Empowering Tomorrow's Cancer Specialists: Evaluating the Co-creation and Impact of Malawi's First Surgical Oncology Summerschool.

Annually more than 1 million newly diagnosed cancer cases and 500,000 cancer-related deaths occur in Sub Saharan Africa (SSA). By 2030, the cancer burden in Africa is expected to double accompanied by low survival rates. Surgery remains the primary treatment for solid tumours especially where other treatment modalities are lacking. However, in SSA, surgical residents lack sufficient training in cancer treatment. In 2022, Malawian and Dutch specialists co-designed a training course focusing on oncologic diseases and potential treatment options tailored to the Malawian context. The aim of this study was to describe the co-creation process of a surgical oncology education activity in a low resource setting, at the same time attempting to evaluate the effectiveness of this training program. The course design was guided and evaluated conform Kirkpatrick's requirements for an effective training program. Pre-and post-course questionnaires were conducted to evaluate the effectiveness. Thirty-five surgical and gynaecological residents from Malawi participated in the course. Eighty-six percent of respondents (n = 24/28) were highly satisfied at the end of the course. After a 2-month follow-up, 84% (n = 16/19) frequently applied the newly acquired knowledge, and 74% (n = 14/19) reported to have changed their patient care. The course costs were approximately 119 EUR per attendee per day. This course generally received generally positively feedback, had high satisfaction rates, and enhanced knowledge and confidence in the surgical treatment of cancer. Its effectiveness should be further evaluated using the same co-creation model in different settings. Integrating oncology into the regular curriculum of surgical residents is recommended.

Fibroblast activation protein identifies Consensus Molecular Subtype 4 in colorectal cancer and allows its detection by 68Ga-FAPI-PET imaging.

BACKGROUND: In colorectal cancer (CRC), the consensus molecular subtype 4 (CMS4) is associated with therapy resistance and poor prognosis. Clinical diagnosis of CMS4 is hampered by locoregional and temporal variables influencing CMS classification. Diagnostic tools that comprehensively detect CMS4 are therefore urgently needed. METHODS: To identify targets for molecular CMS4 imaging, RNA sequencing data of 3232 primary CRC patients were explored. Heterogeneity of marker expression in relation to CMS4 status was assessed by analysing 3-5 tumour regions and 91.103 single-tumour cells (7 and 29 tumours, respectively). Candidate marker expression was validated in CMS4 peritoneal metastases (PM; n = 59). Molecular imaging was performed using the 68Ga-DOTA-FAPI-46 PET tracer. RESULTS: Fibroblast activation protein (FAP) mRNA identified CMS4 with very high sensitivity and specificity (AUROC > 0.91), and was associated with significantly shorter relapse-free survival (P = 0.0038). Heterogeneous expression of FAP among and within tumour lesions correlated with CMS4 heterogeneity (AUROC = 1.00). FAP expression was homogeneously high in PM, a near-homogeneous CMS4 entity. FAPI-PET identified focal and diffuse PM that were missed using conventional imaging. Extra-peritoneal metastases displayed extensive heterogeneity of tracer uptake. CONCLUSION: FAP expression identifies CMS4 CRC. FAPI-PET may have value in the comprehensive detection of CMS4 tumours in CRC. This is especially relevant in patients with PM, for whom effective imaging tools are currently lacking.

Procedural Surgical RCTs in Daily Practice: Do Surgeons Adopt Or Is It Just a Waste of Time?

OBJECTIVE: To assess the adoption of recommendation from randomized clinical trials (RCTs) and investigate factors favoring or preventing adoption. BACKGROUND: RCT are considered to be the cornerstone of evidence-based medicine by representing the highest level of evidence. As such, we expect RCT's recommendations to be followed rigorously in daily surgical practice. METHODS: We performed a structured search for RCTs published in the medical and surgical literature from 2009 to 2013, allowing a minimum of 5-year follow-up to convincingly test implementation. We focused on comparative technical or procedural RCTs trials addressing the domains of general, colorectal, hepatobiliary, upper gastrointestinal and vascular surgery. In a second step we composed a survey of 29 questions among ESA members as well as collaborators from their institutions to investigate the adoption of surgical RCTs recommendation. RESULTS: The survey based on 36 RCTs (median 5-yr citation index 85 (24-474), from 21 different countries, published in 15 high-ranked journals with a median impact factor of 3.3 (1.23-7.9) at the time of publication. Overall, less than half of the respondents (47%) appeared to adhere to the recommendations of a specific RCT within their field of expertise, even when included in formal guidelines. Adoption of a new surgical practice was favored by watching videos (46%) as well as assisting live operations (18%), while skepticism regarding the methodology of a surgical RCT (40%) appears to be the major reason to resist adoption. CONCLUSION: In conclusion, surgical RCTs appear to have moderate impact on daily surgical practice. While RCTs are still accepted to provide the highest level of evidence, alternative methods of evaluating surgical innovations should also be explored.

