Christoffer Holst Hahn

Papillary thyroid carcinoma in Denmark, 1996-2008

BACKGROUND Regional as well as national series show an increasing incidence of thyroid cancer largely small size papillary thyroid carcinoma (PTC). Prognostic scoring systems have been developed, but these do not take into account the rapidly changing case mix, and adjustments may be required. The purposes of this study were to evaluate treatment outcomes and to analyze the value of older prognostic scoring systems tested on a relatively new, unselected national cohort of PTC patients. METHODS This was a national prospective cohort study conducted in Denmark, which has a population of 5.5 million. RESULTS A total of 1350 patients were diagnosed with PTC during 1996-2008, and the median follow-up time was 7.9 years. The 10-year recurrence-free survival rate was 90.2%, and the 10-year crude and cause-specific survival (CSS) rates were 83.7% and 93.8% respectively. By multivariate Cox regression, it was possible to confirm age, metastases (distant and nodal), extrathyroidal extension, and tumor size as predictors of mortality, whereas only nodal metastases, extrathyroidal extension, and tumor size were predictors of recurrence. In analyses of older prognostic scoring systems, a significant correlation between the risk group ranks was found for survival as well as recurrence. The c-index for CSS was highest for MACIS (0.92) and lowest for AMES (0.80). In the TNM, MACIS, and EORTC systems, most patients were classified as stage 1, and for these patients, the 10-year CSS rate was approximately 99.5%, confirming the generally excellent survival. CONCLUSION This national study provides further evidence that a favorable prognosis is to be expected for patients diagnosed with PTC. Also, it was possible to confirm age, metastases, extrathyroidal extension, and tumor size as predictors of mortality, whereas only nodal metastases, extrathyroidal extension, and tumor size were predictors of recurrence. All the scoring systems evaluated were able to produce a highly significant risk group stratification, showing that in spite of the changes in the case mix of PTC, these systems are still applicable, and in fact contain valuable prognostic information useable for treatment planning.

Completeness and validity in a national clinical thyroid cancer database: DATHYRCA

BACKGROUND Although a prospective national clinical thyroid cancer database (DATHYRCA) has been active in Denmark since January 1, 1996, no assessment of data quality has been performed. The purpose of the study was to evaluate completeness and data validity in the Danish national clinical thyroid cancer database: DATHYRCA. STUDY DESIGN AND SETTING National prospective cohort. Denmark; population 5.5 million. Completeness of case ascertainment was estimated by the independent case ascertainment method using three governmental registries as a reference. The reabstracted record method was used to appraise the validity. For validity assessment 100 cases were randomly selected from the DATHYRCA database; medical records were used as a reference. RESULT The database held 1934 cases of thyroid carcinoma and completeness of case ascertainment was estimated to 90.9%. Completeness of registration was around or above 90% in most instances. Perfect agreement on the diagnosis of thyroid carcinoma was found, both inter- and intra-observer, and κ values of selected variables showed overall good to excellent agreement. CONCLUSION In a setup with public health insurance, personal identity numbers and extended governmental databases, it is possible to establish national clinical cancer databases with a satisfactory completeness and validity. The DATHYRCA database is considered reliable in terms of describing thyroid carcinoma at a national level.

Incidence and prevalence of multiple endocrine neoplasia 2B in Denmark: a nationwide study

Multiple endocrine neoplasia 2B (MEN2B) is an autosomal dominant inherited cancer syndrome associating medullary thyroid carcinoma (MTC), pheochromocytoma (PHEO), ganglioneuromatosis of the aerodigestive tract and facial, ophthalmologic and skeletal abnormalities. MEN2B is caused by the M918T and A883F mutation of the REarranged during Transfection (RET) proto-oncogene in approximately 95% and <5% of cases, respectively. Only very few other mutations have been reported to cause MEN2B. In approximately 75% of MEN2B patients, mutations occur as de novo (Wells et al. 2015). The epidemiology of MEN2B is poorly defined. A nationwide study from Northern Ireland reported of three MEN2B patients and 1,824,000 inhabitants alive at April 21, 2012, yielding a point prevalence of 1.65 per million (Znaczko et al. 2014). However, it is unclear if this is representative of larger populations. A German study reported an MEN2B incidence (M918T carriers only) of 1.4 per million live births per year from 1991 to 2000 and estimated that at least half of all German RET carriers were captured (Machens et al. 2013). Meanwhile, the incidence of MEN2B and M918T carriers in a complete population is undisclosed. We conducted a nationwide study of the incidence and prevalence of MEN2B in Denmark from 1941 to 2014. This retrospective cohort study included 12 unique MEN2B patients identified through the following sources:

The flame retardant DE-71 (a mixture of polybrominated diphenyl ethers) inhibits human differentiated thyroid cell function in vitro

