A prospective phase I–II trial of the cyclooxygenase-2 inhibitor celecoxib in patients with carcinoma of the cervix with biomarker assessment of the tumor microenvironment

Purpose: To evaluate the toxicity and effectiveness of celecoxib in combination with definitive chemoradiotherapy (CRT) in women with locally advanced cervical cancer. Methods and Materials: Thirty-one patients were accrued to a phase I–II trial of celecoxib 400 mg by mouth twice per day for 2 weeks before and during CRT. Tumor oxygenation (HP 5 ) and interstitial fluid pressure (IFP) were measured before and 2 weeks after celecoxib administration alone. The median follow-up time was 2.7 years (range, 1.1–4.4 years). Results: The most common acute G3/4 toxicities were hematologic (4/31, 12.9%) and gastrointestinal (5/31, 16.1%) largely attributed to chemotherapy. Late G3/4 toxicity was seen in 4 of 31 patients (13.7% actuarial risk at 2 yr), including fistulas in 3 patients (9.7%). Within the first year of follow-up, 25 of 31 patients (81%) achieved complete response (CR), of whom 20 remained in CR at last follow-up. After 2 weeks of celecoxib administration before CRT, the median IFP decreased slightly (median absolute, –4.6 mm Hg; p = 0.09; relative, –21%; p = 0.07), whereas HP 5 did not change significantly (absolute increase, 3.6%; p = 0.51; median relative increase, 11%; p = 0.27). No significant associations were seen between changes in HP 5 or IFP and response to treatment ( p = 0.2, relative HP 5 change and p = 0.14, relative IFP change). Conclusions: Celecoxib in combination with definitive CRT is associated with acceptable acute toxicity, but higher than expected late complications. Celecoxib is associated with a modest reduction in the angiogenic biomarker IFP, but this does not correspond with tumor response.