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Cancer. What is Cancer. Our bodies are made of cells, which grow, work, reproduce and die Genes on the DNA control when cells grow, work, reproduce and die Normally, cells obey these instructions Occasionally, these instructions get mixed up, and cells will divide unnecessarily
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What is Cancer • Our bodies are made of cells, which grow, work, reproduce and die • Genes on the DNA control when cells grow, work, reproduce and die • Normally, cells obey these instructions • Occasionally, these instructions get mixed up, and cells will divide unnecessarily • Some of these cells can form lumps or tumours, or even spread throughout the body
How does cancer develop? • A mix up in the instructions or a mutation in a piece of DNA that controls the cell cycle, could develop into cancer • Because you have two copies of theses instructions (from your mom and dad), it often takes a couple of mutations for cancer to start • As mutations accumulate, there is less and less control on the cell cycle
Some agents that causes mutations? Theses are referred to as Carcinogenic or cancer causing: Ultraviolet light Cosmic Rays X Rays Chemicals (eg. Eg. Benzo-a-pyrene - found in coal tar - found in cigarette smoke - found in overcooked meats)
Tumours • Once a cell starts to divide uncontrollably and forms a mass, this mass of cells is called a tumour • Tumours can be either benign (non-cancerous) or malignant (cancerous). • Benign tumour cells stay in one place in the body and are not usually life-threatening. • Malignant tumour cells are able to invade nearby tissues and spread to other parts of the body. • Cancer cells that spread to other parts of the body are called metastases.
Lung Cancer • Lung cancer starts in the cells of the lung Causes • Smoking tobacco is the main cause • exposure to asbestos • exposure to radon gas • having had lung cancer before • family history of lung cancer • air pollution
Colorectal Cancer • Most colorectal cancers start in the cells that line the inside of the colon or the rectum. Risk Factors • age – particularly after 50 • alcohol consumption • smoking • physical inactivity • obesity • high-fat diet – may be missing out on important vitamins, fibre and antioxidants (natural cancer fighting compounds)
Skin Cancer • Caused by Ultaviolet radiation (UVA and UVB rays) • UVA rays penetrate the layers of the skin more deeply compared to UVB rays but both can be damaging to the skin • UVB rays cause the burning Sensation while UVA rays age your skin
Finding and Beating Cancer • Most cancers take years to develop so they are detected later in life • To reduce your risk: • Quit soking • Protect your skin from the sun • Do self-examination for early detection as in breast cancer • Exercise regularily • Eat plenty of fruits and veggies
Detecting Cancer • Moles – an early indicator of cancer
Diagnostic techniques • X-rays – useful in detecting cancers that form in some internal body parts • Mammogram – type of x-ray used to detect breat cancer
Confirming Cancer – doing a biopsy • A biopsy is a surgery where a small portion of the suspected tumour is removed and the cells are compared to normal cells of that area.
Treating Cancer • Radiation Therapy – ionizing radiation is used to kill the cells of the cancer • Chemotherapy – uses chemicals to stop cancer cells from dividing • Surgery – remove the tumour from the body
Cancer Myths??? Artificial Sweeteners? • No conclusive evidence Fluoridated Water • No association found/no increased risk Heterocyclic amines in cooked meat • Increase in cancer risk
Cancer Myths??? Abortions • No increased risk found Oral Contraceptives • Reduced risk of ovarian cancer, increased risk of breast, liver and cervical cancers Breast Implants • No association found
Cancer Myths??? Cell Phones • No conclusive evidence found, but research is recommended to continue Antiperspirants/Deodorants • No evidence of link to breast cancer (conflicting evidence) Microwave Ovens • No evidence of link to cancer
Cancer Myths??? Cigarette Smoke • Duh! Second Hand Smoke • Direct link. Over 60 carcinogens found in second hand smoke Third Hand Smoke (cigarette smoke residues found on furniture/carpets etc) • Emerging evidence is suggesting a health risk, which may include cancer