Cardiovascular disease prevention strategies are needed for adult cancer survivors, according to the researchers of a new widescale study that found some cancer patients are at higher cardiovascular risk. The researchers found that breast, lung, colorectal and hematologic/lymphatic cancers all had significant association with cardiovascular risk, but prostate cancer did not. The findings, from 12,414 participants in the prospective ARIC (Atherosclerosis Risk In Communities) study, were published Monday online, ahead of the July 5 issue of the Journal of the American College of Cardiology. Roberta Florido, MD, MHS, from Johns Hopkins University School of Medicine, and fellow authors noted that more than 80% of adult patients diagnosed with cancer survive in the long term but that the long-term complications of the disease and its treatments could raise the risk of cardiovascular disease. Despite the prevalence of cardiovascular disease among some cancer survivors – also shown in recent retrospective observational studies – however, the authors highlighted a lack of prospective studies using adjudicated cancer and cardiovascular disease events. “Understanding the true excess burden of [cardiovascular disease] and its subtypes in cancer survivors, as well as the degree to which [cardiovascular disease] risk in this population is explained by shared risk factors, can inform clinical and public health strategies for [cardiovascular disease] prevention in this unique patient population,” the researchers said. The ARIC cohort was initiated to study the risk factors and natural history of cardiovascular disease, with 15,792 participants aged between 45 and 64 years enrolled between 1987 and 1989 and followed prospectively every 3 years, with visits 5 to 8 occurring in 2011-2013, 2016-2017, 2018-2019 and 2020. The 12,414 participants included in the current study were narrowed down from the 15,641 who consented to cancer research, with those with prevalent cancer at baseline, prevalent cardiovascular disease at baseline and those with missing information excluded. Cancer diagnoses were ascertained via linkage with state registries and supplemented with medical records. At baseline, 9,171 patients had developed no cancer, while 3,250 (25%) had been diagnosed with a first primary cancer after visit 1, with a median time to cancer diagnosis of 13.6 years. Mean age was 53.6 years in the no-cancer cohort vs. 54.5 years in the cancer cohort, more men developed cancer (52.9% vs. 41.7%), and 31.4% of those in the no-cancer cohort had hypertension vs. 30.1% in the cancer cohort. Age-adjusted incidence rates of cardiovascular disease per 1,000 person-years – defined as coronary heart disease, heart failure, stroke and a composite of these outcomes – were 23.1 for cancer survivors (95% confidence interval [CI]: 24.7-29.1), and 12 for subjects without cancer (95% CI: 11.5 – 12.4). The median follow-up times to cardiovascular disease were 14 years (from visit 1 date) among those who never developed cancer and 5.2 years (from date of cancer diagnosis) among those who developed cancer. After adjusting for cardiovascular risk factors, the researchers found that cancer survivors had significantly higher risks of cardiovascular disease (HR: 1.37; 95% CI: 1.26-1.50), heart failure (HR: 1.52; 95% CI: 1.38-1.68) and stroke (HR: 1.22; 95% CI: 1.03-1.44). However, the risk was not significantly raised for coronary heart disease (HR: 1.11; 95% CI: 0.97-1.28). There were also no significant differences in the association of cancer and incident cardiovascular disease by race (P for interaction = 0.76). Cardiovascular risk association by cancer type The researchers also assessed cardiovascular disease risk by cancer type and found that breast (HR: 1.32; 95% CI: 1.08-1.60), lung (HR: 2.37; 95% CI: 1.84-3.06), colorectal (HR: 1.46; 95% CI: 1.15-1.85) and hematologic/lymphatic cancers (HR: 2.70; 95% CI: 2.04-3.59) were significantly associated with cardiovascular disease risk, whereas prostate cancer was not (HR: 1.10; 95% CI: 0.92-1.32). Postmenopausal breast cancer was the most common type among women (35%), and prostate cancer was the most common among men (40%). Lung (12%), colorectal (10.2%), and hematopoietic and lymphatic (8%) were the most common primary non–sex-related cancers. There was a stronger association of survivorship from non–sex-related cancers (excluding breast, cervical, endometrial, ovarian and prostate cancers) with incident cardiovascular disease among women vs men (women; HR: 1.96; 95% CI: 1.66-2.31 vs. men; HR: 1.57; 95% CI: 1.35-1.83, P for interaction <0.01). Median times from cancer diagnosis to any cardiovascular disease event were 6.2 years for breast, 6.3 years for prostate, 1.3 years for lung, 5.1 years for colorectal, and 3.1 years for hematopoietic and lymphatic cancers Age-adjusted incidence rates of cardiovascular disease per 1,000 person-years for survivors of specific cancers were 16.6 for breast (95% CI: 13.7-20.0), 21.0 for prostate (95% CI: 18.0-24.6), 50.0 for lung (95% CI: 39.0-64.2), 25.4 for colorectal (95% CI: 20.1- 32.0), and 41.0 for survivors of hematopoietic and lymphatic cancers (95% CI: 32.1-52.4). Unmet need for cardiovascular cancer strategies The researchers noted that, altogether, the results show that adult cancer survivors have a significantly higher risk of cardiovascular disease – especially heart failure – and that this is independent of traditional cardiovascular risk factors. “There is an unmet need to define strategies for [cardiovascular disease] prevention in this high-risk population,” they concluded. “Elucidating the mechanisms underlying the excess risk of [cardiovascular disease] among adult cancer survivors, from treatment toxicities to shared biological pathways, is needed in order to define novel strategies for predicting and preventing [cardiovascular disease] in this population.” In an accompanying editorial, Anthony F. Yu, MD, MS, and Richard M. Steingart, MD, from the Memorial Sloan Kettering Cancer Center and Weill Cornell Medical College, New York, stressed that these conclusions should be viewed as “preliminary” given study limitations – including that ARIC was not designed as a cancer survivorship study – adding that prospective risk factor intervention trials in cancer survivors “should be encouraged.” “Future studies are needed to identify alternative explanatory factors or other shared disease mechanisms that are responsible for the excess [cardiovascular disease] risk among cancer survivors so that effective preventive strategies to improve long-term [cardiovascular] health can be developed,” the editorialists concluded. Sources: Florido R, Daya NR, Ndumele CE, et al. Cardiovascular Disease Risk Among Cancer Survivors: The Atherosclerosis Risk In Communities (ARIC) Study. J Am Coll Cardiol 2022;80:22-32. Yu AF, Steingart RM. ARIC Welcomes Cancer Survivors Into Their Communities: Unraveling the Link Between Cancer and Cardiovascular Disease. J Am Coll Cardiol 2022;80:33-35. Image Credit: Rido – stock.adobe.com