Predictive factors for postoperative morbidity after laparoscopic adrenalectomy for pheochromocytoma: a multicenter retrospective analysis in 225 patients.

BACKGROUND: Since the 1950s, preoperative medical preparation has been widely applied in patients with pheochromocytoma to improve intraoperative hemodynamic instability and postoperative complications. However, advancements in preoperative imaging, laparoscopic surgical techniques, and anesthesia have considerably improved management in patients with pheochromocytoma. In consequence, there is no validated consensus on current predictive factors for postoperative morbidity. The aim of this study was to determine perioperative factors which are predictive for postoperative morbidity in patients undergoing laparoscopic adrenalectomy for pheochromocytoma. STUDY DESIGN: It is a retrospective analysis of prospectively maintained databases in five medical centers from 2002 to 2013. Inclusion criteria were consecutive patients who underwent non-converted laparoscopic unilateral total adrenalectomy for pheochromocytoma. RESULTS: Two-hundred and twenty-five patients were included. All-cause and cardiovascular postoperative morbidity rates were 16% (n = 36) and 4.8% (n = 11), respectively. Preinduction blood pressure normalization after preoperative medical preparation had no impact on postoperative morbidity. However, past medical history of coronary artery disease (OR [CI95%] = 3.39; [1.317-8.727]) and incidence of intraoperative hemodynamic instability episodes (both SBP ≥ 160 mmHg and MAP < 60 mmHg) (OR [CI95%] = 3.092; [1.451-6.587]) remained independent predictors for postoperative all-cause morbidity. Similarly, past medical history of coronary artery disease (OR [CI95%] = 14.41; [3.119-66.57]), female sex (OR [CI95%] = 12.05; [1.807-80.31]), and incidence of intraoperative hemodynamic instability episodes (both SBP ≥ 200 mmHg and MAP < 60 mmHg) (OR [CI95%] = 4.13; [1.009-16.90]) remained independent predictors for postoperative cardiovascular morbidity. CONCLUSIONS: This study identifies risk factors for cardiovascular and all-cause postoperative morbidity after laparoscopic adrenalectomy in current clinical setting. These data can help physicians to guide intra-operative blood pressure management and have to be taken into account in further studies.

Differential cytokine and chemokine expression after ablation vs. resection in colorectal cancer liver metastasis.

Background: Surgical resection remains the main curative treatment for colorectal liver metastases (CRLM). Radiofrequency ablation (RFA) is increasingly employed for small, deep lying or otherwise inoperable lesions. However, RFA can induce pro-tumorigenic effects on residual tumor cells, hereby possibly promoting tumor recurrence. Contrastingly, post-RFA tumor debris as an antigen source can also generate anti-cancer immune responses. Utilizing this, current studies on combining RFA with immune therapy appear promising. Here, in an attempt to shed light on this controversy, cytokines involved in inflammation, (lymph)angiogenesis, immune cell recruitment and tumor cell invasion were investigated post-RFA versus post-resection in CRLM patients. Methods: Cytokine and chemokine serum levels pre-operation, 4 h and 24 h post-operation were analyzed in CRLM patients undergoing RFA (n = 8) or partial hepatectomy (n = 9) using Multiplex immunoassays. Statistical analyses were performed between as well as within individual intervention groups. Results: Post-RFA, significantly increased levels of acute phase proteins SAA1 and S100A8, IL-6, IL-1Ra, MIP3b (CCL19) and MMP9 were observed along with decreases in Fibronectin, MCP-1 (CCL2), and Tie-2. Post-resection, increased levels of PDGFbb, I309 (CCL1), Apelin, MIF, IL-1b and TNFα were seen. All p-values <0.05. Conclusion: Pro-inflammatory responses mediated by different cytokines were seen after both RFA and resection, possibly influencing residual tumor cells and tumor recurrence. As both ablation and resection trigger inflammation and immune cell recruitment (albeit via distinct mechanisms), these data suggest that further research may explore combining immune therapy with not only RFA but also resection. Key message: Analysis of patients' serum after radiofrequency ablation versus resection of colorectal liver metastases (CRLM) showed that these interventions trigger inflammation and immune cell recruitment, via different cyto- and chemokine pathways. This suggests a possible future strategy of combining immune therapy with not only ablative techniques but also with resection of CRLM.

