Tumor markers in cancer diagnosis and prognosis

A novel aptasensor platform for the detection of carcinoembryonic antigen using quartz crystal microbalance

In this study, a quartz crystal microbalance (QCM) aptasensor for carcinoembryonic antigen (CEA), a well-known biomarker for various cancer types, was reported, utilizing two different aptamers. To achieve this, a nanofilm of 4-mercaptophenyl was electrochemically attached to gold-coated QCM crystal surfaces via the reduction of 4-mercaptobenzenediazonium salt (4 MB-DAT) using cyclic voltammetry. Subsequently, gold nanoparticles (AuNP) were affixed to this structure, and then aptamers (antiCEA1 and antiCEA2) modified with SH-functional ends bound to AuNPs completed the modification. The analytical performance of the CEA sensor was evaluated through simultaneous QCM measurements employing CEA solutions ranging from 0.1 ng/mL to 25 ng/mL. The detection limit (LOD) for CEA was determined to be 102 pg/mL for antiCEA1 and 108 pg/mL for antiCEA2 aptamers. Interday and intraday precision and accuracy tests yielded maximum results of 4.3 and + 3.8, respectively, for both aptasensors, as measured by relative standard deviation (RSD%) and relative error (RE%). The kinetic data of the aptasensors resulted in affinity values (KD) of 0.43 ± 0.14 nM for antiCEA1 and 0.75 ± 0.42 nM for antiCEA2. These values were lower than the reported values of 3.9 nM and 37.8 nM for both aptamers, respectively. The selectivity of the aptasensor was evaluated by measuring the signal changes caused by alpha-fetoprotein (AFP), cancer antigen (CA-125), and vascular endothelial growth factor (VEGF-165) individually and together at a concentration of 500 ng/mL, resulting in a maximum 4.1 % change, which was comparable to precision and accuracy values reported in the literature. After confirming the selectivity of the aptamers, recovery experiments were conducted using spiked commercial serum samples to simulate real samples, and the lowest recovery value obtained was 95.4 %. It was determined that two different aptasensors could be successfully used for the QCM-based detection of CEA in this study.

A facile electrochemical immunosensor based on EDTA-Pb2+ complexation reaction

The sensitivity of electrochemical (EC) sensors has been improved through the development of multiple approaches. However, the majority of EC sensors were limited in their practical application by high costs or tedious procedures. Herein, based on ethylenediaminetetraacetic acid (EDTA)-Pb2+ complexation reaction, a facile and affordable immunosensor was designed. Pb2+-magnesium silicate hydrate was served as the sensing substrate. The immunorecognition process was carried out in the Eppendorf tube, and antibody-functionalized Pb2+-polydopamine was utilized as immunoprobe. In the tube, the quantitative and appropriate excess of EDTA was introduced to complex with Pb2+ on the immunoprobes. The remaining EDTA was added to the sensing substrate surface to coordinate with some Pb2+ in it. This leaded to the reduction of the EC signal of Pb2+, which was related to the antigen concentration. Using prostate-specific antigen as the model analyte, the sensitive detection was realized with a low limit of detection (30.49 fg mL-1). Remarkably, the assay results were available within 24 min, sensibly faster than the most existing EC sensors.

The Optimal Cutoff Value of Tumor Markers for Prognosis Prediction in Ampullary Cancer

BACKGROUND

Carbohydrate antigen 19-9 (CA 19-9) is a representative tumor marker used for the diagnosis of pancreatic and biliary tract cancers. There are few published research results that can be applied to actual clinical practice for ampullary cancer (AC) alone. This study aimed to demonstrate the relationship between the prognosis of AC and the level of CA 19-9, and to determine the optimal thresholds.

METHODS

Patients who underwent curative resection (pancreaticoduodenectomy (PD) or pylorus preserving pancreaticoduodenectomy (PPPD)) for AC at the Seoul National University Hospital between January 2000 and December 2017 were enrolled. To determine the optimal cutoff values that could clearly stratify the survival outcome, the conditional inference tree (C-tree) method was used. After obtaining the optimal cutoff values, they were compared to the upper normal clinical limit of 36 U/mL for CA 19-9. Results In total, 385 patients were enrolled in this study. The median value of the tumor marker CA 19-9 was 18.6 U/mL. Using the C-tree method, 46 U/mL was determined to be the optimal cutoff value for CA 19-9. Histological differentiation, N stage, and adjuvant chemotherapy were significant predictors. CA 19-9 36 U/mL had marginal significance as a prognostic factor. In contrast, the new cutoff value, CA 19-9 46 U/mL, was found to be a statistically significant prognostic factor (HR: 1.37, p = 0.048).

