Glutathione S-transferase Pi expression predicts response to adjuvant chemotherapy for stage C colon cancer: a matched historical control study
1 Cancer Pharmacology Unit, ANZAC Research Institute, Concord Hospital, The University of Sydney, Sydney, NSW, 2139, Australia
2 Department of Anatomical Pathology, Concord Hospital and Discipline of Pathology, The University of Sydney, Sydney, NSW, 2139, Australia
3 Department of Anatomical Pathology, Concord Hospital, Sydney, NSW, 2139, Australia
4 Cancer Research Program, Garvan Institute of Medical Research and St Vincent’s Clinical School, University of New South Wales, Sydney, NSW, 2052, Australia
5 Australian Proteome Analysis Facility and Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW, 2109, Australia
6 Department of Colorectal Surgery, Concord Hospital and Discipline of Surgery, The University of Sydney, Sydney, NSW, 2139, Australia
7 Department of Medicine, Concord Hospital and Discipline of Medicine, The University of Sydney, Sydney, NSW, 2139, Australia
BMC Cancer 2012, 12:196 doi:10.1186/1471-2407-12-196Published: 28 May 2012
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.
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.
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.
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.