COX-2 verexpression in pretreatment biopsies predicts response of rectal cancers to neoadjuvant radiochemotherapy
- Departments of Surgery and Histopathology, and Academic Unit of Clinical and Molecular Oncology, St. James's Hospital, Dublin (Ireland)
- Department of Histopathology, Beaumont Hospital and Royal College of Surgeons in Ireland, Dublin (Ireland)
- Department of Histopathology, Adelaide and Meath Hospital, Tallaght, Dublin (Ireland)
- Departments of Surgery and Histopathology, Academic Unit of Clinical and Molecular Oncology, St. James's Hospital, Dublin (Ireland)
Purpose: To determine the utility of COX-2 expression as a response predictor for patients with rectal cancer who are undergoing neoadjuvant radiochemotherapy (RCT). Methods and Materials: Pretreatment biopsies (PTB) from 49 patients who underwent RCT were included. COX-2 and proliferation in PTB were assessed by immunohistochemistry (IHC) and apoptosis was detected by TUNEL stain. Response to treatment was assessed by a 5-point tumor-regression grade (TRG) based on the ratio of residual tumor to fibrosis. Results: Good response (TRG 1 + 2), moderate response (TRG 3), and poor response (TRG 4 + 5) were seen in 21 patients (42%), 11 patients (22%), and 17 patients (34%), respectively. Patients with COX-2 overexpression in PTB were more likely to demonstrate moderate or poor response (TRG 3 + 4) to treatment than were those with normal COX-2 expression (p = 0.026, chi-square test). Similarly, poor response was more likely if patients had low levels of spontaneous apoptosis in PTBs (p = 0.0007, chi-square test). Conclusions: COX-2 overexpression and reduced apoptosis in PTB can predict poor response of rectal cancer to RCT. As COX-2 inhibitors are commercially available, their administration to patients who overexpress COX-2 warrants assessment in clinical trials in an attempt to increase overall response rates.
- OSTI ID:
- 20793306
- Journal Information:
- International Journal of Radiation Oncology, Biology and Physics, Vol. 64, Issue 2; Other Information: DOI: 10.1016/j.ijrobp.2005.07.961; PII: S0360-3016(05)02210-8; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0360-3016
- Country of Publication:
- United States
- Language:
- English
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