CONCLUSIONS

The new cutoff value of CA 19-9 46 U/mL may be used for evaluating the prognosis of AC. Therefore, it may be an effective indicator for determining treatment strategies such as surgical treatments and adjuvant chemotherapy.

Chondroitin Sulfate Proteoglycan 4 as a Marker for Aggressive Squamous Cell Carcinoma

Chondroitin sulfate (CS) proteoglycan 4 (CSPG4) is a cell surface proteoglycan that is currently under investigation as a marker of cancer malignancy, and as a potential target of anticancer drug treatment. CSPG4 acts as a driver of tumourigenesis by regulating turnover of the extracellular matrix (ECM) to promote tumour cell invasion, migration as well as inflammation and angiogenesis. While CSPG4 has been widely studied in certain malignancies, such as melanoma, evidence is emerging from global gene expression studies, which suggests a role for CSPG4 in squamous cell carcinoma (SCC). While relatively treatable, lack of widely agreed upon diagnostic markers for SCCs is problematic, especially for clinicians managing certain patients, including those who are aged or infirm, as well as those with underlying conditions such as epidermolysis bullosa (EB), for which a delayed diagnosis is likely lethal. In this review, we have discussed the structure of CSPG4, and quantitatively analysed CSPG4 expression in the tissues and pathologies where it has been identified to determine the usefulness of CSPG4 expression as a diagnostic marker and therapeutic target in management of malignant SCC.

Prognostic Value of Carcinoembryonic Antigen (CEA) and Carbohydrate Antigen 19-9 (CA 19-9) in Gallbladder Cancer; 65 IU/mL of CA 19-9 Is the New Cut-Off Value for Prognosis

Simple Summary

Gallbladder cancer (GBC) is the fifth most common cancer of the digestive tract, and preoperative tumor markers for GBC have been studied as a less invasive way to detect the presence of the cancer. CEA and CA 19-9 have been most commonly used for detecting GBC clinically, and various cut-off values were suggested to satisfy this purpose, but there has still been a lack of proper values of these tumor markers to predict the prognosis of GBC. We have aimed to suggest appropriate cut-off values that could help to anticipate prognosis in the preoperative period. Data from carefully selected 539 patients were used in our study, the new cut-off value, 65 IU/mL for CA 19-9 was derived through an up-to-date statistical method. By using this cut-off value, clinicians could get the important reference in the establishment of the strategy of treatment, and the researches about this topic could become more vigorous.

Abstract

Due to the lack of appropriate tumor markers with optimal cut-off values to predict the prognosis of gallbladder cancer (GBC), this study aimed to demonstrate the relationship between prognosis and the levels of carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA 19-9), and to determine optimal thresholds. In total, 539 patients diagnosed with GBC were examined. The relationship between tumor marker levels and overall survival (OS) was analyzed. The C-tree method was used to suggest tumor marker thresholds, and multivariate analysis was conducted to identify prognostic factors for overall survival. The mean age of the patients was 65.3 years, and the 5-year overall survival rate in all patients was 68.9%. Following the C-tree method, the optimal cut-off value was set at 5 IU/mL for CEA and at 65 IU/mL for CA 19-9. Multivariate analysis revealed that age, CA 19-9 level, operative method, T stage, and N stage were significant prognostic factors for OS. Consequently, CA 19-9 had a stronger association with prognosis than CEA, and 65 IU/mL for CA 19-9 may be suggestive in evaluating the prognosis of GBC. Moreover, it could be an effective indicator for determining the surgical extent necessary and the need for adjuvant treatment.

