Factors affecting lymph node yield and density in neck dissection.

BACKGROUND: Studies suggest that neck dissections with a minimum of 16-18 yielded nodes are associated with better overall survival compared to neck dissections with lower yields. AIMS: We aimed to identify factors affecting the lymph node yield and density in patients with oral cavity cancer undergoing elective neck dissection levels 1-3. MATERIALS AND METHODS: Using prospectively registered data, we conducted a population-based cohort study on all patients surgically treated for oral cavity cancer including levels 1-3 neck dissection at our institution from 2018 to 2022. Uni and multivariate analyses were performed to identify factors associated with lymph node yields. RESULTS: In total, 221 patients were included. The mean lymph nodes yield and density were 19 (95%CI 18-20) and 0.12 (95%CI 0.09-0.16), respectively. In multivariate analysis, increasing body weight (p = .034) was positively and previous radiotherapy (p = .006) were negatively correlated with the number of yielded lymph nodes. Lymph node density was positively correlated with body weight (p = .011) and body mass index (p = .032) in univariate analysis. CONCLUSIONS AND SIGNIFICANCE: Increasing body weight was positively and previous radiotherapy was negatively correlated to lymph node yield. These factors should be taken into consideration when interpreting the lymph node yield as an indicator of neck dissection quality.

Predictors in the treatment of malignant central airway obstruction with silicone stents.

PURPOSE: To examine the role of the silicone stent in palliation of malignant central airway obstruction and identify potential preprocedural predictors for postprocedural outcome. METHODS: Patients treated with endoscopic insertion of tracheobronchial silicone stents for malignant central airway obstruction at Aarhus University Hospital from 2012 to 2022 were identified from electronic medical records. Statistical analyses were carried out to identify factors affecting Days Alive and Out of Hospital, complications and overall survival. RESULTS: 81 patients underwent a total of 90 tracheobronchial stent insertions. Days Alive and Out of Hospital (DAOH) for the first 30 days were affected negatively by urgent intervention, p < 0.001, preprocedural non-invasive respiratory support, p < 0.001, and preprocedural intubation, p = 0.02. Post-procedural oncological treatment was associated with a significant improved DAOH, p = 0.04. Symptomatology and lesion characteristics were not significantly associated with any impact on DAOH. Overall survival was poor (mean survival was 158 days), and only significantly affected by severe degree of dyspnea, p = 0.02, and postprocedural oncological treatment, p < 0.001. Complication where registered in 25.6% of cases within the first 30 days was observed. Procedure-related mortality was 3.7%. Based on chart annotations by an ENT-surgeon, 95% of the patients experienced relief of symptoms following stent insertion. CONCLUSIONS: Palliative tracheobronchial airway stenting with silicone stents is found to have a beneficial impact, more research is required for identification of predictors for postprocedural outcome based on preprocedural classifications.

Laryngo-tracheal resections in the Nordic countries: an option for further centralization?

PURPOSE: We aimed to obtain information on the number of Nordic centers performing tracheal resections, crico-tracheal resections, and laryngo-tracheal reconstructions, as well as the patient volume and the standard regimens associated with these procedures. METHODS: Consultants at all Departments of Otorhinolaryngology-Head and Neck Surgery (ORL-HNS, n = 22) and Thoracic Surgery (n = 21) in the five Nordic countries were invited (April 2018-January 2019) to participate in an online survey. RESULTS: All 43 departments responded to the survey. Twenty departments declared to perform one or more of the three types of tracheal resections. At five hospitals, departments of ORL-HNS and Thoracic Surgery perform these operations in collaboration. Hence, one or more of the tracheal operations in question are carried out at 15 centers. The median annual number of tracheal operations per center is five (range 1-20). Great variations were found regarding contraindications (relative and absolute) for surgery, the use of guardian sterno-mental sutures (all patients, 33%; selected cases, 40% of centers), prophylactic antibiotic therapy (cefuroxime +/- metronidazole, penicillin +/- metronidazole, clindamycin, imipenem, or none), post-operative follow-up time (range: children: 3-120 months; adults: 0-60 months), and the performance of post-operative bronchoscopy. CONCLUSIONS: Fifteen centers each perform a low number of annual operations with significant variations in the selection of patients and the clinical setup, which raises the question if a higher degree of collaboration and centralization would be warranted. We encourage Nordic transnational collaboration, pursuing alignment on central management issues, and establishment of a common prospective database for future tracheal resection surgery.

