American College of Cardiology (ACC) 61st Annual Scientific Session & Expo: Page 2 of 2

May 15, 2012

Epidemiologic Study Finds Link Between Atrial Fibrillation and Cancer in Older Adults

Incident cancer is more likely in patients 65 years and older who are hospitalized for atrial fibrillation (AF), compared with the general population, according to Italian researchers, who presented their finding during a poster session at the ACC 61st Annual Scientific Session & Expo. The authors hypothesized that AF is linked to noncardiac diseases because patients with AF have demonstrated features of chronic inflammation. In the AFFIRM (Atrial Fibrillation Follow-up Investigation of Rhythm Management) study, an AF management strategy of rhythm control conferred no advantage over rate control on cardiac mortality or vascular mortality, but rhythm control was associated with an increase in the rate of noncardiovascular death, mainly attributable to pulmonary diseases and cancer (Circulation. 2004[16];109:1973-1980).

The Italian researchers analyzed the relationship between AF and cancer, identifying all patients hospitalized for AF between 2005 and 2007 in Florence, Italy. Prevalent cases of cancer were identified using the Tuscany Cancer Registry. Excluded from the analysis were persons who experienced an episode of AF or cancer in the previous 5 years.

The incidence of cancer was ascertained using the Tuscany Inpatient Registry, with further validation from the Tuscany Cancer Registry. Cases of prostate cancer and skin neoplasms other than melanoma were excluded from the analysis. Follow-up was closed in 2010. The standardized incidence ratio (SIR), which is the ratio between the observed and the expected number of cases of malignancies, was estimated for all new cases of cancer. Expected cases were computed using age- and sex-adjusted incidence rates of neoplastic disease.

Between 2005 and 2007, AF was recorded during 16,986 hospital admissions. In 4270 of those, AF was the primary diagnosis. Because some patients were hospitalized for AF more than once, the total number of subjects enrolled was 3323, and after exclusion of those with a history of cancer or with incomplete data, there were 1843 remaining for analysis.

Among the 1843 patients, 133 cases of cancer were identified in patients with AF, compared with an expected incidence of 88 (SIR, 1.51; P<.001). The incidence of cancer was significantly greater for both men and women with AF compared with their counterparts in the general population without AF. An analysis by age demonstrated that the influence of AF on the development of cancer became evident in subjects 65 years and older, a trend that was evident in both men and women. Stomach, kidney, and brain cancers were the most common cancers observed in the AF population.—Wayne Kuznar