New immunoprobe: Dual-labeling ZIF-8 embellished with multifunctional bovine serum albumin lamella for electrochemical immunoassay of tumor marker

A new immunoprobe, which can initiate the sedimentation of Ag nanoparticles (NPs) on an electrode surface, was developed for the electrochemical detection of carbohydrate antigen 72-4 (CA 72-4). To design the immunoprobe, zeolitic imidazolate frameworks (ZIFs) were employed as the carrier to enrich thionine molecules, then bovine serum albumin (BSA) was modified on the electrode surface. Advantageously, BSA, served as an anchor to further attach the labeling antibodies (Ab₂) and alkaline phosphatase (ALP) to also be modified on the surface through covalent bonding. To construct the immunosensor, multiwalled carbon nanotube-graphene oxide composites were employed to provide active sites, and the electrodeposited Au NPs were used to immobilize coating antibodies. In the presence of CA 72-4, a sandwich immunosensor was established, and a cascade reaction was initiated to deposit Ag NPs under the catalysis, which can further improve the conductivity of electrode interface. Under the optimal conditions, the immunosensor displayed excellent performance with a wide linear range from 1 μU mL^-1 to 10 U mL^-1 and an ultralow detection limit of 0.438 μU mL^-1 (S/N = 3).

Platinum Nanozyme-Triggered Pressure-Based Immunoassay Using a Three-Dimensional Polypyrrole Foam-Based Flexible Pressure Sensor

This work describes a novel and portable pressure-based point-of-care (POC) testing strategy for the sensitive and rapid detection of carcinoembryonic antigen (CEA) via a flexible pressure sensor constructed by three-dimensional (3D) polypyrrole (PPy) foam. Initially, platinum nanoparticles (PtNPs) were conjugated to the detection antibodies, which were used to form sandwich-type immunocomplexes with targets and capture antibodies in the reaction cell. Then, the carried PtNPs catalyzed the dissociation of hydrogen peroxide (H₂O₂) for the generation of oxygen (O₂) in a sealed device, translating the biomolecule recognition event into gas pressure. With the increase of pressure, a flexible pressure sensor with 3D polypyrrole foam as the sensing layer was used to sensitively monitor the pressure variations in this system. Thus, the concentration of the target could be quantitatively determined by the pressure response. Under optimal conditions, the pressure-based immunosensor showed good sensing performance for CEA in the dynamic working range from 0.2 to 60 ng/mL with a detection limit of 0.13 ng/mL. The reproducibility, specificity, and accuracy compared with commercial enzyme-linked immunosorbent assay (ELISA) kit were also acceptable. Therefore, this work provides a promising approach for developing portable and sensitive POC testing in the future.

The emergence of trophoblast cell-surface antigen 2 (TROP-2) as a novel cancer target

TROP-2 is a glycoprotein first described as a surface marker of trophoblast cells, but subsequently shown to be increased in many solid cancers, with lower expression in certain normal tissues. It regulates cancer growth, invasion and spread by several signaling pathways, and has a role in stem cell biology and other diseases. This review summarizes TROP-2's properties, especially in cancer, and particularly its role as a target for antibody-drug conjugates (ADC) or immunotherapy. When the irinotecan metabolite, SN-38, is conjugated to a humanized anti-TROP-2 antibody (sacituzumab govitecan), it shows potent broad anticancer activity in human cancer xenografts and in patients with advanced triple-negative breast, non-small cell and small-cell lung, as well as urothelial cancers.

Carbohydrate Antigen 19-9, Carcinoembryonic Antigen, and Carbohydrate Antigen 72-4 in Gastric Cancer: Is the Old Band Still Playing?

Background

Gastric cancer (GC) is characterized by aggressive behavior and a high mortality rate. The diagnosis of GC is challenging because the GC is often diagnosed in an advanced stage. The use of tumor markers is a putative way to improve the detection and treatment in patients with GC.

Summary

In this article, we review the significance of serum carbohydrate antigen (CA) 19-9, carcinoembryonic antigen (CEA), and CA 72-4 in GC. The results from different studies regarding the diagnostic and prognostic role of CA 19-9, CEA, and CA 72-4 in GC are encouraging, but inadequate sensitivity and specificity obstruct their use as standardized and unconditionally reliable markers in GC. New prospective clinical trials are mandatory for clarifying their value in GC.

Key Message

CA 19-9, CEA, and CA 72-4 should not be used for screening and early diagnosis in GC, whereas they are beneficial in the detection of late GC. CA 19-9, CEA, and CA 72-4 could be used as prognostic and monitoring tools in GC, and their combined measurement in shorter periods of time is the best method to increase sensitivity and specificity.

Practical Implications

Serum CA 19-9, CEA, and CA 72-4 are useful diagnostic and prognostic tumor markers in GC.

