Dose-response in the treatment of breast cancer: a critical review

Impact of chemotherapy schedule modification on breast cancer patients: a single-centre retrospective study

Background Nonconformity to chemotherapy schedules is common in clinical practice. Multiple clinical studies have established the negative prognostic impact of dose delay on survival outcome. Objective This study investigated the prevalence and reason for chemotherapy schedule modifications of breast cancer patients. This study also investigated the impact of schedule modifications on overall survival (OS). Setting This retrospective cohort study was done among breast cancer patient receiving chemotherapy from 2013 to 2017 and patients were followed until 31 Dec 2018. Methods Medical records of patients with cancer were reviewed. Female patients over eighteen years old were included, with primary carcinoma of the breast, who received anthracycline or taxane based chemotherapy regime and completed more than two cycles of chemotherapy. Patients were categorized into three groups of (1) no schedule modification, (2) with schedule modification and (3) incomplete schedule. The Kaplan-Meier was used to test for survival differences in the univariate setting and Cox regression model was used in the multivariate setting. Main outcome measure Prevalence, overall survival rates and hazard ratio of three schedule group Results Among 171 patient who were included in the final analysis, 28 (16.4%) had no schedule modification, 118 (69.0%) with schedule modification and 25 (14.6%) had incomplete schedule with OS of 75.0%, 59.3% and 52.0% respectively. 94% (189) of all cycle rescheduling happened because of constitutional symptoms (70), for non-medical reasons (61) and blood/bone marrow toxicity (58). When compared to patients with no schedule modification, patients with schedule modification had a 2.34-times higher risk of death (HR 2.34, 95% CI 1.03-5.32; p = 0.043). Conclusion Nonconformity to the chemotherapy schedule is common in clinical practice because of treatment complications, patients' social schedule conflicts, and facility administrative reasons. Cumulative delays of ≥ 14 days are likely to have negative prognostic effect on patient survival. Thus, the duration of the delays between cycles should be reduced whenever possible to achieve the maximum chemotherapeutic benefit.

Discovery and Optimization of Novel Hydrogen Peroxide Activated Aromatic Nitrogen Mustard Derivatives as Highly Potent Anticancer Agents

We describe several new aromatic nitrogen mustards with various aromatic substituents and boronic esters that can be activated with H₂O₂ to efficiently cross-link DNA. In vitro studies demonstrated the anticancer potential of these compounds at lower concentrations than those of other clinically used chemotherapeutics, such as melphalan and chlorambucil. In particular, compound 10, bearing an amino acid ester chain, is selectively cytotoxic toward breast cancer and leukemia cells that have inherently high levels of reactive oxygen species. Importantly, 10 was 10-14-fold more efficacious than melphalan and chlorambucil for triple-negative breast-cancer (TNBC) cells. Similarly, 10 is more toxic toward primary chronic-lymphocytic-leukemia cells than either chlorambucil or the lead compound, 9. The introduction of an amino acid side chain improved the solubility and permeability of 10. Furthermore, 10 inhibited the growth of TNBC tumors in xenografted mice without obvious signs of general toxicity, making this compound an ideal drug candidate for clinical development.

High-Dose Epirubicin as a Single Agent in the Treatment of Patients with Advanced Breast Cancer

Fifty-two women with advanced breast cancer were treated with 6 cycles of epirubicin. Even though the study was started with a dose schedule of 110 mg/m2 every 3 weeks, the average treatment interval was 26 days and the median weekly dose 78% of the protocol requirement. Forty-eight patients were evaluable for response; 3 achieved a complete remission which lasted for 17, 24 and 65 weeks, respectively, and 14 a partial remission. Median survival was 32 weeks. Toxicity included nausea/vomiting (68%), anemia (24%), leukopenia (37 %), thrombocytopenia (8 %), alopecia (81 %), stomatitis (24%), diarrhea (14%), fever (19%) and fatigue (14%). Also 1 treatment-related death occurred and 2 cases of arrhythmia. Monotherapy with high doses of epirubicin has definite activity in advanced breast cancer and deserves further study in combination with hematopoietic growth factors which might allow a higher dose Intensity.

Radioimmunotherapy for Breast Cancer: Treatment of a Patient with I-131 L6 Chimeric Monoclonal Antibody

We report the first treatment of metastatic breast cancer by systemic radioimmunotherapy. The serial therapy doses were chosen based on quantitative imaging data in a treatment planning approach. A terminally ill patient with aggressive, locally advanced breast cancer who had failed radiation treatment and chemotherapy was injected intravenously with radiolabeled I-131 chimeric L6, a human-mouse chimeric IgG1 monoclonal antibody to adenocarcinoma. Initially, an imaging 10 mCi dose of 1-131 chimeric L6 (dose 1) deposited 8.8% of the injected dose in her chest wall tumor at 48 hours. Ten days later the patient was given a 150 mCi I-131 chimeric L6 dose (dose 2) followed three weeks later by a 100 mCi dose (dose 3). Tumor uptake and retention were comparable for doses 1 and 2, and decreased for dose 3. Following dose 3 the patient developed a manageable thrombocytopenia and transient Grade IV granulocytopenia. The tumor was observed to decrease in size with peak tumor regression occurring two weeks after dose 3. This partial response (PR) was achieved by radioimmunotherapy at a time when conventional therapy had been unable to impact the growth of the patient's massive and aggressive tumor.

Change in tumor size by RECIST correlates linearly with overall survival in phase I oncology studies

PURPOSE

RECIST is used to quantify tumor changes during exposure to anticancer agents. Responses are categorized as complete response (CR), partial response (PR), stable disease (SD), or progressive disease (PD). Clinical trials dictate a patient's management options based on the category into which his or her response falls. However, the association between response and survival is not well studied in the early trial setting.

PATIENTS AND METHODS

To study the correlation between response as quantified by RECIST and overall survival (OS, the gold-standard survival outcome), we analyzed 570 participants of 24 phase I trials conducted between October 2004 and May 2009, of whom 468 had quantifiable changes in tumor size. Analyses of Kaplan-Meier estimates of OS by response and null Martingale residuals of Cox models were the primary outcome measures. All analyses are landmark analyses.

RESULTS

Kaplan-Meier analyses revealed strong associations between change in tumor size by RECIST and survival (P = 4.5 × 10(-6) to < 1 × 10(-8)). The relationship was found to be near-linear (R(2) = 0.75 to 0.92) and confirmed by the residual analyses. No clear inflection points were found to exist in the relationship between tumor size changes and survival.

CONCLUSION

RECIST quantification of response correlates with survival, validating RECIST's use in phase I trials. However, the lack of apparent boundary values in the relationship between change in tumor size and OS demonstrates the arbitrary nature of the CR/PR/SD/PD categories and questions emphasis placed on this categorization scheme. Describing tumor responses as a continuous variable may be more informative than reporting categoric responses when evaluating novel anticancer therapies.

