Cancer causes & types

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Transcript of Cancer causes & types

T H E B A S I C S

Chapter 13

Cancer: Reducing Your Risk

Introduction

• The last 50 years has seen a better understanding of the causes and treatments of cancer. Hence, the stigma, early detection and technology has improved the prognosis of cancer patients to an unprecedented level.

Cancer Statistics

• 553,400 Americans died of cancer 2001• 1.3 million new cases diagnosed• 1 in 4 deaths from cancer• Early detection/improvements in technology have

improved prognosis for many

• What do you think are the contributing factors to the incidence of cancer in the U.S. today?

Healthy Cells• Cells represent the

smallest, functional unit of our existence which contains cytoplasm and a nucleus (i.e. metabolism, reproduction, day to day functions)

• Cells have a specialized function depending on their location in the body.

• Cells grow, replicate and repair body organs.

• The genetic material (DNA/RNA) and your immune system regulate this process.

Different Types of Cells

• Blood cells• Muscle cells (smooth,

striated, cardiac)• Nerve cells• Bone cells

• Cartilage cells• Liver (hepa) cells

Define Cancer

• Cancer is a term used to describe a large group of diseases that are characterized by a cellular malfunction. Healthy cells are programmed to “know what to do and when to do it”. Cancerous cells do not have this programming and therefore grow and replicate out of control. They also serve no physiological function. These cells are now termed a neoplasm.

This neoplasmic mass often forms a clumping of cells known as a tumor.

Tumors

• Benign Tumors (noncancerous)

• Enclosed in a fibrous shell or capsule.

• Take up space• Concerned if they

interfere with surrounding tissues or vessels or impede the function of the body.

• Malignant Tumors (cancerous)

• Not usually contained – metastasis

• Invade and emit clawlike protrusions that disrupt the RNA and DNA of normal cells (these cancerous cells act like a virus).

Risk Factors (multi-factorial(

• Exposure to Cancer-causing agents• Cellular Mutations (what agents cause this?

Environment & Lifestyle agents)• Genetics & Hormone exposure (i.e. breast

cancer)• Occupation and Environment Factors• Social and Psychological Factors• Chemicals in Food• Viral (i.e. herpes, HPV, mononucleosis) create

an opportunistic environment• Medical Factors

Types of Cancer• Classifications of Cancer

– Carcinomas

– Sarcomas

– Lymphomas

– Leukemias

• Lung Cancer– Killed 164,000 in 2000

– Prevention-researchers theorize: 90% of all lung cancers could be avoided by not smoking

Gas Exchange in Your Lungs

Lung and Bronchus Cancer (Invasive), 1975-2002 (CDC(

Lung and Bronchus Cancer for U.S. Males, 1992-2002

Lung and Bronchus Cancer for U.S. Females, 1992-2002

Ten Leading Causes of Death for Males, 2002 (CDC(

Ten Leading Causes of Death for Females, 2002 (CDC(

An Overview of Cancer

• Variations in Rates– Rates have large variations among populations

– 444.6 per 100,000 African Americans

– 402.1 per 100,000 Whites

– 272.4 per 100,000 Hispanics

– 279.3 per 100,000 Asian Pacific Islanders

– 152.8 per 100,000 Native Americans

An Overview of Cancer

• What is Cancer?– Uncontrolled growth and spread of abnormal cells

– Neoplasms

– Malignant tumors

– Benign tumors

An Overview of Cancer

• Cellular Change/Mutation Theories– Spontaneous errors

– External agents

– Oncogenes

• Risks for Cancer-Lifestyle– Smoking among greatest

– Nutrition/exercise

Factors Believed to Contribute to Global Causes of Cancer

Figure 13.1

What Causes Cancer?

• Biological Factors– Genetic predisposition

– Reproductive and hormonal risks

What Causes Cancer?

• Occupational and Environmental Factors– Asbestos, nickel, chromate

– Radioactive substances

• Social and Psychological Factors– Stress

– Decrease negative emotions

What Causes Cancer?• Chemicals in Food

– Sodium nitrate

– Clostridium botulism

• Viral Factors– Herpes-related virus and human papillomavirus

• Medical Factors– Diethylstibestrol (DES)

– Chemotherapy

Table 13.1

Types of Cancer

• Breast Cancer– One in 8 women

– Risk increases with age

– Risk factors supported by research

– Prevention (self-exam and mammography)

– See figure 13.3 for self-examination procedure

– Treatment

Types of Cancer

• Colon and Rectum Cancer– 3rd most common in men and women

– 135,400 in 2001 diagnosed

– Warning signals, e.g. blood in the stool, rectal bleeding

• Prostate Cancer– Most common in males today

– 189,000 new cases will be diagnosed in 2002

– Estimated 30,200 men will die

Types of Cancer

• Skin Cancer: Sun Bathers Beware– 1.3 million cases of skin cancer

– Treatable: basal or squamous

– Virulent: malignant melanoma

– ABCD rule about melanoma

• What are some ideas about the use of sunscreen?

Types of Cancer

• Testicular Cancer– Ages 17-34 at greatest risk

– Cause is unknown

– Undescended testicles present a great risk

– How and when should men examine their testicles?(see Figure 13.4)

Types of Cancer

• Ovarian Cancer– 4th leading cause of death in young women

– Enlargement of abdomen common sign

– Prevention: annual pelvic exams

• Endometrium (Uterine) Cancer– Pap test for early detection– Risk: early onset of intercourse

– Warning: abnormal bleeding

Types of Cancer

• Cancer of the Pancreas– “Silent” disease

– 29,700 cases in 2002

– Only 4% survive

– Contributors: inflammation, diabetes, high-fat diet

Types of Cancer

• Leukemia– Cancer of blood-forming tissues

– Leads to the creation of immature white blood cells

– Symptoms: fatigue / paleness / weight loss

– Can be acute or chronic

Facing Cancer

• Detecting Cancer– Magnetic Resonance Imaging (MRI)

– Computerized Axial Tomography scanning (CAT scan)

– Prostatic ultrasound (rectal probe)

– Self-exam and check-ups

Table 13.3

Facing Cancer

• New Hope in Cancer Treatments– Surgery to remove tumor

– Chemotherapy

– Researching genes and cell mutations

Facing Cancer

• Talking with Your Doctor about Cancer– Ask questions about type, treatment, clinical trials

– Ask about surgery

– Ask why one treatment is preferred

– Get all your options

Facing Cancer

• Life After Cancer– Laws reduce insurance discrimination

– Less isolation

– Assistance is available

– Support groups