Merchea, Amit

Abstract Background Presacral tumours are rare, heterogeneous lesions. Historical classification systems for presacral tumours have provided a valuable framework, but were based on limited available data. This study aimed to develop a contemporary classification aligned with current tumour entities and clinical practice. Methods A prospectively registered systematic review of surgically managed presacral tumours published from 1975 to 2025 was combined with a retrospective multisite institutional surgical pathology review from 1986 to 2025. Pathological descriptors were extracted, cross-referenced, harmonized to current terminology, and organized through multidisciplinary expert review to obtain a new classification. Results The systematic review identified 5997 records, of which 203 studies met the inclusion criteria and contributed 181 pathological terms after generic and unclassifiable diagnoses were removed. Review of 3606 pathology reports identified 19 additional terms, bringing the total to 200 pathological terms. After harmonization to current terminology and exclusion of non-neoplastic processes, a contemporary classification was developed using biological descriptors: developmental versus acquired origin; tissue lineage (neurogenic, osseous/haematopoietic, soft tissue, or miscellaneous); and tumour behaviour (benign, locally recurrent without metastatic potential, locally recurrent with low metastatic potential, malignant non-sarcoma, or malignant sarcoma). Conclusion The Mayo Clinic classification of presacral tumours updates historical systems by reflecting the broader, more modern spectrum of neoplasms and distinguishing lesions by lineage and biological behaviour. It may improve diagnostic clarity, communication, and selection of appropriate observation, multidisciplinary assessment, and treatment pathways.

BACKGROUND: Surgeons and ostomy nurses receive a high volume of stoma photos from patients. OBJECTIVE: This study aimed to develop and validate an automated and scalable artificial intelligence pipeline for identification and triage of patient-submitted intestinal ostomy photos. DESIGN: Retrospective derivation and validation study with stakeholder engagement to guide model design. Clinical teams reviewed photos in duplicate and categorized them into: (a) obstructed view, (b) healthy stoma, (c) suitable for conservative management, or (d) requiring in-person review. Pre-trained neural networks including MobileNetV4, ResNet50, ViT and CLIP-ViT were fine-tuned with 5-fold cross-validation. SETTINGS: Nine Mayo Clinic hospitals (2019–2022). PATIENTS: Adult patients (≥18 years) undergoing surgery who submitted images within 30 days after surgery. MAIN OUTCOME MEASURES: Model performance was evaluated with area under the receiver operator curve, precision, recall, and F1-scores. RESULTS: In this study, 538 photos of abdominal ostomies were sent in by 191 patients (median age 52 years, IQR 40–63; 60.4% female). Expert consensus triaged 236 (43.9%) photos as having an obstructed view, 30 (5.6%) as healthy, 177 (32.9%) for conservative management, and 95 (17.7%) for in-person review. All models achieved area under the receiver operator curve >0.97 for identifying stomas. The CLIP-ViT model performed best at triage (macro- area under the receiver operator curve 0.94 ± 0.06; F1 0.77 ± 0.10). End-to-end detection and triage using CLIP-ViT achieved area under the receiver operator curve of 0.99 ± 0.01, precision of 0.87 ± 0.08, recall of 0.93 ± 0.04, and F1 of 0.89 ± 0.07. Attention maps showed that models focused on stomas to determine classification. LIMITATIONS: Low sample size and lack of prospective validation. CONCLUSIONS: A vision language model pipeline accurately detected and triaged patient-submitted ostomy photos. Prospective evaluation is now needed to support integration into multidisciplinary digital workflows. See Video Abstract .

