Week 8

Question 1

Background concept of cancer

Answer 1

Cancer is inappropriate cellular proliferation.

Cancer is an abnormal state in which
uncontrolled proliferation of one or more cell
populations interferes with normal biological
functioning

Transformed cells generally display several or all
of the following properties:
spherical morphology
expression of fetal antigens, growth-factor
independence
lack of contact inhibition, anchorage-
independence
growth to high density.

Cancer can invade the body to different
degrees.
In the early stages, the abnormally proliferating
cells are usually restricted to the area in which the
cancer originated.
Progressive changes in the cancer cells may allow
them to escape from the primary site (metastasis),
and cause damage to the body on a larger scale.

Question 2

Cancer

Answer 2

Cancer is one of the most common diseases
in the developed world:
1 in 4 deaths are due to cancer
1 in 17 deaths are due to lung cancer
Lung cancer is the most common cancer in
men
Breast cancer is the most common cancer in
women
There are over 100 different forms of cancer

Question 3

What causes cancer?

Answer 3

Cancer arises from the mutation of a normal
gene.
Mutated genes that cause cancer are called
oncogenes.

A factor which brings about a mutation is called
a mutagen.
A mutagen is mutagenic.
Any agent that causes cancer is called a
carcinogen and is described as carcinogenic.
So some mutagens are carcinogenic.

Question 4

Benign or malignant?

Answer 4

Benign tumours do not spread
from their site of origin, but can
crowd out (squash) surrounding
cells eg brain tumour, warts.
Malignant tumours can spread
from the original site and cause
secondary tumours. This is called
metastasis. They interfere with
neighbouring cells and can block
blood vessels, the gut, glands,
lungs etc.

Question 5

Metastasis

Answer 5

To form a secondary
tumour, a tumour cell
needs to leave the vessel
system and invade
tissue. The cell must
attach itself to a vessel’s
wall.
Once this is done, it can
work its way through the
vessel and enter the
tissue.

Question 6

SUMMARY for cancer cells

Answer 6

Cancer Cells
1. Mutations occur in the
DNA when it is replicated.
2. Chemical signals that
start and stop the cell
cycle are ignored.
3. Cells do not
communicate with each
other and tumours form.

Question 7

Tumour Marker Definition

Answer 7

A tumour marker is anything present in or produced by
cancer cells or other cells of the body in response to cancer
or certain benign (noncancerous) conditions that provides
information about a cancer, such as how aggressive it is,
whether it can be treated with a targeted therapy, or
whether it is responding to treatment.

Question 8

Characteristics of tumour marker

Answer 8

Produced exclusively by a cancer cell
as a response to tumour
development
Sensitivity

Not exclusively by a cancer cell, but
has enough to be distinguished from
production by a normal tissue cell
Specificity

Question 9

An ideal tumour marker

Answer 9

The quality should be included
High sensitivity
High specificity
Can be qualified
Safe
Convenience
Low price

Question 10

Types of Tumour marker (TM)

Answer 10

Circulating tumour markers can be found in the
blood, urine, stool, or other bodily fluids of some
patients with cancer. Circulating tumour markers are
used to:
estimate prognosis
detect cancer that remains after treatment (
residual disease) or that has returned after treatment
assess the response to treatment
monitor whether a cancer has become resistant to
treatment

Tumour tissue markers are found in the actual
tumours themselves, typically in a sample of the
tumour that is removed during a biopsy.
Tumour tissue markers are used to:
diagnose, stage, and/or classify cancer
estimate prognosis
select an appropriate treatment (eg, treatment with a
targeted therapy)

Question 11

tumour
marker in
Oncology

Answer 11

Screening
Diagnosis
Staging
Prognosis

Question 12

TM Screening

Answer 12

Tumour markers play a limited
role for Tumour screening, just
because….
›relatively low sensitivity
›lack of specificity and
relation to Tumour size

Inappropriate for the detection
of small in situ cancer

Question 13

Staging TM

Answer 13

The tumour markers and medical
imaging are complementary in the
pre-therapeutic and post-
therapeutic staging