Incidental and Non-incidental Papillary Thyroid Microcarcinoma in Denmark 1996-2015: A national study on incidence, outcome and thoughts on active surveillance.

BACKGROUND: Incidental and non-incidental papillary microcarcinomas (PMC) are associated with different outcomes and treatment options may vary. The least favourable outcome is typically seen when carcinoma is suspected prior to surgery. Only a few studies have addressed the prognosis based on the way of detection for PMC, and they have been limited to retrospective single-center studies. We hypothesize that the "way of detection" may predict prognosis. The aim was to calculate the incidence and outcome of PMC based on the way of detection and to identify patients that may be suitable for active surveillance. METHOD: This national cohort study consists of 803 patients diagnosed with PMC in Denmark from 1996 to 2015. Patients were identified from the DATHYRCA database and allocated into groups according to the way of detection leading to surgery: Incidental at surgery (n = 527), non-incidental with symptoms suspected from the index tumor (n = 134) and non-incidental with symptoms suspected from a metastasis (n = 142). RESULTS: Age-standardized incidence rates increased from 0.35 per 100,000 per year in 1996 to 1.19 per 100,000 per year in 2015. A significant rise in incidence was found for both the incidental group and non-incidental group with symptoms suspected from a metastasis. Recurrence free survival was significantly worse for patients with suspicion of metastasis prior to surgery than patient groups without. No difference in mortality was found between groups. CONCLUSION: PMC patients without suspicion of metastasis have the same low risk of recurrence as incidental cases and may be candidates for active surveillance.

Survival and Long-Term Biochemical Cure in Medullary Thyroid Carcinoma in Denmark 1997-2014: A Nationwide Study.

BACKGROUND: Survival of medullary thyroid carcinoma (MTC) subgroups in relation to the general population is poorly described. Data on the factors predicting long-term biochemical cure in MTC patients are nonexistent at a population level. A nationwide retrospective cohort study of MTC in Denmark from 1997 to 2014 was conducted, aiming to detect subgroups with survival similar to that of the general population and to identify prognostic factors for disease-specific survival and long-term biochemical cure. METHODS: The study included 220 patients identified from the nationwide Danish MTC cohort between 1997 and 2014. As a representative sample of the general population, a reference population matched 50:1 to the MTC cohort was used. RESULTS: Patients diagnosed with hereditary MTC by screening (hazard ratio [HR] = 1.5 [confidence interval (CI) 0.5-4.3]), patients without regional metastases (HR = 1.4 [CI 0.9-2.3]), and patients with stage I (HR = 1.3 [CI 0.6-3.1]), stage II (HR = 1.1 [CI 0.6-2.3]), and III (HR = 1.3 [CI 0.4-4.2]) disease had an overall survival similar to the reference population. On multivariate analysis, the presence of distant metastases (HR = 12.3 [CI 6.0-25.0]) predicted worse disease-specific survival, while the absence of regional lymph node metastases (odds ratio = 40.1 [CI 12.0-133.7]) was the only independent prognostic factor for long-term biochemical cure. CONCLUSIONS: Patients with hereditary MTC diagnosed by screening, patients without regional metastases, and patients with stages I, II, and III disease may have similar survival as the general population. The presence of distant metastases predicted worse disease-specific survival, while the absence of regional metastases predicted long-term biochemical cure.

Completeness of RET testing in patients with medullary thyroid carcinoma in Denmark 1997-2013: a nationwide study.

