Prognostic effect of microscopically negative but close resection margin in gastric cancer.

INTRODUCTION: Microscopically positive resection margin (RM) following curative surgery has been linked to disease recurrence in gastric cancer (GC), but the impact of microscopically negative but close RM (CRM) remains unclear. This study aimed to evaluate the prognostic implications of a CRM of ≤0.5 cm in GC patients. METHODS: A retrospective review of the institutional GC database identified 1958 patients who underwent curative gastrectomy for pathologically proven GC between January 2011 and December 2015. The patients were categorized into CRM (RM ≤0.5 cm) and sufficient RM (SRM, RM >0.5 cm) groups. The impact of CRM on recurrence-free survival (RFS) and overall survival (OS) was analyzed compared to the SRM group. RESULTS: The cohort comprised 1264 patients with early GC (EGC, 64.6%) and 694 with advanced GC (AGC, 35.4%). Forty-four patients (2.2%) had RM of ≤0.5 cm. CRM was associated with worse RFS in AGC (5-year RFS in the CRM vs. SRM groups; 41.6% vs. 68.7%, p = 0.011); however, the effect on OS was not significant (p = 0.159). Multivariate analysis revealed that CRM was an independent prognostic factor for RFS (hazard ratio [HR] 2.035, 95% confidence interval [CI] 1.097-3.776). In AGC, the locoregional recurrence rate was significantly higher in the CRM group than in the SRM group (15.4% vs. 4.9%, p = 0.044). CONCLUSION: CRM of ≤0.5 cm was a significant prognostic factor for RFS in GC patients and was associated with a significant increase in locoregional recurrence in AGC.

Impact of Margin Status on Local Recurrence in Patients with Breast Cancer Undergoing Breast-Conserving Surgery After Neoadjuvant Chemotherapy: A Retrospective Multi-Institutional Cohort Study.

BACKGROUND: Questions have been raised as to an increased risk of local recurrence with breast-conserving surgery (BCS) post NAC highlighting the uncertainty around optimal margin width in this patient population. We examined the association between margin status and local recurrence-free survival (LRFS) in patients who underwent BCS following NAC. METHODS: We performed a retrospective cohort study of adult female patients with stage I-III breast cancer who underwent NAC followed by BCS between 2012 and 2021 at two cancer centers. Margins were categorized as "close" if they were < 1 mm. RESULTS: The full cohort included 544 patients with a median age of 53 years (interquartile range [IQR] 44-64). Pathologic complete response (pCR) was achieved in 41.2% of the overall cohort (n = 224). Of the 320 with residual disease, 29.4% (n = 94) had at least one close margin, and 10.9% (n = 35) had ≥2 close margins. Median follow-up was 55 months (IQR 32-83); 4.8% had an ipsilateral breast recurrence (n = 26). Patients with pCR had a higher 5-year LRFS than those with residual disease (98.0% vs. 91.6%, p = 0.02). There was no difference in 5-year LRFS between the margin categories (clear vs. 1 close margin vs. ≥2 close margins) in those with residual disease (92.2% vs. 88.9% vs. 92.9%) (p = 0.78). CONCLUSIONS: In patients undergoing BCS post-NAC, those who achieved pCR had a significantly higher LRFS compared with those with residual disease at the time of surgery, but LRFS was not associated with margin width nor the number of close margins.

Current patterns of care and outcomes for dermatofibrosarcoma protuberans: An international multi-institutional collaborative.

BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is a cutaneous sarcoma with an infiltrative growth pattern that makes it challenging to clear margins. High quality data regarding DFSP natural history, management, and outcomes are limited. METHODS: Data were retrospectively collected for adult DFSP patients who underwent resection at 10 institutions in eight countries. Demographics, tumor characteristics, treatment strategies, and outcomes were analyzed. RESULTS: Analysis included 347 patients consisting of young (median, 42 years), White (76.2%), males (54.2%) with truncal lesions (57.3%). The majority (76.8%) were symptomatic at presentation. Preoperative imaging was used in 55.9% of cases. Diagnosis was established with excisional biopsy in 50.9% versus incisional biopsy in 25.0% of cases. Despite planned margins of >1.0 cm in 67.4% of cases, only 69.0% of patients achieved R0 resection. Twenty-two percent of patients underwent at least one re-excision. R0 resection was achieved at a second procedure in 80.2% and a third procedure in 86.2%. Ultimately, R0 resection was feasible in 89.5% of all patients. Fibrosarcomatous transformation (FST) was observed in 12.6%. In total, 6.6% (N = 23) recurred (17 local, six distant). Of the six distant recurrences, 50.0% had FST. With a median follow-up of 47.0 months, disease-specific survival rate was 98.8%. In multivariable analysis, R0 margins at index resection were associated with wider circumferential margins and non-FST histology. CONCLUSIONS: In this international, multicenter collaborative, DFSP practice patterns were heterogeneous but achieved favorable recurrence rates and survival. Multiple excisions to clear margins remain commonplace and can inform future efforts to optimize margin selection.

Surgical and Oncologic Outcome following Sacrectomy for Primary Malignant Bone Tumors and Locally Recurrent Rectal Cancer.

INTRODUCTION: Bone sarcoma or direct pelvic carcinoma invasion of the sacrum represent indications for partial or total sacrectomy. The aim was to describe the oncosurgical management and complication profile and to analyze our own outcome results following sacrectomy. METHODS: In a retrospective analysis, 27 patients (n = 8/10/9 sarcoma/chordoma/locally recurrent rectal cancer (LRRC)) were included. There was total sacrectomy in 9 (incl. combined L5 en bloc spondylectomy in 2), partial in 10 and hemisacrectomy in 8 patients. In 12 patients, resection was navigation-assisted. For reconstruction, an omentoplasty, VRAM-flap or spinopelvic fixation was performed in 20, 10 and 13 patients, respectively. RESULTS: With a median follow-up (FU) of 15 months, the FU rate was 93%. R0-resection was seen in 81.5% (no significant difference using navigation), and 81.5% of patients suffered from one or more minor-to-moderate complications (especially wound-healing disorders/infection). The median overall survival was 70 months. Local recurrence occurred in 20%, while 44% developed metastases and five patients died of disease. CONCLUSIONS: Resection of sacral tumors is challenging and associated with a high complication profile. Interdisciplinary cooperation with visceral/vascular and plastic surgery is essential. In chordoma patients, systemic tumor control is favorable compared to LRRC and sarcomas. Navigation offers gain in intraoperative orientation, even if there currently seems to be no oncological benefit. Complete surgical resection offers long-term survival to patients undergoing sacrectomy for a variety of complex diseases.

Local recurrence after endoscopic submucosal dissection of gastric neoplastic lesions: special attention should be given also to safety margins.

INTRODUCTION: The incidence of local recurrence following gastric endoscopic submucosal dissection (ESD) remains a clinical concern. We aimed to evaluate the impact of narrow safety margin (< 1 mm) on the recurrence rate. METHODS: A retrospective cohort study was conducted across two centers. Cases of R0-ESD with subsequent recurrence were compared to matched controls in a 1:2 ratio in a case-cohort analysis. RESULTS: Over a median period of 25 months (IQR 14-43), a recurrence rate of 3% (95%CI 1.7-4.3) was observed, predominantly (13/21) following R0 resections with favourable histology. Endoscopic retreatment was feasible in 18 of 21 recurrences. The proportion of R0-cases where the safety margin in both horizontal (HM) and vertical (VM) margin exceeded 1 mm was similarly distributed in the recurrence and non-recurrence group, representing nearly 20% of cases. However, cases with HM less than 1 mm, despite VM greater than 1 mm, nearly doubled in the recurrence group (7.7% vs. 3.9%), and tripled when both margins were under 1 mm (23.1% vs. 7.7%). Despite this trend, statistical significance was not achieved (p = 0.05). In the overall cohort, the only independent risk factor significantly associated with local recurrence was the presence of residual tumor at the HM (HM1) or not assessable HM (HMx) (OR 16.5 (95%CI 4.4-61.7), and OR 11.7 (95%CI 1.1-124.1), respectively). CONCLUSIONS: While not common or typically challenging to manage, recurrence post-ESD warrants attention and justifies rigorous post-procedural surveillance, especially in patients with HM1, HMx, and probably also in those with R0 resections but narrow safety margin.

