Docetaxel in patients with metastatic breast cancer: a phase II study of the National Cancer Institute of Canada-Clinical Trials Group

Docetaxel: a new active agent in the therapy of metastatic breast cancer

Breast cancer is the most common malignancy in women, accounting for about 18% of female cancers, and over half a million new cases are diagnosed worldwide each year. Its incidence increases with age and is currently rising. Although the increased availability of screening programs has allowed earlier detection and treatment of primary breast cancers, many patients relapse with metastases after apparently successful treatment of their primary tumor and over 15,000 women in the UK and about 50,000 in the USA die from advanced disease each year. The natural course of breast cancer is very variable even after the development of metastases, and depends on a variety of tumor characteristics and prognostic factors. This is reflected in the large number of treatments currently employed. However, despite this wide choice and considerable research over the years, treatment of metastatic breast cancer (MBC) prolongs average survival times only slightly. Current therapy is aimed at achieving a balance between producing maximal tumor shrinkage to produce the most effective possible palliation of symptoms, and minimizing adverse effects. Anticancer chemotherapy is the preferred option in patients who do not respond to hormones, those with hormone-independent tumors, those with aggressive breast cancer subtypes. A variety of anticancer chemotherapy regimens, using both single and combined agents, have been shown to be effective in achieving tumor regression in MBC. Anthracyclines (doxorubicin, epirubicin) are the most active of the established monotherapies, typically producing response rates of 50-60% during initial (first-line) treatment for metastatic disease, but being effective in fewer than 25% of patients requiring second-line therapy. The drawbacks of anthracyclines include dose-limiting cumulative cardiotoxicity and the development of resistant tumor clones after the use of anthracyclines for adjuvant or first-line therapy, especially if subsequent courses are required within a year. The success of these established chemotherapeutic agents depends greatly on the number and location of metastatic sites. Lymph node and soft tissue secondaries tend to respond well, while visceral metastases (especially in the liver) carry a particularly poor prognosis despite treatment. The outlook for patients with metastases involving more than two organ systems is also bleak. Although some patients can live for years with metastatic disease, the average survival time in patients with MBC is 18-24 months, while in those with liver metastases, life expectancy averages only 6 months. High-dose anticancer chemotherapy with granulocyte-colony stimulating factor (G-CSF) or autologous bone marrow transplantation has allowed the dose intensity of anthracyclines to be increased, and has improved the response rate to about 70% in selected patients with MBC. However, this approach has not been proven to improve survival, involves the risk of greater toxicity and drug-related mortality, and patients with reduced clearance of anthracyclines due to hepatic dysfunction from liver metastases may not be suitable candidates. A number of new anticancer agents have also recently been introduced in an attempt to improve on the performance and avoid the tolerability problems associated with anthracyclines. Among these, antitubulin agents (taxoids and vinorelbine) have shown highly promising activity in MBC. This paper reviews the preclinical, phase I and phase II data for one taxoid, docetaxel. Docetaxel (Taxotere) belongs to the taxoid class of cytotoxic agents, the development of which began more than 20 years ago. In 1971, paclitaxel (Taxol) was identified as the active compound of the crude extract of the bark of the Pacific Yew tree Taxus brevifolia. However, at that time the development of paclitaxel was hampered because of the limited source of the drug and difficulties with isolation, extraction and formulation. The second active taxoid, docetaxel, was isolated by Potier et al. in 1986. Docetaxel is prepared from a non-cytotoxic precursor, extracted from the needles of the European Yew tree Taxus baccata, that is condensed with a chemically-synthesized side-chain. As the docetaxel precursor is freely available because of the regenerating capacity of the needles the development of docetaxel has thus been rapid.

Randomized Pharmacokinetic and Pharmacodynamic Study of Docetaxel: Dosing Based on Body-Surface Area Compared With Individualized Dosing Based on Cytochrome P450 Activity Estimated Using a Urinary Metabolite of Exogenous Cortisol

Purpose

Docetaxel is metabolized by cytochrome P450 (CYP3A4) enzyme, and the area under the concentration-time curve (AUC) is correlated with neutropenia. We developed a novel method for estimating the interpatient variability of CYP3A4 activity by the urinary metabolite of exogenous cortisol (6-beta-hydroxycortisol [6-β-OHF]). This study was designed to assess whether the application of our method to individualized dosing could decrease pharmacokinetic (PK) and pharmacodynamic (PD) variability compared with body-surface area (BSA) –based dosing.

Patients and Methods

Fifty-nine patients with advanced non–small-cell lung cancer were randomly assigned to either the BSA-based arm or individualized arm. In the BSA-based arm, 60 mg/m2 of docetaxel was administered. In the individualized arm, individualized doses of docetaxel were calculated from the estimated clearance (estimated clearance = 31.177 + [7.655 × 10−4 × total 6-β-OHF] − [4.02 × alpha-1 acid glycoprotein] − [0.172 × AST] − [0.125 × age]) and the target AUC of 2.66 mg/L · h.

Results

In the individualized arm, individualized doses of docetaxel ranged from 37.4 to 76.4 mg/m2 (mean, 58.1 mg/m2). The mean AUC and standard deviation (SD) were 2.71 (range, 2.02 to 3.40 mg/L · h) and 0.40 mg/L · h in the BSA-based arm, and 2.64 (range, 2.15 to 3.07 mg/L · h) and 0.22 mg/L · h in the individualized arm, respectively. The SD of the AUC was significantly smaller in the individualized arm than in the BSA-based arm (P < .01). The percentage decrease in absolute neutrophil count (ANC) averaged 87.1% (range, 59.0 to 97.7%; SD, 8.7) in the BSA-based arm, and 87.4% (range, 78.0 to 97.2%; SD, 6.1) in the individualized arm, suggesting that the interpatient variability in percent decrease in ANC was slightly smaller in the individualized arm.

Conclusion

The individualized dosing method based on the total amount of urinary 6-β-OHF after cortisol administration can decrease PK variability of docetaxel.

Clinical trial update: National Cancer Institute of Canada

The Breast Cancer Site Group (BCSG) of the National Cancer Institute of Canada (NCIC) Clinical Trials Group (CTG) has conducted a wide variety of clinical trials focussing on large phase III trials of adjuvant chemotherapy, adjuvant hormonal therapy, and optimal delivery of adjuvant radiation therapy. The Group has also fostered, together with the NCIC CTG Investigational New Drug (IND) Program, a series of phase II and phase I/II studies which will be carried through if possible, into the phase III setting.

A Multicenter Phase II Study of Docetaxel 60 mg/m2 as First-Line Chemotherapy in Patients with Advanced or Recurrent Breast Cancer

PURPOSE

Docetaxel is an active agent as first-line chemotherapy in patients with advanced breast cancer at a dosage of 100 mg/m2. However, the efficacy of this agent as a first-line drug when used at a lower dosage is unclear. This study was performed to evaluate the clinical efficacy and safety of 60 mg/m2 docetaxel for the treatment of breast cancer.

PATIENTS AND METHODS

This study enrolled 23 patients with advanced and/or metastatic breast cancer, who had not been treated with an anthracycline or taxane previously. Treatment with docetaxel was continued in patients showing a response until there was evidence of disease progression or unacceptable toxicity.

RESULTS

Among 20 fully evaluated patients, the overall response rate was 50.0% and the median time to progression was 31 weeks. The most commonly observed adverse events were neutropenia (78.2%) and fatigue (60.9%). Fluid retention occurred in only 8.7% of the patients. Adverse events did not cause discontinuation of the treatment.

CONCLUSION

Docetaxel achieved good disease control with mild adverse events in first-line treatment at a dosage of 60 mg/m2.

Phase II Study of Feasibility of Dose-Dense FEC Followed by Alternating Weekly Taxanes in High-Risk, Four or More Node-Positive Breast Cancer

PURPOSE

To develop a potentially superior adjuvant chemotherapy regimen, we conducted a pilot study of dose-dense 5-fluorouracil, epirubicin, and cyclophosphamide (FEC) followed by weekly alternating taxanes. The primary objective was to determine the feasibility of the regimen; the secondary objective was to estimate the disease-free and overall survival.

EXPERIMENTAL DESIGN

Patients with >/=4 node-positive breast cancer were studied. Treatment consisted of FEC at 500/100/500 mg/m(2), respectively, x6 at two-week intervals with granulocyte colony-stimulating factor, followed by weekly paclitaxel (80 mg/m(2)) alternating with docetaxel (35 mg/m(2)) x18.

RESULTS

Between November 2001 and January 2003, 44 patients were enrolled. Median age was 46 years (range, 26-63 years), median number of positive nodes was 9 (range, 4-32), and median tumor size was 2.5 cm (range, 0.6-11.0 cm). Because of unexpected toxicities, the study was stopped when 17 (39%) had fully completed all of the planned treatment. Two of 17 (12%) developed grade 4 pericardial/grade 3 bilateral pleural effusions at treatment completion; both required pericardial window. The remaining patients were treated with taxanes using one of several standard dose and schedule combinations. Furthermore, 4 of 44 (9%) developed pneumonitis attributed to the FEC regimen. Hospital admissions were required for 12 of 44 (27%); 3 of 44 (7%) required blood transfusions. There were no treatment related deaths. Median disease-free and overall survival will not be estimatable because of early closure of study.

CONCLUSION

FEC x6 at 2-week intervals followed by 18 weeks of alternating taxanes is not feasible at the doses tested. Other strategies are needed to improve adjuvant systemic chemotherapy.

