The effect of the selective cyclooxygenase-2 inhibitor rofecoxib on human colorectal cancer liver metastases.
OBJECTIVE
Cyclooxygenase-2 (COX-2) is a potential target for chemotherapy of colorectal cancer (CRC). We tested the antineoplastic activity of the selective COX-2 inhibitor rofecoxib on human CRC liver metastases by measuring surrogate markers of tumor growth and angiogenesis in a randomized, double-blind, placebo-controlled trial.


METHODS
Patients undergoing liver resection surgery for metastatic disease were randomized to receive rofecoxib 25 mg daily or placebo before surgery (duration, >14 days). The apoptosis index (AI; neocytokeratin 18), proliferation index (PI; Ki-67), and microvessel density (MVD; CD31) were measured in metastases by immunohistochemistry. The effect of rofecoxib on COX-2-positive HCA-7 human CRC cell PGE(2) synthesis, proliferation, and apoptosis in vitro was also investigated.


RESULTS
Patients who received rofecoxib (n = 23) and placebo (n = 21) were well matched regarding clinical and metastasis characteristics. The mean (range) duration of rofecoxib therapy was 26 (14-46) days. Rofecoxib-treated metastases had a 29% decrease in MVD (mean, 25.1 [SEM, 2.7] per hpf) compared with placebo-treated tissue (32.5 [SEM, 4.5] per hpf; P = 0.15). There was little difference in AI (rofecoxib mean, 2.03% [SEM, 0.43%] vs. placebo 1.39% [SEM, 0.39%]) or PI (rofecoxib 54.7% [SEM, 5.1%] vs. placebo 52.6% [SEM, 5.6%]). Rofecoxib-induced growth arrest and apoptosis of HCA-7 cells occurred only at concentrations (>10 micromol/L), which were significantly higher than the IC(50) for COX-2 inhibition.


CONCLUSIONS
Rofecoxib may negatively regulate angiogenesis in human CRC liver metastases. The absence of a significant, direct effect of rofecoxib on epithelial cells in liver metastases in vivo mirrors the lack of activity on human CRC cells at pharmacologically relevant concentrations in vitro.
Fenwick
Stephen W
SW
Molecular Medicine Unit, University of Leeds, Leeds, United Kingdom.
Toogood
Giles J
GJ
Lodge
J Peter A
JP
Hull
Mark A
MA
D000368:Aged; D017209:Apoptosis / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D015179:Colorectal Neoplasms / Q000098:blood supply / Q000188:drug therapy*; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000627:therapeutic use*; D015232:Dinoprostone / Q000096:biosynthesis; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000037:antagonists & inhibitors*; D007783:Lactones / Q000627:therapeutic use*; D008113:Liver Neoplasms / Q000098:blood supply / Q000556:secondary*; D008297:Male; D008565:Membrane Proteins; D008875:Middle Aged; D011451:Prostaglandin-Endoperoxide Synthases; D013450:Sulfones
D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D007527:Isoenzymes; D007783:Lactones; D008565:Membrane Proteins; D013450:Sulfones; C116926:rofecoxib; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D015232:Dinoprostone