Cape Biology Unit 2 Module 3

1. Module 3: Applications of Biology
Topic: Social & Preventative Medicine
(Cancer)
Institution: Montego Bay Community College
Lecturer: Mrs. S. Desouza

2. Information Compilers:
 Hariel Walker
 Joelle-Ann Griffiths
 Tiann Peterkin
Editors:
 Le-Jay K. Robinson
 Daena Ruddock
Power pointer: Le-Jay K. Robinson

3. To discuss the reason for regional distribution
of cancer and this will be done by:
 Outlining the role of environmental
hazards, food additives, viruses and genetic
factors.
 Implications of symptom awareness and
failure to seek treatment in management of
the disease

4.  A disease caused by an uncontrolled division of
abnormal cells in a part of the body. [1 mark]
 Cancer refers to any one of a large number of diseases
characterized by the development of abnormal cells
that divide uncontrollably and have the ability to
infiltrate and destroy normal body tissue. [2 mark]

5.  Brain Tumor
 Eye Cancer
 Nasal Cavity Cancer
 Esophagus Cancer
 Lung Cancer
 Breast Cancer
 Stomach Cancer

6.  Cervical Cancer
 Prostate Cancer
 Stomach Cancer
 Lung Cancer
 Colorectal Cancer

8. Formation

9.  Cancers are a result of uncontrolled cell division. The type
of nuclear division involved is mitosis. The problem is
caused by mutations or abnormal activation of the genes
which control the division. When the genes are abnormal
they are called oncogenes. A single faulty cell may divide
to form a clone of identical cells. Eventually an irregular
mass of relatively undifferentiated cells called a tumor is
formed. Tumor cells can break away and spread to other
parts of the body, particularly in the bloodstream or
lymphatic system, causing secondary tumors or
metastases. This process is called metastasis.

11. Causes
of
Cancer

12.  Retroviruses are RNA viruses which, when they invade
animal cells, use the enzyme reverse transcriptase to
make DNA copies of the viral RNA. The DNA is
inserted into the host DNA where it may stay and be
replicated for generations of cells.
 An example of this is the human immunodeficiency
virus (HIV), which contains a gene that alters host
cells, switching them on and causing them to become
malignant. The genes become oncogenes.

13.  DNA viruses contain DNA as their hereditary material.
Some contain there own oncogenes which can cause
uncontrolled cell division of host cells.
 An example of this is papilloma viruses which causes
warts.

14.  About 5% of human cancers show a strong genetic
predisposition, in other words they tend to run in
families. More than 40 types of cancer including
breast, ovary and colon cancer come into this category.
 The genes responsible may be oncogenes, or genes
which lead to failure to kill cancer cells.

15.  This includes X-rays, ɣ-rays and particles from the
decay of radioactive elements. The radiation causes
the formation of chemically active and damaging ions
inside cells which can break DNA strands or cause
mutations.

16.  This is the most common form of carcinogenic
radiation and is non-ionising. DNA absorbs UV-light
and the energy is used in converting the bases into
more reactive forms which react with surrounding
molecules.
 However Prolonged exposure can result in melanoma
which is highly malignant.

17.  Radon gas is a natural source of radiation released
from certain rocks such as granite. It may accumulate
in houses in areas where these rocks are found.
Exposure to this radiation has been linked to the
development of leukemia, lung, kidney and prostate
cancers.

18.  Many chemicals are now considered as carcinogenic.
The first example was described in 1775 as soot and
coal tar, when chimney sweeps were discovered to
develop scrotum cancer. Tobacco smoke contains
chemicals responsible for lung cancer, the most
important of these are polycyclic hydrocarbons which
are converted in the body to carcinogens.

20. Symptoms

21.  A symptom is a signal that’s felt or noticed by the
person who has it, but may not be easily seen by
anyone else. For example, weakness, aching, and
feeling short of breath may be symptoms of
pneumonia.
 Cancer is a group of diseases that can cause almost any
sign or symptom. The signs and symptoms will depend
on where the cancer is, how big it is, and how much it
affects the organs or tissues. If a cancer has spread
(metastasized), signs or symptoms may appear in
different parts of the body.

22.  A cancer may cause symptoms like fever, extreme
tiredness (fatigue), or weight loss. This may be because
cancer cells use up much of the body’s energy supply,
or they may release substances that change the way the
body makes energy from food. Cancer can also cause
the immune system to react in ways that produce these
signs and symptoms.

24.  Surgery: can be used to diagnose, treat, or even help
prevent cancer in some cases. Most people with cancer
will have some type of surgery. It often offers the
greatest chance for cure, especially if the cancer has
not spread to other parts of the body.
 Chemotherapy: is the use of medicines or drugs to
treat cancer.
 Radiation Therapy: uses high-energy particles or
waves to destroy or damage cancer cells. It is one of the
most common treatments for cancer, either by itself or
along with other forms of treatment.

25.  Targeted Therapy: is a newer type of cancer
treatment that uses drugs or other substances to more
precisely identify and attack cancer cells, usually while
doing little damage to normal cells.
 Immunotherapy: is treatment that uses your body's
own immune system to help fight cancer.
 Photodynamic therapy: is a treatment that uses
special drugs, called photosensitizing agents, along
with light to kill cancer cells. The drugs only work after
they have been activated or "turned on" by certain
kinds of light.

26.  An untreated cancer will continue to grow indefinitely , however
not all cancers are the same. Some grow very fast (within 48
hours) and some grow very slow (up to 30 years). A cancer also
has the ability once it reaches a certain point to replicate itself by
seeding the body with millions of 'new mutated cancer cells' ,
this is called metastasis. When a cancer becomes metastatic it
will shed 'cancer cells' into the blood stream or lymphatic system
and send new cancer colonies anywhere in the body. Those new
cells will lodge in the lung, liver, brain, bones, or any other
system in the body and grow new cancer tumors which in turn
will continue the cycle. Eventually the cancer will consume the
entire body and begin to affect the normal functioning of body
systems which will lead to organ failure and death. It is possible
for the entire body cavity to be filled with tumors, they can also
erupt through the skin and spread on the surface as well.