Intraoperative evaluation of surgical margins in breast cancer.

Achieving clear resection margins at the time of lumpectomy is essential for optimal patient outcomes. Margin status is traditionally determined by pathologic evaluation of the specimen and often is difficult or impossible for the surgeon to definitively know at the time of surgery, resulting in the need for re-operation to obtain clear surgical margins. Numerous techniques have been investigated to enhance the accuracy of intraoperative margin and are reviewed in this manuscript.

Unveiling Rarity: A Case Report of a Poorly Differentiated Synovial Sarcoma Mimicking a Plunging Ranula.

Synovial sarcomas are uncommon and highly aggressive sarcomas. Typically, they start in the soft tissues of the extremities, although they may develop in the head and neck region in rare cases. When they do, they usually present with localized symptoms in the affected area. Our patient is a 20-year-old man without a medical history who complained of a three-month history of submental swelling of the left side with a non-tender, palpable 5 cm mass. Initially believed to be a plunging ranula, the patient underwent transoral excision of the left submandibular soft tissue mass in the neck by the ear, nose, and throat (ENT) specialist. The pathological analysis of the mass confirmed the presence of a poorly differentiated synovial sarcoma. A postoperative neck imaging was performed, which showed a significant decrease in mass size compared to the previous imaging; however, the mass was still present. This is one of the few described cases of a poorly differentiated synovial sarcoma located on the floor of the mouth. Therefore, it highlights the importance of considering it as a possible differential diagnosis of head and neck pathologies.

Evaluation of margins during radical prostatectomy: confocal microscopy vs frozen section analysis.

OBJECTIVES: To test the performance of ex vivo fluorescence confocal microscopy (FCM; Vivascope 2500M-G4), as compared to intra-operative frozen section (IFS) analysis, to evaluate surgical margins during robot-assisted radical prostatectomy (RARP), with final pathology as the reference standard. METHODS: Overall, 54 margins in 45 patients treated with RARP were analysed with: (1) ex vivo FCM; (2) IFS analysis; and (3) final pathology. FCM margins were evaluated by two different pathologists (experienced [M.I.: 10 years] vs highly experienced [G.R.: >30 years]) as strongly negative, probably negative, doubtful, probably positive, or strongly positive. First, inter-observer agreement (Cohen's κ) between pathologists was tested. Second, we reported the sensitivity, specificity, positive predictive (PPV) and negative predictive value (NPV) of ex vivo FCM. Finally, agreement between ex vivo FCM and IFS analysis (Cohen's κ) was reported. For all analyses, four combinations of FCM results were evaluated. RESULTS: At ex vivo FCM, the inter-observer agreement between pathologists ranged from moderate (κ = 0.74) to almost perfect (κ = 0.90), according to the four categories of results. Indeed, at ex vivo FCM, the highly experienced pathologist reached the best balance between sensitivity (70.5%) specificity (91.8%), PPV (80.0%) and NPV (87.1%). Conversely, on IFS analysis, the sensitivity, specificity, PPV and NPV were, respectively, 88.2% vs 100% vs 100% vs 94.8%. The agreement between the ex vivo FCM and IFS analyses ranged from moderate (κ = 0.62) to strong (κ = 0.86), according to the four categories of results. CONCLUSION: Evaluation of prostate margins at ex vivo FCM appears to be feasible and reliable. The agreement between readers encourages its widespread use in daily practice. Nevertheless, as of today, the performance of FCM seems to be sub-par when compared to the established standard of care (IFS analysis).

