麻豆传媒

MADRID -- Patients undergoing treatment for psoriatic arthritis who used anti-tumor necrosis factor (TNF) drugs were not at greater risk for developing cancers compared with the general Scandinavian public, researchers said here.

Presenting the results of a retrospective study using health records in four Nordic countries in Europe, Lene Dreyer, MD, of the University of Aalborg in Denmark, said that the number of cancers her team had expected to see was 281.6 and what they observed was 282 cancers -- a standardized incident ratio of 1.00 (95% CI 0.89-1.13) -- that is, no statistical difference.

In a press conference at the annual European Congress of Rheumatology, sponsored by the (EULAR), Dreyer explained that she and her colleagues examined the records of 5,218 patients from Sweden, 2,036 from Denmark, 526 from Finland, and 270 from Iceland.

When the team looked at individual cancer types, the only indicator that one form of the disease was associated with patients on anti-TNF drugs was lymphoma. In the pooled data that she presented, the standardized incident ratio for lymphoma was 1.84 (95% CI 1.20-2.82), which is statistically significant. But Dreyer told 麻豆传媒 that people with rheumatoid arthritis and psoriatic arthritis are known to have higher rates of lymphoma, believed to be the result of the inflammatory state of the diseases and not due to the drug.

Her assessment was supported by the moderator of the press conference where she discussed the study, Johannes Bijlsma, MD, of the University of Utrecht in the Netherlands, who suggested that it was time to put to bed the issue of whether drugs such as infliximab (Remicade), etanercept (Enbrel), and adalimumab (Humira) cause excess cancer in psoriatic arthritis patients.

"We have been using these drugs for more than 20 years in these patients and have millions and millions of patient-years of use and we have no evidence that they are associated with cancer," he told 麻豆传媒. "Personally I think we can stop searching now for this connection to cancer, because by bringing it up again and again you keep people worried about it."

The worry stems from the drugs' name, Dreyer suggested: If the agent inhibits tumor necrosis, whether it limits the patient's ability to fight cancer is the root of the concern, she said.

And her research suggests it is not a problem: "We observed no increased incidence of cancer among psoriatic arthritis patients treated with TNF-inhibitors compared to rates of the general public," she said. "I think it is very reassuring here that we have no signal of an increased cancer risk with these drugs."

In the study, the team identified adult patients diagnosed with psoriatic arthritis and who began treatment with the anti-TNF disease-modifying drugs from 2001 through 2014. The analysis included patients in national cancer registries who developed their first primary cancer other than non-melanoma skin cancer. The investigators determined each patient's first treatment with a TNFα-inhibitor and followed the patients until their first cancer was noted, the patient's death, or the patient's emigration through the end of 2014.

About 46% of the population from Denmark were men; 54% from Finland were men; 40% from Iceland were men, and 50% from Sweden were men. The mean age for the patients across the four countries was 48.

For the standardized incident rate of cancer, Dreyer said that there were no statistical differences in overall cancer rates by country: In Denmark, the standardized incident rate was 0.99. Finland had an increase of about 28% in excess cancers, but still was nonsignificant. In Iceland, there was a 70% greater risk of cancer with patients taking the TNF-inhibitors, but again, this figure didn't approach statistical significance. And in Sweden there was a 6% protective effect. The larger populations of Denmark and Sweden in the study more than offset the findings from Finland and Iceland, Dreyer said.

The pooled data hinted at an increased risk of colorectal cancer with anti-TNF therapy, but the 21% increased risk was not statistically significant, she added.

For lung cancer, the effect was the opposite, with anti-TNF therapy associated with a 21% protective effect, but this finding was not statistically significant either. For prostate cancer, there was a 30% protective effect of anti-TNF therapy, with borderline significance, Dreyer reported: a standardized incidence ratio of 0.70 (95% CI 0.50-0.98).

There appeared to be a 20% additional risk of breast cancer, but that too was not a significant finding, she said.

"TNF inhibitors have a well-established efficacy and safety profile in patients with psoriatic arthritis and we welcome these data which contribute to our understanding in the complex area of cancer risk," said Bijlsma.

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