Kenzik KM, et al. - In older patients with colorectal cancer, researchers examined the long-term risk of cardiovascular disease (CVD)—stroke and myocardial infarction—and congestive heart failure (CHF). In addition, they investigated if preexisting comorbidities and cancer therapy play a role in increasing this risk. An increased risk of developing CVD and CHF was observed among these patients. An interaction of diabetes and hypertension with chemotherapy increased the risk of cardiovascular morbidity.

Methods

• From January 1, 2000 to December 31, 2011, individuals from the SEER-Medicare database with incident stage I to III colorectal cancer at age older than 65 years (n = 72,408) were evaluated.
• Researchers performed a comparison of these patients with a matched cohort of Medicare patients without cancer (n = 72,408).

Results

• At diagnosis of colorectal cancer, median age was 78 years (range, 66 years to 106 years), and since diagnosis, median follow-up was 8 years.
• The new-onset CVD and CHF showed a 10-year cumulative incidence of 57.4% and 54.5% compared with 22% and 18% for control, respectively (P < .001).
• Significant interaction between hypertension and chemotherapy was observed (P < .001) for CVD, and between diabetes and chemotherapy was observed (P < .001) for CHF.
• Exposure to capecitabine alone increased CHF hazard (hazard ratio [HR], 3.6; 95% CI, 12.76 to 4.38) compared with exposure to fluorouracil alone within the first 2 years since diagnosis.
• Conversely, at < 2 years and > 2 years since diagnosis, patients who were treated with fluorouracil alone had a higher CVD hazard compared with patients who received capecitabine alone (< 2 years HR, 0.63; 95% CI, 0.53 to 0.75; > 2 years HR, 0.72; 95% CI, 0.62 to 0.84).