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Biomedical subjects

V Valero

Publications and source records attributed to V Valero.

At least 37 records · Page 2Linked to original sources
PubMed2001

Canalicular stenosis secondary to docetaxel (taxotere): a newly recognized side effect.

OBJECTIVE: To report a newly recognized side effect of a commonly used antineoplastic agent, docetaxel, in three patients with metastatic breast cancer. DESIGN: Observational case reports. PARTICIPANTS: Three patients with metastatic breast cancer who received weekly docetaxel chemotherapy. MAIN OUTCOME MEASURES: Occurrence of epiphora and severity of punctal and canalicular fibrosis secondary to docetaxel. RESULTS: In three patients receiving weekly docetaxel, canalicular stenosis and resultant epiphora developed shortly after start of their treatment. Discontinuation of drug several months after initiation of therapy did not lead to resolution of symptoms in two of the three patients. CONCLUSIONS: Epiphora is a newly recognized side effect of docetaxel and may occur more frequently with weekly cycles of this drug. The mechanism for epiphora seems to be punctal and canalicular stenosis. This side effect, in advanced cases, is not reversible with discontinuation of the drug. Patients being administered weekly cycles of docetaxel should be screened for epiphora and canalicular stenosis, and treatment in the form of silicone intubation or punctoplasty should be considered in early stages to prevent the need for conjunctivodacryocystorhinostomy.

Adult↗
PubMed2001

Phase I-II vinorelbine (Navelbine) by continuous infusion in patients with metastatic breast cancer: cumulative toxicities limit dose escalation.

Vinorelbine (Navelbine) has significant activity against breast carcinoma and is less neurotoxic than vinblastine. Because vinblastine has improved activity when administered by continuous infusion, we conducted a Phase I-II study to determine the maximum tolerated dose (MTD) of vinorelbine when given by continuous infusion and the response rates to it in heavily pretreated metastatic breast cancer patients. Between April 1994 and August 1997, 87 patients were entered in the study. All were female and had proven metastatic breast cancer. Ninety-five percent of them had received prior doxorubicin treatment, and 74% had received prior paclitaxel treatment. In Phase I of the study, all patients received 8 mg of vinorelbine by intravenous (i.v.) bolus followed by a continuous infusion of vinorelbine over 96 hr. When the MTD was determined, patients were entered in the Phase II arm to assess treatment responses and cumulative toxic reactions. In the Phase I arm (43 patients, 182 cycles), we determined the MTD of vinorelbine to be 8 mg by i.v. bolus followed by a continuous infusion of 11 mg/m2/day over 4 days. The dose-limiting toxic reaction was grade 3-4 granulocytopenia in 35% of the cycles and neutropenic fever in 15% of the cycles. Forty-four patients (193 cycles) were treated at the MTD. Seven (16%) of them had a response (2 complete responses, 5 partial responses). The median durations of response and survival were 4.3 and 8.6 months, respectively. However, cumulative toxic reactions (neutropenic fever and stomatitis) in 22 patients (50%) required dose reductions. A continuous infusion of vinorelbine can be safely administered but with a narrow therapeutic index because of cumulative toxic reactions. We recommend a modified MTD of vinorelbine: 8 mg by i.v. bolus followed by a continuous infusion of 10 mg/m2/day over 4 days. However, this treatment schedule offers no apparent advantage over the commonly used weekly vinorelbine schedule.

Adult↗
PubMed2001

Chemotherapy of metastatic breast cancer: what to expect in 2001 and beyond.

