IPMN-LEARN: A linear support vector machine learning model for predicting low-grade intraductal papillary mucinous neoplasms.

Backgrounds/Aims: We aimed to build a machine learning tool to help predict low-grade intraductal papillary mucinous neoplasms (IPMNs) in order to avoid unnecessary surgical resection. IPMNs are precursors to pancreatic cancer. Surgical resection remains the only recognized treatment for IPMNs yet carries some risks of morbidity and potential mortality. Existing clinical guidelines are imperfect in distinguishing low-risk cysts from high-risk cysts that warrant resection. Methods: We built a linear support vector machine (SVM) learning model using a prospectively maintained surgical database of patients with resected IPMNs. Input variables included 18 demographic, clinical, and imaging characteristics. The outcome variable was the presence of low-grade or high-grade IPMN based on post-operative pathology results. Data were divided into a training/validation set and a testing set at a ratio of 4:1. Receiver operating characteristics analysis was used to assess classification performance. Results: A total of 575 patients with resected IPMNs were identified. Of them, 53.4% had low-grade disease on final pathology. After classifier training and testing, a linear SVM-based model (IPMN-LEARN) was applied on the validation set. It achieved an accuracy of 77.4%, with a positive predictive value of 83%, a specificity of 72%, and a sensitivity of 83% in predicting low-grade disease in patients with IPMN. The model predicted low-grade lesions with an area under the curve of 0.82. Conclusions: A linear SVM learning model can identify low-grade IPMNs with good sensitivity and specificity. It may be used as a complement to existing guidelines to identify patients who could avoid unnecessary surgical resection.

Uncinate Duct Dilatation Predicts Additional Risk for High-Grade Dysplasia or Invasive Carcinoma Among Fukuoka-Positive Intraductal Papillary Mucinous Neoplasms.

OBJECTIVE: To determine whether uncinate duct dilatation (UDD) increases the risk of high-grade dysplasia or invasive carcinoma (HGD/IC) in Fukuoka-positive intraductal papillary mucinous neoplasms (IPMNs). BACKGROUND: Though classified as a branch duct, the uncinate duct is the primary duct of the pancreatic ventral anlage. We hypothesized that UDD, like main duct dilatation, confers additional risk for HGD/IC. METHODS: A total of 467 patients met inclusion criteria in a retrospective cohort study of surgically resected IPMNs at the Massachusetts General Hospital. We used multivariable logistic regression to analyze the association between UDD (defined as ≥4 mm) and HGD/IC, controlling for Fukuoka risk criteria. In a secondary analysis, the modeling was repeated in the 194 patients with dorsal branch duct IPMNs (BD-IPMNs) in the pancreatic neck, body, or tail. RESULTS: Mean age at surgery was 70, and 229 (49%) patients were female. In total, 267 (57%) patients had only worrisome features and 200 (43%) had at least 1 high-risk feature. UDD was present in 164 (35%) patients, of whom 118 (73%) had HGD/IC. On multivariable analysis, UDD increased the odds of HGD/IC by 2.8-fold, even while controlling for Fukuoka risk factors (95% CI: 1.8-4.4, P <0.001). Prevalence of HGD/IC in all patients with UDD was 73%, compared with 74% in patients with high-risk stigmata and 73% in patients with main duct IPMNs. In the secondary analysis, UDD increased the odds of HGD/IC by 3.2-fold in patients with dorsal BD-IPMNs (95% CI: 1.3-7.7, P =0.010). CONCLUSIONS: UDD confers additional risk for HGD/IC unaccounted for by current Fukuoka criteria. Further research can extend this study to Fukuoka-negative patients, including unresected patients.

Barreras para la eliminación de la malaria en Guapi-Cauca, Colombia / Obstacles to malaria elimination in Guapi-Cauca, Colombia

