Decrease in primary but not in secondary abdominal surgery for Crohn's disease: nationwide cohort study, 1990-2014.

BACKGROUND: Treatment of patients with Crohn's disease has evolved in recent decades, with increasing use of immunomodulatory medication since 1990 and biologicals since 1998. In parallel, there has been increased use of active disease monitoring. To what extent these changes have influenced the incidence of primary and repeat surgical resection remains debated. METHODS: In this nationwide cohort study, incident patients of all ages with Crohn's disease, identified in Swedish National Patient Registry between 1990 and 2014, were divided into five calendar periods of diagnosis: 1990-1995 and 1996-2000 with use of inpatient registries, 2001, and 2002-2008 and 2009-2014 with use of inpatient and outpatient registries. The cumulative incidence of first and repeat abdominal surgery (except closure of stomas), by category of surgical procedure, was estimated using the Kaplan-Meier method. RESULTS: Among 21 273 patients with Crohn's disease, the cumulative incidence of first abdominal surgery within 5 years of Crohn's disease diagnosis decreased continuously from 54·8 per cent in 1990-1995 to 40·4 per cent in 1996-2000 (P < 0·001), and again from 19·8 per cent in 2002-2008 to 17·3 per cent in 2009-2014 (P < 0·001). Repeat 5-year surgery rates decreased from 18·9 per cent in 1990-1995 to 16·0 per cent in 1996-2000 (P = 0·009). After 2000, no further significant decreases were observed. CONCLUSION: The 5-year rate of surgical intervention for Crohn's disease has decreased significantly, but the rate of repeat surgery has remained stable despite the introduction of biological therapy.

ANTECEDENTES: El tratamie nto de pacientes con enfermedad de Crohn ha evolucionado en las últimas décadas con un uso cada vez mayor de medicamentos inmunomoduladores desde 1990 y tratamientos biológicos desde 1998. Al mismo tiempo, ha aumentado la utilidad de la vigilancia activa de la enfermedad. Hasta qué punto estos cambios han influido en la incidencia de la resección quirúrgica primaria y repetida sigue siendo objeto de debate. MÉTODOS: Estudio de cohortes a nivel nacional de pacientes incidentes con enfermedad de Crohn de todas las edades identificados en el registro sueco nacional de pacientes entre 1990-2014, que se dividió en cinco períodos de diagnóstico: 1990-1995 y 1996-2000 con el uso de registros de pacientes hospitalizados, 2001, y 2002-2008 y 2009-2014 con uso de registros de pacientes ambulatorios y hospitalizados. Se estimó la incidencia acumulada de la primera cirugía abdominal y de las cirugías abdominales subsiguientes (excepto el cierre de estomas), por categoría de procedimiento quirúrgico, mediante el método de Kaplan-Meier. RESULTADOS: Entre 21.273 pacientes con enfermedad de Crohn, la incidencia acumulada de la primera cirugía abdominal durante los 5 años posteriores al diagnóstico de la enfermedad disminuyó continuamente del 54,8% en la cohorte 1990-1995 al 40,4% en la cohorte 1996-2000 (P < 0,001) y nuevamente del 19,8% en cohorte 2002-2008 al 17,3% en la cohorte 2009-2014 (P < 0,001). Las tasas cirugías iterativas a los 5 años disminuyeron de 18,9% en la cohorte 1990-1995 a 16,0% en la cohorte 1996-2000 (P = 0,017). Después del 2000, no se observaron más disminuciones significativas. CONCLUSIÓN: La tasa de intervención quirúrgica a los 5 años para la enfermedad de Crohn ha disminuido significativamente, pero la cirugía iterativa se ha mantenido estable a pesar de la introducción de la terapia biológica.

From high to low malaria transmission in Zanzibar-challenges and opportunities to achieve elimination.

BACKGROUND: Substantial global progress in the control of malaria in recent years has led to increased commitment to its potential elimination. Whether this is possible in high transmission areas of sub-Saharan Africa remains unclear. Zanzibar represents a unique case study of such attempt, where modern tools and strategies for malaria treatment and vector control have been deployed since 2003. METHODS: We have studied temporal trends of comprehensive malariometric indices in two districts with over 100,000 inhabitants each. The analyses included triangulation of data from annual community-based cross-sectional surveys, health management information systems, vital registry and entomological sentinel surveys. RESULTS: The interventions, with sustained high-community uptake, were temporally associated with a major malaria decline, most pronounced between 2004 and 2007 and followed by a sustained state of low transmission. In 2015, the Plasmodium falciparum community prevalence of 0.43% (95% CI 0.23-0.73) by microscopy or rapid diagnostic test represented 96% reduction compared with that in 2003. The P. falciparum and P. malariae prevalence by PCR was 1.8% (95% CI 1.3-2.3), and the annual P. falciparum incidence was estimated to 8 infections including 2.8 clinical episodes per 1000 inhabitants. The total parasite load decreased over 1000-fold (99.9%) between 2003 and 2015. The incidence of symptomatic malaria at health facilities decreased by 94% with a trend towards relatively higher incidence in age groups > 5 years, a more pronounced seasonality and with reported travel history to/from Tanzania mainland as a higher risk factor. All-cause mortality among children < 5 years decreased by 72% between 2002 and 2007 mainly following the introduction of artemisinin-based combination therapies whereas the main reduction in malaria incidence followed upon the vector control interventions from 2006. Human biting rates decreased by 98% with a major shift towards outdoor biting by Anopheles arabiensis. CONCLUSIONS: Zanzibar provides new evidence of the feasibility of reaching uniquely significant and sustainable malaria reduction (pre-elimination) in a previously high endemic region in sub-Saharan Africa. The data highlight constraints of optimistic prognostic modelling studies. New challenges, mainly with outdoor transmission, a large asymptomatic parasite reservoir and imported infections, require novel tools and reoriented strategies to prevent a rebound effect and achieve elimination.