Chemotherapy plays an important role in the management of metastatic breast cancer. The anthracyclines (doxorubicin, epirubicin) and the taxanes (paclitaxel, docetaxel) are considered the most active agents for patients with advanced breast cancer. Traditionally, the anthracyclines have been used in combination with cyclophosphamide and 5-fluorouracil (FAC, FEC). The taxanes have single-agent activity similar to older combination chemotherapy treatments. There is great interest in developing anthracycline/taxane combinations. Capecitabine is indicated for patients who progress after anthracycline and taxane therapy. Vinorelbine and gemcitabine have activity in patients with metastatic breast cancer and are commonly used as third- and fourth-line palliative therapy. The role of high-dose chemotherapy is not well-defined and remains experimental. Novel cytotoxic therapy strategies include the development of anthracycline, taxane, and oral fluoropyrimidine analogues; antifolates; topoisomerase I inhibitors, and multidrug resistance inhibitors. A better understanding of the biology of breast cancer is providing novel treatment approaches. Oncogenes and tumor-supressor genes are emerging as important targets for therapy. Trastuzumab, a monoclonal antibody directed against the Her-2/neu protein, has been shown to prolong survival in patients with metastatic breast cancer. Other novel biologic therapies interfere with signal transduction pathways and angiogenesis. The challenge for the next decade will be to integrate these promising agents in the management of metastatic and primary breast cancer.

Antibodies, Monoclonal↗
PubMed2001

Doxorubicin and taxane combination regimens for metastatic breast cancer: focus on cardiac effects.

Investigation of the combination of the taxanes with doxorubicin in the treatment of breast cancer has logically progressed, with the ultimate goal of identifying a safe and effective regimen for use in the adjuvant setting. Initial phase II findings of the concurrent doxorubicin/paclitaxel combination resulted in substantial response rates, but at a high cost. A much higher percentage of patients than expected developed anthracycline-induced cardiomyopathy. Subsequent phase II and phase III trials have determined administration schedules of doxorubicin/paclitaxel that reduce the risk for cardiotoxicity. However, the overall response rate is only modestly improved over sequential single-agent therapy or standard doxorubicin-containing combination therapy. The lack of cardiotoxicity with docetaxel, its high antitumor activity, and its linear pharmacokinetics have made it an attractive taxane for combination with doxorubicin. In addition, it is easily administered in the outpatient setting. Phase I/II trials of the combination of doxorubicin/docetaxel resulted in high response rates with a lack of adverse modification of anthracycline-induced cardiomyopathy. These findings have been confirmed in a large phase III randomized trial where overall response rates and time to disease progression were significantly improved, but the incidence of cardiomyopathy was not different for the doxorubicin/docetaxel versus doxorubicin/cyclophosphamide (AC) regimen. Ongoing studies are underway to assess the role of the doxorubicin/docetaxel combination in the adjuvant setting as primary chemotherapy in the neoadjuvant setting. It is here that the most benefit on survival of breast cancer patients is likely to be shown. At the same time, it is in the adjuvant setting where the absence of potentially late cardiac and other toxicities must be assured.

Antibiotics, Antineoplastic↗
PubMed2000

Phase II study of paclitaxel in patients with metastatic breast carcinoma refractory to standard chemotherapy.

BACKGROUND: The authors conducted a single institution Phase II clinical trial to determine whether paclitaxel had antitumor activity in patients with metastatic breast carcinoma that was refractory to standard chemotherapy. METHODS: Patients with metastatic breast carcinoma were eligible for the study if they had disease progression after at least 2 prior chemotherapy regimens. Patients who had received three prior regimens were treated in a separate cohort. All patients were required to have received doxorubicin in the past and were not eligible if they had received prior therapy with paclitaxel. The starting dose of paclitaxel for low risk patients was 175 mg/m2, administered as a 24-hour continuous infusion; the starting dose of paclitaxel was 150 mg/m2 for patients who had received > or = 3 prior regimens. Therapy was given every 3 weeks and continued for at least 2 courses unless there was evidence of rapidly progressing disease, for at least 3 courses if there was no change in disease and Grade 3 or 4 (based on National Cancer Institute toxicity criteria) toxicity was not noted, and for 6 courses beyond the maximum response in patients who demonstrated complete or partial responses and showed no evidence of disease progression. RESULTS: Sixty-eight of 69 patients entered in the study were evaluable for response: 35 patients who had received 2 prior chemotherapy regimens for Stage IV disease and 33 patients who had received > or =3 prior regimens. A partial response was observed in 7 patients who had received 2 prior regimens, for an objective response rate of 20% (95% confidence interval [95% CI], 14-26%). In the group who had received > or = 3 prior regimens, a total of 6 partial responses were observed, for an objective response rate of 18% (95% CI, 12-23%). The median response duration was 8.2 months (range, 2.7-10.1 months) for the group who had received 2 prior regimens and 5.8 months (range, 2.1-9.5 months) for patients who received > or = 3 prior regimens. Responses were noted in patients with anthracycline-resistant tumors. CONCLUSIONS: Paclitaxel was active in heavily pretreated patients with metastatic breast carcinoma, including anthracycline-resistant breast carcinoma.