Co-cultures of colon cancer cells and cancer-associated fibroblasts recapitulate the aggressive features of mesenchymal-like colon cancer.

Background: Poor prognosis in colon cancer is associated with a high content of cancer-associated fibroblasts (CAFs) and an immunosuppressive tumor microenvironment. The relationship between these two features is incompletely understood. Here, we aimed to generate a model system for studying the interaction between cancer cells and CAFs and their effect on immune-related cytokines and T cell proliferation. Methods: CAFs were isolated from colon cancer liver metastases and were immortalized to prolong lifespan and improve robustness and reproducibility. Established medium and matrix compositions that support the growth of patient-derived organoids were adapted to also support CAF growth. Changes in growth pattern and cellular re-organization were assessed by confocal microscopy, live cell imaging, and immunofluorescence. Single cell RNA sequencing was used to study CAF/organoid co-culture-induced phenotypic changes in both cell types. Conditioned media were used to quantify the production of immunosuppressive factors and to assess their effect on T cell proliferation. Results: We developed a co-culture system in which colon cancer organoids and CAFs spontaneously organize into superstructures with a high capacity to contract and stiffen the extracellular matrix (ECM). CAF-produced collagen IV provided a basement membrane supporting cancer cell organization into glandular structures, reminiscent of human cancer histology. Single cell RNA sequencing analysis showed that CAFs induced a partial epithelial-to-mesenchymal-transition in a subpopulation of cancer cells, similar to what is observed in the mesenchymal-like consensus molecular subtype 4 (CMS4) colon cancer. CAFs in co-culture were characterized by high expression of ECM components, ECM-remodeling enzymes, glycolysis, hypoxia, and genes involved in immunosuppression. An expression signature derived from CAFs in co-culture identified a subpopulation of glycolytic myofibroblasts specifically residing in CMS1 and CMS4 colon cancer. Medium conditioned by co-cultures contained high levels of the immunosuppressive factors TGFß1, VEGFA and lactate, and potently inhibited T cell proliferation. Conclusion: Co-cultures of organoids and immortalized CAFs recapitulate the histological, biophysical, and immunosuppressive features of aggressive mesenchymal-like human CRC. The model can be used to study the mechanisms of immunosuppression and to test therapeutic strategies targeting the cross-talk between CAFs and cancer cells. It can be further modified to represent distinct colon cancer subtypes and (organ-specific) microenvironments.

Loss of Neuropilin-2 in Murine Mesenchymal-like Colon Cancer Organoids Causes Mesenchymal-to-Epithelial Transition and an Acquired Dependency on Insulin-Receptor Signaling and Autophagy.

Neuropilin-2 (Nrp2), an important regulator of lymphangiogenesis and lymphatic metastasis, has been associated with progression in colorectal cancer (CRC). However, the tumor cell-intrinsic role of Nrp2 in cancer progression is incompletely understood. To address this question, we employed CRISPR-Cas9 technology to generate Nrp2-knockout organoids derived from murine CRC tumors with a mesenchymal phenotype. Transcriptome profiling and tumor tissue analysis showed that Nrp2 loss resulted in mesenchymal-to-epithelial transition (MET), which was accompanied with restored polarity and tight junction stabilization. Signaling pathway analysis revealed that Nrp2-knockout organoids acquire de novo dependency on insulin receptor (IR) signaling and autophagy as alternative survival mechanisms. Combined inhibition of IR signaling and autophagy prevented the stabilization of cell-cell junctions, reduced metabolic activity, and caused profound cell death in Nrp2-knockout organoids. Collectively, the data demonstrate a key role for Nrp2 in maintaining the aggressive phenotype and survival of tumor-derived CRC organoids. The identified connection between Nrp2, insulin receptor signaling and autophagy may guide the development of novel combination-treatment strategies for aggressive CRC.

Long-Lived Human Lymphatic Endothelial Cells to Study Lymphatic Biology and Lymphatic Vessel/Tumor Coculture in a 3D Microfluidic Model.