Surgical outcomes and prognosis of HER2+ invasive breast cancer patients with a DCIS component treated with breast-conserving surgery after neoadjuvant systemic therapy.

INTRODUCTION: In up to 72 % of HER2+ invasive breast cancer (IBC), a ductal carcinoma in situ (DCIS) component is present. The presence of DCIS is associated with increased positive surgical margins after breast-conserving surgery (BCS). The aim of this study was to assess surgical margins, recurrence and survival in a nationwide cohort of HER2+ IBC with versus without a DCIS component, treated with neoadjuvant systemic therapy (NST) and BCS. MATERIALS AND METHODS: Women diagnosed with HER2+ IBC treated with NST and BCS, between 2010 and 2019, were selected from the Netherlands Cancer Registry and linked to the Dutch Nationwide Pathology Databank. Kaplan-Meier and Cox regression analyses were performed to determine locoregional recurrence rate (LRR) and overall survival (OS) and associated clinicopathological variables. Surgical outcomes and prognosis were compared between IBC only and IBC+DCIS. RESULTS: A total of 3056 patients were included: 1832 with IBC and 1224 with IBC+DCIS. Patients with IBC+DCIS had significantly more often positive surgical margins compared to IBC (12.8 % versus 4.9 %, p < 0.001). Five-year LRR was significantly higher in patients with IBC+DCIS compared to IBC (6.8 % versus 3.6 %, p < 0.001), but the presence of DCIS itself was not significantly associated with LRR after adjusting for confounders in multivariable analysis. Five-year OS did not differ between IBC+DCIS and IBC (94.9 % versus 95.7 %, p = 0.293). CONCLUSION: The presence of DCIS is associated with higher rates of positive surgical margins, but not with LRR and lower OS when adjusted for confounders. Further research is necessary to adequately select IBC+DCIS patients for BCS after NST.

Clinical Relevance of Resection Margins in Patients with Total Laryngectomy or Laryngopharyngectomy.

BACKGROUND: Laryngeal and hypopharyngeal cancer is complex and resection margins are therefore constrained. The aim of this study was to investigate the clinical relevance of resection margins in laryngeal and hypopharyngeal surgery. METHODS: A retrospective cohort study was performed for patients treated with a total laryngectomy (TL) or laryngopharyngectomy (TLP) for laryngeal or hypopharyngeal squamous cell carcinoma (LSCC and HSCC, respectively). Within the groups primary LSCC, recurrent LSCC, primary HSCC, and recurrent HSCC the relationship between the status of the resection margin according to the Royal Collage of Pathology and the recurrence and survival rates were investigated. RESULTS: Positive resection margins were found in 54% for primary LSCC, 29% for recurrent LSCC, 62% for primary HSCC, and 44% for recurrent HSCC. For primary and recurrent LSCC, there was a linear association between total recurrence and narrowing margins (p = 0.007 resp. p = 0.008). Multivariate survival analysis for primary and recurrent LSCC showed a significantly worse disease free and disease-specific survival in case of positive margins compared to clear margins. CONCLUSION: Similar survival rates were recorded for close and clear margins for primary and recurrent LSCC. This may suggest that a margin > 5 mm is not clinically relevant in terms of survival. Therefore, a margin of 1-5 mm should be accepted in certain subsites. Margins < 1 mm are related to significantly worse outcomes and should be avoided.

A New Proposal for Adequate Resection Margins in Larynx and Hypopharynx Tumor Surgery-Are the RCP Guidelines Feasible?

