Differentiating autoimmune pancreatitis from pancreatic ductal adenocarcinoma with CT radiomics features.

PURPOSE: The purpose of this study was to determine whether computed tomography (CT)-based machine learning of radiomics features could help distinguish autoimmune pancreatitis (AIP) from pancreatic ductal adenocarcinoma (PDAC). MATERIALS AND METHODS: Eighty-nine patients with AIP (65 men, 24 women; mean age, 59.7±13.9 [SD] years; range: 21-83 years) and 93 patients with PDAC (68 men, 25 women; mean age, 60.1±12.3 [SD] years; range: 36-86 years) were retrospectively included. All patients had dedicated dual-phase pancreatic protocol CT between 2004 and 2018. Thin-slice images (0.75/0.5mm thickness/increment) were compared with thick-slices images (3 or 5mm thickness/increment). Pancreatic regions involved by PDAC or AIP (areas of enlargement, altered enhancement, effacement of pancreatic duct) as well as uninvolved parenchyma were segmented as three-dimensional volumes. Four hundred and thirty-one radiomics features were extracted and a random forest was used to distinguish AIP from PDAC. CT data of 60 AIP and 60 PDAC patients were used for training and those of 29 AIP and 33 PDAC independent patients were used for testing. RESULTS: The pancreas was diffusely involved in 37 (37/89; 41.6%) patients with AIP and not diffusely in 52 (52/89; 58.4%) patients. Using machine learning, 95.2% (59/62; 95% confidence interval [CI]: 89.8-100%), 83.9% (52:67; 95% CI: 74.7-93.0%) and 77.4% (48/62; 95% CI: 67.0-87.8%) of the 62 test patients were correctly classified as either having PDAC or AIP with thin-slice venous phase, thin-slice arterial phase, and thick-slice venous phase CT, respectively. Three of the 29 patients with AIP (3/29; 10.3%) were incorrectly classified as having PDAC but all 33 patients with PDAC (33/33; 100%) were correctly classified with thin-slice venous phase with 89.7% sensitivity (26/29; 95% CI: 78.6-100%) and 100% specificity (33/33; 95% CI: 93-100%) for the diagnosis of AIP, 95.2% accuracy (59/62; 95% CI: 89.8-100%) and area under the curve of 0.975 (95% CI: 0.936-1.0). CONCLUSIONS: Radiomic features help differentiate AIP from PDAC with an overall accuracy of 95.2%.

Validation of a nomogram to predict the risk of cancer in patients with intraductal papillary mucinous neoplasm and main duct dilatation of 10 mm or less.

BACKGROUND: Intraductal papillary mucinous neoplasm (IPMN) is premalignant pancreatic lesion. International guidelines offer limited predictors of individual risk. A nomogram to predict individual IPMN malignancy risk was released, with good diagnostic performance based on a large cohort of Asian patients with IPMN. The present study validated a nomogram to predict malignancy risk and invasiveness of IPMN using both Eastern and Western cohorts. METHODS: Clinicopathological and radiological data from patients who underwent pancreatic resection for IPMN at four centres each in Eastern and Western countries were collected. After excluding patients with missing data for at least one malignancy predictor in the nomogram (main pancreatic duct diameter, cyst size, presence of mural nodule, serum carcinoembryonic antigen and carbohydrate antigen (CA) 19-9 levels, and age). RESULTS: In total, data from 393 patients who fit the criteria were analysed, of whom 265 were from Eastern and 128 from Western institutions. Although mean age, sex, log value of serum CA19-9 level, tumour location, main duct diameter, cyst size and presence of mural nodule differed between the Korean/Japanese, Eastern and Western cohorts, rates of malignancy and invasive cancer did not differ significantly. Areas under the receiver operating characteristic (ROC) curve values for the nomogram predicting malignancy were 0·745 for Eastern, 0·856 for Western and 0·776 for combined cohorts; respective values for the nomogram predicting invasiveness were 0·736, 0·891 and 0·788. CONCLUSIONS: External validation of the nomogram showed good performance in predicting cancer in both Eastern and Western patients with IPMN lesions.

