Paclitaxel and docetaxel in prostate cancer

Although their ultimate value in prostate cancer therapy remains to be defined in randomized trials, docetaxel and paclitaxel are active agents in HRPC. Combination therapies using either of these taxanes plus oral EMP show reproducible antitumor activity that appears to be greater and more durable than that of single-agent treatment. Although the optimal combination and schedule have not been determined, weekly paclitaxel and EMP and docetaxel given every 3 weeks or by weekly infusion with EMP are useful treatment options for patients with progressive HRPC. The gastrointestinal toxicity of EMP has been reduced by intermittent rather than continuous administration, and other toxicities may be reduced further by use of intravenous EMP. Although there has been progress, the median time to progression of 5 to 6 months for current taxane-based therapies suggests that they will not have major impact on overall survival for patients with HRPC. Greater benefit may be possible earlier in the course of prostate cancer, and the activity of the taxane-EMP combinations is sufficient to justify clinical trials of adjuvant or neoadjuvant chemotherapy for selected groups of patients with locally advanced and poor-prognosis tumors. Armed with many new molecularly targeted agents that may interact favorably with taxanes, it should be possible to build on current antimicrotubule regimens to improve activity in HRPC. Taxane-EMP combinations provide a platform on which to test additional agents that may enhance the apoptotic response or circumvent cellular stress adaptations that confer drug resistance. Further elucidation of signaling pathways that regulate microtubule dynamics and programmed cell death after exposure to microtubule inhibitors would provide a more rational guide for integrating specific inhibitors of signal transduction with current taxane-based therapies. Pharmacokinetic and pharmacodynamic studies will play a key role in the development of future taxane-based therapies for prostate cancer.     

Paclitaxel and pegylated-liposomal doxorubicin are both active in angiosarcoma

BACKGROUND: Paclitaxel has unique activity in angiosarcomas of the face and scalp, but its activity in angiosarcomas originating at other sites is less well defined. Paclitaxel and pegylated-liposomal doxorubicin (PLD) are highly effective in Kaposi sarcoma (KS). Because of the efficacy of PLD in soft tissue sarcoma in general, and in KS in particular, coupled with potential similarities in KS and angiosarcoma, and the apparent activity of paclitaxel in angiosarcomas, the authors treated patients with angiosarcoma with either paclitaxel or PLD as initial chemotherapy. METHODS: To better define the efficacy of these agents in angiosarcoma, the authors reviewed their experience with paclitaxel and PLD in patients with angiosarcoma treated between 1994 and 2004. RESULTS: They identified seven patients with angiosarcoma treated with paclitaxel, and six treated with PLD. Only one patient in the series had an angiosarcoma of the scalp. Two patients receiving paclitaxel had received previous therapy with PLD, and four of six patients treated with PLD had previously received paclitaxel. Of the eight patients treated with paclitaxel, five had major responses (three had partial responses [PR] and two had complete disease remission [CR]) and three had progressive disease (PD). Of the 6 patients who received PLD, 3 had a PR for 6, 19, and >20 months, respectively, 2 had stable disease for 7 and 11 months, respectively, and 1 had PD. CONCLUSIONS: The current study demonstrated the activity of PLD (five of six patients experienced clinical benefit) and extended the data on paclitaxel in angiosarcoma, both of the face and scalp, as well as angiosarcoma originating at other sites.     

High energy shock waves enhance the cytotoxic effect of doxorubicin and methotrexate to human osteosarcoma cell lines

