Investigation of factors potentially influencing calcitonin levels in the screening and follow-up for medullary thyroid carcinoma: a cautionary note

Determinants of circulating calcitonin value: analysis of thyroid features, demographic data, anthropometric characteristics, comorbidities, medications, and smoking habits in a population with histological full exclusion of medullary thyroid carcinoma

Objective

Calcitonin (Ctn) measurement is crucial for the early diagnosis of medullary thyroid carcinoma (MTC). However, Ctn levels can be skewed/elevated due to other reasons, and the Ctn upper reference value remains controversial. In this field, studies have heterogeneous settings, published data are controversial, and no evidence has been achieved. The study's aim was to evaluate all previously investigated Ctn determinants in a population with histological exclusion of MTC.

Methods

The institutional records from 2010 to 2022 were reviewed to select patients with thyroid nodules who had undergone total thyroidectomy with histological exclusion of MTC and who had tested for Ctn just before surgery. Thyroid features, demographic and anthropometric data, comorbidities, medications, and lifestyle information were collected. Univariate and multivariate analyses were performed.

Results

A total of 127 cases were included. The median age for thyroidectomy was 51 years. Median Ctn was 1.04 pg/mL (interquartile range (IQR) 1.04-2.77), with two cases having values above 10 pg/mL. In univariate analysis, Ctn was correlated with gender (p < 0.001), body weight (p = 0.016), height (p = 0.031), body surface area (p = 0.016), thyroid size (p = 0.03), thyroglobulin (p < 0.001), and chronic kidney disease (p < 0.001). After multivariate analysis, the model with the highest accuracy included gender, chronic kidney disease, and thyroid-stimulating hormone (TSH) with an adjusted R-squared of 0.4.

Conclusions

This study demonstrates, in a population histologically proven as MTC-free, that the Ctn value is mainly influenced by gender, anthropometric/thyroid features, and chronic kidney disease, with the further impact of TSH.

Update on Calcitonin Screening for Medullary Thyroid Carcinoma and the Results of a Retrospective Analysis of 12,984 Patients with Thyroid Nodules

BACKGROUND

We provide an update on calcitonin (Ctn) screening for the early detection of medullary thyroid carcinoma (MTC) and present the results of a large single-center analysis evaluating sex-specific cut-off-levels and long-term courses.

METHODS

A total of 12,984 consecutive adult patients (20.1% male and 79.9% female) with thyroid nodules who had undergone routine Ctn measurement were retrospectively analyzed. Patients with confirmed suspicious Ctn values were referred for surgery.

RESULTS

Ctn measurements were elevated in 207 (1.6%) patients, with values below twice the sex-specific reference limit in 82% of these cases. Further clarification was possible in 124/207 cases, of which MTC could be ruled out in 108 cases. Histopathological assessment confirmed MTC in 16/12,984 patients.

CONCLUSIONS

Our extrapolated MTC prevalence of 0.14% is significantly lower than that described in early international screening studies. The stimulation test can usually be dispensable when using a decision-making concept based on sex-specific basal Ctn cut-off values. Ctn screening is recommended even in patients with very small thyroid nodules. High quality standards in pre-analytics, laboratory measurements, and the interpretation of data must be ensured, as well as close interdisciplinary cooperation between medical disciplines.

Preoperative Serum Calcitonin Level and Ultrasonographic Characteristics Predict the Risk of Metastatic Medullary Thyroid Carcinoma: Functional Analysis of Calcitonin-Related Genes

Background. Early cervical lymph node (LN) metastasis is an important cause of poor survival in patients with medullary thyroid cancer (MTC). This study evaluated whether the preoperative serum calcitonin level in combination with ultrasonographic features of MTC can be used to assess the LN status as well as predict the risk of metastasis in patients with MTC. Methods. We retrospectively analyzed the clinical data of 95 patients with MTC, and a nomogram model was constructed and validated. Using integrated database analysis of The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx), we mined pathways wherein CALCA is involved, identified calcitonin-related genes, and analyzed their functions. Results. Correlation analysis revealed a significant association between the infiltrating range, diameter, calcification, blood flow, the preoperative serum calcitonin level, and metastasis. The metastasis risk-prediction model showed great accuracy in determining the risk of metastasis in MTC (area under the curve of the receiver operating characteristic [ROC] curve: 0.979 [95% confidence interval 0.946–1.000]). Decision curve analysis (DCA) showed that the model has excellent clinical utilization potential. Significantly, CALCA, the mRNA for calcitonin, was highly expressed in thyroid cancer tissues and associated with the cytokine–cytokine receptor and neuroactive ligand-receptor interaction pathways as well as the cell-adhesion molecules. ROC curve indicated that the CNTFR, CD27, GDF6, and TSLP genes, which are related to the cytokine–cytokine receptor interaction pathway, could indicate the risk of metastasis in MTC. Conclusions. The preoperative serum calcitonin level, in combination with ultrasonographic features, can be used to predict the risk of metastasis in patients with MTC and constitute a noninvasive accurate method for preoperative diagnosis of MTC.

