Glutathione S-transferase Pi expression predicts response to adjuvant chemotherapy for stage C colon cancer: a matched historical control study.
BACKGROUND
This study examined the association between overall survival and Glutathione S-transferase Pi (GST Pi) expression and genetic polymorphism in stage C colon cancer patients after resection alone versus resection plus 5-fluourouracil-based adjuvant chemotherapy.


METHODS
Patients were drawn from a hospital registry of colorectal cancer resections. Those receiving chemotherapy after it was introduced in 1992 were compared with an age and sex matched control group from the preceding period. GST Pi expression was assessed by immunohistochemistry. Overall survival was analysed by the Kaplan-Meier method and Cox regression.


RESULTS
From an initial 104 patients treated with chemotherapy and 104 matched controls, 26 were excluded because of non-informative immunohistochemistry, leaving 95 in the treated group and 87 controls. Survival did not differ significantly among patients with low GST Pi who did or did not receive chemotherapy and those with high GST Pi who received chemotherapy (lowest pair-wise p = 0.11) whereas patients with high GST Pi who did not receive chemotherapy experienced markedly poorer survival than any of the other three groups (all pair-wise p <0.01). This result was unaffected by GST Pi genotype.


CONCLUSIONS
Stage C colon cancer patients with low GST Pi did not benefit from 5-fluourouracil-based adjuvant chemotherapy whereas those with high GST Pi did.
Cancer Pharmacology Unit, ANZAC Research Institute, Concord Hospital, The University of Sydney, Sydney, NSW 2139, Australia.
Lucy
L
Jankova
Graham
G
Robertson
Charles
C
Chan
King L
KL
Tan
Maija
M
Kohonen-Corish
Caroline L-S
CL
Fung
Candice
C
Clarke
Betty P C
BP
Lin
Mark
M
Molloy
Pierre H
PH
Chapuis
Les
L
Bokey
Owen F
OF
Dent
Stephen J
SJ
Clarke
D000368:Aged; D017024:Chemotherapy, Adjuvant; D003110:Colonic Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000401:mortality* / Q000473:pathology; D005260:Female; D015870:Gene Expression; D005838:Genotype; D051549:Glutathione S-Transferase pi / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D016896:Treatment Outcome
D051549:Glutathione S-Transferase pi