Cardiac toxicity assessment in locally advanced breast cancer treated neoadjuvantly with doxorubicin/paclitaxel regimen

Should Patients Undergoing Chemotherapy and Radiotherapy Be Prescribed Antioxidants?

In September 2005, CA: A Cancer Journal for Clinicians published a warning by Gabriella D’Andrea, MD, against the concurrent use of antioxidants with radiotherapy and chemotherapy. However, several deficiencies of the CA article soon became apparent, not least the selective omission of prominent studies that contradicted the author’s conclusions. While acknowledging that only large-scale, randomized trials could provide a valid basis for therapeutic recommendations, the author sometimes relied on laboratory rather than clinical data to support her claim that harm resulted from the concurrent use of antioxidants and chemotherapy. She also sometimes extrapolated from chemoprevention studies rather than those on the concurrent use of antioxidants per se. The article overstated the degree to which the laboratory data diverged in regard to the safety and efficacy of antioxidant therapy: in fact, the preponderance of data suggests a synergistic or at least harmless effect with most high-dose dietary antioxidants and chemotherapy. The practical recommendations made in the article to avoid the general class of antioxidants during chemotherapy are inconsistent, in that if antioxidants were truly a threat to the efficacy of standard therapy, antioxidant-rich foods, especially fruits and vegetables, ought also be proscribed during treatment. Yet no such recommendation is made. Furthermore, the wide-scale use by both medical and radiation oncologists of synthetic antioxidants (eg, amifostine) to control the adverse effects of cytotoxic treatments is similarly overlooked. In sum, this CA article is incomplete: there is far more information available regarding antioxidant supplements as an appropriate adjunctive cancer therapy than is acknowledged. Patients would be well advised to seek the opinion of physicians who are adequately trained and experienced in the intersection of 2 complex fields, that is, chemotherapeutics and nutritional oncology. Physicians whose goal is comprehensive cancer therapy should refer their patients to qualified integrative practitioners who have such training and expertise to guide patients. A blanket rejection of the concurrent use of antioxidants with chemotherapy is not justified by the preponderance of evidence at this time and serves neither the scientific community nor cancer patients.

Long-term follow-up for cardiovascular disease after chemotherapy and/or radiotherapy for breast cancer in an unselected population

PURPOSE

Whereas earlier research focused on specific patient groups, this study assessed the risk of cardiovascular disease (CVD) in an unselected population curatively treated for breast cancer (BC), compared with an age-matched random sample of controls.

METHODS

Risks were determined in BC survivors and controls. CVD was divided into three categories: congestive heart failure, vascular cardiac diseases, and "other" cardiac diseases. Hazard ratios (HRs) and 95% confidence intervals (95% CI) adjusted for age, CVD, and CVD risk factors at baseline were determined by Cox regression analyses.

RESULTS

All 561 survivors of BC experienced surgery of whom 229 received (neo)adjuvant radiotherapy, 145 received chemotherapy (with or without radiotherapy), and 187 received no adjuvant therapy. During follow-up (median 9; range 5-57 years), CVD occurred in 176/561 (31%) survivors and in 398/1,635 (24%) controls. After radiotherapy, no increased risks of congestive heart failure (HR 0.5; 95% CI 0.2-1.8), vascular cardiac diseases (HR 1.1; 95% CI 0.7-1.7), or other cardiac diseases (HR 1.3; 95% CI 0.8-2.3) were found compared with controls. Similar results were found after chemotherapy for congestive heart failure (HR 1.8; 95% CI 0.6-5.8), vascular cardiac diseases (HR 1.1; 95% CI 0.5-2.3), and other cardiac diseases (HR 1.2; 95% CI 0.3-5.5).

CONCLUSIONS

In an unselected population of BC survivors, no significant increased risk of CVD after radiotherapy and/or chemotherapy was found compared with controls. However, the HRs after chemotherapy were in-line with previous studies. Future studies should include more detailed information on treatment and more specific outcome measures.

Targeted anti-mitotic therapies: can we improve on tubulin agents?

The advent of molecularly targeted drug discovery has facilitated the identification of a new generation of anti-mitotic therapies that target proteins with specific functions in mitosis. The exquisite selectivity for mitosis and the distinct ways in which these new agents interfere with mitosis provides the potential to not only overcome certain limitations of current tubulin-targeted anti-mitotic drugs, but to expand the scope of clinical efficacy that those drugs have established. The development of these new anti-mitotic drugs as targeted therapies faces significant challenges; nevertheless, these potential therapies also serve as unique tools to dissect the molecular mechanisms of the mitotic-checkpoint response.

Long-term assessment of cardiac function after dose-dense and -intense sequential doxorubicin (A), paclitaxel (T), and cyclophosphamide (C) as adjuvant therapy for high risk breast cancer

OBJECTIVES

This study evaluated the incidence of late cardiotoxicity after dose-dense and -intense adjuvant sequential doxorubicin (A), paclitaxel (T), and cyclophosphamide (C) for breast cancer (BC) with > or = 4 involved ipsilateral axillary lymph nodes.

METHODS

Patients were enrolled from 1994 to 2001 after definitive BC surgery if > or =4 axillary nodes were involved. Planned treatment was A 90 mg/m(2) q 14 days x 3, T 250 mg/m(2) q 14 days x 3, C 3 g/m(2 )q 14 days x 3 with filgrastim (G) support. Left ventricular ejection fraction (LVEF) was monitored using equilibrium radionuclide angiography (ERNA) before the initiation of chemotherapy, and after three cycles of each chemotherapeutic agent. At a median follow-up of 7 years, we obtained ERNA scans on 32 patients to evaluate the long-term cardiotoxicity of this regimen.

RESULTS

Eighty-five eligible patients enrolled on the treatment protocol. Clinical heart failure developed in one patient. Seven (8%) patients had LVEF < 50% at the end of therapy. No cardiac-related deaths occurred. Thirty-two (46%) of 69 surviving patients have consented to late cardiac imaging. At a median follow-up of 7 years, the median absolute change in LVEF from baseline was -5.5%; [range (-8%) to (+36%)], and from the end of chemotherapy was -2.0%; [range (-25%) to (+16%)]. Four patients (12%) had a LVEF < 50%; two of these four patients had an LVEF of < 50% at the end of chemotherapy.

CONCLUSIONS

Late development of asymptomatic decline in cardiac function may occur after dose-dense and -intense adjuvant therapy, but is uncommon.