Neurohormonal, hemodynamic, and electrocardiographic evaluations of healthy dogs receiving long-term administration of doxorubicin

Objective - To evaluate diagnostic testing that could be used to establish an early diagnosis of cardiotoxicosis induced by long-term administration of doxorubicin. Animals - 13 adult mixed-breed dogs. Procedures - 7 dogs were administered doxorubicin chloride (30 mg/m2, IV, q 21 d for 168 days [cumulative dose, 240 mg/m2]), and 6 dogs received saline (0.9% NaCl) solution (5 mL, IV, q 21 d for 168 days; control group). Echocardiography, ECG, arterial blood pressure, plasma renin activity (PRA), and plasma concentrations of norepinephrine and brain natriuretic peptide (BNP) were assessed before each subsequent administration of doxorubicin and saline solution. Results - Dogs that received doxorubicin had a significant decrease in R-wave amplitude, compared with values for the control group, from 30 to 210 mg/m2. Doxorubicin-treated dogs had decreases in fractional shortening and left ventricular ejection fraction evident as early as 30 mg/m2, but significant differences between groups were not detected until 90 mg/m2 was reached. There was also a significant increase in PRA (≥ 120 mg/m2) and left ventricular end-systolic and end-diastolic dimensions (≥ 60 and ≥ 180 mg/m2, respectively). Systemic arterial pressure, remaining echocardiographic variables, and concentrations of norepinephrine and BNP had significant variations, but of no clinical importance, during doxorubicin administration. Conclusions and clinical relevance - Doxorubicin-induced cardiotoxicosis developed at 120 mg/m2, but there were no clinical signs of dilated cardiomyopathy or congestive heart failure. Echocardiography and determination of PRA were able to detect early cardiac alterations during the development of dilated cardiomyopathy, despite apparently differing degrees of sensitivity to development of doxorubicin-induced cardiotoxicosis.

Paclitaxel versus doxorubicin as first-line single-agent chemotherapy for metastatic breast cancer: a European Organization for Research and Treatment of Cancer Randomized Study with cross-over.

PURPOSE: To compare the efficacy of paclitaxel versus doxorubicin given as single agents in first-line therapy of advanced breast cancer (primary end point, progression-free survival ¿PFS) and to explore the degree of cross-resistance between the two agents. PATIENTS AND METHODS: Three hundred thirty-one patients were randomized to receive either paclitaxel 200 mg/m(2), 3-hour infusion every 3 weeks, or doxorubicin 75 mg/m(2), intravenous bolus every 3 weeks. Seven courses were planned unless progression or unacceptable toxicity occurred before the seven courses were finished. Patients who progressed within the seven courses underwent early cross-over to the alternative drug, while a delayed cross-over was optional for the remainder of patients at the time of disease progression. RESULTS: Objective response in first-line therapy was significantly better (P =.003) for doxorubicin (response rate ¿RR, 41%) than for paclitaxel (RR, 25%), with doxorubicin achieving a longer median PFS (7.5 months for doxorubicin v 3.9 months for paclitaxel, P <.001). In second-line therapy, cross-over to doxorubicin (91 patients) and to paclitaxel (77 patients) gave response rates of 30% and 16%, respectively. The median survival durations of 18.3 months for doxorubicin and 15.6 months for paclitaxel were not significantly different (P =.38). The doxorubicin arm had greater toxicity, but this was counterbalanced by better symptom control. CONCLUSION: At the dosages and schedules used in the present study, doxorubicin achieves better disease and symptom control than paclitaxel in first-line treatment. Doxorubicin and paclitaxel are not totally cross-resistant, which supports further investigation of these drugs in combination or in sequence, both in advanced disease and in the adjuvant setting.

A joined analysis of two European Organization for the Research and Treatment of Cancer (EORTC) studies to evaluate the role of pegylated liposomal doxorubicin (Caelyx) in the treatment of elderly patients with metastatic breast cancer.

