Contour prognostic model for predicting survival after resection of colorectal liver metastases: development and multicentre validation study using largest diameter and number of metastases with RAS mutation status.

BACKGROUND: Most current models for predicting survival after resection of colorectal liver metastasis include largest diameter and number of colorectal liver metastases as dichotomous variables, resulting in underestimation of the extent of risk variation and substantial loss of statistical power. The aim of this study was to develop and validate a new prognostic model for patients undergoing liver resection including largest diameter and number of colorectal liver metastases as continuous variables. METHODS: A prognostic model was developed using data from patients who underwent liver resection for colorectal liver metastases at MD Anderson Cancer Center and had RAS mutational data. A Cox proportional hazards model analysis was used to develop a model based on largest colorectal liver metastasis diameter and number of metastases as continuous variables. The model results were shown using contour plots, and validated externally in an international multi-institutional cohort. RESULTS: A total of 810 patients met the inclusion criteria. Largest colorectal liver metastasis diameter (hazard ratio (HR) 1.11, 95 per cent confidence interval 1.06 to 1.16; P < 0.001), number of colorectal liver metastases (HR 1.06, 1.03 to 1.09; P < 0.001), and RAS mutation status (HR 1.76, 1.42 to 2.18; P < 0.001) were significantly associated with overall survival, together with age, primary lymph node metastasis, and prehepatectomy chemotherapy. The model performed well in the external validation cohort, with predicted overall survival values almost lying within 10 per cent of observed values. Wild-type RAS was associated with better overall survival than RAS mutation even when liver resection was performed for larger and/or multiple colorectal liver metastases. CONCLUSION: The contour prognostic model, based on diameter and number of lesions considered as continuous variables along with RAS mutation, predicts overall survival after resection of colorectal liver metastasis.

Comparison of oncological outcomes after open and laparoscopic re-resection of incidental gallbladder cancer.

BACKGROUND: The safety and oncological efficacy of laparoscopic re-resection of incidental gallbladder cancer have not been studied. This study aimed to compare laparoscopic with open re-resection of incidentally discovered gallbladder cancer while minimizing selection bias. METHODS: This was a multicentre retrospective observational cohort study of patients with incidental gallbladder cancer who underwent re-resection with curative intent at four centres between 2000 and 2017. Overall survival (OS) and recurrence-free survival (RFS) were analysed by intention to treat. Inverse probability of surgery treatment weighting using propensity scoring was undertaken. RESULTS: A total of 255 patients underwent re-resection (190 open, 65 laparoscopic). Nineteen laparoscopic procedures were converted to open operation. Surgery before 2011 was the only factor associated with conversion. Duration of hospital stay was shorter after laparoscopic re-resection (median 4 versus 6 days; P < 0·001). Three-year OS rates for laparoscopic and open re-resection were 87 and 62 per cent respectively (P = 0·502). Independent predictors of worse OS were residual cancer found at re-resection (hazard ratio (HR) 1·91, 95 per cent c.i. 1·17 to 3·11), blood loss of at least 500 ml (HR 1·83, 1·23 to 2·74) and at least four positive nodes (HR 3·11, 1·46 to 6·65). In competing-risks analysis, the RFS incidence was higher for laparoscopic re-resection (P = 0·038), but OS did not differ between groups. Independent predictors of worse RFS were one to three positive nodes (HR 2·16, 1·29 to 3·60), at least four positive nodes (HR 4·39, 1·96 to 9·82) and residual cancer (HR 2·42, 1·46 to 4·00). CONCLUSION: Laparoscopic re-resection for selected patients with incidental gallbladder cancer is oncologically non-inferior to an open approach. Dissemination of advanced laparoscopic skills and timely referral of patients with incidental gallbladder cancer to specialized centres may allow more patients to benefit from this operation.

