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• There 2 types of cancers – carcinoma – cancer of cells that cover the outside and inside surface of the body

  Sarcoma – cancer of cells in supportive tissues – bones and muscles

  All are malignant tumors
• There are 2 types of tumor – benign and malignant

  Benign – grow slowly, expand, well differentiated and are local.

  Malignant – grow rapidly, infiltrate, poorly differentiated and metastasize.
• Teratoma – contains mixed cells and found in reproductive tract. Has oil, muscle, fat, hair and bone
• Oncogenesis – when normal cells become cancer cells.
• Cancer cell division - normal cell division is controlled. Cancer cell division has no control.

  This is because there is no tumor suppressor proteins, Ignore normal processes, make own hormones for control.
• There are 2 oncogenesis models – conventional and adaptive

  Conventional model – as we age, the risk of cancer increases. This is because mutations are allowed to form which causes changes that stop making tumor suppressor proteins and increase oncogenes
• Adaptive oncogenesis model – if healthy cells decreases because of aging, cancer causing mutations can occur which allows the cell to easily adapt, making the cell get picked for further growth leading to cancer
• Invasion – when cancer cells spread from one part to another in the body

  Metastasis – tumor cells are spread through the body by circulatory systems to organs like lungs which can form bigger tumors.
• Tumor angiogenesis– tumors need oxygen and nutrients to grow. The bigger the tumor gets, the harder for it to get oxygen. The tumor then releases signals that make the blood vessels grow towards the mass.

  The centre of the tumor is called a necrotic core.
• Skin cancer – melanocyte tumors.

  Nevus is benign melanocyte tumor

  Melanoma is malignant melanocyte tumor

  Difference between common mole and melanoma is asymmetry, colour, border and diameter.
• Basal cell carcinoma – grows very slowly. Treatable. Starts growing in the basal layer of epidermis. Found in areas exposed to sun (head, neck, face, arms). Common in fair skin people.

  Squamous cell carcinoma – more aggressive than basal. Treatable. Can appear as red skin patches. Can spread to other parts of body. Found in fair skinned people.

  Melanoma – deadly. Starts in melanocytes. Starts as mole then turns cancerous. Spreads fast. Found in fair skinned people.
• Lung cancer - due to tobacco smoking. Found in any part of lung. Found in epithelial cells lining bronchi and bronchioles and sometimes from pleura.

  2 types of lung cancer – small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC)
• There are 3 types of blood cancers – leukemia, lymphoma and myeloma

  Leukemia – found in blood and bone marrow. Due to a lot of abnormal WBC. WBC cant fight infection. Impairs RBC and platelet production from bone marrow.

  Lymphoma – affects lymphatic system. Lymphoma can multiply and be stored in lymph nodes. Impairs immune system as it cant fight infection.

  Myeloma – targets plasma cells. Stops normal antibody production. Immune system is weakened and body is vulnerable to infections.
• Breast cancer – cancer cells are formed in breast. Increased risk in females with BRCA 1 and BRCA 2 mutations. Mutation can be inherited. Most common type of cancer.
• Breast cancer testing – physical exam and history, clincal breast exam, biopsy, MRI and ultrasound
• Prostate cancer – common male cancer. Spreads to pelvic bone by lymphatic and circulatory system. Age, hereditary, race and diet are risk factors.
• Cancer causes – physical (radiation), chemical (mutagens), biological (viral/genetic)
• Biological – viral or bacterial. Viral uses complex mutation mechanisms. Example is human papilloma virus and Hep B virus.

  Bacterial is heliobacter pylori – stomach cancer.
• Chemical mutagens – foreign molecules bind to DNA leading to mutation. Examples are benzopyrene, vinyl chloride, aflatoxin.
• Physical mutagens – mutates DNA by radiation.

  Ionizing radiation – breaks correct DNA sequence. (x ray)

  Ultraviolet radiation – DNA sections remains stuck together. Leads to misread DNA

  Mineral fibers – direct DNA damage because of mutagen size. Leads to carcinogenic mutation.
• Polyp/Papilloma - benign from surface epithelium

  Adenoma – from glandular organs. Epithelial benign tumor

  Carcinoma – malignant. From surface, glandular or parenchymal epithelium.

  Sarcoma – malignant. Any other than surface, glandular and parenchymal

  Leukemia – blood cells neoplasm