Chemotherapy can increase cardiovascular risks and cancer recurrence

Category: Cancer

 

In this article we will explain the connection between chemotherapy and increased recurrence risks in prostate cancer patients and increased cardiovascular problems in breast cancer patients who had no prior elevated risk factors for cardiovascular disease.

This is from PennMed’s oncolink website:

Some chemotherapy drugs can indeed cause increase in cholesterol levels, as can hormonal agents. Radiation to certain areas of the body (the liver, for example) could theoretically cause this as well, although this is much less common.

In addition to cancer treatments causing increased cholesterol, some cancer treatments may also increase other cardiovascular risk factors, such as atherosclerosis (plaque formation) and/or cardiomyopathy.1

Research from the University of Southern California examined the effect of chemotherapy on the development of metabolic syndrome in premenopausal and postmenopausal women with early-stage breast cancer who were receiving  neoadjuvant therapy before surgery for the treatment of breast cancer.

Neoadjuvant therapy is where a treatment is given as a first step to shrink a tumor before the main treatment, which is usually surgery, is given. Examples of neoadjuvant therapy include chemotherapy, radiation therapy, and hormone therapy. (Definition from NIH National Cancer Institute)

The women in the study were considered free of clinical determination of metabolic syndrome (components include overweight as being determined by  waist circumference; blood pressure; and fasting levels of blood glucose, triglycerides, and high-density lipoprotein cholesterol.

Anthropometrics (body weight, percentage body fat, fat mass), lipid profile (total cholesterol, low-density lipoprotein cholesterol), glucose metabolism (insulin, homeostatic model assessment of insulin resistance, glycated hemoglobin), and inflammation (C-reactive protein) also were examined before initiating and after completing treatment.

What the researchers found was that a  12-week to 18-week course of chemotherapy appears to statistically significantly increase metabolic syndrome and related anthropometrics, biomarkers of glucose metabolism, and inflammation in patients with early-stage breast cancer with no preexisting conditions.

Lifestyle interventions such as diet and exercise may be preventive approaches for use during chemotherapy to reduce the onset of metabolic syndrome in patients with breast cancer. 1

A similar connection has been made in men with prostate cancer

Higher levels of total cholesterol and triglycerides in the blood of men who underwent surgery for prostate cancer, were associated with increased risk for disease recurrence, according to a study published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.

“While laboratory studies support an important role for cholesterol in prostate cancer, population-based evidence linking cholesterol and prostate cancer is mixed,” said Emma Allott, PhD, postdoctoral associate at Duke University School of Medicine in Durham, North Carolina. “Understanding associations between obesity, cholesterol, and prostate cancer is important given that cholesterol levels are readily modifiable with diet and/or statin use, and could therefore have important, practical implications for prostate cancer prevention and treatment.

“Our findings suggest that normalization, or even partial normalization, of serum lipid levels among men with dyslipidemia [abnormal lipid profile] may reduce the risk of prostate cancer recurrence,” said Allott.

Allott, Stephen Freedland, MD, associate professor of surgery at Duke University School of Medicine, and colleagues, analyzed data from 843 men who underwent radical prostatectomy after a prostate cancer diagnosis and who never took statins before surgery. They found that those who had serum triglyceride levels of 150 mg/dL or higher had a 35 percent increased risk for prostate cancer recurrence, when compared with patients who had normal levels of triglycerides. Among those with abnormal blood lipid profile, for every 10 mg/dL increase in total serum cholesterol above 200 mg/dL, there was a 9 percent increased risk for prostate cancer recurrence.

For every 10 mg/dL increase in high density lipoprotein (HDL; known as “good” cholesterol) among men with abnormal HDL (below the desirable value of 40 mg/dL), the risk for prostate cancer recurrence was lowered by 39 percent.

“Given that 45 percent of deaths worldwide can be attributed to cardiovascular disease and cancer, with prostate cancer being the second most common cause of male cancer deaths in the United States, understanding the role of dyslipidemia as a shared, modifiable risk factor for both of these common causes of mortality is of great importance,” she added.

Study subjects were identified from the Shared Equal Access Regional Cancer Hospital (SEARCH) database and treated at one of the six Veterans Affairs Medical Centers in California, North Carolina, and Georgia.

Of the 843 men studied, 343 were black, 325 had abnormal cholesterol levels, 263 had abnormal triglyceride levels, and 293 had a biochemical recurrence, defined as rising PSA levels after prostate cancer treatment, indicating the recurrence of the patient’s prostate cancer.