BACKGROUND: Resection margins are an important prognostic factor for patients with head and neck cancer. In general, for head and neck surgery, a margin >5 mm is advised by the Royal College of Pathologists. However, this cannot always be achieved during laryngeal and hypopharyngeal surgery. The aim of this study is to identify the resection surfaces and measure the maximum feasible margins per subsite. The clinical relevance of these maximum feasible resection margins were analyzed in this descriptive anatomical study. METHODS: head and neck surgeons and a pathologist from the Erasmus MC performed a total laryngectomy and laryngopharyngectomy on a head and neck specimen specifically available for research. RESULTS: For a total laryngectomy, resection margins >5 mm were not feasible for the ventral and dorsal resection surface. For a total laryngopharyngectomy, resection margins >5 mm were not feasible for the ventral, dorsal and lateral resection surface. CONCLUSION: Clear resection margins, defined as a margin >5 mm, are not always feasible in laryngeal and hypopharyngeal surgery, due to the anatomy of the larynx and tumor location. However, striving for a maximum feasible margin is still the main goal. We propose a new guideline for maximum feasible but adequate resection margins in larynx and hypopharynx tumor surgery.

Architectural dysplasia in surgical margins and the risk of local relapse in oral cancer.

BACKGROUND: A major challenge in the clinical management of oral cavity squamous cell carcinoma is local relapse. Even when surgical margins are tumor-free, local relapses occur frequently, and relapse prediction by histology remains suboptimal. In leukoplakia, an oral potentially malignant disorder, the presence of architectural dysplasia is a critical risk factor for malignant transformation. This study aimed to investigate whether the presence of architectural dysplasia in oral cavity squamous cell carcinoma surgical margins is a risk factor for local relapse. METHODS: Hematoxylin and eosin-stained slides of resection margins from a consecutive cohort of surgically treated patients diagnosed with stage I-IV oral cavity squamous cell carcinoma between 2008 and 2014 were assessed for the presence of architectural dysplasia (N = 311). Five-year local relapse-free survival rates of oral cavity squamous cell carcinoma with architectural dysplasia were compared to those of oral cavity squamous cell carcinoma without architectural dysplasia. RESULTS: In total, 92 of 311 (29.6%) of oral cavity squamous cell carcinoma displayed architectural dysplasia in the margins. The presence of architectural dysplasia was associated with higher patient age, female sex, less pack years, lower cT-stage, and a cohesive tumor growth pattern. In oral cavity squamous cell carcinomas with architectural dysplasia, postoperative (chemo)radiotherapy was less often indicated compared with oral cavity squamous cell carcinoma without architectural dysplasia (19.5% vs. 36.1%, p = 0.009). Five-year local relapse-free survival was significantly lower in oral cavity squamous cell carcinoma with architectural dysplasia than in oral cavity squamous cell carcinoma without architectural dysplasia (83.1% vs. 94.9%, p = 0.017). CONCLUSIONS: Oral cavity squamous cell carcinoma arising in the background of architectural dysplasia displays relatively favorable clinical and histopathological characteristics. Nonetheless, the presence of architectural dysplasia in oral cavity squamous cell carcinoma surgical margins is associated with a higher risk of local relapse, indicating its clinical relevance.

Artificial Intelligence Improves the Ability of Physicians to Identify Prostate Cancer Extent.