RESUMEN Objetivo Explicar las barreras para la eliminación de la malaria en Guapi (Cauca, Colombia), según la percepción de la comunidad. Método Se realizó un estudio cualitativo descriptivo de tipo exploratorio en Guapi, de octubre a noviembre de 2016, a través del análisis de contenido de grupos focales de ocho mujeres voluntarias y de análisis inductivo e interpretativo. Resultados Basadas en las respuestas de las voluntarias, se construyeron tres categorías, de las cuales se originaron cinco subcategorías relacionadas con barreras (tema) para la eliminación de la malaria que incluyen determinantes sociales del municipio tales como las barreras ambientales, culturales y de atención en salud. Todas ellas requieren de la intervención integral por parte de las diferentes dependencias del Estado, con la inclusión de las características propias de la comunidad guapireña. Conclusión Se identificó que la falta de planeación e infraestructura deficiente en el municipio obstaculiza no solo la eliminación de la malaria sino también la de otras enfermedades transmisibles. El desarrollo de actividades económicas como la minería, las prácticas de automedicación, la poca adherencia a las medidas de prevención por parte de la comunidad, la falta de contratación de profesionales y microscopistas y el difícil acceso a los servicios de salud constituyen las principales barreras para la eliminación de la malaria en este municipio de la región pacífica colombiana.

ABSTRACT Objetive To explain the obstacles for malaria elimination in Guapi (Cauca, Colombia), considering the community perception. Method A qualitative, descriptive and exploratory research was carried out in Guapi, from October to November 2016, through the content analysis of eight female volunteer's focus groups. Inductive and interpretive analyses were also performed. Results Based on the volunteers' responses, three categories were built, from which five subcategories related to obstacles (issue) for malaria elimination emerged; these included municipality social determinants such as environmental, cultural and health care barriers. All of them require of comprehensive interventions by different state agencies and inclusion of the specific characteristics of the local community. Conclusion We found that lack of planning and municipal poor infrastructure limits the elimination of malaria and other communicable diseases alike. Economic activities such as mining, self-medication practices, community poor adherence to prevention measures, lack of professional and microscopists hiring and the difficulties for accessing to health services are the main obstacles for malaria elimination in this municipality of the Colombian Pacific Coast.

Spatio-temporal dynamics of Plasmodium falciparum transmission within a spatial unit on the Colombian Pacific Coast.

As malaria control programmes concentrate their efforts towards malaria elimination a better understanding of malaria transmission patterns at fine spatial resolution units becomes necessary. Defining spatial units that consider transmission heterogeneity, human movement and migration will help to set up achievable malaria elimination milestones and guide the creation of efficient operational administrative control units. Using a combination of genetic and epidemiological data we defined a malaria transmission unit as the area contributing 95% of malaria cases diagnosed at the catchment facility located in the town of Guapi in the South Pacific Coast of Colombia. We provide data showing that P. falciparum malaria transmission is heterogeneous in time and space and analysed, using topological data analysis, the spatial connectivity, at the micro epidemiological level, between parasite populations circulating within the unit. To illustrate the necessity to evaluate the efficacy of malaria control measures within the transmission unit in order to increase the efficiency of the malaria control effort, we provide information on the size of the asymptomatic reservoir, the nature of parasite genotypes associated with drug resistance as well as the frequency of the Pfhrp2/3 deletion associated with false negatives when using Rapid Diagnostic Tests.

[Obstacles to malaria elimination in Guapi-Cauca, Colombia]. / Barreras para la eliminación de la malaria en Guapi-Cauca, Colombia.

OBJETIVE: To explain the obstacles for malaria elimination in Guapi (Cauca, Colombia), considering the community perception. METHOD: A qualitative, descriptive and exploratory research was carried out in Guapi, from October to November 2016, through the content analysis of eight female volunteer's focus groups. Inductive and interpretive analyses were also performed. RESULTS: Based on the volunteers' responses, three categories were built, from which five subcategories related to obstacles (issue) for malaria elimination emerged; these included municipality social determinants such as environmental, cultural and health care barriers. All of them require of comprehensive interventions by different state agencies and inclusion of the specific characteristics of the local community. CONCLUSION: We found that lack of planning and municipal poor infrastructure limits the elimination of malaria and other communicable diseases alike. Economic activities such as mining, self-medication practices, community poor adherence to prevention measures, lack of professional and microscopists hiring and the difficulties for accessing to health services are the main obstacles for malaria elimination in this municipality of the Colombian Pacific Coast.

