NURS 212: Week 15 - Cancer

• Cancer


  A disease of disordered growth and differentiation
• Cancer


  Associated with altered expression of cellular genes that normally regulate cell proliferation and differentiation
• Risk factors for cancer


  • Increasing age
  • Tobacco use
  • Nutrition
  • UV radiation
  • Certain viruses
  • Environmental toxins
• Benign tumors


  • Usually well-differentiated cells, encapsulated and do not spread
  • Can cause health problems due to location or size of the tumor
• Malignant tumors


  • More rapid growth, loss of differentiation, loss of normal tissue organization (anaplasia)
  • Can spread to other tissues (metastasis)
• Neoplasm


  New growth
• Dysplasia


  Not cancer
• Anaplastic cells


  Loss of normal tissue architecture is cancer
• Carcinoma in situ (CIS)


  Preinvasive epithelial malignant tumors of glandular or epithelial origin that have not broken through the basement membrane or invaded the surrounding stroma - readily treatable
• Differences between benign and malignant tumors


  • Benign: Grow slowly, well-defined capsule, not invasive, well differentiated, low mitotic index, do not metastasize
  • Malignant: Grow rapidly, not encapsulated, invasive, poorly differentiated, high mitotic index, can spread distantly (metastasis)
• Clonal proliferation or expansion


  As a result of a mutation, a cell acquires characteristics that allow it to have selective advantage over its neighbors
• Transformation of normal cells


  Decreased need for growth factors to multiply, lack contact inhibition, anchorage independence, immortality- Telomerase lengthens telomeres
• Six hallmarks of cancer cells


  • Self-sufficiency in growth signals, insensitive to anti-growth signals, evade apoptosis signals, limitless proliferative ability, sustained angiogenesis, tissue invasion and metastasis
• Proto-oncogenes


  Normal genes that direct protein synthesis and cellular growth
• Oncogenes


  Mutated genes leading to uncontrolled cell growth
• Tumor-suppressor genes


  Encode proteins that in their normal state prevent proliferation, also referred to as anti-oncogenes
• Cell cycle checkpoints ensure that mitotic events occur in the correct sequence. Many cancers result from faulty checkpoints.
• Tumor markers


  • Substances produced by tumors, including hormones, enzymes, genes, antigens and antibodies
• Tumor markers


  • Alpha fetoprotein, Carcinoembryonic antigen (CEA), Prostate-specific antigen (PSA), Catacholamines, Urinary Bence Jones protein, Homovanillic acid
• Grading


  Histologic characterizations of tumor, degree of anaplasia (high or low-grade), greater anaplasia = greater malignant potential in general
• Grading of tumors


  • Grade 1: well differentiated with minimal deviation from tissue of origin
  • Grade 2: moderately well differentiated with evidence of structural changes from normal tissue of origin
  • Grade 3: poorly differentiated with extensive structural changes from tissue of origin
  • Grade 4: very anaplastic with no resemblance to tissue of origin
• Staging


  Describes the location and pattern of spread of a tumor, including tumor size, extent of local growth, lymph node and organ involvement, presence of distant metastases
• Clinical staging


  • Stage 0: cancer in situ
  • Stage I: localized tumor growth
  • Stage II: limited local spread
  • Stage III: extensive local and regional spread
  • Stage IV: metastasis
• The spleen also stores red blood cells and releases them into circulation when needed.
• The spleen filters blood to remove old or damaged red cells and platelets, as well as bacteria and other foreign substances.
• The spleen is the largest lymphoid organ, located on the left side of the abdomen.
• The spleen is involved in immune responses by producing antibodies against foreign substances and destroying old RBCs.
• The spleen filters the blood and removes damaged or abnormal cells, such as bacteria and viruses.
• The spleen plays a role in immune function by producing antibodies and white blood cells that fight infection.
• The spleen plays a role in removing pathogens from the bloodstream through phagocytosis.
• The spleen helps regulate fluid balance within the body by removing excess water and electrolytes from the bloodstream.
• The spleen plays a role in regulating the body's response to infection and inflammation.
• The spleen plays a role in immune function by producing antibodies and white blood cells that fight infection.
• The spleen helps regulate fluid balance between the intravascular compartment (blood) and extravascular compartment (tissues).
• The spleen produces white blood cells that fight infection and disease.
• The spleen produces hormones such as erythropoietin (EPO) which stimulates bone marrow to produce more red blood cells.
• The spleen produces hormones such as erythropoietin (EPO) which stimulates the production of red blood cells in response to low oxygen levels in the body.
• The spleen helps regulate the body's fluid balance by removing excess water from the bloodstream.
• The spleen helps regulate the number of circulating red blood cells (RBCs) through destruction of old or damaged ones.
• The spleen produces cytokines that stimulate B-cell production and activate T-cells.