Nationwide validation of the distal fistula risk score (D-FRS).

PURPOSE: Distal pancreatectomy (DP) is associated with a high complication rate of 30-50% with postoperative pancreatic fistula (POPF) as a dominant contributor. Adequate risk estimation for POPF enables surgeons to use a tailor-made approach. Assessment of the risk of POPF prior to DP can lead to the application of preventive strategies. The current study aims to validate the recently published preoperative and intraoperative distal fistula risk score (D-FRS) in a nationwide cohort. METHODS: This nationwide retrospective Dutch cohort study included all patients after DP for any indication, all of whom were registered in the Dutch Pancreatic Cancer Audit (DPCA) database between 2013 and 2021. The D-FRS was validated by filling in the probability equations with data from this cohort. The predictive capacity of the models was represented by an area under the receiver operating characteristic (AUROC) curve. RESULTS: A total of 896 patients underwent DP of which 152 (17%) developed POPF of whom 144 grade B (95%) and 8 grade C (5%). The preoperative D-FRS, consisting of the variables pancreatic neck thickness and pancreatic duct diameter, showed an AUROC of 0.73 (95%CI 0.68-0.78). The intraoperative D-FRS, comprising pancreatic neck, duct diameter, BMI, operating time, and soft pancreatic aspect, showed an AUROC of 0.69 (95%CI 0.64-0.74). CONCLUSION: The current study is the first nationwide validation of the preoperative and intraoperative D-FRS showing acceptable distinguishing capacity for only the preoperative D-FRS for POPF. Therefore, the preoperative score could improve prevention and mitigation strategies such as drain management, which is currently investigated in the multicenter PANDORINA trial.

Volume-outcome relationship of liver surgery: a nationwide analysis.

BACKGROUND: Evidence for an association between hospital volume and outcomes for liver surgery is abundant. The current Dutch guideline requires a minimum volume of 20 annual procedures per centre. The aim of this study was to investigate the association between hospital volume and postoperative outcomes using data from the nationwide Dutch Hepato Biliary Audit. METHODS: This was a nationwide study in the Netherlands. All liver resections reported in the Dutch Hepato Biliary Audit between 2014 and 2017 were included. Annual centre volume was calculated and classified in categories of 20 procedures per year. Main outcomes were major morbidity (Clavien-Dindo grade IIIA or higher) and 30-day or in-hospital mortality. RESULTS: A total of 5590 liver resections were done across 34 centres with a median annual centre volume of 35 (i.q.r. 20-69) procedures. Overall major morbidity and mortality rates were 11·2 and 2·0 per cent respectively. The mortality rate was 1·9 per cent after resection for colorectal liver metastases (CRLMs), 1·2 per cent for non-CRLMs, 0·4 per cent for benign tumours, 4·9 per cent for hepatocellular carcinoma and 10·3 per cent for biliary tumours. Higher-volume centres performed more major liver resections, and more resections for hepatocellular carcinoma and biliary cancer. There was no association between hospital volume and either major morbidity or mortality in multivariable analysis, after adjustment for known risk factors for adverse events. CONCLUSION: Hospital volume and postoperative outcomes were not associated.

ANTECEDENTES: La asociación entre el volumen hospitalario y los resultados de la cirugía hepática no está clara. Según la recomendación actual de las guías holandesas se requiere un volumen mínimo de 20 procedimientos anuales por centro. El objetivo de este estudio fue analizar la asociación entre el volumen hospitalario con los resultados postoperatorios en la auditoría hepatobiliar obligatoria holandesa a nivel nacional. MÉTODOS: Se realizó un estudio a nivel nacional en los Países Bajos. Se incluyeron todas las resecciones hepáticas registradas en la auditoría hepatobiliar holandesa entre 2014 y 2017. El volumen anual del centro se calculó y se clasificó en categorías de 20 procedimientos por año. Los objetivos principales fueron la morbilidad de mayor grado (Clavien-Dindo grado IIIA o superior) y la mortalidad hospitalaria o la mortalidad a los 30 días. RESULTADOS: Se realizaron un total de 5.590 resecciones en 34 centros con una mediana (rango intercuartílico) de volumen anual de 35 procedimientos (20-69). La tasa global de morbilidad mayor fue del 11% y la mortalidad del 2%. La mortalidad fue de 1,9% después de la resección por metástasis hepáticas colorrectales (colorectal liver metastases, CRLM), 1,2% para no CRLM, 0,4% para tumores benignos, 4,9% para carcinoma hepatocelular, y 10,3% para tumores biliares. Los centros de mayor volumen realizaron más resecciones hepáticas mayores y más resecciones por carcinoma hepatocelular y cáncer biliar. En el análisis multivariable después de ajustar por factores de riesgo conocidos de eventos adversos, no se observó ninguna asociación entre el volumen hospitalario y la morbilidad o mortalidad mayor. CONCLUSIÓN: No hubo asociación entre el volumen hospitalario y los resultados postoperatorios de la cirugía hepática en los Países Bajos.