OBJETIVO: Explicar las barreras para la eliminación de la malaria en Guapi (Cauca, Colombia), según la percepción de la comunidad. MÉTODO: Se realizó un estudio cualitativo descriptivo de tipo exploratorio en Guapi, de octubre a noviembre de 2016, a través del análisis de contenido de grupos focales de ocho mujeres voluntarias y de análisis inductivo e interpretativo. RESULTADOS: Basadas en las respuestas de las voluntarias, se construyeron tres categorías, de las cuales se originaron cinco subcategorías relacionadas con barreras (tema) para la eliminación de la malaria que incluyen determinantes sociales del municipio tales como las barreras ambientales, culturales y de atención en salud. Todas ellas requieren de la intervención integral por parte de las diferentes dependencias del Estado, con la inclusión de las características propias de la comunidad guapireña. CONCLUSIÓN: Se identificó que la falta de planeación e infraestructura deficiente en el municipio obstaculiza no solo la eliminación de la malaria sino también la de otras enfermedades transmisibles. El desarrollo de actividades económicas como la minería, las prácticas de automedicación, la poca adherencia a las medidas de prevención por parte de la comunidad, la falta de contratación de profesionales y microscopistas y el difícil acceso a los servicios de salud constituyen las principales barreras para la eliminación de la malaria en este municipio de la región pacífica colombiana.

Estrategias para la eliminación de malaria: una perspectiva afro-colombiana / Strategies for malaria elimination: an Afro-Colombian perspective

RESUMEN Objetivo Describir las estrategias para la eliminación de la malaria a partir de la percepción de pobladores afro-colombianos residentes en Guapi en el contexto de la Estrategia de Gestión Integrada para la promoción, prevención y control de las Enfermedades Transmitidas por Vectores en Colombia (EGI). Métodos Estudio de tipo cualitativo basado en el análisis de discurso de grupos focales. Ocho participantes residentes en zona urbana de Guapi, divididas en dos grupos: el primero correspondió a tres mujeres auxiliares de enfermería, denominadas "mujeres con mayor experiencia", trabajadoras en el actual sistema de salud y funcionarias del antiguo Servicio de Erradicación de la Malaria. El segundo correspondió a cinco mujeres auxiliares de enfermería, denominadas "mujeres con limitada experiencia", trabajadoras en el actual sistema de salud y no tuvieron formación directa con el programa de malaria. Análisis inductivo e interpretativo. Resultados Emergieron ocho subcategorias enmarcadas en la EGI, con énfasis en la promoción y prevención orientadas a disminuir la malaria, especialmente en el área rural. El abordaje del problema debe hacerse de forma integral incluyendo otras problemáticas en salud y determinantes sociales que los afectan como: saneamiento básico, acceso al servicio de salud, falta de educación, uso de tratamientos populares, fragilidad de infraestructura, entre otros. Conclusión Las participantes consideran que la malaria en Guapi se puede reducir pero no eliminar. Se requiere abordar este problema desde una perspectiva institucional y comunitaria, teniendo en cuenta las diferencias culturales, a partir de estrategias que incluyan el empoderamiento comunitario y fortalecimiento administrativo e institucional del programa.(AU)

ABSTRACT Objective To describe strategies for malaria elimination based on the perception of Afro-Colombian residents in Guapi, in the context of the Integrated Management Strategy for the Promotion, Prevention and Control of Vector-Borne Diseases in Colombia (EGI-ETV). Materials and Methods Qualitative study based on focus group discourse analysis. Eight participants from the urban area of Guapi were divided into two groups. The first group included three female nursing assistants, and was called "women with more experience"; they were workers in the current health system and former Malaria Eradication Service officers. The second group was made up of female nursing assistants, and was called "women with limited experience"; they were workers in the current health system and were not directly trained in the malaria program. An inductive and interpretative analysis was performed. Results Eight subcategories emerged, framed in the EGI-EVT, making emphasis on promotion and prevention aimed at reducing malaria, especially in rural areas. This problem must be addressed comprehensively, including other health issues and social determinants that affect them, such as: basic sanitation, access to health services, lack of education, use of popular treatments, and lack of infrastructure, among others. Conclusion Participants consider that malaria in Guapi can be reduced but not eliminated. This problem needs to be addressed from an institutional and community perspective, taking into account cultural differences, based on strategies that include community empowerment and administrative and institutional strengthening of the program.(AU)

[Strategies for malaria elimination: an Afro-Colombian perspective]. / Estrategias para la eliminación de malaria: una perspectiva afro-colombiana.

