Cancer Ppt 2008


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Cancer Ppt 2008

  1. 1. Cancer
  2. 2. Introduction <ul><li>A group of more than 200 diseases characterized by uncontrolled and unregulated growth of cells </li></ul><ul><li>In NZ 14,808 new cases of cancer </li></ul><ul><li>1 in 3 men and 1 in 4 women will be affected by age 75yrs </li></ul><ul><li>Most common cause of death in NZ (29% of deaths overall) </li></ul>
  3. 3. Cancer <ul><li>Most common cancers causing death in males are lung, prostate and colorectal </li></ul><ul><li>Most common cancers causing death in females are breast, lung & colorectal </li></ul><ul><li>Cancer rates for Maori & non Maori are similar but mortality rates are 51% (males) and 78%(females) higher for Maori </li></ul>
  4. 4. <ul><li>5-year survival rate is now 62% for those who are disease free, in remission, or under treatment </li></ul><ul><li>5-year survival rates do not include the number of people who are “cured” of cancer </li></ul>
  5. 5. Defect in Cellular Proliferation (process by which cells divide & reproduce) <ul><li>Cancer cells are characterized by the loss of contact inhibition – have no regard for cellular boundaries </li></ul><ul><ul><li>Grow on top of one another and on top of or between normal cells </li></ul></ul><ul><li>Cancer cells divide indiscriminately and haphazardly – sometimes they produce more than 2 cells at the time of mitosis </li></ul>
  6. 6. Defect in Cell Proliferation <ul><li>In most situations, cancer cells multiply at the same rate as the normal cells from which they originate </li></ul><ul><li>The difference is that proliferation of the cancer cells is indiscriminate and continuous </li></ul><ul><li>Because of this there is continuous growth of a tumour mass </li></ul>
  7. 7. Defect in Cellular Differentiation <ul><li>Cellular differentiation (the development of specific & distinctive features in cells) is normally an orderly process </li></ul><ul><li>Protooncogenes </li></ul><ul><li>Normal cellular genes that are important regulators on normal cellular processes </li></ul><ul><li>Mutations that alter their expression can activate them to act as oncogenes (tumour-inducing) </li></ul>
  8. 8. Neoplasms <ul><li>Characterised as: </li></ul><ul><li>Benign neoplasms </li></ul><ul><li>Malignant neoplasms </li></ul><ul><li>Major difference between malignant & benign neoplasms is the ability of malignant tumour cells to invade and metastasize </li></ul>
  9. 9. Benign Neoplasms <ul><ul><ul><li>Well differentiated (specific & distinctive features of cells are well developed). </li></ul></ul></ul><ul><ul><ul><li>Cells resemble the cells of tissue of origin. </li></ul></ul></ul><ul><ul><ul><li>Well-defined fibrous capsule </li></ul></ul></ul><ul><ul><ul><li>Characterized by slow, progressive rate of growth. </li></ul></ul></ul><ul><ul><ul><li>Tumours grow by expansion </li></ul></ul></ul><ul><ul><ul><li>Metastases absent </li></ul></ul></ul><ul><ul><ul><li>Recurrence unusual </li></ul></ul></ul><ul><ul><ul><li>Do not usually cause death unless they interfere with vital functions because of location e.g.. Benign cranial tumour compressing brain structures </li></ul></ul></ul>
  10. 10. Malignant Neoplasms <ul><ul><ul><li>Tend to grow rapidly, spread widely, & kill regardless of original location </li></ul></ul></ul><ul><ul><ul><li>Able to metastasize </li></ul></ul></ul><ul><ul><ul><li>Because of rapid growth, they compress blood vessels & outgrow their blood supply causing ischaemia & tissue necrosis </li></ul></ul></ul><ul><ul><ul><li>Rob normal tissues of essential nutrients </li></ul></ul></ul><ul><ul><ul><li>Liberate enzymes & toxins that destroy normal & tumour tissue </li></ul></ul></ul><ul><ul><ul><li>Infiltrative and expansive </li></ul></ul></ul><ul><ul><ul><li>Frequent recurrence </li></ul></ul></ul><ul><ul><ul><li>Moderate to marked vascularity </li></ul></ul></ul><ul><ul><ul><li>Rarely encapsulated </li></ul></ul></ul><ul><ul><ul><li>Cells abnormal; become more unlike parent cells </li></ul></ul></ul>