The Dutch surgical colorectal audit.

INTRODUCTION: In 2009, the nationwide Dutch Surgical Colorectal Audit (DSCA) was initiated by the Association of Surgeons of the Netherlands (ASN) to monitor, evaluate and improve colorectal cancer care. The DSCA is currently widely used as a blueprint for the initiation of other audits, coordinated by the Dutch Institute for Clinical Auditing (DICA). This article illustrates key elements of the DSCA and results of three years of auditing. METHODS: Key elements include: a leading role of the professional association with integration of the audit in the national quality assurance policy; web-based registration by medical specialists; weekly updated online feedback to participants; annual external data verification with other data sources; improvement projects. RESULTS: In two years, all Dutch hospitals participated in the audit. Case-ascertainment was 92% in 2010 and 95% in 2011. External data verification by comparison with the Netherlands Cancer Registry (NCR) showed high concordance of data items. Within three years, guideline compliance for diagnostics, preoperative multidisciplinary meetings and standardised reporting increased; complication-, re-intervention and postoperative mortality rates decreased significantly. DISCUSSION: The success of the DSCA is the result of effective surgical collaboration. The leading role of the ASN in conducting the audit resulted in full participation of all colorectal surgeons in the Netherlands. By integrating the audit into the ASNs' quality assurance policy, it could be used to set national quality standards. Future challenges include reduction of administrative burden; expansion to a multidisciplinary registration; and addition of financial information and patient reported outcomes to the audit data.

Isolated limb perfusion for local gene delivery: efficient and targeted adenovirus-mediated gene transfer into soft tissue sarcomas.

OBJECTIVE: To evaluate the potential of isolated limb perfusion (ILP) for efficient and tumor-specific adenovirus-mediated gene transfer in sarcoma-bearing rats. SUMMARY BACKGROUND DATA: A major concern in adenovirus-mediated gene therapy in cancer is the transfer of genes to organs other than the tumor, especially organs with a rapid cell turnover. Adjustment of the vector delivery route might be an option creating tumor specificity in therapeutic gene expression. METHODS: Rat hind limb sarcomas (5-10 mm) were transfected with recombinant adenoviruses. Intratumoral luciferase expression after ILP was compared with systemic administration, regional infusion, or intratumoral injection using a similar dose of adenoviruses carrying the luciferase marker gene. Localization studies using lacZ as a marker gene were performed to evaluate the intratumoral distribution of transfected cells after both ILP and intratumoral injection. RESULTS: Intratumoral luciferase activity after ILP or intratumoral administration was significantly higher compared with regional infusion or systemic administration. After ILP, luciferase gene expression was minimal in extratumoral organs, whether outside or inside the isolated circuit. Localization studies demonstrated that transfection was confined to tumor cells lying along the needle track after intratumoral injection, whereas after ILP, lacZ expression was found in viable tumor cells and in the tumor-associated vasculature. CONCLUSIONS: Using ILP, efficient and tumor-specific gene transfection can be achieved. The ILP technique might be useful for the delivery of recombinant adenoviruses carrying therapeutic gene constructs to enhance tumor control.

Nitric oxide synthase inhibition results in synergistic anti-tumour activity with melphalan and tumour necrosis factor alpha-based isolated limb perfusions.

Nitric oxide (NO) is an important molecule in regulating tumour blood flow and stimulating tumour angiogenesis. Inhibition of NO synthase by L-NAME might induce an anti-tumour effect by limiting nutrients and oxygen to reach tumour tissue or affecting vascular growth. The anti-tumour effect of L-NAME after systemic administration was studied in a renal subcapsular CC531 adenocarcinoma model in rats. Moreover, regional administration of L-NAME, in combination with TNF and melphalan, was studied in an isolated limb perfusion (ILP) model using BN175 soft-tissue sarcomas. Systemic treatment with L-NAME inhibited growth of adenocarcinoma significantly but was accompanied by impaired renal function. In ILP, reduced tumour growth was observed when L-NAME was used alone. In combination with TNF or melphalan, L-NAME increased response rates significantly compared to perfusions without L-NAME (0-64% and 0-63% respectively). An additional anti-tumour effect was demonstrated when L-NAME was added to the synergistic combination of melphalan and TNF (responses increased from 70 to 100%). Inhibition of NO synthase reduces tumour growth both after systemic and regional (ILP) treatment. A synergistic anti-tumour effect of L-NAME is observed in combination with melphalan and/or TNF using ILP. These results indicate a possible role of L-NAME for the treatment of solid tumours in a systemic or regional setting.

