Intro to Oncology Flashcards
What is initiation in carcinogenesis?
Exposure of normal cells to carcinogenic substances
What is promotion in carcinogenesis?
Carcinogens or other factors create an environment that favors growth of mutated cells over normal cells
What is conversion or transformation of carcinogenesis?
Cell becomes cancerous
Could be years before diagnosis occurs
What is progression of carcinogenesis?
Tumor invasion into local and distal sites (metastasis)
Which process in carcinogenesis is reversible?
Promotion
What are RFs for carcinogenesis?
Chemical Physical agents Biologic Age/gender Diet Chronic irritation FH
What are chemical RFs for carcinogenesis?
Aniline dye exposure (bladder cancer)
Benzene (leukemia)
Smoking
Drugs/hormones (BC, Hydroxyurea, GLP-1 agonists, AZA)
What are the physical agents RFs for carcinogenesis?
Radiation (free radicals)
UV (free radicals)
How is chronic irritation a RF for carcinogenesis?
Persistent cell damage and repair
What are the two major classes of genes in cancer?
Oncogenes
Proto-oncogenes
What are oncogenes?
Develop from normal genes called proto-oncogenes
What are proto-oncogenes?
Present in all cells to regulate cell cycle and function
How do proto-oncogenes become oncogenes?
Alterations lead to oncogenes by point mutations, chromosomal rearrangements, or gene amplification
What are some examples of oncogenes?
ALK EGFR HER2 KRAS/NRAS RET BCR-ABL BCL-2
What function is the oncogene ALK?
Kinase
What are the cancers associated with ALK?
Lung
Lymphoma
Ovarian
What function is the oncogene EGFR?
Growth factor receptor
What cancers are associated with EGFR?
Breast
Head/neck
Colon
What function is the oncogene HER2?
Growth factor receptor
What cancers are associated with HER2?
Breast
Ovarian
Bladder
Prostate
What is the function of the oncogene KRAS/NRAS?
Cytoplasmic protein in signaling pathway
What cancers are associated with KRAS/NRAS?
Colon
Lung
Acute leukemia
What is the function of the oncogene RET?
Growth factor receptor
What cancers are associated with RET?
Thyroid
Lung
What is the function of the oncogene BCR-ABL?
Cytoplasmic kinase
What cancers are associated with BCR-ABL?
Chronic myeloid leukemia
What is the function of BCL-2?
Blocks apoptosis
What cancers are associated with BCL-2?
Indolent B-cell lymphoma
How are tumor suppressor genes involved in cancer?
Regulate and inhibit inappropriate cell growth and cell proliferation
What does mutation or loss of the gene lead to?
Uncontrolled, unregulated, unchecked, and unimpeded cell growth
What are DNA repair genes classified as?
Tumor suppressor genes
Which tumor suppressor gene is thought to be mutated in 1/2 of all cancers?
p53
What are some Tumor suppressor genes?
p53 BCRA1 BCRA2 APC RB1
What is the function of p53?
Halts cell division
Induces apoptosis
What is the function of BRCA1 and BRCA2?
DNA repair
What cancers are associated with BRCA1 and BRCA2?
Breast
Ovarian
What is the function of APC?
Cytoplasmic signaling step