Tumour Markers Dr. Bani Flashcards
(114 cards)
1
Q
What is a tumor?
A
An abnormal growth of cells that serves no purpose.
2
Q
What distinguishes a malignant tumor from a benign tumor?
A
Malignant tumors can invade nearby tissue and spread to other parts of the body, while benign tumors do not.
3
Q
How many different diseases does cancer encompass?
A
> 200 different diseases.
4
Q
What are tumor markers?
A
Biochemical substances elaborated by tumor cells due to the malignant process.
5
Q
What can tumor markers indicate?
A
The presence of cancer when present in significant amounts.
6
Q
List the types of substances that can be tumor markers.
A
- Proteins
- Antigens
- Enzymes
- Metabolites
- Oncogene products
7
Q
What are oncofetal antigens? Give examples.
A
Tumor markers such as alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA).
8
Q
What is the significance of an ideal tumor marker?
A
It should be absent or present at low levels in non-diseased individuals and provide no false positives or negatives.
9
Q
What are the criteria for an ideal tumor marker?
A
- High positive and negative predictive value
- 100% accuracy in differentiating between healthy individuals and tumor patients
- Predicts early recurrence
- Clinically sensitive
10
Q
What factors affect the diagnostic efficiency of tumor markers?
A
- Sensitivity
- Specificity
- Positive predictive value (PPV)
- Negative predictive value (NPV)
11
Q
What does the sensitivity of a tumor marker indicate?
A
The probability that the test results will be positive if a tumor is present.
12
Q
What is the negative predictive value (NPV) of a tumor marker?
A
The probability that the disease is not actually present if the test result is negative.
13
Q
True or False: Most tumor markers are suitable for general screening.
A
False.
14
Q
How can tumor markers help in determining recurrence?
A
If a marker is elevated before treatment and rises after treatment, it likely indicates cancer recurrence.
15
Q
What role do enzymes play in tumor markers?
A
Plasma enzyme activities often increase due to secondary effects of tumors.
16
Q
What is lactate dehydrogenase (LDH)?
A
An enzyme involved in energy production, elevated in many large tumors.
17
Q
What is neuron-specific enolase (NSE) and its significance?
A
An enzyme elevated in certain tumors like small cell lung cancer, used for prognosis and monitoring.
18
Q
What is the clinical use of prostatic acid phosphatase (ACP)?
A
Confirmation and staging of metastatic prostate cancer.
19
Q
What is the reference range for total acid phosphatase in adult plasma?
A
0.5-5.5 U/L.
20
Q
What does elevated plasma ACP levels indicate in prostatic carcinoma?
A
Presence and extent of invasive or metastatic prostatic carcinoma.
21
Q
Fill in the blank: An ideal tumor marker should correlate with _______.
A
[tumor mass and stage]
22
Q
What is the significance of iso-enzyme measurement in tumor markers?
A
It can improve specificity in diagnosing tumor types.
23
Q
List some examples of useful enzymes in malignancy.
A
- Alkaline phosphatase
- Lactate dehydrogenase (LDH)
- Creatine kinase
- Neuron-specific enolase (NSE)
24
Q
What is the role of tumor markers in cancer prognosis?
A
Some markers help determine how aggressive a cancer is likely to be.
25
What happens to plasma ACP levels in metastasized prostatic carcinoma?
Plasma ACP levels rise due to an increase in the number of prostatic cells
## Footnote
Osteoblastic metastasis results in a rise in plasma ACP to about 9 U/l, and in severe metastasis, levels above 200 U/l may be attained.
26
What is the plasma TLACP activity in carcinoma still confined within the capsule of the prostate?
It does not rise above the upper limit of the reference values.
27
What does a dramatic fall in TLACP indicate in a patient with prostatic carcinoma on oestrogen therapy?
Response to treatment.
28
What indicates treatment failure in prostatic carcinoma?
Any subsequent increase in TLACP after a fall.