PURPOSE: Defining prostate cancer contours is a complex task, undermining the efficacy of interventions such as focal therapy. A multireader multicase study compared physicians' performance using artificial intelligence (AI) vs standard-of-care methods for tumor delineation. MATERIALS AND METHODS: Cases were interpreted by 7 urologists and 3 radiologists from 5 institutions with 2 to 23 years of experience. Each reader evaluated 50 prostatectomy cases retrospectively eligible for focal therapy. Each case included a T2-weighted MRI, contours of the prostate and region(s) of interest suspicious for cancer, and a biopsy report. First, readers defined cancer contours cognitively, manually delineating tumor boundaries to encapsulate all clinically significant disease. Then, after ≥ 4 weeks, readers contoured the same cases using AI software. Using tumor boundaries on whole-mount histopathology slides as ground truth, AI-assisted, cognitively-defined, and hemigland cancer contours were evaluated. Primary outcome measures were the accuracy and negative margin rate of cancer contours. All statistical analyses were performed using generalized estimating equations. RESULTS: The balanced accuracy (mean of voxel-wise sensitivity and specificity) of AI-assisted cancer contours (84.7%) was superior to cognitively-defined (67.2%) and hemigland contours (75.9%; P < .0001). Cognitively-defined cancer contours systematically underestimated cancer extent, with a negative margin rate of 1.6% compared to 72.8% for AI-assisted cancer contours (P < .0001). CONCLUSIONS: AI-assisted cancer contours reduce underestimation of prostate cancer extent, significantly improving contouring accuracy and negative margin rate achieved by physicians. This technology can potentially improve outcomes, as accurate contouring informs patient management strategy and underpins the oncologic efficacy of treatment.

Association of Surgical Approaches and Outcomes in Total Mesorectal Excision and Margin Status for Rectal Cancer.

INTRODUCTION: Despite being a key metric with a significant correlation with the outcomes of patients with rectal cancer, the optimal surgical approach for total mesorectal excision (TME) has not yet been identified. The aim of this study was to assess the association of the surgical approach on the quality of TME and surgical margins and to characterize the surgical and long-term oncologic outcomes in patients undergoing robotic, laparoscopic, and open TME for rectal cancer. METHODS: Patients with primary, nonmetastatic rectal adenocarcinoma who underwent either lower anterior resection or abdominoperineal resection via robotic (Rob), laparoscopic (Lap), or open approaches were selected from the US Rectal Cancer Consortium database (2007-2017). Quasi-Poisson regression analysis with backward selection was used to investigate the relationship between the surgical approach and outcomes of interest. RESULTS: Among the 664 patients included in the study, the distribution of surgical approaches was as follows: 351 (52.9%) underwent TME via the open approach, 159 (23.9%) via the robotic approach, and 154 (23.2%) via the laparoscopic approach. There were no significant differences in baseline demographics among the three cohorts. The laparoscopic cohort had fewer patients with low rectal cancer (<6 cm from the anal verge) than the robotic and open cohorts (Lap 28.6% versus Rob 59.1% versus Open 45.6%, P = 0.015). Patients who underwent Rob and Lap TME had lower intraoperative blood loss compared with the Open approach (Rob 200 mL [Q1, Q3: 100.0, 300.0] versus Lap 150 mL [Q1, Q3: 75.0, 250.0] versus Open 300 mL [Q1, Q3: 150.0, 600.0], P < 0.001). There was no difference in the operative time (Rob 243 min [Q1, Q3: 203.8, 300.2] versus Lap 241 min [Q1, Q3: 186, 336] versus Open 226 min [Q1, Q3: 178, 315.8], P = 0.309) between the three approaches. Postoperative length of stay was shorter with robotic and laparoscopic approach compared to open approach (Rob 5.0 d [Q1, Q3: 4, 8.2] versus Lap 5 d [Q1, Q3: 4, 8] versus Open 7.0 d [Q1, Q3: 5, 9], P < 0.001). There was no statistically significant difference in the quality of TME between the robotic, laparoscopic, and open approaches (79.2%, 64.9%, and 64.7%, respectively; P = 0.46). The margin positivity rate, a composite of circumferential margin and distal margin, was higher with the robotic and open approaches than with the laparoscopic approach (Rob 8.2% versus Open 6.6% versus Lap 1.9%, P = 0.17), Rob versus Lap (odds ratio 0.21; 95% confidence interval 0.05, 0.83) and Rob versus Open (odds ratio 0.5; 95% confidence interval 0.22, 1.12). There was no difference in long-term survival, including overall survival and recurrence-free survival, between patients who underwent robotic, laparoscopic, or open TME (Figure 1). CONCLUSIONS: In patients undergoing surgery with curative intent for rectal cancer, we did not observe a difference in the quality of TME between the robotic, laparoscopic, or open approaches. Robotic and open TME compared to laparoscopic TME were associated with higher margin positivity rates in our study. This was likely due to the higher percentage of low rectal cancers in the robotic and open cohorts. We also reported no significant differences in overall survival and recurrence-free survival between the aforementioned surgical techniques.