Despite recent advances, the prognosis of relapsed osteosarcoma patients remains very poor. Application of high energy shock waves may change the tumour cell growth and increase the cytotoxic effect of in vivo and in vitro chemotherapeutic agents. We studied the effect of their association with doxorubicin or methotrexate on three in vitro osteosarcoma cell lines. The effect of these combinations on SJSA-1, MG-63 and HOS human osteosarcoma cell lines were evaluated through incubation with doxorubicin or methotrexate and high energy shock wave treatment with 1000 shots at 0.22 mJ/mm(2) and an evaluation of the cell number, cell proliferation and apoptosis at days 1, 3 and 6 from the start of treatment. The combination of high energy shock waves and doxorubicin induced a statistically significant advantage in terms of a decrease in cell number on the SJSA-1 and HOS cell lines, a decrease of cell proliferation on all three cell lines and an increase of apoptosis only on the SJSA-1 cell line. The combination of high energy shock waves with methotrexate induced a decrease of the cell number only in the SJSA-1 and in the HOS cell lines, of the cell proliferation in the SJSA-1 and in the MG-63 cell lines, and an increase of apoptosis only on the SJSA-1 cell line. In conclusion, these experiments show an interesting effect of high energy shock waves on osteosarcoma cell lines, which could lead to future studies of the in vivo effects of high energy shock waves in the murine model as well.     

Effect of pantoprazole to enhance activity of docetaxel against human tumour xenografts by inhibiting autophagy

Background:

Autophagy allows recycling of cellular components and may facilitate cell survival after chemotherapy. Pantoprazole inhibits proton pumps and is reported to inhibit autophagy. Here we evaluate the effects of pantoprazole to modify cytotoxicity of the anticancer drug docetaxel, and underlying mechanisms.

Methods:

Effects of docetaxel±pantoprazole were studied against wild-type and autophagy-deficient PC3 cells and against four human xenografts. Effects of pantoprazole on autophagy were evaluated by quantifying LC3-I, LC3-II and p62 proteins in western blots, and by fluorescent microscopy of cells transfected with RFP-GFP-LC3. The distribution of drug effects and of autophagy was quantified in tumour sections in relation to blood vessels and hypoxia by immunohistochemistry using γH2AX, cleaved caspase-3, Ki67 and LC3/ p62.

Results:

Pantoprazole increased the toxicity of docetaxel in vitro, increased docetaxel-induced expression of γH2AX and cleaved caspase-3, and decreased Ki67 in tumour sections. Pantoprazole increased growth delay of four human xenografts of low, moderate and high sensitivity to docetaxel, with minimal increase in toxicity. Docetaxel led to increased autophagy throughout tumour sections. Pantoprazole inhibited autophagy, and effects of pantoprazole were reduced against genetically modified cells with decreased ability to undergo autophagy.

Conclusions:

Autophagy is a mechanism of resistance to docetaxel chemotherapy that may be modified by pantoprazole to improve therapeutic index.     

Combination of docetaxel and doxorubicin as first-line chemotherapy in metastatic breast cancer.

Docetaxel (Taxotere) and doxorubicin have previously demonstrated a significant antitumor activity in patients with metastatic breast cancer. Furthermore, a lack of cross resistance and overlapping toxicities between the two agents have been reported. In a prospective study, docetaxel (80 mg/m2, 1-hr iv infusion) and doxorubicin (60 mg/m2, 1-hr iv infusion) were administered as first-line chemotherapy in metastatic breast cancer patients to evaluate the clinical efficacy and toxicity of the combination. Forty-three patients were enrolled in the study. The median age was 47 years (range, 30-69). The docetaxel-doxorubicin combination was applied with 3-week intervals until progression. Complete response was achieved in 9 (21.4%) of 42 assessable patients and partial response in 24 (57.2%) patients, for an overall response rate of 78.6%. Median response duration was 8 months (3-18 months). Nausea and vomiting (76%), alopecia (64%), neutropenia (35.7%) and mucositis (33%) were the major side effects of the combination. There was one case of cardiac toxicity. In conclusion, the docetaxel-doxorubicin protocol can be considered as an active regimen for the treatment of patients with metastatic breast cancer with acceptable toxicity and a fairly high response rate.     

In vitro evaluation of schedule-dependent interactions between docetaxel and doxorubicin against human breast and ovarian cancer cells.

