Session Type: Abstract Submissions (ACR)
Comorbidity among cancer patients imposes additional risks for premature mortality. The specific effect of rheumatoid arthritis (RA) on survival among cancer patients is unknown. Our objective was to examine survival among cancer patients diagnosed with RA compared to patients without RA.
Patients diagnosed with colorectal, breast, prostate or non-small cell lung cancer between years 2001 to 2010 were identified from the Texas Cancer Registry and Medicare-linked databases, which includes all beneficiaries in Texas 65 years and older who develop cancer. Patients were divided into 3 groups on the basis of previous Medicare claims for RA (International Classification of Diseases, ICD-9 code 714): (i) those who had no hospital or outpatient Medicare RA (No RA); (ii) those who had at least one claim related to RA (1-RA), and those who had at least 2 – claims related to RA that occurred a minimum of 6 months apart (2-RA). The overall survival and 95% confidence intervals (95% CIs) were estimated for each of the cancer types (colorectal, breast, prostate and non-small cell lung), and compared between RA and no RA groups. Cox proportional hazards regression models were used to control for demographic factors, cancer stage, and other comorbid conditions. Comorbidity was evaluated using the Charlson’s comorbidity index.
The overall analytical sample consisted of 126,241 cancer patients, with a mean age of 75 years (breast 31,545; prostate 38,858; colorectal 27,784; non-small cell lung 28,054). About 1.7% (n=2,095) had 1-RA claim and 1.1% (n=1,397) 2-RA claims. After adjusting for covariates, the hazard ratios for patients in the 2-RA group were 1.42 (95% CI, 1.20–1.68) for those with breast cancer, and 1.45 (95% CI, 1.16-1.80) among those with prostate cancer. Increased mortality risk was observed among patients with colorectal cancer 1.17 (95% CI, 0.996-1.36) with 2-RA to those without RA, however this was not statistical significant (p value, 0.056). No differences in survival were observed between patients with or without RA and non-small cell lung cancer, and survival in patients with this tumor was much shorter than for the other 3 cancers.
A 40% increase in mortality was found among patients with breast or prostate cancer who also had RA, compared to those without RA. Additional research is needed to determine whether the observed increases mortality risk is related to comorbid burden, or differential utilization of cancer or rheumatoid therapies in patients with both diseases.
M. E. Suarez-Almazor,
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ACR Meeting Abstracts - https://acrabstracts.org/abstract/impact-of-rheumatoid-arthritis-on-the-mortality-of-patients-who-develop-cancer-a-population-based-study/