We have performed a retrospective analysis to evaluate the impact of age, using a 70 year cutoff, on the safety and efficacy of pegylated liposomal doxorubicin (Caelyx) given at 60 mg/m(2) every 6 weeks (treatment A) or 50 mg/m(2) every 4 weeks (treatment B) to 136 metastatic breast cancer patients in two EORTC trials, of whom 65 were 70 years of age or older. No difference in terms of toxicity was observed between younger and older patients treated with the 4-week schedule, while a higher incidence of hematological toxicity, anorexia, asthenia, and stomatitis was observed in older patients when the 6-week schedule was used. Antitumor activity was not affected by age. In the older cohort of patients, no dependence was found between the incidence of grade 3-4 toxicity or antitumor activity and patients' baseline performance status, number and severity of comorbidities, or number of concomitant medications. The higher therapeutic index of Caelyx 50 mg/m(2) every 4 weeks makes it, of the two dose schedules investigated, the preferred regimen in the elderly.

A randomised phase II study of two different schedules of pegylated liposomal doxorubicin in metastatic breast cancer (EORTC-10993).

One hundred and sixteen women with measurable metastatic breast cancer participated in a randomised phase II study of single agent liposomal pegylated doxorubicin (Caelyx) given either as a 60 mg/m2 every 6 weeks (ARM A) or 50 mg/m2 every 4 weeks (ARM B) schedule. Patients were over 65 years of age or, if younger, had refused or been unsuitable for standard anthracyclines. The aims of the study were to evaluate toxicity and dose delivery with the two schedules and obtain further information on the response rate of liposomal pegylated doxorubicin as a single agent in anthracycline nai ve advanced breast cancer. Twenty-six patients had received prior adjuvant chemotherapy (including an anthracycline in 10). Sixteen had received non-anthracycline-based first-line chemotherapy for advanced disease. One hundred and eleven patients were evaluable for toxicity and 106 for response. The delivered dose intensity (DI) was 9.8 mg/m2 (95% CI, 7.2-10.4) with 37 (69%) achieving a DI of >90% on ARM A and 11.9 mg/m2 (95% CI, 7.5-12.8) with 37 (65%) achieving a DI of >90% on ARM B. The adverse event profiles of the two schedules were distinctly different. Mucositis was more common with the every 6 weeks regimen (35% CTC grade 3/4 in ARM A, 14% in ARM B) but palmar plantar erythrodysesthesia (PPE) was more frequent with the every 4 weeks regimen (2% CTC grade 3/4 in ARM A, 16% in ARM B). Confirmed objective partial responses by RECIST criteria were seen with both schedules; 15/51 (29%) on ARM A and 17/56 (31%) on ARM B. Liposomal pegylated doxorubicin showed significant activity in advanced breast cancer with a generally favourable side-effect profile. The high frequency of stomatitis seen with 6 weekly treatment makes this the less preferred of the two schedules tested.

Randomized, controlled trial investigating short-term health-related quality of life with doxorubicin and paclitaxel versus doxorubicin and cyclophosphamide as first-line chemotherapy in patients with metastatic breast cancer: European Organization for Research and Treatment of Cancer Breast Cancer Group, Investigational Drug Branch for Breast Cancer and the New Drug Development Group Study.

PURPOSE: To compare health-related quality of life (HRQOL) in patients with metastatic breast cancer receiving the combination of doxorubicin and paclitaxel (AT) or doxorubicin and cyclophosphamide (AC) as first-line chemotherapy treatment. PATIENTS AND METHODS: Eligible patients (n = 275) with anthracycline-naive measurable metastatic breast cancer were randomly assigned to AT (doxorubicin 60 mg/m(2) as an intravenous bolus plus paclitaxel 175 mg/m(2) as a 3-hour infusion) or AC (doxorubicin 60 mg/m(2) plus cyclophosphamide 600 mg/m(2)) every 3 weeks for a maximum of six cycles. Dose escalation of paclitaxel (200 mg/m(2)) and cyclophosphamide (750 mg/m(2)) was planned at cycle 2 to reach equivalent myelosuppression in the two groups. HRQOL was assessed with the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire C30 and the EORTC Breast Module at baseline and the start of cycles 2, 4, and 6, and 3 months after the last cycle. RESULTS: Seventy-nine percent of the patients (n = 219) completed a baseline measure. However, there were no statistically significant differences in HRQOL between the two treatment groups. In both groups, selected aspects of HRQOL were impaired over time, with increased fatigue, although some clinically significant improvements in emotional functioning were seen, as well as a reduction in pain over time. Overall, global quality of life was maintained in both treatment groups. CONCLUSION: This information is important when advising women patients of the expected HRQOL consequences of treatment regimens and should help clinicians and their patients make informed treatment decisions.