  11. 11. Effects on Body Function with Cancer Growth <ul><li>Altered function of involved tissue </li></ul><ul><li>Bleeding & haemorrhage </li></ul><ul><li>Ulceration, necrosis & infection of tumour area </li></ul><ul><li>Obstruction of hollow organs or pathways </li></ul><ul><li>Effusion in serous cavities </li></ul><ul><li>Increased risk of vascular thrombosis </li></ul><ul><li>Anaemia </li></ul><ul><li>Bone destruction </li></ul>
  12. 12. Effects (cont.) <ul><li>Hypercalcaemia </li></ul><ul><li>Pain </li></ul><ul><li>Cachexia – weight loss & wasting of body fat & lean protein </li></ul><ul><li>Inappropriate hormone production (e.g. ADH or ACTH secretion by cancers such as bronchogenic carcinaoma) </li></ul>
  13. 13. Cachexia
  14. 14. Advanced Breast Cancer
  15. 15. Cancer of Kidney
  16. 16. Ascites – Liver Cancer
  17. 17. Development of Cancer <ul><li>Carcinogens – cancer-causing agents capable of producing cellular alterations </li></ul><ul><li>Can be chemical, environmental, immunologic, viral, or spontaneous in origin </li></ul><ul><li>Some genetic abnormalities increase the susceptibility of individuals to certain cancers </li></ul><ul><li>Hereditary predisposition in approx 50 types of cancers e.g. breast cancer </li></ul>
  18. 18. Process of Cancer Development Fig. 15-3
  19. 19. Metastasis <ul><li>The spread of cancer from the initial or primary site to a distant site </li></ul><ul><li>Some metastasize early e.g. pre-menopausal breast cancer </li></ul><ul><li>Others spread regionally and rarely metastasize e.g.. BCC of skin </li></ul><ul><li>Certain cancers have an affinity for a particular tissue or organ as a site of metastasis, others are unpredictable e.g. melanoma </li></ul>
  20. 20. Metastasis (cont.) <ul><li>Certain cancers (‘seed’), such as ovarian cancer, require a particular site for proliferation (‘soil’) </li></ul><ul><li>Most frequent sites for metastases are lungs, brain, , bone, liver & adrenals </li></ul>
  21. 21. Metastasis <ul><ul><ul><li>Metastasis process begins with rapid growth of primary tumour </li></ul></ul></ul><ul><ul><ul><ul><li>Development of its own blood supply is critical for survival </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Tumour angiogenesis is formation of blood vessels within the tumour </li></ul></ul></ul></ul>
  22. 22. Melanoma Metastases
  23. 23. Progression of Cancer Metatases
  24. 25. Role of Immune System <ul><li>Immune response is to reject or destroy cancer cells if perceived as non-self </li></ul><ul><ul><li>May be inadequate as cancer cells arise from normal human cells </li></ul></ul><ul><li>Some cancer cells have changes on their surface antigens </li></ul><ul><ul><li>Tumor-associated antigens (TAAs) </li></ul></ul>
  25. 26. Role of Immune System <ul><ul><li>Response to TAAs is termed immunologic surveillance </li></ul></ul><ul><ul><ul><li>Lymphocytes continually check cell surfaces and detect and destroy cells with abnormalities </li></ul></ul></ul><ul><ul><ul><li>Involves cytotoxic T cell, natural killer cells, macrophages, and B lymphocytes </li></ul></ul></ul>
  26. 27. Role of Immune System <ul><li>Escape mechanisms by which cancer cells evade immune system </li></ul><ul><ul><li>Suppression of factors that stimulate T cells </li></ul></ul><ul><ul><li>Weak surface antigens allow cancer cells to “sneak through” surveillance </li></ul></ul>
