Scott Hensley is one of the country’s best health care reporters and his article on the risks and benefits of drugs for RA proves it. Scott’s piece is fairly balanced, however as I noted in an email to him: Not bad as far as most pieces of this genre…but if you had delineated between cancers and put this study into the context of other similar projects if would have made people rest easy rather than give the Grassleys and Sid Wolfes of the world more red meat for slowing down drug development.
For instance, ” Patients with rheumatoid arthritis (RA) are at increased risk of lymphoma, and standardised incidence ratio (SIR) is greatest for those treated with anti-tumour necrosis factor (anti-TNF) therapies; however, differences between therapies are slight, and data are insufficient to establish a causal relationship between RA treatments and the development of lymphoma, a new report indicates.
It has previously been reported that methotrexate (MTX) and anti-TNF therapies might be independently associated with an increased risk of lymphoma. However, small sample sizes and selected study populations in these studies could not confirm this association.
To investigate this issue further, Frederick Wolfe, MD, and Kaleb Michaud, MS, with the National Data Bank for Rheumatic Diseases, Arthritis Research Foundation, in Wichita, Kansas, United States, prospectively studied 18 572 enrolees in the National Data Bank for Rheumatic Diseases (NDB).
Patients were surveyed twice a year. Reported cases of potential lymphoma were further investigated. The expected number of cases of lymphoma was determined by using data from the Survey, Epidemiology, and End Results (SEER) cancer data resource.
Overall, 88 lymphomas were identified, 59 of which occurred prior to NDB enrolment and 29 of which occurred after NDB enrolment and during the period of intensive follow up.
The overall SIR for lymphoma, regardless of treatment, was 1.9. For patients receiving biologics, SIR was 2.9 (95% CI 1.7-4.9). For those taking infliximab, with or without etanercept, the SIR was 2.6 (95% CI 1.4-4.5). For etanercept, with or without infliximab, the SIR was 3.8 (95% CI 1.9-7.5). The SIR for MTX was 1.7 (95% CI 0.9-3.2), and for those not receiving MTX or biologics, the SIR was 1.0 (95% CI 0.4-2.5).
Lymphoma was associated with increasing age, male sex, level of education, and comorbidities. The Cox regression hazard ratios and 95% CIs for these variables were 1.58 per 10-year increase in age (95% CI 1.16-2.18); 3.70 (95% CI 1.79-7.68) for male sex; 1.16 (95% CI 0.99-1.37) for education; abd 1.30 (95% CI 1.10-1.54) and for comorbidity.
“The results of this study show that lymphoma is increased in RA compared with the general population,” Dr. Wolfe and colleagues conclude. However, even a sample of more than 18 500 patients could not demonstrate significant differences among the studied groups, because of the rarity of lymphoma, they note.
“It seems possible that the apparently increased rates of lymphoma are, in fact, reduced by therapy, and that the ‘increase’ may reflect channelling bias whereby patients with the highest risk of lymphoma preferentially receive anti-TNF therapy,” the researchers conclude.
“It appears that neither clinical trial data nor data from the current study are sufficient to establish a causal relationship between RA treatments and the development of lymphoma,” they add.
Arthritis Rheum 2004;50:1740-1751. “Lymphoma in rheumatoid arthritis: The effect of methotrexate and anti-tumor necrosis factor therapy in 18,572 patients”
There is also this study http://www.arthritis-research.org/Documents/breast_ca_ACR2005.ppt
and this one http://www.arthritis-research.org/Documents/lung%20cancer_ACR2005.ppt
PS. The fact that drug companies support research does not make the research wrong. If that were the case, then no drug would work since all research submitted to the FDA is done by drug companies…