Cancer

Posted: January 4th, 2023

TUMOR MARKERS

Name:

Course:

Professor’s Name:

University:

Date:

Table of Contents

Contents                                                                                                                     Page

Introduction. 3

The Common Tumor Markers in Screening for Cancer 3

Tumor Markers in Assessing Prognosis. 4

Tumor markers for Monitoring Systemic Therapy. 4

Advances in Tumor markers. 5

Conclusion. 6

References. 7

Tumor Markers

Introduction

Cancer is a debilitating disease that reduces the quality of life of an increasingly larger population and a leading cause of fatalities across the world. While advancements in medicine have improved the detection, treatment, and prevention of cancer, its prevalence in society is increasing. Tumor makers are a significant advancement in medical science that has improved the detection and management of cancer since their discovery in the 1960s (Kulasingam, Prassas, & Diamandis 2017). Tumor markers are biomarkers found in body fluids and tissues, including saliva, blood, urine, stool, and tissues, which become elevated in the presence of cancer, although they are also produced by non-cancerous cells. Tumor markers are classified as either tumor tissue markets or circulating tumor markets, which can be detected from tissue biopsies or liquid biopsies, respectively (Clarke & Marzinke 2020). An ideal tumor market should have high specificity and sensitivity to detect tiny tumors before they present their adverse health effects (Kabel 2017). Recent advancements in tumor marker research have focused on liquid biopsies, which are noninvasive compared to tissue biopsies. This discussion aims at explaining the different aspects of tumor markers, which are critical for diagnosis, prognosis, monitoring of treatment progress, and in turn, the prevention and management of cancer.

The Common Tumor Markers in Screening for Cancer

Several tumor markers are used to screen large populations for the presence of cancer. These markets are used to detect cancer in individuals that do not present any clinical symptoms. Screening can help detect cancer early and in turn, help in administering early intervention before the cancer progresses, spreads to other parts of the body, and caused fatalities. Several tumor markers as specifically used in mass screening of populations. These include fecal occult blood marker, which is used to detect invisible blood in stool, to indicate the presence of colorectal cancer, while gastric cancer is screened using pepsinogen marker. Prostrate cancer can be screened using the prostate-specific antigen (PSA) marker. Ovarian cancer is screened using cancer antigen 125 (CA 125) marker, while hepatocellular carcinoma can be screened using the α-Fetoprotein (AFP) marker, particularly in populations with a prevalence liver disease, and chronic hepatitis B and C.  

Tumor Markers in Assessing Prognosis

Tumor markers can be used to track the trajectory of cancer, predict response to medication, and forecast the likelihood of the cancer to worsen or lessen over time. Altogether, they can be used to predict the course of cancer and therefore, assist in the making of clinical decisions (Dakubo 2016). Several makers are in use for prognosis of different cancers. The prognosis of breast cancer can be assessed using oncotype DX, urokinase plasminogen activator (uPA) marker or the plaminogen activator inhibitor typ-1 (PAI-1) marker (Duffy et al. 2017). Similarly, the prognosis of prostrate and ovarian cancer can be appraised using prostate-specific antigen (PSA) marker and CA 125 marker, respectively, while that of germ cell carcinoma can be assessed using α-Fetoprotein (AFP) marker, human chorionic gonadotropin (hCG) marker or lactic acid dehydrogenase (LDH) marker (Dakubo 2016).

Tumor markers for Monitoring Systemic Therapy

In the oncological context, systemic therapy is a treatment regime that aims at ridding the entire body of cancerous cells. In this regard, medication that targets cancer wherever it is located in the body is administrated, usually as a follow-up to surgery to remove the cancerous tumors (Duffy et al. 2017). Immunotherapy, hormonal therapy, and chemotherapy are examples of systemic therapeutic strategies for cancer. Tumor markers can be used to monitor the effectiveness of the treatment strategy by identifying the presence or absence the cancerous cells based on their responses, which can be detected in body fluids, and especially blood (Dakubo 2016). In this regard, serum tumor markers are increasingly being used as monitors of systemic therapy, although tumor tissue markers are still in use in routine clinical practice (Dakubo 2016). For instance, progesterone receptor and estrogen receptor are tumor tissue markets for monitoring hormone therapy and specified target therapies for treating breast cancer (Duffy et al. 2017). In addition, Duffy (2017) reported that thyroglobulin, CA 125, PSA, CEA, and CA 15-3 are markers that were used to monitor the systemic therapy for thyroid cancer, ovarian cancer, prostrate cancer, colorectal cancer, and breast cancer, respectively.

