similar characteristics to the described before except for the involvement of the surgical margins. Currently on the literature there are different opinions regarding screening approach for pheochromocytomas in the presence of RET mutations. There are not strong recommendations regarding the use of imaging as a screening tool in this group of patients. It is important to consider that there are cases, as the one described in this report, that might present metastatic disease even with the presence of small pheochromocytomas that belong to the cluster of kinase signaling. Presentation: 6/3/2024

Laparoscopic adrenalectomy performed with the Endo GIA™ Stapler as an easy and safe approach.

The purpose of this study was to determine whether the application of the Endo GIA™ Stapler (Medtronic, Dublin, Ireland) could be helpful in the dissection of adrenal tumors in complicated cases. We retrospectively reviewed the records of patients who underwent laparoscopic adrenalectomy between 2012 and 2022 at the College of Medicine, Yeouido St. Mary's Hospital, The Catholic University of Korea (Seoul, Republic of Korea). We adopted the Endo GIA™ Stapler (Medtronic) to seal vessels around adrenal gland and separate adrenal gland completely when it was difficult to perform meticulous dissection and isolation with laparoscopic instruments. Thirteen patients who underwent laparoscopic adrenalectomy with Endo GIA™ staplers were reviewed and compared with 45 other patients who underwent laparoscopic adrenalectomy without Endo GIA™ staplers. There were no statistical differences between the two groups in demographic, tumor-related, and diagnostic variables. Surgical outcomes such as margin involvement, bleeding, operation duration, rate of conversion to open surgery, blood transfusion, complications, and recurrence were not different between the two groups. In our experience, applying of the Endo GIA™ Stapler (Medtronic) in laparoscopic adrenalectomy is a feasible and acceptable approach.

TERT mutations and aggressive histopathologic characteristics of radioiodine-refractory papillary thyroid cancer.

Radioiodine (RI) ablation following thyroid-stimulating hormone suppression is an effective treatment for papillary thyroid cancer (PTC), typically leading to favorable outcomes. However, RI-refractory tumors exhibit aggressive behavior and poor prognoses. Recent studies highlight the role of genetic abnormalities in PTC signaling pathways, including the activation of telomerase reverse transcriptase (TERT), and the correlation of mutations with adverse outcomes. This study analyzed mutations in BRAF V600E and the TERT-promoter genes, comparing clinicopathological features between RI-refractory and RI-responsive PTCs. Among 82 RI-refractory patients, formalin-fixed, paraffin-embedded tissues from initial surgeries were available for 26. Another 89 without distant metastasis over 5 years formed a matched RI-responsive control group. Histopathologically, RI-refractory PTCs showed increased frequencies of small tumor clusters without fibrovascular cores, hobnail features, and a high height-to-width ratio of tumor cells. These tumors were more likely to exhibit necrosis, mitosis, lymph node metastasis, extrathyroidal extension, and involvement of resection margins. TERT-promoter mutations were statistically significantly associated with these aggressive clinicopathologic features. Immunohistochemically, decreased expression of sodium iodide symporter and thyroglobulin stimulating hormone receptor proteins was common in RI-refractory PTCs, along with lower levels of oncogenic proteins such as vascular endothelial cell growth factor, vascular endothelial cell growth factor receptor 2, and nuclear factor kappa-light-chain-enhancer of activated B cells. Total loss of PTEN expression was occasionally observed. In contrast, all cases tested positive for cytoplasmic β-catenin. RI-refractory PTCs are linked to TERT mutations and exhibit specific aggressive histopathologic features, particularly in tumor centers.

Perineal-First Approach in Robotic Abdominoperineal Resection.