Background: The comparative effectiveness of robotic-assisted versus conventional minimally invasive (“straight stick”) approaches across multiple solid organ malignancies remains incompletely defined, limiting evidence-based operative platform selection. Study Design: Patients undergoing minimally invasive primary tumor resection for 17 solid organ cancers were identified in the National Cancer Database (2010–2022) and stratified by robotic-assisted versus straight stick approach. The primary endpoint was conversion to open surgery. Secondary endpoints included short-term outcomes and oncologic/technical metrics. Multivariable logistic and negative binomial regression models were used to estimate adjusted associations. Results: Among 2,258,360 patients, 1,339,482 (59.3%) underwent robotic-assisted resection. Robotic surgery was associated with lower adjusted conversion rates compared with straight stick approaches (6.1% vs 13.6%, p<0.001), a finding consistent across all organ sites. Robotic approaches yielded approximately one additional lymph node on average after adjustment. Length of stay, 90-day mortality, and negative margin rates were overall similar between groups, with variation by disease site. Conclusions: In this large national cohort, robotic-assisted resection for solid organ malignancies was more frequently utilized and associated with lower conversion rates and modestly higher lymph node yield compared with straight stick approaches. These findings support consideration of robotic platforms to reduce conversion risk, although equivalence in other short-term outcomes and potential residual confounding warrant cautious interpretation.

Abstract Background Presacral tumours are rare and heterogeneous lesions arising within a complex anatomical space, resulting in variability in diagnosis and management. Increasing incidental detection and evolving surgical and oncological strategies have highlighted the need for contemporary guidance. The aim of this study was to establish an international expert consensus on the optimal diagnosis and management of presacral tumours. Methods An international panel of colorectal surgeons from high-volume units was convened. Evidence- and practice-based statements were developed after domain-based literature reviews and refined through five online and two in-person meetings. Consensus was achieved using a modified Delphi process with anonymous voting. Results In total, 16 colorectal surgeons participated in the study. Ten domains were identified resulting in the development of 22 statements based on expert opinion and retrospective studies. After two rounds, unanimous (100%) agreement was achieved for all statements. High-resolution MRI with structured synoptic reporting is endorsed as central to risk stratification. Selective image-guided transperineal or parasacral biopsy is recommended for high-risk lesions where histology would alter management. Complete surgical resection is defined as the operative goal, with approach tailored to tumour biology and anatomy; minimally invasive surgery is considered appropriate in selected cases. Non-operative surveillance is supported for carefully selected asymptomatic, low-risk cystic lesions. Postoperative surveillance is recommended in a risk-adapted manner according to histopathology and margin status. Conclusion This international consensus provides a pragmatic, risk-stratified framework for the multidisciplinary diagnosis and management of presacral tumours. These recommendations aim to reduce practice variation, support decision-making in specialized centres, and inform future prospective collaborative research.

Abstract Peritoneal Carcinomatosis (PC) is a metastatic cancer of the lining of the abdominal cavity, most often originating from the gastrointestinal or gynecological tracts. PC occurs in approximately 20% of colorectal cancer and 60% of ovarian cancer cases, with estimated 5-year survival rates as low as 6%. Pressurized intraperitoneal aerosolized chemotherapy (PIPAC) is a locoregional drug delivery modality administered via a minimally invasive laparoscopic approach. PIPAC shows promise in the treatment of peritoneal metastasis in early trials on colorectal cancer (CRC) or appendiceal cancer (AC) in patients who cannot undergo cytoreductive surgery. The spatial organization of the tumor microenvironment (TME) and the complex cellular interactions within profoundly shape biology and treatment response. Spatial transcriptomics offers an opportunity to characterize TME heterogeneity