Clinical Pathology Tumor Markers PDF

FIRST SEMESTER: CLINICAL PATHOLOGY MIDTERMS TUMOR MARKERS #05 DR. FLORANNE MARGARET VERGARA, FPSP...

FIRST SEMESTER: CLINICAL PATHOLOGY MIDTERMS TUMOR MARKERS #05 DR. FLORANNE MARGARET VERGARA, FPSP OCT - 20 - 2023 Blood levels are determined by: OUTLINE → Tumor proliferation Overview → Tumor volume A. Definition → Proteolytic activities in tumor cell I B. Types of Tumor markers → Release from necrotic cells C. Clinical applications Individual tumor markers B. TYPES OF TUMOR MARKERS A. α Fetoprotein B. β microglobulin Can be: C. Calcitonin → Tumor antigen D. CEA → Oncogenes E. Estrogen and progesterone receptors → Enzymes II F. Her2-Neu → Hormones G. HCG → Receptors H. PSA I. Neuron-specific enolase J. CA 15-3 K. CA 125 L. Other tumor markers III APA references IV Review Questions V Freedom wall Texts in blue are taken directly from the lecturer’s PPT I. OVERVIEW A. DEFINITION Tumor marker - Biological indicators of tumors Any substance that is: → Present in or produced by tumor itself → Produced by host in response to a tumor → Used to differentiate tumor from normal tissue → Detected in cell, tissue, or body fluids ▪ Quantitatively or qualitatively ▪ By chemical, immunological, or molecular methods → To Identify presence of cancer IDEALLY, these should be: → 100% sensitive and specific (usually not achieved) → Positively correlated with tumor volume and extent ▪ The larger the tumor, the higher levels of the marker → Elevated in serum at early cancer stage → Able to predict recurrence before cancer is clinically detectable → Easily measurable and reproducible Three categories: → Tumor associated proteins Table 1: Types of Tumor Markers (lifted from Dr. Vergara’s PPT) ▪ Also present in certain non-neoplastic conditions ▪ e.g. Oncofetal antigens Examples: → Oncoproteins → Oncofetal antigens ▪ e.g. Overexpressed; involved in regulation of cell ▪ Normally expressed in fetal development but not in cycle adults and children → Patterns of protein expression (recently discovered) ▪ e.g. α-fetoproteins and carcinoembryonic antigens ▪ Unique to specific types of cancer → Proteins in epithelial cells One or more cancer biomarkers may be present in serum ▪ Seen in adenosquamous and SCC of patients with cancer ▪ e.g. CA 19-9, CA 125, and CA 15-3 Should be related to any of the ff: → Polypeptide hormones elevated in specific tumors → Malignant transformation ▪ e.g. β-hCG, alkaline phosphatase → Proliferation → Hormone-like proteins ▪ e.g. HER2/neu and PSA ▪ e.g. PTH-like protein, causing hypercalcemia → Dedifferentiation (anaplasia) (paraneoplastic syndromes like in renal cell ▪ e.g. Carcinoembryonic antigen carcinomas) → Metastasis Serum markers are usually preferred than tissue-based because these are: → Non-invasive → More accurate → Lack of interobserver difference (TWG) DAUMAR, R. | (TEG) OSTAN, C; SOBRECAREY, R. | (TC) COSTALES, D. NMD2026  Lesson 5: TUMOR MARKERS NMD2026 → AFP from primary hepatocellular carcinomas have ONCOPROTEINS additional fucose compared with AFP from benign liver Directly or indirectly involved in mitosis; in signal disease transduction or in regulation of transcription Ectopic proteins HER2/neu - transmembrane EGF receptor w/ intracellular → e.g. Carcinoembryonic proteins tyrosine kinase ▪ Detected in fetal and tumor tissues but not in normal ○ signal is relayed by Grb-2 to SOS then SOS relays to adult tissues Ras-p21 ▪ Relies on immunoassays c-Myc - a transcription factor that induces synthesis of ▪ Can predict prognosis mitogenic proteins ▪ Not suitable for screening due to cross-reactivity with normal proteins and do not appear in blood at early TUMOR SUPPRESSORS/CELL DIFFERENTIATION stages of cancer → Much more reliable than hormones and metabolites Normally suppresses cell growth p53 - deletion/mutation predispose cells to malignant C. CLINICAL APPLICATIONS transformation (50% of malignancies) Clinical utility depends almost totally on specificity and → Detected by PCR-SSCP and DHPLC sensitivity of tumor marker → Abnormal p53 may be indicated by anti-p53 antibodies → Recall: ▪ Correlated with Ki-67 (marker for proliferation) and ▪ Sensitivity - how well a test can detect all patients ER expression, used in breast CA with a specific cancer (measures true positivity) BRCA1 - half of cases of inherited breast CA − Sn = true positive / (true positive + false negative) → Also in ovarian, colon, and prostate CA ▪ Specificity - how well a test can tell that a positive BRCA2 - 70% of inherited breast CA not caused by test is indeed the specific cancer (not benign or BRCA1 mutations others) (measures true negativity) → Assoc. w/ male breast CA − Sp = true negative / (true negative + false negative) ADHESION MOLECULES AND METASTASIS Tumor metastasis involves major steps: Note: In Doc Vergara’s PPT, she said that specificity → Penetration of tumor cells to vascular or lymphatic measures false positivity; however vessels Sensitivity - TRUE POSITIVE RATE → Carrying of tumor cells to distant sites and lodging to Specificity - TRUE NEGATIVE RATE capillary beds of distant organ → Penetration to the organ Tumor markers may be: Requires integrins, selectins, cadherins, and other cell → Present in non-malignant conditions (lower specificity) adhesion molecules → May not be present in associated cancers (lower → Late-stage breast CA and gastric CA - elevated ICAM, sensitivity) VCAM, and E-selectin Useful in monitoring ▪ Elevated VCAM - indicator of shorter survival → e.g. Elevated CEA in sera of colon cancer px that had → Decreased E-selectin and ICAM - denotes resection means tumor recurrence effectiveness of chemotherapy in Hodgkin disease Examples: → PSA MONOCLONAL ANTIBODY-DEFINED TUMOR ▪ For screening prostate cancer MARKERS ▪ Organ specific but not cancer specific (could also be Tumor markers can now be detected through hybridoma elevated in benign prostatic hyperplasia) technology → HER2/neu → Unlimited supply of monoclonal Abs (MAbs) ▪ Used for monitoring therapy and marker of prognosis → Recommended when available because of increased ▪ Cancer specific but not tissue specific (may be found sensitivity and specificity among other advantages in cancers not in breast) → Also recommended to use multiple MAbs CA 19-9, CA 15-3, and CA125 are antigens detected by SCREENING MAbs Testing for CA in people who have NO symptoms of → Much more reliable than CEA for pancreatic, ovarian, disease and breast CA testing Not recommended if: → Lack of desired sensitivity and specificity OTHER MARKERS ▪ Note: Most tumor makers are nonspecific; hence, Hormones and their metabolites (e.g. homovanellic acid causes unnecessary alarm and 5-hydroxyindoleacetic acid) may be elevated in − e.g. CA 125 can be also elevated in tumors endometriosis (benign) → May be higher when benign tumors transform to → Not elevated in early stages of cancer malignant PSA + Digital rectal exam → High false-positive rates → Most widely accepted screening method for prostate ▪ Except placental alkaline phosphatase or PLAP CA (elevated in germ cell tumors) found in serum and ▪ Inc. PSA w/ small prostate gland - Prostate CA CSF ▪ Inc. PSA w/ large prostate gland - BPH ▪ Inc. PLAP in CSF in px with pineal tumor - dx is α-fetoprotein + ultrasound scanning germ cell tumor → Screening for hepatocellular carcinoma in endemic Sugars and glycoproteins areas (e.g. China) → e.g. CA 19-9 ▪ Tumor markers arising from altered DIAGNOSIS glycosyltransferase activity Using tumor marker levels ALONE is insufficient for dx → Fails to distinguish malignant from benign 2 of 9  Lesson 5: TUMOR MARKERS NMD2026 → Not elevated in every person with cancer (early stages) ▪ ER-PR positive - have good prognosis → Many are not specific to a particular cancer; only ▪ HER2/neu and Ki-67 positive - poorer prognosis suggests ▪ e.g. MONITORING TREATMENT AND RECURRENCE − Inc. CA 125 - suggests ovarian cancer − Inc. CA 15-3 - suggests breast cancer Serum level of tumor markers reflect: Measurement of velocity and density of tumor markers → Success of surgery improve sensitivity and specificity → Efficacy of chemotherapy → Velocity - Rate of increase in PSA per time Dec. tumor marker blood level - almost always a sign of → Density - PSA divided by volume of prostate gland (via effective treatment transrectal ultrasound) Tumor marker blood level remains elevated may mean: ▪ Relate with example above on PSA + digital rectal → Incomplete removal of tumor exam → Recurrence Tumor markers are NOT a diagnostic tool → Presence of metastasis → An adjunct test to clinical findings and medical imaging Always get pre-operative levels of tumor marker for ▪ e.g. Cirrhosis + mass in liver + inc. α-fetoprotein = comparison hepatocellular carcinoma Recommendation: Use multiple markers to improve DETECTION OF RECURRENCE diagnostic yield Second most useful application of tumor marker Tumor marker testing can detect cancer recurrence even STAGING AND PROGNOSIS 3 to 6 months before appearance of clinical or radiological Detection of tumor markers for malignancy and evidence of recurrence metastases will suggest more rigorous and systemic Specificity is not a problem for this application treatment Pre-therapeutic levels of tumor markers contribute as prognostic factor due to linkage with: D. RECOMMENDATIONS FOR ORDERING TUMOR → Metabolic activity MARKERS → Tumor size → Invasion Allow doctors to adjust therapeutic strategy NEVER RELY ON THE RESULT OF A SINGLE TEST → For groups with risk of failure response to therapy Tumor markers are non-specific Proteins reflecting metastasis (e.g. proteases and → Difficult to differentiate between malignant and benign adhesion molecules) Most elevations of tumor markers: → Better markers for predicting prognosis → Non-malignant disease - often transient → However, these are still measured in tumor tissues (not → Malignant disease - persistently high and rise blood so invasive) continuously Correlating the levels of c-ERBB2 extracellular domain Order serial testing (ECD) with other serum tumor markers can be helpful → To detect falsely elevated levels in transient elevations Trastuzumab (an antibody used for treating HER2+ breast → To ensure that any change is due to change in tumor CA) and diagnostic monoclonal Abs bind to the ECD of volume or activity (not laboratory variability) c-ERBB2 (aka HER2/neu) but on different sites of the protein → Also, diagnostic MAbs only bind to ECD if it’s cleaved BE CERTAIN TO ORDER THE TESTS FROM SAME off from cell membrane by metalloproteinases LABORATORY → Therefore, trastuzumab does not interfere with Order from the same laboratory and make sure that the measurements of ERBB2 (refer to Figure 2). laboratory must use the same assay kit because different commercial kits yield different results TUMOR MARKER MUST BE ELEVATED BEFORE THE SURGERY Pre-operative levels are used as baseline Multiple markers should be measured before surgery Tumor marker with highest elevation is used for monitoring disease activity CONSIDER THE HALF-LIFE OF THE TUMOR MARKER IN INTERPRETATION OF RESULTS Estimate the time required for decline of tumor marker to normal levels Figure 2. Trastuzumab and MAbs on HER2/neu Tumor markers are not assessed in less than 2 weeks after operation Examples You can wait for one whole month before testing again → Pre-operative PSA levels Example: Half-life of PSA is 3 to 4 days ▪ High - assoc. w/ high gleason score + lymph node → It takes 30 days for PSA at 50 mg/dL to drop to status undetectable levels − Gleason scoring: For prostate cancer grading o Neoplastic cells that look similar to healthy cells have lower scores CONSIDER HOW TUMOR MARKER IS REMOVED OR ▪ Normal - px will respond better to therapy METABOLIZED → Breast tumor 3 of 9  Lesson 5: TUMOR MARKERS NMD2026 Serum tumor markers are usually elevated in px with renal or liver disease → e.g. CEA elevated in px with liver disease because of impaired clearance of CEA → e.g. β2-microglobulin is elevated in px with renal failure ▪ β2-microglobulin is small and can normally pass through glomerular membrane USE OF MULTIPLE MARKERS Improves both sensitivity and specificity of diagnosis Remember: tumors are made up of heterogeneous cell types → Some cells may express only a single marker while some produce multiple → Some markers are not unique to an individual cell → Some cells may never produce any unique marker This explains why a multitude of markers should be tested to improve the detection sensitivity Figure 3. Hook Effect Illustration However a unique pattern of multiple markers may be identified w/ tumors derived from the same tissues ECTOPIC TUMOR MARKERS → Ex. Colon -> CEA, CA 19-9, CA 15-3, CA125 The expression of tumor markers is under genetic → CA 15-3 and CA 72-4 with Ca 125 can increase the regulation specificity of CA125 to differentiate malignant from Ectopic Tumor markers results from loss of regulation of benign ovarian disease genetic expression → GI cancers -> CEA, CA19-9, and CA 72-4 Remember: Important: tumor markers must be COMPLEMENTARY to → Benign tumors are usually well-differentiated each other ▪ Often proteins produced by the tumor that are cell-specific and are related to normal cell products ORDER THE NON-SPECIFIC MARKERS FOR COST at an elevated concentration SAVING AND FOR THEIR HIGH SENSITIVITY → Malignant tumors tend to be poorly differentiated ▪ Synthesis of these cell-specific proteins may no This point is not seen in henry’s book but the writer believes longer occur in the malignant cells that doc included this as a practical point in our clinical ▪ However, proteins that are normally found at an early practice fetal stage and not in normal cells or in benign Inexpensive and simple to measure tumors of these cells may become constitutively Although lack specificity for diagnosis expressed in the malignant cells → Sensitive to any change in tumor activity ▪ This is the reason why carcinoembyonic proteins To monitor efficacy of treatment in patients with known and ectopic tumor markers are expressed in diagnosis malignant, advanced cancers Presence of these markers are associated with poor HOOK EFFECT prognosis or metastasis Drawback of the sandwich-type immunoassay method Tend to give a false low value when the tumor marker II. INDIVIDUAL TUMOR MARKERS concentration in the specimen rises above a certain Note: Usually in studying tumor markers, always associate it w/ a highly elevated concentration particular organ/system so that you could easily remember its Recommendation: usage. The writers may place anecdotes as to the most common → The TM assay should be repeated with a 10-fold clinical usage for each of the markers as this is also the commonly diluted specimen asked questions for the particular tumor markers → Retest sample with the diluted specimen ▪ If normal sample : 10x lower value A. α-FETOPROTEIN ▪ Hook effect - yield a higher value In clinical practice : most commonly for Hepatocellular → Example prior to testing carcinoma ▪ HCG 1 ng/mL (but you suspect that this is not usual Major fetal serum protein & major carcinoembryonic for the presentation of the disease) protein ▪ Dilute specimen 1:10 Resembles albumin in function and structure ▪ If result if 0.1 ng/mL (10x lower because of the Synthesized by: dilution) -> true result/ normal sample → Yolk sac ▪ If result is HIGHER than the expected dilution i.e. → Fetal hepatocytes considerably higher than 0.1 ng/mL -> probable hook → Fetal GI and Kidney (lesser extent) effect Found elevated in Hook effect is also known as PROZONE EFFECT → Hepatocellular carcinoma (HCC) → Yolk-sac derived germ cell tumors ▪ Most useful serum marker for the above 2 cancers Transiently elevated in: → Pregnancy → Benign liver disease If combined w/ ultrasound testing: increased sensitivity to detect HCC → increases sensitivity from 75% to around 100% AFP may also be used for prenatal screening of neural tube defects 4 of 9  Lesson 5: TUMOR MARKERS NMD2026 → If combined w/ free B-HCG and unconjugated estradiol: Analysis of serum hCG subunits is especially useful for for down syndrome detection managing patients w/ germ cell tumors Elevated in: B. β2-MICROGLOBULIN → Trophoblastic tumors Constant light chain of the human histocompatibility locus → Choriocarcinoma antigen express on the surface of most nucleated cells → Testicular tumors Elevated in both ▪ Non-seminoma : 60% → Solid tumors; and ▪ Seminoma : 10-30% → Lymphoproliferative diseases ▪ B cell CLL H. PROSTATE-SPECIFIC ANTIGEN ▪ Non-Hodgkin lymphoma Synthesized uniquely in the epithelial cells of the prostate ▪ Multiple myeloma gland Good marker for lymphocytic activity Most widely used tumor marker discovered thus far → Hence making it a good marker for B cell malignancies Remember this normal value as it may be asked again in CSF determination: useful for detecting metastases in other subjects : 0-4 ng/mL the CNS → Even in local practice, this range is usually followed and most kits and testing have the same reference C. CALCITONIN range Most useful marker for screening and management of In clinical practice : mainly for medullary thyroid cancers prostate CA → To remember: remember that it is the thyroid that Main drawback: cannot distinguish between BPH/non contains the C (parafollicular) cells w/c secretes your malignant lesions and prostate CA calcitonin Useful in monitoring the success of surgical prostatectomy Elevated in patients w/ increased bone turnover rate → Complete removal -> undetectable PSA level associated w/ skeletal metastasis → If after radical prostatectomy : constant elevated or Ectopically elevated in : continuously increasing levels → Bronchogenic CA ▪ Due to residual prostatic tissue or → Medullary CA of thyroid ▪ Incomplete resection of the gland D. CARCINOEMBYONIC ANTIGEN I. NEURON-SPECIFIC ENOLASE In clinical practice : Gastrointestinal cancers (particularly Relatively specific for small cell lung CA (SCLC) Colorectal cancer) Useful marker for monitoring treatment & predicting Once thought to be specific for these cancers but was relapse in patients w/ SCLC found to be elevated in others Other tumors: Neuroblastoma, Carcinoid, → Hence, it is highly non-specific Pheochromocytoma Main usage: follow patients during therapy and to detect recurrence after successful surgery Important: Prior to discussing the “CA” markers, tips for memorizing Mainly metabolized in the liver the three most commonly used tests: → May be increased in conditions resulting to liver CA 15-3: the number 3 is like the female breast -> breast CA damage CA 125 : the figure 5 looks like a pregnant woman -> ovarian CA May also be increased in patients undergoing radiation or CA 19-9 : flip the number 9 -> “P”ancreatic CA chemotherapy J. CA 15-3 E. ESTROGEN AND PROGESTERONE RECEPTORS Circulating breast cancer associated antigen In breast tumor cytosol Present in AdenoCA (breast, colon, ovary, pancreas) → Sample to be tested is not the serum but breast tissue More sensitive * specific marker for monitoring clinical Identify patients