High-dose carboplatin, thiotepa and cyclophosphamide (CTC) with peripheral blood stem cell support in the adjuvant therapy of high-risk breast cancer: a practical approach

High-dose chemotherapy: how resistant is breast cancer?

This report reviews clinical experience with high-dose chemotherapy with stem-cell support in breast cancer and attempts to integrate clinical and molecular biological observations into a model of drug resistance. Despite the remarkable initial chemosensitivity of breast cancer, the majority of patients with advanced breast cancer die of their disease. In trials to date, high-dose chemotherapy has not been able to overcome primary drug resistance and patients with disease progression during induction therapy benefit little from further high-dose therapy. On the other hand, high-dose chemotherapy produces improved objective response rates compared with standard-dose chemotherapy due to converting some partial responses achieved by standard-dose induction therapy to complete response. This suggests that high-dose chemotherapy may overcome partial clinical drug resistance and may result in a more complete elimination of chemosensitive cells. Whether increased complete response rates will translate into higher cure rates and increased overall survival remains to be unequivocally demonstrated. There are multiple clinical patterns of drug failure including continued growth during chemotherapy, partial response followed by a period of stable disease, initial complete response with subsequent recurrence within a few months or after several years. Different mechanisms of drug resistance may operate at different stages of the disease and predispose patients to different clinical patterns of failure. A model of clonal progression of cancer is proposed that could explain several intriguing features of clinical drug resistance. We hypothesize that drug-sensitivity is an acquired characteristic of neoplastic cells and that a 'physiological drug-resistant' state may precede drug sensitivity at early stages of neoplastic transformation. Some recurrences may, in this context, represent progression of physiologically drug-resistant clones to sensitivity and subsequently to 'pathologic resistance' to chemotherapy. Optimal therapy to delay or prevent recurrence may differ depending on the stage and biology of the tumor and may include combinations of cytotoxic drugs and chemopreventive agents to arrest progression of early physiologically drug-resistant neoplastic stem cells.

Efficacy of high-dose alkylating chemotherapy in HER2/neu-negative breast cancer

BACKGROUND

High-dose chemotherapy in the adjuvant treatment of breast cancer has been abandoned by many.

PATIENTS AND METHODS

885 patients with stage III primary breast cancer and four or more axillary lymph node metastases were randomised to receive either five courses of FEC (fluorouracil, epirubicin and cyclophosphamide) followed by radiation therapy and tamoxifen, or the same treatment but with high-dose alkylating chemotherapy (cyclophosphamide, thiotepa and carboplatin) replacing the fifth course of FEC. Of these patients, 621 had HER2/neu-negative disease, as determined by immunohistochemistry and chromogenic in situ hybridisation.

RESULTS

At a median follow-up of 84 months, a trend for a better relapse-free survival was observed in the high-dose arm: (hazard ratio (HR) 0.84, P = 0.076, two-sided). The 621 patients with HER2/neu-negative disease benefited from high-dose therapy, while patients with HER2/neu-positive disease did not (test for interaction, P = 0.006). There was a marked relapse-free survival benefit for patients with HER2/neu-negative disease (71.5% versus 59.1%, 5 years after randomisation; HR 0.68, P = 0.002) and also a survival benefit (78.2% versus 71.0% at 5 years; HR 0.72, P = 0.02).

CONCLUSIONS

The findings from this subgroup analysis provide additional evidence that HER2/neu-positive breast cancer is relatively resistant to alkylating agents. For HER2/neu-negative tumours, however, high-dose chemotherapy should remain the subject of clinical studies.

The use of high-dose cyclophosphamide, carmustine, and thiotepa plus autologous hematopoietic stem cell transplantation as consolidation therapy for high-risk primary breast cancer after primary surgery or neoadjuvant chemotherapy

We assessed the 5-year results of a high-dose cyclophosphamide, carmustine, and thiotepa (CBT) regimen plus autologous hematopoietic stem cell transplantation (AHST) as an adjuvant consolidation therapy for high-risk primary breast cancer patients with > or =10 positive axillary lymph nodes after primary surgery or > or =4 positive axillary lymph nodes after neoadjuvant chemotherapy and surgery. The associations of various potential prognostic factors with the relapse-free survival (RFS) rate and overall survival (OS) rate were determined. Between October 1992 and March 2000, 177 eligible patients (median age, 46 years) were given high-dose CBT followed by AHST. At a median follow-up of 63 months, the acute treatment-related mortality was 4.5%. Estimated 5-year RFS and OS rates were 62% and 68%, respectively, for all patients. For patients with > or =10 positive axillary lymph nodes after primary surgery, the 5-year RFS and OS rates were 71% and 70%, respectively, and for patients with > or =4 positive axillary lymph nodes after neoadjuvant chemotherapy, the 5-year RFS and OS rates were 53% and 66%, respectively. In 2-sided log-rank tests, earlier disease stage, a lower lymph node ratio, and a lower tumor score were associated with a prolonged RFS and OS. In a multivariate proportional hazards model, disease stage and lymph node ratio remained significant. We concluded that high-dose CBT with AHST for high-risk primary breast cancer is feasible, with comparable efficacy to other phase II studies. More than a 50% estimated 5-year survival rate was seen in all high-risk primary breast cancer patients. In accordance with results from recent randomized studies, we need to continue high-dose chemotherapy with AHST for patients with high-risk primary breast cancer in the phase III randomized setting.

