Tumor Markers of Malignancies Shih-Hao Tang / 唐世豪, M.D. Division of Hematology & Oncology Kaohsiung Municipal Siaogang Hospital
Abstract • Tumor markers, as one of the special categories of biomarkers, facilitate the detection and diagnosis of malignancies. • It may also provide information about the prognosis of disease and the response to specific treatments. • Traditionally, most tumor markers consist of proteins and biochemicals. With the advances of methodologies and understanding of cancer biology, plenty of genetic markers are now available and have been implemented in clinical practice. • Numerous novel biomarkers have been introduced, as PD-L1 expression, tumor mutation burden and microsatellite instability reflect the possibility of response to immunotherapy, there are also studies showed the promising roles of circulating tumor cells, epigenetic markers, and exosomes.
Outline • Definition of Tumor Markers • The Ideal Tumor Markers • Utilization • Prognostic versus predictive value of biomarkers • Most Useful Tumor Markers • Pitfalls • Emerging Biomarkers & New Applications
Definition of Tumor Markers
“Tumor markers are substances that are produced by cancer or by other cells of the body in response to cancer or certain benign (noncancerous) conditions. Most tumor markers are made by normal cells as well as by cancer cells; however, they are produced at much higher levels in cancerous conditions. These substances can be found in the blood, urine, stool, tumor tissue, or other tissues or bodily fluids of some patients with cancer. Most tumor markers are proteins. However, more recently, patterns of gene expression and changes to DNA have also begun to be used as tumor markers.�
Definition of Tumor Markers
“Tumour biomarkers is a term used to describe many different potential markers of cancer development and progression. These markers can come in many forms – for example, proteins, biochemicals, DNA and RNA – and ideally they should be specific to a particular type of cancer and not present in normal tissues or in healthy individuals.”
Definition of Tumor Markers
“Tumor markers are substances found at higher than normal levels in the blood, urine, or body tissue of some people with cancer. Although cancer cells often produce tumor markers, healthy cells in the body may produce them as well. Tumor markers are also called biomarkers.�
The Ideal Tumor Markers • High positive and negative predictive value • Inexpensive, simple, standardized and automated assay, with clearly defined reference limits • Reproducible / Validation • Acceptable to subjects • Multiplex
Characteristics of Tumor Markers • Source • Tumor cells, normal cells
• Components • Protein, RNA, DNA, biochemicals • Gene expression, DNA alteration
• Existence • Blood, urine, stool, tumor tissue, or other tissues or bodily fluids
• Clinical Usage • Reflect tumor development, progression, and…
Tumor Markers Prognostic vs Predictive Biomarkers • Prognostic biomarker • Provides information about the patients overall cancer outcome, regardless of therapy
• Predictive biomarker • Provides information about the effect of a therapeutic intervention • Can also be a target for therapy (e.g. ER, PR, HER2/neu, BCR-ABL, EGFR…)
Utilization SCREENING
PROGNOSIS
SURVEILLANCE
DIAGNOSIS
PREDICTION
Prognostic vs Predictive
Some of The Most Useful Tumor Markers • Prostate-specific antigen (PSA)
• Human chorionic gonadotropin (HCG)
• CA 125
• CA 19-9
• Carcinoembryonic antigen (CEA)
• CA 15-3
• Alpha-fetoprotein (AFP)
• Lactate dehydrogenase (LDH)
• CA 27-29
Prostate-Specific Antigen (PSA)
Prostate-Specific Antigen (PSA) Source proPSA (secretory cells within prostate)
(in lumen) (diffuse) Active PSA
PSA Circulation
(proteolysis)
Inactive PSA
free PSA
Prostate-Specific Antigen (PSA) Source proPSA (secretory cells within prostate)
Prostate cancer: • Lack of basal cells • Disrupt the basement membrane and normal lumen structure
(in lumen) (leak) Active PSA
Increase
PSA free PSA
(escape proteolysis)
Relatively decreased Inactive PSA
(leak)
Circulation
Prostate-Specific Antigen (PSA) • Studies in the 1980s confirmed that serum total PSA could be used as a screening tool to identify men with prostate cancer because elevated serum PSA is clearly a more sensitive marker than digital rectal examination • Prostate-specific antigen (PSA) is always present in low concentrations in the blood of adult males • Normal ranges • Normal < 4 ng/ml (half life 2-3 days)
• Half-life: about 3 days in circulation
Prostate-Specific Antigen (PSA) Causes of Elevation • Benign prostatic hyperplasia (BPH) • Prostate cancer • Prostatic inflammation / infection • Perineal trauma
Prostate-Specific Antigen (PSA)
Roobol MJ, Carlsson SV. Nat Rev Urol 2013;10:38-48.
