Chemotherapy induces the expression of cyclooxygenase-2 in non-small cell lung cancer

Purpose: To determine the effect of taxane-based chemotherapy on intratumoral levels of cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2) in patients with non-small cell lung cancer (NSCLC). Experimental Design: Lung specimens obtained at the time of surgery were used to measure levels of COX-2 and PGE₂ in tumors and adjacent nontumorous tissues in three subsets of NSCLC patients who underwent: (A) surgical resection only (n = 16); (B) surgical resection after preoperative taxane-based chemotherapy (n = 13); or (C) surgical resection after preoperative chemotherapy coadministered with the selective COX-2 inhibitor, celecoxib 400 mg bid (n = 17). Results: Levels of intratumoral PGE₂ were nearly 3-fold higher among patients who received preoperative chemotherapy compared with those treated by surgery alone (P < 0.001). This difference was abrogated by the addition of celecoxib to preoperative chemotherapy (P < 0.001). Amounts of intratumoral COX-2 were ∼ 3-fold higher in groups of patients who received preoperative chemotherapy with celecoxib (P < 0.0001) or without celecoxib (P < 0.001), compared with the group who underwent surgical resection only. Importantly, statistically significant positive correlations between COX-2 and PGE₂ were observed in the surgery only (r = 0.502, P = 0.047) and preoperative chemotherapy groups (=0.740, P = 0.004); this correlation was abrogated when celecoxib was given with chemotherapy (r = 0.005, P = 0.98). Conclusions: Treatment with chemotherapy led to increased amounts of COX-2 and PGE ₂ in NSCLC. Cotreatment with celecoxib abrogated the increase in levels of PGE₂ but not COX-2 induced by chemotherapy. Importantly, these results clearly show that levels of a pharmacologic target (i.e., COX-2) can be affected by both the intrinsic molecular properties of a tumor and therapy.