11: Oncology Flashcards
Which cancer is improved by surgical debulking?
Ovarian cancer
[Ovarian cancer is one of the few tumors for which surgical debulking improves chemotherapy (not seen in other tumors).]
What does suspicious lymphadenopathy at the following locations indicate?
- Supraclavicular nodes
- Axillary nodes
- Periumbilical nodes
- Supraclavicular nodes: Neck, breast, lung, stomach (Virchow’s node), or pancreas cancer
- Axillary nodes: Lymphoma (#1), breast cancer, ;or melanoma
- Periumbilical nodes: Pancreatic cancer (Sister Mary Joseph’s node)
What do elevations in the following tumor markers suggest?
- PSA
- NSE
- BRCA I & II
- Chromogranin A
- Ret oncogene
- PSA: Prostate cancer
- NSE: Small cell lung cancer, neuroblastoma
- BRCA I & II: Breast cancer
- Chromogranin A: Carcinoid tumor
- Ret oncogene: Thyroid medullary cancer
[PSA is thought to be the tumor marker with the highest sensitivity although specificity is low.]
Which chromosome are the following tumor suppressor genes located on and what process are they involved in?
- DCC
- bcl
- BRCA
- DCC: Chromosome 18, involved in cell adhesion
- bcl: Chromosome 18 (often gets translocated) Involved in apoptosis
- BRCA: BRCA-1 is on chromosome 17, BRCA-2 is on chromosome 13, Involved in DNA repair
Which two tumors are particularly susceptible to XRT and which two tumors are not?
- Susceptible: Seminomas, lymphomas
- Resistant: Epithelial tumors, sarcomas
[Large tumors are less responsive to XRT due to lack of oxygen in the tumor.]
What is the clinical question that one is attempting to answer in each of the following phases of clinical trials?
- Phase I
- Phase II
- Phase III
- Phase IV
- Phase I: Is it safe and at what dose?
- Phase II: Is it effective?
- Phase III: Is it better than existing therapy?
- Phase IV: Implementation and marketing
What do elevations in the following tumor markers suggest?
- CEA
- AFP
- CA 19-9
- CA 125
- Beta-HCG
- CEA: Colon cancer
- AFP: Liver cancer
- CA 19-9: Pancreatic cancer
- CA 125: Ovarian cancer
- Beta-HCG: Testicular cancer, choriocarcinoma
What is defective with a mutation in the following proto-oncogenes?
- ras
- src
- sis
- erb B
- myc
- ras: G-protein defect
- src: Tyrosine kinase defect
- sis: Platelet-derived growth factor receptor defect
- erb B: Epidermal growth factor receptor defect
- myc: Transcription factor (mutation leads to constitutive expression)
What is the mechanism of action of the below chemotherapy agents?
- Methotrexate
- 5-Fluorouracil (5-FU)
- Doxorubicin
- Etoposide
- Methotrexate: Inhibits dihydrofolate reductase (DHFR) which inhibits purine and DNA synthesis
- 5-Fluorouracil (5-FU): Inhibits thymidylate synthestase which inhibits purine and DNA synthesis
- Doxorubicin: DNA intercalator that inhibits the progression of topoisomerase II once it has broken the DNA chain for replication, preventing the DNA double helix from being resealed and therby stopping replication
- Etoposide: Inhibits topoisomerase by forming a ternary complex with DNA and topoisomerase II, preventing re-ligation of DNA strands and causing DNA strands to break
Which chromosome are the following tumor suppressor genes located on and what process are they involved in?
- Retinoblastoma
- p53
- APC
- Retinoblastoma: Chromosome 13, involved in cell cycle regulation
- p53: Chromosome 17, normal gene induces cell cycle arrest and apoptosis (abnormal gene allows unrestrained cell growth)
- APC: Chromosome 5, involved with cell cycle regulation and movement
What is the mechanism of action of the below chemotherapy agents?
- Taxol
- Vincristine and Vinblastine
- Cisplatin and Carboplatin
- Cyclophosphamide
- Taxol: Promotes microtubule formation and stabilization that cannot be broken down, causing cells to rupture
- Vincristine and Vinblastine: Microtubule inhibitors that bind tubulin and stop the cell from separating its chromosomes during metaphase, causing the cell to undergo apoptosis
- Cisplatin and Carboplatin: Platinum alkylating agents that crosslink DNA, inhibiting DNA repair and/or synthesis
- Cyclophosphamide: Acrolein is the active metabolite. It is an alkylating agent that transfers alkyl groups, forming irreversible covalent bonds to DNA and inducing apoptosis
Mutations in which 4 genes can lead to colon cancer?
- APC (cell cycle regulation and movement)
- p53 (Cell cycle regulation)
- DCC (Cell adhesion)
- K-ras: (G protein signal transduction)
[APC is thought to be the initial step in the evolution of colorectal cancer. Colon cancer usually doesnt go to the bone.]
Which solid tumors are curable with chemotherapy alone?
Hodgkin’s and non-Hodgkin’s lymphoma
What does a PET-scan detect on a chemical level?
Fluorodeoxyglucose molecules
[Used to detect metastasis.]
What can be administered for neutrophil recovery after chemotherapy?
Granulocyte colony-stimulating factor (GCSF)
[Pharmaceutical analogs of naturally occuring GCSF are called filgrastim and lenograstim. GCSF is a glycoprotein that stimulates the bone marrow to produce granulocytes and stem cells and release them into the bloodstream. GCSF can cause Sweet’s syndrome (acute febrile neutropenic dermatitis).]
