Incidence of Cardiovascular Disease May Increase in Older Adults With Cancer

A new study reveals that older adults with cancer, particularly those with metastatic or hematological cancers, may demonstrate an elevated risk of cardiovascular disease.

Among older adults with cancer, incidence of cardiovascular disease (CVD), including myocardial infarction (MI), hospitalization for heart failure (HHF) and ischemic stroke, was increased; however, aspirin did not impact CVD incidence, and risk may be higher in those with metastatic, hematological and lung cancer and following chemotherapy, according to study findings published in Cancer.

“There are a number of chemotherapy drugs that are known to cause stress and damage the heart, and these are called cardiotoxic drugs. Both chemotherapy and radiotherapy can lead to increased levels of inflammation, which leads to damage to the heart and vessels. Additionally, radiotherapy near the heart [thoracic] can cause direct damage through hardening of vessels and over time, tissue becomes fibrous and tough,” Suzanne Orchard said in an email interview with CURE®.

Orchard, a senior research fellow in the School of Public Health and Preventive Medicine and the Director of the ASPREE Extension at Monash University in Melbourne, Australia, was among the researchers on the ASPREE trial and a co-author of the study published in Cancer.

The ASPREE trial consisted of 15,454 Australian (87% of patients) and American participants aged 70 years or older (65 years or older for United States ethnic minorities), of which 1,392 had an incident cancer diagnosis (new diagnosis of cancer). Patients were further grouped into the cancer risk-set (at risk for developing cancer) and the cancer-free risk-set group (not considered at risk for developing cancer), which demonstrated 20.8 cardiovascular events per 1000 years of patients’ combined life lived (person-years) and 10.3 events per 1000 person-years, respectively.

Of note, incidence was highest in metastatic (spreading), hematological (blood and bone marrow) and lung cancer. Incidence rates remained the same after considering factors that are known to increase the risk of CVD, and similar rates of CVD were seen across both aspirin and placebo groups; however, chemotherapy was associated with increased risk of CVD. Patients with breast cancer, colorectal cancer, melanoma and prostate cancer did not show an increased risk of any cardiovascular outcome.

“The CVD risk in those taking aspirin was the same as that in those not taking aspirin, and so, we found no benefits [of aspirin] in terms of decreasing CVD risk post-cancer diagnosis,” said Orchard.

Patients participating in the study were to have no prior history of CVD events, dementia or significant physical disability and were expected to survive at least five years after study enrollment.

Regarding side effects, “we do know that low-dose aspirin increases the risk of bleeding, and this was one of the main outcomes from the ASPREE clinical trial [a double-blind, placebo-controlled randomized trial of low dose aspirin in older adults],” Orchard said. “And so, for anyone considering taking aspirin for purposes other than secondary CVD prevention [as prescribed by their doctor], a conversation with their primary care provider should occur first, as there are a number of things to consider before establishing if any benefits would outweigh any potential harms such as bleeding.”

The most common cancer types after patients had been assigned to different treatment groups were prostate (26%), colorectal (14%), breast (12%), hematological (11%), lung (8%) and melanoma (8%). Additionally, 78% of cancers were non‐metastatic and the most common metastatic solid tumors were lung (20%), prostate (18%), colorectal (15%), pancreatic (9%) and ovarian/endometrial (8%).

Out of all cancer types, “we found an elevated risk of blood and lung cancers. Both of these cancers are typically more advanced at the point of diagnosis, which would mean a higher tumor burden [therefore cancer-related inflammation], more aggressive treatment regimens and also prior deconditioning of the individual, all leading to increased CVD risk. Our data also suggested higher risks with prostate and colorectal cancer, but this data was not statistically significant,” Orchard said.

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