Doxorubicin-paclitaxel: a safe regimen in terms of cardiac toxicity in metastatic breast carcinoma patients. Results from a European Organization for Research and Treatment of Cancer multicenter trial.

BACKGROUND: The potential cardiotoxicity of the doxorubicin-paclitaxel regimen, when paclitaxel is given shortly after the end of the anthracycline infusion, is an issue of concern, as suggested by small single institution Phase II studies. METHODS: In a large multicenter Phase III trial, 275 anthracycline naive metastatic breast carcinoma patients were randomized to receive either doxorubicin (60 mg/m(2)) followed 30 minutes later by paclitaxel (175 mg/m(2) 3-hour infusion; AT) or a standard doxorubicin-cyclophosphamide regimen (AC; 60/600 mg/m(2)). Both treatments were given once every 3 weeks for a maximum of six cycles. Close cardiac monitoring was implemented in the study design. RESULTS: Congestive heart failure (CHF) occurred in three patients in the AT arm and in one patient in the AC arm (P = 0.62). Decreases in left ventricular ejection fraction to below the limit of normal were documented in 33% AT and 19% AC patients and were not predictive of CHF development. CONCLUSIONS: AT is devoid of excessive cardiac risk among metastatic breast carcinoma patients, when the maximum planned cumulative dose of doxorubicin does not exceed 360 mg/m(2).

Doxorubicin and paclitaxel versus doxorubicin and cyclophosphamide as first-line chemotherapy in metastatic breast cancer: The European Organization for Research and Treatment of Cancer 10961 Multicenter Phase III Trial.

PURPOSE: To compare the efficacy and tolerability of the combination of doxorubicin and paclitaxel (AT) with a standard doxorubicin and cyclophosphamide (AC) regimen as first-line chemotherapy for metastatic breast cancer. PATIENTS AND METHODS: Eligible patients were anthracycline-naive and had bidimensionally measurable metastatic breast cancer. Two hundred seventy-five patients were randomly assigned to be treated with AT (doxorubicin 60 mg/m(2) as an intravenous bolus plus paclitaxel 175 mg/m(2) as a 3-hour infusion) or AC (doxorubicin 60 mg/m(2) plus cyclophosphamide 600 mg/m(2)) every 3 weeks for a maximum of six cycles. A paclitaxel (200 mg/m(2)) and cyclophosphamide (750 mg/m(2)) dose escalation was planned at cycle 2 if no grade >or= 3 neutropenia occurred in cycle 1. The primary efficacy end point was progression-free survival (PFS). Secondary end points were response rate (RR), safety, overall survival (OS), and quality of life. RESULTS: A median number of six cycles were delivered in the two treatment arms. The relative dose-intensity and delivered cumulative dose of doxorubicin were lower in the AT arm. Dose escalation was only possible in 17% and 20% of the AT and AC patients, respectively. Median PFS was 6 months in the two treatments arms. RR was 58% versus 54%, and median OS was 20.6 versus 20.5 months in the AT and AC arms, respectively. The AT regimen was characterized by a higher incidence of febrile neutropenia, 32% versus 9% in the AC arm. CONCLUSION: No differences in the efficacy study end points were observed between the two treatment arms. Treatment-related toxicity compromised doxorubicin-delivered dose-intensity in the paclitaxel-based regimen

Late morfofunctional alterations of the Sertoli cell caused by doxorubicin administered to prepubertal rats

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Acute doxorubicin-induced cardiotoxicity is associated with matrix metalloproteinase-2 alterations in rats

Background: Doxorubicin can cause cardiotoxicity. Matrix metalloproteinases (MMP) are responsible for degrading extracellular matrix components which play a role in ventricular dilation. Increased MMP activity occurs after chronic doxorubicin treatment. In this study we evaluated in vivo and in vitro cardiac function in rats with acute doxorubicin treatment, and examined myocardial MMP and inflammatory activation, and gene expression of proteins involved in myocyte calcium transients. Methods: Wistar rats were injected with doxorubicin (Doxo, 20 mg/kg) or saline (Control). Echocardiogram was performed 48 h after treatment. Myocardial function was assessed in vitro in Langendorff preparation. Results: In left ventricle, doxorubicin impaired fractional shortening (Control 0.59 +/- 0.07; Doxo 0.51 +/- 0.05; p &lt; 0.001), and increased isovolumetric relaxation time (Control 20.3 +/- 4.3; Doxo 24.7 +/- 4.2 ms; p = 0.007) and myocardial passive stiffness. MMP-2 activity, evaluated by zymography, was increased in Doxo (Control 141338 +/- 8924; Doxo 188874 +/- 7652 arbitrary units; p &lt; 0.001). There were no changes in TNF-alpha, INF-gamma, IL-10, and ICAM-1 myocardial levels. Expression of phospholamban, Serca-2a, and ryanodine receptor did not differ between groups. Conclusion: Acute doxorubicin administration induces in vivo left ventricular dysfunction and in vitro increased myocardial passive stiffness in rats. Cardiac dysfunction is related to myocardial MMP-2 activation. Increased inflammatory stimulation or changed expression of the proteins involved in intracellular calcium transients is not involved in acute cardiac dysfunction.