Docetaxel, a novel member of the taxoid family, has shown greater potency than paclitaxel in the treatment of advanced breast cancer and certain other solid tumors. The promising clinical activity of docetaxel has also promoted considerable interest in combining this drug with other antitumor agents. In this study, we assessed the cytotoxic interaction between docetaxel and doxorubicin administered at various schedules to human breast and ovarian cancer cells. Through a series of in vitro assays including DNA fragmentation analyses, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays, and flow cytometric analyses, we found that the antagonistic interaction occurred when tumor cells were exposed to the two drugs simultaneously or exposed to doxorubicin before docetaxel. However, no antagonism was observed when docetaxel was added before doxorubicin. Further analyses demonstrated that doxorubicin could interfere with the cytotoxic effect of docetaxel on both mitotic arrest and apoptotic cell death. In addition, biochemical examinations revealed that docetaxel could induce phosphorylation of both bcl-2 and c-raf-1, but these changes were inhibited when tumor cells were pretreated or simultaneously treated with doxorubicin. These results indicate that the interaction between docetaxel and doxorubicin is highly schedule dependent. Exposure of tumor cells to doxorubicin before docetaxel could result in pronounced antagonism. The optimal schedule for this combination might be sequential exposure to docetaxel followed by doxorubicin.     

Nitroglycerin treatment may enhance chemosensitivity to docetaxel and carboplatin in patients with lung adenocarcinoma.

PURPOSE: Nitroglycerin may improve the response to chemotherapy in advanced non-small cell lung cancer. The effects and mechanisms of nitroglycerin on the enhancement of chemosensitivity to docetaxel and carboplatin regimen (DCb) in patients with lung adenocarcinoma have not been reported. EXPERIMENTAL DESIGN: Seventeen patients with operable lung adenocarcinoma and stable angina pectoris were selected to investigate the effects of nitroglycerin on immunoreactivity for hypoxia-inducible factor 1alpha (HIF-1alpha), vascular endothelial growth factor (VEGF), P-glycoprotein (P-gp), the production of which is regulated by HIF-1, and p53 proteins in their resected tumor by semiquantitative immunohistochemical analyses. Eight of 17 patients were treated with nitroglycerin patches before operation, but 9 of 17 patients were not. Furthermore, to study the relationship between changes in plasma VEGF levels by nitroglycerin treatment and response to DCb, 29 patients with advanced lung adenocarcinoma were treated with nitroglycerin for 3 days before chemotherapy using DCb. RESULTS: The rates of immunoreactive cells for HIF-1alpha, VEGF, and P-gp in tumor tissues treated with nitroglycerin were lower than those without nitroglycerin, but those for p53 were not different between those treated with and without nitroglycerin. Furthermore, the rates of immunoreactive cells for VEGF and P-gp proteins were significantly associated with those for HIF-1alpha in tumor tissue. The magnitude of decrease in plasma VEGF levels after treatment with nitroglycerin was significantly associated with response to DCb in patients with advanced lung adenocarcinoma. CONCLUSIONS: Nitroglycerin treatment may improve response to DCb in patients with lung adenocarcinoma, partly through decreasing VEGF and P-gp production via reduction of HIF-1alpha.     

Paclitaxel and doxorubicin combination in the first-line treatment of metastatic breast cancer

Anthracyclines and taxanes are currently the most effective drugs in the treatment of metastatic breast carcinoma. The aim of this study was to determine the efficacy and toxicity of paclitaxel and doxorubicin combination in the first-line treatment of metastatic breast cancer. Forty-five women with metastatic breast cancer were recruited in the study. Median age was 49 years (range, 33-70). Treatment protocol: doxorubicin (50 mg/m2/day, 30-min infusion) followed by paclitaxel (200 mg/m2/day, 3-hr infusion) every 3 weeks. Response rates included complete response in 13 (28.9%) patients and partial response in 19 (42.2%) patients, with an overall response rate of 71%. Five (11%) patients had stable disease and 8 (18%) patients had progressive disease. At a median follow-up of 19.7 months, median time to progression for all patients was 19.9 months (95% confidence interval, 12.8 to 27 months). Median overall survival time was 28.4 months. Grade 3-4 nausea/vomiting and hematological toxicities were observed in 12 (26%) and 6 (13.3%) patients, respectively. Cardiac toxicity was observed in 2 (4.4%) patients. In this trial, paclitaxel and doxorubicin combination was demonstrated to be a favorable and active regimen in the first-line treatment of metastatic breast cancer.     

Phase I trial of pegylated liposomal doxorubicin and docetaxel in advanced breast cancer.

