A study led by Dr. Kathleen Sturgeon published in the European Heart Journal showed that in patients diagnosed with cancer, the majority of cardiovascular deaths in the United States occur in patients diagnosed with breast, prostate or bladder cancer. Additionally, the investigators demonstrated that patients with cancer are at a higher risk of dying from cardiovascular disease as compared to the general population.
Globally, heart disease and cancer are two of the leading causes of death with at least 1 million deaths attributed to these medical conditions in the United States in 2015 alone. With the increasing availability of more advanced forms of treatment for cancer, there has been a steady increase in cancer survival rates. There is a need to better improve cardiovascular care in this growing population. Due to the increasing complexity of care for patients with cancer, there is a need to better understand the burden of cardiovascular disease in these patients. The investigators aimed to describe mortality due to cardiovascular disease in cancer patients.
Using data from the Surveillance, Epidemiology and End Results (SEER) program, the investigators identified patients with invasive cancer, diagnosed between 1973 and 2015. For all patients who died, the cause of death was identified. Standardized mortality ratios (SMR) were calculated. SMR provides the relative risk of death from cardiovascular disease in cancer survivors as compared to all residents in the United States and adjusts for age, race, and sex. Of the 3,234,256 cancer survivors included in the study, 1,228,328 patients died from cancer (38.0%) and 365,689 patients died from cardiovascular disease (11.3%).
The investigators found that patients with urinary bladder cancer had the highest risk of dying from cardiovascular disease (19.4%). This was followed by laryngeal cancer (17.3%), prostate cancer (16.6%), corpus uteri (15.6%), colorectal cancer (13.7%) and breast cancer (11.7%). Additionally, patients with either prostate or breast cancer had the highest number of absolute deaths from cardiovascular disease and make up the largest percentage of patients who died from CVD. Also, patients diagnosed with cancer at the age of 85 or more have an increased risk of death from heart disease compared to men and women in the general population. The younger the patient is at the age of diagnosis, the higher the risk of death from CVD. In patients diagnosed with cancer before 55 years of age, the risk of CV mortality is more than ten times greater than the general population. Risk of death from CV disease decreases as age at cancer diagnosis increases: (55–64 years of age: SMR 7.5; 65–74 years of age: SMR 3.8; 75–84 years of age: SMR 2.4). Finally, the investigators found that cardiovascular disease mortality is highest within the first year after cancer diagnosis and remains elevated throughout the follow-up period.
The investigators demonstrated that patients with cancer have a higher risk of dying from cardiovascular disease as compared to the general population. Additionally, the investigators found that in cancers with a greater than 20% risk of death from CVD, the risk of dying from the index cancer is less than 30%. The investigators hypothesize that this relationship may be attributed to a better prognosis in those specific cancers. The results of this study highlight the need to better optimize cardiovascular care in patients with cancer. Dr. Sturgeon wrote, “Our observations highlight the need for earlier and more aggressive cardiovascular care in cancer patients which may require enhanced coordinated care between oncologists, cardiologists, and PCPs”.