Cancer Epidemiology

From Inside Cancer Wiki

Cancer Epidemiology

Epidemiology is the study of disease distribution and the factors that influence the health of human populations. Cancer epidemiology focuses specifically on factors that influence the distribution of cancer in the population with the hopes of determining the cause of the disease. This module investigates the distribution, factors, potential causes and possible modes of prevention of prostate cancer.

Lesson Overview

The activity begins in Part A by engaging students in an examination of hallmarks of cancer by having them work through that section of the Inside Cancer web site. This section then introduces the students to the epidemiology of the disease by working through the “Causes and Prevention” section of the web site. Part B focuses on the epidemiology of prostate cancer by having students investigate diet as a potential factor leading to this type of cancer. With diet established as a key factor in the high incidence of prostate cancer in the western world, students move on to Part C to consider the role of diet in the biological process that lead to the development of this type of cancer. Finally, students synthesize the knowledge they have obtained into a pamphlet that includes information on the epidemiology of this disease and a set of recommendations for its prevention. The parts of this lesson may be conducted sequentially or independently from one another.

Goals and Objectives

Students will be able to:

• develop a familiarity with and understanding of the hallmarks of cancer.

• recognize that the worldwide distribution of different types of cancers provides insight into the causes of the specific diseases.

• explain the role diet plays in the influencing the frequency of prostate cancer.

• develop an understanding of how specific carcinogens from food lead to the development of prostate cancer.

• synthesize the information provided to propose a prevention plan that emphasizes consideration of lifestyle choices.

Common Misconceptions

Students often think:

• that all cancers are the same.

• that exposure to synthetic chemicals or pollutants is a major cause of cancer.

• lifestyle, including diet, has little impact on the chance of developing cancer.

• that dietary supplements taken orally work in the same manner as when these chemicals are found in food.

The Lesson

Preparation Before class: (materials, handouts etc.)

Print out or post the lesson handout and the accompanying Powerpoint slide slow

Lesson handout: Powerpoint slide show:

During class

In order for students to investigate the epidemiology of cancer, it is necessary for them to have a firm understanding of the hallmarks that characterize the disease. Have the students read through the “Hallmarks of Cancer” section of the Inside Cancer web site and construct a table as instructed in the section 2 of Part A. For more efficient use of class time it is suggested that this be done as an at-home assignment. When the students return to class, have them complete steps (ii) and (iii) of section 2, part b. If computers are available, you may choose to continue to work in groups of 2, having the students complete sections 3 – 4 of this section, convening the class as a whole for periodic discussion of the questions they are addressing. The “take-home” lesson from the previous work is the impact that factors such as culture and lifestyle choices can have on the incidence of cancer. In Par B of this part of the lesson students will focus their study of the epidemiology of cancer on the influence of diet on the incidence of prostate cancer. They will begin this examination by gathering information on different regional diets. Direction for gathering this sort of information has been provided, although numerous sources exist. Depending on the school or wider community, this information can be obtained through personal interviews, although this may require more time in order to complete the activity. It is important to recognize that all that is needed here are examples of representative foods from these diets. With examples of traditional foods in hand the table provided in the lesson can be completed. As students move on to Part C, an in-depth study of the cause of prostrate cancer as a result of the chemical composition of food or its preparation technique is presented. The biology here can get complicated, so a PowerPoint presentation is included to provide additional background. This PowerPoint can be read by students independently or presented by the teacher in the form of class lecture. The goal of Part D is for students to synthesize the information they have acquired into a pamphlet directed at the general public informing them of the epidemiology of prostate cancer. The pamphlet should present information on the worldwide distribution of the disease, the correlation with diet, the molecular biology of the genesis of the disease, and suggestions for prevention. Guidelines for executing the pamphlet assignment are provided in the lesson.

Time required'

Time allotment for this lesson is dependent upon the extent to which at-home time is used to complete various sections. Below is a list of those components of the lesson that can effectively be completed by the students at home and those best suited for in-class work.

• Part A

➢ Sections 1-2, 40 minutes at home, 15 minutes in class

➢ Sections 3-4, 15 minutes at home, 20 minutes in class with associated discussion

• Part B

➢ Section 2 – this may take more than one night if students choose to complete interviews with community members. (45 minutes)

• Note, the groups listed are just suggestions. Substituting ethnic/cultural groups more representative of your classroom works perfectly, but it is important to include the classic “western diet” in the comparison study.