Phase I oncology studies: evidence that in the era of targeted therapies patients on lower doses do not fare worse

PURPOSE

To safely assess new drugs, cancer patients in initial cohorts of phase I oncology studies receive low drug doses. Doses are successively increased until the maximum tolerated dose (MTD) is determined. Because traditional chemotherapy is often more effective near the MTD, ethical concerns have been raised about administration of low drug doses to phase I patients. However, a substantial portion of oncology trials now investigate targeted agents, which may have different dose-response relationships than cytotoxic chemotherapies.

EXPERIMENTAL DESIGN

Twenty-four consecutive trials treating 683 patients between October 1, 2004, and June 30, 2008, at MD Anderson Cancer Center were analyzed. Patients were assigned to a low-dose (<or=25% MTD), medium-dose (25-75% MTD), or high-dose (>or=75% MTD) group, and groups were compared for response rate, time-to-treatment failure, progression-free survival, overall survival, and toxicity. To remove negatively biasing data from the high-dose group, in a second analysis, patients treated above the MTD were excluded (high-dose group, 75-100% MTD). Of the 683 patients, 97.7% received targeted agents.

RESULTS

Even when excluding patients above the MTD, there was an early trend favoring the low- versus high-dose group in time-to-treatment failure, with 32.9% versus 25.2% of patients on therapy at 3 months (P = 0.08). In addition, the low-dose group fared at least as well as the other groups in all other outcomes, including response rate, progression-free survival, overall survival, and toxicity.

CONCLUSIONS

These data may help alleviate concerns that patients who receive low drug doses on contemporary phase I oncology trials fare worse and suggest targeted agents may have different dose-response relationships than cytotoxic chemotherapies.

Lessons learned from a decade of clinical trials of high-dose chemotherapy in ovarian cancer

Ovarian cancer is one of the most chemosensitive solid tumors and therefore a good example to explore high-dose chemotherapy (HDC). Interest in pursuing this treatment arose in the late 1980s following the success of HDC in treating hematological cancers and improvements in supportive care with peripheral blood stem cells. Experience from phase II trials and analysis of Bone Marrow Transplant Registry data led to the launch of several randomized phase III trials in the late 1990 s. Initial enthusiasm for this treatment was in part due to the preliminary positive data emerging from HDC in breast cancer. Five randomized trials of HDC in ovarian cancer have been conducted and all experienced difficulty in recruitment. Their different designs and results are reviewed, as well as some of the lessons that have been learned about HDC in solid tumors in the last decade.

Dose-escalation of filgrastim does not improve efficacy: clinical tolerability and long-term follow-up on CALGB study 9141 adjuvant chemotherapy for node-positive breast cancer patients using dose-intensified doxorubicin plus cyclophosphamide followed by paclitaxel

PURPOSE

To assess the safety, tolerability, and clinical outcomes of an adjuvant chemotherapy regimen designed to incorporate a non-cross-resistant agent (paclitaxel, T) with a maximally dose-intensified regimen of doxorubicin and cyclophosphamide (AC) in conjunction with hematopoietic growth factor support (recombinant human granulocyte-colony stimulating factor; G-CSF; Filgrastim). A secondary aim was to assess if a higher dose (10 mcg/kg/day) of G-CSF is more efficacious than the conventional dose (5 mcg/kg/day) in this setting.

PATIENTS AND METHODS

Female patients with early-stage, node-positive invasive breast cancer were eligible for this multicenter, cooperative group feasibility trial that was designed as the pilot study for a larger randomized clinical trial. The protocol treatment comprised five cycles of dose-intensified AC (75 and 2000 mg/m(2)/cycle, respectively, intravenously every three weeks) with G-CSF support, followed by an additional four cycles of T (175 mg/m(2) by 3h intravenous infusion, every three weeks). Patients were randomized to receive one of two dose levels of G-CSF (5 vs. 10 mcg/kg/day) during AC chemotherapy. Data on both short-term toxicity and long-term survival were collected.

RESULTS

One hundred and seventy two node-positive patients with operable primary breast cancer were accrued to this trial between February 1993 and April 1994. 130 of the 172 patients (76%) completed all protocol-specified therapy. Of the 42 early study withdrawals, 23 were due to unacceptable acute treatment-related toxicity. No differences in toxicities or clinical outcomes were noted between the two different dose levels of G-CSF support. At 6.8 years median follow-up, relapse-free survival (RFS) and overall survival (OS) rates for all patients are 70% and 78%, respectively. Ten patients developed second malignancies during follow-up, including three cases with a hematologic malignancy (2% incidence).

CONCLUSION

The delivery of dose-intensified AC followed by T was feasible in this large-scale pilot trial, although significant acute toxicities were commonly encountered. The data confirmed the acceptable tolerability of T after aggressive myelotoxic therapy in the adjuvant setting, leading to a larger randomized clinical trial comparing three dose levels of doxorubicin in AC with or without the addition of T (CALGB 9344). Supportive care using twice the conventional dose of G-CSF did not significantly improve the tolerability or change the toxicities of this regimen, and the occurrence of secondary malignancies is consistent with the emerging risk profile of dose-intensive regimens with growth factor support. With long-term follow-up, the clinical outcomes remain relatively favorable and correlate with such expected prognostic factors as the number of involved nodes and hormone receptor status.

Prolonged clinical benefit with metronomic chemotherapy in patients with metastatic breast cancer

The clinical efficacy and antiangiogenic effect of low-dose, metronomic administration of cyclophosphamide (CTX) and methotrexate (MTX) (CM) have been demonstrated. The authors report results and long-term follow-up for patients with metastatic breast carcinoma who obtained prolonged clinical benefit with CM. Prospectively collected data from two successive clinical trials were evaluated. From July 1997 to October 2003, patients with metastatic breast carcinoma were treated with low-dose oral chemotherapy (MTX 2.5 mg, twice daily on day 1 and day 2 or 4, and CTX 50 mg daily). Patients who achieved prolonged clinical benefit for a duration of 12 months or more (complete remission, partial remission or stabilization of disease) were considered for the analysis. Median follow-up was 23 months. A total of 153 patients were enrolled and are evaluable: Eastern Cooperative Oncology Group performance status 0-1 in 90 patients, two or more sites of metastatic disease in 97 patients, zero regimen for metastatic breast carcinoma in 48 patients. Among 153 patients, five demonstrated complete remission and 25 partial remission. The proportion of patients who achieved prolonged clinical benefit was 15.7% (95% confidence interval 9.9-21.4%). Median time to progression for patients with prolonged clinical benefit was 21 months (range 12-37+ months). One patient maintained complete remission 42 months after therapy discontinuation. At the multivariate analysis endocrine responsiveness and the achievement of an objective response significantly correlated with the achievement of prolonged clinical benefit. Metronomic chemotherapy can induce prolonged clinical benefit in metastatic breast cancer, supporting its role as an additional therapeutic tool in the treatment of patients with metastatic breast carcinoma.

Phase II clinical trial results involving treatment with low-dose daily oral cyclophosphamide, weekly vinblastine, and rofecoxib in patients with advanced solid tumors

PURPOSE

Preclinical studies indicate that conventional chemotherapeutic agents given continuously at low doses (metronomic chemotherapy) may provide an improved therapeutic index. Cyclophosphamide and vinblastine have been best studied in experimental models, where tumor growth inhibition is achieved, at least in part, through antiangiogenic mechanisms.