Isolated limb perfusion with tumour necrosis factor-alpha and melphalan for unresectable bone sarcomas of the lower extremity.

AIMS: Isolated limb perfusion (ILP) with recombinant tumour necrosis factor-alpha (rTNF-alpha) and melphalan has recently been reported to induce major tumour responses and permit limb salvage in over 80% of patients with unresectable soft-tissue sarcomas of the extremities. We investigated whether TNF-based ILP could allow limb-sparing surgery in patients with primary, recurrent or metastatic bone sarcoma to the lower extremity who met the criteria for an amputation and had failed or refused chemotherapy. METHODS: From August 1992 to December 1997, we employed ILP with rTNF-alpha and melphalan in 13 patients with unresectable bone sarcoma of the lower extremity, all of whom were candidates for amputation. The aim was to reduce tumour size and allow the performance of a limb-sparing surgery (LSS). RESULTS: Following ILP, none of the patients had severe local toxicity and only one patient experienced significant systemic side-effects. LSS was subsequently performed in nine of the 13 patients. LSS was feasible in an additional three patients but was not performed because of the emergence of diffused metastatic disease. CONCLUSIONS: ILP with rTNF-alpha and melphalan can allow limb salvage in patients wih locally advanced bone sarcomas who had failed standard treatment options. Its potential role in the treatment of unresectable bone sarcomas of the extremities merits further evaluation.

Prerequisites for effective isolated limb perfusion using tumour necrosis factor alpha and melphalan in rats.

An isolated limb perfusion (ILP) model using soft tissue sarcoma-bearing rats was used to study prerequisites for an effective ILP, such as oxygenation of the perfusate, temperature of the limb, duration of the perfusion and concentration of tumour necrosis factor (TNF). Combination of 50 microg TNF and 40 microg melphalan demonstrated synergistic activity leading to a partial and complete response rate of 71%. In comparison to oxygenated ILP, hypoxia was shown to enhance anti-tumour activity of melphalan alone and TNF alone but not of their combined use. Shorter perfusion times decreased anti-tumour responses. At a temperature of 24-26 degrees C, anti-tumour effects were lost, whereas temperatures of 38-39 degrees C or 42-43 degrees C resulted in higher response rates. However, at 42-43 degrees C, local toxicity impaired limb function dramatically. Synergy between TNF and melphalan was lost at a dose of TNF below 10 microg in 5 ml perfusate. We conclude that the combination of TNF and melphalan has strong synergistic anti-tumour effects in our model, just as in the clinical setting. Hypoxia enhanced activity of melphalan and TNF alone but not the efficacy of their combined use. For an optimal ILP, minimal perfusion time of 30 min and minimal temperature of 38 degrees C was mandatory. Moreover, the dose of TNF could be lowered to 10 microg per 5 ml perfusate, which might allow the use of TNF in less leakage-free or less inert perfusion settings.

Toxicity and antitumor activity of interferon gamma alone and in combinations with TNFalpha and melphalan in isolated limb perfusion in the BN175 sarcoma tumor model in rats.

Isolated limb perfusion (ILP) with TNFalpha, melphalan (M), and IFNgamma results in high tumor response rates in patients with soft tissue sarcomas, melanomas and other tumors. IFNgamma can act synergistically in combination with TNFalpha but in clinical studies this has not been fully investigated. In the BN175 rat sarcoma limb perfusion model we investigated the role of IFNgamma. There were 8 different treatment groups: (I) sham ILP (n=9); (II) IFNgamma alone (n=10); (III) TNFalpha 50 microg (n=9); (IV) TNFalpha + IFNgamma (n=6); (V) melphalan (M) 40 microg (n=11); (VI) M + IFNgamma (n=6); (VII) TNFalpha + M (n=27); (VIII) TNFalpha + M + IFNgamma (n=9). Tumor response and hindlimb function were analyzed. In group I-VI no tumor regressions were observed at 5 days after ILP. ILP with TNFalpha + M had highly effective response rate (RR) of 73%; complete response (CR) rate 55%), very similar to RR in patients. Addition of IFNgamma increased the RR by 16% to 89% and the CR rate by 23% to 78%. This difference was not statistically significant. When IFNgamma was added to TNFalpha or TNFalpha + M it increased limb toxicity significantly (p<0.05 and p<0.005). Since such regional toxicity has not been observed in patients while similar increases in tumor response rates have been reported with IFNgamma it is of importance to define the role of IFNgamma in the clinical setting.