PURPOSE: To develop a combination of pegylated liposomal doxorubicin (Doxil; Alza Pharmaceuticals, Palo Alto, CA) and docetaxel (Taxotere; Aventis Pharmaceutical, Parsipanny, NJ) that can be safely used for the treatment of advanced breast cancer. PATIENTS AND METHODS: Forty-one patients with locally advanced (n = 10) or metastatic (n = 31) breast cancer received Doxil (30-, 40-, or 45-mg/m(2) intravenous [IV] infusion over 30 to 60 minutes), followed 1 hour later by docetaxel (60 or 75 mg/m(2) by IV infusion over 1 hour) in cohorts of three to six patients. Dose-limiting toxicity (DLT) was defined as febrile neutropenia, prolonged neutropenia, or grade 3 to 4 nonhematologic toxicity that occurred during cycle 1. RESULTS: In conjunction with docetaxel 75 mg/m(2) every 4 weeks, the MTD of Doxil was 30 mg/m(2) and required granulocyte colony-stimulating factor (G-CSF) to prevent febrile neutropenia. Without G-CSF, the MTD was docetaxel 60 mg/m(2) and Doxil 30 mg/m(2) every 3 weeks; only 1 (7%) out of 15 patients treated at this dose level had cycle 1 DLT. Infusion reactions were common with Doxil with the recommended infusion schedule during the first cycle (55%) but were reduced with a modified schedule (7%). There was no clinically significant cardiac toxicity. Objective response occurred in eight of nine assessable patients with stage III disease and in 16 (52%) of 31 patients (95% confidence interval, 34% to 70%) with stage IV disease. CONCLUSION: The recommended dose and schedule of this combination for further evaluation is Doxil 30 mg/m(2) and docetaxel 60 mg/m(2) given every 3 weeks without G-CSF. When used with G-CSF, it is Doxil 30 mg/m(2) and docetaxel 75 mg/m(2) every 4 weeks.     

Cellular sensitivity determinants to docetaxel in human gastrointestinal cancers.

beta-tubulin (beta-TUB), Bcl-XL, and additionally glutathione S-transferase pi (GSTpi) were found to participate in sensitivity to docetaxel (TXT) in 7 human gastrointestinal cancer cell lines. The gene expression level of beta-TUB, Bcl-XL, and GSTpi was closely correlated with the IC50 for TXT. beta-TUB amount related to TXT resistance, and GST activity was correlated with IC50 for TXT in the 30-min treatment setting. Bcl-XL transfection increased TXT resistance of COLO201 cells, whereas GST inhibition by ethacrynic acid enhanced TXT cytotoxicity. Continuous TXT treatment increased beta-TUB and GSTpi expression, but the increased GSTpi mRNA was observed in TXT-resistant HCC-48 cells alone.     

Prospective randomized trial of docetaxel versus doxorubicin in patients with metastatic breast cancer.

PURPOSE: This phase III study compared docetaxel and doxorubicin in patients with metastatic breast cancer who had received previous alkylating agent-containing chemotherapy. PATIENTS AND METHODS: Patients were randomized to receive an intravenous infusion of docetaxel 100 mg/m(2) or doxorubicin 75 mg/m(2) every 3 weeks for a maximum of seven treatment cycles. RESULTS: A total of 326 patients were randomized, 165 to receive doxorubicin and 161 to receive docetaxel. Overall, docetaxel produced a significantly higher rate of objective response than did doxorubicin (47.8% v 33.3%; P =.008). Docetaxel was also significantly more active than doxorubicin in patients with negative prognostic factors, such as visceral metastases (objective response, 46% v 29%) and resistance to prior chemotherapy (47% v 25%). Median time to progression was longer in the docetaxel group (26 weeks v 21 weeks; difference not significant). Median overall survival was similar in the two groups (docetaxel, 15 months; doxorubicin, 14 months). There was one death due to infection in each group, and an additional four deaths due to cardiotoxicity in the doxorubicin group. Although neutropenia was similar in both groups, febrile neutropenia and severe infection occurred more frequently in the doxorubicin group. For severe nonhematologic toxicity, the incidences of cardiac toxicity, nausea, vomiting, and stomatitis were higher among patients receiving doxorubicin, whereas diarrhea, neuropathy, fluid retention, and skin and nail changes were higher among patients receiving docetaxel. CONCLUSION: The observed differences in activity and toxicity profiles provide a basis for therapy choice and confirms the rationale for combination studies in early breast cancer.     