Safety and efficacy of weekly docetaxel in frail and/or elderly patients with metastatic breast cancer: a phase II study

This phase II study was designed to evaluate the safety and efficacy of weekly docetaxel (36 mg/m) for the treatment of metastatic breast cancer in 47 frail and/or elderly patients who were ineligible for the standard 3-weekly docetaxel (100 mg/m) regimen. Reasons for ineligibility to the latter were age > or = 70 years (10 patients), poor hematological reserves (15 patients), impaired liver function (eight patients), intolerance to previous taxanes administered 3-weekly without demonstrated resistance (five patients) or any combination of these reasons (nine patients). There was a median of two prior chemotherapy regimens and more than 60% had a WHO performance score at baseline of 2-3. A total of 408 weekly administrations were given over a period of 525 weeks (78% of the intended dose intensity) and the median cumulative dose of docetaxel per patient was 278 mg/m. The incidence of serious adverse events was low. Grade 3 neutropenia occurred in six patients and grade 4 in four patients. Of these 10 patients, eight had pre-existing hematological abnormalities and four developed neutropenic fever. Neurotoxicity was mild and grade 3 paraesthesia occurred in one patient. The overall objective response rate in 37 evaluable patients was 30% and responses were observed in all subgroups of patients. We conclude that weekly docetaxel (36 mg/m) is active, safe and well tolerated in heavily pre-treated frail/elderly patients with poor prognostic features, including low performance scores and multiple metastatic sites, who would not be eligible for treatment with the standard 3-weekly regimen.

Gemcitabine and Taxanes as a New Standard of Care in Breast Cancer

Advances in breast cancer continue to focus on the development of novel agents as well as the development of novel combinations, with the major therapeutic goal of treatment strategies revolving around improving response rates, delaying the time to disease progression, palliating symptoms, and improving quality of life. The taxanes are recognized as some of the most active single agents in breast cancer and demonstrate remarkable activity with manageable toxicity in combination with gemcitabine. Gemcitabine, a novel S-phase specific cytidine nucleoside analogue of deoxycytidine, has broad antitumor activity with significant monotherapy activity in breast cancer, with response rates ranging from 22% to 42% depending on the pretreatment characteristics of the patients. In general, gemcitabine s favorable single-agent activity and novel mechanism of action, in addition to its largely nonoverlapping toxicities, have facilitated its further development in combination with a variety of chemotherapy agents, including the taxanes. Several phase I and II trials have reported impressive activity for the gemcitabine/taxane doublet with the suggestion of clinical synergism between these 2 classes of agents. Given the remarkable and durable activity reported for this doublet, subsequent phase II trials have focused on optimizing doses and schedules. Unmistakably, these trial results are clear improvements over the single-agent activity of the taxanes in metastatic breast cancer, with the recently reported phase III trial comparing gemcitabine plus paclitaxel versus paclitaxel alone clearly reinforcing the superior outcomes demonstrated for the combination. Either as a single agent or in combination with the taxanes, gemcitabine remains a rational choice for the treatment of breast cancer.

Pharmacological effects of formulation vehicles : implications for cancer chemotherapy

The non-ionic surfactants Cremophor EL (CrEL; polyoxyethyleneglycerol triricinoleate 35) and polysorbate 80 (Tween) 80; polyoxyethylene-sorbitan-20-monooleate) are widely used as drug formulation vehicles, including for the taxane anticancer agents paclitaxel and docetaxel. A wealth of recent experimental data has indicated that both solubilisers are biologically and pharmacologically active compounds, and their use as drug formulation vehicles has been implicated in clinically important adverse effects, including acute hypersensitivity reactions and peripheral neuropathy.CrEL and Tween 80 have also been demonstrated to influence the disposition of solubilised drugs that are administered intravenously. The overall resulting effect is a highly increased systemic drug exposure and a simultaneously decreased clearance, leading to alteration in the pharmacodynamic characteristics of the solubilised drug. Kinetic experiments revealed that this effect is primarily caused by reduced cellular uptake of the drug from large spherical micellar-like structures with a highly hydrophobic interior, which act as the principal carrier of circulating drug. Within the central blood compartment, this results in a profound alteration of drug accumulation in erythrocytes, thereby reducing the free drug fraction available for cellular partitioning and influencing drug distribution as well as elimination routes. The existence of CrEL and Tween 80 in blood as large polar micelles has also raised additional complexities in the case of combination chemotherapy regimens with taxanes, such that the disposition of several coadministered drugs, including anthracyclines and epipodophyllotoxins, is significantly altered. In contrast to the enhancing effects of Tween 80, addition of CrEL to the formulation of oral drug preparations seems to result in significantly diminished drug uptake and reduced circulating concentrations. The drawbacks presented by the presence of CrEL or Tween 80 in drug formulations have instigated extensive research to develop alternative delivery forms. Currently, several strategies are in progress to develop Tween 80- and CrEL-free formulations of docetaxel and paclitaxel, which are based on pharmaceutical (e.g. albumin nanoparticles, emulsions and liposomes), chemical (e.g. polyglutamates, analogues and prodrugs), or biological (e.g. oral drug administration) strategies. These continued investigations should eventually lead to more rational and selective chemotherapeutic treatment.

Docetaxel plus epirubicin is a highly active, well-tolerated, first-line chemotherapy for metastatic breast cancer: results of a large, multicentre phase II study

PURPOSE

In this multicentre phase II study, the efficacy and safety profile of the combination of docetaxel and epirubicin as first-line chemotherapy for metastatic breast cancer (MBC) were evaluated.

METHODS

Epirubicin (75 mg/m(2)) and docetaxel (75 mg/m(2)) were given intravenously once every 3 weeks for six cycles to 133 patients with MBC.

RESULTS

The overall clinical response rate was 67% (complete and partial responses were 23% and 44%, respectively). The median time to progression was 10.8 months (95% CI 9.7-12.6) and the median overall survival was 19.5 months. Granulocyte colony-stimulating factor support was administered to 32% of patients and in 22% of cycles. Grade 3/4 neutropenia occurred in 35% of patients and febrile neutropenia in 19%. The most frequent grade 3/4 non-haematological toxicities (as percent of patients) were asthenia (6%), vomiting (5%) and nausea (5%). No patients developed congestive heart failure.

CONCLUSIONS

The combination of docetaxel and epirubicin was highly active as first-line treatment for MBC and showed a manageable toxicity profile.

A Phase II Study of Sequential Docetaxel Followed by Doxorubicin/Cyclophosphamide as First-Line Chemotherapy For Metastatic Breast Cancer

This phase II study assessed the activity and toxicity profile of the sequential administration of 3 cycles of docetaxel (100 mg/m2 every 3 weeks) followed by 3 cycles of AC (doxorubicin/cyclophosphamide; 60/600 mg/m2 every 3 weeks) as first-line chemotherapy in 30 patients with metastatic breast cancer. The response rate was 60% after docetaxel and 73% after AC. This reflected an increase in the rate of complete response (from 7% after docetaxel to 17% after AC). The median duration of response was 10.5 months, and the median time to progression was 12.6 months. The median survival time had not been reached after a median follow-up of 23.2 months. The sequential treatment was generally well tolerated, with grade 3/4 neutropenia found in 20% and 14% of patients treated with docetaxel and AC, respectively. No cumulative myelosuppression was detected. The incidence of grade 3/4 nonhematologic toxicities was low. The sequential administration of docetaxel followed by AC showed a high antitumor activity and a good safety profile. The hematologic toxicity found is markedly lower than that found using concomitant chemotherapy with the same drugs. Our results support the design of phase III trials that directly compare a sequential schedule with a concomitant schedule of docetaxel plus AC (or with doxorubicin only), focusing on the toxicity profile.

Combination of Docetaxel, Epirubicin and Vinorelbine Administered Every 2 Weeks as First-line Therapy in Patients with Metastatic Breast Cancer: A Dose-finding Study

AIMS

To assess efficacy and optimum combination dosage of intravenous docetaxel (T), epirubicin (E) and vinorelbine (N) administered every 2 weeks and without colony stimulating factor (CSF) support in patients with metastatic breast cancer (MBC).

PATIENTS AND METHOD

Patients (n = 5 1) with MBC were consecutively assigned to four different dose levels (DL) to receive (in mg/m2): Level I = T35 + E30 + N25; Level II = T30 + E30 + N25; Level III = T30 + E25 + N25; and Level IV = T25 + E25 + N25. Consecutive cycles were delayed if absolute neutrophil and/or platelet counts fell below 1.5 x 10(9) and 100 x 10(9) l(-1), respectively. Treatment at a given dose level was suspended if 33% or more of patients included in a given cohort had unacceptable toxicity.

RESULTS

The patients evaluable for toxicity (n = 48) received 448 cycles (median 9; range 1-23). There was neutropenia G 3-4 in 30 patients (63%) with fever in 3 (6%). The G 2-3 non-hematological toxicities were alopecia in 39 patients (81%), mucositis in 11 (23%), and nausea/vomiting in 8 (17%). There were no toxic deaths. Treatment delay or dose reduction after first cycle occurred in > or = 30% of patients treated in all DLs, except the fourth. Objective response was achieved in 29 of the 47 evaluable patients (58%; 95% CI: 50-66). The median duration of response, time-to-progression and overall survival were 13, 11 (range 8-14) and 20 (range 16-24) months, respectively.

CONCLUSION

The combination of docetaxel, epirubicin and vinorelbine without CSF support ought not to exceed 25 mg/m2 every 2 weeks. The efficacy is no greater than other existing regimens for first-line treatment of MBC.