Advances in Tumor markers

Tumor marker research is ongoing in earnest. It has delivered several advancements that are already in use or are still under test for their efficacy.  For instance, research has presented noninvasive management of cancer using circulating tumor markers that are used in liquid biopsies, which is a significant step from the conventional tissue biopsy that relies on tissue tumor markers (Dincer 2018). Li et al. (2019) reported that serum tumor markets, when used alongside circulating tumor cells analysis enabled the early detection of lung cancer. In the same vein, carcinoembyonic antigen (CEA) has gained popularity as a non-invasive biomarker and is commonly used as a marker for detecting colorectal cancer. However, antigen exists in the blood stream of normal adults in miniscule quantities, making the test to have low sensitivity (40-60%) despite its high specificity (Luo et al. 2020). Studies are ongoing in enhancing the sensitivity of serum tumor markers.

Recently, it has been discovered that circulating tumor DNA (ctDNA) that is derived from fragmented dead tumor cells can be used to increase the sensitivity of tumor markers by detecting DNA methylation, which is an early event in the lifecycle of tumors (Luo et al. 2020). In this regard, profiling ctDNA methylation is advantageous over somatic mutation analysis because it not only delivers higher test sensitivity but also a dynamic range of the tests and the identification of multiple targets, enhancing the detection of tumors (Luo et al. 2020). Li, et al. (2020) reported that these novel DNA methylation markers were effective in diagnosing lung adenocarcinoma early. Moreover, novel tumor markers are under test in the search for higher sensitivity and specificity. For example, Schmidt et al. (2020) reported that S100A8 and S100A9, which are proteins with low molecular weight, could be used as cancer biomarkers because they were expressed around tumor tissues and not around health ones.

Conclusion

Tumor markers have benefited oncology because they provide a scientific approach to the diagnosis and prognosis of cancer and its management strategies. The traditional tissue biopsies have been the gold standard diagnostic approach to cancer and have use tumor tissue markers in their application principle. However, liquid biopsies are gaining popularity as noninvasive procedures alongside their application in the early detection of cancerous tumors because they detect the tumor markers in circulation in body fluids rather than in cancerous tumors. The latest developments in tumor markers are focused on circulating tumor markers because they promise higher specificity and sensitivity, thus enabling preventative interventions rather than curative ones.

References

Clarke, W & Marzinke, M 2020, Contemporary practice in clinical chemistry, Academic Press.

Dakubo, GD 2016, Cancer biomarkers in body fluids: Biomarkers in circulation, Springer.

Dincer, Y 2018. Researches on new generation tumor markers. Nova Medicine and Health.

Duffy, MJ 2017, ‘Clinical use of tumor biomarkers: an overview’, Klin Biochem Metab, vol. 25, pp.157-161.

Duffy, MJ, Harbeck, N, Nap, M, Molina, R, Nicolini, A, Senkus, E & Cardoso, F 2017, ‘Clinical use of biomarkers in breast cancer: Updated guidelines from the European Group on Tumor Markers (EGTM)’, European Journal of Cancer, vol. 75, pp. 284-298.

Kabel, AM 2017, ‘Tumor markers of breast cancer: New prospectives’, Journal of Oncological Sciences, vol. 3, no. 1, pp. 5-11.

Kulasingam, V., Prassas, I & Diamandis, EP 2017, ‘Towards personalized tumor markers’, NPJ Precision Oncology, vol. 1, no. 1, pp.1-4.

Li, M, Zhang, C, Zhou, L, Li, S, Cao, YJ, Wang, L, Xiang, R, Shi, Y & Piao, Y 2020, ‘Identification and validation of novel DNA methylation markers for early diagnosis of lung adenocarcinoma’, Molecular Oncology, vol. 4, pp. 2744-2758.

Li, Y, Tian, X, Gao, L, Jiang, X, Fu, R, Zhang, T, Ren, T, Hu, P, Wu, Y, Zhao, P & Yang, D 2019, ‘Clinical significance of circulating tumor cells and tumor markers in the diagnosis of lung cancer’, Cancer Medicine, vol. 8, no. 8, pp. 3782-3792.

Luo, H, Zhao, Q, Wei, W, Zheng, L, Yi, S, Li, G, Wang, W, Sheng, H, Pu, H, Mo, H & Zuo, Z 2020, ‘Circulating tumor DNA methylation profiles enable early diagnosis, prognosis prediction, and screening for colorectal cancer’, Science Translational Medicine, vol. 12, no. 524, pp. 1-11.

Schmidt, J, Kajtár, B, Juhász, K, Péter, M, Járai, T, Burián, A, Kereskai, L, Gerlinger, I, Tornóczki, T, Balogh, G & Vígh, L 2020, ‘Lipid and protein tumor markers for head and neck squamous cell carcinoma identified by imaging mass spectrometry’, Oncotarget, vol. 11, no. 28, pp. 2702-2717.