Pegylated liposome-encapsulated doxorubicin and cisplatin enhance the effect of radiotherapy in a tumor xenograft model.

Concomitant chemotherapy and radiotherapy (CCRT) has recently been shown to improve treatment outcome in a range of solid tumors. Pegylated liposomes have the potential to target drugs directly to tumors and may increase the efficacy and reduce the toxicity of CCRT by selectively delivering radiosensitizing agents to tumor, as opposed to normal, tissues. In these studies, we have assessed CCRT using pegylated liposome encapsulated doxorubicin (PLED) and pegylated liposome encapsulated cisplatin (PLEC) against KB head and neck cancer xenograft tumors in nude mice. The addition of low-dose (2 mg/kg) PLED (P < 0.001) and PLEC (P < 0.001) significantly increased the effect of 4.5 Gy, but not 9 Gy, single-fraction radiotherapy (SFRT). Both PLED and PLEC were significantly more effective than their unencapsulated counterparts in increasing the effect of SFRT. In addition, PLED (P < 0.001) and PLEC (P < 0.05) significantly increased the effect of fractionated radiotherapy (9 Gy in 3 fractions) in two different dosing schedules (2 mg/kg single dose or three sequential doses of 0.67 mg/kg). Unencapsulated diethylenetriaminepentaacetic acid and pegylated liposomal diethylenetriaminepentaacetic acid were used as controls to test the effect of the liposome vehicle and showed no interaction with 4.5 Gy or 9 Gy SFRT (P > 0.1). CCRT was well-tolerated, with no evidence of increased local or systemic toxicity, as compared with radiotherapy alone. This study is the first to demonstrate the value of pegylated liposomes as vehicles for the delivery of radiosensitizing drugs in CCRT strategies.     

Maximized reduction of primary breast tumor size using preoperative chemotherapy with doxorubicin and docetaxel.

PURPOSE: To assess the toxicity and efficacy of preoperative chemotherapy with doxorubicin and docetaxel in patients with primary operable breast cancer. PATIENTS AND METHODS: Forty-two patients with histologically confirmed primary breast cancer tumors of at least 2 cm in diameter received doxorubicin (50 mg/m(2) intravenously [IV] over 15 minutes) and docetaxel (75 mg/m(2) IV over 1 hour) every 14 (24 patients) or 21 (18 patients) days for four cycles. RESULTS: The median size of the primary tumor decreased significantly, from 4 cm (range, 2 to 10 cm) to 2 cm (range, 0 to 5 cm) on physical examination and from 3.4 cm (range, 1 to 8 cm) to 1. 8 cm (range, 0 to 4 cm) on sonography (P <.001). The overall response rate as assessed by physical examination was 93%, and complete remission of the primary tumor occurred in 33% of patients. The remission rate as assessed by sonographic measurement was 67%. Two patients (5%) had histologically confirmed complete responses. Sonography was more reliable than palpation in predicting histologically determined response. No grade 4 toxicity was noted, and grade 3 toxicity was reported with alopecia (95%), lethargy (17%), loss of appetite (10%), stomatitis (7%), leukopenia (5%), skin desquamation (5%), infection (5%), motor neuropathy (2%), and nausea (2%). The 3-week schedule was associated with less toxicity than the 2-week schedule. CONCLUSION: Preoperative combination chemotherapy with doxorubicin and docetaxel is highly effective and feasible in primary operable breast cancer.     