Emerging role of taxanes in adjuvant and neoadjuvant therapy for breast cancer: the potential and the questions

Adjuvant chemotherapy has gained increasing prominence in the treatment of nonmetastatic breast cancer, producing gradual improvement in the survival of these patients. The taxanes offer great hope for adding to the progress in adjuvant treatment, but data have been conflicting. Early results of multi-center trials testing the sequential addition of paclitaxel to anthracycline-based adjuvant chemotherapy have perhaps been prematurely reported, but have already made a major impact on patterns of care for node-positive and even some node-negative patients. The early dramatic improvements in CALG 9344 are fading with time, however, and have not been confirmed by a second similar trial, NSABP B-28. Moreover, it cannot be stated with certainty whether the modest improvements observed by sequential addition of paclitaxel reflect the ability of this drug to kill anthracycline-resistant cancer cells or the increased total duration and amount of treatment. By contrast, the early results of the BCIRG 001 trial suggest that combining docetaxel with doxorubicin may significantly increase survival, but these early results should be viewed with caution and do not necessarily mean that docetaxel is superior to paclitaxel. The role of neoadjuvant chemotherapy for breast cancer has also expanded over the past 2 decades, from its initial use for inoperable locally advanced breast cancer (LABC) to its current use for patients with large operable tumors to make BCT feasible. The neoadjuvant approach also has an important role in clinical trials, where it will allow more rapid comparison of treatment regimens than can be accomplished in the adjuvant setting and provides an opportunity to analyze biologic markers as predictors of response. The value of this approach, however, will ultimately depend on a clear demonstration, not yet available, that a change in therapy that increases primary tumor response will also lead to improved long-term survival. The roles of docetaxel and paclitaxel in the neoadjuvant setting has been actively investigated over the past 5 to 10 years, and exciting results are beginning to emerge. Clearly, docetaxel has potent antitumor activity against breast cancer. Several preliminary results suggest that addition of docetaxel to an anthracycline-based regimen, particularly when added sequentially, as in NASBP B-27 and the Aberdeen trial, results in higher clinical and pathologic response rates. Whether this will translate into increased long-term survival, as suggested by the early results of the Aberdeen trial, remains to be seen. Whether sequential addition of docetaxel to doxorubicin is more or less effective than combining these drugs also has not been established. The results from M.D. Anderson suggesting that paclitaxel given on a weekly schedule was more effective than the same drug given every 3 weeks are particularly intriguing, and they may help to explain why the adjuvant studies with paclitaxel given every 3 weeks have not produced more dramatic results, whereas several studies with docetaxel (also given every 3 weeks) seem so positive. It may be that paclitaxel, with activity that is highly schedule-dependent and for which cell killing is more dependent on the duration of exposure, works best when given weekly, whereas the efficacy of docetaxel depends less on scheduling. If this is the case, then weekly paclitaxel may turn out to be equally effective as docetaxel appears to be even when given every 3 weeks. Alternatively, if docetaxel is simply a more active drug, then giving docetaxel weekly may be the most effective taxane regimen. Whether routine use of weekly chemotherapy administration in the adjuvant or neoadjuvant setting is practical or not is largely subjective, but at least it appears that the toxicity of this approach is acceptable. These issues are also being addressed in ongoing trials. Finally, taxanes have produced dramatic increases in response rates in the neoadjuvant setting, but, except for the Aberdeen trial, survival benefits have not yet been shown. If, however, the high pCR rates do translate into overall survival benefits that are greater than adding taxanes to postoperative adjuvant therapy, it might suggest that, unlike other drugs, taxanes are actually more effective before surgery than after, as predicted originally based on laboratory experiments. Clearly, much work remains to be done in this area of research on breast cancer therapy.

Weekly docetaxel as second-line therapy for patients with advanced breast cancer resistant to previous anthracycline treatment

This phase II trial evaluated the efficacy and toxicity of weekly docetaxel as treatment of advanced metastatic breast cancer patients resistant to prior anthracycline chemotherapy. After the first 18 patients, the initial dose (40 mg/m2, 30-min i.v. infusion for 6 consecutive weeks, followed by 2-week rest) was reduced to 36 mg/m2 in the remaining 17 patients due to the incidence of toxicity (28% grade 3-4 asthenia). Overall response rate was 34% (95% CI, 19-50): two complete (6%) and ten partial responses (28%) were found. The median duration of response was 6.8 months, the median time to disease progression was 8.4 months, and the median overall survival was 13.6 months (median follow-up of 11.4 months). Neutropenia was the only severe hematologic toxicity (17% of patients), whereas asthenia, nail, ocular and skin disorders were the most common nonhematologic toxicities. Only one death during further follow-up was related to toxicity (caused by pulmonary fibrosis). In conclusion, we found weekly docetaxel to be an active and safe chemotherapy regimen for patients with metastatic breast resistant to previous anthracyclines. This weekly regimen caused minimal myelosupression, while retaining significant activity against advanced breast cancer. Both factors provide attractive possibilities for the development of combination therapies incorporating weekly docetaxel. Nevertheless, the number of patients receiving either dose (40 and 36 mg/m2) which we studied is low and our results require confirmation on larger groups of patients.

Docetaxel and doxorubicin compared with doxorubicin and cyclophosphamide as first-line chemotherapy for metastatic breast cancer: results of a randomized, multicenter, phase III trial

PURPOSE

This randomized, multicenter, phase III study compared doxorubicin and docetaxel (AT) with doxorubicin and cyclophosphamide (AC) as first-line chemotherapy (CT) in metastatic breast cancer (MBC).

PATIENTS AND METHODS

Patients (n = 429) were randomly assigned to receive doxorubicin 50 mg/m(2) plus docetaxel 75 mg/m(2) (n = 214) or doxorubicin 60 mg/m(2) plus cyclophosphamide 600 mg/m(2) (n = 215) on day 1, every 3 weeks for up to eight cycles.

RESULTS

Time to progression (TTP; primary end point) and time to treatment failure (TTF) were significantly longer with AT than AC (median TTP, 37.3 v 31.9 weeks; log-rank P =.014; median TTF, 25.6 v 23.7 weeks; log-rank P =.048). The overall response rate (ORR) was significantly greater for patients taking AT (59%, with 10% complete response [CR], 49% partial response [PR]) than for those taking AC (47%, with 7% CR, 39% PR) (P =.009). The ORR was also higher with AT in patients with visceral involvement (58% v 41%; liver, 62% v 42%; lung, 58% v 35%), three or more organs involved (59% v 40%), or prior adjuvant CT (53% v 41%). Overall survival (OS) was comparable in both arms. Grade 3/4 neutropenia was frequent in both groups, although febrile neutropenia and infections were more frequent for patients taking AT (respectively, 33% v 10%, P <.001; 8% v 2%, P =.01). Severe nonhematologic toxicity was infrequent in both groups, including grade 3/4 cardiac events (AT, 3%; AC, 4%).

CONCLUSION

AT significantly improves TTP and ORR compared with AC in patients with MBC, but there is no difference in OS. AT represents a valid option for the treatment of MBC.

A randomized phase II study of alternating and sequential regimens of docetaxel and doxorubicin as first-line chemotherapy for metastatic breast cancer

BACKGROUND

This phase II study evaluated the feasibility and efficacy of alternating and sequential regimens of docetaxel and doxorubicin as first-line chemotherapy for metastatic breast cancer (MBC).

PATIENTS AND METHODS

Women with MBC requiring first-line chemotherapy for progressive disease (n = 106) were randomized and received 3-weekly monotherapy with docetaxel (T, 100 mg/m2, 1-h i.v. infusion) and doxorubicin (A, 75 mg/m2, 20-30-min i.v. infusion) either on a cycle-by-cycle alternating basis (ATATATAT, n = 51) or sequentially each for four cycles (TTTTAAAA, n = 55).

RESULTS

For both regimens, the median number of cycles administered was the maximum of eight. The alternating and sequential groups achieved similar objective tumor response rates (60% and 67%, respectively) and similar median duration of response (47 and 44 weeks, respectively). With a median follow-up of 31 months, median survival times were estimated at 20 and 26 months in the alternating and sequential groups, respectively. No unexpected toxicities were reported. Compared with alternating therapy, patients receiving sequential therapy were more likely to complete the planned eight chemotherapy cycles (69% versus 63%), and had a lower incidence of febrile neutropenia (2% versus 14%).

CONCLUSIONS

Alternating and sequential docetaxel-doxorubicin regimens are viable alternatives to simultaneous combination therapy in MBC, with sequential therapy achieving slightly higher response rates and improved tolerability compared with alternating therapy.

Weekly docetaxel in patients with pretreated metastatic breast cancer: a phase II trial

Docetaxel has consistently demonstrated its high activity as an antineoplastic agent in the treatment of metastatic breast cancer. However, 90% of patients receiving the recommended dose of 100 mg/m2 every 3 weeks will develop grade 3 or 4 neutropenia. Recent data suggest that the safety profile of a weekly docetaxel regimen compared favorably with the standard 3-week schedule. Thus, we initiated a phase II study to assess the efficacy and toxicity of weekly docetaxel in pretreated patients with metastatic breast cancer. Twenty patients with advanced, anthra-cycline-refractory breast cancer were included in this phase II trial. Docetaxel was administered at a starting dose of 40 mg/m2, repeated once a week for 3 consecutive weeks followed by a 1-week rest period (1 cycle). Patients were evaluated for tumor response every 8 weeks (after every other cycle). Therapy was continued for a maximum of six courses in patients showing tumor response or stable disease. Twenty patients received a total of 204 weekly infusions of docetaxel. The mean number of treatments was 10.2 (range 1-18). Eighteen patients were assessable for response. Five patients achieved a partial response and six patients showed either stable disease or a minor response. Seven patients had disease progression. The median survival was 7.8 months. Grade 3/4 leukopenia occurred in two patients. No other grade 3 or 4 hematologic toxicities were observed. The following grade 3/4 non-hematologic toxicities were seen: nausea/vomiting (one patient), infection (one patient), mucositis (two patients) and diarrhea (one patient). Three patients withdrew from the study due to dose-limiting toxicities (one due to severe neutropenia and two due to mucositis). We conclude that administration of docetaxel at a dose of 40 mg/m2 was effective and well tolerated even in heavily pretreated patients with metastatic breast cancer. This regimen is associated with only mild myelosuppression.