The lymphatic system is essential in maintaining tissue fluid homeostasis as well as antigen and immune cell transport to lymph nodes. Moreover, lymphatic vasculature plays an important role in various pathological processes, such as cancer. Fundamental to this research field are representative in vitro models. Here we present a microfluidic lymphatic vessel model to study lymphangiogenesis and its interaction with colon cancer organoids using a newly developed lymphatic endothelial cell (LEC) line. We generated immortalized human LECs by lentiviral transduction of human telomerase (hTERT) and BMI-1 expression cassettes into primary LECs. Immortalized LECs showed an increased growth potential, reduced senescence, and elongated lifespan with maintenance of typical LEC morphology and marker expression for over 12 months while remaining nontransformed. Immortalized LECs were introduced in a microfluidic chip, comprising a free-standing extracellular matrix, where they formed a perfusable vessel-like structure against the extracellular matrix. A gradient of lymphangiogenic factors over the extracellular matrix gel induced the formation of luminated sprouts. Adding mouse colon cancer organoids adjacent to the lymphatic vessel resulted in a stable long-lived coculture model in which cancer cell-induced lymphangiogenesis and cancer cell motility can be investigated. Thus, the development of a stable immortalized lymphatic endothelial cell line in a membrane-free, perfused microfluidic chip yields a highly standardized lymphangiogenesis and lymphatic vessel-tumor cell coculture assay.

Surgical resection and radiofrequency ablation initiate cancer in cytokeratin-19+- liver cells deficient for p53 and Rb.

The long term prognosis of liver cancer patients remains unsatisfactory because of cancer recurrence after surgical interventions, particularly in patients with viral infections. Since hepatitis B and C viral proteins lead to inactivation of the tumor suppressors p53 and Retinoblastoma (Rb), we hypothesize that surgery in the context of p53/Rb inactivation initiate de novo tumorigenesis.We, therefore, generated transgenic mice with hepatocyte and cholangiocyte/liver progenitor cell (LPC)-specific deletion of p53 and Rb, by interbreeding conditional p53/Rb knockout mice with either Albumin-cre or Cytokeratin-19-cre transgenic mice.We show that liver cancer develops at the necrotic injury site after surgical resection or radiofrequency ablation in p53/Rb deficient livers. Cancer initiation occurs as a result of specific migration, expansion and transformation of cytokeratin-19+-liver (CK-19+) cells. At the injury site migrating CK-19+ cells formed small bile ducts and adjacent cells strongly expressed the transforming growth factor ß (TGFß). Isolated cytokeratin-19+ cells deficient for p53/Rb were resistant against hypoxia and TGFß-mediated growth inhibition. CK-19+ specific deletion of p53/Rb verified that carcinomas at the injury site originates from cholangiocytes or liver progenitor cells.These findings suggest that human liver patients with hepatitis B and C viral infection or with mutations for p53 and Rb are at high risk to develop tumors at the surgical intervention site.

Diagnostic value of routine aqueous contrast swallow examination after oesophagectomy for detecting leakage of the cervical oesophagogastric anastomosis.

BACKGROUND: Water-soluble contrast swallow examination is routinely carried out after oesophagectomy to detect leakage of the cervical oesophagogastric anastomosis. This study evaluated the diagnostic accuracy and clinical value. METHODS: Patients with oesophageal carcinoma who underwent oesophagectomy with gastric conduit formation and a hand-sewn cervical anastomosis between 1989 and 2003 were reviewed on outcome of routine aqueous contrast swallow examination (RACSE) and appearance of clinical anastomotic leakage. RESULTS: An RACSE was carried out in 207 (82%) of 252 patients on postoperative day 8 (range 3-15). In 45 patients, no RACSE was executed, mainly because of a prolonged stay in intensive care unit. In 18 (9%) of 207 cases, the RACSE could not be interpreted by the radiologist. In 19 (53%) of 36 patients who developed a clinical leakage, the leak had already manifested clinically before the routine contrast examination was planned. Taken together, the false-positive rate was 8%, the false-negative rate 48%, sensitivity 52%, specificity 92%, positive predictive value 46% and negative predictive value 93%. No significant differences were found between the accuracy of RACSE in end-to-end or end-to-side cervical anastomoses. CONCLUSION: Given the very low sensitivity and low positive predictive value and given the fact that in 53% of patients with a clinical leak, the leakage had appeared clinically before the contrast swallow examination was routinely planned, we propose to abandon the routine contrast swallow examination after oesophagectomy to detect cervical anastomotic leakage. Alternatively, anastomotic integrity can be tested by drinking small amounts of water with simultaneous observation of the cervical wound.