Having rheumatoid arthritis could significantly lower the life expectancy of elderly patients with certain kinds of cancer, according to a recent study led by a researcher from the School of Public Health at Georgia State University.
[Photo: Dr. Pratibha Nayak]
The study used a Texas-based cancer registry linked to Medicare claims data to identify more than 139,000 elderly patients who had been diagnosed with breast, prostate, colorectal or lung cancer between 2001 to 2010 and analyze the effect of rheumatoid arthritis (RA) on their survival.
The results are published in Arthritis Care & Research in an article titled “Impact of Rheumatoid Arthritis on the Mortality of Elderly Patients who Develop Cancer: A Population-Based Study.” The study’s lead author is Dr. Pratibha Nayak, a postdoctoral research associate at the School of Public Health.
Patients with rheumatoid arthritis are at greater risk for developing certain cancers, likely because of shared genetic or environmental factors, the effects of long-term inflammation, and the use of drugs to treat RA that affect the immune system, the article noted. However, “few studies have evaluated the independent effect of RA on the overall survival of cancer patients.”
The median survival rates for patients with breast or prostate cancer who also had rheumatoid arthritis were roughly two years shorter than for patients who did not have RA (7.1 years versus 9.5 years for breast cancer patients and 7.3 years versus 9.8 years for prostate cancer patients), according to the study results.
The results also showed a small, statistically insignificant risk for patients with colorectal cancer and RA. The researchers observed no differences for patients with lung cancer and RA.
“These findings suggest the additional cancer mortality risk from having RA is more pronounced for those tumors with longer expected medial survival,” the study stated. “These differences persisted after controlling for age, gender, ethnicity, surrogate socioeconomic status, tumor stage, and other comorbidities.”
The study’s authors also included Drs. Ruili Luo, Linda Elting, Hui Zhao and Maria E. Suarez-Almazor of the MD Anderson Cancer Center at the University of Texas.