Although abdominoperineal resection (APR) is required for rectal cancer invading the levator ani muscle, its curative outcomes remain poorer than those of other rectal surgeries.1-3 In particular, the anatomic complexity around the anterior wall of the rectum increases the technical difficulty during APR, resulting in a high frequency of margin involvement that causes local recurrence. In this video, we present the technical details of a robotic perineal-first APR approach. For a 46year-old man, locally advanced rectal cancer invading the levator ani muscles was diagnosed. Although total neoadjuvant therapy (8 cycles of induction FOLFOXIRI followed by chemoradiotherapy 50.4 Gy) decreased the tumor size, invasion was suspected still to remain. Therefore, robotic APR was performed. Written informed consent was obtained from the patient. For the perineal-first approach, we created a circular incision around the anus, then divided the fat tissues of the ischiorectal fossa until the levator ani muscle was exposed on both sides. Posterior and anterior dissections were performed along the coccyx and external anal sphincter, respectively. After placement of a lap protector to maintain air-tightness, the robotic approach was initiated. Posterior dissection was performed along the coccyx, then was connected to the already-dissected space created earlier by the perineal approach. Next, the levator ani muscle was divided from the dorsal to the lateral side. Finally, anterior dissection was performed along the prostate, followed by division of the rectourethral muscle, the smooth muscle fibers running vertically. The creation of the already-dissected space on the perineal side offers advantages of robotic manipulation from the abdominal side, especially anterior dissection. We performed robotic APR using the perineal-first approach for 17 consecutive patients (12 men and 5 women) between 2019 and 2023. All 17 patients achieved complete total mesorectal excision with negative margins. The mean time required for the perineal approach was about 25 min. In anterior dissection using the robotic approach, division of the smooth muscle fibers at the perineal body (i.e., rectourethral muscle in males4 or muscular intermingling in females5) was reproducibly performed in both males and females. Robotic APR with a perineal-first approach can be advantageous in ensuring surgical margin safety (especially for the anterior aspect of the rectum).

FP1.1 - The relationship between tumour necrosis, the tumour microenvironment, systemic inflammation, body composition and survival in patients with operable colon cancer. Does tumour necrosis drive systemic inflammation and cachexia?

Abstract Introduction The prognostic value of the systemic inflammatory response and its incorporation into the definition of cancer cachexia (GLIM) is now established. However, the basis of the relationship between the tumour, its environment and the systemic inflammatory response is not clear. The aim of the present study is to examine this hypothesis in greater detail. Methods A total of 473 patients were included. Host and tumour characteristics were assessed including tumour cell signaling pathways, CT derived body composition and systemic inflammation (as assessed by SIG). Categorical variables were analysed using χ2 test for linear-by-linear association, or χ2 test for 2 by 2 tables. Survival analysis was carried out using univariate Cox regression. Results Tumour necrosis was associated with age (p&amp;lt;0.01), tumour location (p&amp;lt;0.01), T-stage (p&amp;lt;0.001), margin involvement (p&amp;lt;0.05), SIG (p&amp;lt;0.001), SMI (Martin, p&amp;lt;0.01), SMI (Dolan, p&amp;lt;0.01), SMD (Dolan, p&amp;lt;0.05) and 5-year survival (p&amp;lt;0.001). No association was found between tumour necrosis and signalling markers of the IL-6/JAK/ STAT and NF-KB pathways. On univariate survival analysis age (p&amp;lt;0.001), ASA (p&amp;lt;0.001), T-stage (p&amp;lt;0.001), N-stage (p&amp;lt;0.001), tumour budding (p&amp;lt;0.05), venous invasion (p&amp;lt;0.01), adjuvant therapy (p&amp;lt;0.01), margin involvement (p&amp;lt;0.001), necrosis (p&amp;lt;0.01), SIG (p&amp;lt;0.001), MUST (p&amp;lt;0.001), BMI (p&amp;lt;0.05), sub cutaneous obesity (p&amp;lt;0.001), visceral obesity (p&amp;lt;0.05), Sarcopenia (Martin, p&amp;lt;0.05), Sarcopenia (Dolan, p&amp;lt;0.01), Myosteatosis (Dolan, p&amp;lt;0.05) GMS (p&amp;lt;0.001), Ki67 (p&amp;lt;0.01) and TSP (p&amp;lt;0.01) were independently associated with overall survival. Conclusion There is a clear association between tumour necrosis, the SIR and body composition in patients with colon cancer. These results are consistent with the hypothesis that tumour necrosis and the subsequent inflammatory response results in profound changes in body composition.

