Rofecoxib and cardiovascular adverse events in adjuvant treatment of colorectal cancer.

BACKGROUND: Selective cyclooxygenase inhibitors may retard the progression of cancer, but they have enhanced thrombotic potential. We report on cardiovascular adverse events in patients receiving rofecoxib to reduce rates of recurrence of colorectal cancer. METHODS: All serious adverse events that were cardiovascular thrombotic events were reviewed in 2434 patients with stage II or III colorectal cancer participating in a randomized, placebo-controlled trial of rofecoxib, 25 mg daily, started after potentially curative tumor resection and chemotherapy or radiotherapy as indicated. The trial was terminated prematurely owing to worldwide withdrawal of rofecoxib. To examine possible persistent risks, we examined cardiovascular thrombotic events reported up to 24 months after the trial was closed. RESULTS: The median duration of active treatment was 7.4 months. The 1167 patients receiving rofecoxib and the 1160 patients receiving placebo were well matched, with a median follow-up period of 33.0 months (interquartile range, 27.6 to 40.1) and 33.4 months (27.7 to 40.4), respectively. Of the 23 confirmed cardiovascular thrombotic events, 16 occurred in the rofecoxib group during or within 14 days after the treatment period, with an estimated relative risk of 2.66 (from the Cox proportional-hazards model; 95% confidence interval [CI], 1.03 to 6.86; P=0.04). Analysis of the Antiplatelet Trialists' Collaboration end point (the combined incidence of death from cardiovascular, hemorrhagic, and unknown causes; of nonfatal myocardial infarction; and of nonfatal ischemic and hemorrhagic stroke) gave an unadjusted relative risk of 1.60 (95% CI, 0.57 to 4.51; P=0.37). Fourteen more cardiovascular thrombotic events, six in the rofecoxib group, were reported within the 2 years after trial closure, with an overall unadjusted relative risk of 1.50 (95% CI, 0.76 to 2.94; P=0.24). Four patients in the rofecoxib group and two in the placebo group died from thrombotic causes during or within 14 days after the treatment period, and during the follow-up period, one patient in the rofecoxib group and five patients in the placebo group died from cardiovascular causes. CONCLUSIONS: Rofecoxib therapy was associated with an increased frequency of adverse cardiovascular events among patients with a median study treatment of 7.4 months' duration. (Current Controlled Trials number, ISRCTN98278138 [controlled-trials.com].).

Sudden death in patients receiving drugs tending to prolong the QT interval.

AIMS: To examine risks of sudden death in the community associated with drugs grouped by their risk of causing torsades de pointes (TdP) and to explore the risks for individual drugs. METHODS: Case-control study comparing prior drug intakes and morbidities, using the Arizona classification of drugs causing TdP. Participants included 1010 patients dying suddenly where post-mortem examination did not identify a clear cause of death, and 3030 matched living controls from primary care. RESULTS: Noncardiac drug risk was posed by antipsychotics and antidepressants. Significantly raised odds ratios (ORs) were found for takers of typical and atypical antipsychotics, ORs [95% confidence interval] 3.94 (2.05, 7.55) and 4.36 (2.54, 7.51), and of selective serotonin reuptake inhibitors [SSRIs] rather than tricyclic antidepressants, ORs 2.21 (1.61, 3.05) and 1.44 (0.96, 2.13). No significant risk was associated with other, noncardiac or psychiatric drugs, OR 1.09 (0.85, 1.41). Arizona classified drugs considered to raise risk of TdP were associated with raised risk of sudden death, as were those only weakly associated with TdP and not considered to pose a risk in normal use, ORs 2.08 (1.45, 3.00) and 1.74 (1.33, 2.28), respectively. CONCLUSIONS: Atypical and typical antipsychotic drug use were both strongly associated with raised risks, as were SSRIs. Tricyclic antidepressants were not associated with raised risks. The Arizona classification of risk of TdP was a poor predictor of likelihood of noncardiac drug-associated sudden death.

Protein kinase C delta is not activated by caspase-3 and its inhibition is sufficient to induce apoptosis in the colon cancer line, COLO 205.

Activation of protein kinase C delta (PKCdelta) is believed to be pro-apoptotic. PKCdelta is reported to be reduced in colon cancers. Using a colon cancer cell line, COLO 205, we have examined the roles of PKCdelta in apoptosis and of caspase-3 in the activation and inhibition of PKCdelta. PKCdelta activation with bistratene A and its inhibition with rottlerin induced apoptosis. Effects of PKC activators and inhibitors were additive, suggesting that PKCdelta down-regulation was responsible for the effects on apoptosis. Different apoptotic pathways induced PKCdelta cleavage, but the fragment produced was inactive in kinase assays. Caspase-3 inhibition did not block DNA fragmentation or PKCdelta proteolysis despite blocking intracellular caspase-3 activity. Calpain inhibition with calpeptin did not prevent TPA-induced PKCdelta cleavage. We conclude that in colonocytes, inhibition of PKCdelta is sufficient to lead to caspase-3-independent apoptosis. Caspase-3 does not cleave PKCdelta to an active form, nor does caspase-3 inhibition block apoptosis.

