New research suggests that biological therapies (biologics) do not increase the risk of recurrent cancer compared to conventional disease modifying anti-rheumatic drugs (DMARDs). The study, which will be presented at Rheumatology 2014, analysed data from almost 19,000 patients with rheumatoid arthritis.
The research examined the relationship between treatment type and new cancer cases in patients with rheumatoid arthritis who had previously had cancer. It compared patients taking biologics with those who had never taken these drugs. The number of new cancer cases was lower in patients taking biologics, with an age- and gender-adjusted hazard ratio of 0.47 for those receiving rituximab and 0.55 for those receiving anti-TNF, compared to those taking conventional DMARDs.
Both biologics (such as rituximab and anti-TNF) and conventional DMARDs (including methotrexate and sulfasalazine) are used in the treatment of rheumatoid arthritis. They target the underlying causes of rheumatoid arthritis, slowing disease progression to reduce pain, swelling and stiffness. While conventional DMARDs are slow-acting, the newer biological therapies act quickly and target individual molecules.
However, there have been concerns that treatment with biologics can increase the risk of cancer recurring in patients who have previously had cancer.
The team used data from the British Society for Rheumatology Biologics Register for rheumatoid arthritis (BSRBR-RA), examining data from almost 19,000 patients between 2001 and 2013. Using the NHS information centre (NHS-IC) they found that 425 patients within this group had had cancer before they registered with the BSRBR-RA. These patients were monitored using questionnaires to identify their treatment and via the NHS-IC to see whether they later developed another cancer.
In addition to the low hazard ratios for biologic drugs, the research found that those previously diagnosed with cancer were prescribed rituximab much earlier than anti-TNF. The median average time from most recent prior malignancy to the first dose of biologic was 5.4 years for patients taking rituximab and 11.5 years for those taking anti-TNF. This is potentially because rituximab is considered safer for these patients, because it is also used as a cancer treatment in lymphoma.
Lead researcher Lucia Silva-Fernandez said: "The exact relationship between biologics and cancer in patients with rheumatoid arthritis remains unclear. We have seen that patients with rheumatoid arthritis and a prior malignancy selected to receive a biologic in the UK do not have an increased risk of overall cancer recurrence in comparison with biologic-naïve patients. Nevertheless, additional research on specific types of cancer needs to be conducted to further understand the links between biologics and cancer."
President of the British Society for Rheumatology Dr Chris Deighton said: "This is extremely helpful information that we can share with patients in order to help them make evidence-based decisions when it comes to agreeing a management plan. It is essential that we continue to monitor the safety profile of biological therapies, because some of our younger patients may be on them for literally decades. The long-term follow-up that has been conducted so far is very reassuring regarding the risk of cancer, even in patients who have previously had this disease."
Manager of the British Society for Rheumatology Biologics Register Dr Alan Roach said: "The BSR Biologics Register has now recruited over 22,000 patients, some of whom we have now been tracking for over ten years. This makes the register a rich resource for researchers to analyse the effects of biologics and increase our understanding of them, ultimately for the benefit of patients."
The research "The influence of anti-TNF or rituximab on cancer incidence in patients with rheumatoid arthritis who have had prior malignancy" from Lucia Silva-Fernandez et al will be presented at Rheumatology 2014 as an oral abstract within the Rheumatoid Arthritis session on Wednesday 30 April from 9 - 10.30am.