ANTECEDENTES: La neoplasia mucinosa papilar intraductal (intraductal papillary mucinous neoplasm, IPMN) es una lesión pancreática premaligna. Las guías internacionales incluyen un número limitado de factores predictivos de riesgo individual. Para predecir el riesgo individual de malignidad del IPMN se ha propuesto un nomograma con un buen rendimiento diagnóstico, basado en una gran cohorte de pacientes asiáticos con IPMN. Este estudio validó el nomograma para predecir el riesgo de cáncer y de invasión de la IPMN utilizando cohortes tanto orientales como occidentales. MÉTODOS: Se recogieron datos clínico-patológicos y radiológicos de pacientes en los que se realizó una resección de páncreas por IPMN en 4 centros en países orientales y en 4 centros de países occidentales. Se excluyeron los pacientes en los que en el nomograma faltaba ≥ 1 factor(es) predictivo(s) de malignidad (diámetro del conducto pancreático principal, tamaño del quiste, presencia de nódulo mural, niveles séricos de CEA y CA19-9, y edad). RESULTADOS: En total, se analizaron datos de 393 pacientes que cumplían con los criterios de inclusión, de los cuales 265 eran de centros orientales y 128 de centros occidentales. Aunque la edad media, el sexo, el valor logarítmico del nivel sérico de CA19-9, la localización del tumor, el diámetro del conducto principal, el tamaño del quiste y la presencia de un nódulo mural difirieron entre las cohortes de Corea/Japón y las cohortes oriental y occidental, las tasas de malignidad y de cáncer invasivo no fueron significativamente diferentes. Las áreas bajo la curva operativa del receptor (area under the receiver operating curve, AUC) que mostró el nomograma para predecir la malignidad fueron: cohorte oriental: 0,745; cohorte occidental: 0,856 y cohortes combinadas: 0,776; y para predecir la invasión tumoral fueron: cohorte oriental: 0,736; cohorte occidental: 0,891, y cohortes combinadas: 0,788. CONCLUSIÓN: La validación externa del nomograma mostró un buen rendimiento en la predicción de cáncer, tanto en pacientes orientales como occidentales con lesiones IPMN.

Perioperative outcomes and long-term quality of life after total pancreatectomy.

BACKGROUND: Total pancreatectomy is required to treat diseases involving the entire pancreas, and is characterized by high morbidity rates and impaired long-term quality of life (QoL). To date, risk factors associated with perioperative and long-term outcomes have not been determined fully. METHODS: Data from patients undergoing total pancreatectomy between 2000 and 2014 at two high-volume centres were analysed retrospectively to assess risk factors for major surgical complications. Short Form (SF) 36, European Organisation for Research and Treatment of Cancer QLQ-PAN26 and Audit of Diabetes Dependent questionnaires, as well as an original survey were used to investigate factors influencing QoL. RESULTS: A total of 329 consecutive patients underwent total pancreatectomy in the two centres. Overall, total pancreatectomy was associated with a morbidity rate of 59·3 per cent and a 30-day mortality rate of 2·1 per cent. Age over 65 years and long duration of surgery (more than 420 min) were independently associated with major complications (at least Clavien-Dindo grade III). QoL analysis was available for 94 patients (28·6 per cent) with a median follow-up of 63 (i.q.r. 20-109) months; the most common indication for total pancreatectomy in these patients was intraductal papillary mucinous neoplasms (46 per cent). Both physical (PCS) and mental (MCS) component summary scores of SF-36® were lower after total pancreatectomy compared with scores for a normative population (P = 0·020 and P < 0·001 respectively). Linear regression analysis showed that young age, abdominal pain and worse perception of body image were negatively associated with the PCS, whereas diabetes, sexual satisfaction and perception of body image affected MCS. CONCLUSION: Total pancreatectomy can be performed with acceptable morbidity and mortality rates. Older patients had a higher risk of postoperative complications but reported better QoL than younger patients.