Adult↗
PubMed2000

Combined modality treatment of locally advanced breast carcinoma in elderly patients or patients with severe comorbid conditions using tamoxifen as the primary therapy.

BACKGROUND: The purpose of the current study was to evaluate the objective response rate and possibility of breast-conserving surgery using neoadjuvant tamoxifen in the multimodality treatment, including surgery and radiotherapy, of elderly or frail patients with locally advanced breast carcinoma. METHODS: Forty-seven patients age > 75 years or age < 75 years with comorbid conditions and locally advanced breast carcinoma were treated with neoadjuvant tamoxifen (20 mg/day) for 3-6 months. This was followed by surgery and radiotherapy when feasible and adjuvant tamoxifen for 5 years or until disease recurrence. RESULTS: The median age of the patients was 72 years (range, 48-86 years). Approximately 22% had T3 lesions, 57% had T4 lesions, 22% were Stage II (AJCC Manual for Staging Cancer, 3rd edition), and 78% were Stage III. Eighty percent were estrogen receptor positive. After 6 months of treatment with neoadjuvant tamoxifen, a response rate of 47% was observed, including a complete response rate of 6%. Twenty-nine patients (62%) were rendered free of disease by surgery, including 5 with breast-conserving procedures. After a median follow-up of 40 months, 23 patients (49%) remained disease free. The median survival time had not been reached at the time of last follow-up. No major toxicity was observed, with the exception of one patient who developed a possible tamoxifen-related Stage I endometrial carcinoma. The estimated 2-year and 5-year progression free and overall survival rates were 50% and 41%, and 83% and 59%, respectively. CONCLUSIONS: The results of the current study show that neoadjuvant tamoxifen was effective in the treatment of elderly or frail patients with locally advanced breast carcinoma with estrogen receptor positive tumors, and resulted in a reasonable response rate, including complete responses and good overall survival.

Age Factors↗
PubMed2000

Minority cancer patients and their providers: pain management attitudes and practice.

BACKGROUND: The goals of the current studies were: 1) to determine the pain treatment needs of socioeconomically disadvantaged African-American and Hispanic patients with recurrent or metastatic cancer and 2) to assess the attitudes of health care professionals who treat them. METHODS: In the first study 108 African-American and Hispanic patients with metastatic or recurrent cancer and pain completed a survey about their pain intensity, pain interference, and attitudes toward analgesic medications. Physicians also rated their patients' pain and the adequacy of the patients' current analgesic prescriptions was assessed. In the second study 55 physicians and nurses who treat these patients completed a questionnaire regarding cancer pain and its management in their practice settings. RESULTS: Approximately 28% of the Hispanic and 31% of the African-American patients received analgesics of insufficient strength to manage their pain. Although the majority of patients received appropriate analgesics, 65% reported severe pain. Physicians underestimated pain severity for 64% of the Hispanic and 74% of the African-American patients. Physicians were more likely to underestimate the pain severity of female patients than male patients. Inadequate pain assessment, patient reluctance to report pain, and lack of staff time were perceived as barriers to pain management. CONCLUSIONS: Although the data suggest recent improvements in analgesic prescribing practices for African-American and Hispanic cancer patients, the majority of patients reported high levels of pain and limited pain relief from analgesic medications. Inadequate pain assessment remains a major barrier to optimal cancer pain treatment.

Adult↗
PubMed2000

Randomized trial of high-dose chemotherapy and blood cell autografts for high-risk primary breast carcinoma.