in its native architecture, allowing the identification of biomarkers, interactions, and gene expression programs as well as resistance mechanisms and new potential targets. We performed image-based spatial transcriptomic profiling of 152 tissue samples, including 50 pre-treatment and 65 post-treatment metastatic tumors and 17 pre-treatment and 20 post-treatment tumor-adjacent normal tissue samples from 19 patients who participated in a Phase I trial on Oxaliplatin PIPAC. Through a comprehensive characterization of transcriptional profiles of a total of 1,249,711 cells, as well as cellular neighborhood and ligand-receptor interactions, we describe the heterogeneity of PC in its spatial context. We have further characterized treatment-driven changes in pre- and post-treatment tumors of a subset of 7 patients who underwent PIPAC with mitomycin IP. Through cell-based niche and proximity analyses, we identify distinct shifts in the composition and architecture of treated tumors. Most notably, treatment resulted in an 87% decrease in the number of malignant cells, as well as an expansion of the plasma-barrier niche and an increased number of immune infiltrates. Further analysis revealed distinct differences in the abundance of specific cancer-associated fibroblast and immune subsets, demonstrating changes in TME architecture. Overall, our results provide an invaluable characterization of PC in CRC and AC, garnering new insight into their architecture, cellular composition, and cell-cell interactions at baseline and in response to regional chemotherapy. Further analyses and follow-up studies can identify and validate new, actionable biomarkers to target these hard-to-treat tumors. Citation Format: Heini Maaret Natri, Arianna L. Williams-Katek, Muhammad Talha Waheed, Tiana Li, Marwan Fakih, Mingye Feng, Amit Merchea, Sue Chang, Richard L. Whelan, Danielle Deperalta, Thanh H. Dellinger, Nicholas Banovich, Mustafa Raoof. Spatial transcriptomic profiling of peritoneal metastases identifies multicellular programs in patient tumors undergoing pressurized intraperitoneal aerosol chemotherapy (PIPAC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 3958.

BACKGROUND: Patients with locally advanced rectal cancer face substantial costs related to multimodal therapy. However, the extent of this burden is poorly characterized. OBJECTIVE: To characterize the prevalence and predictors of patient-reported financial toxicity after treatment for locally advanced rectal cancer. DESIGN: Multicenter retrospective cohort study with a cross-sectional survey administered to assess patients’ financial concerns as well as clinicodemographic data. SETTING: Three high-volume tertiary academic centers. PATIENTS: Patients who completed treatment for pathological stage II to III rectal adenocarcinoma between 2000 and 2019 and were alive. MAIN OUTCOME MEASURES: Patient-reported financial toxicity and risk factors associated with financial toxicity. RESULTS: A total of 523 patients were identified, 190 (36.3%) responded to the survey, and 2 were excluded for incomplete surveys. Of the responders, 163 (86.7%) were identified as having financial toxicity related to their cancer diagnosis, and most (96.8%) had insurance. Patients with financial toxicity were less likely to have fully paid medical leave (39.8% vs 75%; p = 0.03) compared to patients without financial toxicity. They also reported increased difficulty paying bills ( p < 0.001) and decreased monthly household income ( p < 0.001) due to their diagnosis. Furthermore, these patients reported increased difficulty paying for transportation to medical appointments ( p = 0.002) and were less likely to be completely satisfied with their insurance coverage ( p = 0.003). Feeling well informed regarding treatment-related costs was associated with decreased odds of financial toxicity (OR 0.14; 95% CI, 0.02–0.78; p = 0.02), whereas taking unpaid leave for treatment was associated with increased odds of financial toxicity (OR 4.71; 95% CI, 1.36–16.34; p = 0.01). LIMITATIONS: Cross-sectional design and moderate response rate may introduce selection and recall bias. CONCLUSIONS: Patients undergoing treatment for locally advanced rectal cancer, including those insured, are at risk for financial toxicity due to direct and indirect costs. Effective communication between these patients and physicians regarding the economic implications of treatment is essential to reducing financial toxicity. See Video Abstract . TOXICIDAD FINANCIERA TRAS EL TRATAMIENTO DEL CÁNCER RECTAL LOCALMENTE