ANTECEDENTES: La pancreatectomía total es una cirugía necesaria para tratar enfermedades que afectan a la totalidad el páncreas y se caracteriza por una alta morbilidad y una disminución de la calidad de vida (QoL) a largo plazo. Hasta la fecha, los factores de riesgo asociados a los resultados perioperatorios y a largo plazo no han sido completamente determinados. MÉTODOS: Los datos de los pacientes que se sometieron a una pancreatectomía total desde el año 2000 al 2015 en dos centros de alto volumen se analizaron retrospectivamente para evaluar los factores de riesgo de las complicaciones quirúrgicas mayores. Se utilizaron el SF-36, el EORTC-PAN-26, los cuestionarios ADD-QoL y una encuesta original para investigar los factores que afectan la QoL. RESULTADOS: Un total de 329 pacientes consecutivos se sometieron a una pancreatectomía total en los dos centros. En general, la pancreatectomía total se asoció a un 59,3% de morbilidad y un 2,1% de mortalidad a los 30 días. La edad > 65 años y el tiempo operatorio prolongado (> 420 minutos) se asociaron de forma independiente a las complicaciones Clavien-Dindo ≥ III. El análisis de QoL estuvo disponible en 94 (28,6%) de los pacientes con una mediana de seguimiento de 63 meses (rango intercuartílico 20-109) y la indicación más común fue una neoplasia papilar mucinosa intraductal (IPMN) (45,7%). Las puntuaciones del SF-36 fueron más bajas en ambos componentes sumatorios físico (PCS) y mental (MCS) (P = 0,002; P < 0,001) en comparación con una población normal. El modelo de regresión lineal mostró que la edad joven, el dolor abdominal y la peor percepción de la imagen corporal se asociaron negativamente con el PCS; mientras que la diabetes, la satisfacción sexual y la percepción de la imagen corporal afectaron al MCS. CONCLUSIÓN: Se puede realizar una pancreatectomía total con morbilidad y mortalidad aceptables. Los pacientes de mayor edad tienen un riesgo más elevado de complicaciones postoperatorias, pero presentaron mejor QoL que los pacientes más jóvenes.

Circulating tumor DNA as a potential marker of adjuvant chemotherapy benefit following surgery for localized pancreatic cancer.

BACKGROUND: In early-stage pancreatic cancer, there are currently no biomarkers to guide selection of therapeutic options. This prospective biomarker trial evaluated the feasibility and potential clinical utility of circulating tumor DNA (ctDNA) analysis to inform adjuvant therapy decision making. MATERIALS AND METHODS: Patients considered by the multidisciplinary team to have resectable pancreatic adenocarcinoma were enrolled. Pre- and post-operative samples for ctDNA analysis were collected. PCR-based-SafeSeqS assays were used to identify mutations at codon 12, 13 and 61 of KRAS in the primary pancreatic tumor and to detect ctDNA. Results of ctDNA analysis were correlated with CA19-9, recurrence-free and overall survival (OS). Patient management was per standard of care, blinded to ctDNA data. RESULTS: Of 112 patients consented pre-operatively, 81 (72%) underwent resection. KRAS mutations were identified in 91% (38/42) of available tumor samples. Of available plasma samples (N = 42), KRAS mutated ctDNA was detected in 62% (23/37) pre-operative and 37% (13/35) post-operative cases. At a median follow-up of 38.4 months, ctDNA detection in the pre-operative setting was associated with inferior recurrence-free survival (RFS) [hazard ratio (HR) 4.1; P = 0.002)] and OS (HR 4.1; P = 0.015). Detectable ctDNA following curative intent resection was associated with inferior RFS (HR 5.4; P < 0.0001) and OS (HR 4.0; P = 0.003). Recurrence occurred in 13/13 (100%) patients with detectable ctDNA post-operatively, including in seven that received gemcitabine-based adjuvant chemotherapy. CONCLUSION: ctDNA studies in localized pancreatic cancer are challenging, with a substantial number of patients not able to undergo resection, not having sufficient tumor tissue for analysis or not completing per protocol sample collection. ctDNA analysis, pre- and/or post-surgery, is a promising prognostic marker. Studies of ctDNA guided therapy are justified, including of treatment intensification strategies for patients with detectable ctDNA post-operatively who appear at very high risk of recurrence despite gemcitabine-based adjuvant therapy.