OBJECTIVE: To describe strategies for malaria elimination based on the perception of Afro-Colombian residents in Guapi, in the context of the Integrated Management Strategy for the Promotion, Prevention and Control of Vector-Borne Diseases in Colombia (EGI-ETV). MATERIALS AND METHODS: Qualitative study based on focus group discourse analysis. Eight participants from the urban area of Guapi were divided into two groups. The first group included three female nursing assistants, and was called "women with more experience"; they were workers in the current health system and former Malaria Eradication Service officers. The second group was made up of female nursing assistants, and was called "women with limited experience"; they were workers in the current health system and were not directly trained in the malaria program. An inductive and interpretative analysis was performed. RESULTS: Eight subcategories emerged, framed in the EGI-EVT, making emphasis on promotion and prevention aimed at reducing malaria, especially in rural areas. This problem must be addressed comprehensively, including other health issues and social determinants that affect them, such as: basic sanitation, access to health services, lack of education, use of popular treatments, and lack of infrastructure, among others. CONCLUSION: Participants consider that malaria in Guapi can be reduced but not eliminated. This problem needs to be addressed from an institutional and community perspective, taking into account cultural differences, based on strategies that include community empowerment and administrative and institutional strengthening of the program.

OBJETIVO: Describir las estrategias para la eliminación de la malaria a partir de la percepción de pobladores afro-colombianos residentes en Guapi en el contexto de la Estrategia de Gestión Integrada para la promoción, prevención y control de las Enfermedades Transmitidas por Vectores en Colombia (EGI). MÉTODOS: Estudio de tipo cualitativo basado en el análisis de discurso de grupos focales. Ocho participantes residentes en zona urbana de Guapi, divididas en dos grupos: el primero correspondió a tres mujeres auxiliares de enfermería, denominadas "mujeres con mayor experiencia", trabajadoras en el actual sistema de salud y funcionarias del antiguo Servicio de Erradicación de la Malaria. El segundo correspondió a cinco mujeres auxiliares de enfermería, denominadas "mujeres con limitada experiencia", trabajadoras en el actual sistema de salud y no tuvieron formación directa con el programa de malaria. Análisis inductivo e interpretativo. RESULTADOS: Emergieron ocho subcategorias enmarcadas en la EGI, con énfasis en la promoción y prevención orientadas a disminuir la malaria, especialmente en el área rural. El abordaje del problema debe hacerse de forma integral incluyendo otras problemáticas en salud y determinantes sociales que los afectan como: saneamiento básico, acceso al servicio de salud, falta de educación, uso de tratamientos populares, fragilidad de infraestructura, entre otros. CONCLUSIÓN: Las participantes consideran que la malaria en Guapi se puede reducir pero no eliminar. Se requiere abordar este problema desde una perspectiva institucional y comunitaria, teniendo en cuenta las diferencias culturales, a partir de estrategias que incluyan el empoderamiento comunitario y fortalecimiento administrativo e institucional del programa.

Branch duct intraductal papillary mucinous neoplasms: does cyst size change the tip of the scale? A critical analysis of the revised international consensus guidelines in a large single-institutional series.

OBJECTIVE: The aim of this study was to critically analyze the safety of the revised guidelines, with focus on cyst size and worrisome features in the management of BD-IPMN. BACKGROUND: The Sendai guidelines for management of branch duct (BD) intraductal papillary mucinous neoplasm (IPMN) espouse safety of observation of asymptomatic cysts smaller than 3 cm without nodules (Sendai negative). Revised international consensus guidelines published in 2012 suggest a still more conservative approach, even for lesions of 3 cm or larger. By contrast, 2 recent studies have challenged the safety of both guidelines, describing invasive carcinoma or carcinoma in situ in 67% of BD-IPMN smaller than 3 cm and in 25% of "Sendai-negative" BD-IPMN. METHODS AND RESULTS: Review of a prospective database identified 563 patients with BD-IPMN. A total of 240 patients underwent surgical resection (152 at the time of diagnosis and 88 after being initially followed); the remaining 323 have been managed by observation with median follow-up of 60 months. No patient developed unresectable BD-IPMN carcinoma during follow-up. Invasive cancer arising in BD-IPMN was found in 23 patients of the entire cohort (4%), and an additional 21 patients (3.7%) had or developed concurrent pancreatic ductal adenocarcinoma. According to the revised guidelines, 76% of resected BD-IPMN with carcinoma in situ and 95% of resected BD-IPMN with invasive cancer had high-risk stigmata or worrisome features. The risk of high-grade dysplasia in nonworrisome lesions smaller than 3 cm was 6.5%, but when the threshold was raised to greater than 3 cm, it was 8.8%, and 1 case of invasive carcinoma was found. CONCLUSIONS: Expectant management of BD-IPMN following the old guidelines is safe, whereas caution is advised for larger lesions, even in the absence of worrisome features.