A feasibility study evaluating docetaxel-based sequential and combination regimens in the adjuvant therapy of node-positive breast cancer

BACKGROUND AND PURPOSE: Docetaxel is an active agent in the treatment of metastatic breast cancer. We evaluated the feasibility of docetaxel-based sequential and combination regimens as adjuvant therapies for patients with node-positive breast cancer. PATIENTS AND METHODS: Three consecutive groups of patients with node-positive breast cancer or locally-advanced disease, aged < or = 70 years, received one of the following regimens: a) sequential A-->T-->CMF: doxorubicin 75 mg/m2 q 3 weeks x 3, followed by docetaxel 100 mg/m2 q 3 weeks x 3, followed by i.v. CMF days 1 + 8 q 4 weeks x 3; b) sequential accelerated A-->T-->CMF: A and T were administered at the same doses q 2 weeks; c) combination therapy: doxorubicin 50 mg/m2 + docetaxel 75 mg/m2 q 3 weeks x 4, followed by CMF x 4. When indicated, radiotherapy was administered during or after CMF, and tamoxifen started after the end of CMF. RESULTS: Seventy-nine patients have been treated. Median age was 48 years. A 30% rate of early treatment discontinuation was observed in patients receiving the sequential accelerated therapy (23% during A-->T), due principally to severe skin toxicity. Median relative dose-intensity was 100% in the three treatment arms. The incidence of G3-G4 major toxicities by treated patients, was as follows: skin toxicity a: 5%; b: 27%; c: 0%; stomatitis a: 20%; b: 20%; c: 3%. The incidence of neutropenic fever was a: 30%; b: 13%; c: 48%. After a median follow-up of 18 months, no late toxicity has been reported. CONCLUSIONS: The accelerated sequential A-->T-->CMF treatment is not feasible due to an excess of skin toxicity. The sequential non accelerated and the combination regimens are feasible and under evaluation in a phase III trial of adjuvant therapy.

3-year results of docetaxel-based sequential and combination regimens in the adjuvant therapy of node-positive breast cancer: a pilot study.

BACKGROUND: Docetaxel has proven efficacy in metastatic breast cancer. In this pilot study, we explored the efficacy/feasibility of docetaxel-based sequential and combination regimens as adjuvant therapy of node-positive breast cancer. PATIENTS AND METHODS: From March 1996 till March 1998, four consecutive groups of patients with stages II and III breast cancer, aged < or = 70 years, received one of the following regimens: a) sequential Doxorubicin (A) --> Docetaxel (T) --> CMF (Cyclophosphamide+Methotrexate+5-Fluorouracil): A 75 mg/m q 3 wks x 3, followed by T100 mg/m2 q 3 wks x 3, followed by i.v. CMF Days 1+8 q 4 wks x 3; b) sequential accelerated A --> T --> CMF: A and T administered at the same doses q 2 wks with Lenograstin support; c) combination therapy: A 50 mg/m2 + T 75 mg/m2 q 3 wks x 4, followed by CMF x 4; d) sequential T --> A --> CMF: T and A, administered as in group a), with the reverse sequence. When indicated, radiotherapy was administered during or after CMF, and Tamoxifen after CMF. RESULTS: Ninety-three patients were treated. The median age was 48 years (29-66) and the median number of positive axillary nodes was 6 (1-25). Tumors were operable in 94% and locally advanced in 6% of cases. Pathological tumor size was >2 cm in 72% of cases. There were 21 relapses, (18 systemic, 3 locoregional) and 11 patients (12%) have died from disease progression. At median follow-up of 39 months (6-57), overall survival (OS) was 87% (95% CI, 79-94%) and disease-free survival (DFS) was 76% (95% CI, 67%-85%). CONCLUSION: The efficacy of these docetaxel-based regimens, in terms of OS and DFS, appears to be at least as good as standard anthracycline-based adjuvant chemotherapy (CT), in similar high-risk patient populations.