A randomized phase II study of sequential docetaxel and doxorubicin/cyclophosphamide in patients with metastatic breast cancer

BACKGROUND

Docetaxel has yielded promising response rates as a component of doxorubicin-based combination schedules in patients with metastatic breast cancer, including docetaxel/doxorubicin and docetaxel/doxorubicin/cyclophosphamide (AC). This randomized two-stage phase II study was conducted to evaluate sequential treatment with docetaxel and AC as first-line treatment in patients with recurrent or metastatic breast cancer previously untreated with chemotherapy for metastatic disease.

PATIENTS AND METHODS

Thirty-three patients were randomized to either docetaxel (100 mg/m(2)) on day 1 of a 21-day cycle for three cycles followed by AC (60/600 mg/m(2)) on day 1 of a 21-day cycle for three cycles (n = 17) or vice-versa (n = 16), without prophylactic granulocyte colony-stimulating factor support. In addition, we compared pre-treatment serum sErbB1 and sErbB2 protein concentrations with that of an age- and menopausal status-matched group of healthy women, and examined changes in serum sErbB1 and sErbB2 protein concentrations in these two treatment schedules. Data from each one of the two arms of the trial (docetaxel then AC, or AC and then docetaxel) were analyzed separately.

RESULTS

Enrollment was suspended after the first-stage of accrual, based on statistical design. Confirmed objective response rates after six cycles of treatment were 35% [95% confidence interval (CI) 14% to 62%] with docetaxel then AC and 38% (95% CI 15% to 65%) with AC then docetaxel. Dose reductions were frequent and mostly due to grade 4 neutropenia. Median survival time was 2.5 years in the docetaxel then AC group, and 1.1 years in the AC then docetaxel group. Serum sErbB1 concentrations were not significantly different between the study patients and healthy women, and did not change significantly after three and six cycles of treatment. In contrast, serum sErbB2 concentrations were significantly higher in the study patients compared with healthy women and tended to decrease after three and six cycles of treatment.

CONCLUSIONS

Response rates at the end of six cycles of treatment, which led to termination of accrual after the first stage using either the sequence of docetaxel first or docetaxel after AC chemotherapy, were lower than anticipated. However, median survival times and median progression-free survival times are similar to those reported in other studies. These data further suggest that additional studies to assess whether serum sErbB2 concentrations are useful predictors of responsiveness to chemotherapy are warranted.

Phase II study of oxaliplatin and fluorouracil in taxane- and anthracycline-pretreated breast cancer patients

PURPOSE

Phase II study evaluating efficacy and safety of combined oxaliplatin/fluorouracil (5-FU) in taxane-pretreated advanced and metastatic breast cancer (ABC) patients.

PATIENTS AND METHODS

Sixty-four taxane- and anthracycline-pretreated (within 6 months of study entry) women were treated with oxaliplatin 130 mg/m(2) (2-hour intravenous [IV] infusion), day 1, and 5-FU 1,000 mg/m(2)/d (continuous IV infusion) days 1 to 4, every 3 weeks.

RESULTS

Median patient age was 51 years (range, 34 to 71 years), with a median of two involved organs (range, one to six organs), and metastases in the liver (70%), bone (47%), and lung (34%). Patients had a median of two prior chemotherapy regimens (range, one to six regimens), and 78% had previous hormonal therapy, with clinical taxane and anthracycline resistance in 53% and 34%, respectively. A total of 367 cycles were administered, with a median of six cycles/patient (range, one to 15 cycles). Sixty patients were assessable for response (World Health Organization criteria): 17 partial response, 26 stable disease, and 17 disease progression, giving an overall response rate of 27% (95% confidence interval, 16.3% to 39.1%), and 26% and 36% in taxane- and anthracycline-resistant populations, respectively, all responders having metastatic liver disease. Median time to progression was 4.8 months, and median overall survival was 11.9 months. Four treatment-related serious adverse events occurred, seven patients withdrew because of treatment-related toxicity. Hematotoxicity was prevalent but rarely severe, with grade 3-4 neutropenia, leukopenia, and thrombocytopenia in 34%, 19%, and 16% of patients, respectively, and a single episode of febrile neutropenia. One third of patients developed grade 2-3 peripheral neuropathy (oxaliplatin-specific scale), with grade 3 in only 8%.

CONCLUSION

This oxaliplatin/5-FU combination is effective with an excellent safety profile in anthracycline/taxane-pretreated ABC patients, showing encouraging activity in patients with anthracycline/taxane-resistance or visceral disease.

Prevention and management of antineoplastic-induced hypersensitivity reactions

Acute hypersensitivity reactions (HSRs) are an unpredictable and potentially catastrophic complication of treatment with chemotherapeutic agents. Reactions may affect any organ system in the body and range widely in severity from mild pruritus to systemic anaphylaxis. Certain classes of chemotherapeutic agents, such as the taxanes, platinum compounds, asparaginases, and epipodophyllotoxins are commonly associated with HSRs. The clinical characteristics of these high risk agents with respect to HSRs are discussed in this review. Protocols to prevent or reduce the severity of these reactions have been developed, but despite these attempts, HSRs will still happen. Should a reaction occur, it is imperative that it be recognised quickly in order to minimise exposure to the inciting agent and implement appropriate therapeutic and supportive measures. When a patient becomes sensitised to a chemotherapeutic agent, avoidance of re-exposure is the mainstay of future prevention. For sensitised patients who have derived clinically meaningful benefit from a particular agent, however, continuation of treatment with the agent is desirable. Options may include attempting a trial of desensitisation or treatment with a related compound. Virtually all patients demonstrating HSRs to paclitaxel and docetaxel are able to successfully tolerate re-treatment following discontinuation and administration of diphenhydramine and hydrocortisone. Re-treatment has generally been less successful with platinum compounds. with recurrent HSRs occurring in up to 50% of patients following desensitisation protocols. Patients sensitised to asparaginase are often able to tolerate the alternative preparations, Erwinia carotovora asparaginase or polyethylene glycol-modified Escherichia coli asparaginase. There is very little experience with re-treatment following sensitisation to the epipodophyllotoxins. As re-treatment may have serious consequences, careful consideration of the risks and benefits of these strategies is imperative when deciding among these options.

Phase I study of vinorelbine and docetaxel with granulocyte colony-stimulating factor support in the treatment of metastatic breast cancer

PURPOSE

Vinorelbine and docetaxel are two active agents in the treatment of metastatic breast cancer. When given together, these drugs exhibit synergistic antitumor activity without significant pharmacokinetic interaction. The dose-limiting toxicities of this combination are neutropenic fever and mucositis. Adding granulocyte colony-stimulating factor (G-CSF) might lessen the toxicity and increase the maximum tolerated dose (MTD) of this combination. The aim of this study was to determine the MTD of vinorelbine and docetaxel given in combination with G-CSF.

PATIENTS AND METHODS

Between August 1997 and December 1998, 14 patients with metastatic breast cancer were enrolled in this study. All patients had received doxorubicin-based therapy, and 46% had received paclitaxel in the adjuvant or neoadjuvant setting. Patients were treated with vinorelbine at a starting dose of 20 mg/m2 intravenously over 10 min on days 1 and 5 and docetaxel at a starting dose of 85 mg/m2 intravenously over 1 hr on day 1, following the vinorelbine. Treatments were repeated every 21 days. Prophylactic G-CSF 5 mcg/kg was given subcutaneously on days 3-10. Toxicity was graded according to the National Cancer Institute's grading system.

RESULTS

A total of 65 cycles was administered at dose levels 0, -1, -2, and -3. The median absolute granulocyte count nadir for all courses was 200 mm(-3) (range, 0.1-7700 mm(-3)), and the median time to this nadir was 9 days (range, 7-30). The median platelet nadir was 163 (range, 27-401 k), and the median time to this nadir was 8 days (range, 7-30). The most common grade 3 nonhematologic toxicities for all courses were fatigue and myalgia, which occurred in 32 and 10 cycles, respectively. Neutropenic fever was encountered in 11 cycles. Three patients developed colitis-like pictures, two of whom died as a result. Consequently, the protocol was closed to accrual before a MTD was reached.

CONCLUSION

The combination of vinorelbine, docetaxel, and G-CSF in our hands has proven to be a toxic regimen, even when relatively low doses of vinorelbine and docetaxel are given. Meticulous observation of patients receiving this combination is warranted since the combination resulted in two deaths in this study.

Phase II study of weekly docetaxel in patients with metastatic breast cancer

BACKGROUND

This study was conducted to investigate the efficacy and toxicity of weekly docetaxel administration in patients with metastatic breast cancer.

PATIENTS AND METHODS

Thirty-seven women were treated with 1 h infusions of docetaxel at 40 mg/m2/week after pre-medication with 8 mg dexamethazone. Each cycle consisted of three consecutive weekly treatments followed by a 1 week rest. All patients were assessed for toxicity; five patients were not assessable for clinical response, time to progression (TTP) and overall survival (OS) because of early treatment failure, but they were included in intention-to-treat analysis.

RESULTS

Patients received a median of four cycles (range, 1-9), with a median dose intensity of 28 mg/m2/week (range 22-30) and a median relative dose intensity of 0.95 (range 0.73-1.0). No patients showed complete response, whereas 14 had partial response, which accounted for 38% of objective response rate [95% confidence interval (CI) 22% to 53%]. In addition, three patients (8%, 95% CI 0% to 17%) had stable disease over 6 months. Clinical responses were achieved at a median of three cycles (range 1-4 cycles). The median TTP and OS were 5 and 12 months, respectively. The weekly docetaxel regimen was generally well tolerated. About half of the patients experienced grade > or = 1 neutropenia; only 19% had grade 3/4 neutropenia, including one case of grade 4. No febrile neutropenia was observed and fluid retention syndrome was uncommon. Non-hematologic toxicity, however, such as asthenia/fatigue, nail damage, tearing or hearing disorders, was seen with successive treatment cycles.

