CA19-9 as a Predictor of Worse Clinical Outcome in Medullary Thyroid Carcinoma

Metagenomic Microbial Signatures for Noninvasive Detection of Pancreatic Cancer

Background/Objectives: Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy with poor early detection rates owing to the limited sensitivity and specificity of the current biomarker CA19-9. Gut microbiota dysbiosis plays a key role in PDAC pathogenesis. This study aimed to evaluate the noninvasive approach we developed, combining metagenome-derived microbial signatures with CA19-9, to improve PDAC detection. Methods: This study included 50 treatment-naïve patients with PDAC and their matched controls. Fecal samples were analyzed using shotgun metagenomic sequencing. Machine learning algorithms were used to develop and validate a diagnostic panel integrating microbial signatures and CA19-9 levels. Subgroup analyses were used to confirm the robustness of the microbial markers. Results: The combined models at both species and genus levels effectively distinguished patients with PDAC from healthy individuals, and their strong diagnostic efficacy and accuracy were demonstrated through rigorous validation. Conclusions: In conclusion, the combination of gut microbiome profiling and CA19-9 improves PDAC detection accuracy compared to the use of CA19-9 alone, showing promise for early and noninvasive diagnosis.

Circulating Biomarkers of Thyroid Cancer: An Appraisal

Thyroid cancer is the most prevalent endocrine cancer. The prognosis depends on the type and stage at diagnosis. Thyroid cancer treatments involve surgery, possibly followed by additional therapeutic options such as hormone therapy, radiation therapy, targeted therapy and chemotherapy. Besides the well-known thyroid tumor biomarkers, new circulating biomarkers are now emerging. Advances in genomic, transcriptomic and proteomic technologies have allowed the development of novel tumor biomarkers. This review explores the current literature data to critically analyze the benefits and limitations of routinely measured circulating biomarkers for the diagnosis and monitoring of thyroid cancer. The review also sheds light on new circulating biomarkers, focusing on the challenges of their use in the clinical management of thyroid cancer, underlining the need for the identification of a new generation of circulating biomarkers.

Epidemiology, Clinical Presentation, and Diagnosis of Medullary Thyroid Carcinoma

Medullary thyroid carcinoma (MTC) is a rare neuroendocrine tumor originating from thyroid C cells that produces mainly calcitonin (Ctn) and is used as a tumor marker. MTC can occur either sporadically (75%) or in a hereditary variant (multiple endocrine neoplasia type 2, MEN2) due to germline mutations in the RET proto-oncogene. The discovery of MTC in a patient has several diagnostic implications involving a specific strategy, preoperative evaluation of the tumor marker Ctn and the extent of the disease, classification of MTC as sporadic or hereditary using germline RET testing, screening for associated endocrinopathies in hereditary MTC, and somatic RET testing in sporadic MTC. Elevated Ctn is a highly sensitive and specific tumor marker for the diagnosis and follow-up of MTC. Ctn is directly related to the tumor mass. In patients with nodular thyroid disease, MTC can be diagnosed by Ctn determination. Ctn is an indicator of tumor burden. Patients with confirmed sporadic or hereditary MTC should undergo total thyroidectomy. Depending on the preoperative Ctn value, additional dissection of the lymph nodes in the central and lateral neck compartments should be performed. In MEN 2 patients diagnosed by RET mutation analysis, the timing of prophylactic thyroidectomy depends on the specific RET mutation and Ctn level.

The Past, Present, and Future of Biomarkers for the Early Diagnosis of Pancreatic Cancer

Pancreatic cancer is one of the most aggressive cancers with a very poor 5-year survival rate and reduced therapeutic options when diagnosed in an advanced stage. The dismal prognosis of pancreatic cancer has guided significant efforts to discover novel biomarkers in order to anticipate diagnosis, increasing the population of patients who can benefit from curative surgical treatment. CA 19-9 is the reference biomarker that supports the diagnosis and guides the response to treatments. However, it has significant limitations, a low specificity, and is inefficient as a screening tool. Several potential biomarkers have been discovered in the serum, urine, feces, and pancreatic juice of patients. However, most of this evidence needs further validation in larger cohorts. The advent of advanced omics sciences and liquid biopsy techniques has further enhanced this field of research. The aim of this review is to analyze the historical evolution of the research on novel biomarkers for the early diagnosis of pancreatic cancer, focusing on the current evidence for the most promising biomarkers from different body fluids and the novel trends in research, such as omics sciences and liquid biopsy, in order to favor the application of modern personalized medicine.