EXPERIMENTAL DESIGN

Fifty patients with advanced solid tumors were enrolled in this phase II trial, 43 of whom had received at least one prior chemotherapy regimen. Patients were required to have Eastern Cooperative Oncology Group performance status of < or = 2, a life expectancy of >3 months, and at least one measurable lesion. All patients received oral cyclophosphamide (50 mg) and rofecoxib (25 mg) daily in addition to weekly injections of vinblastine (3 mg/m2). Half of the patients also received minocycline (100 mg) orally twice daily with the intent of further inhibiting tumor angiogenesis. The primary end point of the study was clinical benefit, defined as the percentage of patients experiencing an objective response or exhibiting stable disease for at least 6 months.

RESULTS

For the 47 eligible patients, there were two (4%) complete responses and four (9%) partial responses, for an overall objective response rate of 13%. An additional eight patients achieved disease stabilization (stable disease > or = 6 months) (17%). The primary end point of clinical benefit was therefore 30%, (95% confidence interval, 16-44%). The median progression-free survival for all patients was 103 days and 289 days for patients experiencing clinical benefit. The incidence of patients experiencing grade 3/4 toxicities were as follows: neutropenia (10/2), anemia (2/0), and thrombocytopenia (1/0). No patients developed grade 3 or 4 nausea, vomiting, mucositis, or alopecia.

CONCLUSIONS

This low-dose regimen consisting of daily oral cyclophosphamide and weekly vinblastine injections given concurrently with rofecoxib is associated with minimal toxicity and provides significant clinical benefit to patients with advanced solid tumors. These results are particularly encouraging given the nature of the study population and indicate that this approach merits further investigation in specific disease site studies.

Randomized trial of high-dose chemotherapy and autologous hematopoietic stem cell support for high-risk primary breast carcinoma: follow-up at 12 years

BACKGROUND

The authors previously reported results from a randomized trial of standard-dose chemotherapy with combined 5-fluorouracil (1000 mg/m2 per cycle), doxorubicin (50 mg/m2 per cycle), and cyclophosphamide (500 mg/m2 per cycle) (FAC) versus FAC followed by high-dose chemotherapy (HDCT) and autologous stem cell support (ASCS) for patients with high-risk primary breast carcinoma. After a median follow-up of 6.5 years, no significant differences were observed in recurrence-free survival (RFS) or overall survival (OS) between the 2 arms. This report updates the survival analyses.

METHODS

Patients with >or=10 positive axillary lymph nodes after primary surgery or >or=4 positive lymph nodes at surgery after neoadjuvant chemotherapy were eligible. All patients were to receive 8 cycles of FAC. Patients were assigned randomly to receive either no further chemotherapy or 2 cycles of combined high-dose cyclophosphamide (5250 mg/m2 per cycle), etoposide (1200 mg/m2 per cycle), and cisplatin (165 mg/m2 per cycle) with ASCS. Primary endpoints were RFS and OS. RFS and OS were calculated by using the Kaplan-Meier method. The log-rank statistic was used to compare treatment arms.

RESULTS

Between 1990 and 1997, 78 patients were registered, and 39 patients were assigned randomly to each arm. The median follow-up for all patients who were alive at last follow-up was 142.5 months (range, 45-169 months). An intention-to-treat analysis showed no significant difference between the 2 arms in terms of RFS (at 10 years: 40% with FAC vs. 26% with FAC plus HDCT; P=.11) or OS (at 10 years: 47% with FAC vs. 42% with FAC plus HDCT; P=.13).

CONCLUSIONS

With a median follow-up of nearly 12 years for patients who remained alive, this trial continued to demonstrate no RFS or OS advantage for patients with high-risk primary breast carcinoma treated with HDCT after standard-dose FAC chemotherapy.

Population analysis of the pharmacokinetics and the haematological toxicity of the fluorouracil-epirubicin-cyclophosphamide regimen in breast cancer patients

PURPOSE

The aims of the study were (a) to characterise the pharmacokinetics (PK), including inter-individual variability (IIV) and inter-occasion variability (IOV) as well as covariate relationships and (b) to characterise the relationship between the PK and the haematological toxicity of the component drugs of the fluorouracil (5-FU)-epirubicin (EPI)-cyclophosphamide (CP) regimen in breast cancer patients.

PATIENTS AND METHODS

Data from 140 breast cancer patients, either within one of different studies or in routine clinical management, were included in the analyses. The patients were all treated with the fluorouracil-epirubicin-cyclophosphamide (FEC) regimen every third week for 3-12 courses, either in standard doses, i.e. 600/60/600 mg/m(2) of 5-FU, EPI and CP, respectively, or according to a dose escalation/reduction protocol (tailored dosing). PK data were available from 84 of the patients, whereas time-courses of haematological toxicity were available from 87 patients. The data analysis was carried out using mixed effects models within the NONMEM program.

RESULTS

The PK of 5-FU, EPI and 4-hydroxy-cyclophosphamide (4-OHCP), the active metabolite of CP, were described with a one-compartment model with saturable elimination, a three-compartment linear model and a two-compartment linear model, respectively. No clinical significant correlation was found between PK across drugs. The unexplained variability in clearance was found to be less within patients, between courses (inter-occasion variability, IOV) than between patients (inter-individual variability, IIV) for EPI and 5-FU. For 4-OHCP, however, the IIV diminished by approximately 45% when significant covariates were included and the final population model predicts an IIV that is equal to IOV. Significant covariates for elimination capacity parameters were serum albumin (5-FU, EPI and 4-OHCP), creatinine clearance (5-FU), bilirubin (EPI) and body surface area (BSA) (4-OHCP). Elimination capacity of 5-FU and EPI was not related to BSA and for none of the studied drugs did body weight explain the PK variability. The time-course of haematological toxicity after treatment was well described by a semi-physiological model that assumes additive haematological toxicity between CP and EPI with negligible contribution from 5-FU. The influence of G-CSF could be incorporated into the model in a mechanistic manner as shortening the maturation time to 43% of the normal duration and increasing the mitotic activity to 269% of normal activity.

CONCLUSIONS

The models presented describe the dose-concentration-toxicity relationships for the FEC therapy and may provide a basis for implementation and comparison of different individualisation strategies based on covariates, therapeutic drug monitoring and/or pharmacodynamic (PD) feedback. The PD model extends on previous semi-mechanistic models in that it also takes G-CSF administration into account.

Relation between chemotherapy dose, oestrogen receptor expression, and body-mass index

Clinicians often reduce chemotherapy doses when treating obese patients because of concerns about overdosing. We assessed dose-response according to body-mass index (BMI) and oestrogen receptor (ER) expression of the primary tumour in premenopausal patients with node-positive breast cancer treated with classical CMF (cyclophosphamide, methotrexate, and 5-fluorouracil). Obese patients were significantly more likely to receive a lower chemotherapy dose (<85% of expected dose) for the first course than were those with normal or intermediate BMI (39%vs 16%, p<0.0001). For obese patients and for the total population, reducing the dose of chemotherapy was associated with a significantly worse outcome for the ER-negative cohort (total population hazards ratio 85%vs <85% 0.68 [95% CI 0.54-0.86] for disease free survival; 0.72 [0.56-0.94] for overall survival) but not for the ER-positive cohort (1.16 [0.97-1.40] for disease-free survival; 1.16 [0.94-1.44] for overall survival) [interaction p values=0.0001 for disease-free survival and 0.0019 for overall survival]. Our findings suggest that for women with ER-absent or ER-low tumours, reduction in chemotherapy dose should be avoided.

