Arthritis drug cancer risk downgraded
Researchers have downgraded the reported cancer risks associated with two rheumatoid arthritis drugs.
While the researchers said that adalimumab and infliximab may still increase the risk of cancer, they do so less than the three-fold risk increase reported earlier this year.
The drugs remained in use but US regulators had insisted that the accompanying user notes informed patients of the risk.
Several teams in the US had been looking at the drugs and the original team who warned of the link reassessed their research following correspondence in medical journals.
"We re-did the analysis completely," Dr Eric Matteson of the Mayo Clinic in New York told Reuters, adding that cancer risks rose 2.4 per cent among people using the drugs.
"The magnitude is still higher in treated groups than in untreated groups. Anything that modifies our immune systems does have the potential for causing cancers."
Rheumatoid arthritis causes the immune system to attack joints. Both drugs counter this by altering the ways that immune system cells communicate with each other.
The drugs also increase the risk of infectious diseases such as tuberculosis by a factor of 1.8 per cent, said the Mayo Clinic team.