Transcript You Light Up My Life

Genes and Disease: Cancer
Chapter 23
Tumors (Neoplasms)
• Masses that show abnormal growth
• Benign tumors
– Grow slowly
– Remain in place
– Moles are example
• Malignant tumors (cancer)
Cancer Characteristics
• Cells lack normal contact inhibition
• Weakened capacity for adhesion
– Metastasis
• Some kinds produce HCG
• Some produce angiogenin, which
encourages blood vessel growth
Metastasis
Cells
break
away
Enter
blood
vessel
Emerge
in new
tissue
Proto-Oncogenes
• Normal genes that regulate cell growth
and development
• Encode growth factors, proteins that
regulate cell adhesion, and protein
signals for cell division
• If altered, may be converted to an
oncogene
Oncogenes & TumorSuppressor Genes
• Oncogene does not act alone to cause
cancer
• Cancer usually requires mutations in
several genes, including at least one
tumor-suppressor gene
• p53 is a tumor-suppressor gene that is
mutated or absent in about half of
cancers
Other Routes to Cancer
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Heredity
Viruses
Radiation
Breakdown in
immunity
• Environmental
chemicals
– Pesticides
– Industrial
chemicals
– Hydrocarbons
in smoke
– Plant and fungal
carcinogens
Warning Signs of Cancer
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Change in bowel or bladder habits
A sore that does not heal
Unusual bleeding
Thickening or lump
Indigestion, difficulty swallowing
Obvious change in wart or mole
Nagging cough or hoarseness
Diagnosing Cancer
• Blood tests for tumor markers
• Medical imaging
• Biopsy
• DNA probe
Treating Cancer
• Chemotherapy
• Monoclonal antibodies
• Immunotherapy
Interferons
Cancer vaccines
Interleukins
Limiting Cancer Risk
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Avoid tobacco
Limit alcohol
Maintain desirable weight
Eat healthy diet
Be aware of potential chemical exposure
Protect skin from sunlight
If menopausal, consider risks of estrogen
Types of Cancer &
Their Origins
• Sarcoma (connective tissue)
• Carcinoma (epithelium)
• Adenocarcinoma (glandular tissue)
• Lymphoma (lymphoid tissue)
• Leukemia (blood-forming regions of
bone marrow)
Breast Cancer
1 in 9 women
Risk factors
Obesity
Late childbearing
Early puberty
Late menopause
Family history
Detection
Self examination
Mammogram
Treatment
Surgery
Drugs
Tamoxifen
Reproductive System Cancers
Uterine cancer
(endometrium,
cervix)
Pap smear
Ovarian cancer
Taxol
Testicular cancer
Self examination
Prostate cancer
Digital rectal exam
PSA blood test
Oral and Lung Cancers
Oral cancers
• Tobacco use
• Alcohol use
Lung cancers kill
more people than any
other cancers
Lung cancers
• Tobacco use
• Secondhand smoke
• Asbestos, industrial chemicals
Digestive System Cancers
• Stomach cancer
• Pancreatic cancer
• Liver cancer
• Colon cancer
Cancers of the Blood
and Lymphatic System
Lymphomas
• Non-Hodgkin lymphoma
• Hodgkin’s disease
• Burkitt lymphoma
Leukemias
• Stem cells overproduce
white blood cells
• Vincristine and vinblastine
Skin Cancer
• Most common of all cancers
• Basal cell carcinoma
• Squamous cell carcinoma
• Malignant melanoma
– Deadliest skin cancer
– Kills 5,600 per year in United States