Drug resistance in clinical practice: patterns of treatment failure in patients receiving systemic therapy for advanced breast cancer.
Strategies for overcoming the causes of drug resistance should take account of the patterns of treatment failure seen in clinical practice. We have analysed the patterns of disease progression in 267 patients with advanced breast cancer receiving systemic therapy. First disease progression on therapy most commonly occurred in tissues involved by tumour at the commencement of treatment. However in 40% of patients, first documentation of disease progression included a tissue not previously known to contain metastatic disease. In only 3% of patients was this new tissue the central nervous system. This pattern of disease progression was not influenced by treatment type (i.e. endocrine or cytotoxic), tumour response to treatment, oestrogen receptor status, prior adjuvant cytotoxic treatment, or disease free interval. These results question the wisdom of always ceasing existing therapy and substituting new treatment when progressive disease is first documented.
Harnett
P R
PR
Ludwig Institute for Cancer Research, University of Sydney, N.S.W., Australia.
Tattersall
M H
MH
Coates
A S
AS
van Couten
R
R
Forbes
J
J
D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology; D004351:Drug Resistance; D005260:Female; D006801:Humans; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local; D012189:Retrospective Studies
D000970:Antineoplastic Agents