Prostate-Specific Antigen (PSA) >4 ng/mL More likely to have metastatic disease
Poorer prognosis
Roobol MJ, Carlsson SV. Nat Rev Urol 2013;10:38-48.
Prostate-Specific Antigen (PSA) Age-Specific PSA Reference Ranges
Liu ZY, et al. Asian J Androl 2009;11:100-3.
Prostate-Specific Antigen (PSA)
Roobol MJ, Carlsson SV. Nat Rev Urol 2013;10:38-48.
Prostate-Specific Antigen (PSA) Pitfalls • 20 and 50% of men with newly diagnosed prostate cancers in the United States have serum PSA values below 4.0 ng/mL • Prostatitis with or without infection • Free PSA less affected by inflammation • But some studies indicated that free-to-total ratio of serum PSA is unable to distinguish chronic inflammation from prostate cancer
• Prostate massage and digital rectal examination may cause minor transient elevations, but without clinical significance • Mechanical manipulations: cystoscopy, biopsy, bicycle riding • Presence of heterophile antibodies • Affects many tumor markers detection
Heterophile Antibodies
Alpha-fetoprotein (AFP)
Alpha-fetoprotein (AFP) • A protein encoded in humans by the AFP gene • A major plasma protein produced by the yolk sac and the liver during fetal development and is considered as the fetal form of albumin • Normal ranges: <10-15 ng/mL • Half-life: 5-7 days • Normalization of the serum AFP concentration over 25-30 days after successful treatment
Alpha-fetoprotein (AFP) • Alpha-fetoprotein (AFP) is normally elevated in pregnant women since it is produced by the fetus • AFP is not usually found in the blood of adults • In men, and in women who are not pregnant, an elevated level of AFP may indicate liver cancer or cancer of the ovary or testicle • Noncancerous conditions may also cause elevated AFP levels • Ataxia telangiectasia, infant developmental birth defects
Alpha-fetoprotein (AFP) Causes of Elevation • Most common • Liver cancer • Ovarian cancer • Germ cell tumor of the testicles
• Occasionally • Stomach, colon, lung, breast, and lymphoma • Cirrhosis, hepatitis • Heterophilic antibodies
• Serum AFP concentrations above 10,000 ng/mL • Nonseminomatous germ cell tumors (NSGCTs) • Hepatocellular carcinoma (HCC)
Alpha-fetoprotein (AFP) In Germ Cell Tumors • Frequency of elevation correlates to NSGCTs stage • Stage I: 10-20% • Metastatic: 40-60% • Similar in β-HCG
• Pure seminomas • AFP may slightly elevated, around 10.4 to 16 ng/mL • If higher, consider nonseminomatous component of the tumor or with liver metastases
Alpha-fetoprotein (AFP) In Hepatocellular Carcinoma • Serum levels of AFP do not correlate well with other clinical features of HCC, such as size, stage, or prognosis • Serum levels greater than 400-500 ng/mL in highrisk patient is diagnostic of HCC • But, HCC is often diagnosed at a lower AFP level • Up to 40% patients with small HCC have AFP within normal limits • HCC due to alcoholism has less frequency of AFP elevation comparing with those caused by virus
Alpha-fetoprotein (AFP) In Hepatocellular Carcinoma • Fibrolamellar carcinoma (variant of HCC) • Normal AFP level
• With cutoff value greater than 20 ng/mL • Sensitivity: 41-65% • Specificity: 80-94% • Low positive predictive values; not a good screening test for HCC
CA 125
CA 125 / MUC16 Source • CA 125 is a glycoprotein encoded by MUC16 gene • Normal ranges • 0-35 units/mL (0-35 kU/L)
CA 125 / MUC16 Causes of Elevation • Malignant conditions • Epithelial ovarian carcinoma (including fallopian tube and primary serous peritoneal carcinoma) • Endometrial carcinoma • Endocervical adenocarcinoma • Pancreatic carcinoma • Breast carcinoma • Lymphoma • Lung carcinoma • Colorectal carcinoma • Squamous cervical/vaginal carcinoma
CA 125 / MUC16 Causes of Elevation • Benign conditions • • • • • • • • • • • • •
Endometriosis Cirrhosis Acute peritonitis Acute pancreatitis Acute pelvic inflammatory disease First trimester of pregnancy Abdominal surgery Chronic obstructive pulmonary disease Severe heart failure Active tuberculosis Lupus erythematous Meigs’ syndrome Non-disease state
