November 22, 2005

CORRECTION: Heavy antibiotic linked to increased lymphoma

Recasts headline, and clarifies that infection rather than
antibiotics per se may raise NHL risk.

NEW YORK (Reuters Health) - Using antibiotics more than 10
times during adulthood is associated with an increased
likelihood of developing non-Hodgkin's lymphoma (NHL), a cancer
that affects the body's lymphatic system, new research

The researchers believe, however, that heavy antibiotic use
is a marker of increased susceptibility to infection, and it is
probably this rather than antibiotics themselves that gives
rise to the increased lymphoma risk.

Dr. Ellen T. Chang of the Northern California Cancer Center
in Fremont and her colleagues also found a marginally increased
NHL risk among heavy users of non-steroidal anti-inflammatory
drugs (NSAIDs), such as ibuprofen (Motrin, Advil), but no
association between the disease and any other types of

Given the rising incidence of NHL, Chang and her team note
in the American Journal of Epidemiology, a number of studies
have investigated whether certain medications increase the risk
of the disease. But results have been inconclusive, with only
strong immunosuppressive drugs consistently being tied to NHL.
Because a number of medical conditions also may be associated
with NHL, they add, the question of whether the drug or the
underlying condition is involved has complicated matters

To investigate, the researchers looked at data from the
Scandinavian Lymphoma Etiology study, which included 3,055
patients with NHL who were compared with 3187 healthy subjects
drawn from Danish and Swedish population registers.

The "striking" association between antibiotic use and NHL
was seen for all subtypes of the disease. High NSAID use
increased overall risk of NHL and of diffuse large B-cell NHL,
but did not increase the likelihood of any other type of NHL.

The increasing use of antibiotics in the 20th century could
explain the rise in NHL cases, if the drugs are in fact
responsible for the association observed, Chang and her
colleagues note. However, they add, their study was unable to
determine if antibiotics and NSAIDs affected risk apart from
the underlying inflammation, infections or susceptibility to

There could be "a direct pathogenetic effect of antibiotics
on lymphoma development," they say, but "Biologic data more
strongly support the hypothesis that antibiotic use is an
indicator of infection and consequent inflammation, which may
increase the risk of NHL, and that high cumulative NSAID use is
a marker of chronic inflammation."

SOURCE: American Journal of Epidemiology, November 15,