29
Can increased plasma TLACP activity be considered a reliable indication of prostatic carcinoma?
No, it can occasionally be increased in benign prostatic hyperplasia.
30
In what percentage of cases with metastasizing prostatic carcinoma are marked elevations of TLACP observed?
75% or more.
31
What precaution should be taken during ACP determination regarding rectal examinations?
ACP determination should NOT be done on patients who have undergone rectal examination within 48 hours.
32
What can cause the release of prostatic ACP into circulation?
Straining at stool and rectal examination.
33
How is prostate acid phosphatase (PAP) activity in prostate tissue compared to other tissues?
200 times more abundant.
34
What is the main clinical use of PAP?
Staging apparently localized disease prior to definitive therapy.
35
What has reduced interest in PAP assays for prostatic cancer?
The availability of the more sensitive and specific PSA assay.
36
What is PSA also known as?
Gammaseminoprotein.
37
What family does PSA belong to?
Glandular kallikrein family.
38
What role does PSA play in seminal fluid?
It cleaves seminogelin, liquefying seminal coagulum to release spermatozoa.
39
What prevents PSA from escaping into circulation?
The basement membrane.
40
What is the major immunoreactive form of PSA in serum?
PSA-ACT (Prostate Specific Antigen - a1 Antichymotrypsin) complex.
41
What percentage of total PSA in serum does PSA-ACT constitute?
80-90%.
42
What is the significance of the remaining free PSA in serum?
It constitutes approximately 5-15% of total immunoreactive forms.
43
What has PSA emerged as in clinical practice?
The most useful and clinically relevant tumor marker for prostate carcinoma.
44
What percentage of prostate cancer diagnoses can be made by histology alone?
67%.
45
What is the range of serum PSA values considered normal?
< 4 µg/L.
46
What is the 'grey zone' for serum PSA values?
4–10 µg/L.
47
What is the PSA level indicative of prostate cancer?
> 10 µg/L.
48
What is the specificity and sensitivity of free PSA for prostate cancer?
97% specificity, 96% sensitivity.
49
What is the clinical significance of free PSA?
Lower percent-free PSA increases the chance of having prostate cancer.
50
What are some benign conditions that can elevate PSA levels?
* Benign prostatic hyperplasia (BPH)
* Prostatitis
* Urinary tract infection
* Sexual intercourse.
51
What are the four classes of genes implicated in cancer development?
* Protooncogenes
* Tumor suppressor genes
* Apoptosis-related genes
* DNA repair genes.
52
What tumor marker is associated with colon cancer and mutations?
KRAS.
53
What are BRCA1 and BRCA2 associated with?
Increased risk of breast, ovarian, prostate, pancreatic, and melanoma cancers.
54
What is SCC used for in clinical practice?
Detecting carcinoma of the cervix, lung, esophagus, and ENT region.
55
What are homovanillic acid and vanillylmandelic acid associated with?
Elevated concentrations in patients with neuroblastoma and pheochromocytoma.
56
What is the biological half-life of SCC?
20 minutes.
57
What are HOMOVANILLIC ACID and VANILLYLMANDELIC ACID?
Acidic metabolites of catecholamines excreted in elevated concentrations by patients with neuroblastoma and pheochromocytoma.
58
What does the S100B marker indicate?
A protein from neural tissue used for monitoring patients with malignant melanoma.
59
What is CA 549?
A mucin marker associated with breast cancer.
60
What does MCA stand for?
Mucin-like cancer associated antigen related to metastatic breast cancer.
61
What is the significance of Human chorionic gonadotropin (HCG)?
A marker of first choice for gonadal and extragonadal choriocarcinoma, showing 100% sensitivity for choriocarcinoma.
62
How does HCG correlate with testicular tumors?
Detection of HCG and AFP correlates with histological findings and is crucial for therapeutic procedures.
63
What is the peak concentration period of HCG during pregnancy?
Between the 10th and 12th weeks of gestation.
64
What are the reference values for HCG in healthy men and non-pregnant women?