A phase-III trial of doxorubicin and docetaxel versus doxorubicin and paclitaxel in metastatic breast cancer: results of the ERASME 3 study

PURPOSE: In first-line metastatic breast cancer, both paclitaxel (P)-doxorubicin (A) and docetaxel (D)-doxorubicin (A) combinations have shown superiority over treatments without taxane. The aim of this study was to compare the two combinations. PATIENTS AND METHODS: Chemotherapy-naive (except for adjuvant therapy) metastatic breast cancer patients were randomly assigned to intravenous AD (arm D) or AP (arm P) every 3 weeks for a maximum of four cycles, then four cycles of single agent docetaxel (arm D) or paclitaxel (arm P). Primary endpoint was overall quality of life (QoL) measured by EORTC QLQ-C30 after four courses of doxorubicin-taxane combination. Secondary endpoints were toxicity, overall survival (OS), progression-free survival (PFS), and QoL sub-scores. RESULTS: Between March 2000 and April 2004, 210 patients were randomized: 103 to arm P and 107 to arm D. Patient characteristics were well balanced between arms. After four courses, QoL score differences between groups or compared to baseline scores were not significant. Response rate was 39.6% for AD and 41.8% for AP. After a median follow-up of 50.2 months, median PFS and median OS were 8.7 and 21.4 months in arm D and 8.0 and 27.3 months in arm P (p = 0.977 and 0.081, respectively). Hematological toxicity was significantly more frequent in arm D than in arm P (p < 10(-6)), as well as grades 3-4 asthenia (p = 0.03). Neuropathy occurred more frequently in arm P (p = 0.03). CONCLUSION: In this study, paclitaxel or docetaxel combined with doxorubicin were not significantly different in terms of QoL scores and efficacy, but had different toxicity profiles.     

Paclitaxel and carboplatin in the treatment of small-cell lung cancer patients resistant to cyclophosphamide, doxorubicin, and etoposide: a non-cross-resistant schedule.

PURPOSE: To evaluate the efficacy of paclitaxel and carboplatin (PC) in small-cell lung cancer (SCLC) patients resistant to cyclophosphamide, doxorubicin, and etoposide (CDE). PATIENTS AND METHODS: We performed a phase II study with PC in SCLC patients who relapsed within 3 months after first-line treatment with CDE. Paclitaxel administration (175 mg/m2 by a 3-hour intravenous infusion) was followed by a 30-minute infusion of carboplatin (area under the curve 7; Chatelut formula) once every 3 weeks for five cycles. Dexamethasone, clemastine, and ranitidine were standard premedication before every cycle. RESULTS: Included were 35 patients (median age, 59 years; 16 with limited disease and 19 with extensive disease; Eastern Cooperative Oncology Group performance status of < or = 1; median time off treatment 6 weeks) who were previously treated with CDE (n = 33), oral etoposide (n = 2), and reinduction CDE (n = 15); only one patient had received three CDE treatments of five cycles. The CDE regimen was followed by local thoracic radiotherapy in seven patients. Hematologic toxicity of grade 3 or 4, for leukopenia was 27% and 6%, for thrombocytopenia 21% and 13%, and for anemia 17% and 0%, respectively, for a total of 132 cycles. Two patients had neutropenic fever; no toxic death occurred. Nonhematologic toxicity was paresthesia CTC grade 3, diarrhea grade 4, and myalgia grade 3 in one patient each. Reversible paresthesia (CTC grade 1 and 2) in toes and fingers was reported in 69% of patients. Thirty-four patients were assessable for response: complete response in two patients, partial response in 23 patients, stable disease in eight patients, and progressive disease in one patient (response rate, 73.5%; 95% confidence interval, 59% to 88%). One patient was found to have atypical carcinoid at pathologic review and was excluded. Median time to progression was 21 weeks (range, 3 to 40 weeks). Median survival was 31 weeks (range, 6 to 112 weeks). One-year survival was 9%. CONCLUSION: Second-line PC in CDE-resistant SCLC patients yields a high response rate and seems non-cross-resistant to CDE. Toxicity was mild in these poor-prognosis patients.     