Simultaneous Determination of Urinary CEA, Ferritin and TPA in Egyptian Bladder Cancer Patients

Urinary carcinoembryonic antigen (CEA), ferritin (Fer) and tissue polypeptide antigen (TPA) were determined in 328 cases (106 with blader cancer, 152 with non-malignant urinary tract disease and 70 healthy controls). CEA was determined by the kit supplied by Roche Diagnostica (CEA EIA Doumab 60), ferritin by the Tandem-E Fer kit supplied by Hybritech and TPA by the Prolifigen TPA-IRMA kit supplied by Sangtec Medical. The results of this work revealed that combined determination of urine CEA and Fer, CEA and TPA or Fer and TPA showed higher sensitivity than determination of the individual markers. There was no significant difference between combined and individual marker determination with respect to false positivity in non-malignant urinary tract diseases. At 97% specificity, the sensitivities of urine CEA, Fer and TPA were 82.1%,71.7% and 90.6%, respectively, while combined urine CEA & Fer, CEA & TPA and Fer & TPA showed sensitivities of 92.5%, 99.1% and 98.1%, respectively. When the specificity was related to the entire non-cancer group (patients with benign urinary tract diseases and normal controls), some reduction in the sensitivities of the combined markers was noted compared to the normal group only.

In conclusion, combined determination of urine markers is superior to determination of individual markers in the diagnosis of bladder cancer

Plasmonic ELISA based on the controlled growth of silver nanoparticles

Herein, we demonstrate a plasmonic ELISA based on the alkaline phosphatase (ALP)-mediated growth of silver nanoparticles (AgNPs) for the sensitive, rapid, and naked-eye detection of cancer biomarkers in clinical serum samples. This approach was used to measure the low-abundance alpha fetal protein (AFP) in clinical sera, which demonstrates its great capability in the differentiation of cancers and evaluation of therapeutic responses. Impressively, the readout of the plasmonic assay depends on the rapid formation of Ag colloidal solutions with various degrees of yellow color, which can be distinguished by the naked eye, without the need for sophisticated platforms. The limit of detection of the plasmonic ELISA for alpha fetal protein (AFP) can be as low as 0.23 ng mL^-1, which is approximately 10 folds lower than that of conventional ELISA. This plasmonic ELISA opens a new avenue for the early detection of cancers and monitoring of cancer reoccurrence especially in resource-poor regions where convenient diagnostic tools are highly desirable.

Efficient electrochemiluminescence quenching of carbon-coated petalous CdS nanoparticles for an ultrasensitive tumor marker assay through coreactant consumption by G-quadruplex-hemin decorated Au nanorods

A novel competitive electrochemiluminescence aptasensor was designed for the detection of carcinoembryonic antigen using carbon-coated petalous CdS nanopaticles as an ECL emitter and DNAzyme/Au nanorods–complementary DNA as a quenching probe.

Serum Tumor Marker Use in Patients With Advanced Solid Tumors

PURPOSE

There is substantial variability in the frequency of serum tumor marker testing in patients with advanced solid tumors. We performed a retrospective analysis to evaluate the frequency of serum tumor marker use.

METHODS

Patients with a diagnosis of advanced cancer with outpatient visits between July 1, 2013, and June 30, 2014, at a single center were included. Tumor and stage were determined by International Classification of Diseases, Ninth Revision codes and confirmed with tumor registry and medical record review. For each patient, we recorded the dates of each of the following tumor markers: a-fetoprotein, CA-125, CA 15-3, CA 19-9, CA 27-29, and carcinoembryonic antigen. We evaluated the number of tests per patient over 12 months and the maximum number of tests per patient per month.

RESULTS

We included 928 patients in the analysis. The mean number of any individual test per patient was seven tests, and the maximum number was 35 tests; the mean number of total tests per patient was 12 tests, and the maximum number was 70 tests; 16.3% of patients had more than 12 individual tests per year. In a 1-month span, 34.3% of patients had more than one individual test. CA 19-9 and carcinoembryonic antigen were the most commonly overused tests.

CONCLUSION

We found a high rate of serum tumor marker testing use in patients with advanced solid tumors. Given the increasing costs of cancer care, efforts should be made to determine the benefit of serum tumor markers in the follow-up care of patients with advanced solid tumors.