BACKGROUND: The completeness of REarranged during Transfection (RET) testing in patients with medullary thyroid carcinoma (MTC) was recently reported as 60%. However, the completeness on a population level is unknown. Similarly, it is unknown if the first Danish guidelines from 2002, recommending RET testing in all MTC patients, improved completeness in Denmark. We conducted a nationwide retrospective cohort study aiming to evaluate the completeness of RET testing in the Danish MTC cohort. Additionally, we aimed to assess the completeness before and after publication of the first Danish guidelines and characterize MTC patients who had not been tested. METHODS: The study included 200 patients identified from the nationwide Danish MTC cohort 1997-2013. To identify RET tested MTC patients before December 31, 2014, the MTC cohort was cross-checked with the nationwide Danish RET cohort 1994-2014. To characterize MTC patients who had not been RET tested, we reviewed their medical records and compared them with MTC patients who had been tested. RESULTS: Completeness of RET testing in the overall MTC cohort was 87% (95% CI: 0.81-0.91; 173/200). In the adjusted MTC cohort, after excluding patients diagnosed with hereditary MTC by screening, completeness was 83% (95% CI: 0.76-0.88; 131/158). Completeness was 88% (95% CI: 0.75-0.95; 42/48) and 81% (95% CI: 0.72-0.88) (89/110) before and after publication of the first Danish guidelines, respectively. Patients not RET tested had a higher median age at diagnosis compared to those RET tested. Median time to death was shorter in those not tested relative to those tested. CONCLUSION: The completeness of RET testing in MTC patients in Denmark seems to be higher than reported in other cohorts. No improvement in completeness was detected after publication of the first Danish guidelines. In addition, data indicate that advanced age and low life expectancy at MTC diagnosis may serve as prognostic indicators to identify patients having a higher likelihood of missing the compulsory RET test.

Single-stage tracheal and cricotracheal segmental resection with end-to-end anastomosis: Outcome, complications, and risk factors.

OBJECTIVE: Management of tracheal stenosis remains controversial. Endoscopic interventions commonly provide immediate relief of symptoms, but are associated with high recurrence rates. In contrast, high success rates have been reported in patients undergoing tracheal resection. However, well-defined indications and contraindications for tracheal resection are lacking and previous studies commonly ignore patient-related outcomes (e.g. dyspnoea). We aimed to evaluate the outcome of tracheal resection at our institution and identify risk factors for complications. METHODS: All adult patients undergoing tracheal resection at Aarhus University Hospital between January 2009 and September 2016 were included RESULTS: Twenty-seven patients were included. The most frequent aetiologies for tracheal stenosis were previous tracheostomy (n=8), prolonged intubation (n=3), a combination of the two (n=5), and intraluminal tumour (n=7). Sixteen patients underwent high tracheal resection, seven patients low tracheal resection, and four patients partial cricotracheal resection. Surgical success (no dyspnoea and no need for additional intervention) was achieved in 74% of patients. Four of six patients undergoing resection because of malignant disease were recurrence-free during the follow-up period. Fifteen (56%) patients suffered complications (transient or permanent). Four (15%) patients had recurrent stenosis and underwent reintervention. Other permanent complications included idiopathic hoarseness (15%), unilateral recurrent nerve palsy (11%), and dysphagia (7%). Previous treatment (endoscopic and open surgery) (OR=5.5, p=0.06) and chronic diseases (OR=8.3, p=0.02) were associated with increased risk for complications. CONCLUSIONS: Tracheal resection was efficient treatment for the alleviation of dyspnoea in adults with tracheal stenosis. However, complications were frequent and careful preoperative patient selection and information are crucial.

Replication of newly proposed TNM staging system for medullary thyroid carcinoma: a nationwide study.

A recent study proposed new TNM groupings for better survival discrimination among stage groups for medullary thyroid carcinoma (MTC) and validated these groupings in a population-based cohort in the United States. However, it is unknown how well the groupings perform in populations outside the United States. Consequently, we conducted the first population-based study aiming to evaluate if the recently proposed TNM groupings provide better survival discrimination than the current American Joint Committee on Cancer (AJCC) TNM staging system (seventh and eighth edition) in a nationwide MTC cohort outside the United States. This retrospective cohort study included 191 patients identified from the nationwide Danish MTC cohort between 1997 and 2014. In multivariate analysis, hazard ratios for overall survival under the current AJCC TNM staging system vs the proposed TNM groupings with stage I as reference were 1.32 (95% CI: 0.38-4.57) vs 3.04 (95% CI: 1.38-6.67) for stage II, 2.06 (95% CI: 0.45-9.39) vs 3.59 (95% CI: 1.61-8.03) for stage III and 5.87 (95% CI: 2.02-17.01) vs 59.26 (20.53-171.02) for stage IV. The newly proposed TNM groupings appear to provide better survival discrimination in the nationwide Danish MTC cohort than the current AJCC TNM staging. Adaption of the proposed TNM groupings by the current AJCC TNM staging system may potentially improve accurateness in survival discrimination. However, before such an adaption further population-based studies securing external validity are needed.

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.

Is serum TSH a biomarker of thyroid carcinoma in patients residing in a mildly iodine-deficient area?