Genetic And Morphological Evaluation (GAME) score for patients with colorectal liver metastases.

BACKGROUND: This study sought to develop a clinical risk score for resectable colorectal liver metastasis (CRLM) by combining clinicopathological and clinically available biological indicators, including KRAS. METHODS: A cohort of patients who underwent resection for CRLM at the Johns Hopkins Hospital (JHH) was analysed to identify independent predictors of overall survival (OS) that can be assessed before operation; these factors were combined into the Genetic And Morphological Evaluation (GAME) score. The score was compared with the current standard (Fong score) and validated in an external cohort of patients from the Memorial Sloan Kettering Cancer Center (MSKCC). RESULTS: Six preoperative predictors of worse OS were identified on multivariable Cox regression analysis in the JHH cohort (502 patients). The GAME score was calculated by allocating points to each patient according to the presence of these predictive factors: KRAS-mutated tumours (1 point); carcinoembryonic antigen level 20 ng/ml or more (1 point), primary tumour lymph node metastasis (1 point); Tumour Burden Score between 3 and 8 (1 point) or 9 and over (2 points); and extrahepatic disease (2 points). The high-risk group in the JHH cohort (GAME score at least 4 points) had a 5-year OS rate of 11 per cent, compared with 73·4 per cent for those in the low-risk group (score 0-1 point). Importantly, in cohorts from both the JHH and MSKCC (747 patients), the discriminatory capacity of the GAME score was superior to that of the Fong score, as demonstrated by the C-index and the Akaike information criterion. CONCLUSION: The GAME score is a preoperative prognostic tool that can be used to inform treatment selection.

Laparoscopic pancreatic surgery.

Laparoscopic pancreatectomy may be associated with lower operative morbidity, less postoperative pain, lower wound infection rates, decreased physiological stress, and fewer postoperative hernias and bowel obstructions. In this review, we summarize the current data on laparoscopic and robotic assisted pancreaticoduodenectomy/distal pancreatectomy/central pancreatectomy. We reviewed the indications, the perioperative and oncologic outcomes, and the cost analysis following minimally invasive pancreatic resections. In conclusion, we found minimally invasive approaches to pancreatic resections are feasible, safe, and appear to have comparable oncologic outcomes to the standard open approaches when performed by experienced surgeons at high-volume centers. The potential advantages of a minimally invasive approach to pancreatic surgery, such as reduced blood loss and shorter length of hospital stay, have now been well established. The overall cost of laparoscopic pancreatectomy appears to be similar to that of the open approach.

Resection of isolated renal cell carcinoma metastases of the pancreas: outcomes from the Johns Hopkins Hospital.

PURPOSE: This study aims to assess outcomes and characteristics associated with resection of metastatic renal cell carcinoma (mRCC) to the pancreas. MATERIALS AND METHODS: From April 1989 to July 2012, a total of 42 patients underwent resection of pancreatic mRCC at our institution. We retrospectively reviewed records from a prospectively managed database and analyzed patient demographics, comorbidities, perioperative outcomes, and overall survival. Cox proportional hazards models were used to evaluate the association between patient-specific factors and overall survival. RESULTS: The mean time from resection of the primary tumor to reoperation for pancreatic mRCC was 11.2 years (range, 0-28.0 years). In total, 17 patients underwent pancreaticoduodenectomy, 16 underwent distal pancreatectomy, and 9 underwent total pancreatectomy. Perioperative complications occurred in 18 (42.9%) patients; there were two (4.8%) perioperative mortalities. After pancreatic resection, the median follow-up was 7.0 years (0.1-23.2 years), and median survival was 5.5 years (range, 0.4-21.9). The overall 5-year survival was 51.8%. On univariate analysis, vascular invasion (hazard ratio, 5.15; p = 0.005) was significantly associated with increased risk of death. CONCLUSIONS: Pancreatic resection of mRCC can be safely achieved in the majority of cases and is associated with long-term survival. Specific pathological factors may predict which patients will benefit most from resection.