Tumor markers: A diagnostic tool

The purpose of this review is to give a brief background to enable the judicious use of widely performed serum cancer markers. The markers could be product of cancerous cell or as response to cancer. They are usually proteins, which are mainly found in blood or urine. These markers may be employed to predict primary or secondary tumor risk. Sometimes, non-cancerous conditions can also cause elevation of some tumor markers to be higher than normal. Besides, not every cancer patient may have raised level of a tumor marker. For these reasons, knowledge about cancer biomarkers has increased tremendously. Awareness for cancer and related tumor markers providing great opportunities for improving the management of cancer patients by enhancing the efficiency of detection and efficacy of treatment.

Combining multiple serum biomarkers in tumor diagnosis: A clinical assessment

The present study aimed to assess the diagnostic/prognostic value of various clinical tumor markers, including carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), cytokeratin 19 (CYFRA21-1), α-fetoprotein (AFP), carbohydrate antigen-125 (CA-125), carbohydrate antigen-19.9 (CA-19.9) and ferritin, individually or in combination. The electro-chemiluminescence immunization method was performed to detect the levels of seven tumor markers in 560 cancer patients and 103 healthy subjects for comparison. The serum levels of the seven markers measured in cancer patients were higher compared to healthy subjects (P<0.05 for AFP and P<0.001 for the remaining six markers). Different markers had different sensitivity towards different types of tumors. Combining more markers significantly increased the ratios of positive diagnosis in the tumors. The diagnostic sensitivities of combining seven markers were particularly high in digestive, urinary and skeletal tumors (82, 92 and 83%, respectively). Gynecological tumors have exhibited a constant yet relatively low positive diagnosis irrespective of the use of a single marker or combined markers. However, the increase in sensitivity when combining markers was accompanied by a decrease in specificity. Generally, combining more markers increased the tumor detection rates, while a combination of the seven markers provided the highest detection rate. Combined detection showed a particularly high sensitivity in detecting respiratory, digestive and urinary system tumors, with the lowest sensitivity observed in gynecological tumors. As a result, combining tumor markers may play an important role in early tumor detection/diagnosis while the loss of specificity can be tolerated.

Huge immature teratoma of the liver in an adult: a case report and review of the literature

Teratoma tumors are tumors of childhood and, to the best of our knowledge, only 9 cases of hepatic teratoma and 1 case of immature teratoma of the liver had been reported in adults in the English literature. We present the second case of immature liver teratoma in a 22-year-old woman who presented with a 4-month history of abdominal pain and fullness sensation. A computed tomography (CT) scan of the abdomen and pelvis showed a huge well-defined heterogeneous mass in the right lobe of the liver containing fat, calcification, and cystic and solid parts, all suggestive of a teratoma. A right hepatectomy and an omentectomy were performed. The pathology report showed a 27 cm mass composed of ectodermal, mesodermal and endodermal components with minimal atypia and foci of immature components suggestive of immature teratoma, which is the largest liver teratoma to be reported. The patient was discharged in good health. During 8 months of follow-up, a CT scan and α-fetoprotein levels were both normal, and the patient is still alive.

Sacral intraspinal extradural primitive neuroectodermal tumor

BACKGROUND CONTEXT

Intraspinal primitive neuroectodermal tumors (PNETs) are an exceedingly rare entity. A recent literature research revealed 28 cases reported. Only a few tumors in the literature were extradural in location, in the cervical and thoracic spine. The average survival after combination treatment including chemotherapy, radiation, and surgical resection is 20 months for the cases reported in the literature.

PURPOSE

We report a case of a patient with sciatica and cauda equine-like symptoms.

STUDY DESIGN

Case report.

METHODS

Urgent sacral decompression and resection of the tumor was performed with rapid pain relief for the patient.

RESULTS

Histology revealed a sacral extradural small blue-cell tumor, consistent with ES/PNET family tumors. An oncological workup revealed that the tumor presentation was metastatic with pulmonary and abdominal nodules. The patient underwent combination chemotherapy with vincristine, doxorubicin, and cyclophosphamide with mesna for 4 months.

CONCLUSIONS

The patient was without disease after excision, two courses of 4-month chemotherapy, and one course of 5-week radiation to the sacrum at 2 years.