ANTECEDENTES: No se conoce la seguridad y la eficacia oncológica de la re-resección laparoscópica del cáncer incidental de vesícula biliar. Este estudio tiene como objetivo comparar las re-resecciones del cáncer incidental de vesícula biliar por vía laparoscópica y vía abierta, minimizando el sesgo de selección. MÉTODOS: Estudio de cohortes observacional, retrospectivo y multicéntrico de pacientes con cáncer incidental de vesícula biliar que se sometieron a una re-resección con intención curativa en 4 centros entre 2000 y 2017. Se analizó la supervivencia global (overall survival, OS) y la supervivencia libre de recidiva (recurrence free survival, RFS) según intención de tratamiento. Se calculó la probabilidad inversa de la ponderación del tratamiento quirúrgico utilizando puntuación de propensión. RESULTADOS: Se incluyeron 255 pacientes con re-resección (190 por vía abierta y 65 por vía laparoscópica). Se convirtieron 19 pacientes del grupo laparoscópico. El único factor relacionado con la conversión fue la realización de la cirugía antes de año 2011. La mediana de la estancia hospitalaria fue más corta tras la re-resección laparoscópica (4 versus 6 días; P < 0,001). La OS a tres años fue del 87% y del 62% (P = 0,502) para las re-resecciones laparoscópicas y abiertas, respectivamente). Los factores predictivos independientes relacionados con una peor OS fueron el hallazgo de cáncer residual en el momento de la re-resección (cociente de riesgos instantáneos, hazard ratio, HR 1,91; i.c. del 95% 1,17-3,11), una pérdida hemática > 500 ml (HR 1,83; i.c. del 95% 1,23-2,74) y la presencia de ≥ 4 ganglios positivos (HR 3,11; i.c. del 95% 1,46-6,65). En el análisis de riesgo competitivo, la RFS fue mayor para la resección laparoscópica (P = 0,038), pero no hubo diferencias en la OS entre ambos grupos. Los factores predictivos independientes de peor RFS fueron la detección de 1-3 ganglios positivos (HR 2,16; i.c. del 95% 1,29-3,60), ≥ 4 ganglio positivos (HR 4,39; i.c. del 95% 1,96-9,82) y el cáncer residual (HR 2,42; i.c. de 95% 1,46-4,0). CONCLUSIÓN: En pacientes seleccionados, los resultados oncológicos de la re-resección laparoscópica de un cáncer incidental de vesícula biliar no son inferiores a los que se obtienen por vía abierta. Una mayor difusión de las técnicas laparoscópicas avanzadas y una oportuna derivación de los pacientes con cáncer de vesícula biliar incidental a centros especializados podrían permitir que un mayor número de pacientes se beneficiaran de este abordaje.

Performance of a modified three-level classification in stratifying open liver resection procedures in terms of complexity and postoperative morbidity.

BACKGROUND: Traditional classifications for open liver resection are not always associated with surgical complexity and postoperative morbidity. The aim of this study was to test whether a three-level classification for stratifying surgical complexity based on surgical and postoperative outcomes, originally devised for laparoscopic liver resection, is superior to classifications based on a previously reported survey for stratifying surgical complexity of open liver resections, minor/major nomenclature or number of resected segments. METHODS: Patients undergoing a first open liver resection without simultaneous procedures at MD Anderson Cancer Center (Houston cohort) or the University of Tokyo (Tokyo cohort) were studied. Surgical and postoperative outcomes were compared among three grades: I (wedge resection for anterolateral or posterosuperior segment and left lateral sectionectomy); II (anterolateral segmentectomy and left hepatectomy); III (posterosuperior segmentectomy, right posterior sectionectomy, right hepatectomy, central hepatectomy and extended left/right hepatectomy). RESULTS: In both the Houston (1878 patients) and Tokyo (1202) cohorts, duration of operation, estimated blood loss and comprehensive complication index score differed between the three grades (all P < 0·050) and increased in stepwise fashion from grades I to III (all P < 0·001). Left hepatectomy was associated with better surgical and postoperative outcomes than right hepatectomy, extended right hepatectomy and right posterior sectionectomy, although these four procedures were categorized as being of medium complexity in the survey-based classification. Surgical outcomes of minor open liver resections also differed between the three grades (all P < 0·050). For duration of operation and blood loss, the area under the curve was higher for the three-level classification than for the minor/major or segment-based classification. CONCLUSION: The three-level classification may be useful in studies analysing open liver resection at Western and Eastern centres.