Background Normal thyroid function is essential for general growth and metabolism, but can be affected by endocrine disrupting chemicals (EDCs). Polybrominated diphenyl ethers (PBDEs) have been used worldwide to reduce flammability in different materials and are suspected to be EDCs. The production of the commercial Penta- and OctaBDE mixtures is banned, but DecaBDEs and existing products may leak PBDEs into the environment. Our aim was to investigate the effect of the PentaBDE mixture DE-71 on human thyroid cells in vitro. Materials and methods Primary human thyroid cells were obtained as paraadenomatous tissue and cultured in monolayers. The influence of DE-71 on cyclic adenosine monophosphate (cAMP) and thyroglobulin (Tg) production was examined in the culture medium by competitive radioimmunoassay and enzyme-linked immunosorbent assay, respectively. Real-time quantitative PCR analysis of thyroid-specific genes was performed on the exposed cell cultures. PBDE concentrations were determined in cellular and supernatant fractions of the cultures. Results DE-71 inhibited Tg-release from TSH-stimulated thyrocytes. At 50 mg/L DE-71, mean Tg production was reduced by 71.9% (range: 8.5–98.7%), and cAMP by 95.1% (range: 91.5–98.8%) compared to controls). Expression of mRNA encoding Tg, TPO and TSHr were significantly inhibited (p<0.0001, p = 0.0079, and p = 0.0002, respectively). The majority of DE-71 added was found in the cell fraction. No cytotoxicity was found. Conclusions DE-71 inhibited differentiated thyroid cell functions in a two phase response manner and a concentration-dependent inhibition of Tg and cAMP production, respectively, as well as expression of mRNA encoding Tg, TPO and TSHr. Our findings suggest an inhibiting effect of PBDEs on thyroid cells.

Incidence and prevalence of multiple endocrine neoplasia 2A in Denmark 1901–2014: a nationwide study

Background The incidence and prevalence of multiple endocrine neoplasia 2A (MEN2A) have only been reported once in a nationwide setting. However, it is unclear whether the figures are representative of other populations, as the major component of the syndrome, hereditary medullary thyroid carcinoma (MTC), has been reported as rare in the same country. We conducted a nationwide retrospective cohort study of MEN2A in Denmark from 1901 to 2014, aiming to describe the incidence and prevalence. Methods This study included 250 unique MEN2A patients born or resident in Denmark before December 31, 2014. Patients were identified through the Danish REarranged during Transfection (RET) cohort, linkage of MEN2A pedigrees, the Danish MTC cohort, a nationwide collaboration of MEN2 centers, cross-checking of other relevant cohorts, and a systematic literature search. Results The incidence from 1971 to 2000 was 28 (95% CI: 21–37) per million live births per year. Incidence for the specific mutations or for the overall MEN2A group did not change significantly from 1901 to 2014 (P>0.05). Point prevalence at January 1, 2015, was 24 per million (95% CI: 20–28). Conclusion The incidence and prevalence of MEN2A in Denmark seem higher than those reported in other countries. This is likely explained by the Danish C611Y founder effect. Also, our data indicate no significant change in MEN2A incidence during the last century.

Trends in thyroid cancer: Retrospective analysis of incidence and survival in Denmark 1980–2014

BACKGROUND Thyroid cancer incidence has been reported to be increasing since the 1970 s. The aim of this study was to investigate the change in incidence and survival from 1980 to 2014 in Denmark. METHODS We identified patients registered with thyroid cancer in the period 1980-2014. We evaluated the age-adjusted incidence rate (AAIR) and the average annual percentage change (AAPC), constructed age-period-cohort models (APCs), and evaluated relative survival (RS). RESULTS We included 5139 patients. The AAIR was 1.6 cases per 100,000 in 1980 and 4.5 cases in 2014 with an AAPC of 3.4%. The AAIR for papillary carcinomas (n = 2864) quintupled in the study period, and accounts for most of the observed increase in incidence with an AAPC of 4.9%. Follicular carcinomas (n = 920) nearly tripled in AAIR and had the second greatest increase in AAPC. Papillary carcinomas had the best prognosis with 1-year and 5-year RSs of 95% and 91%, followed by the follicular carcinomas with 1-year and 5-year RSs of 90% and 80%, respectively. Anaplastic carcinomas (n = 320) had the worst prognosis with 1-year and 5-year RSs of 18% and 12%. We found a significant age effect in the APC model for the incidence of thyroid cancer but no significant cohort or period effects. CONCLUSION The incidence of thyroid cancer is rising. This is primarily attributable to an increase in papillary carcinomas. The relative survival has improved significantly in Denmark since 1980. The cause of the increasing incidence remains to be established, but enhanced diagnostic scrutiny and increased iodine intake may be influential.