Baseline health-related quality-of-life data as prognostic factors in a phase III multicentre study of women with metastatic breast cancer.

The potential value of baseline health-related quality-of-life (HRQOL) and clinical factors in predicting prognosis was examined using data from an international randomised phase III trial which compared doxorubicin and paclitaxel with doxorubicin and cylophosphamide as first line chemotherapy in 275 women with metastatic breast cancer. The European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 and the related breast module (QLQ-BR23) were used to assess baseline HRQOL data. The Cox proportional-hazards regression model was used for both univariate and multivariate analyses of survival. In the univariate analyses, performance status (P<0.001) and number of sites involved (P=0.001) were the most important clinical prognostic factors. The HRQOL variables at baseline most strongly associated with longer survival were better appetite, physical and role functioning, as well as less fatigue (P<0.001). The final multivariate model retained performance status (P<0.001) and appetite loss (P=0.005) as the variables best predicting survival. Substantial loss of appetite was the only independent HRQOL factor predicting poor survival and was strongly correlated (/r/>0.5) with fatigue, role and physical functioning. In addition to known clinical factors, appetite loss appears to be a significant prognostic factor for survival in women with metastatic breast cancer. However, the mechanism underlying this association remains to be precisely defined in future studies.

Mecanismos envolvidos na cardiotoxidade aguda induzida pela doxorrubicina em ratos

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Knocking-Down Cyclin A(2) by siRNA Suppresses Apoptosis and Switches Differentiation Pathways in K562 Cells upon Administration with Doxorubicin

Cyclin A(2) is critical for the initiation of DNA replication, transcription and cell cycle regulation. Cumulative evidences indicate that the deregulation of cyclin A(2) is tightly linked to the chromosomal instability, neoplastic transformation and tumor proliferation. Here we report that treatment of chronic myelogenous leukaemia K562 cells with doxorubicin results in an accumulation of cyclin A(2) and follows by induction of apoptotic cell death. To investigate the potential preclinical relevance, K562 cells were transiently transfected with the siRNA targeting cyclin A(2) by functionalized single wall carbon nanotubes. Knocking down the expression of cyclin A(2) in K562 cells suppressed doxorubicin-induced growth arrest and cell apoptosis. Upon administration with doxorubicin, K562 cells with reduced cyclin A(2) showed a significant decrease in erythroid differentiation, and a small fraction of cells were differentiated along megakaryocytic and monocyte-macrophage pathways. The results demonstrate the pro-apoptotic role of cyclin A(2) and suggest that cyclin A(2) is a key regulator of cell differentiation.

Development of Cationic Solid Lipid Nanoparticles with Factorial Design-Based Studies for Topical Administration of Doxorubicin

Topical chemotherapy using doxorubicin, a powerful anticancer drug, can be used as an alternative with reduced systemic toxicity when treating skin cancer. The aim of the present work was to use factorial design-based studies to develop cationic solid lipid nanoparticles containing doxorubicin; further investigations into the influence of these particles on the drug's cytotoxicity and cellular uptake in B16F10 murine melanoma cells were performed. A 3(2) full factorial design was applied for two different lipid phases; one phase used stearic acid and the other used a 1:2 mixture of stearic acid and glyceryl behenate. The two factors investigated included the ratio between the lipid and the water phase and the ratio between the surfactant (poloxamer) and the co-surfactant (cetylpyridinium chloride). It was observed that the studied factors did not affect the mean diameter or the polydispersity of the obtained nanoparticles; however, they did significantly affect the zeta potential values. Optimised formulations with particle sizes ranging from 251 to 306 nm and positive zeta potentials were selected for doxorubicin incorporation. High entrapment efficiencies were achieved (97%) in formulations with higher amounts of stearic acid, suggesting that cationic charges on doxorubicin molecules may interact with the negative charges in stearic acid. Melanoma culture cell experiments showed that cationic solid lipid nanoparticles without drug were not cytotoxic to melanoma cells. The encapsulation of doxorubicin significantly increased cytotoxicity, indicating the potential of these nanoparticles for the treatment of skin cancer.