CA19-9 producing locally advanced papillary thyroid carcinoma: a case report

BACKGROUND

CA19-9 is a tumor marker for gastrointestinal and biliary-pancreatic adenocarcinomas; however, its association with thyroid cancer is unknown. Here, we report a case of CA19-9 producing locally advanced papillary thyroid carcinoma (PTC).

CASE PRESENTATION

A 66-year-old woman who was identified with a thyroid tumor after a close examination of an elevated serum CA19-9 level, which was detected at health screening, was referred to our hospital. Ultrasonography revealed a 34 × 31 mm hypoechoic lesion in the lower pole of the left thyroid lobe. Computed tomography revealed a solid thyroid tumor with tracheal invasion without any distant metastases. Bronchoscopy revealed tumor exposure into the tracheal lumen on the left side of the trachea. Fine-needle aspiration cytology led to a diagnosis of papillary thyroid carcinoma (PTC). The patient underwent a total thyroidectomy, tracheal sleeve resection with end-to-end anastomosis, and lymph node dissection in the left cervical and superior mediastinal regions (D3c) with a reversed T-shaped upper sternotomy down to the third intercostal level. Histopathological analysis confirmed the diagnosis of PTC with tracheal invasion and no lymph node metastases (pT4a Ex2 N0). Immunohistochemical staining showed the expression of CA19-9 in cancer cells. Postoperatively, the serum CA19-9 level of the patient decreased to within the normal range.

CONCLUSIONS

Some PTCs produce CA19-9, although less frequently. When elevated serum CA19-9 levels are observed, PTC should be included in the differential diagnosis for further investigation.

Serum Biochemical Markers for Medullary Thyroid Carcinoma: An Update

INTRODUCTION

Medullary thyroid carcinoma (MTC), a rare malignancy, requires early diagnosis for optimal patient outcomes. An important aspect of MTC diagnosis is the assessment of serum biomarkers. This review aimed to evaluate the use of serum biomarkers in the diagnosis, prognosis, and follow-up of MTC.

METHODS

A thorough search of PubMed covering 1975 to 2022 was conducted to identify English-language articles on MTC serum biomarkers.

RESULTS

The review revealed that calcitonin (Ctn) and carcinoembryonic antigen (CEA) remain the most important serum biomarkers for MTC diagnosis and management. Despite limited studies on procalcitonin (PCT), its stability and ability to exclude interference from inflammation make it a valuable potential marker of MTC. Although the positive rate of serum CA19-9 levels in MTC patients was not high, it can be used as an indicator of poor prognosis in advanced MTC. Other serum markers, including chromogranin A, gastrin-releasing peptide precursor, and neurospecific enolase, did not show any unique value in MTC diagnosis and management.

CONCLUSION

Taken together, this review emphasized the importance of serum biomarkers, particularly Ctn and CEA, in the diagnosis and management of MTC. PCT shows promise as a valuable potential marker, whereas CA19-9 can be used as a prognostic indicator of advanced MTC. Further research is needed to validate the significance of these serum biomarkers in MTC and determine the effects of confounding factors on their levels. Clinicians should consider using these markers in MTC diagnosis, prognosis, and follow-up, particularly for patients with advanced disease.

Dynamics of Serum CA19-9 in Patients Undergoing Pancreatic Cancer Resection

BACKGROUND

Carbohydrate antigen (CA) 19-9 is an established perioperative prognostic biomarker for pancreatic ductal adenocarcinoma (PDAC). However, it is unclear how CA19-9 monitoring should be used during postoperative surveillance to detect recurrence and to guide the initiation of recurrence-focused therapy.

OBJECTIVE

This study aimed to elucidate the value of CA19-9 as a diagnostic biomarker for disease recurrence in patients who underwent PDAC resection.

