A new UK Biobank study suggests that cancer survivors may have an increased long-term risk of subsequent cardiovascular disease, irrespective of traditional underlying risk factors.
Researchers, led by Queen Mary University of London, found that the highest rates of new cardiovascular disease occurred in cancer patients who had recovered from lung, blood or prostate cancer.
It is thought that the cancer treatments and the biological processes related to the cancer could be associated with the increased, long-term risk.
Previous studies suggest that the highest risk of cardiovascular complications arises in the first year after a cancer diagnosis, but the new findings published in the journal Heart are among the first to look at longer-term risks of cardiovascular disease in cancer survivors.
The researchers analysed the cardiovascular health of 18,714 UK Biobank participants for 12 years. The participants had a previous diagnosis of lung, breast, prostate, blood, womb, or bowel cancer and were compared with an equal number of participants with no history of cancer.
Nearly a third of the cancer survivors went on to develop cardiovascular disease, including ischaemic heart disease, stroke, atrial fibrillation, heart failure, impaired electrical signalling or mechanical heart problems, blood clots in the veins, arteries, or lungs, or pericarditis. New cases of ischaemic heart disease, atrial fibrillation, and heart failure were the most common types of cardiovascular disease across all cancers.
The researchers found that the risk of developing cardiovascular disease was higher in particular cancers. Patients who had survived lung cancer faced a 49.5% risk of heart problems, blood cancer patients a 48.5% risk and prostate cancer a 41% risk.
Participants who had not had a cancer diagnosis were found to have lower rates of new cardiovascular disease, with a 25% risk of developing the same heart conditions as the cancer survivors.
During the study period, 19% of cancer survivors died compared with 8.5% of those in the comparison group. Cardiovascular disease was found to be the primary cause of death in 1 in 12 of the cancer survivors who died.
The researchers also examined cardiovascular MRI imaging for 1,354 of the participants in order to pinpoint cardiac damage that had not yet resulted in symptoms. The findings revealed that the size and function of the heart among breast and blood cancer survivors had substantially changed for the worse, with functional heart changes seen in the breast cancer survivors.
Although the researchers state that their study cannot establish a definitive cause of the increased cardiac risk observed, in a linked BMJ editorial, Professor Jose Banchs and Dr Tara Lech of the University of Colorado School of Medicine who were involved in the study, highlighted the importance of post-cancer care in light of these findings.
They stated: ‘The importance of heart disease in patients undergoing cancer care cannot be understated, but also how critical it becomes to prioritise a care continuum after cancer is survived. The fantastic progress in the treatment and even cure of malignancies has undoubtedly highlighted the need for post-cancer care like never before.’