Assessment of the role of neutrophils on the antitumor effect of TNFalpha in an in vivo isolated limb perfusion model in sarcoma-bearing brown Norway rats.

INTRODUCTION: Isolated limb perfusion (ILP) with TNFalpha in combination with melphalan and IFNgamma has resulted in an immediate and dramatic tumor response in patients. Such an effect was also noted following ILP in a rat sarcoma model. This model enables us to investigate several factors responsible for the TNFalpha-induced tumor responses. We applied total body irradiation (TBI) to reduce white blood cell count, to investigate the contribution of leukocytes to the anti-tumor effect of TNFalpha. METHODS: Small fragments of the nonimmunogenic BN 175 sarcoma were implanted sc in the lower hind leg. A 5 Gy TBI was performed before ILP at a tumor diameter of approximately 15 mm. The hind limbs of 63 rats were perfused and were divided into 6 groups: group 1, sham perfusion, n = 9; group 2, TBI + sham perfusion, n = 6; group 3, TNFalpha 50 microgram, n = 9; group 4, melphalan 40 microgram, n = 9; group 5, TNFalpha 50 microgram + melphalan 40 microgram, n = 22; group 6, TBI + TNFalpha + melphalan ILP, n = 8. In addition, 10 rats were perfused for histological analysis at 24 h post-ILP. RESULTS: We observed in Group 1: 9/9 progressive disease (PD); Group 2: 6/6 PD; Group 3: 9/9 PD; Group 4: 9/9 no change (NC) of tumor diameter for at least 4 days; Group 5: 6/22 NC, 16/22 complete remission (CR), 12/16 of which showed skin necrosis at the tumor site; and Group 6: 7/8 NC and 1/8 CR (without skin necrosis). After TBI, WBC reduction of 80-95% was observed, while the number of platelets was not significantly reduced and platelet aggregation was maintained at 72 %. Histological analysis revealed decreased hemorrhagic necrosis associated with the absence of PMN infiltration at the tumor margins in the TBI rats. CONCLUSION: TBI and the associated reduction in WBC count decreased the tumor response by TNFalpha and melphalan significantly and abrogated the immediate response of skin necrosis at the tumor site, as found in rats treated with TNFalpha and melphalan without TBI. These data strongly suggest that leukocytes play an important role in the hemorrhagic effects of TNFalpha.

Tumor necrosis factor-alpha in isolated perfusion systems in the treatment of cancer: the Rotterdam preclinical-clinical program.

The clinical success of the application of tumor necrosis factor-alpha (TNFalpha) in isolated limb perfusions in patients with advanced sarcomas, melanomas and other tumors has renewed the interest in this agent as an anticancer drug. At the Rotterdam Cancer Center, we have developed an interactive preclinical-clinical TNFalpha program that explores new methods to use TNFalpha in various settings. Regional organ perfusion models were developed and the effectivity of targeting of TNFalpha to the tumor by means of systemic administration of liposomes are tested. Furthermore various drugs and mechanisms that may enhance the activity of TNFalpha are under investigation. A summary of this comprehensive program is presented here.

Synergistic effects of TNF-alpha and melphalan in an isolated limb perfusion model of rat sarcoma: a histopathological, immunohistochemical and electron microscopical study.