BACKGROUND: Uncontrolled studies have reported encouraging outcomes for patients with high-risk primary breast cancer treated with high-dose chemotherapy and autologous hematopoietic stem cell support. We conducted a prospective randomized trial to compare standard-dose chemotherapy with the same therapy followed by high-dose chemotherapy. PATIENTS AND METHODS: Patients with 10 or more positive axillary lymph nodes after primary breast surgery or patients with four or more positive lymph nodes after four cycles of primary (neoadjuvant) chemotherapy were eligible. All patients were to receive eight cycles of 5-fluorouracil, doxorubicin (Adriamycin), and cyclophosphamide (FAC). Patients were stratified by stage and randomly assigned to receive two cycles of high-dose cyclophosphamide, etoposide, and cisplatin with autologous hematopoietic stem cell support or no additional chemotherapy. Tamoxifen was planned for postmenopausal patients with estrogen receptor-positive tumors and chest wall radiotherapy was planned for all. All P values are from two-sided tests. RESULTS: Seventy-eight patients (48 after primary surgery and 30 after primary chemotherapy) were registered. Thirty-nine patients were randomly assigned to FAC and 39 to FAC followed by high-dose chemotherapy. After a median follow-up of 6.5 years, there have been 41 relapses. In intention-to-treat analyses, estimated 3-year relapse-free survival rates were 62% and 48% for FAC and FAC/high-dose chemotherapy, respectively (P =.35), and 3-year survival rates were 77% and 58%, respectively (P =.23). Overall, there was greater and more frequent morbidity associated with high-dose chemotherapy than with FAC; there was one septic death associated with high-dose chemotherapy. CONCLUSIONS: No relapse-free or overall survival advantage was associated with the use of high-dose chemotherapy, and morbidity was increased with its use. Thus, high-dose chemotherapy is not indicated outside a clinical trial.

Adult↗
PubMed2000

Colitis associated with docetaxel-based chemotherapy in patients with metastatic breast cancer.

BACKGROUND: Docetaxel and vinorelbine as combined treatment for metastatic breast cancer can have the dose-limiting toxic effects of mucositis and neutropenic fever. We report unexpected ischaemic colitis in six patients associated with docetaxel-based therapy, three of whom were treated in a phase I study designed to establish the maximum tolerated dose of this combination with the prophylactic use of granulocyte-colony-stimulating factor. METHODS: Between August, 1997, and December, 1998, 14 patients with metastatic breast cancer were treated with vinorelbine, docetaxel, and granulocyte-colony-stimulating factor in a phase I study. Three patients developed colitis similar to that seen in typhlitis. Three additional patients were identified during scheduled review of toxic effects in patients participating in clinical trials involving docetaxel. FINDINGS: Three patients on combined vinorelbine and docetaxel developed colitis-like symptoms. Two patients died, one from necrotic bowel and the other from neutropenic fever and colitis. Two of the patients presented on day 7 and day 8 of chemotherapy, respectively, with neutropenic fever and abdominal pain; the third patient developed neutropenia without fever and abdominal pain on day 8. The other three patients were treated with docetaxel, docetaxel and pamidronate disodium, or docetaxel and cyclophosphamide. All three patients presented with abdominal pain on days 10, 5, and 4, respectively. One had non-neutropenic fever, another had neutropenic fever, and the third was afebrile and non-neutropenic at the time of presentation with abdominal pain. Three patients had blood in their diarrhoea, abdominal tenderness, or both. Computed tomography of the abdomen and pelvis showed features of colitis in three patients. INTERPRETATION: This serious complication may result from the use of docetaxel and may be exacerbated by its combination with vinorelbine. Study of hospital-based patients treated with taxane-based chemotherapy is underway to find out the frequency of such complications.

Aged↗
PubMed2000

A unified definition of clinical anthracycline resistance breast cancer.