A Real-World Analysis of Oncological Outcomes in Patients with Oral Squamous Cell Carcinoma Requiring Marginal Mandibulectomy for Achieving Clear Surgical Margins

Introduction Marginal mandibulectomy (MM) offers a conservative alternative to segmental resections for patients with oral squamous cell carcinoma (OSCC) requiring clear margins without evident bone invasion. Despite its potential benefits, real-world outcomes related to surgical margins and oncological outcomes have not been studied sufficiently. Methods This ambispective cohort study analyzed 183 patients undergoing MM from January 2015 to March 2021 to achieve clear margins without clinical bone involvement. The primary objective is to assess the disease-free survival (DFS) in patients with OSCC requiring MM to achieve clear surgical margins, and the secondary objective is to assess the impact of microscopic bone involvement on these outcomes. Kaplan–Meier estimates facilitated the survival analysis. Results The cohort primarily comprised males (83.2%) with a median age of 50 years, the predominant subsite being the bucco-alveolar complex (94%). Microscopic bone involvement was found in 8.74% of patients. The distribution of surgical margins was 84.24% negative, 15.22% close, and 0.54% positive. The cohort's 3-year DFS and overall survival (OS) rates are 65 and 70%, respectively. Patients with microscopic bone involvement experienced lower DFS (odds ratio [OR] = 0.251, p = 0.013), and perineural invasion was also a significant negative prognostic factor for DFS (OR = 0.4, p = 0.01). Statistical analyses revealed significant differences in survival distributions based on bone involvement (p = 0.049). Conclusion While MM can achieve favorable surgical margins in selected OSCC patients, microscopic bone involvement compromises DFS. Given the low incidence of bone involvement and high rate of negative margins, more conservative approaches might be justified in select patients. However, these findings require further validation in a larger cohort.

Prognostic Impact of Surgical Margin Status on Overall Survival of Patients with Early Breast Cancer: A Retrospective Analysis from the Department for Women's Medicine at Charité - University Hospital Berlin.

The impact of surgical margins on the prognosis of early breast cancer remains uncertain, particularly in the context of modern treatment approaches. This study aimed to investigate whether involved margins after surgery for early breast cancer affect overall survival. We conducted a retrospective analysis of 3767 patients who underwent surgery for primary breast cancer or carcinoma in situ between 2006 and 2022 at Charité - University Hospital Berlin. Survival analysis based on margin status and a subsequent multivariate Cox regression analysis were conducted. With a median follow-up of 72.2 months, clear margins were achieved in 81.4% of patients (n=3068) after primary surgery, while 16.2% (n=610) required re-excision. Only 2.4% of patients (n=89) had definitively involved margins. Margin involvement was more common in hormone receptor-positive disease, lobular subtype, carcinoma in situ, or locally advanced tumors, but less frequent in patients with previous neoadjuvant chemotherapy or triple-negative breast cancer. The Kaplan-Meier survival curves showed a significant separation with worse outcomes for patients with definitive R1 resections. However, the multivariate Cox regression analysis detected no statistically significant difference in overall survival based on margin status. Breast conserving surgery (HR 0.66; 95% CI 0.54-0.81) and HER2 overexpression (HR 0.65; 95% CI 0.48-0.89) were associated with improved survival. Patients who underwent breast-conserving surgery in our study demonstrated favorable outcomes compared to patients after mastectomy. Although margin status did not significantly affect overall survival, larger multicenter studies are needed to evaluate the prognostic implications of margin involvement in breast cancer treatment in different tumor stages, tumor subtypes and local and systemic treatments.

Factors associated with leakage after reversal of protective stoma in patients with locally advanced rectal cancer following curative resection and anastomosis

IntroductionAnastomotic leakage (AL) is a significant complication in colorectal surgery with numerous general and specific risk factors. The determinants of colorectal AL following the reversal of a protective defunctioning ileostomy remain unclear and warrant further investigation. Material and methodsData from April 2008 to December 2014 were collected and retrospectively reviewed for 361 consecutive patients who underwent protective ileostomy reversal following curative resection with anastomosis for rectal cancer. The baseline, treatment, and oncological variables of patients associated with post-reversal AL were evaluated using univariate and multivariate logistic regression analysis. The impact of AL on long-term survival outcomes was assessed using Kaplan-Meier survival analyses. ResultsIn a study of 361 patients, 52 (14.4 %) experienced leakage following stoma reversal, manifesting at a median of 5.7 months. Multivariable logistic regression analysis revealed that an anastomosis located less than 7 cm from the anal verge (OR 2.82, p = 0.008), a side-to-end anastomotic configuration (OR 2.02, p = 0.036), involvement of the circumferential resection margin (OR 6.46, p = 0.043), and adjuvant radiotherapy (OR 4.69, p = 0.003) significantly predicted post-reversal AL. Notably, five-year overall survival (63.4 % vs. 90.3 %, p < 0.0001) and disease-free survival (46.9 % vs. 71.1 %, p = 0.001) were significantly lower in patients with post-reversal AL. ConclusionsOur analysis identified several clinicopathological factors associated with post-reversal AL, which is linked to a significant decrease in long-term survival and oncological outcomes. Alleviating these adverse effects necessitates ensuring early detection and effective management of leaks among high-risk patients.

