Anthracycline-induced cardiotoxicity in patients with early-stage breast cancer: the Canadian Cancer Trials Group (CCTG) MA.21 experience.

PURPOSE: Anthracyclines are frequently used in adjuvant treatment for early-stage breast cancer (ESBC). The purpose of this study was to evaluate cardiotoxic effects in the first five years after treatment with different anthracycline-based regimens. METHODS: CCTG MA.21 (NCT000142) was a phase III trial in ESBC that compared cyclophosphamide (75 mg/m2) orally for 14 days, epirubicin (60 mg/m2) and fluorouracil, IV days one and eight (CEF) for six cycles; dose-dense epirubicin (120 mg/m2) and cyclophosphamide, IV every 2 weeks for six cycles with concurrent G-CSF then paclitaxel every 2 weeks for four cycles (ddEC/T); doxorubicin (60 mg/m2) and cyclophosphamide (600 mg/m2) every 3 weeks for four cycles then four cycles q3 weekly paclitaxel (175 mg/m2) (AC/T). ENDPOINTS: LVEF decline; LV function changes (heart failure), or Grade 3-4 cardiac ischemia/infarction. A competing risk analysis was performed with endpoints of cardiotoxicity or recurrence in first 5 years after completion of chemotherapy. RESULTS: 2104 women were randomized. Compliance with cardiac LVEF assessments was 70% at 5 years in all arms. The 5-year cumulative risks of any cardiac event for CEF, ddECT, and AC/T were 22.3% (95%CI 18.9 to 25.7), 14.2% (95%CI 11.0 to 17.3), and 8.1% (95%CI 5.8 to 10.4), respectively, p < 0.0001. At 5 years, women in the ddEC/T and AC/T group had significantly lower risk of cardiotoxicity than those given CEF (HR 0.599 and 0.371, respectively). Most events were asymptomatic drop in LVEF. CONCLUSIONS: Asymptomatic changes in LVEF accounted for most of the cardiotoxicity. The majority of cardiac events occurred in year one although occurrence of cardiotoxicity over time highlights the need for improved risk stratification to guide cardiac surveillance strategies.

A multicentre, randomised trial comparing schedules of G-CSF (filgrastim) administration for primary prophylaxis of chemotherapy-induced febrile neutropenia in early stage breast cancer.

BACKGROUND: The optimal duration of filgrastim as primary febrile neutropenia (FN) prophylaxis in early breast cancer patients is unknown, with 5, 7 or 10 days being commonly prescribed. This trial evaluates whether 5 days of filgrastim was non-inferior to 7/10 days. PATIENTS AND METHODS: In this randomised, open-label trial, early breast cancer patients who were to receive filgrastim as primary FN prophylaxis were randomly allocated to 5 versus 7 versus 10 days of filgrastim for all chemotherapy cycles. A protocol amendment in November 2017 allowed subsequent patients (N = 324) to be randomised to either 5 or 7/10 days. The primary outcome was a composite of either FN or treatment-related hospitalisations. Secondary outcomes included chemotherapy dose reductions, delays and discontinuations. Analyses were carried out by per protocol (primary) and intention-to-treat, and the non-inferiority margin was set at 3% for the risk of having FN and/or hospitalisation per cycle of chemotherapy. RESULTS: Patients (N = 466) were randomised to receive 5 (184, 39.5%), or 7/10 (282, 60.5%) days of filgrastim. In our primary analysis, the difference in risk of either FN or treatment-related hospitalisation per cycle was -1.52% [95% confidence interval (CI): -3.22% to 0.19%] suggesting non-inferiority of a 5-day filgrastim schedule compared with 7/10-days. The difference in events per cycle for FN was 0.11% (95% CI: -1.05 to 1.27) while for treatment-related hospitalisations it was -1.68% (95% CI: -2.73% to -0.63%). The overall proportions of patients having at least one occurrence of either FN or treatment-related hospitalisation were 11.8% and 14.96% for the 5- and 7/10-day groups, respectively (risk difference: -3.17%, 95% CI: -9.51% to 3.18%). CONCLUSION: Five days of filgrastim was non-inferior to 7/10 days. Given the cost and toxicity of this agent, 5 days should be considered standard of care. CLINICALTRIALS. GOV REGISTRATION: NCT02428114 and NCT02816164.