Childhood onset inflammatory bowel disease and risk of cancer: a Swedish nationwide cohort study 1964-2014.

Objective To assess risk of cancer in patients with childhood onset inflammatory bowel disease in childhood and adulthood.Design Cohort study with matched general population reference individuals using multivariable Cox regression to estimate hazard ratios.Setting Swedish national patient register (both inpatient and non-primary outpatient care) 1964-2014.Participants Incident cases of childhood onset (<18 years) inflammatory bowel disease (n=9405: ulcerative colitis, n=4648; Crohn's disease, n=3768; unclassified, n=989) compared with 92 870 comparators from the general population matched for sex, age, birth year, and county.Main outcome measures Any cancer and cancer types according to the Swedish Cancer Register.Results During follow-up through adulthood (median age at end of follow-up 27 years), 497 (3.3 per 1000 person years) people with childhood onset inflammatory bowel disease had first cancers, compared with 2256 (1.5 per 1000 person years) in the general population comparators (hazard ratio 2.2, 95% confidence interval 2.0 to 2.5). Hazard ratios for any cancer were 2.6 in ulcerative colitis (2.3 to 3.0) and 1.7 in Crohn's disease (1.5 to 2.1). Patients also had an increased risk of cancer before their 18th birthday (2.7, 1.6 to 4.4; 20 cancers in 9405 patients, 0.6 per1000 person years). Gastrointestinal cancers had the highest relative risks, with a hazard ratio of 18.0 (14.4 to 22.7) corresponding to 202 cancers in patients with inflammatory bowel disease. The increased risk of cancer (before 25th birthday) was similar over time (1964-1989: 1.6, 1.0 to 2.4; 1990-2001: 2.3, 1.5 to 3.3); 2002-06: 2.9, 1.9 to 4.2; 2007-14: 2.2, 1.1 to 4.2).Conclusion Childhood onset inflammatory bowel disease is associated with an increased risk of any cancer, especially gastrointestinal cancers, both in childhood and later in life. The higher risk of cancer has not fallen over time.

Statistical controversies in clinical research: assessing pathologic complete response as a trial-level surrogate end point for early-stage breast cancer.

BACKGROUND: A trial-level surrogate end point for a randomized clinical trial may allow assessment of the relative benefits of the treatment to be performed at an earlier time point and potentially with a smaller sample size. However, determining whether an end point is a reliable trial-level surrogate based on results of previous trials is not straightforward. The question of trial-level surrogacy is easily confused with the question of individual-level surrogacy, and this confusion can lead to controversy. A recent example concerns the evaluation of pathologic complete response (pCR) as a surrogate for event-free survival (EFS) and overall survival (OS) in early-stage breast cancer. MATERIALS AND METHODS: The differences between individual-level surrogacy (i.e. for patients receiving a specific treatment, the surrogate end point predicts the definitive end point) and trial-level surrogacy (the results of the trial for the surrogate end point predict the results of the trial for the definitive end point) are discussed. Trial-level data used in two previous meta-analyses evaluating pCR as a trial-level surrogate for EFS and OS were re-analyzed using methods that appropriately account for the variability in pCR rates as well as the variability in the hazard ratios for EFS and OS. RESULTS: There is no evidence that pCR is a trial-level surrogate for EFS or OS, nor is there evidence that pCR could be used reliably to screen out nonpromising agents from further drug development. CONCLUSIONS: At present, neoadjuvant RCTs should continue to follow patients to observe EFS and OS to assess clinical benefit, and they should be designed with sufficient sample size to reliably assess EFS. However, one cannot rule out the possibility that future meta-analyses involving more trials and in which the patient population or class of treatments is restricted could suggest the validity of pCR as a trial-level surrogate for EFS or OS in some focused settings.

Introduction to pion radiotherapy.

In recent years, radiation therapy has seen an influx of experimental treatment beams. The negative pi meson, or pion, is one such beam. It exhibits complex phenomena that may prove to be a major advance in the radiation therapy of some tumors. This paper discusses the pion beam at the Los Alamos Scientific Laboratory, Los Alamos, New Mexico.