AVANZADO ANTECEDENTES: Los pacientes con cáncer de recto localmente avanzado enfrentan costos sustanciales relacionados con la terapia multimodal. Sin embargo, la magnitud de esta carga está poco caracterizada. OBJETIVO: Caracterizar la prevalencia y los predictores de la toxicidad financiera reportada por los pacientes después del tratamiento para el cáncer de recto localmente avanzado. DISEÑO: Estudio de cohorte retrospectivo multicéntrico con una encuesta transversal para evaluar las preocupaciones financieras de los pacientes, así como datos clínico-demográficos. ESCENARIO: Tres centros académicos terciarios de alto volumen. PACIENTES: Pacientes que completaron el tratamiento para el adenocarcinoma de recto en estadio patológico II-III entre 2000 y 2019 y estaban vivos. PRINCIPALES MEDIDAS DE RESULTADOS: Toxicidad financiera reportada por los pacientes y factores de riesgo asociados con la toxicidad financiera. RESULTADOS: Se identificó a un total de 523 pacientes, 190 (36,3%) respondieron a la encuesta y 2 fueron excluidos por encuestas incompletas. De los encuestados, 163 (86,7 %) presentaron toxicidad financiera relacionada con su diagnóstico de cáncer, y la mayoría (96,8 %) contaba con seguro médico. Los pacientes con toxicidad financiera tuvieron menos probabilidades de tener licencia médica con goce de sueldo completo (39,8 % frente a 75 %; p = 0,03) en comparación con los pacientes sin toxicidad financiera. También informaron mayor dificultad para pagar facturas ( p < 0,001) y una disminución de los ingresos familiares mensuales ( p < 0,001) debido a su diagnóstico. Además, estos pacientes informaron mayor dificultad para pagar el transporte a las citas médicas ( p = 0,002) y menor probabilidad de estar completamente satisfechos con su cobertura médica ( p = 0,003). Sentirse bien informado sobre los costos relacionados con el tratamiento se asoció con una menor probabilidad de toxicidad financiera (OR: 0,14; IC del 95 %: 0,02-0,78; p = 0,02), mientras que tomar una licencia sin sueldo para el tratamiento se asoció con una mayor probabilidad de toxicidad financiera (OR: 4,71; IC del 95 %: 1,36-16,34; p = 0,01). LIMITACIONES: El diseño transversal y la tasa de respuesta moderada pueden introducir sesgos de selección y de recuerdo. CONCLUSIONES: Los pacientes en tratamiento para el cáncer de recto localmente avanzado, incluidos los asegurados, corren el riesgo de sufrir toxicidad financiera debido a los costos directos e indirectos. Una comunicación eficaz entre estos pacientes y los médicos sobre las implicaciones económicas del tratamiento es esencial para reducir la toxicidad financiera. ( AI-generated translation )

Abstract Aim Rectal prolapse is a full‐thickness intussusception of the rectum beyond the anal canal. It is often mistaken for other anorectal pathologies, leading to inaccurate referrals to colorectal surgeons and inappropriate management. However, the frequency of misdiagnosis is not well characterized. We aimed to assess the diagnostic accuracy of rectal prolapse referrals to three tertiary medical centres. Methods This is a retrospective study of patients referred for rectal prolapse to colorectal surgeons at the Mayo Clinic in Rochester, Jacksonville, and Phoenix from 2020 to 2024. The primary outcome is the accuracy of rectal prolapse diagnosis. The secondary outcomes are factors that correlate with diagnostic accuracy. Results Rectal prolapse was inaccurately diagnosed in 38.7% (186/480) of patients. Among misdiagnosed patients, the correct diagnosis was haemorrhoids (68.0%, n = 134), pelvic floor dysfunction (24.3%, n = 48) and rectocele (18.7%, n = 37). A diagnosis of rectal cancer was found in 3 patients (1.5%). The most common presenting symptoms were protrusion (66.3%, n = 345) and bleeding (33.6%, n = 175). Among the referring physicians, only 50.5% ( n = 227) performed an anorectal examination. Overall, there was significant variability in diagnostic accuracy across different specialties, with the highest accuracy from colorectal practices (84.0%) and the lowest from urologists (50.0%). Internal medicine physicians had a lower diagnostic accuracy with anorectal examination than without, though it did not reach statistical significance (44.0% vs. 59.5%, p = 0.2). Conclusion Over one‐third of rectal prolapse referrals were incorrectly diagnosed. This study highlights the opportunity for further training of referring providers on anorectal pathologies to improve diagnostic accuracy which could reduce treatment delays and optimize clinical outcomes.

