Consider The Evidence: Med/Peds Journal Roundup

September 4, 2006

Revenge of the COX-2 inhibitors ?

Filed under: cancer, NEJM — medblog @ 8:30 pm

NEJM 8/31 – Results of the VIGOR trial in 2001 shook the medical world with controversy as concern over cardiovascular side effects pushed several COX-2 drugs off the market. Cox-2’s were not only interesting for their anti-inflammatory effect, but also due to evidence of protection from colorectal adenomas – the precursor to colorectal cancer. But studies by both Pfizer and Merck regarding this effect ground to a halt after safety concerns sufaced.

A pair of articles by M. M. Bertagnolli et al. and N. Arber et al. in the New England present data on the prevention of colorectal polyps and adenomas with Celecoxib. Both studies were RCT’s in which the subjects had previous adenomatous lesions removed.

Bertagnolli’s RCT followed over 1800 patients from 1-3 years and compared high and low dose celecoxib therapy to placebo. They found a signficant 33% and 45% risk reduction for the formation of colorectal ademonas with the two groups respectively. The downside was that the risk of cardiovascular effects was 2.6 and 3.4 times higher in the celecoxib groups.

The Arber et al. study had similar results with a 46% risk reduction in adenomas and a 50% risk reduction in advanced adenomas. Serious cardiovascular events occurred in 2.5 percent of subjects in the celecoxib group and 1.9 percent of those in the placebo group (relative risk, 1.30).

Many questions remain about COX-2 inhibitors. Some recent data suggests that these drugs are just as dangerous as non-selective NSAIDs. Also the relative risk of harm varies from 1.3 in the Arber studies to 4 in the VIGOR trial. Hopefully the full story will become clear with further research…


April 17, 2006

Call me on my (benign) Cell

Filed under: BMJ, cancer, Uncategorized — medblog @ 12:34 pm

BMJ 4/15 – Hepworth et al. weigh in on the cell phone / brain tumor controversy with a case- control study. Some (poorly interpreted) studies have shown some correlation, so I'm sure this won't end the controversy. Frankly, I'm amazed that they found enough non-cell phone users to do the study. The study compared about a thousand glioma patients with seventeen hundred controls. The cases were matched by age, sex, and geography. All patients were interviewed about the frequency and duration of cell phone use. They conclude "There is generally a lack of convincing and consistent evidence of any effect of exposure to radiofrequency field on risk of cancer…" The group also commented on the fact that their study also found a increased risk in relation to side of use despite an unchanged overall risk – "this finding is probably explained by recall bias, with patients with glioma systematically over-reporting use on the same side as their tumour and consequently under-reporting use on the opposite side." Ambidexterity finally has a downside…

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