Establishing a platform for immunotherapy: clinical outcome and study of immune reconstitution after high-dose chemotherapy with progenitor cell support in breast cancer patients

Tumor vaccine after high-dose chemotherapy (HDC) and autologous stem cell transplantation (ASCT) aims at directing immune recovery toward tumor responses after optimizing minimal residual disease. We have characterized T-cell recovery and tumor response after a regimen devised as a platform for such immunotherapy. One hundred patients with high-risk or metastatic breast cancer received 3 to 7 cycles of paclitaxel and cyclophosphamide (overall response rate, 78%) and then HDC with melphalan and etoposide. Seventy-one patients received HDC and ASCT (no mortality at 100 days). At 24 months after transplantation, progression-free and overall survival probabilities for patients with stage IIIA, IIIB, and IV disease were 82%, 81%, and 42% and 100%, 94%, and 68%, respectively. The median progression-free and overall survivals from entry on study for stage IV patients were 15.3 and 38.1 months, respectively. CD3 + , CD8 + , and CD4 + cells were severely depleted after ASCT. Although total CD8 + T-cell numbers approached the normal range by 3 months, most of these cells were CD28 - . Naive CD45RA + CD4 + T cells approached the normal range only 18 months after ASCT and only in younger patients. The described observations provide the basis for devising a strategy for cancer vaccine administration after ASCT. Incorporating immune reconstitution enhancement after ASCT may be advantageous.

High-Dose Chemotherapy and Autologous Stem Cell Rescue for Metastatic Breast Cancer

During 1990-1999, we treated 60 patients with breast cancer who had distant metastases with high-dose chemotherapy and autologous stem cell rescue (HDC) after they had responded to induction chemotherapy. HDC regimens were MiTepa (60 mg/m2 mitoxantrone by continuous intravenous infusion over 3 days plus 300 mg/m2 thiotepa intravenously over 2 hours daily x 3 days) and ICE (12 g/m2 ifosfamide, 1800 mg/m2 carboplatin, 2 g/m2 etoposide; all 3 by continuous intravenous over 4 days). At a median follow up >8 years, the median failure-free survival (FFS) was 13.9 months, median overall survival (OS) 29.1 months, 5-year FFS 12%s and 5-year OS 25%. Thirty-three patients underwent tandem (T) transplants; 27 underwent a single (S) HDC. Median ages for these 2 groups were 45 and 48 years; bone and liver metastases were more prevalent in the T cohort, whereas lung metastases were more prevalent in the S cohort. At a median follow up of 6.5 years for the S group and >9 years for the T group, there were 52 deaths. FFS was better for T: median 15.7 versus 7.7 months (p2 = 0.010) as was OS: median 32.7 versus 17.7 months, 2-year survival 68% versus 41%, and 5-year survival 32% versus 15% (p2 = 0.010). As a group, patients with distant metastatic breast cancer who underwent tandem transplants had a better posttransplant survival than patients who underwent a single HDC.

Model Describing the Relationship Between Pharmacokinetics and Hematologic Toxicity of the Epirubicin-Docetaxel Regimen in Breast Cancer Patients

Purpose

The aims of the present study were (1) to characterize the pharmacokinetics of both component drugs and (2) to describe the relationship between the pharmacokinetics and the dose-limiting hematologic toxicity for the epirubicin (EPI)/docetaxel (DTX) regimen in breast cancer patients.

Patients and Methods

Forty-four patients with advanced disease received EPI and DTX every 3 weeks for up to nine cycles. The initial doses (EPI/DTX) were 75/70 mg/m2. Based on leukocyte (WBC) and platelet counts, the subsequent doses were, stepwise, either escalated (maximum, 120/100 mg/m2) or reduced (minimum, 40/50 mg/m2). Hematologic toxicity was monitored in all patients, whereas pharmacokinetics was studied in 16 patients. A semiphysiological model, including physiological parameters as well as drug-specific parameters, was used to describe the time course of WBC count following treatment.

Results

In the final pharmacokinetic model, interoccasion variability was estimated to be less than interindividual variability in the clearances for both drugs. The sum of the individual EPI and DTX areas under concentration-time curve correlated stronger to WBC survival fraction than did the corresponding sum of doses. A pharmacokinetic-pharmacodynamic (PK-PD) model with additive effects of EPI and DTX could adequately describe the data.

Conclusion

The final PK-PD model might provide a tool for calculation of WBC time course, and hence, for prediction of nadir day and duration of leukopenia in breast cancer patients treated with the EPI/DTX regimen.

High-dose chemotherapy with haematopoietic stem cell transplantation for metastatic breast cancer patients: final results of the French multicentric randomised CMA/PEGASE 04 protocol

The aim of our study was to evaluate the impact on time to progression (TTP) and overall survival (OS) of high-dose chemotherapy (HD-CT) over conventional CT in metastatic breast cancer patients. Between 09/92 and 12/96, 61 patients with chemosensitive metastatic breast cancer were randomised between HD-CT using the CMA regimen (Mitoxantrone, Cyclophosphamide, Melphalan) applied as consolidation (32 patients) or maintenance CT (29 patients). At randomisation, 13 patients were in complete response, 47 in partial response and one had stable disease. The median TTPs from randomisation were 6 and 12 months in the standard and intensive groups, respectively (P < 0.0056), with a relapse rate of 86.2% vs. 62.5% at 2 years, and 100% vs. 81.3% at 5 years. The median OS times were 19.3 and 44.1 months, with an OS rate of 13.8% vs. 36.8% at 5 years (P < 0.0294). The CMA regimen could prolong the TTP of patients with chemosensitive metastatic breast cancer. Further studies are needed to determine if this translates into an effect on OS.

A Pilot Study of Dose Intense Doxorubicin and Cyclophosphamide Followed by Infusional Paclitaxel in High-Risk Primary Breast Cancer

We conducted a pilot study of dose dense doxorubicin and cyclophosphamide (AC) combination chemotherapy followed by infusional paclitaxel (T) in primary breast cancer to determine its safety and feasibility. Twenty-two subjects (10 with stage II and > or = 4 positive lymph nodes, and 12 with stage III disease) were treated with AC (A 60 mg/m2 and C 2000 mg/m2) with filgrastim every 14 days for three cycles followed by infusional paclitaxel (140 mg/m2 over 96 h) every 14 days for three cycles. Mean overall cycle length was 15.3 days and mean duration of therapy was 92 days. Dose reductions of C or T were required in 7/132 (5.3%) cycles for mucositis, diarrhea, or failure to recover platelets by day 15. Ninety-five percent of subjects had grade 4 neutropenia and 1 subject had a platelet nadir of < 20,000. Actual delivered dose intensity (DI) over six cycles was: A 27 mg/m2 per week; C 892 mg/m2 per week; T 64 mg/m2 per week (90.6, 89.2, and 91.4% of planned DI, respectively). Average total dose administered was: A 180 mg/m2; C 5880 mg/m2; T 403 mg/m2 (100, 98, and 96% of planned total doses, respectively). Clinical response rate in 10 subjects receiving neoadjuvant therapy was 100% (4 complete response, 6 partial response). Four subjects had a pathologic complete response (three subjects without evidence of malignancy and one subject with ductal carcinoma in situ.) Administration of dose dense AC followed by infusional paclitaxel in 14-day cycles is feasible and this regimen is active in breast cancer.

