Patients taking biologic medications to relieve neck pain and other symptoms of Rheumatoid arthritis may be relieved to hear that these powerful drugs do not appear to increase the short term risk of cancer, according to a new study.
The comprehensive meta-analysis carried out by researchers at The University of Texas MD Anderson Cancer Center in Houston was published in the Journal of the American Medical Association (JAMA) this week and is expected to allay fears over the possible increased cancer risk in patients with RA who take any of the nine US FDA approved biologic response modifiers, such as abatacept and rituximab.
Rheumatoid Arthritis Symptoms and Treatment
Rheumatoid arthritis is an autoimmune condition that is thought to cause such symptoms as joint pain, fever, fatigue and even mood disturbances in some. Unlike the type of arthritis caused by wear and tear, Rheumatoid arthritis can strike young and old, regardless of physical stresses on the joints. Joint pain is usually symmetrical in cases of RA, whereas osteoarthritis often appears asymmetrically as some joints bear the brunt of daily exertions. Neck pain connected to RA may lead to spinal slippage and pinched nerves or spinal cord compression, which is why early treatment with biologic response modifiers can be so helpful in relieving pain and slowing the disease’s progression.
DMARDs for RA
As reported recently, black patients in the US appear less likely to be taking disease modifying anti-rheumatic drugs (DMARDs) than their white or Hispanic counterparts. Whether this finding is due to discrimination or some other factor, there are those who may have considered this lower level of use a good thing considering persistent concerns over the risk of cancer when taking such drugs. However, those on the following medications were found not to have an increased propensity for the development of new malignancies in the short-term:
- abatacept (Orencia)
- adalimumab (Humira)
- anakinra (Kineret)
- certolizumab (Cimzia)
- etanercept (Enbrel)
- golimumab (Zimponi)
- infliximab (Remicade)
- rituximab (Rituxan)
- tocilizumab (Actemra)
Cancer in RA Patients Taking BRMs
Dr. Maria E. Suarez-Almazor, who led the research team, said the findings should be “reassuring for patients with rheumatoid arthritis who might be concerned about developing cancer if they are treated with biologic agents.” Previous studies and meta-analyses have looked at the rate of malignancy in those with RA and other conditions who were taking biologic drugs, but this is the first time that cancer risk has been assessed in patients with RA alone.
Methotrexate, Biologics and Arthritis
No statistically significant increased risk of developing cancer with biologic response modifiers was found amongst the nearly thirty thousand patients included in the analysis. During the trial there were 211 malignancies that did develop, including 118 solid tumors, 48 skin cancers, 14 lymphomas, 5 hematologic non-lymphomas, and 26 which were not described. This works out to an incidence rate for the development of any malignancy in the first year of Rheumatoid arthritis therapy using BRMs alone of 0.64%. When BRMs were taken with methotrexate the incidence rate was 0.77% and the control group has an incidence rate of 0.66%. Interestingly, those using anakinra alongside methotrexate had lower rates of malignancy than those using methotrexate alone.
Lymphoma Rates for RA Patients on Biologics
The researchers note that there needs to be longer-term studies done to assess the effects of continued treatment with biologic response modifiers for RA. This meta-analysis including both shorter and longer duration studies but most had a follow-up of one year. In terms of risk for different types of cancer, there were no statistically significant risks except for lymphoma which had an odds ratio of 2.1 in patients taking tumor necrosis factor inhibitors compared to controls. The US Food and Drug Administration (FDA) have, themselves, recommended a warning label be added to these TNF inhibitors because of increase in cases of spontaneous lymphoma in children and adolescents entered into the Adverse Event Reporting System database.
Long-Term Studies Needed
This latest meta-analysis does not provide data for the incidence of recurrent cancer in those patients with RA and a history of cancer or those with cancer risk factors. Different types of cancer arise in different ways and so some physicians have pointed out that it is also important to study the relationship between certain risk factors for cancer, the use of particular biologic response modifiers for RA and the incidence of malignancy. Whilst this latest meta-analysis gives cause for relief for many of those taking biologic medications to treat neck pain and other symptoms of Rheumatoid arthritis, or autoimmune condition such as ankylosing spondylitis, it also acknowledges a deficit in knowledge. To close this gap there needs to be continued monitoring of the longer-term incidence of cancer connected to the use of biologic response modifiers for RA.
Lopez-Olivo, M.A., et al, Risk of Malignancies in Patients With Rheumatoid Arthritis Treated With Biologic Therapy: A Meta-analysis, JAMA, September 5, 2012, Vol 308, No. 9