  27. 28. Role of Immune System <ul><ul><li>Development of tolerance of immune system </li></ul></ul><ul><ul><li>Suppression of immune response to products secreted by cancer cells </li></ul></ul><ul><ul><li>Induction of suppressor T cells </li></ul></ul><ul><ul><li>Blocking antibodies that bind TAAs </li></ul></ul>
  28. 29. Classification of Cancer <ul><li>Anatomic Site Classification </li></ul><ul><ul><li>Identified by </li></ul></ul><ul><ul><ul><li>tissue origin </li></ul></ul></ul><ul><ul><ul><li>anatomic site </li></ul></ul></ul><ul><ul><ul><li>behaviour of the tumour </li></ul></ul></ul>
  29. 30. Classification of Cancer <ul><li>Anatomic Site Classification </li></ul><ul><ul><li>Carcinomas originate from embryonal ectoderm and endoderm </li></ul></ul><ul><ul><li>Sarcomas originate from embryonic mesoderm </li></ul></ul><ul><ul><li>Lymphomas and leukaemias originate from hepatopoietic system </li></ul></ul>
  30. 31. Classification of Cancer <ul><li>Histologic Analysis Classification </li></ul><ul><ul><li>Appearance of cells and degree of differentiation are evaluated </li></ul></ul><ul><ul><ul><li>Grade 1: Cells differ slightly from normal cells and are well differentiated </li></ul></ul></ul><ul><ul><ul><li>Grade 2: Cells more abnormal and moderately differentiated </li></ul></ul></ul>
  31. 32. Classification of Cancer <ul><ul><ul><li>Grade 3: Cells very abnormal and poorly differentiated </li></ul></ul></ul><ul><ul><ul><li>Grade 4: Cells immature and primitive and undifferentiated; cell of origin difficult to determine </li></ul></ul></ul>
  32. 33. Classification of Cancer <ul><li>Clinical Staging </li></ul><ul><ul><li>0: cancer in situ </li></ul></ul><ul><ul><li>1: tumor limited to tissue of origin </li></ul></ul><ul><ul><li>2: limited local spread </li></ul></ul><ul><ul><li>3: extensive local and regional spread </li></ul></ul><ul><ul><li>4: metastasis </li></ul></ul>
  33. 34. Classification of Cancer <ul><li>TNM Classification </li></ul><ul><ul><li>Tumor size </li></ul></ul><ul><ul><li>Spread to lymph nodes </li></ul></ul><ul><ul><li>Metastasis </li></ul></ul>
  34. 35. TNM Classification System <ul><li>T (tumour) </li></ul><ul><li>Tx Tumour unable to be adequately assessed </li></ul><ul><li>T0 No evidence of primary tumour </li></ul><ul><li>Tis Carcinoma in situ </li></ul><ul><li>T1-4 Progressive increase in tumour size or involvement </li></ul>
  35. 36. TNM Classification System <ul><li>N (nodes ) </li></ul><ul><li>Nx Regional lymph nodes cannot be assessed </li></ul><ul><li>N0 No evidence of regional node metastasis </li></ul><ul><li>N1-3 Increasing involvement of regional lymph nodes </li></ul>
  36. 37. TNM Classification System <ul><li>M (metastasis) </li></ul><ul><li>Mx Not assessed </li></ul><ul><li>M0 No distant metastasis </li></ul><ul><li>M1 Distant metastasis present, specify sites </li></ul>
  37. 38. Prevention and Detection of Cancer <ul><li>Reduce or avoid exposure to known or suspected carcinogens </li></ul><ul><li>Eat balanced diet </li></ul><ul><li>Exercise regularly </li></ul><ul><li>Adequate rest </li></ul><ul><li>Health examination on a regular basis </li></ul>
  38. 39. Prevention and Detection of Cancer <ul><li>Eliminate, reduce, or change perceptions of stressors and enhance ability to cope </li></ul><ul><li>Enjoy consistent periods of relaxation and leisure </li></ul><ul><li>Know 7 warning signs of cancer </li></ul><ul><li>Self-examination </li></ul><ul><li>Seek medical care if cancer is suspected </li></ul>
  39. 40. Early Warning Signs of Cancer <ul><li>Change in bowel or bladder habits </li></ul><ul><li>A sore that does not heal </li></ul><ul><li>Unusual bleeding or discharge </li></ul><ul><li>Thickening or lump in breast or elsewhere </li></ul><ul><li>Indigestion or difficulty in swallowing </li></ul><ul><li>Obvious change in mole or wart </li></ul><ul><li>Nagging cough or hoarseness </li></ul>