BACKGROUND: Stoma-free survival represents a key quality-of-life outcome after surgery for locally advanced rectal cancer. Despite advances in neoadjuvant and surgical management, up to 30% of patients ultimately require a permanent fecal diversion. OBJECTIVE: To evaluate stoma-free survival and identify factors associated with permanent stoma formation in patients with locally advanced rectal cancer undergoing coloanal anastomosis. DESIGN: Retrospective cohort study. SETTINGS: Single tertiary referral center (2017–2021). PATIENTS: A total of 126 patients with clinical stage II and III rectal adenocarcinoma who received neoadjuvant therapy and underwent curative-intent resection with coloanal anastomosis were included. INTERVENTION: Curative-intent resection with coloanal anastomosis. MAIN OUTCOME MEASURES: The primary outcome was stoma-free survival. Secondary analyses examined factors associated with permanent fecal diversion. RESULTS: The medical records of 126 patients were analyzed, comprising 62.5% men, with a mean age of 54 ± 10 years and a median BMI of 27.7 (interquartile range 24.5–31.4). At a median follow-up of 53.0 months, the 5-year stoma-free survival rate was 88.9%. Univariate Cox regression analysis showed that BMI ≥35 (HR 3.80; 95% CI, 1.04–13.91, p = 0.044) and handsewn coloanal anastomosis with mucosectomy compared to stapled coloanal anastomosis without mucosectomy (HR 5.58; 95% CI, 1.71–18.14, p = 0.004), as well as local recurrence (HR 6.51; 95% CI, 1.44–29.46), were associated with worse stoma-free survival. The 30-day major morbidity rate was 7.9% after the index surgery. Sixteen patients required permanent fecal diversion due to bowel dysfunction (n = 11), disease recurrence (n = 4), or bowel obstruction (n = 1). LIMITATIONS: Retrospective, single-institution design with limited generalizability. CONCLUSIONS: Coloanal anastomosis in the era of total neoadjuvant therapy resulted in favorable 5-year stoma-free survival. BMI ≥35, handsewn coloanal anastomosis with mucosectomy, and local recurrence were associated with worse stoma-free survival. See Video Abstract . SUPERVIVENCIA SIN ESTOMA TRAS UNA RESECCIÓN ANTERIOR BAJA CON ANASTOMOSIS COLOANAL PARA EL CÁNCER RECTAL EN ESTADIO II-III ANTECEDENTES: La supervivencia sin estoma representa un resultado clave para la calidad de vida tras la cirugía de cáncer rectal localmente avanzado. A pesar de los avances en el tratamiento neoadyuvante y quirúrgico, hasta un 30 % de los pacientes requieren finalmente una derivación fecal permanente. OBJETIVO: Evaluar la supervivencia sin estoma e identificar los factores asociados con la formación de un estoma permanente en pacientes con cáncer rectal localmente avanzado sometidos a anastomosis coloanal. DISEÑO: Estudio de cohorte retrospectivo. ENTORNO: Centro terciario de referencia único, 2017-2021. PACIENTES: Se incluyó a un total de 126 pacientes con adenocarcinoma rectal en estadio clínico II-III que recibieron terapia neoadyuvante y se sometieron a una resección con intención curativa con anastomosis coloanal. INTERVENCIÓN: Resección con intención curativa con anastomosis coloanal. PRINCIPALES MEDIDAS DE RESULTADO: El resultado principal fue la supervivencia sin estoma. Los análisis secundarios examinaron los factores asociados con la derivación fecal permanente. RESULTADOS: Se analizaron 126 pacientes, de los cuales el 62,5 % eran hombres, con una edad media de 54 ± 10 años y un índice de masa corporal medio de 27,7 kg/m 2 (rango intercuartílico: 24,5-31,4 kg/m 2 ). Con una mediana de seguimiento de 53,0 meses, la tasa de supervivencia sin estoma a 5 años fue del 88,9 %. El análisis de regresión de Cox univariante mostró que el índice de masa corporal ≥ 35 kg/m 2 (razón de riesgo = 3,80, intervalo de confianza del 95 %: 1,04-13,91, p = 0,044) y la anastomosis coloanal cosida a mano con mucosectomía, en