358. IMPLICATIONS ON OVERALL SURVIVAL FROM POSITIVE CIRCUMFERENTIAL RESECTION MARGINS IN OESOPHAGEAL CANCER PATIENTS AT A TERTIARY REFERRAL CENTRE IN ENGLAND

Abstract Background The oesophagogastric (OG) tertiary referral centre at our Trust was established in March 2009.It caters to a catchment population of approximately 1.6 million. Oesophageal cancer is a morbid disease contributing to 18% of cancer mortalities worldwide. Involvement of circumferential resection margin (CRM) is an indicator of poor prognosis. The aim was to calculate the microscopic positive resection rate in patients undergoing resections for oesophageal cancers, assess disease free survival (DFS) and overall survival (OS) in this cohort. Methods Patients undergoing oesophageal resections for cancer at our OG unit who satisfied the inclusion criteria - age&amp;gt;18, operation with curative intent, adenocarcinoma and squamous cell cancer with a microscopic positive resection margin (R1) were included. Data was collected from the electronic patient record (Quadramed). Retrospective analysis was performed using MS Excel and IBM SPSS statistics Ver 27. Results A total of 640 oesophageal cancer resections performed between April 2009 - March 2023, who satisfied the inclusion criteria were included. Median age at surgery was 66 years. The R1 rate was 40% in our cohort (R0:R1 =380:260). Male to female ratio in the R1 cohort was 4:1. 98% (255 patients) had T3/T4 disease. 47.7% (124 patients developed recurrence. Of these, 83.8% (104 patients) developed distant metastasis and 16.2 %(20 patients) had locoregional metastasis. Median time to recurrence was 12 months and disease-free survival was also12 months. The OS at one year of 81% (140/260) was comparable to national data. Conclusion We conclude that locally advanced tumour staged T3 and above is the most likely cause for higher rate of CRM positivity. Other factors that could contribute is the lack of serosal layer in the oesophagus and the practise of ex situ removal of nodes from the main specimen in theatre which could potentially lead to stripping of the adventitia thus making the CRM falsely R1 during pathological staging. The R1 status however does not seem to affect the overall survival rate.

311. PROGNOSTIC VALUE OF DIFFERENT CIRCUMFERENTIAL MARGIN SITES IN OESOPHAGEAL CANCER: A 10-YEAR COHORT STUDY

Abstract Background There’s a growing interest towards the prognostic value of circumferential resection margin (CRM) involvement in oesophageal cancers. However, there is no sufficient data about the association of the site-specific CRM and survival. In this study, we analysed the influence of different involved CRM sites on survival. Methods This study included patients who had curative oesophagectomy for oesophageal cancer between 2010 till June 2021. Follow up till April 2022 was achieved. Patients with involved proximal or distal margins were excluded. The sites of CRM were defined anatomically to anterior (pericardial), posterior (aorta), lateral (pleurae). The outcomes between different CRM margins were retrospectively analysed. The long-term follow up data was obtained via direct contact with the patients during our oncological clinics, cross-checked with our hospital/national patients’ electronic databases. Results 117 patients had CRM-positive after curative oesophagectomy during the study period. 33 cases had multi-involved CRM sites, while 84 patients had single involved CRM site. Posterior margins were the most common involved site 37/117 (31.6%). No differences in baseline pathological criteria (pT, pN stages and type of cancer) and neoadjuvant therapy. Positive anterior margins carried the worst overall (OS) and disease-free (DFS) survival compared to lateral and posterior margins (OS: 29 vs 41 vs 32 months respectively, p-value 0.37, DFS: 19.2 vs 32.1 vs 28.7 months respectively, p-value 0.39). Multi-involved CRM sites led to worse OS and DFS in comparison with single involved CRM site (OS: 19 vs 32 months respectively, p-value 0.008, DFS: 12.1 months vs 27.6 months respectively, p-value 0.05). Conclusion The site of involved CRM should be rigorously assessed in oesophagectomy specimens. The involved margin sites within CRM had different survival rates, with inferiority towards anterior resection margins. Larger studies are required to better evaluate the prognostic significance of various CRM sites.