Docetaxel plus vinorelbine as salvage chemotherapy in advanced breast cancer: a phase II study

PRECIS

Administration of a combined regimen of docetaxel plus vinorelbine every 4 weeks is feasible and shows activity in heavily pretreated patients with advanced breast cancer.

PURPOSE

To determine the activity and tolerance of docetaxel plus vinorelbine in heavily pretreated patients with advanced breast cancer.

METHODS

Thirty-five metastatic breast cancer patients with ECOG performance status of 0-2 received docetaxel (80 mg/m2 given intravenously) on day 1 and vinorelbine (30 mg/m2 given intravenously) on days 1 and 14, every 4 weeks. The median number of prior chemotherapy regimens was 2 (range: 1-4). Twenty-five patients (71.4%) had been treated previously using intensive therapy approaches with peripheral blood-derived stem cell (PBSC) support, including high-dose chemotherapy (11 patients), multicyclic dose-intensive chemotherapy supported with repeated PBSC infusions (seven patients), or both (seven patients). Twenty-eight patients (80%) received previous chemotherapy for metastatic disease. Adjuvant therapy in the remaining seven patients consisted of high-dose chemotherapy and PBSC support or an anthracycline-containing regimen.

RESULTS

The total number of courses was 229, and the median number of courses per patient was 6 (range: 1-16). There was one toxic death (2.8%). Grade 3-4 toxicities included mucositis (17.1%), neutropenia (37.1%), anemia (5.7%), vomiting (2.9%), and asthenia (14.3%). Eighteen patients (58%; 95% CI: 40.6-75.4%) achieved an objective response, including four complete responses (12.9%) and 14 partial responses (45.1%). Overall response rate was 51.4% (95% CI: 34.8-67.9%). After a median follow-up of 20 months (range: 2-42), overall survival was 20 months (95% CI: 16-24), and median time to progression was 13 months (95% CI: 7-19).

CONCLUSION

This combination shows activity and an acceptable toxicity profile in patients with advanced breast cancer.

Progress in systemic chemotherapy of primary breast cancer: an overview

Substantial progress has been made in the multidisciplinary management of primary breast cancer during the last 30 years. Adjuvant chemotherapy has been shown to significantly reduce the annual risk of cancer recurrence and mortality, and these effects persist even 15 years after diagnosis. Combination chemotherapy is superior to single-agent therapy and anthracycline-containing regimens. Those that combine an anthracycline with 5-fluorouracil and cyclophosphamide are more effective than regimens without an anthracycline. Six cycles of a single regimen appear to provide optimal benefit. Dose reductions below the standard range are associated with inferior results. Dose increases that require growth factor or hematopoietic stem cell support are under investigation; at this time, the existing results provide no compelling reason to use this strategy outside a clinical trial. Regimens using fixed crossover designs with two non-cross-resistant regimens are being evaluated. The addition of a taxane to anthracycline-containing regimens is currently under intense scrutiny, and preliminary analysis of the first three clinical trials has shown encouraging, albeit not compelling, results. For patients with estrogen receptor-positive breast cancer, the sequential administration of chemotherapy and 5 years of tamoxifen therapy provides additive benefits. No compelling evidence exists to combine ovarian ablation with chemotherapy. Most side effects and toxic effects are self-limited, although premature menopause requires monitoring and preventive interventions to preserve bone mineral density. The small risk of acute leukemia is of concern, and additional research to develop safer regimens is clearly indicated. The overall effect of optimal local/regional treatment combined with an anthracycline-containing adjuvant chemotherapy and a taxane (and, for patients with estrogen receptor-positive tumors, 5 years of tamoxifen therapy) is a greater than 50% reduction in annual risks of recurrence of and death from breast cancer. For most patients at intermediate or high risk of cancer recurrence, the benefits of adjuvant chemotherapy exceed by far its unwanted effects.

The feasibility of classical cyclophosphamide, methotrexate, 5-fluorouracil (CMF) for pre- and post-menopausal node-positive breast cancer patients in a Belgian multicentric trial: a study of consistency in relative dose intensity (RDI) and cumulative doses across institutions

BACKGROUND

Classical cyclophosphamide, methotrexate, 5-fluorouracil (CMF) including oral cyclophosphamide is still considered an important adjuvant chemotherapy regimen in patients with early breast cancer (BC). Concern has been raised regarding the feasibility of this regimen, especially in postmenopausal patients.

PATIENTS AND METHODS

254 pre- and post-menopausal node-positive BC patients aged < or = 70 years received six cycles of CMF in the context of a Belgian multicentric phase III trial of adjuvant chemotherapy. CMF dose and schedule were as follows: cyclophosphamide 100 mg/m2 p.o. on days 1 to 14, methotrexate 40 mg/m2 intravenously (i.v.) on days 1 and 8, 5-fluorouracil 600 mg/ml i.v. on days 1 and 8; cycles q. 28 days. The relative dose intensity (RDI) was calculated as the ratio between the delivered DI and the planned DI. We also analysed the RDI in two subgroups of patients with age > or = 50 years or < 50 years.

RESULTS

Overall, the percentage of patients ending the six cycles of the planned CMF regimen was 90%. The mean RDI achieved in the population of 254 patients was 90% (range 8% to 129%). The subgroup analysis of patients aged > or = 50 years and < 50 years showed that 81% and 76% of patients, respectively, received > or = 80% of the planned chemotherapy dose intensity (P = 0.33). No statistically significant difference was found between the percentage of patients who received a RDI < 80% and the participating institutions (P = 0.50).

CONCLUSIONS

The classical CMF regimen was a feasible regimen in the context of a multicentric trial, in which academic institutions as well as community hospitals participated. No substantial differences in RDI and cumulative doses were found in relation to a patient's age and the participating institution.

Low-dose oral methotrexate and cyclophosphamide in metastatic breast cancer: antitumor activity and correlation with vascular endothelial growth factor levels

BACKGROUND

Anticancer chemotherapy is thought to be effective by means of direct cytotoxicity on tumor cells. Alternative mechanisms of efficacy have been ascribed to several common anticancer agents, including cyclophosphamide (CTX), methotrexate (MTX), anthracyclines and taxanes, postulating an antiangiogenic activity.