comparación con la anastomosis coloanal grapada sin mucosectomía (razón de riesgo = 5,58, intervalo de confianza del 95 %: 1,71-18,14, p = 0,004), así como la recurrencia local (razón de riesgo = 6,51, intervalo de confianza del 95 %: 1,44-29,46) se asociaron con una peor supervivencia sin estoma. La tasa de morbilidad grave a los 30 días fue del 7,9 % tras la cirugía índice. Dieciséis pacientes requirieron una derivación fecal permanente debido a disfunción intestinal (n = 11), recurrencia de la enfermedad (n = 4) u obstrucción intestinal (n = 1). LIMITACIONES: Diseño retrospectivo, de una sola institución, con una generalización limitada. CONCLUSIONES: La anastomosis coloanal en la era de la terapia neoadyuvante total dio lugar a una supervivencia sin estoma favorable a los 5 años. El índice de masa corporal ≥ 35 kg/m2, la anastomosis coloanal cosida a mano con mucosectomía y la recurrencia local se asociaron con una peor supervivencia sin estoma. (AI-generated translation )

ABSTRACT Background The use of pressurized intraperitoneal aerosol chemotherapy (PIPAC) is becoming more frequent for patients with unresectable peritoneal metastases. This systematic review explores the indications, protocols, feasibility, safety, oncological outcomes, patient reported outcomes and quality of life outcomes for patients being treated with PIPAC. Methods A review of PubMed, Embase and the Cochrane Library was undertaken to identify studies pertaining to patients undergoing treatment with PIPAC. Clinicopathological characteristics, treatment protocols, safety data, treatment response data and outcome data were extracted from relevant studies and included in the analysis. Results Data from 1980 patients undergoing 4454 PIPAC procedures for peritoneal metastases from a range of primary cancers was extracted. The treatment protocols identified were relatively homogenous across all studies. Grade 3/4 complications, grade 3/4 toxicity and procedure related mortality occurred infrequently. At least partial histological response was seen in 61.8% of patients. Overall survival for studies presenting data for mixed primary tumors ranged from 8 to 25 months. Quality of life and function were relatively stable throughout treatment. Conclusions PIPAC is a safe and feasible treatment option for patients with peritoneal metastases. Ongoing studies are required to evaluate how it compares to best option standard of care chemotherapy.

Despite European colorectal liver metastases (CRLM) transplant trials having been performed entirely using deceased donor liver transplant (DDLT), there has been speculation about whether similar results can be achieved in the United States, given the lack of MELD score prioritization. A formal transplant protocol for unresectable CRLM was implemented in our center at the start of 2022 with the plan to utilize DDLT. Between 2022 and 2025, 86 patients with CRLM were referred to our program, and 19 patients underwent a formal transplant evaluation. Median time from listing until transplant was 31 days (range 3–115 d). Median allocation MELD was 8 (range 6–15). The donor livers were from DCDs, older donors, or National Share livers, which had been declined by all other centers. All but 2 of the cases underwent advanced perfusion. There were no cases of primary nonfunction, postreperfusion syndrome, acute kidney injury, hepatic artery thrombosis, or ischemic cholangiopathy. The length of stay for the median posttransplant was 5 days. Graft and patient survival were 100% at the time of maximal follow-up. Recurrence developed in 3 recipients (25.0%), 1 of whom was treated and has no evidence of disease. These findings support the viability of DDLT for CRLM using advanced perfusion, contingent on strict protocol adherence. Center-specific waitlist dynamics must inform the choice between DDLT and living donor liver transplant (LDLT).