METHODS

Serum CA19-9 levels at diagnosis, after surgery, and during postoperative follow-up were analyzed in patients who underwent PDAC resection. All patients with at least two postoperative follow-up CA19-9 measurements before recurrence were included. Patients deemed to be nonsecretors of CA19-9 were excluded. The relative increase in postoperative CA19-9 was calculated for each patient by dividing the maximum postoperative CA19-9 value by the first postoperative value. Receiver operating characteristic analysis was performed to identify the optimal threshold for the relative increase in CA19-9 levels to identify recurrence in the training set using Youden's index. The performance of this cutoff was validated in a test set by calculating the area under the curve (AUC) and was compared to the performance of the optimal cutoff for postoperative CA19-9 measurements as a continuous value. In addition, sensitivity, specificity, and predictive values were assessed.

RESULTS

In total, 271 patients were included, of whom 208 (77%) developed recurrence. Receiver operating characteristic analysis demonstrated that a relative increase in postoperative serum CA19-9 of 2.6× was predictive of recurrence, with 58% sensitivity, 83% specificity, 95% positive predictive value, and 28% negative predictive value. The AUC for a 2.6× relative increase in the CA19-9 level was 0.719 in the training set and 0.663 in the test set. The AUC of postoperative CA19-9 as a continuous value (optimal threshold, 52) was 0.671 in the training set. In the training set, the detection of a 2.6-fold increase in CA19-9 preceded the detection of recurrence by a mean difference of 7 months ( P <0.001) and in the test set by 10 months ( P <0.001).

CONCLUSIONS

A relative increase in the postoperative serum CA19-9 level of 2.6-fold is a stronger predictive marker for recurrence than a continuous CA19-9 cutoff. A relative CA19-9 increase can precede the detection of recurrence on imaging for up to 7 to 10 months. Therefore, CA19-9 dynamics can be used as a biomarker to guide the initiation of recurrence-focused treatment.

Globo H ceramide is an independent prognostic marker for gallbladder cancer

In recent studies, there has been growing interest in developing cancer therapeutics targeting Globo H ceramide, which is considered as the most prevalent tumor-associated carbohydrate antigen in epithelial cancers. In this study, we aimed to evaluate the expression of Globo H and investigate its prognostic significance in gallbladder cancer (GBC). The tumor specimens and clinical characteristics of GBC patients were collected from the tumor bank and database of Chang Gung Memorial Hospital. Globo H in tumor specimens was detected by immunohistochemistry (IHC) and mass spectrometry analysis. Through data mining, it was discovered that FUT1 and FUT2, which are key enzymes involved in the biosynthesis of Globo H, were significantly up-regulated in human gallbladder cancer (GBC). Consistent with this finding, Globo H expression was detected in 86% (128 out of 149) of GBC specimens using immunohistochemical (IHC) staining. This was the highest frequency among Globo H expressing cancers. Patients with tumors exhibiting higher Globo H expression (H-score ≥ 80) demonstrated significantly shorter disease-free survival (DFS) and overall survival (OS) (P = 0.0001 and P = 0.0004, respectively). In a multivariable Cox regression analysis, elevated Globo H expression was identified as an independent unfavorable predictor for DFS and OS (hazard ratio: 2.29 and 2.32, respectively, P = 0.008 and 0.001) in primary GBC. Globo H is an independent prognostic marker for GBC.

EGFR is a potential therapeutic target for highly glycosylated and aggressive pancreatic neuroendocrine neoplasms

pNENs are relative indolent tumors with heterogeneous clinical presentation at diagnosis. It is important to establish aggressive subgroups of pNENs and identify potential therapeutic targets. Patients with pNEN (322 cases) were included to examine the association between glycosylation biomarkers and clinical/pathological traits. The molecular and metabolic features stratified by glycosylation status were assessed by RNA-seq/whole exome sequencing and immunohistochemistry. A considerable proportion of patients had elevated glycosylation biomarkers (carbohydrate antigen [CA] 19-9, 11.9%; CA125, 7.5%; carcinoembryonic antigen [CEA], 12.8%). CA19-9 (hazard ratio [HR] = 2.26, P = .019), CA125 (HR = 3.79, P = .004) and CEA (HR = 3.16, P = .002) were each independent prognostic variables for overall survival. High glycosylation group, defined as pNENs with elevated level of circulating CA19-9, CA125 or CEA, accounted for 23.4% of all pNENs. High glycosylation (HR = 3.14, P = .001) was an independent prognostic variable for overall survival and correlated with G3 grade (P < .001), poor differentiation (P = .001), perineural invasion (P = .004) and distant metastasis (P < .001). Epidermal growth factor receptor (EGFR) was enriched in high glycosylation pNENs using RNA-seq. EGFR was expressed in 21.2% of pNENs using immunohistochemistry and associated with poor overall survival (P = .020). A clinical trial focusing on EGFR expressed pNENs was initiated (NCT05316480). Thus, pNEN with aberrant glycosylation correlates with a dismal outcome and suggests potential therapeutic target of EGFR.