Beyond the surface: A comparative study of intraoral scanners in subgingival configuration scanning.

OBJECTIVES: This study conducted a comprehensive comparative analysis of three intraoral scanners (CEREC Primescan, TRIOS, CEREC Omnicam) and a lab scanner (inEosX5) assessing their precision in simulating subgingival tooth preparations. METHODS: Utilizing a dental simulation mannequin with a 3D-printed resin structure, 100 structures with depths ranging from 0.5 to 4.0 mm were created within a square mimicking a rectangular tank surface. Four scanner groups (A-D) and five subgroups were established. Two digitization methods, a customized parallelometer and an intraoral simulation, were applied, ensuring a standardized scanning sequence. Trueness was evaluated by comparing CAD-calculated surface areas with actual dimensions, and qualitative trueness analysis was conducted using MeshLab. Surface areas were computed using the formula SA = 2lw + 2lh + 2wh. Statistical analyses, including Pearson's correlation coefficient, Kolmogorov-Smirnoff and Levene's tests, three-way ANOVA, and paired sample t-tests, elucidated relationships and differences (a=0.05). RESULTS: A robust correlation (r = 0.850, p < 0.001) between intraoral scanner choice and scanned area depth was found. Inverse correlations were noted for experimental methods. Three-way ANOVA demonstrated significant scanner-depth interaction (F(12,760) = 760.801, p < 0.001). SIGNIFICANCE: Emphasizing high-resolution sensors and advanced technologies, the study underscores the optimal choice for subgingival digitization, acknowledging variations among scanners.

Margin status, adjuvant treatment and recurrence in buccal cancer.

OBJECTIVE: To assess the prognostic importance of margin in resected buccal cancer within a framework of risk factor-driven postoperative adjuvant treatment. MATERIALS AND METHODS: Consecutive, treatment naïve patients undergoing primary surgical treatment for buccal cancer. Margin was defined as clear (≥5 mm), close (1-4 mm) and involved (<1 mm). Main outcome was association of margin with local recurrence free survival (LRFS). Subgroup analysis of close margin was performed according to receipt or no receipt of adjuvant treatment. A numerical margin cut-off in mm that could independently predict LRFS was sought to be identified. RESULTS: Of the 167 patients included, the frequency of clear, close and involved margins was 50 (30 %), 78 (47 %) and 39 (23 %) respectively, among whom 52 %, 44 % and 98 % received postoperative adjuvant treatment respectively. Clear and close margins had similar 3-year LRFS (89 % and 96 % respectively), while involved margin had worse 3-year LRFS at 65 %. Involved margin was confirmed to be strongly and independently associated with worse LRFS. Within close margin, receipt and no receipt of adjuvant treatment had similar 3-year LRFS (92 % and 100 % respectively). A margin cut-off of 2 mm was identified at or above which LRFS approximated that of clear margin. CONCLUSIONS: This single center cohort study of patients with resected buccal cancer suggests that close margin is distinct from and has a better LRFS than involved margin. A subset of close margin, with margin size ≥ 2 mm and no other adverse features, might be spared adjuvant treatment without compromising outcomes.

Deep carbon recycling viewed from global plate tectonics.