Arg278, but not Lys229 or Lys236, plays an important role in the binding of retinoic acid by retinoic acid receptor gamma.

The diverse biological actions of retinoic acid (RA) are mediated by retinoic acid receptors (RARalpha, beta and gamma) and retinoid X receptors (RXR alpha, beta, and gamma). Although the ligand-binding domains of RARs share the same novel folding pattern, many RAR subtype-specific retinoids have been synthesized indicating that the ligand-binding pocket of each RAR subtype has unique features. Previously we have demonstrated the importance for RA binding and RA-dependent transactivation of Arg276 of RARalpha alone and in RARbeta Arg269 in conjunction with Lys220. In this study, we have examined the role of the homologous amino acid residues (Lys229 and Arg278) in RARgamma for these activities. Like RARalpha but dissimilar to RARbeta, Arg278 in RARgamma alone was found to play an important role in RA binding and RA-dependent transactivation. Since Lys236 in RARgamma was suggested from the crystal structure of holo-RARgamma to interact with RA, we also examined its role and that of its homologs in RARalpha and RARbeta. Despite the suggestion from the crystal structure, neither Lys236 nor its homologs in RARalpha and RARbeta play a role in the binding of RA or RA-dependent transactivation. It is likely that Lys236 in RARgamma and its homologs in RARalpha and RARbeta are solvent exposed rather than pointing into the RA-binding pocket.

Differential role of homologous positively charged amino acid residues for ligand binding in retinoic acid receptor alpha compared with retinoic acid receptor beta.

The diverse biological actions of retinoic acid (RA) are mediated by retinoic acid receptors (RARs) and retinoid X receptors. Although it has been suggested that the ligand binding domains (LBDs) of RARs share the same novel folding pattern, many RAR subtype-specific agonists and antagonists have been synthesized demonstrating that the LBD of each RAR subtype has unique features. We have examined the role of several positively charged amino acid residues located in the LBD of RARalpha in RA binding. These results are compared with previously published data for the homologous mutations in RARbeta. Lys227 of RARalpha does not appear to be important for RA binding or RA-dependent transactivation, whereas the homologous residue in RARbeta, Lys220, plays an important synergistic role with Arg269 in these two activities. In addition, Arg276 of RARalpha, like its homologous residue Arg269 of RARbeta, was found to play an important role in the binding of RA most likely by interacting with the carboxylate group of RA. However, the orientation of and electronic environment associated with Arg276 in RARalpha appears to be different from that of Arg269 in RARbeta, thus contributing to the uniqueness of the ligand binding pocket of each receptor.

Identification of sulfhydryl-modified cysteine residues in the ligand binding pocket of retinoic acid receptor beta.

The diverse biological functions of retinoic acid (RA) are mediated through retinoic acid receptors (RARs) and retinoid X receptors. RARs contain a high affinity binding site for RA which is sensitive to treatment with sulfhydryl modification reagents. In an attempt to identify which Cys residues are important for this loss of binding, we created three site-specific RARbeta mutants: C228A, C258A, and C267A. The affinity for RA of all three mutant receptors was in the range of that of the wild type protein, suggesting that none of these Cys residues are critical for RA binding. Rather, these modified Cys residue(s) function to sterically hinder RA binding; however, the modified Cys residues critical for the inhibition of binding differ depending on the reagent employed. Only modification of Cys228 is necessary to inhibit RA binding when RARbeta is modified by reagents which transfer large bulky groups while both Cys228 and Cys267 must be modified when a small functional group is transferred. These data suggest that both Cys228 and Cys267 but not Cys258 lie in the ligand binding pocket of RARbeta. However, Cys228 lies closer to the opening of the RARbeta ligand binding pocket whereas Cys267 lies more deeply buried.