A Contemporary Review of the Treatment of Medullary Thyroid Carcinoma in the Era of New Drug Therapies

Medullary thyroid cancer (MTC) is a rare neuroendocrine tumor that can be sporadic or inherited and is often associated with mutations in the RET (Rearranged during Transfection) oncogene. The primary treatment for MTC is surgical resection of all suspected disease, but recent advances in targeted therapies for MTC, including the selective RET inhibitors selpercatinib and pralsetinib, have led to changes in the management of patients with locally advanced, metastatic, or recurrent MTC. In this article, we review updates on the evaluation and management of patients with MTC, focusing on new and emerging therapies that are likely to improve patient outcomes.

Other markers of medullary thyroid cancer, not only calcitonin

BACKGROUND

Medullary thyroid cancer (MTC) is a rare neuroendocrine tumor originating from parafollicular C-cells. It represents 2% of all thyroid malignancies and 0.4-1.4% of all thyroid nodules. MTC has a variable clinical course, with complete remission often difficult to achieve. An early diagnosis is still crucial in MTC management, enabling a radical surgical treatment, the only chance for curing the patient. Calcitonin (Ct) is a very sensitive MTC tumor marker in patients with thyroid nodules, although Ct-negative MTCs have been described, but not all clinical guidelines recommend the Ct routine measurement in thyroid nodules because of the absolute low prevalence of MTC in the general population and the consequent scarce positive predictive value of Ct. Moreover, the specificity of moderately high Ct levels is not high. Thus, the scientific community has been investigating the possible role of other tumor markers for MTC diagnosis and prognosis.

AIM OF THE REVIEW

The present review is an attempt to summarize the knowledge available today on the role of other serum markers for MTC alternative to Ct.

CONCLUSIONS

At present, literature data does not seem solid enough yet to establish effective flowcharts in evaluating a thyroid nodule for MTC, involving alternative serum markers, particularly in cases of moderately high CT levels. MTC is a rare diagnosis in thyroid nodules, and this makes the evaluation of any tumor serum marker accuracy problematic. More extensive and prospective studies are needed to shed more light on this intriguing challenge.

Machine learning algorithms to predict atypical metastasis of colorectal cancer patients after surgical resection

Background

The prognosis of colorectal cancer with atypical metastasis is poor. However, atypical metastasis was less common and under-appreciated.

Methods

In this study we attempted to present the first machine learning models to predict the risk of atypical metastasis in colorectal cancer patients. We evaluated the differences between metastasis and non-metastasis groups, assessed factors associated with atypical metastasis using univariate and multivariate logistic regression analyses, and preliminarily developed the multiple machine learning models to predict atypical metastasis.

Results

168 patients were included. Prognostic Nutritional Index (PNI) [OR =  0.998; P = 0.030], Cancer antigen 19-9 (CA19-9) [OR = 1.011; P = 0.043] and MR-Distance [-mid OR = 0.289; P = 0.009] [-high OR = 0.248; P = 0.021] were shown to be independent risk factors for the atypical metastasis via multivariate analysis. Furthermore, the machine learning model based on AdaBoost algorithm (AUC: 0736) has better predictive performance comparing to Logistic Regression (AUC: 0.671) and KNeighbors Classifier (AUC: 0.618) by area under the curve (AUC) in the validation cohorts. The accuracy, sensitivity, and specificity of the model trained using the Adaboost method in the validation set are 0.786, 0.776 and 0.700, while 0.601, 0.933, 0.508 using Logistic Regression and 0.743, 0.390, 0.831 using KNeighbors Classifier.