CONCLUSIONS

Weekly docetaxel at 40 mg/m2/week is an active and feasible regimen for patients with metastatic breast cancer.

Monthly docetaxel and weekly gemcitabine in metastatic breast cancer: a phase II trial

BACKGROUND

Docetaxel and gemcitabine are active against breast cancer. The purpose of this phase II study was to evaluate the efficacy and safety of monthly docetaxel combined with weekly gemcitabine in patients with chemotherapy-pretreated metastatic breast cancer.

PATIENTS AND METHODS

Thirty-nine patients were enrolled, of whom thirty had received prior chemotherapy in the adjuvant setting, seven for metastatic disease, and two for both, including prior anthracycline in 33 patients. Treatment was gemcitabine 800 mg/m2 days 1, 8, 15 and docetaxel 100 mg/M2 on day 1, with cycles repeated every four weeks.

RESULTS

Response rate was 79% (95% confidence interval (CI): 63%-91%), with 2 complete and 29 partial responses. Twenty-five of the responders remained progression-free for more than six months. Median survival was 24.5 months. Delivered dose intensity of gemcitabine was lower than expected (63% of planned). The predominant hematologic toxicity was grade 4 neutropenia in 36 patients, complicated by fever in three patients. With the exception of asthenia, severe non-hematological toxicities were infrequent.

CONCLUSIONS

Monthly docetaxel, combined with weekly gemcitabine, has significant but manageable hematologic toxicity. Despite frequent dose adjustments, this doublet is very active in metastatic breast cancer, producing a high proportion of durable responses associated with favorable survival.

Phase II study of sequential administration of docetaxel followed by doxorubicin and cyclophosphamide as first-line chemotherapy in metastatic breast cancer

PURPOSE

To evaluate the feasibility and efficacy of a sequential administration of four cycles of docetaxel (100 mg/m(2) every 3 weeks) followed by four cycles of doxorubicin and cyclophosphamide (AC; 60/600 mg/m(2) every 3 weeks), with subsequent consolidation with docetaxel or AC, as first-line chemotherapy in patients with metastatic breast cancer (MBC).

PATIENTS AND METHODS

Forty-eight patients received 443 cycles of chemotherapy (median, 11 cycles/patient; range, 1 to 13 cycles). A total of 267 cycles of docetaxel (60.3%) and 176 of AC (39.7%) were given. Consolidation therapy was given to 33 patients (29 with docetaxel).

RESULTS

Grade 4 neutropenia was the most frequent toxicity (83% of patients). This was not cumulative and was rarely complicated by febrile neutropenia or severe infection. The nonhematologic safety profile was favorable: there were no grade 4 adverse events, and grade 3 episodes were infrequent. Docetaxel-specific toxicities were generally not severe. With a median cumulative doxorubicin dose of 397 mg/m(2) (range, 150 to 543 mg/m(2)), two incidences of unrelated congestive heart failure after further treatment with anthracyclines and two of asymptomatic left ventricular ejection fraction decrease were observed. Among the 42 assessable patients, five (12%) had complete and 25 (60%) had partial responses, for an overall response rate of 71% (95% confidence interval, 55% to 84%). Median duration of response was 53 weeks (range, 12 to 72 weeks), and median time to progression was 46 weeks (range, 3 of 72 weeks). With a median follow-up of 40.4 months, median survival was 32 months (range, 2 to 55 months).

CONCLUSION

This docetaxel-based sequential schedule is safe and effective in first-line therapy for MBC, without incurring cumulative toxicity, and provides a feasible chemotherapeutic option in this clinical setting.

Noncardiogenic pulmonary edema: an unusual and serious complication of anticancer therapy

Noncardiogenic pulmonary edema (NCPE) is a rare and less well-recognizable pulmonotoxic syndrome of anticancer therapy than pneumonitis/fibrosis. NCPE is a clinical syndrome characterized by simultaneous presence of severe hypoxemia, bilateral alveolar infiltrates on chest radiograph, and no evidence of left atrial hypertension/congestive heart failure. The diagnosis of drug-related NCPE relies upon documented exclusion of any infectious, metabolic, or cancer-related causes. The time proximity to therapy with drugs that are known to precipitate NCPE, any preceding episodes of flu-like symptoms during previous chemotherapy courses and possible response to corticosteroids may further support such a diagnosis. Cancer therapeutic agents clearly associated with NCPE are cytarabine, gemcitabine, and interleukin-2, as well as all-trans retinoic acid in acute promyelocytic leukemia patients, while a few other compounds have rarely or occasionally been implicated. The pathophysiology of lung injury in drug-induced NCPE remains unclear. There are indications suggesting that both a direct cytotoxic insult to the lung epithelial cells and induction of a cytokine-triggered inflammatory response may be involved in its pathogenesis. By distinction to drug-induced pulmonary pneumonitis that may lead to permanent pulmonary fibrosis, NCPE if not fatal, can be reversed upon prompt recognition, following immediate discontinuation of the offensive drug and start of intensive supportive treatment and intravenous corticosteroids.

Phase I dose-finding and pharmacokinetic study of docetaxel and vinorelbine as first-line chemotherapy for metastatic breast cancer

BACKGROUND AND PURPOSE

Anthracycline-containing regimens are widely used in advanced breast cancer. However, there is a need for new, non-anthracycline regimens that are active in patients for whom anthracyclines are contraindicated. The aim of this study was to determine the maximum tolerated dose (MTD), the dose-limiting toxicities (DLTs) and recommended doses of docetaxel and vinorelbine as first-line chemotherapy in patients with metastatic breast cancer. The pharmacokinetics of both drugs was also evaluated.

PATIENTS AND METHODS

Thirty-four women with first-line metastatic breast cancer were treated with docetaxel, 60-100 mg/m2 (day 1), and vinorelbine, 20-22.5 mg/m2 (days 1 and 5), repeated every three weeks and administered on an outpatient basis.

RESULTS

Two MTDs were determined: MTD1 was defined at the dose level using docetaxel 75 mg/m2, and vinorelbine 22.5 mg/m2 DLT being a grade 3 stomatitis that was more related to the dose of vinorelbine than that of docetaxel. Therefore, the study continued with a fixed dose of vinorelbine, 20 mg/m2, and docetaxel 85-100 mg/m2. MTD2 was defined at the dose level combining docetaxel, 100 mg/m2, and vinorelbine, 20 mg/m2; DLTs were grade 3 stomatitis and severe asthenia. Fluid retention was observed in 41% of patients but was never severe or a reason for patient discontinuation. In comparison with historical experience, Daflon 500 did not seem to increase the efficacy of the three-day corticosteroid premedication by further reducing the incidence or severity of fluid retention. No significant neurotoxicity was observed and no patient discontinued the study due to this site effect. Activity was observed at all dose levels and at all metastatic sites, with an overall response rate of 71% (95% CI: 52.0%-85.8%). The median time to progression was 31.4 weeks (95% CI: 12-48 weeks) and median survival was 15.6 months (95% CI: 2.6-26.6 months). The pharmacokinetics of docetaxel and vinorelbine were not modified between day 1 and day 3 when the two drugs were combined with the day 1 administration schedule used in this study.

CONCLUSION

The recommended doses for phase II studies are docetaxel, 75 mg/m2 (day 1), plus vinorelbine, 20 mg/m2 (days 1 and 5), repeated every three weeks. At these doses, the combination was found to be active and well tolerated.

Doxorubicin and paclitaxel versus fluorouracil, doxorubicin, and cyclophosphamide as first-line therapy for women with metastatic breast cancer: final results of a randomized phase III multicenter trial

PURPOSE

This phase III trial compared the efficacy and safety of doxorubicin and paclitaxel (AT) to 5-fluorouracil, doxorubicin, and cyclophosphamide (FAC) as first-line therapy for women with metastatic breast cancer.

PATIENTS AND METHODS

A total of 267 women with metastatic breast cancer were randomized to receive either AT (doxorubicin 50 mg/m(2) followed 24 hours later by paclitaxel 220 mg/m(2)) or FAC (5-fluorouracil 500 mg/m(2), doxorubicin 50 mg/m(2), cyclophosphamide 500 mg/m(2)), each administered every 3 weeks for up to eight cycles. Patients had to have measurable disease and an Eastern Cooperative Oncology Group performance status of 0 to 2. Only one prior non-anthracycline, nontaxane-containing adjuvant chemotherapy regimen was allowed.

RESULTS

Overall response rates for patients randomized to AT and FAC were 68% and 55%, respectively (P =.032). Median time to progression and overall survival were significantly longer for AT compared with FAC (time to progression 8.3 months v 6.2 months [P =.034]; overall survival 23.3 months v 18.3 months [P =.013]). Therapy was generally well-tolerated (median of eight cycles delivered in each arm). Grade 3 or 4 neutropenia was more common with AT than with FAC (89% v 65%; P <.001); however, the incidence of fever and infection was low. Grade 3 or 4 arthralgia and myalgia, peripheral neuropathy, and diarrhea were more common with AT, whereas nausea and vomiting were more common with FAC. The incidence of cardiotoxicity was low in both arms.

CONCLUSION

AT conferred a significant advantage in response rate, time to progression, and overall survival compared with FAC. Treatment was well-tolerated with no unexpected toxicities.

New horizons in treating metastatic disease

The management of metastatic breast cancer is changing as a consequence of extraordinary discoveries in cancer research and the development of more advanced diagnostic technologies. Although traditional chemotherapeutics such as anthracyclines and taxanes still represent the mainstay of treatment for this disease, new drugs are demonstrating significant clinical activity and sometimes a better toxicity profile. Furthermore, the successful introduction into clinical practice of biological agents, in particular the monoclonal antibody trastuzumab, offers a key to the future of managing metastatic breast cancer. A therapeutic approach based on modifications of a specific molecular target (e.g., gene therapy, vaccines, and antiangiogenesis) alone or combined with the traditional chemotherapeutic drugs is expected to be used more commonly and will, we hope, bring significant improvement in the clinical response and quality of care of our patients.