ANTECEDENTES: Las clasificaciones tradicionales de la resección hepática abierta (open liver resection, OLR) por número de segmentos resecados, no siempre se asocian con la complejidad quirúrgica y la morbilidad postoperatoria. El objetivo de este estudio fue comprobar si una clasificación de 3 niveles para estratificar la complejidad quirúrgica en función de los resultados quirúrgicos y postoperatorios, ideada originalmente para la resección hepática laparoscópica, es superior a las clasificaciones basadas en una encuesta descrita previamente para estratificar la complejidad quirúrgica de los procedimientos de OLR, nomenclatura menor/mayor, o número de segmentos resecados. MÉTODOS: Se estudiaron pacientes sometidos a una primera OLR sin otros procedimientos quirúrgicos concomitantes en el hospital MD Anderson (cohorte de Houston) o en la Universidad de Tokio (cohorte de Tokio). Se compararon los resultados quirúrgicos y postoperatorios entre 3 grados: I (resección limitada para el segmento anterolateral o posterosuperior y seccionectomía izquierda); II (segmentectomía anterolateral y hepatectomía izquierda); III (segmentectomía posterosuperior, seccionectomía posterior derecha, hepatectomía derecha, hepatectomía central y hepatectomía ampliada izquierda/derecha). RESULTADOS: En ambas cohortes de Houston (n = 1.878) y Tokio (n = 1.202), el tiempo operatorio, las pérdidas estimadas de sangre, y el índice de complejidad integral (comprehensive complication index) variaba en los 3 grados (todos P < 0,05) y aumentaba paso a paso desde los grados I a III (todos P < 0,05). La hepatectomía izquierda se asociaba con mejores resultados quirúrgicos y postoperatorios que la hepatectomía derecha, hepatectomía derecha ampliada, y seccionectomía posterior derecha, aunque estos cuatro procedimientos fueron categorizados como de complejidad intermedia en la clasificación basada en la encuesta. Los resultados quirúrgicos de las OLRs menores también variaron en los 3 grados (todos P < 0,05). Para el tiempo operatorio y la pérdida sanguínea, el área bajo la curva fue mayor para la clasificación de 3 niveles en el estudio actual, que para la clasificación menor/mayor o la clasificación basada en los segmentos. CONCLUSIÓN: La clasificación en 3 niveles puede ser útil en estudios que analizan las resecciones hepáticas abiertas en centros occidentales y orientales.

Prognostic impact of perihepatic lymph node metastases in patients with resectable colorectal liver metastases.

BACKGROUND: Although perihepatic lymph node metastases (PLNMs) are known to be a poor prognosticator for patients with colorectal liver metastases (CRLMs), optimal management remains unclear. This study aimed to determine the risk factors for PLNMs, and the survival impact of their number and location in patients with resectable CRLMs. METHODS: Data on patients with CRLM who underwent hepatectomy during 2003-2014 were analysed retrospectively. Recurrence-free (RFS) and overall (OS) survival were calculated according to presence, number and location of PLNMs. Risk factors for PLNM were evaluated by logistic regression analysis. RESULTS: Of 1485 patients, 174 underwent lymphadenectomy, and 54 (31·0 per cent) had PLNM. Ten patients (5·7 per cent) who had lymphadenectomy and 176 (13·4 per cent) who did not underwent repeat hepatectomy. Survival of patients with PLNM was significantly poorer than that of patients without (RFS: 5·3 versus 13·8 months, P < 0·001; OS: 20·5 versus 71·3 months; P < 0·001). Median OS was significantly better in patients with para-aortic versus hepatoduodenal ligament PLNMs (58·2 versus 15·5 months; P = 0·011). Patients with three or more PLNMs had significantly worse median OS than those with one or two (16·3 versus 25·4 months; P = 0·039). The presence of primary tumour lymph node metastases (odds ratio 2·35; P = 0·037) and intrahepatic recurrence requiring repeat hepatectomy (odds ratio 5·61; P = 0·012) were significant risk factors for PLNM on multivariable analysis. CONCLUSION: Patients undergoing repeat hepatectomy and those with primary tumour lymph node metastases are at significant risk of PLNM. Although PLNM is a poor prognostic factor independent of perihepatic lymph node station, patients with one or two PLNMs have a more favourable outcome than those with more PLNMs.