who are most likely to benefit from course of patients w/ metastatic breast CA endocrine therapy Also elevated in → 85% of ER-PR (+) patients will respond → Chronic hepatitis, cirrhosis, sarcoidosis, TB, SLE and in Positive ER-PR indicate: patients who smoke → Good prognosis → Longer disease -free interval K. CA 125 → Longer overall survival Expressed by more than 80% of non-mucinous epithelial ovarian carcinomas F. C-ERBB-2 (HER-2/NEU) ONCOPROTEIN → Serous, endometrioid & clear cell carcinoma of the Mainly used in Breast Cancers ovary Found elevated in the sera of patients w/ epithelial cell A negative result does not always rule out tumor cancers including breast cancers recurrence → In patients w/ breast CA, this marker is very important Not useful in distinguishing benign vs malignant pelvic as a prognostic and predictive marker mass Increased level of this marker prior to therapy indicates: Also use for follow up on uterine tumors and in → Increased tumor size endometriosis → Tumor grade; and Increased in: → Positive lymph nodes → Tumors of FT; Amplified in 25-30% of human breast CA and ovarian CA → Trophoblastic tumors; Associated w/ poor prognosis and with short survival and → Cirrhosis; and recurrence → Disorders of GI tract G. HUMAN CHORIONIC GONADOTROPIN (HCG) L. OTHER TUMOR MARKERS Produced and secreted by trophoblast cells of the CA 19-9 : Pancreatic CA placenta Serum Light chain termination Detected in women during pregnancy → Monoclonal gammopathies in IgG and IgA: multiple myeloma 5 of 9  Lesson 5: TUMOR MARKERS NMD2026 → Monoclonal IgM gammopathy : Waldenström’s Non seminomatous testicular cancer macroglobulinemia a. Human chorionic gonadotropin Chromoganin A : pheochromocytoma, medullary 11 b. Alpha feto protein carcinoma of the thyroid, SCLC c. Both d. Neither III. APA REFERENCES [VERGARA] (2023). TITLE [Powerpoint Slides]. College of Medicine, Davao # QUESTION Medical School Foundation, Inc. D. It should increase/ cause a higher value IV. REVIEW QUESTIONS 1 # QUESTION True regarding Hook effect, except a. Tumor marker concentration in the specimen rises Source: henry’s 23e, p916 above a certain highly elevated concentration A 1 b. Use the same sample when testing with a dilution c. Tend to give falsely low value d. 1:10 dilution will yield a lower value than the original 2 specimen Elevated in patient with increased bone turnover rate a. Calcitonin A. NSE =Neuron-Specific Enolase, Oat Cell Cancer 2 b. Chromogranin A aka Small Cell Cancer (check table 74-2 @ appendix) c. Carcinoembryonic antigen d. All of the above 3 Neuron-specific enolase is a useful marker for monitoring treatment and predicting relapse in patients with 3 a. Small cell lung carcinoma B b. Seminoma c. Pheochromocytoma d. Clear cell carcinoma of the ovary 4 Alpha-fetoprotein is synthesized by the following, except a. Yolk sac 4 b. Germ cells C c. Fetal kidney d. Fetal hepatocytes e. None of the choices 5 Markers for Multiple Myeloma, EXCEPT a. Bence Jones Proteins 5 b. IgA c. TdT 6 B d. Beta-2-M 7 A Alpha-fetoprotein is elevated in 8 C a. Ovarian CA 9 A b. Breast CA 10 A 6 c. Renal CA 11 A d. None of the choices e. All of the choices V. FREEDOM WALL The appearance of ectopic tumor markers is associated with? a. Poor prognosis 7 b. Excellent prognosis c. Good prognosis d. No change in prognosis The following is true, except a. A single molecule may express more than one epitope 8 b. Monoclonal Ab are more specific and sensitive than polyclonal Ab c.. Tumor markers may differentiate between benign, malignant, and non-malignant Positive ER-PR indicate a. Good prognosis 9 b. Poor prognosis c. Worse prognosis than with HER2 positive CA d. No change in prognosis Pancreatic tumor a. CA19-9 10 b. CA15-3 c. CA125 d. Chromogranin A 6 of 9 INDEX: APPENDIX 7 of 9 8 of 9 9 of 9