Risk of CVD Varies Among Adult-Onset Cancer Survivors

Some adult-onset cancer survivors-including those with multiple myeloma, lung cancer, and breast cancer-have an increased risk of developing cardiovascular disease (CVD) later in life compared to noncancer controls, while others such as prostate cancer survivors have a reduced risk, according to a new study. Overall, the survival of cancer survivors who develop CVD is generally poor.

Previous work has found a substantially elevated risk of CVD among survivors of childhood cancers, primarily due to exposure to cardiotoxic therapies such as anthracyclines and chest radiation. “Less is known regarding the magnitude of CVD risk in individuals diagnosed with cancer at an older age (≥ 40 years), a population that accounts for 95% of new cancer diagnoses in the United States,” wrote study authors led by Saro H. Armenian, DO, MPH, of City of Hope Comprehensive Cancer Center in Duarte, California.

The researchers conducted a retrospective cohort study of 36,232 survivors of adult-onset cancer who were at least 2 years from diagnosis. This was compared to a matched control cohort of 73,545 noncancer individuals. The results were published online ahead of print in the Journal of Clinical Oncology.

Compared with the controls, cancer survivors in general were more likely to have several CVD risk factors. These included hypertension (65.9% vs 59.5%; P < .01), diabetes (23.4% vs 21.5%; P < .01), dyslipidemia (57.9% vs 55.9%; P < .01), overweight/obesity (43.4% vs 35.4%; P < .01), and a history of smoking (32.7% vs 21.1%; P < .01).

A multiple regression model was used to determine the risk of CVD based on types of cancer. The greatest increased risk was seen in survivors of multiple myeloma, with an incident rate ratio (IRR) of 1.70 (95% CI, 1.31–2.21; P < .01). There was also a significant increase in those with carcinoma of the lung/bronchus, with an IRR of 1.58 (95% CI, 1.30–1.90; P < .01); non-Hodgkin lymphoma, with an IRR of 1.41 (95% CI, 1.20–1.65; P < .01); and breast cancer, with an IRR of 1.13 (95% CI, 1.06–1.22; P < .01). There was suggestion of increase in survivors of kidney and ovarian cancer as well, though these did not reach significance.

Prostate cancer survivors, in contrast, had a lower risk of developing CVD than controls, with an IRR of 0.89 (95% CI, 0.84–0.95; P < .01). Other malignancies including bladder cancer, colon cancer, melanoma, and others were not found to be at an increased risk of CVD.

The 5-year and 8-year overall survival rates were significantly worse among cancer survivors who developed CVD than among cancer survivors without CVD, which was similar to noncancer controls. Though the vast bulk of subsequent deaths among cancer survivors were due to cancer (70.5%), CVD was the second most common cause (8.8%).

“Outcomes after onset of CVD in long-term cancer survivors seem to be especially poor, emphasizing the need for additional studies to characterize the treatment-specific associations with long-term CVD risk as well as the effect of therapeutic strategies to mitigate this risk,” the authors concluded.