Tumor Immunology

Question 1

tumors that have severe ____ have a better prognosis than those that do not

Answer 1

tumors that have severe lympho-reticular filtration have a better prognosis than those that do not

Question 2

describe the 2 types of tumor antigens

Answer 2

• tumor associated antigens (TAA)
  
  • are more common and found on tumor cells and on normal cells during fetal life (oncofetal antigens) and after birth in selected organs at low concentration
• tumor specific antigens (TSTA)
  
  • present only on tumor cells (usually viral induced) but not normal cells

Question 3

describe the role of AFP and tumors

Answer 3

• the normal range of AFP concentrations in humans is 0-20 ng/ml
  
  • this level rises considerable in patients with hepatomas and non-seminal testicular carcinomas
• a 5-fold or higher rise in this protein is used for monitoring hepatomas and testicular cancers
• AFP level may also be raised in some non-malignants conditions such as:
  
  • cirrhosis
  • hepatitis
  • other forms of liver damage

Question 4

describe the role of carinoembryonic antigen (CEA) and tumors

Answer 4

• CEA levels in normal people range up to 2.5 ng/ml
• they increase significantly in certain malignancies, particularly colorectal cancers
• they may also rise in some non-malignant conditions:
  
  • chronic cirrhosis
  • pulmonary emphysema
  • heavy smoking
• levels that are 4-5 times normal have been used to predict recurrence of colorectal tumors

Question 5

name viruses that are involved in human malignancies

Answer 5

• HTLV-1 = leukemia
• hepatitis-B virus = hepatic carcinoma
• papilloma virus = cervical cancer

Question 6

name the major human oncogenic viruses

Answer 6

• DNA viruses
  
  • small DNA tumor viruses
    
    • HPV
    • SV40
    • adenovirus
  • herpesviruses (large)
    
    • EBV
    • Kaposi’s sarcoma herpesvirus (KSHV)
• RNA viruses
  
  • human T-cell leukemia virus 1 (HTLV1)
  • hepatitis virus C