Conclusion

Machine-learning approaches containing PNI, CA19-9 and MR-Distance show great potentials in atypical metastasis prediction.

Medullary thyroid cancer - An update

Medullary thyroid cancer (MTC) is a rare neuroendocrine disease, encompassing about 5% of all thyroid cancers. Due to its peculiar features, this rare tumour offers unique possibilities for translational research studies. It arises from neuroendocrine parafollicular cells in an endocrine organ, and appears as a nodule apparently indistinguishable from thyroid nodules. It has a very peculiar progression with micro metastases difficult to identify, often-remaining stable during years and suddenly undergoing a rapid and unrestrainable progression. Moreover, MTC is one of the neoplasms with the best genetic characterization either in its sporadic or familial form, providing a valuable background to test targeted drugs. In the era of precision medicine, this review aims to give an update on the diagnostic tools, the therapeutic options for advanced MTC, and the most promising opportunities for a personalized follow up.

Metastatic papillary thyroid carcinoma presenting with elevated serum levels of carbohydrate antigen 19-9 (CA19-9): a case report

BACKGROUND

The major sites of distant metastases of papillary thyroid carcinoma (PTC) are the lung and bone; metastasis to the liver is rare. Although the postoperative serum thyroglobulin (Tg) level after total thyroidectomy is a good prognostic indicator for PTC when anti-thyroglobulin antibody (TgAb) is negative, the presence of TgAb interferes with the Tg assay, making serum Tg levels unreliable. Here we report a case of liver metastasis of PTC that presented with elevated serum levels of carbohydrate antigen 19-9 (CA19-9), which is usually a serum marker of pancreatic and gastrointestinal neoplasias.

CASE PRESENTATION

A 69-year-old man was diagnosed with PTC and underwent total thyroidectomy 16 years ago. The patient's serum Tg levels increased progressively during follow-up and his serum TgAb was negative. Positron emission tomography (PET) and computed tomography (CT) revealed metastases of the lung, cervical spine, mediastinum and liver. The liver lesion was a solitary tumor measuring 4.0 cm in the greatest dimension. His serum CA19-9 level was very high (326 U/mL), and intrahepatic cholangiocarcinoma was suspected from the results of various examinations including gastrointestinal endoscopic imaging and CT. Laparoscopic partial liver resection for segment 4 was performed. The histopathological diagnosis was a metastatic liver tumor from PTC. The immunohistological examination revealed that the liver tumor was positive for CA19-9 and Tg. The primary PTC, recovered from paraffin-embedded specimen, was also positive for CA19-9. After the surgery, his serum CA19-9 level as well as serum Tg level markedly decreased.

CONCLUSIONS

We presented the first reported case of liver metastasis of a PTC presenting with elevated serum levels of CA19-9 after total thyroidectomy. This case suggests that the serum CA19-9 levels may serve as a surrogate marker for PTC in place of the serum Tg level in patients with positive serum TgAb if the PTC and/or the metastatic lesions are positive for CA19-9 staining.

Adjusted association between type 2 immunity and low risk thyroid nodules: a retrospective cohort study

BACKGROUND

Immune responses, especially type 2 immunity, might be related to the prevalence of thyroid nodules, while the key regulators and potential pathways are remaining largely unknown. In addition, the immune status of individuals could be affected by mixed metabolic background. Herein our aim was to investigate the adjusted association between ultrasound-diagnosed low risk thyroid nodules and immune responses, excluding the interference of metabolic effects on immunity.

METHODS

We retrospectively enrolled 1764 subjects who underwent a thorough thyroid ultrasound examination. To eliminate the interference of confounders, we used propensity score matching (PSM) to match age, gender, cigarette smoking and alcohol drinking, parameters that are related with metabolic syndrome (MetS). Then the potential effectors of immune responses involved in the laboratorial assays were evaluated. Binary logistic regression analysis was used to assess the independent predictors of thyroid nodules in a multivariate manner.