Front-line treatment of advanced breast cancer with docetaxel and epirubicin: a multicenter phase II study

PURPOSE

In a previous phase I trial we evaluated the toxicity and determined the maximum tolerated doses of the docetaxel (D)-epirubicin (Epi) combination. We conducted a multicenter phase II study to evaluate the efficacy and tolerability of this regimen as front-line treatment in women with advanced breast cancer (ABC).

PATIENTS AND METHODS

Fifty-four women with ABC stage IIIB (4 patients) or IV (50 patients) received front-line treatment with Epi 70 mg/m2 on day 1 and D 90 mg/m2 on day 2. The median age was 55 years, performance status (WHO) was 0-1 in 49 patients and visceral disease was present in 45 (83%).

RESULTS

All patients were evaluable for toxicity and 50 for response. In an intent-to-treat analysis complete remission was observed in 5(9%) patients, partial remission in 31 (57%) (overall response rate 66%, 95% confidence interval: 54% 79%), stable disease in 9 (17%) and disease progression in 9 (17%). After a median follow-up of 11.5 months, the median duration of responses was 8 months, the median time to disease progression 11.5 months and the median survival has not yet been reached. The probability of one-year survival was 65%. Three hundred six cycles of treatment were administered (median 6 cycles per patient). Grade 3 and 4 neutropenia was observed in 8 (15%) and 31 (57%) patients, respectively, and febrile neutropenia in 19 (35%). Prophylactic rh-G-CSF was used in 45 (83%) patients or 226 (74%) cycles. Other hematologic or non-hematologic toxicities were usually mild. In five (9%) patients the left ventricular ejection fraction (LVEF) was decreased by more than 10% with the treatment. Two patients died during the treatment of respiratory failure without associated neutropenia.

CONCLUSIONS

The combination of docetaxel epirubicin is an effective and well tolerated front-line treatment in patients with ABC.

Single-agent docetaxel in metastatic breast cancer patients pre-treated with anthracyclines and paclitaxel: partial cross-resistance between paclitaxel and docetaxel

The purpose of this study was a retrospective analysis of docetaxel in a cohort of anthracyclines and paclitaxel pretreated patients with metastatic breast cancer. From July 1998 to June 1999, 24 consecutive patients were included for this study. The regimen consisted of docetaxel 75 mg/m2 in combination with a 3-day schedule of dexamethasone every 3 weeks until disease progression or unacceptable toxicity. The median age of patients was 53 (ranged 32-67) years with a median performance status of 2. Twenty of the 24 patients (84%) had measurable disease. The median number of organs involved was 2 (range 1-4). A total of 146 cycles chemotherapy were given with a mean of 6. There was a 25% (six of 24) overall response rate including one complete response, 37.5% stable disease and 37.5% progressive disease. The major toxicity included grade 3-4 leukopenia (41.7%) and eight episodes of infection. No treatment-related death was observed. The responders included patients refractory to or resistant to prior paclitaxel treatment. The median survival and median time to disease progression was 12 and 9 months, respectively. We conclude that docetaxel has a modest activity in breast cancer patients pre-treated with anthracyclines and paclitaxel, indicating a partial cross-resistance between paclitaxel and docetaxel.

Radiologist review versus group peer review of claimed responses in a phase II study on high-dose ifosfamide in advanced soft tissue sarcomas of the adult: a study of the EORTC Soft Tissue and Bone Sarcoma Group

The Soft Tissue and Bone Sarcoma Group (STBSG) of the EORTC ran a phase II study to assess the therapeutic activity of high-dose ifosfamide in patients with advanced soft tissue sarcomas by means of response rate (RR). Investigators claiming a response submitted the relevant chest radiographs (CXR) or scans to two other members of the STBSG for peer review. The reviewers completed a questionnaire indicating overall response or reasons for rejecting the claimed responses. An independent radiologist also reviewed the cases and he was blinded to the results of the peer review until the study was concluded. Twenty-two patients were reviewed by the radiologist and peer review, and the completed questionnaires were retrospectively reviewed. Two differences were noted, one partial responder (PR) was regarded as stable disease by the radiologist and one PR by peer review was determined a complete response by the radiologist. The radiologist found subsequent evidence of progressive disease in three patients who initially showed a PR, whilst the review group noted only one. This study suggests peer review in this tumor type is a satisfactory method of achieving an accurate, objective RR.

Correlation between docetaxel clearance and estimated cytochrome P450 activity by urinary metabolite of exogenous cortisol

PURPOSE

There is no simple and practical method for the estimation of the interpatient variability of cytochrome P450 (CYP3A4) enzyme activity. Cortisol is metabolized by this enzyme and excreted as 6-beta-hydroxycortisol (6beta-OHF) and free-cortisol (FC) in urine, and docetaxel is also metabolized by hepatic CYP3A4 enzyme. We developed a new method for the estimation of CYP3A4 activity by measuring urinary cortisol metabolite after administration of exogenous cortisol. This study was aimed at assessing the predictability of the individual activity of CYP3A4 estimated by this method.

PATIENTS AND METHODS

Thirty patients with advanced non-small-cell lung cancer were entered onto this study. Hydrocortisone 300 mg was administered intravenously, and urinary 6beta-OHF and FC were measured. More than 2 days later, 60 mg/m(2) of docetaxel was administered intravenously with pharmacokinetic sampling. The correlation between docetaxel pharmacokinetics and estimated interpatient variability of CYP3A4 activity with the application of our method was assessed.

RESULTS

After cortisol administration, the total amount of 24-hour urinary 6beta-OHF (T6beta-OHF) increased about 60-fold compared with pretreatment levels, averaging 12,273 +/- 4,076 microg/d (mean +/- SD). Docetaxel clearance (CL) and area under the concentration-time curve averaged 24.5 +/- 6.4 L/h/m(2) and 2.66 +/- 0.91 mg/L 8729. h, respectively. An excellent correlation between docetaxel CL and T6beta-OHF was observed (r =.867). In multivariate analysis, T6beta-OHF (P <.001), alpha-1-acid glycoprotein (P <.004), AST (P =.007), and age (P =. 022) significantly correlated with docetaxel CL.

CONCLUSION

The interpatient variability of CYP3A4 activity and docetaxel CL could be predicted by measuring T6beta-OHF after cortisol administration.

Toxicity and activity of docetaxel in anthracycline-pretreated breast cancer patients: a phase II study

Docetaxel has proven effective in advanced breast cancer. Myelosuppression and cumulative fluid retention syndrome are troublesome, potentially avoidable toxicities. In this consecutive cohort study, docetaxel (100 mg/m2 by 1 hour i.v. infusion, q3 weeks) activity and toxicity was explored in 56 anthracycline-pretreated patients (eligible: 55: median age: 51 years [range: 28-68 years]; median performance status: 0 [range: 0-3]) with metastatic breast cancer, using two different granulocyte colony-stimulating factor and steroid pre- and postmedication schedules. Twenty-nine patients (group A) received a 5-day oral prednisone premedication, and 26 (group B) received 4-day low-dose i.m. dexamethasone; group B patients also received prophylactic granulocyte colony-stimulating factor. All patients were evaluable for toxicity and 53 for response. Prophylactic granulocyte colony-stimulating factor significantly lowered the incidence of grade III-IV neutropenia and neutropenic fever (p = 0.0001 and 0.01, respectively). The incidence of moderate-severe fluid retention syndrome was lower in patients receiving i.m. dexamethasone (p = 0.08). Overall response rate was 53% (4 complete responses/24 partial responses, 95% confidence interval 39.4-66.2%); 32% have stable disease and 15% progressive disease. In 21 anthracycline-refractory/resistant patients, as well as in 10 paclitaxel-pretreated patients, the overall response rate was 50%. Docetaxel is highly active in anthracycline- and paclitaxel-pretreated metastatic breast cancer, with manageable toxicity. Optimal use of both granulocyte colony-stimulating factor support and steroid premedication deserves further investigation.

Docetaxel in 253 previously treated patients with progressive locally advanced or metastatic breast cancer: results of a compassionate use program in The Netherlands

The aims of this study were to evaluate the efficacy and safety of docetaxel (Taxotere) in patients with progressive locally advanced or metastatic breast cancer, previously treated with at least one chemotherapy regimen, and the effect of the number of previous chemotherapy lines on response rate, progression-free survival and overall survival. Two-hundred and fifty-three patients from 10 hospitals in The Netherlands received docetaxel as part of a compassionate use program. The majority had received prior anthracycline-containing chemotherapy (84.2%). The recommended starting dose was 100 mg/m2 i.v. every 3 weeks. All patients received corticosteroid premedication. Two-hundred and thirty patients were evaluable for response. The overall response rates (ORR) to docetaxel when used as second-, third- or fourth-line treatment were, respectively, 40.2, 26.0 and 34.6% (p value 0.30). The median progression-free survival for this population was 4.9 months and the median overall survival of the whole group was 8.5 months, and both were not related to the number of previous chemotherapy regimens (p value, respectively, 0.71 and 0.16). The toxicity of docetaxel was manageable and neutropenia was the most frequently noted toxicity. This study confirms that docetaxel is an active cytotoxic agent in pretreated patients with progressive locally advanced or metastatic breast cancer and is still active when used as third- or fourth-line treatment.