Targets of 17beta-oestradiol-induced apoptosis in colon cancer cells: a mechanism for the protective effects of hormone replacement therapy?

Epidemiological studies show a strong link between postmenopausal hormone replacement therapy and decreased incidence of colorectal cancer. The colon cancer cell line, COLO 205, develops sensitivity to 17beta-oestradiol (E(2)) in apoptosis assays with increasing passage number (>40), and we hypothesised that genes selectively regulated in multiply passaged cells were likely to be important in E(2)-related apoptosis. Gene array analysis was used to compare the patterns of genes up- or down-regulated in E(2)-sensitive and -insensitive cells. For some genes, changes in mRNA expression were confirmed by protein expression analyses. Changes found in response to E(2) in multiply passaged cells, but not minimally passaged cells, included induction of growth arrest and DNA damage-inducible protein 153 (GADD153), and repression of Kirsten-Ras 2B (K-Ras-2B), metastasis inhibition factor NM23 and vascular endothelial growth factor. A second group of genes was regulated with E(2) exposure in both cell types, and is unlikely to be critically involved in E(2)-associated apoptosis. These included up-regulation of butyrate response factor 1 (BRF1) and down-regulation of c-jun and the breast cancer associated ring domain gene known as BARD1. By comparing control arrays from the two cell populations, cAMP-response element-binding protein (CBP), which is associated with steroid receptor-dependent target gene transcription and the oncoprotein, tyrosine kinase-T3 (TRK-T3), were up-regulated whereas retinoic acid receptor alpha (RARalpha) was down-regulated in multiply passaged cells. This study provides evidence for selective regulation of genes in colon cancer cells by E(2), indicates which of those regulated are likely to be involved in induced apoptosis, and suggests genes likely to be responsible for facilitation.

NSAIDs and gastrointestinal cancer prevention.

Numerous studies report the relationship between aspirin and other nonsteroidal anti-inflammatories (NSAIDs) and cancer incidence, in particular for colorectal cancer. This paper systematically reviews the evidence of the effect of aspirin and other NSAIDs on the primary prevention of colorectal and other gastrointestinal cancers in the general population. In 25 investigations of NSAIDs and colorectal cancer, 23 observational studies reported a relative risk reduction but estimates vary widely. Cohort studies generally indicate lesser reductions than case-control studies suggesting possible biases in the latter. Clear evidence of a dose relationship generally appears lacking but data do not indicate useful effects of aspirin in cardioprophylactic doses. Differences have otherwise not been detected between aspirin and other NSAIDs, nor between non-aspirin NSAIDs. There is some evidence that the risk of colorectal cancer reduces with increased duration of NSAID use. The lower incidence of oesophageal and gastric cancers results in smaller numbers of cases in the studies reporting these cancers, particularly in the cohort studies. The trend is for a risk reduction for oesophageal and gastric cancers in people taking NSAIDs, which is more likely to be statistically significant in the case-control studies. A very small number of observational studies have reported the relationship between NSAIDs and the incidence of pancreatic, gallbladder and liver cancers. These show no consistent relationship. In view of the inadequate information about optimal dose and duration of NSAIDs for colorectal cancer reduction, and the adverse effects of NSAIDs, we are not yet in a position to recommend NSAIDs for the primary prevention of colorectal cancer in the general population.

Adverse effects of conventional non-steroidal anti-inflammatory drugs on the upper gastrointestinal tract.

This article reviews the clinical and epidemiological features of conventional non-steroidal anti-inflammatory drug (NSAID) related peptic ulcer complications, and the associated risk factors. The degree of gastrointestinal toxicity varies widely between the available drugs and with dose of each. The risk of ulcer complications can however be reduced, and perhaps completely removed, by using the lowest dose of the least toxic member of the class. Enteric coating and other delayed release formulations have not been shown to reduce risk. Estimates of the imposed disease burden have varied widely, in part through assuming that risks in selected patient groups will necessarily translate to the general population. Nevertheless, the imposed disease burden is one of the largest associated with current drug treatment. Associated risk factors such as prior ulcer, corticosteroid use and concurrent aspirin as well as general cardiovascular disease will raise the likelihood of an ulcer complication in NSAID takers and non-takers. Therefore, strategies dependent on substituting COX-selective drugs will then be only partially successful.

Phase III randomized trial assessing rofecoxib in the adjuvant setting of colorectal cancer: final results of the VICTOR trial.