Plate tectonics plays an essential role in the redistribution of life-essential volatile elements between Earth's interior and surface, whereby our planet has been well tuned to maintain enduring habitability over much of its history. Here we present an overview of deep carbon recycling in the regime of modern plate tectonics, with a special focus on convergent plate margins for assessing global carbon mass balance. The up-to-date flux compilation implies an approximate balance between deep carbon outflux and subduction carbon influx within uncertainty but remarkably limited return of carbon to convecting mantle. If correct, carbon would gradually accumulate in the lithosphere over time by (i) massive subsurface carbon storage occurring primarily in continental lithosphere from convergent margins to continental interior and (ii) persistent surface carbon sinks to seafloors sustained by high-flux deep CO2 emissions to the atmosphere. Further assessment of global carbon mass balance requires updates on fluxes of subduction-driven carbon recycling paths and reduction in uncertainty of deep carbon outflux. From a global plate tectonics point of view, we particularly emphasize that continental reworking is an important mechanism for remobilizing geologically sequestered carbon in continental crust and sub-continental lithospheric mantle. In light of recent advances, future research is suggested to focus on a better understanding of the reservoirs, fluxes, mechanisms, and climatic effects of deep carbon recycling following an integrated methodology of observation, experiment, and numerical modeling, with the aim of decoding the self-regulating Earth system and its habitability from the deep carbon recycling perspective.

Breast Conservation Therapy for Primary Squamous Cell Carcinoma of the Breast in an Elderly Woman: A Case Report.

This case report details a rare instance of primary squamous cell carcinoma (PSCC) of the breast in an octogenarian, emphasizing the unique diagnostic and treatment challenges posed by this malignancy in an elderly patient and adding to the scientific literature on PSCC managed with breast conservation therapy (BCT). An 80-year-old woman with medical comorbidities presented with a focal asymmetry in the right breast's retroareolar plane, detected during routine screening mammography. Diagnostic evaluations raised high suspicion for malignancy, confirmed as PSCC by ultrasound-guided biopsy. Histopathological analysis showed atypical keratinizing squamous epithelial nests and cysts. The patient underwent lumpectomy and re-excision of close surgical margins with a sentinel lymph node biopsy, which showed well-differentiated invasive squamous cell carcinoma with no residual carcinoma or nodal involvement. She was treated with adjuvant hypofractionated radiation therapy, experiencing minimal side effects. This case highlights the importance of considering individualized, nuanced approaches to adjuvant therapies in the treatment of PSCC in older patients. It demonstrates that BCT, coupled with carefully selected adjuvant therapy, can be a successful treatment strategy for PSCC in the elderly, contributing valuable insights into the management of this rare condition.

Intraoperative Ultrasound for the Management of Oral Tongue Cancer: a Systematic Review and Meta-Analysis.

Objective: To evaluate for correlation between intraoperative ultrasound (IOUS)-measured tumor thickness (TT) (uTT) and histopathological TT (hTT), and to compare IOUS-assisted resection with conventional resection in patients with oral tongue cancers. Data Sources: Ovid MEDLINE (1946-2023), Embase.com (1947-2023), and Web of Science (All Databases 1900-2023). Review Methods: Inclusion criteria were the use of IOUS for the management of oral tongue cancer. Studies that did not report quantitative data were excluded. Additionally, studies that were not contributory to meta-analysis, or a narrative analysis of pooled results were excluded. Selection was carried out by 2 reviewers. A total of 2417 studies were initially identified, with 12 ultimately being included in this review, and 7 included in the meta-analysis. Data were extracted by 2 investigators and were pooled using a random-effects model. Results: Our meta-analysis reveals a pooled correlation coefficient of 0.92 (95% confidence interval: 0.80-0.96) for studies comparing uTT to hTT. Studies comparing IOUS-assisted resection to conventional resection found IOUS-assisted resection yielded wider nearest margins in all studies reporting this outcome. Conclusion: IOUS reliably measures TT, similarly to that of histopathology measurement. IOUS-assisted resection, which allows the surgeon to view the deep extent of tumor invasion, may increase closest radial margin distance compared to conventional resection. IOUS-assisted resection may represent a more reliable approach to achieving clear margins than conventional resection.