Cancer Ray M. Merrill, PhD, MPH Department of Health Science Brigham Young University

Did you know? In the United States… 1 in 3 people will develop cancer in their lifetime 1 in 3 people will develop cancer in their lifetime 1 in 8 women will develop breast cancer in their lifetime 1 in 8 women will develop breast cancer in their lifetime 1 in 6 men will develop prostate cancer in their lifetime 1 in 6 men will develop prostate cancer in their lifetime Over 1,400,000 people will be diagnosed with cancer this year Over 1,400,000 people will be diagnosed with cancer this year Over 550,000 people will die from cancer this year Over 550,000 people will die from cancer this year

Fifteen Leading Causes of Death, US, 2004 Rank Cause of DeathNumber of Deaths Percent (%) of Total Deaths Death Rate * Source: US Mortality Public Use Data Tape, 2004, National Center for Health Statistics, Centers for Disease Control and Prevention, Heart diseases652, Cancer553, Cerebrovascular diseases150, Chronic lower respiratory diseases121, Accidents (unintentional injuries)112, Diabetes mellitus73, Alzheimer disease65, Influenza & pneumonia59, Nephritis, nephrotic syndrome, & nephrosis42, Septicemia33, Intentional self-harm (suicide)32, Chronic liver disease & cirrhosis27, Hypertension & hypertensive renal disease23, Parkinson disease17, Assault (homocide)17, All other & ill-defined causes414, *Rates are per 100,000 population and age-adjusted to the 2000 US standard population.

What is cancer? Cancer is a collective name that refers to a group of many diseases with one common characteristic: uncontrolled cell growth or loss of the cell's ability to perform apoptosis (cell suicide). Cancer is a collective name that refers to a group of many diseases with one common characteristic: uncontrolled cell growth or loss of the cell's ability to perform apoptosis (cell suicide). Mutations occur to genes that control the normal process of cell growth and death Mutations occur to genes that control the normal process of cell growth and death Gradual increase in the number of uncontrolled dividing cells Gradual increase in the number of uncontrolled dividing cells Mass of tissue occurs called a “tumor” (also called a neoplasm) Mass of tissue occurs called a “tumor” (also called a neoplasm)

Development of Cancer from genetically altered cell to metastasis

Cancer Tends to Involve Multiple Mutations The formation of cancer usually requires multiple mutations, with the chance increasing for mutations to accumulate and cancer to develop with more years of life (Doll & Peto, 1981). The formation of cancer usually requires multiple mutations, with the chance increasing for mutations to accumulate and cancer to develop with more years of life (Doll & Peto, 1981).

Why do mutations happen? Some cancer-causing mutations are simply spontaneous errors that appear in normal DNA molecules when cells duplicate their DNA prior to cell division Some cancer-causing mutations are simply spontaneous errors that appear in normal DNA molecules when cells duplicate their DNA prior to cell division Some are related to environmental factors/exposures, diet, lifestyle choices or heredity (a few “suseptibility genes” passed down) Some are related to environmental factors/exposures, diet, lifestyle choices or heredity (a few “suseptibility genes” passed down)

Accumulation of mutations in these 3 areas=cancer The mutations that contribute to the development of cancer affect three general classes of gene: The mutations that contribute to the development of cancer affect three general classes of gene: Oncogenes Oncogenes Tumor suppressor genes Tumor suppressor genes DNA repair genes DNA repair genes

Heredity and Cancer Cancer is not considered an inherited illness since 80 to 90 percent occur in people with no family history of the disease Cancer is not considered an inherited illness since 80 to 90 percent occur in people with no family history of the disease E.g., only about 5 percent of breast cancers are thought to be due to inheritance of particular form(s) of a "breast cancer susceptibility gene." E.g., only about 5 percent of breast cancers are thought to be due to inheritance of particular form(s) of a "breast cancer susceptibility gene."

Different Kinds of Cancer Carcinomas Carcinomas Most common types of cancer Most common types of cancer Arise from the cells that cover external and internal body surfaces Lung, breast, prostate, and colon are the most frequent cancers of this type in the United States Arise from the cells that cover external and internal body surfaces Lung, breast, prostate, and colon are the most frequent cancers of this type in the United States Sarcomas Sarcomas Arise from cells found in the supporting tissues of the body such as bone, cartilage, fat, connective tissue, and muscle Arise from cells found in the supporting tissues of the body such as bone, cartilage, fat, connective tissue, and muscle Lymphomas Lymphomas Arise in the lymph nodes and tissues of the body's immune system Arise in the lymph nodes and tissues of the body's immune system Leukemias Leukemias Cancers of the immature blood cells that grow in the bone marrow and tend to accumulate in large numbers in the bloodstream Cancers of the immature blood cells that grow in the bone marrow and tend to accumulate in large numbers in the bloodstream

Tumor Grading/Staging Microscopic examination also provides information regarding the likely behavior of a tumor and its responsiveness to treatment. Microscopic examination also provides information regarding the likely behavior of a tumor and its responsiveness to treatment. A low number grade (grade I or II) refers to cancers with fewer cell abnormalities than those with higher numbers (grade III, IV). A low number grade (grade I or II) refers to cancers with fewer cell abnormalities than those with higher numbers (grade III, IV).

Tumor Grading/Staging Based on the answers to the following questions, the cancer is assigned a "stage." Based on the answers to the following questions, the cancer is assigned a "stage." 1. How large is the tumor, and how far has it invaded into surrounding tissues? 1. How large is the tumor, and how far has it invaded into surrounding tissues? 2. Have cancer cells spread to regional lymph nodes? 2. Have cancer cells spread to regional lymph nodes? 3. Has the cancer spread (metastasized) to other regions of the body? 3. Has the cancer spread (metastasized) to other regions of the body?

