4. Uncontrolled growth and cell
proliferation results in mass (tumor)
•That invades neighboring tissues and may
metastasize to more distant sites.
•Some cancers, do not form tumors (Blood, Skin
etc.)
•Its most common and severe problems of clinical
medicine.

22. p53
• Encodes a phosphoprotein with 53,000 MW.
• It blocks the cells that have damaged DNA by triggering the
blocking of cell division until the damage is repaired.
• If the DNA damage is severe, it directs the cell to commit
suicide by triggering apoptosis.
• Most tumours absence of p53, others show mutant non-
functional p53.
• Suppress transformation ability of oncogenic viruses and also
activates the expression of genes that suppress cell
proliferation.

28. Common Tumor Markers
Name Increased in
Alpha Fetoprotein Hepatoma, Germ cell Tumours
Carcinoembryonic antigen Colorectal, Gastro and Lung Cancer
Beta HCG Choriocarcinoma
Prostate Specific Antigen Prostate cancer
Calcitnin Medullary carcinoma of Thyroid
CA -125 Ovarian cancer
Alkaline phosphatase Bone secondaries
Neuronal specific enolase Nervous system cancer
Bence Jones Protein Lymphatic Cancer

33. Anticancer Drugs
Surgery and radiotherapy – most
effective to reduce the initial tumour load.
Chemotherapy - cytotoxic drugs reduces
doubling time of cancer cells

34. Common anticancer drugs
Name Type Mode of action
Methotrexate Folic acid
analogue
Competitive inhibitor of
dihydrofolate reductase.
THFA-nucleotide synthesis
6-Mercapto
purine
Purine
analogue
Inhibits the conversion of
IMP to AMP
5-fluoro uracil Pyrimidine
analogue
Inhibits thymidylate synthase
Cyclo-
phosphamide
Alkylating
agent
Cross linking of bases of DNA;
inhibition of strand separation