PATIENTS AND METHODS

We evaluated the clinical efficacy and impact on serum vascular endothelial growth factor (VEGF) levels of low-dose oral MTX and CTX in patients with metastatic breast cancer. MTX was administered 2.5 mg bd on days 1 and 2 each week and CTX 50 mg/day administered continuously.

RESULTS

Sixty-four patients were enrolled, 63 were evaluable: Eastern Cooperative Oncology Group (ECOG) performance status 0-1, > or =2 sites of metastatic disease (n = 50 patients), progressive disease at study entry (n = 51), 1 regimen for metastatic disease (n = 32) and > or =2 regimens (n = 20). Among the 63 evaluable patients, there were two complete remissions (CR), 10 partial remissions (PR) for an overall response rate of 19.0% (95% CI 10.2% to 30.9%) and an overall clinical benefit (CR+ PR+ stable disease >24 weeks) of 31.7% (95% CI 20.6% to 44.7%). Grade > or =2 leucopenia was registered in only 13 patients. The median serum VEGF level for the subgroup of patients on treatment for at least 2 months decreased with treatment from 315 pg/ml (95% CI 245 to 435) at baseline to 248 pg/ml (95% CI 205 to 311) at 2 months (P <0.001). Both responders and non-responders showed similar reductions in serum VEGF (P = 0.78). After 6 months patients still on treatment had a median VEGF level of 195 pg/ml (95% CI 96 to 355), which was significantly lower than the median baseline values (P = 0.001).

CONCLUSIONS

Continuously low-dose CTX and MTX is minimally toxic and effective in heavily pretreated breast cancer patients. A drop in VEGF was associated with the treatment and so alternative hypotheses, other than that of direct toxicity on tumor cells, must be favored when trying to explain the anticancer effect.

Combined 5-fluorouracil infusion with fractionated epirubicin and cyclophosphamide in advanced breast cancer

5-Fluorouracil (5-FU) given by continuous infusion (c.i.) allows higher dose delivery, causes less myelosuppression, and may interfere with repair of DNA damage caused by epirubicin and cyclophosphamide. With this rationale, we conducted a phase II study to test the activity and toxicity of 5-FU c.i., epirubicin, and cyclophosphamide in patients with metastatic breast cancer (MBC). Twenty-eight patients with MBC were entered in the trial. 5-FU (200 mg/m(2)) was administered by c.i. from day 1 to day 20. Epirubicin (35 mg/m(2)) and cyclophosphamide (400 mg/m(2)) were administered from day 2 to day 4, every 4 weeks. All patients were evaluable for response and toxicity. A total of 125 courses of chemotherapy were administered, with a median of 4 per patient (range: 2--6). Toxicity, assessed using World Health Organization criteria, was as follows: nausea and vomiting grade III--IV occurred in 36%, alopecia (grade III) in 86%, neutropenia (grade III--IV) in 50%, and cardiac toxicity grade I--II in 11% of patients. Five patients (17.9%) had a complete response to therapy, and 16 (57.1%) had a partial response (response rate 75%, 95% CI 55--89%). Disease stability and progression occurred in 4 (14.3%) and 3 (10.7%) patients, respectively. Median time to progression was 13.1 months (range: 3.4--66.9+), and median survival time was 27.7 months (range: 5.4--67.1+). Outpatient treatment with combined 5-FU c.i., epirubicin, and cyclophosphamide shows high activity in advanced breast cancer and gives prolonged remission with acceptable toxicity.

High-dose chemotherapy with hematopoietic stem-cell transplantation for breast cancer: current status, future trends

High-dose chemotherapy with hematopoietic stem-cell transplantation (HDC/HSCT) has been extensively studied as a potential treatment for breast cancer. A literature search of MEDLINE from January 1990 through December 1999 identified 497 published full papers. Of these articles, 120 reported the results of clinical trials, 78 were reviews, and 299 reported on issues related to the technology of peripheral stem cells, supportive care, and toxicity. The phase II data must be interpreted with caution, as it is subject to selection bias; transplant recipients tended to be younger, rigorously staged, and selected to be chemotherapy responsive. There continues to be controversy regarding the role of high-dose therapy in this disease. Only a few fully published randomized trials are available; these studies were powered only to detect large differences in survival and no benefit was shown. Several large controlled trials are either in progress or are too early for definitive analysis. This review analyzes the current literature on HDC/HSCT for breast cancer, identifying prognostic factors and discussing ongoing research designed to improve antitumor effects.

High dose chemotherapy: rationale and results in breast carcinoma

BACKGROUND

High dose chemotherapy (HDC) with hematopoietic stem cell support is an increasingly important strategy in the management of advanced cancer. Early Phase II studies and the development of peripheral blood stem cell support to enable safe and tolerable myeloablative chemotherapy has resulted in its controversial and widespread use in the management of breast carcinoma. Recently, several randomized trials of both advanced breast carcinoma and the adjuvant setting have been reported.

METHODS

The technical developments in HDC and results from the randomized clinical trials reported to date were reviewed.

RESULTS

Three randomized trials of advanced breast carcinoma and five of high risk adjuvant patients were identified. Only two relatively small trials from South Africa have so far shown an advantage for high dose chemotherapy, and the validity of these trials has recently been seriously challenged. A Scandinavian adjuvant trial showed no advantage for HDC when compared with maximum nonablative doses supported with granulocyte-colony stimulating factor (G-CSF). Four trials were too small to detect clinically realistic differences in outcome, whereas the other large adjuvant trial was reported prematurely and the results in the HDC arm were dominated by high procedure-related mortality.

CONCLUSIONS

It is difficult to make specific treatment recommendations based on the conclusions from the currently available data. The 1999 American Society of Clinical Oncology reports were inconsistent and in some cases were presented before the results were sufficiently mature to provide statistically reliable data. However, it is clear that, unlike in leukemia, lymphoma, and multiple myeloma, HDC in breast carcinoma should not be used outside the context of a clinical trial. The mature results of the ongoing trials are eagerly awaited, whereas the use of immediate as opposed to consolidation high dose treatment, tandem transplants, and developments in immunologic and genetic manipulation of the graft merit further evaluation.

Dose-dense epirubicin and paclitaxel with G-CSF: a study of decreasing intervals in metastatic breast cancer

Anthracyclines and taxanes are very effective drugs in the treatment of advanced breast cancer. With G-CSF support, the dose-intensity of this combination can be increased by reducing the interval between chemotherapy cycles, the so-called 'shortening of cycle time'. We treated 36 patients with advanced breast cancer in a multicentre phase I/II study. The treatment regimen consisted of epirubicin 75 mg m(-2) followed by paclitaxel 135 mg m(-2) (3 h) in combination with G-CSF. At least six patients were treated in each cohort and were evaluated over the first three cycles. Starting at an interval of 14 days, in subsequent cohorts of patients the interval could be shortened to 10 days. An 8-day interval was not feasible due mainly to incomplete neutrophil recovery at the day of the next scheduled cycle. In the 10-day interval cohort it was feasible to increase the paclitaxel dose to 175 mg m(-2). The haematological and non-haematological toxicity was relatively mild. No cumulative myelosuppression was observed over at least three consecutive cycles. In combination with G-CSF, epirubicin 75 mg m(-2) and paclitaxel 175 mg m(-2) could be safely administered every 10 days over at least three cycles, enabling a dose intensity of 52 and 122 mg m(-2) per week, respectively.