Diagnose the presence of cancer Screening tests indicate the possible existence of cancer, a doctor must then perform a biopsy Screening tests indicate the possible existence of cancer, a doctor must then perform a biopsy For leukemias, a small blood sample serves the same purpose For leukemias, a small blood sample serves the same purpose Microscopic examination will tell the doctor whether a tumor is actually present and, if so, whether it is malignant (i.e., cancer) or benign. Microscopic examination will tell the doctor whether a tumor is actually present and, if so, whether it is malignant (i.e., cancer) or benign.

Why Cancer Is Potentially Dangerous A malignant tumor, a "cancer," is a more serious health problem than a benign tumor because cancer cells can spread to distant parts of the body. A malignant tumor, a "cancer," is a more serious health problem than a benign tumor because cancer cells can spread to distant parts of the body.

Cancer Detection and Diagnosis Early detection affects the outcome of the cancer Early detection affects the outcome of the cancer When cancer is found (type and how fast it is growing) When cancer is found (type and how fast it is growing) Invasion Invasion Metastasized Metastasized

Early Cancer May Not Have Any Symptoms Screening methods are designed to check for cancer in people with no symptoms. Some examples of screening methods are: Screening methods are designed to check for cancer in people with no symptoms. Some examples of screening methods are: Pap Test/smear Pap Test/smear Mammograms Mammograms Blood Tests (PSA) Blood Tests (PSA) Fecal Occult Blood Test (FOBT) Fecal Occult Blood Test (FOBT)

Tumor grade and stage are related to cancer survival

What Causes Cancer?

Heredity? Behaviors? Other Factors ? In theory, differences in heredity or environmental risk factors might be responsible for the different cancer rates observed in different countries. In theory, differences in heredity or environmental risk factors might be responsible for the different cancer rates observed in different countries.

Low-Strength Radiation Some atoms give off radiation, which is energy that travels through space. Prolonged or repeated exposure to certain types of radiation can cause cancer. Some atoms give off radiation, which is energy that travels through space. Prolonged or repeated exposure to certain types of radiation can cause cancer.

High-Strength Radiation X-rays or radiation emitted from unstable atoms called radioisotopes X-rays or radiation emitted from unstable atoms called radioisotopes Stronger than ultraviolet radiation Stronger than ultraviolet radiation Can penetrate through clothing and skin and into the body Can penetrate through clothing and skin and into the body High-strength radiation can cause cancers of internal body tissues High-strength radiation can cause cancers of internal body tissues

Examples of Human Cancer Viruses

Viruses A few viruses also can trigger the development of cancer A few viruses also can trigger the development of cancer Cannot reproduce on their own Cannot reproduce on their own Viruses are small infectious agents Viruses are small infectious agents Enter into living cells and cause the infected cell to produce more copies of the virus Enter into living cells and cause the infected cell to produce more copies of the virus Causes the cell to become malignant Causes the cell to become malignant

Bacteria and Stomach Cancer The bacterium H. pylori, which can cause stomach ulcers, has been associated with the development of stomach cancer The bacterium H. pylori, which can cause stomach ulcers, has been associated with the development of stomach cancer

Cancer Risk and Aging

Summary of What Causes Cancer Source: CDC Diet & Physical Activity Tobacco Use Other Factors Environmental & Occupational Factors Sexual FactorsAlcohol Overuse

Ways to prevent cancer: Maintain a healthy weight; Maintain a healthy weight; Eat no more than two or three servings of red meat per week; Eat no more than two or three servings of red meat per week; Take a multivitamin with folate every day; Take a multivitamin with folate every day; Drink less than one alcoholic drink a day; Drink less than one alcoholic drink a day; Eat five or more servings of fruits and vegetables per day; Eat five or more servings of fruits and vegetables per day; Eat more high fiber foods such as whole grains, wheat cereals, bread, and pasta; Eat more high fiber foods such as whole grains, wheat cereals, bread, and pasta; Include cruciferous vegetables in your diet (such as broccoli, cabbage, etc.); Include cruciferous vegetables in your diet (such as broccoli, cabbage, etc.); Do not smoke; Do not smoke; Protect yourself from the sun; Protect yourself from the sun; Avoid certain workplace exposures; Avoid certain workplace exposures; Protect yourself and your partner(s) from sexually transmitted infections; and Protect yourself and your partner(s) from sexually transmitted infections; and Exercise regularly. Exercise regularly.

Quick Quiz 3pts/ques 1. What is the most common cancer for men, women? 1. What is the most common cancer for men, women? 2. What is the common characteristic that makes cells result in cancerous growth? 2. What is the common characteristic that makes cells result in cancerous growth? 3. How and to what extent does genetics play in the development of cancer? 3. How and to what extent does genetics play in the development of cancer? 4. What are the 4 main categories names/kinds of cancer and what type of tissue do each arise from? 4. What are the 4 main categories names/kinds of cancer and what type of tissue do each arise from?

Quick Quiz, cont 5.Compare benign vs malignant 5.Compare benign vs malignant 6. Using no more that 5 sentences, describe how a genetically altered cell becomes cancer that has spread though the body 6. Using no more that 5 sentences, describe how a genetically altered cell becomes cancer that has spread though the body 7. Describe I-IV grading system for cancer 7. Describe I-IV grading system for cancer 8. How and to what extent does genetics play in development of cancer? 8. How and to what extent does genetics play in development of cancer?