From cancer patients to cancer survivors: the issue of Cardioncology--a biological perspective

Predicting the risk of cardiovascular comorbidities in adult cancer survivors

OBJECTIVES

Data on how to identify cancer survivors (css) at the greatest risk for cardiovascular conditions are limited. We aimed to characterize the clinical factors associated with ischemic heart disease (ihd) and congestive heart failure (chf) in css and to develop a stratification schema for predicting the risk of cardiovascular comorbidities in css.

METHODS

Cancer survivors and non-cancer controls (nccs) were identified from the U.S. National Health and Nutrition Examination Survey. Independent factors associated with increased relative risk (rr) for cardiovascular conditions were determined. A risk stratification schema was devised that correlated risk score with the prevalence of cardiovascular comorbidities in cs.

RESULTS

Baseline characteristics were similar for the 1869 css and 24,337 nccs included in the study. Compared with nccs, css were more likely to report ihd (13.7% vs. 5.2%), chf (7.9% vs. 2.1%), or both (4.2% vs. 1.2%; all p < 0.01). Based on multivariate analyses, risk factors for cardiovascular problems included ages 40-60 years (rr: 3.66; 95% ci: 1.87 to 7.17), 60-80 years (rr: 14.18; 95% ci: 7.65 to 26.30), and 80 years or older (rr: 25.34; 95% ci: 13.16 to 48.78); male sex (rr: 2.25; 95% ci: 1.72 to 2.94); U.S. citizenship (rr: 2.10; 95% ci: 1.08 to 4.08); annual incomes of $20,000-$45,000 (rr: 1.81; 95% ci: 1.21 to 2.70) and less than $20,000 (rr: 3.05; 95% ci: 1.81 to 5.14); comorbid diabetes mellitus (rr: 2.97; 95% ci: 2.05 to 4.32); and physical inactivity (rr: 1.98; 95% ci: 1.41 to 2.79).

CONCLUSIONS

Independent risk factors for ihd and chf in css were identified. The risk stratification schema presented here may be helpful in developing a risk-based approach to preventive cardiovascular strategies for css.

Strategies to prevent and treat cardiovascular risk in cancer patients

Cardiotoxicity due to cancer treatment is of rising concern, for both cardiologists and oncologists, because it may have a significant impact on cancer patient management and outcome. The most typical manifestation of cardiotoxicity is a hypokinetic cardiomyopathy leading to heart failure. However, the spectrum of the toxic effects that can impair the cardiovascular system may also include acute coronary syndromes, hypertension, arrhythmias, and thromboembolic events. Patients undergoing cancer treatment are more vulnerable to cardiovascular injuries, and their risk of premature cardiovascular disease and death is higher than that of the general population. Prevention of cardiotoxicity remains the most important strategy, and several measures, including cardiac function monitoring, limitation of chemotherapy dose, use of anthracycline analogues and cardioprotectants, and early detection of myocardial cell injury by biomarkers, have been proposed. The response to modern heart failure therapy of cancer treatment-induced cardiomyopathy has never been evaluated in clinical trials, and currently there are no definitive guidelines. Although it is likely that medications used for other forms of cardiomyopathy, particularly angiotensin-converting enzyme inhibitors and β-blockers, may be highly effective, there is still some unjustified concern regarding their use in cancer patients. Specific guidelines that take cardiologic conditions of cancer patients into account are currently lacking and need to be developed.

Differences in routine laboratory parameters related to cachexia between patients with hematological diseases and patients with solid tumors or heart failure - is there only one cachexia?

Background

Cachexia is a state of involuntary weight loss common to many chronic diseases. Experimental data, showing that cachexia is related to the enhancement of acute phase response reaction, led to the new definition of cachexia that included, aside from the principal criterion of weight loss, other “minor criteria”, Amongst them are levels of C-reactive protein (CRP), albumin and hemoglobin. However, there is paucity of data regarding possible differences of these laboratory parameters in patients with various diseases known to be related to cachexia.

Methods

CRP, albumin and hemoglobin were evaluated in 119 patients, divided into two disease groups, hematological (ones with diagnosis of non-Hodgkin lymphoma or Hodgkin disease) and non-hematological (solid tumor patients and patients with chronic heart failure). Patients were further subdivided into two nutritional groups, cachectic and non-cachectic ones according to the principal criterion for cacxehia i.e. loss of body weight.

Results

We found that cachectic patients had higher levels of CRP, and lower levels of both hemoglobin and albumin compared to non-cachectic patients, regardless of the disease group they fitted. On the other hand, the group of hematological patients had lower levels of CRP primarily due to the differences found in the non-cachectic group. Higher levels of albumin were also found in the hematological group regardless of the nutritional group they fitted. Limitations of cut-off values, proposed by definition, were found, mostly regarding their relatively low sensitivity and low negative predictive value.

Conclusions

As expected, differences in values of routine laboratory parameters used in definition of cachexia were found between cachectic and non-cachectic patients. Their values differed between hematological and non-hematological patients both in cachectic and non-cachectic group. Cut-off levels currently used in definition of cachexia have limitations and should be further evaluated.

Capecitabine in breast cancer: the issue of cardiotoxicity during fluoropyrimidine treatment

Capecitabine is an orally available fluoropyrimidine carbamate that selectively delivers fluorouracil (5-FU) to tissues expressing high levels of thymidine phosphorylase (TP) such as tumors. The drug has demonstrated efficacy in metastatic breast cancer, colorectal, and pancreatic cancer. Although these are considered safe drugs, a growing body of literature reports adverse cardiac effects. Clinical trials indicate that capecitabine has a cardiac toxicity similar to that of infused fluoropyrimidines such as 5-FU. Here, we review cardiotoxicity in the use of fluoropyrimidines, with particular attention toward capecitabine. We also describe a severe, reversible cardiac event that occurred in a 39-year-old woman, with no cardiac risk factors, treated with capecitabine for advanced breast cancer. This review and our experience confirm that fluoropyrimidine cardiotoxicity is an infrequent but documented side effect. Oncology patients under treatment should be closely observed and monitored for cardiac symptoms with particular attention in case of signs or symptoms of cardiovascular complications. The implementation of cardio-oncology interdisciplinary teams should, in the future, reduce the impact of cancer treatment-associated cardiotoxicity syndromes.