CANCER recurrence after TNF inhibitor (TNFi) treatment in rheumatoid arthritis (RA) patients with a history of solid cancer was no greater than in a similar group of patients who were not treated with TNFi, based on the results of a Swedish-based cohort study.
This study was designed using data obtained from Swedish cancer and RA registries. Patients with RA who had initiated TNFi treatment between 2001 and 2015 and had a previous diagnosis of a solid cancer were matched with similar patients who were biologic-naïve. Four groups of patients were included in the study and used to compare the cancer recurrence rates of different patients:
- Group A compared 467 patients with RA that had received TNFi treatment with 2,164 RA patients who had not received TNFi treatment, with an adjusted hazard ratio (HR) for first cancer recurrence of 1.06 (95% confidence interval [CI]: 0.73–1.54; 9.0% versus 7.2%, respectively).
- Group B utilised the cancer recurrence rate of 223 cancer patients that had received TNFi treatment compared to a matched group of 1,070 biologic-naïve patients, with an adjusted HR for first cancer recurrence of 1.08 (95% CI: 0.65–1.80; 10.0% versus 7.3%, respectively).
- Group C included 138 patients that had received TNFi treatment matched with 649 biologic-naïve patients with index cancers that had been diagnosed from 2003–2015, with an adjusted HR of 1.15 (95% CI: 0.53–2.47; 12% versus 6%, respectively).
- The final group, Group D, was an unmatched analysis. Out of a cohort of 3,826 patients with RA who were biologic-naïve and had been diagnosed with a solid cancer between 2001 and 2015, 178 initiated TNFi treatment after their inclusion in the study. The outcomes of the 178 patients were compared with the outcomes of the remaining patients; the adjusted HR was 1.24 (95% CI: 0.74–2.07; 5% versus 9%, respectively).
These findings highlight precisely why continued investigation and follow-up of patients treated with biologics is so vital for the medical community to fully understanding the implications of biological treatment, not only in the initial stages, but also long term. Although this research built on previous work to suggest that there was not an association between TNFi treatment and cancer recurrence, the researchers nonetheless urged caution when interpreting these results. The authors also noted that their results might not directly apply to several patient groups: those with cancer types other than solid, those with ongoing cancer, and those with a recent cancer diagnosis.
