Marion B.
Tue Mar 26, 5:52 AM ET 2002
LONDON (Reuters) - Prozac and related antidepressants could in theory increase the risk of brain cancer by preventing the body´s innate ability to kill tumor cells, a British researcher said Tuesday.
Professor John Gordon of Birmingham University reported that Prozac and other selective serotonin reuptake inhibitors (SSRIs) encouraged growth of a type of cancer called Burkitt´s lymphoma in test-tube experiments.
While there is no evidence from clinical trials on people to back up the concerns, the finding is likely to reopen controversy about the widespread use of the class of antidepressants that first went on sale in the 1980s.
Millions of people with depression and anxiety have been prescribed the drugs, which have emerged as one of the biggest sellers for the international pharmaceutical industry.
Gordon, whose findings were published in the online edition of the medical journal Blood, said serotonin was a key driver in stimulating apoptosis, a natural cell "suicide" process for controlling the runaway growth that leads to cancer.
SSRIs such as Eli Lilly and Co.´s Prozac, Glaxo SmithKline Plc´s Paxil and Lundbeck´s Celexa, however, appear to block this action.
Drug company officials said there was no evidence that their pills caused any increase of cancer in practice and questioned whether the high doses used in Gordon´s experiments may have been responsible for the results.
"These data are from an in vitro (test tube) study and as such they cannot be extrapolated to a clinical setting with any degree of certainty," said Martin Sutton, a spokesman for GSK.
Paxil, which is also known as Seroxat, has overtaken Prozac as the world´s best-selling SSRI with worldwide sales last year of $2.7 billion.