Monotherapy with docetaxel in second- or third-line treatment of anthracycline-resistant metastatic breast cancer

Nineteen breast cancer patients pretreated with one or two anthracycline-containing regimens for visceral metastases received i.v. docetaxel 100 mg/m2 on day 1, q 21d. Docetaxel was administered as second-line therapy in 11 patients, whereas eight patients received docetaxel in a third-line setting. In the second-line setting, complete response (CR) was achieved in two (18%), partial response (PR) in four (36%) and stable disease (SD) in three (27%) patients resulting in a response rate (RR) of 54%. In the third-line setting three (38%) patients experienced PR (RR 38%) and two (25%) SD. In the second-line setting, median time to progression was 6.5+/-3.9 months (range 2.1-15.8) versus 4.7+/-5.5 months (range 0.6-15.9) in the third-line setting. Median overall survival was 9.6+/-8.0 months (range 2.7-25.8) versus 11.2-6.1 months (range 4.8-18.7). Overall, no patient experienced treatment-limiting toxicities. We conclude that docetaxel induced responses in 48% of anthracycline-resistant patients enrolled into the present study. The safety profile of docetaxel was manageable and tolerable. Docetaxel represented efficacious treatment in patients with metastatic breast cancer progressing despite previous anthracycline-containing chemotherapy.

Docetaxel administered on a weekly basis for metastatic breast cancer

PURPOSE

To evaluate the safety and efficacy of weekly docetaxel in women with metastatic breast cancer.

PATIENTS AND METHODS

Twenty-nine women were enrolled onto a study of weekly docetaxel given at 40 mg/m(2)/wk. Each cycle consisted of 6 weeks of therapy followed by a 2-week treatment break, repeated until disease progression or removal from study for toxicity or patient preference. Fifty-two percent of patients had been previously treated with adjuvant chemotherapy; 21% had received prior chemotherapy for metastatic breast cancer, and 31% had previously received anthracyclines. All patients were assessable for toxicity; two patients were not assessable for response but are included in an intent-to-treat analysis.

RESULTS

Patients received a median of 18 infusions, with a median cumulative docetaxel dose of 720 mg/m(2). There were no complete responses. Twelve patients had partial responses (overall response rate, 41%; 95% confidence interval, 24% to 61%), all occurring within the first two cycles. Similar response rates were observed among subgroups of patients previously treated either with any prior chemotherapy or with anthracyclines. An additional 17% of patients had stable disease for at least 6 months. The regimen was generally well tolerated. There was no grade 4 toxicity. Only 28% of patients had any grade 3 toxicity, most commonly neutropenia and fatigue. Acute toxicity, including myelosuppression, was mild. Fatigue, fluid retention, and eye tearing/conjunctivitis became more common with repetitive dosing, although these side effects rarely exceeded grade 2. Dose reductions were made for eight of 29 patients, most often because of fatigue (n = 5).

CONCLUSION

Weekly docetaxel is active in treating patients with metastatic breast cancer, with a side effect profile that differs from every-3-weeks therapy.

Factors predicting for efficacy and safety of docetaxel in a compassionate-use cohort of 825 heavily pretreated advanced breast cancer patients

PURPOSE

To identify predictive factors for efficacy and safety in advanced breast cancer (ABC) patients treated in the French compassionate-use docetaxel program.

PATIENTS AND METHODS

A total of 825 ABC patients treated with docetaxel (100 mg/m(2) every 3 weeks) were source-reviewed and analyzed for prognostic factors associated with overall response rate (ORR), time to treatment failure (TTF), overall survival (OS), febrile neutropenia, mucositis, and severe fluid retention syndrome by univariate and multivariate analysis.

RESULTS

The ORR was 22.9% (95% confidence interval, 20.2% to 26.2%). The median TTF and OS were 4.0 and 9.8 months, respectively. By multivariate analysis, secondary anthracycline-resistant disease was significantly associated (P <. 05) with lower ORR and shorter TTF and OS, whereas anthracycline-refractory disease was associated with shorter OS. Poor performance status was associated with lower ORR, shorter TTF, and shorter OS. Liver dysfunction (transaminase levels > 1.5 times the upper limit of normal [ULN] and alkaline phosphatase [AP] level > three times ULN) and time since first relapse less than 24 months were associated with shorter TTF and OS. Other significant correlations included the following: elevated CA 15-3 serum level with lower ORR; more than two involved sites, and minor transaminase and AP level abnormalities with shorter OS; and no previous chemotherapy for ABC with shorter TTF. According to multivariate analysis, ORR, TTF, and OS were not decreased in patients with liver metastases but without liver dysfunction.

CONCLUSION

Docetaxel activity was maintained in heavily pretreated ABC patients and in those with liver metastasis; docetaxel must be used cautiously, however, in patients with liver dysfunction in whom high morbidity risk necessitates strict adherence to dose-adaptation guidelines.

Chemotherapy of breast cancer: are the taxanes going to change the natural history of breast cancer?

Among the novel chemotherapeutic drugs introduced in the last decade, taxanes have emerged as the most powerful compounds and results available to date suggest that they will be remembered in the future as the breast cancer chemotherapy of the 1990s. The two taxanes (paclitaxel, Taxol, Bristol-Myers Squibb and docetaxel, Taxotere, Rhône-Poulenc Rorer) share some characteristics, but are also significantly different both in preclinical profile and, most importantly, in clinical characteristics. The main clinical differences are related to their different efficacy-toxicity ratio in relation to dose and schedule; the differing integrability of paclitaxel and docetaxel in anthracycline-taxane containing regimens, secondary to major differences in pharmacokinetic interactions between each taxane and the anthracyclines, and; the potential differences in level of synergism between each taxane and herceptin (HeR2Neu antibody/trastuzumab, Genentech/Roche). In clinical practice, the taxanes are now standard therapy in metastatic breast cancer after prior chemotherapy, in particular anthracyclines, has failed. Their role in combination with anthracyclines in first-line therapy of advanced breast cancer is emerging and sheds new light on the potential role of taxanes in the adjuvant setting. However, the impact of taxanes on the natural history of breast cancer is yet to be defined, despite the trend of results suggesting that these agents have the potential for significant improvements in advanced and, most importantly, adjuvant therapy of breast cancer. The results of all completed or ongoing Phase III trials in first-line metastatic and the adjuvant setting will help determine if taxanes will further improve the outcome of breast cancer or not.

Docetaxel-cisplatin combination (DC) chemotherapy in patients with anthracycline-resistant advanced breast cancer

PURPOSE

The safety and efficacy of a docetaxel-cisplatin combination (DC) were evaluated in 41 patients pretreated for advanced breast cancer (ABC).

PATIENTS AND METHODS

The first 2 patients received 85 mg/m2 docetaxel followed, 6 hours later, by 80 mg/m2 cisplatin repeated every 3 weeks; the other 39 received the same regimen, with 75 mg/m2 docetaxel. Appropriate dose reductions but no growth factor administration were planned. Treatment was continued until disease progression, excessive toxicity or patient refusal.

RESULTS

A total of 223 chemotherapy courses were administered, with a median of 6 cycles per patient (range 1-8). All 41 patients were assessed for toxicity using NCI-CTC. Severe neutropenia was experienced by 38 patients (93%) (11 at grade 3, 27 at grade 4, 10 with febrile neutropenia). There was one death due to neutropenic septic shock. Grade 3 thrombocytopenia occurred in three patients (7%). Five patients (12%) had grade 2 neurosensory toxicity, two (5%) experiencing partial hearing loss. Grade 3 fluid retention occurred in three patients (7%). Of 38 anthracycline-resistant patients, 33 were evaluable for response. Two had a complete response (CR) and ten a partial response (PR), giving an objective response rate of 36%, (95% CI: 20%-55%). Stable disease (SD) was observed in 14 patients (42%), 7 (21%) had progressive disease (PD). Among the three non-resistant patients, two PRs and one SD were observed. Median duration of response was 29 weeks (range 18-70), median time to progression 21 weeks (4-70), and median overall survival 50 weeks (4-104+).

CONCLUSIONS

This DC regimen is active, with an acceptable safety profile in anthracycline-resistant ABC patients. Its place as a second-line treatment alternative to docetaxel alone or to other second-line combination regimens remains to be determined.

Docetaxel in combination with epirubicin in metastatic breast cancer: pharmacokinetic interactions

Epirubicin (75 mg/m2) and docetaxel (75 mg/m2) were administered to 16 patients affected by metastatic breast cancer following two different schedules: (1) docetaxel as infusion administered 1 h after epirubicin administration (schedule A); and (2) docetaxel as infusion immediately (10 min) after the end of epirubicin i.v. bolus administration (schedule B). Experimental non-compartmental analyses such as AUC and Css, were affected very little by the drug combination, irrespective of whether the administration of docetaxel was immediately after the epirubicin bolus (10 min) or delayed (1 h). However, serum levels showed evidence of transient drug interaction: in schedule A, docetaxel infusion was associated with a transient increase of plasma epirubicin in correspondence with Cssmax of docetaxel. Bi-compartmental analysis showed a significant difference in epirubicin clearance between protocols A and B. It is suggested that polysorbate 80, used in minimal amounts to formulate docetaxel, may interfere with epirubicin plasma level.

