RT Book, Section
A1 Panus, Peter C.
A1 Jobst, Erin E.
A1 Masters, Susan B.
A1 Katzung, Bertram
A1 Tinsley, Suzanne L.
A1 Trevor, Anthony J.
SR Print(0)
ID 6095262
T1 Chapter 31. Cancer Chemotherapy
T2 Pharmacology for the Physical Therapist
YR 2009
FD 2009
PB The McGraw-Hill Companies
PP New York, NY
SN 978-0-07-146043-9
LK accessphysiotherapy.mhmedical.com/content.aspx?aid=6095262
RD 2024/04/24
AB Cancer  is  a  disease  of  cells  characterized  by  a  shift  in  the  control  mechanisms  that  govern  cell  proliferation  and  differentiation.  Cells  that  have  undergone  neoplastic  transformation  often  express  normal  fetal  cell  surface  antigens  or  display  other  signs  of  apparent  immaturity.  Cancer  cells  may  also  exhibit  qualitative  or  quantitative  chromosomal  abnormalities,  including  translocations  and  amplified  gene  sequences.  Cancer  cells  proliferate  excessively  and  form  local  tumors  that  can  compress  or  invade  adjacent  normal  structures.  Within  local  tumors,  a  small  subpopulation  of  cells  can  be  described  as  tumor  stem  cells.  These  cells  retain  the  ability  to  undergo  repeated  cycles  of  proliferation  and  can  migrate  to  distant  sites  in  the  body  to  colonize  various  organs  in  the  process  called  metastasis.  Thus,  tumor  stem  cells  can  express  clonogenic  (colony-forming)  capabilities.  Chromosomal  abnormalities  in  tumor  stem  cells  reflect  their  genetic  instability,  which  leads  to  progressive  selection  of  subclones  that  can  survive  more  readily  in  the  host’s  multicellular  environment.  Abnormalities  in  various  metabolic  pathways  and  cellular  components  (e.g.,  expression  of  cell-surface  drug  transporters)  accompany  neoplastic  progression.  The  invasive  and  metastatic  processes,  as  well  as  metabolic  abnormalities  resulting  from  the  cancer,  cause  illness  and  eventual  death  unless  the  neoplasm  can  be  eradicated  with  treatment.