Effect of obesity, dyslipidemia, and diabetes on trastuzumab-related cardiotoxicity in breast cancer.

Background: Clinical trials have demonstrated an increased risk of cardiotoxicity in patients with breast cancer (bca) receiving trastuzumab-based therapy. Diabetes, dyslipidemia, and obesity are known risk factors for cardiovascular disease. Studies have yielded conflicting results about whether those factors increase the risk of cardiotoxicity in patients with bca receiving trastuzumab. Methods: In this retrospective cohort study, data were collected for 243 patients with bca positive for her2 (the human epidermal growth factor receptor 2) who were receiving trastuzumab and who were referred to The Ottawa Hospital Cardio-oncology Referral Clinic between 2008 and 2013. The data collected included patient demographics, reason for referral, cardiac function, chemotherapy regimen (including anthracycline use), and 3 comorbidities (diabetes, dyslipidemia, obesity). Rates of symptomatic cancer treatment-related cardiac dysfunction (sctcd) and asymptomatic decline in left ventricular ejection fraction (adlvef) were calculated for patients with and without the comorbidities of interest. Results: Of the 243 identified patients, 104 had either diabetes, dyslipidemia, or obesity. In that population, the most likely reason for referral to the cardio-oncology clinic was adlvef. The combination of 2 or 3 comorbidities significantly increased the incidence of sctcd in our population, reaching a rate of 67% for patients with obesity and dyslipidemia [relative risk (rr): 2.2; p = 0.04], 69% for patients with obesity and diabetes (rr: 2.3; p = 0.02), and 72% for patients with all 3 risk factors (rr: 2.4; p = 0.08). Conclusions: The combination of 2 or 3 comorbidities significantly increases the incidence of symptomatic cancer treatment-related cardiotoxicity. Patients with bca experiencing cancer treatment-related cardiotoxicity who have a history of diabetes, dyslipidemia, and obesity might require more proactive strategies for prevention, detection, and treatment of cardiotoxicity while receiving trastuzumab-based treatment.

Clinical experience of patients referred to a multidisciplinary cardio-oncology clinic: an observational cohort study.

Introduction: Cardiovascular disease is the 2nd leading cause of long-term morbidity and mortality in cancer survivors. Cardio-oncology clinics (cocs) have emerged to address the issue; however, there is a paucity of data about the demographics and clinical outcomes of patients seen in the coc setting. Methods: Cancer patients referred to The Ottawa Hospital coc were included in this retrospective observational study. Data collected were patient demographics, cancer type and stage, reason for referral, cardiac risk factors, cardiac assessments and treatment, and clinical outcomes. Results: Between 2008 and 2015, 779 patients (516 women, 66%; 263 men, 34%) were referred to the coc. Median age of the patients at cancer diagnosis was 60 years (range: 18-90 years). The most frequent reasons for referral were decreased left ventricular ejection fraction (33%), pre-chemotherapy assessment (14%), and arrhythmia (14%). Treatment with cardiac medication was given in 322 patients (41%), 181 (56%) of whom received more than 2 cardiac medications, with 57 (18%) receiving an angiotensin-converting enzyme inhibitor (acei), 46 (14%) receiving an acei and a beta-blocker, and 38 (12%) receiving a beta-blocker. Of 163 breast cancer patients, 129 (79%) were able to complete targeted therapy with coc co-management. Most of the 779 patients (n = 643, 83%) were alive at the time of the last data collection. Conclusions: This cohort study is one of the largest to report characteristics and clinical outcomes of patients referred to a coc. Collaboration between oncologists and cardiologists resulted in completion of cancer therapy in most patients. Ongoing analysis of referral patterns, management plans, and patient outcomes will help to guide the cardiac care of oncology patients, ultimately optimizing cancer and cardiac outcomes alike.