The purpose of the study was to determine the response rates (RR) and duration to second- and third-line chemotherapy programmes in patients with anthracycline-resistant breast cancer, utilizing various definitions of anthracycline resistance. This was a retrospective analysis performed on 1335 patients with metastatic breast cancer who participated in consecutive clinical trials of first line, anthracycline-containing combination chemotherapy (ACCC) at the University of Texas MD Anderson Cancer Center between July 1973 and April 1980. Anthracycline-resistant groups were identified using definitions of anthracycline resistance found in the literature: progressive disease as best response to ACCC (Group 1, n = 56 patients); progressive disease while receiving ACCC after an intervening response to the drug (Group 2, n = 84); progressive disease within 6 months of last dose of ACCC (Group 3, n = 233); and progressive disease within 12 months of last dose of ACCC (Group 4, n = 272). Second- and third-line therapies administered to these patients included methotrexate, doxorubicin, mitoxantrone, bisantrene, vinblastine, vindesine, melphalan, mitomycin, cisplatin, etoposide and others, but not taxanes. The distribution of patients' characteristics was similar between the four groups, as was the use of second- and third-line regimens. Response rate (RR) to second-line chemotherapy were 5% and 7.7% for Group 1 and Group 2 respectively. In contrast, RR to second-line chemotherapy were 21.6% and 15% for Group 3 and 4. The differences in response rate between the combination of Groups 1 and 2 and Groups 3 or 4 were significant (P = 0.005 and P = 0.04 respectively). These results indicate that strictly defined anthracycline resistance as defined in Groups 1 and 2 is associated with resistance to many other cytotoxic drugs. The definitions used in Groups 3 and 4 include many patients with responsive tumours, and a more favourable prognosis.

Adult↗
PubMed2000

Phase I study of vinorelbine by 96-hour infusion in advanced metastatic breast cancer.

The purpose of this study was to evaluate the maximum tolerated dose and the toxicity profile of vinorelbine administered by continuous infusion for 96 hours to patients who had received prior chemotherapy for metastatic breast cancer. Forty-three patients with metastatic breast cancer were treated with vinorelbine 8 mg intravenously for 10 minutes (day 1) followed by continuous infusion of vinorelbine for 96 hours. Treatments were repeated every 3 weeks. Eighty-eight percent of the patients had had two or more prior chemotherapeutic regimens: 91% had prior doxorubicin therapy and 77% had prior paclitaxel therapy. All 43 patients were evaluable for toxicity. The median age was 49 years. All patients had a performance status less than or equal to 2 and a life expectancy more than 12 weeks. Eight dose levels were evaluated, and a total of 182 cycles were given. National Cancer Institute grade III or IV granulocytopenia was observed in 64 (35%) cycles, neutropenic fever in 27 (15%) cycles, fatigue (National Cancer Institute grade III or IV) in 18 (10%) cycles, and hand-foot syndrome in 8 (4%) cycles. In 17 (9%) cycles, patients were hospitalized. The maximum tolerated dose of this regimen was determined to be vinorelbine 8 mg intravenously for 10 minutes (day 1) followed by continuous vinorelbine infusion 11 mg/m2 for 96 hours. The dose-limiting toxicity was neutropenic fever and stomatitis.

Adult↗
PubMed2000

Risks and benefits of taxanes in breast and ovarian cancer.

The taxanes are a unique class of agents with a broad spectrum of clinical activity. They act by binding to tubulin, producing unnaturally stable microtubules and subsequent cell death. The distribution and elimination of paclitaxel depend on dose and administration rate. This nonlinearity is much less evident at lower infusion rates (24-hour infusions) and more evident at high plasma concentrations (3-hour infusions). The pharmacokinetics of docetaxel also suggest the presence of nonlinear pathways, but these appear to be clinically insignificant at the current doses utilised (60 to 100 mg/m2). Both agents undergo hepatic metabolism and biliary excretion and require dose adjustment in the setting of liver dysfunction. Drug interactions are quite common with these agents, some of which are sequence-dependent and clinically significant. The optimal dose of paclitaxel is not known at this time, and controversy over possible dose- or schedule-related differences in efficacy still remain. Docetaxel is somewhat more consistent in its dose and scheduling information, but controversy remains regarding a dose-benefit relationship as well as scheduling differences (weekly vs every 3 weeks). Toxicity profiles for these agents are somewhat different. Paclitaxel is more likely to be associated with peripheral neuropathy and myalgias/arthralgias than docetaxel. Docetaxel is more likely to be associated with a cumulative fluid retention syndrome that can be dose limiting. Paclitaxel and docetaxel are both highly active agents against breast cancer, including tumours that are resistant to anthracyclines. Docetaxel tends to have higher response rates overall, but direct comparisons at maximally tolerated doses have not been completed. Combination regimens with many different agents are attempting to improve on the responses seen with single-agent taxanes. The combination of paclitaxel and a platinum compound should be utilised as first-line therapy of advanced ovarian cancer. Controversy lies in the choice of the platinum compound and the dose and administration schedule of paclitaxel. Substitution of docetaxel for paclitaxel in these platinum-containing regimens is also being investigated. The taxanes also exhibit activity against ovarian cancer in patients previously exposed to platinum agents. These agents may also be administered intraperitoneally for local therapy of metastatic ovarian cancer. Although docetaxel and paclitaxel are often considered similar in activity and tolerability, this review emphasises the fact that these agents are indeed different. Clinicians need to be familiar with the benefits and adverse events related to each agent in order to make informed, appropriate clinical decisions.

Antineoplastic Agents, Phytogenic↗
PubMed1999

Phase II study of vinorelbine administered by 96-hour infusion in patients with advanced breast carcinoma.

BACKGROUND: Vinorelbine given by weekly bolus injection is active and less toxic than bolus vinblastine in the treatment of patients with metastatic breast carcinoma. Vinblastine given by 5-day continuous infusion showed a steep dose-response curve. Pharmacokinetic studies of vinorelbine showed that it is possible to achieve a comparable antitumor effect with a smaller amount of the drug if it is given by continuous infusion. The purpose of this study was to determine the efficacy of vinorelbine given by 96-hour continuous infusion to patients with refractory metastatic breast carcinoma patients. METHODS: Between May 1996 and August 1997, 47 patients with metastatic breast carcinoma were registered into the study. All patients previously had received doxorubicin and 70% had undergone prior paclitaxel treatment. Approximately 56% of the patients had >/=2 metastatic sites. All patients received vinorelbine according to the following dose schedule: 8 mg bolus followed by 11 mg/m(2) by continuous infusion over 24 hours every 4 days every 3 weeks. RESULTS: Forty-four patients were evaluable for response. A total of 193 cycles were administered. The overall response rate was 16% (2 patients achieved a complete response and 5 patients achieved a partial response). The median duration of response was 4.3 months and the median overall survival was 8.6 months. Patients with visceral metastases and/or multiple sites of involvement had shorter durations of response than patients with only soft tissue disease or single-site metastasis (3.1 months vs. 4. 9 months) and shorter overall survival (8.1 months vs. 12 months). Dose reductions were necessary due to cumulative stomatitis and/or fatigue in 12 cycles and neutropenia and/or infection in 13 cycles. CONCLUSIONS: Due to toxicity, a revised maximum tolerated dose for continuous infusion vinorelbine is proposed by the authors: 8 mg intravenously over 10 minutes followed by 10 mg/m(2) by continuous infusion over 24 hours every 4 days. The current dose schedule did not offer an advantage either in response rates or survival over the weekly vinorelbine bolus injection in doxorubicin-resistant and paclitaxel-resistant patients.

Adult↗
PubMed1999

Phase I/II trial of high dose mitoxantrone in metastatic breast cancer: the M.D. Anderson Cancer Center experience.

Anthracyclines are among the most active agents in metastatic breast cancer. Mitoxantrone demonstrated a different toxicity profile when compared to doxorubicin. We performed a phase I/II study of single-agent high-dose mitoxantrone therapy for advanced breast cancer. Nineteen patients who had a diagnosis of metastatic breast cancer received treatment at the M.D. Anderson Cancer Center between June 1986 and December 1987. The patients received escalating doses of mitoxantrone until a maximum tolerated dose (MTD), defined as grade 3 or 4 nonhematologic toxicity or infection, was obtained. The starting dose of 25 mg/m2, given by short intravenous infusion, was escalated by 25% in each five-patient cohort if each patient in the previous cohort tolerated the initial course and 2 or fewer patients reached the MTD. The median cumulative dose of mitoxantrone was 93 mg/m2 (range, 25-205) and the maximum single dose was 39 mg/m2. Myelosuppression was the dose limiting toxicity. The median duration of granulocyte count < or = 250/microl was 5-7 days. Four patients (22%) had infections that required hospitalization, 3 patients (17%) had cardiac toxicity. One patient (6%) achieved a complete response, and 3 (17%) had a partial response, with an overall response rate of 22.3%. No apparent dose-response relationship was observed in our study. The mitoxantrone dosage recommended for phase II studies is 25 mg/m2 every 3-4 weeks. We conclude that high-dose mitoxantrone therapy for metastatic breast cancer was relatively well tolerated but was not associated with a higher response rate than that of standard dose mitoxantrone.