RESULTS

The 1172 subjects were remained after PSM, and differences of demographic background between subjects with and without thyroid nodules were eliminated. Metabolic parameters comprising blood pressure, fasting blood glucose, total cholesterol, triglyceride, high-density lipoprotein, low-density lipoprotein and serum uric acid were shown no significant difference between post-PSM subjects with and without thyroid nodules. Among the biochemistry and hematological parameters, white blood cell count and the positive rate of eosinophil percentage were increased in subjects with thyroid nodules than in those without thyroid nodules. In contrast, the positive rate of basophil percentage was lower in subjects with thyroid nodules than in those without thyroid nodules. In addition, the thyroid function test results showed that subjects with thyroid nodules had higher positive rates of antithyroglobulin antibody (TgAb) and antithyroid peroxidase antibody (TPOAb) than subjects without thyroid nodules. The logistic regression analysis indicated that the positive value of TgAb as well as high level of white blood cell count and BMI could serve as independent risk factors of thyroid nodules.

CONCLUSIONS

The type 2 immune responses mediated by increased level of eosinophils, along with positive value of TgAb and TPOAb were associated with the presence of thyroid nodules. In addition, the potential role of basophils in protecting against thyroid nodules and the pathogenesis of immune-metabolic status remains to be elucidated.

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.

Ca19.9 Positivity and Doubling Time Are Prognostic Factors of Mortality in Patients with Advanced Medullary Thyroid Cancer with No Evidence of Structural Disease Progression According to Response Evaluation Criteria in Solid Tumors

Background: Serum Ca19.9 positivity is a prognostic factor for mortality in patients with advanced medullary thyroid cancer (aMTC), independently from calcitonin doubling time (DT). However, it is unknown whether aMTC patients who become positive for Ca19.9 also have progressive disease (PD) according to response evaluation criteria in solid tumors (RECIST) and whether Ca19.9 DT has a role in the management of aMTC patients. The aims of this study were to evaluate whether in aMTC, when serum Ca19.9 becomes positive, PD develops, and to determine the role of Ca19.9 DT in predicting mortality and PD. Patients and Methods: Serum Ca19.9 was periodically measured in 107 aMTC patients, and the DTs were calculated. Restaging of the disease was radiologically performed in 104 of 107 patients and PD was evaluated according to RECIST. Results: At the end of follow-up, 25 of 107 patients were Ca19.9 positive and PD was identified in 30 of 104 patients. No significant association was found between Ca19.9 positivity and PD, while there was a significant association between Ca19.9 positivity and mortality (p < 0.0001). Ca19.9 DTs <6 months and <1 year were not associated with PD but were associated with mortality (p < 0.0001 and p < 0.0001, respectively). In particular, 3 patients who had a Ca19.9 DT <6 months with no evidence of PD according to RECIST died of their disease after 6, 5, and 3 months, respectively. Conclusions: Serum Ca19.9 positivity and DTs <6 months and <1 year are prognostic factors for mortality but not for PD. Serum Ca19.9 positivity and DTs <6 months and <1 year should be considered in the decision-making process of whether to initiate systemic therapy even if there is no evidence of PD according to RECIST.

Roles of CA19-9 in pancreatic cancer: Biomarker, predictor and promoter

Carbohydrate antigen 19-9 (CA19-9) is the best validated biomarker and an indicator of aberrant glycosylation in pancreatic cancer. CA19-9 functions as a biomarker, predictor, and promoter in pancreatic cancer. As a biomarker, the sensitivity is approximately 80%, and the major challenges involve false positives in conditions of inflammation and nonpancreatic cancers and false negatives in Lewis-negative Individuals. Lewis antigen status should be determined when using CA19-9 as a biomarker. CA19-9 has screening potential when combined with symptoms and/or risk factors. As a predictor, CA19-9 could be used to assess stage, prognosis, resectability, recurrence, and therapeutic efficacy. Normal baseline levels of CA19-9 are associated with long-term survival. As a promoter, CA19-9 could be used to evaluate the biology of pancreatic cancer. CA19-9 can accelerate pancreatic cancer progression by glycosylating proteins, binding to E-selectin, strengthening angiogenesis, and mediating the immunological response. CA19-9 is an attractive therapeutic target for cancer, and strategies include therapeutic antibodies and vaccines, CA19-9-guided nanoparticles, and inhibition of CA19-9 biosynthesis.