A phase III study of high-dose intensification without hematopoietic progenitor cells support for patients with high-risk primary breast carcinoma

Patients with more than nine ipsilateral lymph node involvement or inflammatory breast cancer have a 5-year survival rate of approximately 50%. We studied the efficacy of high-dose intensification, comparing it with the standard dose chemotherapy for patients with high-risk primary breast cancer. Patients with inflammatory breast cancer or more than nine ipsilateral lymph node involvement without evidence of distant metastasis were randomized to receive either standard dose 5-fluorouracil, doxorubicin, and cyclophosphamide (FAC) every 3 weeks for nine courses (control) or six courses of FAC followed by two courses of cyclophosphamide (5.25 g/m2), etoposide (1,500 mg/m2), and cisplatin (165 mg/m2) (HDCVP). The study was terminated in 1998 because of slow accrual of patients. Forty-six patients were entered in the study. At 4 years, the overall survival was 72.8% (SE 11.9%) and 61.7% (SE 12.4%), and disease-free survival were 45.5% (SE 12.3%) and 33.7% (SE 11.9%) for the control and HDCVP groups, respectively (p = 0.757 and 0.720). With the small number of patients in our study, a small overall survival benefit of high-dose intensification compared with the standard therapy cannot be excluded. However, any substantial benefit is unlikely.

High-dose chemotherapy and peripheral blood progenitor cell transplantation in the treatment of breast cancer

Each year in the USA, 180,000 new cases of breast cancer are diagnosed and about 44,000 women die of the disease. Current primary treatment consists of adjuvant chemotherapy and hormone therapy, and statistics show that combination chemotherapy favorably influences the outcomes in both node-negative and node-positive primary disease. However, a significant number of breast cancer patients succumb to the disease, and nearly every patient diagnosed with metastatic breast cancer will be dead within five years. High-dose chemotherapy (HDC) and peripheral blood progenitor cell transplantation (PBPCT) are based upon laboratory and clinical observations of the ability to modify growth properties of quiescent and replicating cancer cells. A large number of HDC and PBPCT regimens have been evaluated for treatment of metastatic breast cancer, and recent autologous bone marrow transplantation data indicate that three HDC regimens (CPB, CTCb and cytoxan and thiotepa) predominate. Unfortunately, negative media coverage surrounding and subsequent to the presentation of preliminary findings reported at the May 1999 American Society of Clinical Oncologists, that were not allowed adequate follow-up time for full analysis of treatment results, has had a detrimental effect on the ability to conduct trials in this area. Several randomized trials have been conducted in both the metastatic and high risk primary disease settings. Thorough analysis of these studies indicates an evaluable improvement in favor of HDC and PBPCT in three of the four randomized studies performed in metastatic breast cancer and two of the four high risk primary studies. Also, initial evaluations found that quality of life appeared comparable in patients receiving either HDC or not. Each randomized trial studied asks a different question and, depending on the intensity of HDC regimen, the intensity and duration of the standard dose chemotherapy control and the schedule of events in relation to induction chemotherapy, the outcomes may be quite variable. Still, certain general trends are indentifiable. HDC alone will not completely cure breast cancer and should be considered as part of an overall therapeutic plan. In some of these studies, significantly longer follow-up is required before definitive analysis can be completed.

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.

A phase II trial of high dose epirubicin in patients with advanced breast carcinoma

BACKGROUND

Anthracyclines are among the most active drugs in the treatment of breast carcinoma and exhibit a steep dose-response curve in vitro. This trial was performed to determine the efficacy and toxicity of epirubicin in the treatment of patients with advanced breast carcinoma when administered as a single agent in maximal doses.

METHODS

Patients with chemotherapy-naïve American Joint Committee on Cancer/International Union Against Cancer Stage IIIB or IV breast carcinoma received epirubicin, 180 mg/m(2), intravenously every 3 weeks for a maximum of 8 cycles of therapy. Hematopoietic growth factors and cardioprotective agents were not used routinely.

RESULTS

Twenty-seven patients were entered in the study. Although NCI/CTC criteria Grade 4 neutropenia occurred in 96% of patients, epirubicin was administered at 83.1% of the planned dose intensity. The median fall in left ventricular ejection fraction was 10%; clinical cardiac toxicity was observed in 3 patients. Objective responses were observed in 21 patients, including 6 complete responses.

CONCLUSIONS

High dose epirubicin was found to result in substantial hematologic toxicity but was highly active in the treatment of patients with advanced breast carcinoma.

Further evaluation of intensified and increased total dose of cyclophosphamide for the treatment of primary breast cancer: findings from National Surgical Adjuvant Breast and Bowel Project B-25

PURPOSE

In 1989, the National Surgical Adjuvant Breast and Bowel Project initiated the B-22 trial to determine whether intensifying or intensifying and increasing the total dose of cyclophosphamide in a doxorubicin-cyclophosphamide combination would benefit women with primary breast cancer and positive axillary nodes. B-25 was initiated to determine whether further intensifying and increasing the cyclophosphamide dose would yield more favorable results.

PATIENTS AND METHODS

Patients (n = 2,548) were randomly assigned to three groups. The dose and intensity of doxorubicin were similar in all groups. Group 1 received four courses, ie, double the dose and intensity of cyclophosphamide given in the B-22 standard therapy group; group 2 received the same dose of cyclophosphamide as in group 1, administered in two courses (intensified); group 3 received double the dose of cyclophosphamide (intensified and increased) given in group 1. All patients received recombinant human granulocyte colony-stimulating factor. Life-table estimates were used to determine disease-free survival (DFS) and overall survival.

RESULTS

No significant difference was observed in DFS (P =.20), distant DFS (P =.31), or survival (P =.76) among the three groups. At 5 years, the DFS in groups 1 and 2 (61% v 64%, respectively; P =. 29) was similar to but slightly lower than that in group 3 (61% v 66%, respectively; P = 08). Survival in group 1 was concordant with that in groups 2 (78% v 77%, respectively; P =.71) and 3 (78% v 79%, respectively; P =.86). Grade 4 toxicity was 20%, 34%, and 49% in groups 1, 2, and 3, respectively. Severe infection and septic episodes increased in group 3. The decrease in the amount and intensity of cyclophosphamide and delays in therapy were greatest in courses 3 and 4 in group 3. The incidence of acute myeloid leukemia increased in all groups.

CONCLUSION

Because intensifying and increasing cyclophosphamide two or four times that given in standard clinical practice did not substantively improve outcome, such therapy should be reserved for the clinical trial setting.

High-dose chemotherapy: is it standard management for any common solid tumor?

