Tumor Immunology PDF

11 TUMOR IMMUNOLOGY Tumor Immunology The study of the relationship between the immune system and cancer cells. Hanhan and Weinberg defined a cancerous cells as one that exhibits: Sustained signaling of proliferation Resistance to cell death Ability to induce angiogenesis Immortality in term...

11 TUMOR IMMUNOLOGY Tumor Immunology The study of the relationship between the immune system and cancer cells. Hanhan and Weinberg defined a cancerous cells as one that exhibits: Sustained signaling of proliferation Resistance to cell death Ability to induce angiogenesis Immortality in terms of division Invasion and metastasis Ability to avoid suppressors of cell growth Reprogramming of energy metabolism to support malignant cells Ability to evade destruction by immune system Genomic instability and mutations Inflammatory responses that promote tumor growth  TUMOR ANTIGENS The concept of tumor immunology is based on the premise that tumors possess antigens that are recognized as foreign by the immune system. Antigen unique to the tumor of an individual TUMOR-SPECIFIC patient or shared by a ANTIGENS (TSAS) limited number of patients with the same type of tumor. Expressed in BOTH normal TUMOR-ASSOCIATED cells and tumors cells. ANTIGENS (TAAS) Tumor cells abnormally express these antigens. TUMOR MARKERS Biological substances that are found in increased amounts in the blood, body fluids, or tissues of patient with a specific type of cancer. An ideal tumor marker should have characteristics. A marker should: a. Be produced by the tumor itself or by the patient's body in response to the tumor. b. Be secreted into biological fluid, where it can be inexpensively and easily quantified. c. Have a circulating half-life long enough to permit its concentration to rise with increasing tumor load. d. Increase to clinically significant levels above the reference level while the disease is still treatable. e. Have a high sensitivity. Easily detectable. f. Should be absent in all individuals without the malignant disease. Clinical use of tumor markers: Screening Diagnosis Prognosis Monitoring response to treatment  ALPHA-FETOPROTEIN (AFP) Nonseminomatous testicular germ cell Liver B2-microglobulin B-lymphocyte malignancies Calcitonin and CaLCIUM Familial medullary thyroid carcinoma  CD markers WBC CARCINOEMBRYONIC ANTIGEN (CEA) Colorectal Breast Lung CA 125 Ovarian adenocarcinoma  CA 15-3 Breast Pancreatic Lung Colorectal Ovarian Liver CA 19-9 Pancreatic ER/PR Breast adenocarcinoma  hCG Nonseminomatous testicular germ cell Trophoblastic (hydatiform mole, choriocarcinoma) HER2 (neu) or neu Breast (check for response to trastuzumab therapy) Monoclonal free Ig light chains Plasma cell B lymphocyte  Monoclonal Igs Plasma cell B lymphocyte PSA Prostate PTH and Ca2+ Parathyroid carcinoma Thyroglobulin Thyroid hUMAN CHORIONIC GONADOTROPIN (hcg) "Pregnancy hormone" Synthesized by trophoblasts Compose of two subunits: Shared with luteinizing hormone, (LH), a-hCG follicle-stimulating hormone (FSH), and thyroid stimulating hormone (TSH). b-hCG Unique to hCG Thyroglobulin Large glycoprotein produced by the thyroid gland. It serves as a precursor for thyroid hormones, thyroxine (T4) and triiodothyronine (T3) Both normal thyroid tissue and thyroid cancer cells produce thyroglobulin. Reflects thyroid mass, injury, and TSH levels.