PURPOSE: Laboratory and case-control studies suggest a pivotal role for the cyclooxygenase-2 (COX-2) pathway in colorectal carcinogenesis. The purpose of this study was to test whether the COX-2 inhibitor rofecoxib could reduce recurrence and improve survival when administered in the adjuvant setting of colorectal cancer (CRC). PATIENTS AND METHODS: Patients who had undergone potentially curative surgery and completion of adjuvant therapy for stage II and III CRC were randomly assigned to receive rofecoxib (20 mg daily) or placebo. The primary end point was overall survival (OS). Where formalin-fixed paraffin-embedded tumor tissue samples were available, COX-2 expression was evaluated by immunohistochemistry and correlated with clinical outcome. RESULTS: Two thousand four hundred thirty-four patients were entered onto the study. The trial was terminated early because of the worldwide withdrawal of rofecoxib. At this point, 1,167 patients had received rofecoxib and 1,160 patients had received placebo for median treatment durations of 7.4 and 8.2 months, respectively. For the rofecoxib and placebo arms, median follow-up times were 4.84 and 4.85 years, with 241 and 246 deaths and 297 and 329 recurrences, respectively. No difference was demonstrated in OS (hazard ratio [HR] = 0.97; 95% CI, 0.81 to 1.16; P = .75) or recurrence (HR = 0.89; 95% CI, 0.76 to 1.04; P = .15) comparing the two groups. Tumor COX-2 expression by immunohistochemistry was assessed for 871 patients, but neither prognostic nor predictive effects were observed. CONCLUSION: In this study of abbreviated therapy in the adjuvant setting of CRC, rofecoxib did not improve OS or protect from recurrence in unselected patients. In addition, COX-2 expression did not correlate with prognosis overall or predict effectiveness of COX-2 inhibitors.

Antihypertensive medication and the risk of acute pancreatitis: the European case-control study on drug-induced acute pancreatitis (EDIP).

OBJECTIVE: Angiotensin-converting enzyme (ACE) inhibitors and diuretics have been associated with acute pancreatitis. We quantified the risk of acute pancreatitis associated with the use of antihypertensive medication in the European study on drug-induced acute pancreatitis (EDIP). MATERIAL AND METHODS: The EDIP study is a multicenter population-based European case-control investigation of the association between drug use and acute pancreatitis. Patients between 40 and 85 years of age hospitalized for acute pancreatitis were included in the study between 1 October 1994 and 31 December 1998. For each case, age- and gender-matched community controls were recruited. Detailed information on drug use and potential confounders (e.g. comorbidity, alcohol use) was obtained through a structured interview. RESULTS: In all, 724 patients with acute pancreatitis and 1791 community controls were identified and interviewed. Use of ACE inhibitors in the week prior to the index date was associated with an increased risk of acute pancreatitis (adjusted odds ratio 1.5; 95% CI: 1.1-2.2). The risk of acute pancreatitis associated with ACE inhibitors increased with higher daily doses and was highest in the first 6 months of therapy. Calcium channel blockers increased the risk of acute pancreatitis (adjusted odds ratio 1.5; 95% CI: 1.1-2.1) without an apparent dose- or response relationship. Loop and thiazide diuretic use was not associated with an increased risk of acute pancreatitis. Potassium-sparing diuretics elevated the risk of acute pancreatitis, albeit non-significantly. CONCLUSION: Use of ACE inhibitors is associated with a modest increase in the risk of acute pancreatitis during the first months of treatment.

Protein kinase C inhibition induces DNA fragmentation in COLO 205 cells which is blocked by cysteine protease inhibition but not mediated through caspase-3.

Enhancing apoptosis to remove abnormal cells has potential in reversing cancerous processes. Caspase-3 activation generally accompanies apoptosis and its substrates include enzymes responsible for DNA fragmentation and isozymes of protein kinase C (PKC). Recent data, however, question its obligatory role in apoptosis. We have examined whether modulation of PKC activity induces apoptosis in COLO 205 cells and the role of caspase-3. Proliferation ([3H]thymidine) and apoptosis (DNA fragmentation and FACS) of COLO 205 cells were measured in response to PKC activation and inhibition. Caspase-3 activity was assayed and the effects of its inhibition with Ac-DEVD-cmk, and the effect of other protease inhibitors, on apoptosis were determined. PKC activation and inhibition both reduced DNA synthesis and induced DNA fragmentation. As PKC inhibitors induced DNA fragmentation more rapidly than PKC activators and failed to block activator effects, we conclude that it is PKC down-regulation (i.e., inhibition) after activator exposure that mediates apoptosis. Increases in caspase-3 activity occurred during apoptosis but apoptosis was not blocked by caspase inhibition. By contrast, the cysteine protease inhibitor, E-64d, blocked apoptosis. Cysteine proteases not of the caspase family may either act more closely to the apoptotic process than caspases or lie on an alternative, more active pathway.