Combining data to perform population-based observational studies: know your sources. The case of thyroid cancer in Belgium.

BACKGROUND: Large scale observational studies are crucial to study thyroid cancer incidence and management, known to vary in time and place. Combining cancer registry data with other data sources enables execution of population-based studies, provided data sources are accurate. The objective was to compare thyroid tumour and treatment information between the available data sources in Belgium. METHODS: We performed a retrospective national population-based cohort study. All patients with thyroid cancer diagnosis in Belgium between 2009 and 2011 (N = 2659 patients) were retrieved from the Belgian Cancer Registry database, containing standard patient and tumour characteristics. Additionally, information was obtained from the following sources: a) detailed pathology reports b) the health insurance company database for reimbursed performed therapeutic acts (both available for N = 2400 patients) c) registration forms for performed and/or planned treatments at the time of the multidisciplinary team meeting (available for N = 1819 patients). More precisely, information was retrieved regarding characteristics of the tumour (histologic subtype, tumour size, lymph node status (source a)) and the treatment (thyroid surgery (a,b,c), lymph node dissection (a,b), postoperative administration of radioactive iodine (b,c)). RESULTS: High concordance in histological cancer subtype (> 90%), tumour size (96.2%) and lymph node involvement (89.2%) categories was found between the cancer registry database and the pathology reports. Tumour subcategories (such as microcarcinoma, tumor ≤1 cm diameter) were more specified in the pathology reports. The therapeutic act of thyroid surgery as mentioned in the pathology reports and health insurance company database was concordant in 92.7%, while reports from multidisciplinary team meetings showed 88.5% of concordance with pathology reports and 86.1% with health insurance data. With regard to postoperative radioiodine administration, reports from multidisciplinary teams and health insurance data were concordant in 76.8%. CONCLUSION: Combining registered and/or administrative data results in sufficiently accurate information to perform large scale observational studies on thyroid cancer in Belgium. However, thorough and continuous quality control and insight in strengths and limitations of each cancer data source is crucial.

Evolution in the management of thyroid cancer: an observational study in two referral centres in Belgium.

Objective Thyroid cancer incidence is increasing. The rise is most pronounced for microcancers (≤10 mm, T1a). In 2006, landmark European and American guidelines for the management of thyroid cancer were published. We studied thyroid cancer characteristics and initial management before and after 2006. Methods We conducted a retrospective observational study of non-medullary thyroid cancer patients that underwent thyroidectomy in two Belgian referral centres comparing pre-, per- and post-operative management in a cohort before and after 2006. Results Cancer subtypes and dimensions in cohort 1 (C1, n = 69) and cohort 2 (C2, n = 60) were comparable, with papillary thyroid cancer (PTC) as main subtype (86 and 82%, respectively), and T1a as main dimension (30 and 38%). In C2, a comparable proportion presented as incidentaloma (20 vs. 14% in C1). Pre-surgical fine needle aspiration (FNA) was performed in 75% in C1 and 83% in C2. The indications for thyroidectomy were comparable, with Bethesda 5-6 as main indication (43% in C1, 52% in C2). No differences were observed for execution of lymph node dissection in the PTC subgroup, hypoparathyroidism and recurrent nerve paresis after 1 year. Less radioiodine was administered in C2 (57 vs 74% in C1, p = 0.04). More neck ultrasonography at 1 year was performed in >T1aN0/x patients (73 vs 49% in C1, p = 0.02). Conclusion The use of FNA is high and established. The proportion of T1a cancers is stable. A shift in the post-operative management is observed towards more restrictive use of radioiodine and increased use of ultrasonography, in accordance with the international guidelines.

Sodium glucose transporter protein 2 inhibitors: focusing on the kidney to treat type 2 diabetes.

Type 2 diabetes mellitus (T2DM) is increasing worldwide. Treatment of T2DM continues to present challenges, with a significant proportion of patients failing to achieve and maintain glycemic targets. Despite the availability of many oral antidiabetic agents, therapeutic efficacy is also offset by side effects such as weight gain and hypoglycemia. Therefore, the search for novel therapeutic agents with an improved benefit-risk profile continues. In the following review we focus on a novel class of oral antidiabetic drugs, the sodium glucose transporter protein 2 (SGLT2) inhibitors, which have unique characteristics. SGLT2 inhibitors focus on the kidney as a therapeutic target, where they inhibit the reabsorption of glucose in the proximal tubule, causing an increase in urinary glucose excretion. Doing this, they reduce plasma glucose independently of the ß-cell function of the pancreas. SGLT2 inhibitors are effective at lowering hemoglobin A1c, but also induce weight loss and reduce blood pressure, with a low risk of hypoglycemia. In general, the SGLT2 inhibitors are well tolerated, with the most frequent adverse events being mild urinal and genital infections. Since their primary site of effect is the kidney, these drugs are less effective in patients with impaired kidney function but evidence is emerging that these drugs may also have a protective effect against diabetic nephropathy. This review focuses on the most extensively studied SGLT2 inhibitors dapagliflozin, canagliflozin and empagliflozin. Dapagliflozin and canagliflozin have already been approved for marketing by the US Food and Drug Administration. The European Medicines Agency has accepted all three drugs for marketing.

Two distinct chronic obstructive pulmonary disease (COPD) phenotypes are associated with high risk of mortality.

RATIONALE: In COPD patients, mortality risk is influenced by age, severity of respiratory disease, and comorbidities. With an unbiased statistical approach we sought to identify clusters of COPD patients and to examine their mortality risk. METHODS: Stable COPD subjects (n = 527) were classified using hierarchical cluster analysis of clinical, functional and imaging data. The relevance of this classification was validated using prospective follow-up of mortality. RESULTS: The most relevant patient classification was that based on three clusters (phenotypes). Phenotype 1 included subjects at very low risk of mortality, who had mild respiratory disease and low rates of comorbidities. Phenotype 2 and 3 were at high risk of mortality. Phenotype 2 included younger subjects with severe airflow limitation, emphysema and hyperinflation, low body mass index, and low rates of cardiovascular comorbidities. Phenotype 3 included older subjects with less severe respiratory disease, but higher rates of obesity and cardiovascular comorbidities. Mortality was associated with the severity of airflow limitation in Phenotype 2 but not in Phenotype 3 subjects, and subjects in Phenotype 2 died at younger age. CONCLUSIONS: We identified three COPD phenotypes, including two phenotypes with high risk of mortality. Subjects within these phenotypes may require different therapeutic interventions to improve their outcome.