➢ In-class comparison of diets researched – 15 – 20 minutes depending upon number of groups.

• Part C

➢ Section 1 – this can be tackled both at home and in class

• Both the powerpoint slide show and the Inside Cancer slides will take about 20 minutes to complete.

➢ Section 2

• Part a - reading the articles associated with the 5th bullet point (45 minutes).

➢ Final Assignment – Adequate completion of the pamphlet will most likely take 2 days. This could, therefore, be a week-end assignment.

Student Handouts for the Lesson Plan

Media:The Cancer Epidemiology: The Causes and Prevention of Prostate Cancer document can be printed out for students prior to class and handed out for them to work on. However, because the links to the necessary online sites are embedded in the text, it may be easier to have students access the document electronically so navigation to the required sites is made easier.

The Powerpoint slide should be downloaded prior to beginning the lesson. The slide can be printed out for students or they can read through the material online. It may also be appropriate for the teacher to present this information to the class via a short lecture. The slide show can be accessed here :

Alternative Assessments

• Teachers may choose to collect and evaluate the answers generated by students to questions asked throughout the activity.

• A short quiz on the hallmarks of cancer and the molecular biology of prostate cancer could be used to assess understanding.

• Publish the pamphlets and make them available to the school and greater community.

Suggestions for Extended Learning

• Why do you think the incidence and mortality data for prostate cancer for Hispanics, Asians, and Native Americans and Alaskans are only provided after 1992?

Glossary

• Benzo[a]pyrene – A class of Polycyclic Aromatic Hydrocarbon that was first identified carcinogen of its class. This compound in produced as a result of burning organic matter.

• CpG Dinucleotide – A cytosine nucleotide next to a guanine nucleotide on the same strand of DNA.

• CpG Islands – Regions in DNA that have a preponderance of CpG dinucleotides. These regions in the genome tend to be between 150 – 350 kilobases in length.

• DNA Repair Enzymes – A class of enzymes responsible for correcting errors in the nucleotide sequence in DNA. These enzymes function during DNA replication to proofread the newly synthesized strand or work when DNA is damaged by chemical or physical means.

• Epidemiology – the study of the frequency and distribution of disease in a population.

• Glutathione – An anti-oxidant found in the cells that prevents oxidative damage from occurring in cells due to the presence of certain compounds.

• Glutathione-S-Transferase – The enzyme responsible for catalyzing the reaction between glutathione and an oxidizing molecule. The reaction neutralizes the oxidizing capabilities of the compound, preventing it from damaging the cell.

• Heterocyclic Amines – A class of carcinogenic compounds produced through certain food preparation techniques, for example, grilling.

• Methylation – The addition of methyl, -CH3, groups to cytosine residues in a DNA molecule.

• Oxidants – Chemically active compounds typically containing oxygen that promote the loss of electrons in other compounds in the cell. The compounds can be produced as a result of normal metabolic function or as a result of exposure to toxins, radiation, or drugs.

• Polycyclic Aromatic Hydrocarbons – Chemical compounds composed of fused rings of carbon. These compounds are naturally found in oils and fuels and can be the product of chemical reactions such as combustion. The level of their toxicity is dependent upon the structure of the molecule.

• Promoter – the region of a gene where transcription is initiated. It is the site for the binding of RNA Polymerase.

Education Standards

• Understanding Scientific Inquiry

➢ Formulating and revising scientific explanations and models using logic and evidence

➢ Communicate and defend a scientific argument

• Developing an understanding of the cell and molecular basis of heredity

➢ Genetic information is carried in DNA molecules

➢ Changes in DNA occur that result in changes to cell structure and function

• Developing an understanding of personal and community health and population growth

➢ Living organisms have the potential to produce populations of infinite size, but are limited by resource availability

➢ Carrying capacity is the maximum number of individuals that can be supported in a particular environment

➢ Selection of foods and eating patterns determine nutritional balance and overall health

• Science as a human endeavor

➢ Individuals and teams have contributed and will continue to contribute to the scientific enterprise.

Teacher Answer Key

Teacher answer key can be accessed here: