Transcript What is Cancer? - McGraw

Chapter Twenty-two
Cancer: Understanding a
Complex Condition
© 2007 McGraw-Hill Higher Education. All rights reserved.
What is Cancer?
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A condition of uncontrolled growth of cells
Develops from a single cell that goes awry,
but a combination of events must occur
before the cell turns into a tumor
clonal growth: when the replication of cells
copy themselves in an uncontrolled manner
© 2007 McGraw-Hill Higher Education. All rights reserved.
Healthy Cell Growth
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Healthy cells have a complicated system of checks
and balances that control cell growth and division
Healthy cells divide when needed to replace cells
that have died or been sloughed off
A special protective mechanism exists for certain
cells called stem cells
Stem cells can become different cells and are
capable of dividing many times as well as selfdestructing if exposed to a toxin
© 2007 McGraw-Hill Higher Education. All rights reserved.
Cancer Cell Growth
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Cancer arises from a single cell that is mutated or
exposed to a carcinogen, a cancer causing
substance
An initiating event occurs as a result of an error in
duplication or in response to a carcinogen
An oncogene is a gene that drives a cell to grow
and divide regardless of signals from surrounding
cells
A tumor may form (mass of extra tissues) and
become either benign (slow growth) or malignant
(capable of spreading to surrounding tissues)
© 2007 McGraw-Hill Higher Education. All rights reserved.
Classifying Cancers
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Cancers are classified according to the tissue in which
they originate called the primary site
Tumors are graded on the basis of the degree to
which the tumor cells resemble healthy cells of the
same tissue type, from a low grade (grade I) to a high
grade (grade IV)
The stage of the disease is a description of how far
the cancer has spread
– Two systems of staging:
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5 categories (0 to stage 4 based on the cancer layers of
cells)
TNM (tumors, nodes, metastasis ratings from 0-4)
© 2007 McGraw-Hill Higher Education. All rights reserved.
Types of Cancer
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Four broad types of cancer are distinguished:
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Carcinomas (epithelial tissue, including the skin,
surface of body organs, outer portion of glands)
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Sarcomas (connective tissue such as bone, tendon,
cartilage, muscle, fat tissues)
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Leukemias
(blood and bone marrow or the lymphatic
system)
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Lymphomas (lymph nodes and glands)
© 2007 McGraw-Hill Higher Education. All rights reserved.
Risk Factors For Cancer
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Family History
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Lifestyle Factors
– Tobacco Use
– Dietary Patterns
– Overweight and
obesity
– Physical inactivity
– Alcohol consumption
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Environmental
Factors
– Ultraviolet Radiation
– Other forms of
radiation
– Chemical
carcinogens
– Infectious agents
© 2007 McGraw-Hill Higher Education. All rights reserved.
Common Cancers
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Lung Cancer
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Colon and Rectal Cancer
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3rd leading cause of death and the 3rd most commonly
diagnosed cancer
Breast Cancer
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Leading cause of death for men and women in the US
Second most diagnosed cancer
Second leading cause of cancer death in women
Prostate Cancer
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Second most common cause of cancer death in men
Most commonly diagnosed cancer for men
© 2007 McGraw-Hill Higher Education. All rights reserved.
Lung Cancer
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Risk Factors
– Smoking
– Environmental pollutants
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Symptoms
– Coughing
– Chest pain
– Difficulty breathing
© 2007 McGraw-Hill Higher Education. All rights reserved.
Lung Cancer
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Prevention
– Remove smoke element
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Treatment
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Surgery
Radiation
Chemotherapy
Medications
© 2007 McGraw-Hill Higher Education. All rights reserved.
Colon and Rectal Cancer
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Risk factors
– Genetic and dietary habits
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Warning signs
– Change in bowel movements
– Change in stool size or shape
– Pain in the abdomen or blood in the stool
© 2007 McGraw-Hill Higher Education. All rights reserved.
Colon and Rectal Cancer
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Prevention
– Removal of polyps, exercise, dietary
supplementation
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Early Detection
– Rectal exams, stool test, sigmoidoscopy,
colonoscopy
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Treatment
– Surgery, radiation, chemotherapy
© 2007 McGraw-Hill Higher Education. All rights reserved.
Breast Cancer
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Risk factors
– Early menstrual cycle for women
– Women with no children or having children later in life
– Hormone replacement therapy use
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Prevention
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Diet
Mammography
Activity levels
Pregnancy and breastfeeding decisions
Occupational hazards
New medications
Treatment
– Lumpectomy
– Drug therapy
– Chemotherapy/radiation treatments
© 2007 McGraw-Hill Higher Education. All rights reserved.
Prostate Cancer
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Risk factors
– Age, dietary fat intake, genetic link
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Symptoms during the advanced stage
– Associated with difficulty urinating or pain in the
pelvic region, or blood in the urine
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Early Detection
– PSA screenings, digital rectal exam
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Treatment
– Surgery, radiation, hormonal medications,
chemotherapy
© 2007 McGraw-Hill Higher Education. All rights reserved.
Cancers of the Female
Reproductive System
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Cancer can develop throughout the female
reproductive system but occur more
frequently in the following areas:
Cervix
 Uterus
 Ovaries
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© 2007 McGraw-Hill Higher Education. All rights reserved.
Cervical Cancer
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Risk factors
– HPV infection (cervical dysplasia)
– Smoking and socioeconomic factors
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Prevention
– Sexual abstinence
– Pap tests
– Careful selection of sexual partners
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Treatment
– Surgery (minor or major)
– Radiation/chemotherapy
© 2007 McGraw-Hill Higher Education. All rights reserved.
Uterine Cancer
[Endometrial Cancer]
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Risk Factors
– Early menarche, late menopause, lack of ovulation, never
having given birth, ERT, use of tamoxifen, and also in
diabetics, obese, and hypertensive women
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Prevention
– Minimize high levels of estrogen and regular physician care
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Treatment
– Surgery, radiation, chemotherapy, hormone treatment
© 2007 McGraw-Hill Higher Education. All rights reserved.
Ovarian Cancer
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The leading gynecological cause of cancer death and
the fourth overall cause of cancer in women
– Prevention
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Similar to what is recommended for breast cancer
Prophylactic oophorectomy
– Early Detection
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Referred as the “silent cancer”
– Annual pelvic exams
– Genetic screenings
– Treatment
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Surgery
Chemotherapy
Drug therapy
© 2007 McGraw-Hill Higher Education. All rights reserved.
Skin Cancer
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There are 3 types of skin cancer that exist:
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Basal cell cancer (lesions and sores)
Squamous cell cancer (raised bumps and sores)
Melanoma (spreads quickly)
Risk factors
– Severe sunburn during childhood, chronic sun exposure
during young adulthood
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Prevention
– Reduce exposure to sun’s rays, use sunscreens
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Early Detection
– American Cancer Society guidelines (next slide)
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Treatment
– Surgery, chemotherapy, interleukin-2
© 2007 McGraw-Hill Higher Education. All rights reserved.
American Cancer Society Guidelines
(Figure 22.3)
Asymmetry
Border irregularity
Color change
Diameter greater than 6mm
© 2007 McGraw-Hill Higher Education. All rights reserved.
Testicular Cancer
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The most common cancer for men aged
15-35 years
– Risk factors
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Family history, environmental factors
– Prevention
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Self exams
– Early Detection
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Observations and self exams
– Treatment
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Surgery, chemotherapy, radiation
© 2007 McGraw-Hill Higher Education. All rights reserved.
Oral Cancer
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Cancers that develop in the mouth or the pharynx
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Risk factors include:
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Early signs include:
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Cigarettes, cigars, pipes or smokeless tobacco
High levels of alcohol consumption
Persistent sore in the mouth
Lump or bump that won’t heal
Patch of white or red along the gums or cheeks
Treatment
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Surgery
Chemotherapy
Radiation
© 2007 McGraw-Hill Higher Education. All rights reserved.
Leukemia
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Group of cancers that originate in the bone marrow or
other parts of the body where white blood cells form
Results in the overproduction of one type of white
blood cell which leads to increased risk of infection,
anemia, and bleeding
Risk factors are:
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Cigarette smoking and exposure to chemicals
Ionizing radiation exposure
Infection with a virus
Treatment
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Chemotherapy
Possible bone marrow transplant
© 2007 McGraw-Hill Higher Education. All rights reserved.
Cancer Treatments
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Surgery (removal of tissue)
Chemotherapy (drug treatment which interfere with
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Radiation (alters DNA which can destroy cancer cells
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Biological Therapies
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rapid cell division)
with minimal damage to surrounding tissues)
– Immunotherapy medications
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Bone Marrow Transplantation
Gene Therapy and Genetic Testing
© 2007 McGraw-Hill Higher Education. All rights reserved.
Chapter Twenty-two
Cancer: Understanding a
Complex Condition
© 2007 McGraw-Hill Higher Education. All rights reserved.