1. Cancer notes

2. Cancer Cancer - Malignant, spreading tumor Tumor – any swelling
Oncology – study of tumors and their problems
Neoplasm – abnormal tissue growth resulting in rapid cellular proliferation which continues after growth of normal tissue has stopped or slowed
Benign or Malignant

3. Neoplasms Benign – not inclined to spread or get worse
Less dangerous than malignant tumors but can compress surrounding tissues and impair their functions as a result of enlargement

4. Neoplasms Malignant – able to spread and become worse
Cells are more spherical because they don’t adhere to surrounding normal cells
More embryonic, less mature, than normal tissue
Invasive, ability to squeeze into spaces and enter surrounding tissues
Secrete enzymes that cut paths through healthy tissue
Grow irregularly, sending processes in every direction
Ability to dislodge, enter blood vessels, lymphatic vessels or body cavities
Travel to distant sites, attach and invade tissues

5. Genetics of Cancer Mutations of genes within somatic cells
Occurs during DNA replication
Radiation, chemicals, toxins & viruses cause mutations by damaging or altering DNA
Usually develop in tissues that undergo frequent cell division

6. Genetics of Cancer
Neoplasm can become cancerous when cell’s structure and functions are changed
Increase ability of cancer cells to invade and destroy surrounding tissue
Metastasize
Resistant to drug treatments

7. Genetics of Cancer Prevention of development in cancer cells:
DNA repair enzymes detect and correct errors during replication
Self-destruction mechanism destroys cells with abnormal DNA (Apoptosis)

8. Genetics of Cancer Proto-oncogenes – promote cell division
Oncogenes – abnormal regulatory genes, increases rate of cell division
Tumor suppressor genes – normal genes that slow down or stop cell division

9. Cancer
Metastasis – process by which cancer cells spread to distant sites
Secrete substances that cause blood vessels to grow into the tumor and supply oxygen and nutrients.

10. Types of Cancer Carcinoma – cancer of epithelial tissue
Basal cell & Squamous cell carcinomas
Adenocarcinoma – gladular epithelium
Breast cancer
Sarcoma – connective tissue
Osteosarcoma – bones
Chondrosarcoma - cartilage

11. Cancer Therapy Concentrates on confining and killing malignant cells
X-rays, lasers, surgical removal, drugs
Problem: Some cancers can’t be removed completely by surgery or killed
Affects normal tissues
Newer drugs prevent blood vessel development
Anticancer therapies – cells that can recognize tumor cells and destroy them

12. Chemotherapy
Any treatment involving chemical agents to stop cancer cells from growing
Eliminate cancer cells at sites great distances from original cancer
More than half receive chemotherapy
Administered through a vein, injected into a body cavity or delivered orally as a pill
Destroys cancer cells but does not distinguish between cancer & healthy cells
Eliminates fast growing cells: cancer, hair & blood cells

13. Skin Cancer Most common type of cancer
Caused by UV rays, chemicals, x-rays, inflammation, inherited
Amount of protective melanin affects skin cancer
Fair-skinned = gen. predisposed to develop skin cancer
Individuals over 50 yrs = increased risk

14. Skin Cancer Three major types of skin cancer are: Basal cell carcinoma
Squamous cell carcinoma
Melanoma

15. No. 1 Basal Cell Carcinoma
Least malignant and
most common skin cancer
Stratum basale cells proliferate and invade the dermis and hypodermis
Slow growing and do not often metastasize
Can be cured by surgical excision in 99% of the cases

16. Squamous Cell Carcinoma
Arises from keratinocytes of
stratum spinosum
Arise most often on scalp, ears, and lower lip; bleeding can occur
Grows rapidly and metastasizes if not removed; if travels to lymph nodes, can be fatal
Can be treated by radiation
therapy or removed surgically

17. Melanoma Cancer of melanocytes is the most dangerous
type of skin cancer because it is:
Highly metastatic
Resistant to chemotherapy
77% of skin cancer deaths in U.S.
40% develop in preexisting moles

18. Melanoma Melanomas have the following characteristics (ABCDE rule)
A: Asymmetry; the two sides of the pigmented area do not match
B: Border is irregular and exhibits indentations
C: Color (pigmented area) is not uniform: black, brown, tan, and sometimes red or blue
D: Diameter is larger than 6 mm (size of a pencil eraser)
E: Evolving (lesions change over time) Change size, shape, elevation or color, bleed, crust or become tender

19. Melanoma
Treated by wide surgical excision accompanied by immunotherapy
Chance of survival is poor if the lesion is over 4 mm thick

20. UVA vs UVB
The sun has 2 types of UV (ultraviolet), rays: 1. UVA 2. UVB

21. UVA UVA - long-wave solar rays of 320-400 nm.
Goes through windows, light clothing and even windshields
Responsible for aging
Less likely than UVB to cause sunburn
UVA penetrates the skin more deeply, causing wrinkling and leathering of the skin.
UVA may also directly induce some skin cancers, including melanomas.

22. UVB Short-wave solar rays of 290-320 nm
More potent than UVA in producing sunburn.
Main cause of skin cancers.
The"tanning ray", UVB stimulate the melanocyte cell, producing a suntan as a defense against UV radiation

23. Skin Cancer prevention
NOT FOOLPROOF BUT IMPORTANT…. wear SUNCREEN!