Adult↗
PubMed1999

Paclitaxel by 24-hour infusion with doxorubicin by 48-hour infusion as initial therapy for metastatic breast cancer: phase I results.

PURPOSE: We and others have demonstrated the antineoplastic efficacy of paclitaxel as a single agent in metastatic breast cancer. We performed this phase I trial to evaluate the combination of paclitaxel with doxorubicin. PATIENTS AND METHODS: Eligible patients had measurable or evaluable metastatic breast cancer for which this was the initial cytotoxic treatment. They may have received adjuvant chemotherapy with other drugs. The study had four parts. In part 1, the patients received paclitaxel by 24-hour infusion followed by doxorubicin by 48-hour infusion. The paclitaxel dose was to be escalated from a starting dose of 125 mg/m2, and the doxorubicin dose was to remain constant at 60 mg/m2 with treatment repeated every three weeks. The results of part 1 prompted part 2 which was a study of the reverse sequence. Part 3 was a formal study of pharmacology and has been reported (J Clin Oncol 14: 2713-21, 1996). In part 4, patients received doxorubicin 50 mg/m2 by bolus followed by paclitaxel 150 mg/m2 by 24-hour infusion for courses 1 and 2. In all subsequent courses doxorubicin was administered by 48-hour infusion. All patients in all four parts of the study had baseline cardiac scans. All patients received standard premedication for paclitaxel. RESULTS: Forty-eight patients were treated in all four parts of the study. In part 1 (10 patients), the maximum tolerated dose (MTD) was paclitaxel 125 mg/m2/24 hours followed by doxorubicin 48 mg/m2/48 hours as defined by dose-limiting mucositis and neutropenic fever which occurred at the starting dose. For part 2 (21 patients), the MTD was doxorubicin 60 mg/m2/48 hours followed by paclitaxel 160 mg/m2/24 hours. In part 4 (seven patients), the MTD was doxorubicin 50 mg/m2/bolus followed by paclitaxel 135 mg/m2/24 hours. In parts 2 and 4, the dose-limiting toxic effect was neutropenia. Of the entire cohort of 48 patients, seven (15%) had a complete response (one persists at five years without intervening therapy), 26 (54%) had a partial response for an objective response rate of 69% (95% confidence interval (95% CI): 54%-81%). The median follow-up of all living patients is 38+ months (range 20+ to 62+); the median response duration is seven months (range 2-33.7+); the median overall survival is 20.5 months (range 5-54+). The median time to progression is 9.6 months (range 1-33.7+ months). Two patients developed congestive heart failure, one at 24 months after her final dose of doxorubicin which amounted to a cumulative lifetime total doxorubicin dose of 870 mg/m2, one after a total of 660 mg/m2. In both, cardiac symptoms were controlled with medications. CONCLUSIONS: The combination of paclitaxel/24 hours with doxorubicin/48 hours is an effective antineoplastic treatment for metastatic breast cancer. However, the incidence of complete response, the median overall survival, and time to progression were not greater than for standard doxorubicin-based combinations. Additionally, a sequence-dependent interaction between paclitaxel and doxorubicin, given in the schedule described here, was defined. Other strategies and schedules should be evaluated to maximize the antineoplastic efficacy of these two potent agents.

Adult↗
PubMed1999

High calcium concentrations shift the mode of exocytosis to the kiss-and-run mechanism.