Less than 5 IU/ml; post-menopausal women less than 10 IU/ml.
65
What does an elevated level of HCG indicate?
Poor prognosis and should be assayed frequently during therapy.
66
What is the role of calcitonin in cancer diagnosis?
Produced by C-cells of the thyroid, it serves as a marker for medullary carcinoma of the thyroid.
67
What cancers show increased calcitonin levels?
Medullary carcinoma of the thyroid, bronchogenic carcinoma, small cell lung cancer, breast, liver, lung, renal cancers, and carcinoid tumors.
68
What is the significance of catecholamines in pheochromocytoma?
Plasma and urinary norepinephrine and epinephrine levels are markedly increased.
69
What is Parathyroid hormone-related peptide (PTH-RP)?
Elevated in many cancers causing hypercalcemia, aiding in differential diagnosis.
70
What is the function of estrogen and progesterone receptors in breast tumors?
Help identify patients likely to benefit from endocrine therapy.
71
What is the clinical utility of Beta-2 microglobulin (2M)?
Used as a marker for B-cell leukemia, lymphomas, and multiple myeloma, but also elevated in solid tumors.
72
What is the relevance of serum ferritin in cancer patients?
Increased levels are reported in cancer patients even in the absence of iron overload.
73
What is Alpha-fetoprotein (AFP) and its clinical significance?
A glycoprotein marker useful in diagnosing and monitoring hepatocellular carcinoma and germ cell tumors.
74
What does carcinoembryonic antigen (CEA) signify?
Useful in the follow-up management of patients with various cancers, particularly colorectal cancer.
75
What are the limitations of CEA testing?
Not recommended as a general screening procedure but useful for prognosis and management in cancer patients.
76
What is the significance of elevated CEA levels?
Indicates various cancers but may also be elevated in benign conditions.
77
What is Carcinoembryonic antigen (CEA) and when may it be elevated?
CEA may be elevated in benign conditions like:
* cirrhosis
* pulmonary emphysema
* rectal polyps/cancer
* benign breast disease
* ulcerative colitis
## Footnote
Not sensitive for screening; useful in clinical staging, prognosticating, and monitoring therapeutic response.
78
What are high molecular weight mucins and their significance?
High molecular weight mucins are blood group antigens found on tumor cell surfaces or secreted by tumor cells. They are useful as tumor markers and are more specific than naturally secreted markers like enzymes and hormones.
79
Define tumor associated antigens.
Tumor associated antigens are defined by highly specific monoclonal antibodies produced against tumor tissue or cell lines of histologically well-defined primary tumors.
80
What is CA 125 and its association with cancer?
CA 125 is a tumor associated glycoprotein of more than 200KD, associated with epithelial ovarian carcinoma, and detected using murine monoclonal antibody OC125.
81
What role do keratins play in cancer diagnosis?
Keratins are marker proteins useful in diagnosing tumors of epithelial origin. They help distinguish epithelial from nonepithelial tumors.
82
What are oncogenes?
Oncogenes are derived from proto-oncogenes and are activated by gain-of-function mutations, encoding proteins that activate cell proliferation.
83
What is the function of tumor suppressor genes?
Tumor suppressor genes normally suppress cell division and promote apoptosis. Loss of normal function may lead to malignancy.
84
List some cancer types associated with ALK gene rearrangements.
Cancer types include:
* Non-small cell lung cancer
* Anaplastic large cell lymphoma
* Histiocytoses
85
What is Alpha-fetoprotein (AFP) associated with?
AFP is associated with liver cancer and germ cell tumors.
86
What cancer type is associated with B-cell immunoglobulin gene rearrangement?
B-cell lymphoma.
87
What is the significance of the BCL2 gene rearrangement?
BCL2 gene rearrangement is associated with lymphomas and leukemias.
88
What cancers are associated with Beta-2-microglobulin (B2M)?