PURPOSE: To investigate the association between the pre-operative serum TSH (s-TSH) level and differentiated thyroid carcinoma (DTC) in a mildly iodine-deficient area. METHODS: Patients undergoing surgery for thyroid nodular disease (TND) were included from three tertiary surgical departments. Data were collected from a national thyroid surgery database (THYKIR) and from patient charts. Individuals with overtly coexisting thyroid disorders were excluded for subgroup analyses. Patients were compared with the Danish background population, employing previous data from DanThyr, a study initiated to monitor the iodine fortification program in Denmark. RESULTS: Nine-hundred ninety-eight patients [cases/controls: 265/733; female/male: 794/204; age (mean ± SD): 51 ± 15 years] were included. S-TSH was significantly higher in the DTC group [median (IQR): 1.3 (0.9-1.9 mIU/L)] compared with the benign TND group [0.9 (0.6-1.5 mIU/L)] (p < 0.0001). The median s-TSH in the background population was similar to that found among DTC patients (p = 1.00), but markedly higher than the s-TSH level in the benign TND group (p < 0.0001). There was no association between s-TSH and DTC disease stage (p = 0.08-0.87). CONCLUSIONS: s-TSH was significantly higher in patients with DTC than in those with benign TND. However, this difference can be explained by abnormally lower s-TSH level in the latter group, probably caused by subtle nodular functional autonomy. Due to the huge overlap and the small difference in median s-TSH between patients with benign and malignant TND, s-TSH is not suitable as a biomarker of DTC in a clinical setting.

Incidence and prevalence of sporadic and hereditary MTC in Denmark 1960-2014: a nationwide study.

Recent studies have shown a significant increase in the temporal trend of medullary thyroid carcinoma (MTC) incidence. However, it remains unknown to which extent sporadic medullary thyroid carcinoma (SMTC) and hereditary MTC (HMTC) affect the MTC incidence over time. We conducted a nationwide retrospective study using previously described RET and MTC cohorts combined with review of medical records, pedigree comparison and relevant nationwide registries. The study included 474 MTC patients diagnosed in Denmark between 1960 and 2014. In the nationwide period from 1997 to 2014, we recorded a mean age-standardized incidence of all MTC, SMTC and HMTC of 0.19, 0.13 and 0.06 per 100,000 per year, respectively. The average annual percentage change in incidence for all MTC, SMTC and HMTC were 1.0 (P = 0.542), 2.8 (P = 0.125) and -3.1 (P = 0.324), respectively. The corresponding figures for point prevalence at January 1, 2015 were 3.8, 2.5 and 1.3 per 100,000, respectively. The average annual percentage change in prevalence from 1998 to 2015 for all MTC, SMTC and HMTC was 2.8 (P < 0.001), 3.8 (P < 0.001) and 1.5 (P = 0.010), respectively. We found no significant change in the incidence of all MTC, SMTC and HMTC possibly due to our small sample size. However, due to an increasing trend in the incidence of all MTC and opposing trends of SMTC (increasing) and HMTC (decreasing) incidence, it seems plausible that an increase for all MTC seen by others may be driven by the SMTC group rather than the HMTC group.

Anaplastic thyroid carcinoma in Denmark 1996-2012: A national prospective study of 219 patients.

BACKGROUND: Anaplastic thyroid carcinoma (ATC) is the least common but most malignant thyroid cancer. We aimed to examine the characteristics as well as evaluate the incidence, prognostic factors, and if introduction of a fast track cancer program might influence survival in a cohort of ATC patients. METHODS: A cohort study based on prospective data from the national Danish thyroid cancer database DATHYRCA and the national Danish Pathology Register including 219 patients diagnosed from 1996 to 2012, whom were followed until death or through September 2014. RESULTS: We found the median age in the 7th decade, the majority of patients being women presenting with a growing mass at the neck, diagnosed with stage T4b disease. At diagnosis, 56% of the patients had lymph node metastasis and 38% distant metastasis. We observed one- and five-year survival of 20.7% and 11.0%, respectively. Both univariate and multivariate analyses showed age (above 73.6 years), respiratory impairment, T4b stage, and distant metastasis at diagnosis to be significant prognostic factors. Further, introduction of a national fast track cancer program increased survival nearly two-fold. CONCLUSION: As new information, our study adds "respiratory impairment at diagnosis" and "introduction of a national fast track cancer program" to the list of already established prognostic indicators for ATC.

