1. Cancer Overview

2. Statistics
In Canada, cancer is the leading cause of death, followed by heart disease.
Approximately 75,500 died from cancer in Canada in 2013
There were approximately 188,000 new cases of cancer in Canada in
The lifetime risk of developing cancer is 1 in 2 men, and 1 in 3 women.

3. The Global Burden of Cancer 2000
Men
Women
5.3 million cases
3.5 million deaths
4.7 million cases
2.7 million deaths
Lung Breast Colon/Rectum
Stomach
Liver Prostate Cervix uteri Oesophagus
Bladder Non-Hodgkin Lymphoma Leukaemia Oral cavity Pancreas Kidney
902
337
810
293
105
370
499
446
255
234
558
318
241
405
398
384
166
165
543
204
471
233
279
133
227
111
260 76 99 33
167
121 93 68
144
113
109 86
170 97 47 81
Incidence Mortality
116
112
119
101 71 34 57
Ovary
192
114
1000
800
600
400
200 0
(Thousands)
200
400
600
From: D.M. Parkin The Lancet Oncology 2: (2001)

5. Objectives for Today’s Class
Define cancer and cancer terminology (benign/malignant, carcinogenesis, metastasis)
Identify and explain the following:
the characteristics of malignant/cancer cells, and how they differ from normal noncancerous cells
the types of cancer
the stages of cancer
the possible causes of cancer

6. What is Cancer?
“Cancer” is the name for a group of diseases caused by an uncontrollable growth and spread of abnormal cells.
These abnormal cells don’t follow the normal course of cell growth and replication.
Oncology is the study of cancer.

7. Cancer Cells
“Carcinogenesis” is the process by which a normal cell is transformed into a malignant, cancerous cell.
Tumours are classified as either benign (noncancerous) or malignant (cancerous).
Both types of tumors involve abnormal cell growth, but cancer cells are cells that have undergone alterations which make them look and function differently than normal cells.

9. Benign vs. Malignant

10. What Are the Characteristics of Malignant Cancer Cells?
Cell Division and growth – uncontrolled, rapid cell division and growth (normal cells have controlled growth rates); cancer cells have a larger nucleus than normal cells
Invasion and Spread – ability to move within the body and survive in another part (unlike normal cells, cancer cells not inhibited by crowded conditions)

11. What Are the Characteristics of Malignant Cancer Cells?
Poor Differentiation/mutation – cancer cells are poorly “differentiated”. Differentiation is the process of normal cells going through physical and structural changes to develop and form different tissues in the body. The more that a cell looks and acts like a normal cell from the parent tissue, the more differentiated it is.

12. DNA Repair Genes
The DNA in every cell in your body is under constant assault from a variety of directions. But cells contain many different proteins whose job is to repair damaged DNA. Thanks to these, the vast majority of DNA damage is repaired immediately, with no ill effects.
But if the DNA damage occurs to a gene that makes a DNA repair protein, a cell's ability to repair itself will be reduced, and this can allow errors to accumulate in other genes over time. This can cause cancer.

13. Normal and Abnormal Cell Growth

14. Invasion and Spread
“Metastasis” refers to the spreading of tumor cells beyond the “primary tumor”, which is the original tumour.

15. For a cancer cell to spread, it must be able to do two things that the normal cell it grew from could not:
It must be able to leave its usual environment into another environment (ie., either directly or travel through the blood or lymph system) – this process is called invasion.
When it arrives at its new location, it must be able to make new blood vessels grow around it and supply it with oxygen and nutrients, a process known as angiogenesis.

16. Metastatic Cancer

17. Carcinoma in situ
This is the early stage of cancer that has not invaded organs or the “basement membrane”.

19. Types of Cancer
Cancers can be broadly grouped into different types, depending on which tissues they come from (often prefixed by the specific cell):
Carcinomas – the most common types of cancer, arise from the cells that cover external and internal body surfaces. Lung, breast, and colon are the most frequent cancers of this type.
Sarcomas – cancers arising from cells found in the supporting tissues of the body such as bone, cartilage, fat, connective tissue and muscle.