Question 14

TM Prognosis

Answer 14

The pre-therapeutic level of certain
tumour marker can contribute a
prognostic factor because of links
with…
Metabolic activity
tumour size
Invasion

More valuable in that it is
independent of other usual
prognostic factors for the pathology

Question 15

During
treatment TM

Answer 15

High markers level before treatment
generally
Not only correlate very well with
the therapeutic result but are
sometimes superior to this result
in the assessment of complete
remission

The assay must be considering the
marker half-life when during
treatment and all post-therapeutic re-
evaluation

Question 16

Cancer
Management TM

Answer 16

Specificity and sensitivity
are neither sensitive nor specific
enough to screen for or diagnose
cancer without the support of
other clinical findings.
levels help determine the
amount of cancer present.

Question 17

Dilemma for TM

Answer 17

1) tumour marker levels can be
elevated in people with benign
conditions;
2) tumour marker levels are not
elevated in every person with
cancer, especially in the early
stages of the disease;
3) many tumour markers are not
specific to a cancer
4) the level of a tumour marker can
be elevated by more than one
type of cancer (NCI, 2006).

Question 18

AFP

Answer 18

is a single chain glycoprotein
with a molecular weight of
approximately 70,000 daltons.
serum AFP concentrations
remain low except during
pregnancy, benign liver
diseases, (hepatitis, cirrhosis),
primary hepatocellular
carcinoma, and certain germ cell
tumours.

An elevated level of AFP
strongly suggests the presence
of either primary liver cancer or
germ cell cancer of the ovary or
testicle.
The most important application
of AFP testing in cancer
management is for testicular
cancer.

An AFP test can also be done to detect other, more rare
conditions, such as chromosome (trisomy) syndromes or
omphalocele, a congenital defect in which portions of a
fetus’s intestines protrude through the abdominal wall.

Question 19

Limitations of AFP

Answer 19

AFP is not a screening test for
cancer.

Question 20

CEA

Answer 20

An oncofetal glycoprotein
antigen.
Carcinoembryonic antigen
(CEA) is a normal cell product
that is over-expressed by
adenocarcinomas, primarily of
the colon, rectum, breast, and
lung.

CEA levels may be measured
during treatment with
medicines to destroy cancer
cells (chemotherapy).
This provides information
about how well the
treatment is working.

CEA testing is a reliable test for
recurrent colon cancer if the
original cancer produced this
protein before treatment.

Question 21

PSA

Answer 21

Glycoprotein produced in
prostate epithelial cells.
Its normal physiologic role is as a
liquefying agent for seminal fluid;
only a tiny amount leaks into the
blood, therefore its normal serum
level is usually very low.
Elevated serum levels of PSA
have been associated with
prostate carcinoma.
Elevated levels of Prostate-Specific
Antigen (PSA) may be found in the
blood of men with benign prostate
conditions, such as prostatitis and
benign prostatic hyperplasia (BPH),
or with a malignant growth in the
prostate.

Question 22

hCG

Answer 22

to screen for choriocarcinoma
in women who are at high risk
for the disease, and to monitor
the treatment of trophoblastic
disease.

Question 23

CA-125 (Cancer antigen)

Answer 23

A high-molecular-weight glycoprotein found on the
surface of Mullerian and coelomic epithelial-derived
cell types, and is the best known tumour marker for
epithelial ovarian cancer.

Question 24

CA- 153 (cancer antigen)

Answer 24

A protein made by a variety of cells, particularly
breast cancer cells.
CA15-3 levels can be higher than normal with
cancerous and non-cancerous conditions.
CA15-3 is most often increased in breast cancer
that has spread to other parts of the body.

Question 25

CA-199 (Cancer antigen)

Answer 25

CA19-9 is commonly used as a tumour marker for
some types of cancer of the pancreas.
But this test cannot be used by itself to find
pancreatic or other cancers because:
CA19-9 is also found in healthy adults in small amounts in the
pancreas, liver, gallbladder and lungs.