Isolated limb perfusion (ILP) with tumour necrosis factor alpha (TNF-alpha) and melphalan has shown impressive results in patients with irresectable soft tissue sarcomas and stage III melanoma of the extremities. The mechanisms of the reported in vivo synergistic anti-tumour effects of TNF-alpha and melphalan are not precisely understood. We have developed an ILP model in the rat using a non-immunogenic sarcoma in which similar in vivo synergy is observed. The aim of this present study was to analyse the morphological substrate for this synergistic response of TNF-alpha in combination with melphalan to shed more light on the pathomechanisms involved. Histology of the tumours from saline- (n = 14) and melphalan-treated (n = 11) rats revealed apparently vital tumour cells in over 80% of the cross-sections. Interstitial oedema and coagulation necrosis were observed in the remaining part of the tumour. Haemorrhage was virtually absent. TNF-alpha (n = 22) induced marked oedema, hyperaemia, vascular congestion, extravasation of erythrocytes and haemorrhagic necrosis (20-60% of the cross-sections). Oedema and haemorrhage suggested drastic alterations of permeability and integrity of the microvasculature. Using light and electron-microscopy, we observed that haemorrhage preceded generalised platelet aggregation. Therefore, we suggest that the observed platelet aggregation was the result of the microvascular damage rather than its initiator. Remarkably, these events hardly influenced tumour growth. However, perfusion with the combination of TNF-alpha and melphalan (n = 24) showed more extensive haemorrhagic necrosis (80-90% of the cross-sections) and revealed a prolonged remission (mean 11 days) in comparison with the other groups of rats. Electron microscopical analysis revealed similar findings as described after TNF-alpha alone, although the effects were more prominent at all time points after perfusion. In conclusion, our findings suggest that the enhanced anti-tumour effect after the combination of TNF-alpha with melphalan results from potentiation of the TNF-alpha-induced vascular changes accompanied by increased vascular permeability and platelet aggregation. This may result in additive cytotoxicity or inhibition of growth of residual tumour cells.

Isolated limb perfusion with TNF alpha and melphalan in a rat osteosarcoma model: a new anti-tumour approach.

Isolated limb perfusion (ILP) with TNF alpha, IFN gamma and melphalan causes impressive tumour reduction in patients with irresectable soft tissue sarcomas with a high limb salvage rate. Since this therapy could be of value in patients with progressive osteosarcoma, we performed a study in an osteosarcoma tumour model in the rat. The ROS-1 osteosarcoma was implanted s.c. in the hind leg of WAG rats. Rats were divided in four groups: rats that underwent ILP with perfusate alone, TNF alpha alone, melphalan alone or their combination. Almost all rats, treated with a sham ILP or a perfusion with 40 micrograms melphalan, showed progressive disease (PD) (6/6 and 5/6). After perfusion with 50 micrograms TNF alpha alone a varied response was observed: 2/6 PD, 2/6 no change (NC) and 2/6 a complete remission (CR). After combined perfusion: 3/6 rats had a partial remission and 3/6 a CR. The best and most consistent responses are obtained by combining TNF alpha and melphalan. The discrepancy with the in vitro sensitivity of ROS-1 indicates that indirect effects are important in this tumour model.

Synergistic antitumour effect of recombinant human tumour necrosis factor alpha with melphalan in isolated limb perfusion in the rat.

The efficacy of isolated limb perfusion (ILP) for 'intransit' metastases from malignant melanoma and irresectable soft tissue sarcoma has been improved considerably by the addition of tumour necrosis factor (TNF) alpha. A rat sarcoma tumour model was, therefore, developed to evaluate the effects of TNF-alpha, melphalan and the combination of these drugs in the treatment of sarcoma. In BN rats bearing the non-immunogenic BN 175 sarcoma ILPs were performed with perfusate only, TNF-alpha, melphalan alone, or in combination when tumours had grown to approximately 1.5 cm in diameter. All rats treated with sham perfusion or perfusion with 50 micrograms TNF-alpha showed progressive disease. After perfusion with 40 micrograms melphalan no change in tumour diameter was observed in any rats at 4 days. After a combined perfusion with 40 micrograms melphalan and 50 micrograms TNF-alpha complete remission was noted in 12 of 16 rats. This synergistic effect in vivo between relatively ineffective doses of TNF-alpha and melphalan was not observed in vitro.

Regional application of TNF alpha in the treatment of cancer: a preclinical-clinical interactive program.

The clinical success of the application of TNF-alpha in the setting of isolated limb perfusions in patients with advanced sarcomas, melanomas and other tumors has renewed the interest in TNF alpha as an anticancer drug in man. We have developed an interactive preclinical-clinical TNF alpha program that explores new methods to use TNF alpha in various settings or enhance its activity. Thus we have developed regional organ perfusion models and are testing the effectivity of targeting of TNF to the tumor by means systemic administration of long circulating liposomes. Furthermore various drugs and mechanisms that may enhance the activity of TNF alpha are under investigation. An overview of this comprehensive program is presented here.