Disposable electrochemical immunosensor for carcinoembryonic antigen using ferrocene liposomes and MWCNT screen-printed electrode

Disposable electrochemical immunosensor for the detection of carcinoembryonic antigen (CEA) in saliva and serum was developed. Monoclonal anti-CEA antibodies (alphaCEA) were covalently immobilized on polyethyleneimine wrapped multiwalled carbon nanotubes screen-printed electrode. A sandwich immunoassay was performed with CEA and alphaCEA tagged ferrocene carboxylic acid encapsulated liposomes (alphaCEA-FCL). The square wave voltammetry (SWV) was employed to analyze faradic redox responses of the released ferrocene carboxylic acid from the immunoconjugated liposomes on the electrode surface. The magnitude of the SWV peak current was directly related to the concentration of CEA. The calibration curve for CEA concentration was in the range of 5 x 10(-12) to 5 x 10(-7)gmL(-1) with a detection limit of 1 x 10(-12)gmL(-1) (S/N=3). This method provides a high precise and sensitive determination of CEA in human blood serum and saliva samples.

Controlling tumor-derived and vascular endothelial cell growth: role of the 4Ff2 cell surface antigen

We have isolated a monoclonal antibody, clone betaE11, which recognizes an antigen that is highly abundant on the surface of mitotic vascular endothelial cells and tumor cells. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting, expression of this 190-kd antigen is approximately threefold higher in mitotic versus interphase endothelial cells. Treatment of tumor cells with an antibody to the betaE11 antigen inhibits their growth in a dose-dependent manner in vitro with maximal inhibition at an antibody concentration of 1 microg/ml. Different tumor cell lines demonstrate varying sensitivities to anti-betaE11 with the following order of growth inhibition: colon > prostate = glioma > melanoma = fibroblast > breast > liver. Furthermore, the betaE11 antigen localizes to regions of prostatic intraductal neoplasia in paraffin-embedded sections. Mass spectrometry of the cell-derived betaE11 protein and V8-protease fingerprint analysis indicate that the betaE11 antigen is nearly identical to the 4F2 heavy chain antigen, a cell surface protein that has been implicated in cell activation and proliferation. Expression of the betaE11 antigen during mitosis functionally links it to a fundamental aspect of cell proliferation, and its spatial localization on the surface of both proliferating endothelium and tumor cells demonstrates its potential for tumor immunotherapy.

Whole blood glutathione peroxidase activity in melanoma patients

We have studied whole blood glutathione peroxidase activity as a possible diagnostic factor or marker for detection and diagnosis of patients with melanoma. This activity was determined in 40 melanoma patients (MP) and in 40 healthy persons (HP) using an enzymatic method. We found a mean value of 17.90+/-6.82 units/ml in MP and 27.07+/-14.35 units/ml in HP. A very significant decrease in whole blood glutathione peroxidase activity was observed in MP in comparison to the enzymatic activity in HP (P = 0.0005). In order to check whether this test could discriminate between MP and HP, a complete statistical Receiver Operating Characteristic (ROC) curve analysis was performed. The cut-off value was 14.26 units/ml. The area under the curve was 0.737. According to these results, the test could discriminate adequately between both groups. However, the high specificity and low sensitivity values associated with that cut-off value would make this test a very valuable tool for confirming the detection, rather than for primary screening.

Serum tyrosine hydroxylase activity is increased in melanoma patients. An ROC curve analysis

We have studied the serum tyrosine hydroxylase activity of tyrosinase, the key enzyme in the melanogenesis via, as a possible diagnostic factor or marker for detection, prognosis and follow-up of patients with melanoma. This activity was determined in 30 melanoma patients (MP) and in 30 healthy persons (HP) by using a radiometric method. We found mean values of 10.8+/-3.0 and 7.65+/-2.32 mU/l for serum tyrosine hydroxylase activity in MP and HP, respectively. A very significant increase in serum tyrosine hydroxylase activity was observed in MP in comparison to the enzymatic activity in HP (P < 0.00001). Although these data seem very conclusive, we wanted to know whether this test could discriminate adequately between MP and HP. In order to reach this aim, a complete statistical study was performed by using receiver operating characteristic (ROC) curve analysis. The cut-off value obtained was 8.47 mU/l. According to our results and after analytical treatment of the data, we can confirm that evaluation of tyrosine hydroxylase activity in serum could be a quick and reliable diagnostic method for detection, prognosis and follow-up in melanoma patients.