Cancer types include:
* Multiple myeloma
* Chronic lymphocytic leukemia
* Some lymphomas
89
What is the role of Beta-human chorionic gonadotropin (Beta-hCG)?
Beta-hCG is associated with choriocarcinoma and germ cell tumors.
90
What does Bladder Tumor Antigen (BTA) indicate?
BTA is associated with bladder cancer and cancer of the kidney or ureter.
91
What cancer types are linked to BRCA1 and BRCA2 gene mutations?
Ovarian and breast cancers.
92
What is the Philadelphia chromosome associated with?
BCR-ABL fusion gene associated with chronic myeloid leukemia, acute lymphoblastic leukemia, and acute myelogenous leukemia.
93
What cancers is BRAF V600 mutation linked to?
Cancer types include:
* Cutaneous melanoma
* Erdheim-Chester disease
* Langerhans cell histiocytosis
* Colorectal cancer
* Non-small cell lung cancer
94
What does CA19-9 indicate?
CA19-9 is associated with pancreatic, gallbladder, bile duct, and gastric cancers.
95
What is the significance of CA 27.29?
CA 27.29 is associated with breast cancer.
96
What cancer type is indicated by Calcitonin?
Medullary thyroid cancer.
97
What is the role of CD19 in cancer?
CD19 is associated with B-cell lymphomas and leukemias.
98
What types of cancer is CD30 associated with?
CD30 is associated with classic Hodgkin lymphoma, B-cell and T-cell lymphomas.
99
What is Chromogranin A (CgA) associated with?
CgA is associated with neuroendocrine tumors.
100
What does microsatellite instability (MSI) indicate?
MSI is associated with colorectal cancer and other solid tumors.
101
What is the purpose of the 5-Protein signature (OVA1)?
Used to pre-operatively assess pelvic mass for suspected ovarian cancer.
102
What is the function of Prostate-specific antigen (PSA)?
PSA is used to help in diagnosis, assess response to treatment, and look for recurrence in prostate cancer.
103
What is the significance of UGT1A1*28 variant homozygosity?
It's used to predict toxicity from irinotecan therapy in colorectal cancer.
104
What does the presence of circulating tumor cells indicate?
Circulating tumor cells of epithelial origin are used to monitor metastatic breast, prostate, and colorectal cancers.
105
What is analyzed to help determine treatment in non-small cell lung cancer?
EGFR gene mutation.
106
What is the role of IDH1 and IDH2 gene mutations?
Associated with acute myeloid leukemia and help determine treatment.
107
What cancers are linked to Lactate dehydrogenase?
Cancer types include:
* Germ cell tumors
* Lymphoma
* Leukemia
* Melanoma
* Neuroblastoma
108
What is the purpose of the FoundationOne CDx (F1CDx) genomic test?
Used as a companion diagnostic test to determine treatment for any solid tumor.
109
What does the 21-Gene signature (Oncotype DX) evaluate?
It evaluates the risk of distant recurrence in breast cancer.
110
What is analyzed in the assessment of suspected ovarian cancer?
Blood
## Footnote
Blood tests are used to pre-operatively assess pelvic masses that may indicate ovarian cancer.
111
How is the 17-Gene signature (Oncotype DX GPS test) used in prostate cancer?
To predict the aggressiveness of prostate cancer and to help manage treatment
## Footnote
This test analyzes tumor samples to provide insights into the cancer's behavior.
112
What is the purpose of the 21-Gene signature (Oncotype DX) in breast cancer?
To evaluate risk of distant recurrence and to help plan treatment
## Footnote
This test analyzes tumor characteristics to inform treatment strategies.
113
What cancer type is analyzed using the 46-Gene signature (Prolaris)?
Prostate cancer
## Footnote
The Prolaris test assesses tumor samples to predict the aggressiveness of prostate cancer.
114
How is the 70-Gene signature (Mammaprint) used in breast cancer?
To evaluate risk of recurrence
## Footnote
This test provides information that can influence treatment decisions for breast cancer patients.