Presence or severity of Hashimoto's thyroiditis does not influence basal calcitonin levels: observations from CROHT biobank

PURPOSE

The influence of Hashimoto's thyroiditis (HT) on calcitonin (Ct) production is unresolved question. The aim of this study was to explore if basal Ct levels are influenced by the presence/severity of HT or correlated with clinical phenotypes of HT patients.

METHODS

We included 467 HT patients and 184 control participants, from Croatian Biobank of HT patients (CROHT), in this retrospective study. Calcitonin levels between HT patients and controls were compared using Mann-Whitney test. Ct levels between two subgroups of HT patients, divided by intake of levothyroxine (LT4) therapy, were additionally tested to take into account the illness severity. Spearman rank correlation test was used to analyze correlations between Ct levels and 14 relevant phenotypes.

RESULTS

We have not detected significant differences in median Ct levels between HT patients and controls (2.2 vs 2.35 pg/mL, respectively, P = 0.717) nor in-between two subgroups of HT patients (P = 0.347). We have not detected statistically significant correlations between Ct levels and clinical phenotypes, although we identified three weak nominal correlations: negative correlation of Ct with TgAb in all HT patients (r = - 0.1, P = 0.04); negative correlation of Ct with age in subgroup of HT patients without LT4 therapy (r = - 0.13, P = 0.04); positive correlation of Ct with BSA in subgroup of HT patients on LT4 therapy (r = 0.16, P = 0.042).

CONCLUSION

Our results suggest that HT patients of all disease stages preserve Ct production as healthy individuals and there is no need for Ct measurements in the absence of a nodule. Additional confirmation and clarification of observed nominal correlations are needed due to potential clinical relevance of TgAb and age-dependent Ct decrease in HT women.

Calcitonin and complementary biomarkers in the diagnosis of hereditary medullary thyroid carcinoma in children and adolescents

OBJECTIVES

Medullary thyroid carcinoma (MTC) is a rare malignancy that is effectively curable by surgery. Unlike in adults, hereditary MTC has a predominant role in children. A fast and safe diagnosis is important to assure the good prognosis for the patients. A major cornerstone is the assessment of biomarkers, but the interpretation must respect their pre-, post- and analytical features. Especially calcitonin (Ctn) is a challenging biomarker in daily laboratory diagnostics. However, Ctn is of particular relevance for the diagnostic in MTC. The American Thyroid Association recommends thyroidectomy if the upper reference range of Ctn is exceeded. Interestingly, age-dependent reference ranges for children and adolescents have become available only recently for Ctn assays. With this review, we aim to highlight the importance of a timely diagnosis of MTC in children and adolescents.

CONTENT

Recent developments in pediatric biochemical diagnostics of MTC were summarized. This includes guidance on interpretation of RET, Ctn, procalcitonin, carcinoembryonic antigen, carbohydrate antigen 19-9, and chromogranin A.

SUMMARY

Currently, Ctn is the most investigated biomarker in the diagnosis of MTC in children and adolescents. Other biomarkers as PCT suggest complementary evidence about pediatric MTC but their interpretation based largely on adult's data. A successful treatment of MTC requires, besides results of biomarkers, information about medical history, RET gene analysis and recent guideline knowledge.

OUTLOOK

More research is required to validate complementary biomarkers of Ctn in children. Additionally, the effect of different confounder on pediatric Ctn levels has to be further clarified.

Diagnostic Challenges of Medullary Thyroid Carcinoma

BACKGROUND

Medullary thyroid carcinoma (MTC) comprises 1-2% of all thyroid cancers, yet 15% of all thyroid cancer-related deaths. While up to 20% of cases may be predicted due to autosomal dominant germline mutations, 80% of cases are sporadic. However, due to non-specific presenting symptoms and diagnostic imaging, prompt diagnosis and treatment has remained elusive. This article will further investigate the limitations of MTC diagnosis and look into future areas for diagnostic improvement.

METHODS

Relevant articles were identified using a systematic PubMed and Google Scholar search.

RESULTS

Prophylactic total thyroidectomy for the 20% of MTC cases that are present in autosomal dominant disorder provides definitive treatment. Serum calcitonin (Ctn) screening has several technical limitations due to population variability and laboratory assay interference, but advances in laboratory technology and combined use with fine needle aspiration increase its sensitivity. Other serum assays such as carcinoembryonic antigen and procalcitonin have limited applicability. Thyroid ultrasound remains the gold standard for the initial diagnostic planning, with limited application for CT, MRI, and PET imaging.

CONCLUSION

With complete surgical resection the only definitive treatment, early MTC diagnosis has presented an elusive challenge, mainly due to its relative rarity and difficulty in finding an economic screening strategy. Careful family history combined with fine needle aspiration with serum Ctn analysis can improve diagnostic sensitivity and specificity to greater than 95%.