High-dose chemotherapy with stem-cell support had as its basis the observation of dose-response relationships for many chemotherapeutic agents in laboratory models. The rationale to explore high-dose treatment in the clinic was further enhanced by several retrospective reviews in the 1980s which suggested delivered dose intensity of treatment was an important determinant of patient outcome. The availability of hematopoietic growth factors and technologic advances in the efficiency of stem-cell collection and administration have made the evaluation of exploring high-dose therapy safe and feasible. However, real questions remain regarding the apparently superior results of this treatment in the management of solid tumors. This paper reviews the results of high-dose chemotherapy in breast, ovarian and small cell lung cancers. Firstly the evidence for a dose-response relationship to chemotherapeutic agents in the 'standard' dosage range is examined. Secondly results of non-randomized and, where available, randomized trials of high-dose chemotherapy (HDCT) with stem-cell support are summarized and finally conclusions regarding the weight of the evidence for use of HDCT as 'standard' treatment are given. In none of these tumors is there sufficient evidence from randomized trials to consider HDCT a standard to be offered to all patients with a given stage of disease. The apparent benefit of HDCT seen in phase II trials could well be explained by such phenomena as stage shifts and patient selection. Many randomized trials in ovary and breast cancer are either ongoing or presented only as abstracts so final results must be awaited to quantify the benefit, if any of HDCT. It is acknowledged, however, that some practitioners already utilize this treatment. We speculate about the differences in philosophical approaches to cancer treatment which might contribute to early acceptance of novel therapies in the absence of adequate randomized data.

Metastatic breast cancer

The unfortunate reality of metastatic breast cancer is that all treatment is palliative in nature. This is a disease that currently has no cure and for which therapy is directed towards accentuating survival and relieving symptoms. Current technology allows the prediction and detection of metastases earlier and with greater accuracy. These achievements need to be consolidated by the discovery of innovative therapies that can alter the inevitable outcome of this disease.

High-dose epirubicin and cyclophosphamide every two weeks as first-line chemotherapy for relapsing metastatic breast cancer patients

BACKGROUND

Metastatic breast cancer remains incurable with conventional chemotherapy. For any specific chemotherapy, higher dose intensity may be achieved with either increased doses per cycle, or shortened intervals between courses, or both. We demonstrate here the feasibility and encouraging results of a high-dose combination regimen administered every two weeks.

PATIENTS AND METHODS

Women with metastatic breast cancer were treated every 14 days for 6 courses with 75 mg/m2 epirubicin and 1200 mg/m2 cyclophosphamide, followed by conventionally-delivered (q 3-4 weeks) chemotherapy. The treatment was to be resumed regardless of the neutrophil count, except in instances of febrile neutropenia. Prophylactic oral antibiotherapy was given, while hematopoietic growth factors and stem cell support were not employed.

RESULTS

Eighty-six patients were treated between May 1986 and June 1995. Their median age was 43 years (26-69). Grade 3-4 neutrophil toxicity was observed after 86% of the courses, resulting in febrile neutropenia in 5%-18% of the patients, and the rehospitalization of 5%-10%. The median given/planned dose intensity was 97% (79-106). The objective response rate in 84 evaluable patients was 54% (95% confidence interval (95% CI): 43-65), with a complete response rate of 11%, and a 14% rate of outright progression. Median progression-free survival was 16 months and median overall survival 32 months. Multivariate analysis retained previous adjuvant chemotherapy as a negative survival prognostic factor.

CONCLUSIONS

This dose-intensive anthracycline-based regimen is feasible with manageable morbidity despite pronounced myelotoxicity, and yields encouraging survival rates.

5-year results of dose-intensive sequential adjuvant chemotherapy for women with high-risk node-positive breast cancer: A phase II study

PURPOSE

We conducted a phase II pilot study of dose-intensive adjuvant chemotherapy with doxorubicin followed sequentially by high-dose cyclophosphamide to determine the safety and feasibility of this dose-dense treatment and to estimate the disease-free and overall survival in breast cancer patients with four or more involved axillary lymph nodes.

PATIENTS AND METHODS

Seventy-three patients received adjuvant treatment with four cycles of doxorubicin 75 mg/m(2) as an intravenous bolus every 21 days, followed by three cycles of cyclophosphamide 3,000 mg/m(2) every 14 days with granulocyte colony-stimulating factor support.

RESULTS

Seventy-one patients were assessable, and all but two completed all planned chemotherapy. There was no treatment-related mortality. The most common toxicity was neutropenic fever, which occurred in 39% of patients. Median disease-free survival is 66 months (95% confidence interval, 34 to 98 months), and median overall survival has not yet been reached. At 5 years of follow-up, the disease-free survival is 51.7%, and overall survival is 60.0%. There is no long-term treatment-related toxicity, and no cases of acute myelogenous leukemia or myelodysplastic syndrome have been observed.

CONCLUSION

Our pilot study of doxorubicin followed by cyclophosphamide demonstrates the safety and feasibility of the sequential dose-dense plan. Long-term follow-up, although noncomparative, is promising. However, this regimen is associated with a higher incidence of toxicity (and also higher costs) than the standard dose and schedule of doxorubicin and cyclophosphamide, and therefore it should not be used as conventional therapy in the absence of demonstrated improvement of outcome. Randomized trials testing the dose-dense approach have been completed but not yet reported. Because the sequential plan can decrease overlapping toxicities, it is an appropriate platform for the addition of newer active agents, such as taxanes or monoclonal antibodies.

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.

Dose-response effect of adjuvant cyclophosphamide, methotrexate, 5-fluorouracil (CMF) in node-positive breast cancer. International Breast Cancer Study Group

There is evidence in the literature of a relationship between dose and response to adjuvant chemotherapy for breast cancer, although published results are conflicting. We therefore retrospectively analysed the role of dose response in patients included in four adjuvant trials of the International Breast Cancer Study Group (IBCSG, formerly the Ludwig Breast Cancer Study Group (trials I, II, III and V), all using 'classical' cyclophosphamide, methotrexate, and 5-fluorouracil (CMF). A total of 1385 node-positive patients were treated with oral cyclophosphamide, and intravenous methotrexate plus 5-fluorouracil (CMF) for at least six 4 week courses. 1350 of these were included in 6 month landmark treatment outcome analyses. A total of 1029 patients were premenopausal, 321 were postmenopausal; 800 had one to three and 550 more than three involved axillary nodes at surgery. The median follow-up ranged from 12 years for trial V to 15 years for trials I-III. Patients were grouped according to three prospectively defined dose levels based on the percentage of the protocol prescribed dose that was actually administered (level I > or = 85%, level II 65-84%, level III < 65%). Patients who received dose level II had a higher disease-free (P = 0.07) and overall survival (P = 0.03) than those who received a higher (level I) or lower (level III) percentage. The 10 year overall survival was 60% for dose level II, 56% for dose level I, 51% for dose level III. The results were generally consistent within trial, menopausal status, and oestrogen receptor status groups. The results within nodal groups showed a large difference among the dose levels for the group with one to three positive nodes (P = 0.02), but no difference for the group with four or more positive nodes. Our results indicate that the dose-response effect remains a crucial factor in adjuvant chemotherapy of breast cancer. Reductions larger than 35% in the dose administered of oral CMF adversely influenced the outcome of breast cancer patients and should be avoided. The better outcome of the intermediate dose group indicates the need to investigate other aspects involved in the cytotoxicity of adjuvant CMF chemotherapy.