Oncology
- G1: most variable period of cell cycle. Growth factors act here
- Radiation therapy: M phase most sensitive; most effective with high O2
levels; higher engery = less skin damage; path: obliterative endarteritis;
decrease healing due to impaired fibroblasts
- Extremity Sarcoma biopsy:
excisional
if <4cm, otherwise longitudinal incision,
incisional
biopsy (less lymphatic disruption, easier to excise scar if biopsy +).
Post-op RT if high grade sarcoma, close margins, or tumor >5cm
- Li Fraumeni syndrome: p53 mutation. Sarcomas, breast CA, brain tumor,
leukemia
- Sarcomas generally spread hematogenously, not to lymphatics.
Staging based on grade, not size/nodes
- Colon CA associated with loss of APC gene, p53, DCC (deleted in colon
cancer), k-ras activation
- Breast CA associated with p53, bcl-2, cmyc, cmyb, her 2 neu
- C-myc associated with small cell lung CA, neuroblastoma, Burkitt's
lymphoma
- Bcl-2 gene regulates Apoptosis; p53 and c-myc also associated with
apoptosis
- Sis oncogene is homologous to PDGF
- Erb B codes for epidermal growth factor receptor. Associated with
decreased survival in breast CA
- K ras proto oncogene encodes for GTP protein; 90% of pancreatic CA, 50% of
colon CA, also in lung CA
- Ret proto-oncogene diagnostic for Medullary Thyroid Cancer. Patient with
family history of MEN who has Ret proto-oncogene should have total
thyroidectomy
- Tamoxifen (binds Estrogen Receptor) shown to decrease Breast CA in high
risk; risk DVT, endometrial CA
- Bleomycin and Busulfan both have pulmonary fibrosis as
complications
- Vincristine, cisplastin both cause neurotoxicity
- Levamisole mechanism: immunostimulant; is an antihelminthic agent
Return to Absite Review