RT Book, Section
A1 Cole, Susan P.C.
A1 Tannock, Ian F.
A2 Tannock, Ian F.
A2 Hill, Richard P.
A2 Bristow, Robert G.
A2 Harrington, Lea
SR Print(0)
ID 1127473477
T1 Drug Resistance
T2 The Basic Science of Oncology, 5e
YR 2016
FD 2016
PB McGraw-Hill Education Medical
PP New York, NY
SN 9780071745208
LK hemonc.mhmedical.com/content.aspx?aid=1127473477
RD 2024/04/19
AB A  major  problem  with  systemic  treatment  of  cancers  is  the  presence  or  induction  of  drug  resistance  in  the  tumor  cells.  In  practice  many  types  of  cancer  that  occur  commonly  in  humans  (eg,  colon  cancer,  most  types  of  non–small  cell  lung  cancer,  pancreatic  cancer)  have  a  limited  response  to  treatment  with  current  anticancer  drugs.  Other  human  tumors  (eg,  breast  cancer,  ovarian  cancer,  or  small  cell  lung  cancer)  often  respond  to  initial  treatment,  but  acquired  resistance  to  further  therapy  usually  prevents  drug  treatment  from  being  curative.  Resistance  to  chemotherapy  may  have  multiple  causes,  and  the  most  widely  studied  of  these  are  genetically  determined  mechanisms  that  lead  to  resistance  of  the  individual  tumor  cells.  Sensitivity  to  drugs  may  differ  widely  among  cell  populations  from  tumors  and  normal  tissues  and  also  among  the  cells  of  a  single  tumor.  The  selection  or  induction  of  a  drug  resistant  subpopulation  in  human  tumors  is  a  major  factor  limiting  the  efficacy  of  clinical  chemotherapy.  Even  if  drug-resistant  cells  are  present  initially  only  at  low  frequency  (eg,  1  drug  resistant  cell  per  105  drug-sensitive  cells),  their  selective  advantage  during  drug  treatment  will  lead  to  their  rapid  emergence  as  the  dominant  cell  population,  giving  the  clinical  impression  of  "acquired  resistance."