Carbohydrate antigen 19-9 - tumor marker: Past, present, and future

Carbohydrate antigen 19-9 (CA 19-9) is a cell surface glycoprotein complex most commonly associated with pancreatic ductal adenocarcinoma (PDAC). Koprowski first described it in 1979 using a mouse monoclonal antibody in a colorectal carcinoma cell line. Historically, it is one of the most commonly used tumor markers for diagnosing, managing, and prognosticating PDAC. Additionally, elevated CA 19-9 levels are used as an indication for surgery in suspected benign pancreatic conditions. Another common application of CA 19-9 in the biliary tract includes its use as an adjunct in diagnosing cholangiocarcinoma. However, its clinical value is not limited to the hepatopancreatobiliary system. The reality is that the advancing literature has broadened the clinical value of CA 19-9. The potential value of CA 19-9 in patients' workup extends its reach to gastrointestinal cancers - such as colorectal and oesophageal cancer - and further beyond the gastrointestinal tract - including urological, gynecological, pulmonary, and thyroid pathologies. Apart from its role in investigations, CA 19-9 presents a potential therapeutic target in PDAC and acute pancreatitis. In a bid to consolidate its broad utility, we appraised and reviewed the biomarker's current utility and limitations in investigations and management, while discussing the potential applications for CA 19-9 in the works for the future.

The tissue expression pattern of CA 19.9 is associated with oncological features in medullary thyroid carcinoma

PURPOSE

Elevated serum levels of carbohydrate antigen 19.9 (CA19.9), a well-established tumor marker in pancreatic neoplasms, has been proposed as a prognostic marker of tumor aggressiveness in medullary thyroid carcinoma (MTC). A hypothesis of C-cell dedifferentiation has been raised. Here, we evaluated the expression of CA19.9 and CD133, a stem cell marker, in MTC tissues.

METHODS

MTC samples from patients attending a university-based hospital were evaluated for CA19.9 and CD133 expression by immunohistochemistry. Clinical data were retrieved from medical records.

RESULTS

Tumor specimens from 70 MTC patients (57.1% hereditary) were evaluated. The age at diagnosis was 36.1 ± 16.3 years, and 58.6% were female; 53% of patients had cervical and 20% distant metastases. CA19.9 staining was detected in 87% of the samples, but no association was observed with biochemical markers, tumor size, local or distant metastases (All P > 0.05). Remarkable, CA19.9 expression was higher in the metastasis than in primary tumor samples (P = 0.0002). CD133 was expressed in 90.5% samples, but no correlation was found with CA19.9. Interestingly, we identified three distinct expression patterns to CA19.9: individual, focal, and diffuse cells. Sporadic MTC was associated with the individual cell pattern (70.6%), while the hereditary form with the focal expression pattern (63.9%; P = 0.04). Remarkably, the diffuse pattern was associated with larger tumor size and distant metastases (P = 0.032).

CONCLUSIONS

The majority of samples stained for CA19.9, suggesting it is an MTC cell-intrinsic feature. Three distinct expression patterns were identified, which were associated with the hereditary or sporadic form, larger tumor size, and presence of metastases.

Carcinoembryonic antigen should be concurrently checked with calcitonin to identify distant metastases in medullary thyroid cancer

Aim: This study investigates if serum calcitonin or carcinoembryonic antigen (CEA) levels can differentiate between locoregional and metastatic medullary thyroid cancer. Methods: A single institution retrospective analysis was performed on 88 patients with medullary thyroid cancer between 2008 and 2014. Results: In M0disease, calcitonin (p < 0.001) and CEA (p = 0.003) significantly decreased postoperatively. Not only was the correlation significant between calcitonin and CEA preoperatively (r = 0.72; p < 0.001) and postoperatively (r = 0.68; p < 0.001), calcitonin could extrapolate CEA levels (p < 0.001). These findings were statistically insignificant in metastatic disease. Conclusion: Independently, calcitonin and CEA fail to differentiate between locoregional and metastatic disease. Both are essential for prognostication: loss of concordance is suspicious for metastatic disease. Hence, discordant CEA and calcitonin levels should be an indication to pursue additional imaging.