TNFis Pose No Cancer Risk for Spondyloarthritis Patients

Patients with spondyloarthritis can confidently undergo treatment with tumor necrosis factor ⍺ inhibitors (TNFi) without fear of increasing their overall risk of cancer, a new study finds. Existing safety data is scarce, and cancer risks aren’t clearly understood.

According to a May 4 Annals of the Rheumatic Diseases  (ARD)  study from the Karolinska Institute in Sweden, patients who use TNFi to treat spondyloarthritis (SpA) have an equivalent overall cancer risk as those who have never received TNFi. There is also no increased risk for six site-specific cancers: prostate, lung, colorectal, breast, malignant lymphoma and melanoma.

Traditionally, TNFi is a standard part of treatment for chronic inflammatory disease, including rheumatological arthritis, SpA , ankylosing spondylitis (AS). psoriatic arthritis (PsA) and undifferentiatied spondyloarthritis (SpA UNS). The study aimed to evaluate the role TNFi plays in increasing cancer risk and how it could vary across inflammatory diseases by age, sex, lifestyle and previous treatments.

“Apart from the immediate clinical importance considering the increasing use of TNFi in SpA, the study of cancer risk in these patients may provide new insights different from RA cohorts,” researchers wrote. “Patients with SpA are younger, often male, have different lifestyles, frequently use biological DMARDs as monotherapy and have no intrinsic associations with, for example, malignant lymphoma.”

Researchers gathered data from the Swedish Anti-Rheumatic Therapy in Sweden (ARTIS) and Danish Biologic (DANBIO) registers. They included information on 8,703 SpA patients (ARTIS=5,448; DANBIO=3,255) who used TNFi treatments for the first time between 2001 and 2011. They also gathered data on 28,164 SpA patients who never used TNFi for the Swedish National Patient and Population Registers. In addition, 131,687 patients from the general population were included for comparison.  [[{"type":"media","view_mode":"media_crop","fid":"48886","attributes":{"alt":"©PhuShutter/Shutterstock.com","class":"media-image media-image-right","id":"media_crop_6372886681276","media_crop_h":"0","media_crop_image_style":"-1","media_crop_instance":"5868","media_crop_rotate":"0","media_crop_scale_h":"0","media_crop_scale_w":"0","media_crop_w":"0","media_crop_x":"0","media_crop_y":"0","style":"font-size: 13.008px; line-height: 1.538em; float: right;","title":"©PhuShutter/Shutterstock.com","typeof":"foaf:Image"}}]]

Based on their results, out of 1,188 cancers, among SpA patients who never used TNFis, the relative risk of cancer overall was 1.1 (95% CI 1.0 to 1.2). The 147 cancers among SpA TNFi users showed an relative risk ratio of 0.8 versus TNFi-naïve patients (95% CI 0.7 to 1.0). The results were similar to AS and PsA when analyzed separately. Site-specific RRS were: prostate, 0.5 (95% CI 0.3 to 0.8), lung, 0.6 (95% CI 0.3 to 1.3), colorectal, 1.0 (95% CI 0.5 to 2.0), breast, 1.3 (95% CI 0.9 to 2.0), lymphoma, 0.8 (95% CI 0.4 to 1.8), and melanoma, 1.4 (95% CI 0.7 to 2.6).

Although the study represents the largest assessment of cancer risk after TNFi therapy in patients with SpA to date, there were some limitations to the study, such as the time span which may not have been long enough to detect effects of TNFi therapy that may occur years after exposure.

References:

Karin Hellgren, Lene Dreyer, et al.

"Cancer risk in patients with spondyloarthritis treated with TNF inhibitors: a collaborative study from the ARTIS and DANBIO registers,"

Annals of the Rheumatic Diseases.

May 4, 2016.