CELL BIOLOGY AND CANCER

.01 Cancer types, incidence, pre-disposition, and risk factors

CANCER WHERE DID IT GET ITS NAME?

A. Cancer facts Group of 100 diseases that develop across time

2. Can develop in virtually any of the body’s tissues

3. Characterized by uncontrolled cell division

4. Hereditary & environmental factors contribute to cancer development

5. Second leading cause of death in U.S.

6. Men have one in two lifetime risk, women one in three ACTIVITY 1 – FACES OF CANCER

Type of Information FAMILY HISTORY (write in the number of “yes” and “no” answers for all teams) YES _____ NO ______

NUMBER OF PEOPLE DIAGNOSED WITH CANCER TOTAL OF ALL TEAMS 0-19 YEARS _____ 20-39 YEARS ______ 40-59 YEARS ______ 60 AND OLDER ______

TYPE OF CANCER WRITE IN THE NUMBER OF EACH BLADDER __ LEUKEMIA __PROSTATE ___ BRAIN ___ LUNG ___ RETINOBLASTOMA ___ BREAST ___ ORAL CAVITY ___ SKIN ___ CERVICAL ___ OVARIAN ___ UTERINE ___ COLON ___ PANCREATIC __ OTHER ___

POSSIBLE RISK FACTORS (LIST ANY POSSIBLE RISK FACTORS)

B. Types of cancer Benign – not cancerous, does not invade nearby tissue or spread to other parts of the body (will grow & push organs out of way) Malignant – cancerous; can invade nearby tissue and spread to other parts of the body (will invade organs by enzymes eating through tissue)

Metastatic – spread through body by hemogenic (blood) or lymphogenic (lymph) Type depends on cause & location 5. Each type has its own growth rate, prognosis, and treatability

C. Incidence increases with age (old men have better chance of developing cancer) Develops over time and could result from different causes Can occur at any age and in any location

D. Inherited predisposition Can inherit a cancer – susceptible mutation Occurs in all the body’s cells

E. Risk Factors Increase a person’s risk for developing cancer Cigarette smoking Exposure to the sun Exposure to carcinogens Females – family history of breast cancer Fair skin Chemicals, radiation, & viruses

F. Chance of surviving cancer increases with early detection & treatment Incidence rate – number of new cases per year per 100,000 persons Mortality rate – number of deaths per 100,000 persons per year Survival rate – proportion of patients alive at some point after their diagnosis of cancer (chance of cure)

.02 Causes & development of cancer Many different agents can cause cancer (Carcinogens) sun Radiation Chemicals smoking

Cancer involves the uncontrolled division of body cells. B. Cancer represents a breakdown of the processes that regulate the growth of normal cells & tissues. Cancer involves the uncontrolled division of body cells. Cell division is normally precisely regulated Cell cycle regulation is accomplished by two major types of genes

4. Cancer causing agents often damage genes 5. When damage occurs to genes that regulate the cell cycle, signals that inhibit cell division can change leading the cell to divide more often that it normally would (cancer cells multiply rapidly, taking up space and nutrients from the normal cells

C. Cancer develops from genetic damage to cells across time Cigarette smoke can damage genes that regulate growth of normal cells

D. Cancer research leads to understanding normal cell cycle and new strategies for treating cancer

E. Stages of tumor development tumor – mass of cancer cells 1. Mutation – damage to genes causing cells to alter (1st stage of tumor development) 2. Hyperplasia – altered cells & its descendents grow & divide too often

3. Dysplasia – one of these cells experiences another mutation that further increases its tendency to divide. This cell’s descendents divide excessively & look abnormal

In situ (tumor) – Tumor formed from these mutated, rapidly dividing cells stays contained within its tissue of origin Invasive cancer (malignant) – if some cells experience additional mutations that allow the tumor to invade neighboring tissues & shed cells into the blood or lymph, the tumor is malignant.

6. Metastases – escaped cells may establish new tumors at other locations in body

Cancer has been described as a single disease and a hundred diseases Single disease – all cancers display uncontrolled growth, the ability to expand without limit. Hundred diseases – cancer can appear as a result of different causes, in a variety of sites within the body, and that each type of cancer displays its own growth rate, prognosis, and treatability.

The discovery that all cancer involves a fundamental disruption in the growth of cells and tissues suggests that to understand cancer, we need to understand the events and processes that occur as both normal and abnormal cells grow and divide.

In fact, much cancer research across the past two decades has focused on this challenge. This research has revealed a complex picture of how two classes of genes, called proto-oncogenes and tumor suppressor genes, normally regulate the intricate sequence of cell cycle events.

And it also has revealed how the accumulation of mutations in these genes can contribute to the development of an altered cell, a cell that has lost the normal controls on cell division. Activity 2

.03 Genetic damage & mutation Cancer results from the accumulation of genetic damage to cells across time multiple exposure over time Mutation causes change in the way the cell functions or develops

B. Cancer cells differ from normal cells Shape changes (appearance changes) Changes in their dependence on growth factors Multitude of biochemical differences

A B C D – moles A – assymetrical B – border C – color D – diameter (bigger than a pencil eraser)

C. Cancer is a multi-step process, which explains: Increased incidence of cancer with age Development of cancer decades after exposure to carcinogens (severe sunburns as a child) Increased incidence of cancer among people with inherited dispositions (they are more likely to develop cancer than the general population) Activity 3

.04 Improve personal and public health A. Good choices can reduce an individual’s risk of developing cancer 1. Levels of cancer prevention A. Individual behavior changes – develop healthy behavior habits B. Health care providers – perform counseling & routine screening

c. National level – government regulations to minimize public exposure to known carcinogens d. International level – actions of developed countries bring cancer worldwide

2. Attention to ethical & public policy issues Children wear protective headwear & clothing during peak hours of UV exposure would prevent most skin cancers

B. Risk factors for skin cancer Excessive exposure to UV (ultraviolet) radiation – damages skin cells Fair complexion Occupational exposure to substances Known carcinogens: a. coal tar b. Creosate c. Arsenic Compounds d. Radium

C. Good choices can improve an individual’s chance of survival if he/she develops cancer Improved detection Improved treatment Activity 4

Ethics is a process of rational inquiry D. Ethical values sometimes conflict in public policy debated about strategies for reducing the risk of cancer Ethics is a process of rational inquiry Ethics requires a solid foundation of information & careful interpretation of that information

Public policy may invade an individual’s freedom and autonomy 3. There are often competing, well-reasoned answers to what is right & wrong, or good or bad Ex: Public policy may invade an individual’s freedom and autonomy Banning smoking in public places Activity 5

A PROPOSED STATUTE MANDATORY USE OF SKIN PROTECTION FOR ALL INDIVIDUALS UNDER THE AGE OF 18 Whereas it is well documented that only 15 percent of Americans regularly wear a sunscreen when they are outside, and 25 percent never wear sunscreen.

Whereas there is a direct link between the sun’s ultraviolet (UV) rays and melanoma, the deadliest form of skin cancer. Whereas there were more than 42,000 new cases of malignant melanoma diagnosed in 1999. Whereas more than 7,000 Americans die each year from melanoma.

Whereas disruption of the earth’s ozone layer by atmospheric chemical pollution may lead to rising levels of UV radiation. Whereas 80 percent of a person’s UV exposure occurs prior to age 18. Be it enacted by the Federal Statues that:

All individuals under the age of 18 are required to wear headgear and clothing that covers 90 percent of the extremities while outside during peak hours of UV exposure. This covering shall occur in all public locations that are currently under federal jurisdiction, including public school property, recreation sites, federal buildings, and work sites supervised by employers that are overseen by OSHA regulations.