20. Types of Cancer
Lymphomas – cancers that arise in the lymph nodes and tissues of the body's immune system.
Leukaemias – cancers of the immature blood cells that grow in the bone marrow and tend to accumulate in large numbers in the bloodstream.
Adenomas are tumours that come from glandular tissue like the thyroid, the pituitary gland the adrenal gland. They are often benign.

21. Types of Cancer

22. Stages of Cancer
Stage 0 – Cancer cells that are still in the location where they started and have not spread.
Stage 1 – Localized cancer that has spread into nearby tissues. It has not yet spread to lymph nodes or other areas.
Stage 2 – Cancer has spread to a regional area or into nearby tissues or lymph nodes.

23. Stages of Cancer Stage 3 – More advanced regional spread than Stage 2.
Stage 4 – Cancer has spread to distant parts of the body. This stage is often referred to as metastatic cancer, or a cancer that has spread to other areas of the body.

24. What Causes Cancer?

25. Possible Sources… Heredity and Age Immunity Occupational/Environmental
Social/Psychological
Dietary
Lifestyle (smoking, obesity)
Physical
Viral/Bacterial
Medical/Hormonal

26. Heredity (and age)
People with a family history of cancer are at greater risk of developing the same types of cancer
77% of all cancers occur in people aged 55 years of age or older (weakening of immune system)

27. Immunity
A strong healthy immune system can help prevent cancer from forming
Diseases that weaken the immune system can allow cancers to form and spread

28. Occupational And Environmental Factors
Asbestos
Nickel
Chromate
Benzene
Arsenic
Radioactive substances
Coal tars
Herbicides/pesticides

29. Social And Psychological Factors
Stress has been implicated in increased susceptibility to several types of cancers
Sleep disturbances, severe depression, or other psychological factors may weaken the body’s immune system

30. Diet
Many artificial food additives when ingested may form potential carcinogens
Pesticide and herbicide residues in food
Preservatives
Artificial Hormones

31. Lifestyle – Smoking Single biggest cause of cancer
25-40% of smokers die in their middle age
9 in 10 lung cancers are caused by smoking
Tobacco smoke was first shown to cause cancer in 1950
Studies have shown that people who smoked cigarettes a day had 26 times the lung cancer risk of non-smokers
People who smoked less than 15 cigarettes a day still had 8 times the lung cancer risk of non-smokers.

32. Lifestyle – Obesity
Highly caloric diet, diet rich in fat, refined carbohydrates and animal protein
Low physical activity

33. Physical Causes Ultraviolet radiation Sunlight
Certain industrial sources
Radiation
Radon
Cancer treatment

34. Viral and Bacterial Factors
Herpes-related viruses may be involved in the development of leukemia, Hodgkin’s disease, cervical cancer, and Burkitt’s lymphoma;
The virus, associated with mononucleosis, may contribute to cancer;
Human papillomavirus (HPV), virus that causes genital warts, has been linked to cervical cancer;
The bacteria that causes ulcers are a major factor in the development of stomach cancer.

35. Medical and Hormonal Factors
Some medical treatments actually increase a person’s risk for cancer;
Chemotherapy used to treat one form of cancer may increase risk for another type of cancer.

36. World Health Organization Statistics
In 2020, 15 million people will die from cancer;
Why?
Aging population
Obesity
Smoking

37. References/Sources
Cooley, Candy, Manager National Genetics Education and Development Centre “Introduction to Cancer Basics”., (online lecture March 2009).
Currin, Morag. Oncology Esthetics, A Practitioner’s Guide.
Dr. Manash K. Paul. “Cancer and Therapeutics”. Department of Biology, Indian Institute of Science Education and Research, Mohali,