Efficacy and safety of docetaxel (Taxotere) in heavily pretreated advanced breast cancer patients: the French compassionate use programme experience

The aim of this investigation was to assess retrospectively docetaxel safety and efficacy in advanced breast cancer patients in a French compassionate use programme. Patients had received > 1 prior chemotherapy regimen for advanced disease, were either anthracycline-resistant (that is progressed within 6 months after anthracycline-based chemotherapy) or had received the maximum cumulative dose. The recommended docetaxel dose was 100 mg/m2/cycle (75 mg/m2 in case of liver function impairment: transaminases > 1.5 x upper limit of normal (ULN), alkaline phosphatases > 3 x ULN). Between August 1993 and December 1995, 889 patients were treated in 67 French centres, of whom 870 were evaluable for safety and 825 were evaluable for patient and treatment characteristics and efficacy. 20.5% (of the 825 patients evaluable for baseline characteristics) had poor performance status (PS > or = 2), 49.3% liver metastasis and 9.6% biological liver dysfunction. 98.4% had been previously treated by anthracyclines, 50.8% had resistant disease and 37.1% had received > 2 prior palliative chemotherapy lines. The most frequent severe toxicity, febrile neutropenia (reported in 223/870 (25.6%) patients evaluable for safety), caused 10 deaths, 6 of these being patients with severe liver impairment before inclusion. Fluid retention syndrome and other common non-haematological toxicities were well tolerated. 3.1% (28/889) of all patients and 11.4% of those with liver dysfunction, died from treatment-related causes. The overall response rate in 825 assessable patients was 22.9% (95% confidence interval (CI): 20.2-26.2%). Median time to treatment failure was 4 months (95% CI: 3.6-4.3) and median survival was 9.8 months (95% CI: 8.8-10.7). This report on the largest series of unselected advanced breast cancer patients treated with docetaxel, supports previous phase II studies, confirming docetaxel's utility in patients relapsing after failing anthracycline-containing palliative chemotherapy.

Weekly docetaxel in minimally pretreated cancer patients: a dose-escalation study focused on feasibility and cumulative toxicity of long-term administration

BACKGROUND

Docetaxel is an agent with impressive clinical activity but a rather poor profile of toxicity when given every three weeks. Therefore, optimisation of its clinical use is highly warranted. This is a dose-escalation study of weekly docetaxel particularly focused on the feasibility of long-term administration and characterisation of cumulative toxicity.

PATIENTS AND METHODS

Twenty-six patients (11 female/15 male, median age 56, range 23-73) were treated over the range of 25-50 mg/m2/week. Dose-limiting toxicity for this schedule was defined as any grade > 2 antiproliferative toxic effect resulting in a > 2-week delay for re-administration of the drug, or any grade > 2 organ-specific toxicity. Patients were monitored clinically and electrophysiologically for neurotoxicity. No prolonged corticosteroid co-medication or prophylactic haematopoietic growth factors were given.

RESULTS

A median/mean number of 8.5/8.7 consecutive weekly courses were given per patient. The maximum tolerated dose that prevented on-schedule administration of the drug was 50 mg/m2. The main cumulative toxicities were a mild fluid retention and dacryorrhea which became evident as the number of treatment courses increased. Grade 2 alopecia and fatigue were observed only at 45 mg/m2 and higher. Activity was seen at all of the dose levels studied.

CONCLUSIONS

Long-term weekly administration of docetaxel is feasible at doses up to 45 mg/m2/week with acceptable toxicity. Further clinical evaluation is justified at this schedule and 40 mg/m2/week of docetaxel is proposed for phase II studies as an active dose with minimal toxicity.

Dose-finding study of docetaxel and doxorubicin in first-line treatment of patients with metastatic breast cancer

PURPOSE

To determine the maximum tolerated dose (MTD), the dose-limiting toxicity (DLT) and the recommended dose of docetaxel in combination with doxorubicin, and to evaluate the activity in patients with advanced breast cancer.

PATIENTS AND METHODS

Forty-two women with untreated metastatic breast cancer (79% with visceral metastases; 52% with prior adjuvant anthracycline therapy) were treated with doxorubicin (40-60 mg/m2) i.v. bolus followed one hour later by docetaxel (50-85 mg/m2) one-hour i.v. infusion every three weeks, without G-CSF support.

RESULTS

The MTD occurred at the dose level combining 85 mg/m2 of docetaxel and 50 mg/m2 of doxorubicin, with the DLT being neutropenic sepsis. Neutropenia and/or its complications were manageable and no grade 3-4 or severe non-hematological toxicities were observed. Fluid retention was frequent but never severe. With a median cumulative dose of doxorubicin of 392 mg/m2 (240-559 mg/m2) and a median follow-up time of 29 months (9(+)-41), no congestive heart failure was observed. High activity was observed at all dose levels, particularly the last four, with a response rate of 81% (95% confidence interval (95% CI): 62.5-92.5). Median time to progression was 46 weeks (6(+)-62). Two-year survival was 66%, and median survival has not yet been reached.

CONCLUSIONS

Docetaxel-doxorubicin is feasible, safe and highly active. The incidence of febrile neutropenia without G-CSF requires careful monitoring but is acceptable in this setting. There does not appear to be an increase in the cardiac toxicity of doxorubicin. The recommended doses is either docetaxel 75 mg/m2 and doxorubicin 50 mg/m2 or docetaxel 60 mg/m2 and doxorubicin 60 mg/m2, administered every three weeks.

The role of chemotherapy for metastatic breast cancer

Metastatic breast cancer remains a devastating and largely incurable disease. Currently available therapies offer meaningful palliation for many and modest prolongation of survival for some patients. Single-agent hormonal therapy remains the treatment of choice for patients with ER-positive disease, with sequential use of further hormonal agents or cytotoxic chemotherapy at the time of disease progression. Chemotherapy is appropriate as initial therapy for patients with receptor-negative or rapidly progressive visceral disease. Although combination regimens may increase response rates, the lack of survival benefit does not justify the increased toxicity of aggressive combination regimens in most patients. Maintenance chemotherapy deserves consideration in selected well-informed patients, especially those with few therapy-related side effects. High-dose regimens confer substantial toxicity with no clear therapeutic advantage and cannot be recommended outside of ongoing trials. New chemotherapy agents offer the hope of effective salvage therapy with acceptable toxicity to a larger number of patients. Perhaps most promising, the development of targeted, biologically based therapies such as rhuMAbHER2 offers encouragement for the future.

Monotherapy of Metastatic Breast Cancer: A Review of Newer Agents

Purpose. New agents for the palliative treatment of metastatic breast cancer have emerged in the 1990s. This review summarizes the response rates of these agents with an emphasis on recent findings, such as presentations from the 1998 Meeting of the American Society of Clinical Oncology.

Methods. The English medical literature was reviewed to identify clinical trials involving monotherapy for the treatment of metastatic breast cancer. Three agents—paclitaxel, vinorelbine, and docetaxel—are emphasized because their databases are extensive enough to allow interesting comparisons. Liposomal-encapsulated anthracyclines, losoxantrone, gemcitabine, oral surrogates of continuous-infusion fluorouracil, raltitrexed, LY 231514, edatrexate, topoisomerase I inhibitors, and trastuzumab are reviewed briefly.

Results. Many of the new agents produce response rates approaching or even surpassing those achievable with doxorubicin monotherapy. Compared with older agents, some new agents have improved or at least different safety profiles, and some are easier to administer.

Discussion and conclusions. The new agents offer useful therapeutic options that make them suitable for combining with each other and with older agents, which could result in more effective regimens for metastatic disease, and, ultimately, primary disease in the adjuvant setting. The chemotherapeutic paradigms governing the management of breast cancer for the past three decades are likely to change as we move into the 21st century.

A phase I-II study of bi-weekly paclitaxel as first-line treatment in metastatic breast cancer

BACKGROUND

Single-agent bi-weekly paclitaxel was studied as first-line metastatic treatment for breast cancer in a phase I-II trial.

PATIENTS AND METHODS

Thirty-eight women with metastatic breast cancer were enrolled. Thirty-seven are evaluable for toxicity, 35 for response.

RESULTS

The MTD was defined at 160 mg/m2 q two weeks with dose limiting toxicity in two patients consisting of hematological toxicity (1) and neurotoxicity (2). Twenty patients were treated at 150 mg/m2, the recommended dose. Response rates were two CRs and nine PRs (overall 61%) at the RD of 150 mg/m2 and three CRs and 11 PRs for an overall RR of 67% for the two top doses.

CONCLUSIONS

The good drug tolerance, response rates, and convenience over weekly treatment suggest this may be a worthwhile regimen.

Docetaxel: response in patients who have received at least two prior chemotherapy regimens for metastatic breast cancer

It is unusual to obtain responses after two different sequential regimens in patients with metastatic breast cancer. In this retrospective analysis, data were examined on 22 patients who had already received two or three different regimens for metastatic breast cancer before being treated with 100 mg/m2 docetaxel (or 75 mg/m2 if clinically warranted). 13 patients received three or more courses and 21 patients were assessable for response. 5 of 21 assessable patients (24%) responded for 3-11 months and a further 6 (29%) stabilised. Toxicity (WHO grade 3 and/or 4), principally neutropenia, stomatitis and fluid retention, occurred in 10 patients. We conclude that docetaxel is an active agent in heavily pretreated patients with metastatic breast cancer, but care should be taken to minimise side-effects in this group of patients.

Anthracycline-Resistant Breast Cancer

The management of breast cancer requires the judicious use of cytotoxic therapy, hormone therapy, radiotherapy, analgesics, and other forms of physical and psychological support for optimal palliation of symptoms and prolongation of survival. Patients with low-risk metastatic breast cancer often benefit from hormone therapy as initial management; other patients are best treated with early introduction of cytotoxic therapy. Combination chemotherapy is superior to single-agent treatment, and anthracycline-containing regimens are more effective than the rest. The development of primary or secondary resistance to anthracycline therapy represents an adverse prognostic indicator, associated, until recently, with poor response to subsequent cytotoxic therapy and short survival. Prior to the development of taxanes, response to second- and third-line chemotherapy for patients with primary anthracycline resistance was observed in 5% of patients. Paclitaxel and docetaxel retain substantial antitumor activity in anthracycline-resistant breast cancer, and vinorelbine is also moderately effective in this subset of patients. Attempts to reverse P-glycoprotein-related drug resistance, while encouraging in the laboratory, have not been successful in the clinic. A number of novel therapeutic interventions, many that bypass traditional mechanisms of drug resistance, are currently in clinical developments, with encouraging preliminary results.