CA 125 / MUC16 Causes of Elevation
Meigs’ syndrome • Triad of ascites, (right) hydrothorax, and benign ovarian tumor (ovarian fibroma, fibrothecoma, Brenner tumor, and occasionally granulosa cell tumor) • Rule out other malignant diseases, e.g. ovarian cancer • Treatment: surgical resection (↓CA 125)
CA 125 / MUC16 • CA 125 is mainly used to monitor the treatment response and recurrence of ovarian cancer • Pretreatment serum CA-125 concentration appears to have prognostic value in patients with fallopian tube cancer • Limited specificity
Carcinoembryonic Antigen (CEA)
Carcinoembryonic Antigen (CEA) • A glycosylphosphatidylinositol cell surface anchored glycoprotein • May correlate to the metastatic dissemination of colon carcinoma cells • Carcinoembryonic antigen (CEA) is normally found in very small amounts in the blood • Normal ranges • Non-smoker <2.5 ng/mL • Smoker <5.0 ng/mL
Carcinoembryonic Antigen (CEA) Causes of Elevation • Malignant conditions • • • • • • • • •
Colorectal carcinoma Gastric carcinoma Cholangiocarcinoma Pancreatic carcinoma Lung carcinoma Breast carcinoma Medullary thyroid carcinoma Ovarian cancer Urinary tract cancer / Prostate cancer
Carcinoembryonic Antigen (CEA) Causes of Elevation • Benign conditions • • • • • • • •
Smoking Gastritis, peptic ulcer disease, diverticulitis Liver disease: cirrhosis, fulminant hepatitis Chronic obstructive pulmonary disease Diabetes Renal failure, hemodialysis Hypothyroidism Any acute or chronic inflammatory state
• Adjuvant therapy (alter liver function)
Carcinoembryonic Antigen (CEA) In Colorectal Carcinoma (CRC) • Not for screening or diagnosing • Elevated CEA levels should return to normal after successful surgical resection or within 6 weeks of starting treatment if cancer treatment is successful • Because it lacks both sensitivity and specificity, serum • For established CRC, the absolute level of the serum CEA correlates with disease burden and is of prognostic value
Carcinoembryonic Antigen (CEA) In Colorectal Carcinoma (CRC) â&#x20AC;˘ Serial measurement of CEA can detect disease recurrence even among patients with an initially normal CEA level, although the sensitivity is lower (27-50%)
CA 19-9
CA 19-9 • Also named as cancer antigen 19-9 or sialylated Lewis (a) antigen • Primarily used for pancreatic cancer • Screening (but discouraged by ASCO guideline) • May be useful in distinguishing between cancer and other pathology of the gland • The value closely related to the tumor size
CA 19-9 Causes of Elevation • Malignant conditions • • • •
Pancreatic cancer Colorectal cancer Esophageal cancer Hepatocellular carcinoma
• Benign conditions • • • •
Pancreatitis Cirrhosis Diseases of the bile ducts Heterophilic antibodies
Human Chorionic Gonadotropin (hCG)
Human Chorionic Gonadotropin (hCG) • Synthesized in large amounts by placental trophoblastic tissue and in much smaller amounts by the hypophysis and other organs such as testicles, liver, and colon • hCG exists in many forms in serum, including intact molecule, β-hCG, and hyperglycated forms, and other forms including C-terminal peptide
Human Chorionic Gonadotropin (hCG) • If pregnancy is ruled out, hCG may indicate cancer in the testis, ovary, liver, stomach, pancreas, and lung • Marijuana use can also raise hCG levels • Clinical tests for pregnancy • Total hCG levels ≧20 mIU/mL
Human Chorionic Gonadotropin Causes of Elevation • Ovarian or testicular cancer / Germ cell tumor • Pregnancy • Human antibodies against animal antibodies (HAAA) • Heterophilic antibody
Other Commonly Used Markers
CA 15-3 • The CA 15-3 marker is most useful in evaluating the effect of treatment for women with advanced breast cancer. • Elevated levels of CA 15-3 are also associated with cancers of the ovary, lung, and prostate, as well as noncancerous conditions such as benign breast or ovarian disease, endometriosis, pelvic inflammatory disease, and hepatitis. • Pregnancy and lactation also can raise CA 15-3 levels.