Pharmacokinetic interactions of paclitaxel, docetaxel and their vehicles with doxorubicin

Background: The combination of doxorubicin (Dx) with paclitaxel or docetaxel is clinically effective but there are concerns regarding the higher incidence of cardiotoxicity of the combination compared with Dx alone. The mechanism of the increased toxicity is still unclear.Purpose: To assess whether there is a pharmacokinetic interaction between paclitaxel, docetaxel or their vehicles and Dx in mice.Materials and methods: CDF1 male mice were treated with Dx either alone (10 mg/kg i.v.) or in combination with paclitaxel (25 mg/kg) or docetaxel (25 mg/kg) or their vehicles, i.e., cremophor-ethanol-glucose (cremophor) or polysorbate80-ethanol-glucose (polysorbate). Four mice were killed 4, 8 or 24 hours after Dx in each experimental group and Dx was assayed in serum and in heart, liver, kidney and spleen by HPLC.Results: Four hours after treatment the concentrations of Dx in heart, liver and kidney were much higher in mice concomitantly treated with paclitaxel, docetaxel (dissolved in either cremophor or polysorbate) and cremophor. At subsequent times the differences were modest and only reached statistical significance in a few cases.Dx metabolites were modified by concomitant treatment with taxanes or their vehicles. In particular, the levels of Dx aglycone in liver and kidney were significantly lower in mice treated with the combination than in mice given Dx alone.Conclusions: paclitaxel, docetaxel and cremophor when given together with Dx modify its distribution and metabolism, increasing Dx levels in many tissues including the heart. This might have some bearing on the toxicity of regimens in which Dx is combined with taxanes.     

Neoadjuvant docetaxel followed by adjuvant doxorubicin and cyclophosphamide in patients with stage III breast cancer.

BACKGROUND: To evaluate clinical and pathologic response to neoadjuvant docetaxel therapy in patients with stage III breast cancer. Patients and methods: Forty-five patients were planned to receive four cycles of docetaxel 100 mg/m2 every 3 weeks, followed by surgery, four cycles of doxorubicin 60 mg/m2 and cyclophosphamide 600 mg/m2 (AC) every 3 weeks, radiation therapy (RT), and tamoxifen when indicated. RESULTS: After four cycles of neoadjuvant docetaxel, the clinical response rate within the breast was 59% (95% CI 42% to 73%) and overall (breast and axilla) was 49% (95% CI 38% to 72%) in the intention-to-treat (ITT) population. At the time of surgery, 10% (n=4) of patients had a pathologic complete response (pCR) in the breast, 27% (n=11) had a pCR within the axillary lymph nodes, and 7% (n=3) had a pCR in the breast and axilla (95% CI 2% to 21%). An additional 5% (n=2) had minimal residual invasive tumor (<5 mm). The 5-year overall survival rate was 80%. The percentage of patients with grade 3/4 neutropenia was similar during docetaxel (93%) and AC (86%), while a greater percentage of patients had febrile neutropenia during docetaxel treatment (27%) compared with AC treatment (7%). CONCLUSIONS: Neoadjuvant docetaxel followed by surgery, adjuvant AC, hormonal therapy where indicated, and RT is an active regimen for patients with stage III breast cancer.     

Uptake,metabolism, and cytotoxicity of doxorubicin in human Ewing's sarcoma and rhabdomyosarcoma cells

Summary Uptake, metabolism, and cytotoxicity of doxorubicin (DOX) in human Ewing's sarcoma (ES) and rhabdomyosarcoma (RS) cells were examined. Cellular uptake of DOX was determined by liquid scintillation spectrometry, and intracellular metabolism was examined by high performance liquid chromatography. The cytotoxicity of DOX was assessed by two different methods: an extracellular matrix detachment assay (ECM-D) and ³H-thymidine incorporation. The uptake of DOX by ES cells was 1.5–3.0 times greater than RS cells, even though both cell types achieved intracellular steady-state concentrations between 6–8 h. No significant intracellular metabolism (< 5%) was seen after 8-h incubations with the drug. The cytotoxic effects of DOX in both cell lines were concentration-dependent, with the RS cells being more sensitive. Measurement of ¹⁴C-DOX appears to be a reliable method for quantitating intracellular DOX. In addition, the ECM-D and ³H-thymidine assays used for assessing cytotoxicity produced similar results, showing that the ECM-D can be a reliable and easily performed test of cell death.This research was partially supported by the Louis R. Lurie Foundation and the Fred Gellert Foundation