INCREASED SERUM CALCITONIN IN SPORADIC PRIMARY HYPERPARATHYROIDISM IS AN UNCOMMON OCCURRENCE

Objective: To evaluate calcitonin (CT) levels in sporadic primary hyperparathyroidism (PHPT), which has to date rarely been considered. Methods: We evaluated serum CT levels in 290 consecutive patients with sporadic PHPT at diagnosis. Results: Mild elevations in CT levels (hyperCT) were found in 25 patients (8.6%), with no correlation among the demographic, clinical, and biochemical findings. In addition, no differences were found between patients with and without hyperCT. Follow-up data were available for 19/25 patients, but CT values were only available for 10. CT normalized in all surgically cured patients regardless of the extent of the surgery (parathyroidectomy [PTX] only in 8 and associated with partial or total thyroidectomy for benign nodular goiters in 7). Conclusion: hyperCT is an uncommon feature of sporadic PHPT and not related to biochemical or clinical features of the disease. In addition, hyperCT is reversible after PTX, regardless of whether concomitant thyroidectomies have been conducted. Abbreviations: CT = calcitonin; eGFR = estimated glomerular filtration rate; hyperCT = hypercalcitoninemia; MEN = multiple endocrine neoplasm; MTC = medullary thyroid carcinoma; PHPT = primary hyperparathyroidism; PPI = proton pump inhibitor; PTH = parathyroid hormone; PTX = parathyroidectomy.

A cut-off value of basal serum calcitonin for detecting macroscopic medullary thyroid carcinoma

OBJECTIVE

Serum calcitonin (CT) level is used to detect medullary thyroid carcinoma (MTC), but the cut-off level is unclear. We aimed at identifying the optimal cut-off value of basal serum CT levels for detecting MTC.

DESIGN AND PATIENTS

We retrospectively enrolled patients with hypercalcitoninemia (≥2·9 pmol/l) who had undergone thyroid ultrasonography (US) and subsequent work-up between 2001 and 2013 at Asan Medical Center. We divided patients into four groups: proven MTC (group 1, n = 93), pathologically proven non-MTC after surgery (group 2, n = 57), benign single nodule by cytology (group 3, n = 68) and patients without nodules on US (group 4, n = 24).

MEASUREMENT

Basal serum CT levels were evaluated.

RESULTS

The median CT level of group 1 (119·5 pmol/l) was significantly higher than those of other groups (4·0, 3·8 and 3·8 pmol/l, P < 0·001). When we adopted 19·0 pmol/l of CT level as a cut-off value, the sensitivity, specificity, and positive and negative predictive values were 77·4%, 98·7%, 97·3% and 87·8%, respectively. When we compared 29·2 pmol/l (100 pg/ml) and 19·0 pmol/l (65 pg/ml) as cut-off values, 19·0 pmol/l was more sensitive and accurate than 29·2 pmol/l. Factors associated with hypercalcitoninemia in non-MTC groups were autoimmune thyroiditis, chronic kidney disease, proton pump inhibitors and other malignancies. Serum CT levels tended to decrease spontaneously in non-MTC groups.

CONCLUSION

Basal serum CT levels higher than 19·0 pmol/l can be a useful cut-off value for detecting macroscopic MTC, even though values below 19·0 pmol/l cannot exclude the presence of MTC like small volume MTC or premalignant C-cell hyperplasia.

Calcitonin as Biomarker for the Medullary Thyroid Carcinoma

Calcitonin (CTN) is a polypeptide hormone consisting of 32 amino acids with a disulfide bridge between position 1 and 7 that is mainly produced by the C-cells of thyroid gland. The measurement of CTN concentrations in blood reflects C-cell activity and is performed in general by immunoassay methods. However, there are analytical, physiological, pharmacological, and pathological factors that can influence results of serum CTN values. Due to the influence of these factors, there is a high variability in assay-dependent cutoffs used to discriminate between MTC, C-cell hyperplasia (CCH), and the absence of the pathological impairment of C-cells. There is a lot of evidence that the measurement of serum CTN concentrations in patients with thyroid nodules can lead to an earlier diagnosis of MTC or CCH than the exclusive use of imaging procedures and/or fine-needle aspiration cytology. Basal CTN concentrations higher than 60-100 pg/mL are highly indicative for the diagnosis MTC. In the range between cutoff and 60 pg/mL CTN, both MTC and HCC may be a relevant diagnosis. PCT and CTN appear to have a comparable diagnostic capability to diagnose MTCs. However, "positive" PCT values of more than 50 pg/mL may be reached also in subclinical infections and will lead, therefore, to an overdiagnosis of the tumor. Pentagastrin- or calcium-stimulated serum CTN concentrations higher than cutoff values might improve diagnostics of MTC, but the non-availability of the first and the lacking of relevant cutoff values for the second tool favors the use of only basal values currently.