CancerCancer Cancer is one of the most Cancer is one of the most

common diseases in the common diseases in the developed world:developed world: 11 in in 44 deaths are due to cancer deaths are due to cancer 11 in in 1717 deaths are due to lung cancer deaths are due to lung cancer Lung cancer is the most common cancer in Lung cancer is the most common cancer in

menmen Breast cancerBreast cancer is the most common cancer in is the most common cancer in

womenwomen There are over There are over 100100 different forms of cancerdifferent forms of cancer

What causes What causes cancer?cancer?

The division of normal cells is precisely The division of normal cells is precisely controlled. New cells are only formed controlled. New cells are only formed for for growthgrowth or to replace or to replace deaddead ones. ones.

Cancer arises from the Cancer arises from the mutationmutation of a of a normal gene.normal gene.

Cells that are old or not functioning Cells that are old or not functioning properly should self-properly should self-destructdestruct and be and be replaced by replaced by newnew cells. cells.

However, cancerous cells do not self-However, cancerous cells do not self-destruct and continue to divide destruct and continue to divide rapidlyrapidly producing producing millionsmillions of new cancerous of new cancerous cells.cells.

CancerCancer Cancerous cells Cancerous cells

divide repeatedly divide repeatedly out of controlout of control even even though the body though the body does not need them. does not need them. They crowd out other They crowd out other normalnormal cells and cells and function function abnormallyabnormally. They . They can destroy the can destroy the correct functioning of correct functioning of major organs.major organs.

CancerCancer Mutated genes Mutated genes

that cause that cause cancer are cancer are calledcalled oncogenes.oncogenes.

The study of The study of cancer is called cancer is called oncology.oncology.

CancerCancer A factor which brings about a A factor which brings about a

mutation is called a mutation is called a mutagen mutagen (mutagenic).(mutagenic).

Any agent that causes cancer Any agent that causes cancer is called a is called a carcinogen carcinogen and is and is described asdescribed as carcinogenic. carcinogenic.

So some mutagens are So some mutagens are carcinogenic.carcinogenic.

CarcinogensCarcinogens Hereditary predisposition – Hereditary predisposition –

Some families are Some families are more more susceptiblesusceptible to getting certain to getting certain cancers. Remember cancers. Remember you canyou can’’t t inherit cancerinherit cancer its just that you its just that you maybe more susceptible to maybe more susceptible to getting it.getting it.

CarcinogensCarcinogensRadiation – Radiation – X X Rays, UV lightRays, UV light

Chemicals – Chemicals – tar tar from cigarettesfrom cigarettes

Virus infection – Virus infection – papilloma virus can papilloma virus can be responsible for be responsible for cervical cancer.cervical cancer.

TumorsTumors Disorganized Disorganized clumpsclumps of cancer cells of cancer cells A tumor as small as a gram can send A tumor as small as a gram can send

out a out a millionmillion tumor cells into tumor cells into bloodblood vesselsvessels a day. a day.

Benign or Benign or Malignant?Malignant?

Benign tumors are ones that Benign tumors are ones that cannotcannot spreadspread out to other out to other places in the body. They are places in the body. They are completely completely localizedlocalized..

Benign or Malignant?Benign or Malignant? Malignant tumors can Malignant tumors can spreadspread

from the original site and cause from the original site and cause secondary tumors and harm to other places in the body. . This is called This is called metastasismetastasis. . The word “cancer” is used in The word “cancer” is used in reference to reference to malignantmalignant tumors.tumors.

Metastasized Colon Metastasized Colon CancerCancer

How do Tumors Hurt How do Tumors Hurt the Body?the Body?

They They interfereinterfere with neighbouring with neighbouring cells by cells by blockingblocking blood vessels, blood vessels, the gut, glands, lungs etc.the gut, glands, lungs etc.