Deep head and neck infection causing pathological fracture of the mandibular condyle.

We report an unusual case of a 46-year-old male with a severe deep head and neck infection after extraction of two mandibular molars that led to a potentially life-threatening condition and caused pathological fracture of the mandibular condyle. This is the first published spontaneous pathological fracture of the mandibular condyle caused by an infection spread from a lower molar tooth. Based on CT scan we discuss the pathways of infection of odontogenic origin and the reflections of treatment. This case report illustrates an unusual presentation of a spontaneous pathological condylar fracture caused by a severe life-threatening infection after tooth extraction. It details the examination and management of the patient and reflections about the treatment.

Gene-expression Classifier in Papillary Thyroid Carcinoma: Validation and Application of a Classifier for Prognostication.

BACKGROUND: No reliable biomarker for metastatic potential in the risk stratification of papillary thyroid carcinoma exists. We aimed to develop a gene-expression classifier for metastatic potential. MATERIALS AND METHODS: Genome-wide expression analyses were used. Development cohort: freshly frozen tissue from 38 patients was collected between the years 1986 and 2009. Validation cohort: formalin-fixed paraffin-embedded tissues were collected from 183 consecutively treated patients. RESULTS: A 17-gene classifier was identified based on the expression values in patients with and without metastasis in the development cohort. The 17-gene classifier for regional/distant metastasis identified was tested against the clinical status in the validation cohort. Sensitivity for detection of metastases was 51.5% and specificity 61.6%. Log-rank testing failed to identify any significance (p=0.32) regarding the classifier's usefulness as a prognostic marker for recurrence. CONCLUSION: A 17-gene classifier for metastatic potential was developed, and the results showed a clear biological difference between groups. However, through validation, no prognostic significance of this classifier was shown.

Does age affect prognosis in salivary gland carcinoma patients? A national Danish study.

AIM: To compare incidence, histology, treatment modalities, disease stages, and outcome in elderly patients (≥70 years) compared to younger (<70 years). METHODS: From the national Danish salivary gland carcinoma database, 871 patients diagnosed with a primary salivary gland carcinoma from January 1990 to December 2005 were identified. Variables necessary for statistical analyses were extracted from the database. RESULTS: The younger patients have a significantly better crude, disease-specific and recurrence-free survival than the elderly ones. In univariate analysis, significantly more patients in the young group were WHO performance status 0 and in disease stage I + II, and they presented with significantly more histological low grade tumors. In multivariate analysis, chronological age seemed to be of no prognostic significance to salivary gland carcinoma patients as opposed to performance status, disease stage and histological grade. CONCLUSIONS: Salivary gland carcinoma patients over the age of 70 years have a poor prognosis compared to younger patients, which can be explained by higher disease stages, more histological high grade subtypes and a poorer performance status at the time of diagnosis.

Salivary adenoid cystic carcinoma in Denmark 1990-2005: Outcome and independent prognostic factors including the benefit of radiotherapy. Results of the Danish Head and Neck Cancer Group (DAHANCA).

AIM: To describe outcome and prognostic factors, including the effect of radiotherapy, in a consecutive national series of salivary gland adenoid cystic carcinomas. METHODS: From the national Danish salivary gland carcinoma database in the structure of DAHANCA, 201 patients diagnosed with adenoid cystic carcinoma, and treated with a curative intent, were identified in the period between 1990 and 2005. Variables necessary for statistical analyses were extracted from the database. RESULTS: The 10-year crude survival and disease specific survival rates were 58% and 75%, respectively. The 10-year locoregional control rate was 70%, and 36% of patients experienced a recurrence during follow-up (median 7.5 years); 18% developed distant metastases (most commonly to the lungs). In multivariate analysis, stage and margin status were both important factors with regards to survival and locoregional control. Radiotherapy did not improve survival, but it did improve the locoregional control rate. CONCLUSIONS: The treatment of choice is surgery with as wide margins as possible including elective, selective neck dissection. Adjuvant radiotherapy should be considered in patients with incomplete tumor resection, high disease stages, and tumors with a solid growth pattern.

Papillary thyroid carcinoma in Denmark, 1996-2008: outcome and evaluation of established prognostic scoring systems in a prospective national cohort.

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.