Extended pharmacologic thromboprophylaxis in oncologic liver surgery is safe and effective.

Essentials The risk for venous thromboembolism after liver surgery remains high in the modern era. We evaluated the safety/efficacy of extended anticoagulation in liver surgery. This protocol reports zero venous thromboembolism events in 124 liver surgery patients. Extended anticoagulation after oncologic liver surgery is safe and effective. SUMMARY: Background The incidence of venous thromboembolism (VTE) after liver surgery remains high. Objective To evaluate the safety and efficacy of extended pharmacologic thromboprophylaxis after liver surgery for the prevention of VTE. Patient/Methods From August 2013 to April 2015, 124 patients who underwent liver resection for malignancy were placed on an extended pharmacologic thromboprophylaxis protocol. Intraoperative VTE prophylaxis included thromboembolic deterrent hoses and sequential compression devices. Once hemostasis had been ensured following hepatectomy, daily anticoagulant VTE prophylaxis was initiated for the duration of hospitalization. After hospital discharge, the large majority of patients (114, 91.9%) continued to receive anticoagulant thromboprophylaxis (enoxaparin) to complete a total course of 14 days after minor/minimally invasive hepatectomy or 28 days after major hepatectomy or a history of VTE. Results The cohort included 39 (31.2%) major hepatectomies and 38 (31.5%) minor/minimally invasive approaches. The intraoperative, postoperative and overall transfusion rates were 5.6%, 8.1%, and 10.5%, respectively. Pharmacologic thromboprophylaxis was started on postoperative day (POD) 0 for 40 (32.3%) patients and on POD 1 for 84 (67.7%) patients. During 90 days of follow-up, no postoperative symptomatic deep vein thrombosis or pulmonary embolic events were diagnosed. Standard-protocol computed tomography scans of the chest, abdomen and pelvis that were obtained for 112 (90.3%) study patients showed no pulmonary emboli, or other thoracic, splanchnic or ileofemoral vein thromboses. Two (1.6%) patients had minor bleeding events that resolved after discontinuation of enoxaparin, requiring neither blood transfusion nor reoperation. The severe complication rate was 5.6%, with no 90-day mortalities. Conclusions These preliminary data suggest that extended pharmacologic thromboprophylaxis for liver surgery patients is safe and effective.

Portal vein embolization improves rate of resection of extensive colorectal liver metastases without worsening survival.

BACKGROUND: Most patients requiring an extended right hepatectomy (ERH) have an inadequate standardized future liver remnant (sFLR) and need preoperative portal vein embolization (PVE). However, the clinical and oncological impact of PVE in such patients remains unclear. METHODS: All consecutive patients presenting at the M. D. Anderson Cancer Center with colorectal liver metastases (CLM) requiring ERH at presentation from 1995 to 2012 were studied. Surgical and oncological outcomes were compared between patients with adequate and inadequate sFLRs at presentation. RESULTS: Of the 265 patients requiring ERH, 126 (47·5 per cent) had an adequate sFLR at presentation, of whom 123 underwent a curative resection. Of the 139 patients (52·5 per cent) who had an inadequate sFLR and underwent PVE, 87 (62·6 per cent) had a curative resection. Thus, the curative resection rate was increased from 46·4 per cent (123 of 265) at baseline to 79·2 per cent (210 of 265) following PVE. Among patients who underwent ERH, major complication and 90-day mortality rates were similar in the no-PVE and PVE groups (22·0 and 4·1 per cent versus 31 and 7 per cent respectively); overall and disease-free survival rates were also similar in these two groups. Of patients with an inadequate sFLR at presentation, those who underwent ERH had a significantly better median overall survival (50·2 months) than patients who had non-curative surgery (21·3 months) or did not undergo surgery (24·7 months) (P = 0·002). CONCLUSION: PVE enabled curative resection in two-thirds of patients with CLM who had an inadequate sFLR and were unable to tolerate ERH at presentation. Patients who underwent curative resection after PVE had overall and disease-free survival rates equivalent to those of patients who did not need PVE.