Another Study Shows No Malignancy after Biologics

A newly published small prospective observational study shows that rheumatoid arthritis patients who have had a malignancy and are receiving a TNFi or rituximab (RTX), do not appear to have an increased risk of cancer recurrence.

Chronic inflammation, such as inflammation associated with rheumatoid arthritis, has been shown to predispose patients to cancer. It leads to increased cell proliferation, mutagenesis, oncogene activation and angiogenesis. “The longer the inflammation persists, the higher the risk of associated carcinogenesis,” in particular, lymphoma, leukemia and lung cancer, write the authors of a study published in the Aug. 22 online issue of Rheumatology.

The study, led by Kimme L. Hyrich, Ph.D., of the University of Manchester, U.K., explores the influence of rituximab on the incidence of cancer in patients with rheumatoid arthritis and a prior malignancy.

Hyrich and colleagues identified 425 patients with a prior malignancy from 18,000 rheumatoid arthritis patients. Of these, 101 patients developed a new malignancy. The rates of incident malignancy were 33.3 events/1,000 person years in the TNFi cohort; 24.7 events/1,000 person years in the rituximab group and 53.8 events/1,000 person years in the DMARD group. 17.0% of patients in the DMARDs group had a recurrence of the same cancer as compared to the 12.8% and the 4.3% in the TNFi and rituximab groups, respectively.

The authors compared the rates of first incident malignancies that were diagnosed after the first dose of the biologic agent or after the study registration date for the sDMARDs group. They found that after five years, patients with rheumatoid arthritis and a prior malignancy who received TNFi or rituximab treatment, did not seem to have an increased risk of recurrence or develop a new malignancy.

How this study add to our current knowledge about biologics and cancer risk:

The current findings are consistent with previous findings in which patients with a prior malignancy, who were on TNFi therapy, did not have an increased risk of cancer recurrence. The current study extends the mean follow-up by three years.

“Nevertheless, attending to the wide confidence interval of the HR in the RTX group, we cannot firmly rule out a clinically important increased or decreased risk of IM in patients receiving RTX,” the authors wrote.

Limitations

Although this was among the largest and longest studies to address the question of cancer risk in this group of patients, the authors cited a number of concerns, including the non-randomization of treatment in the study which could threaten the validity of the results.

The authors suggest that the results be “interpreted in the context of an observational study of routine clinical practice.”

References:

Silva-Fernandez L, Lunt M, Kearsley-Fleet L, et al. “The incidence of cancer in patients with rheumatoid arthritis and a prior malignancy who receive TNF inhibitors or rituximab: results from the British Society for Rheumatology Biologics Register-Rheumatoid Arthritis.” Rheumatology. Published online Aug. 22, 2016. DOI:  10.1093/rheumatology/kew314

Dixon WG, Watson KD, Lunt M et al. “Influence of anti-tumor necrosis factor therapy on cancer incidence in patients with rheumatoid arthritis who have had a prior malignancy: results from the British Society for Rheumatology Biologics Register,” Arthritis Care and Research. 2010;62:755[1]63.