They need a huge amount of They need a huge amount of nutrientsnutrients to sustain the rapid to sustain the rapid growth and division of the cells. growth and division of the cells. This takes nutrition away from the This takes nutrition away from the rest of the bodyrest of the body’’s healthy cellss healthy cells

How is Cancer How is Cancer Treated?Treated? Radiation-Radiation-Using a

certain type of energy such as intense xrays, it destroys cancer cells and minimizes tumors.

Chemotherapy-Chemotherapy-Utilizes medications to damage the DNA of cells, prohibit their duplication and eliminate their existence.

Side EffectsSide Effects Chemotherapy

Unfortunately, the drugs cannot differentiate between the infected and non-infected cells, causing impairment of healthy cells in the process. 

Radiation Feeling very tired (fatigue) Skin changes Not wanting to eat (appetite loss)

RadiationRadiation Depends on the part of the body being

treated. For instance, if you get radiation to your head, you might have hair loss. Or if you get radiation to your chest, you might have a cough or sore throat. The skin over the treatment area might look sunburned.

Cancer ResearchCancer Research What steps to scientists use to try to find a What steps to scientists use to try to find a

cure for a particular cancer?cure for a particular cancer? Narrow it down to a very specific disease, Narrow it down to a very specific disease,

in this case one specific form of cancer in this case one specific form of cancer (Ex: Not just lung cancer, but small cell (Ex: Not just lung cancer, but small cell lung cancer)lung cancer)

Secure funding for the research.Secure funding for the research.

***Diseases or cancers that are rare often do ***Diseases or cancers that are rare often do not receive large amounts of funding. Why?not receive large amounts of funding. Why?

Clinical ResearchClinical Research Scientists may spend years alone or in Scientists may spend years alone or in

teams testing a variety of drug teams testing a variety of drug combinations on cancerous cells to find combinations on cancerous cells to find something that works.something that works.

Once they find a drug that seems to Once they find a drug that seems to work, they follow strict guidelines on work, they follow strict guidelines on testing the drug on animals such as testing the drug on animals such as mice.mice.

Clinical ResearchClinical Research What about human trials?What about human trials? There are very strict rules about using There are very strict rules about using

experimental drugs on humansexperimental drugs on humans It must be volunteer!It must be volunteer! Participants must agree to the termsParticipants must agree to the terms Participants are chosen based on Participants are chosen based on

certain characteristics such as age, certain characteristics such as age, race, gender, other preexisting race, gender, other preexisting medical conditions. medical conditions.

Clinical ResearchClinical ResearchAs with any experiment, there must As with any experiment, there must be a control group.be a control group.One group of participants will receive a One group of participants will receive a placebo – a similar looking medicine that placebo – a similar looking medicine that has no actual drug present and provides has no actual drug present and provides no benefit (sugar pill)no benefit (sugar pill)Participants do not know whether they Participants do not know whether they are receiving the actual drug or the are receiving the actual drug or the placebo.placebo.Is this ethical?Is this ethical?

Clinical ResearchClinical Research Without a control group, Without a control group,

would the experiment be valid would the experiment be valid at all?at all?

How would this affect How would this affect research?research?

What about animal research? What about animal research?

Animal ResearchAnimal Research

British law protects vertebrate animals such as mammals, fish and birds and these are the animals which are counted by government every year. Most research animals are rodents, followed by fish and birds. Dogs, cats and monkeys together represent two in every 1000 animals used in UK research.

Invertebrate animals such as fruit flies and worms are used in large numbers in research but are not protected by the law or counted.Numbers relate to procedures on animals in Great Britain in 2012:Rats, mice and other rodents, all purpose-bred laboratory species 82%Fish, amphibians, reptiles and birds 16.2%Sheep, cows, pigs and other large mammals 1.5%Small mammals, excluding rodents, mostly rabbits and ferrets 0.3%Dogs and cats, all bred for research, no strays or unwanted pets can be used 0.12%Primates, mainly marmoset and macaque monkeys 0.07%