Exocytosis, the fusion of secretory vesicles with the plasma membrane to allow release of the contents of the vesicles into the extracellular environment, and endocytosis, the internalization of these vesicles to allow another round of secretion, are coupled. It is, however, uncertain whether exocytosis and endocytosis are tightly coupled, such that secretory vesicles fuse only transiently with the plasma membrane before being internalized (the 'kiss-and-run' mechanism), or whether endocytosis occurs by an independent process following complete incorporation of the secretory vesicle into the plasma membrane. Here we investigate the fate of single secretory vesicles after fusion with the plasma membrane by measuring capacitance changes and transmitter release in rat chromaffin cells using the cell-attached patch-amperometry technique. We show that raised concentrations of extracellular calcium ions shift the preferred mode of exocytosis to the kiss-and-run mechanism in a calcium-concentration-dependent manner. We propose that, during secretion of neurotransmitters at synapses, the mode of exocytosis is modulated by calcium to attain optimal conditions for coupled exocytosis and endocytosis according to synaptic activity.

Animals↗
PubMed1999

Prospective evaluation of paclitaxel versus combination chemotherapy with fluorouracil, doxorubicin, and cyclophosphamide as neoadjuvant therapy in patients with operable breast cancer.

PURPOSE: To compare prospectively the antitumor activity of single-agent paclitaxel to the three-drug combination of fluorouracil, doxorubicin, and cyclophosphamide (FAC) as neoadjuvant therapy in patients with operable breast cancer. PATIENTS AND METHODS: Patients with T1-3N0-1M0 disease were randomized to receive either paclitaxel (250 mg/m(2)) as 24-hour infusion or FAC in standard doses at every-3-week intervals. Each patient was treated with four cycles of preoperative chemotherapy. Clinical response and extent of residual disease in the breast and lymph nodes was assessed after four cycles of induction chemotherapy. RESULTS: A total of 174 patients were registered, and 87 were randomized to each arm of the study. Clinical response, ie, complete and partial responses, was similar in both arms of the study. Three patients in the FAC arm and one patient in the paclitaxel subgroup had progressive disease. The extent of residual disease by intent-to-treat analysis at the time of surgery was similar between the two arms of the study. CONCLUSION: The results of this prospective study demonstrated that single-agent paclitaxel as neoadjuvant therapy has significant antitumor activity, and this was clinically comparable to FAC. Similar fractions of patients had clinical complete and partial responses, and very few patients had no response to either therapy. The value of alternate non-cross-resistant therapies as used in this protocol on the clinical course of this disease would require longer follow-up.

Adult↗
PubMed1999

Phase II trial of liposome-encapsulated doxorubicin, cyclophosphamide, and fluorouracil as first-line therapy in patients with metastatic breast cancer.

PURPOSE: To determine the efficacy and safety profile, including the risk for cardiac toxicity, of liposome-encapsulated doxorubicin (TLC D-99), fluorouracil (5-FU), and cyclophosphamide as first-line chemotherapy in patients with metastatic breast cancer (MBC). PATIENTS AND METHODS: Forty-one women were registered in this phase II study. All patients had measurable disease and no previous chemotherapy for MBC. Treatment consisted of TLC D-99 60 mg/m2 and cyclophosphamide 500 mg/m2 on day 1 and 5-FU 500 mg/m2 on days 1 and 8 every 3 weeks. Serial cardiac monitoring, including endomyocardial biopsies, was performed. RESULTS: The overall response rate was 73% (95% confidence interval, 57% to 86%). The median duration of response was 11.2 months, the median time to treatment failure was 8.1 months, and the median overall survival duration was 19.4 months. The median number of cycles per patient was 10. The median cumulative dose of TLC D-99 was 528 mg/m2. Ten patients required hospitalization for febrile neutropenia. Nausea/vomiting, stomatitis, and fatigue higher than grade 2 occurred in 12%, 15%, and 41% of patients, respectively. Twenty-one patients reached a cumulative doxorubicin dose greater than 500 mg/m2. Three patients (7%) were withdrawn from the study due to protocol-defined cardiac toxicity, two because of a decrease in left ventricular ejection fraction to < or = 40%, and one because her endomyocardial biopsy result was grade 1.5. One patient had congestive heart failure that was probably nonanthracycline related. CONCLUSION: This chemotherapy regimen, including TLC D-99, was highly active against MBC and associated with low cardiac toxicity despite high cumulative doses of doxorubicin.

Adult↗