COX-2 Inhibition With Celecoxib Does Not Improve Breast Cancer Outcomes

The following article features coverage from the San Antonio Breast Cancer Symposium (SABCS) 2017 meeting. Click here to read more of Cancer Therapy Advisor‘s conference coverage.

COX-2 inhibition with celecoxib does not prolong disease free survival (DFS) or overall survival (OS) among patients who undergo complete resection of primary breast cancer, with or without adjuvant or neoadjuvant chemotherapy and/or radiotherapy, according to findings presented at the 2017 San Antonio Breast Cancer Symposium.¹

“Translational research is in progress to see if a celecoxib signature predictive of benefit can be identified,” said lead study author R. Charles Coombes, MD, PhD, of Imperial College London in England.

Elevated COX2 levels are associated with breast cancer progression. COX2 is transcriptionally regulated and enhances the aromatase pathway, especially in estrogen receptor–positive tumors, Dr Coombes noted. Preclinical research involving lab animal models of breast cancer suggested that COX-2 inhibition attenuates the development of metastatic disease.

Between 2007 and 2012, 2639 patients with completely resected breast cancer and prior local and systematic adjuvant treatment were randomly assigned (2:1) to receive celecoxib (1763 patients; 400 mg once daily) or placebo (876 patients; once daily) for 2 years. Patients with HER2-positive or T1 node-negative (T1N0) grade 1 disease were excluded from the trial.

DFS at 2 years did not differ between the study groups (hazard ratio, 0.99; P = .91) and this finding was not affected by estrogen receptor status in subgroup analyses. Overall survival was also similar between the study groups (hazard ratio, 0.98; P = .90).

There were no cardiovascular events in the study. The only adverse event attributable to celecoxib was shortness of breath. Twenty percent of celecoxib group patients and 19% of placebo group patients discontinued trial participation “for a variety of reasons,” Dr Coombes noted.

Read more of Cancer Therapy Advisor‘s coverage of the San Antonio Breast Cancer Symposium (SABCS) 2017 meeting by visiting the conference page.

Reference

1. Coombes RC, Tovey H, Kilburn L, et al. A phase III multicentre double blind randomised trial of celecoxib versus placebo in primary breast cancer patients (REACT – Randomised EuropeAn celecoxib trial). Oral presentation at: 2017 San Antonio Breast Cancer Symposium; December 5-9, 2017; San Antonio, TX.