Lactate dehydrogenase (LDH) • Lactate dehydrogenase (LDH) LDH is a protein that normally appears throughout the body in small amounts. • Many cancers can raise LDH levels, so it is not useful in identifying a specific kind of cancer. • Measuring LDH levels can be helpful in monitoring treatment for cancer. • Noncancerous conditions that can raise LDH levels include heart failure, hypothyroidism, anemia, and lung or liver disease.
Squamous Cell Carcinoma Antigen (SCC) • A subfraction of tumor-antigen (TA-4) antigen • Originally isolated from women with squamous cell carcinoma of the cervix • Serum antigen levels were positive in 53.5% of cervical squamous cell carcinoma • the changes in serum antigen levels reflected the disease progress.
• Serum SCC antigen is elevated in squamous cell carcinomas of several sites, including esophagus, lungs, vagina and head and neck
CYFRA 21-1 • Fragment of cytokeratin 19 (CK19) • Benign lung disease: pneumonia, sarcoidosis, tuberculosis, emphysema, chronic bronchitis… • Malignancy: Non-small cell lung cancer (especially SCC), esophagus cancer • breast cancer, bladder cancer, head and neck cancer
EBV-IgA â&#x20AC;˘ EBV is a primary etiologic agent in the pathogenesis of nasopharyngeal carcinoma (NPC) â&#x20AC;˘ Patients with NPC demonstrate specific serologic responses to various gene products of EBV, particularly immunoglobulin A (IgA) antibodies directed against the EBV viral capsid antigen (VCA/IgA)
Estrogen Receptor (ER) • Estrogen is associated with numerous diseases • cancers, osteoporosis, neurodegenerative diseases, cardiovascular disease, insulin resistance, lupus erythematosus, endometriosis, and obesity.
• Estrogen and the ERs have also been implicated in breast cancer, ovarian cancer, colon cancer, prostate cancer, and endometrial cancer. • Estrogen receptors are over-expressed in around 70% of breast cancer cases • Prognostic factors for invasive breast cancer
• Selective estrogen receptor modulators (SERMs): tamoxifen, raloxifene
Progesterone Receptor (PR) • Progesterone mediates mammary gland stem cell selfrenewal. • PRs function not only as critical regulators of transcription but also to activate signal transduction pathways, many of which are involved in pro-proliferative signaling in the breast. • In the mammary gland, PR expression is restricted to the luminal epithelial cell compartment. • ER is critical for ductal morphogenesis, whereas PR has a key role in lobuloalveolar differentiation.
• Lifetime exposure to steroid hormones (either exogenous or endogenous) is a critical risk factor for the development of breast cancer.
Human Epidermal Growth Factor Receptor 2 (HER2) • The HER2 receptor belongs to the epidermal growth factor receptor (EGFR) family of receptors • Amplification or overexpression of the HER2 oncogene is present in approximately 15~30% of primary breast cancers • HER2 status is a predictive factor in breast cancer • HER2 overexpression was associated with high rates of disease recurrence and death
• Anti-HER2 monoclonal antibody: Trastuzumab (Herceptin®)
Epidermal Growth Factor Receptor (EGFR) • ErbB family: EGFR (ErbB-1), HER2/neu (ErbB2), Her 3(ErbB-3) and Her 4 (ErbB-4). • Associated with cell proliferation, migration, metastasis, resistance to apoptosis and angiogenesis. • Mutated EGFR in many malignancy: Lung cancer, colorectal cancer, glioblastoma, head and neck cancer…
RAS Proto-oncogene • RAS gene is associated with cell growth, differentiation and survival. • The 3 RAS genes in humans (HRas, KRas, and NRas) are the most common oncogenes in human cancer • NRAS (neuroblastoma RAS viral (v-ras) oncogene homolog) • HRAS (Harvey rat sarcoma viral oncogene homolog) • KRAS (Kirsten rat sarcoma viral oncogene homolog)
• Mutations in the Ras family of proto-oncogenes are very common, being found in 20% to 30% of all human tumors. • Adenocarcinomas of the pancreas (90%) and colon (30%), lung cancer (30%), thyroid cancer (50%), bladder cancer, ovarian cancer, myeloid leukemia…
Factors Affecting Sensitivity and Specificity • Sample size (e.g. serum vs tissue) • Stability of sample / Processing time • Proper use of negative controls • Background profiling
Pitfalls of Commonly Used Tumor Markers
Emerging Biomarkers • Programmed death-ligand 1 (PD-L1), tumor mutation burden (TMB), and microsatellite instability (MSI) • Circulating tumor cells • Epigenetics • Exosomes
THANK YOU FOR YOUR ATTENTION