High-dose chemotherapy with hematopoietic stem-cell rescue for high-risk breast cancer

BACKGROUND

The use of high-dose adjuvant chemotherapy for high-risk primary breast cancer is controversial. We studied its efficacy in patients with 4 to 9 or 10 or more tumor-positive axillary lymph nodes.

METHODS

Patients younger than 56 years of age who had undergone surgery for breast cancer and who had no distant metastases were eligible if they had at least four tumor-positive axillary lymph nodes. Patients in the conventional-dose group received fluorouracil, epirubicin, and cyclophosphamide (FEC) every three weeks for five courses, followed by radiotherapy and tamoxifen. The high-dose treatment was identical, except that high-dose chemotherapy (6 g of cyclophosphamide per square meter of body-surface area, 480 mg of thiotepa per square meter, and 1600 mg of carboplatin per square meter) with autologous peripheral-blood hematopoietic progenitor-cell transplantation replaced the fifth course of FEC.

RESULTS

Of the 885 patients, 442 were assigned to the high-dose group and 443 to the conventional-dose group. After a median follow-up of 57 months, the actuarial 5-year relapse-free survival rates were 59 percent in the conventional-dose group and 65 percent in the high-dose group (hazard ratio for relapse in the high-dose group, 0.83; 95 percent confidence interval, 0.66 to 1.03; P=0.09). In the group with 10 or more positive nodes, the relapse-free survival rates were 51 percent in the conventional-dose group and 61 percent in the high-dose group (P=0.05 by the log-rank test; hazard ratio for relapse, 0.71; 95 percent confidence interval, 0.50 to 1.00).

CONCLUSIONS

High-dose alkylating therapy improves relapse-free survival among patients with stage II or III breast cancer and 10 or more positive axillary lymph nodes. This benefit may be confined to patients with HER-2/neu-negative tumors.

Toxicity of the high-dose chemotherapy CTC regimen (cyclophosphamide, thiotepa, carboplatin): the Netherlands Cancer Institute experience

High-dose chemotherapy (HD-CT) has a role in the potentially curative treatment of several tumours. The relative efficacies of the different regimens have not been studied in comparative trials, but it is clear that toxicities differ significantly between them. We analysed the immediate and long-term toxicity in the first 100 consecutive patients treated with the CTC regimen (cyclophosphamide 6000 mg m(-2), carboplatin 1600 mg m(-2) (or 20 mg ml(-1) min under the curve (AUC)) both as daily 1 h infusion, thiotepa 480 mg m(-2) as twice daily 30 min infusion, all divided over 4 consecutive days) followed by peripheral blood progenitor cell reinfusion (PBPC-Tx). Most patients had high-risk (n=86) or metastatic (n=4) breast cancer, or a germ cell tumour (n=8). Two patients (with a medulloblastoma and an aesthesioneuroblastoma, respectively) received CTC as off-protocol salvage regimen. The main toxicity was bone marrow suppression. Most patients had PBPC-Tx with granulocyte colony-stimulating factor (G-CSF), and the median time to neutrophil count 500 x 10(6) l(-1) and platelet count >20 x 10(9) l(-1) without transfusion independence was 10 (range 8-25) and 13 (8-60) days, respectively. The toxic death rate was 1%. Other frequent toxicities were neutropenic fever requiring antibiotics (n=65), central catheter-related infection (n=12) or a bleeding episode (n=48), mostly epistaxis (n=26). Reversible cardiac toxicity was seen in six patients and pulmonary events occurred in seven patients (infection (n=6), embolism (n=1)). Grade 3-4 gastrointestinal toxicity was frequent: nausea and vomiting 55%, diarrhoea 28% and mild liver toxicity (transaminase elevations) 9%. One patient pretreated with cisplatin had a kidney transplantation 8 years after HD-CT. Late complications included reversible radiation pneumonitis (n=12) and chronic heart failure (n=2). We found five second solid malignancies and two myelodysplasias. In conclusion, the CTC regimen is associated with a moderate, mainly reversible, toxicity. Future studies need to compare the efficacy and toxicity of the different HD-CT regimens.

Randomized trial of high-dose chemotherapy and hematopoietic progenitor-cell support in operable breast cancer with extensive lymph node involvement: final analysis with 7 years of follow-up

BACKGROUND

The aim of this study was to present an update of overall (OS) and disease-free survival (DFS) and to evaluate the correlation between outcome and pathological findings at surgery in a randomized trial of high-dose chemotherapy following neoadjuvant chemotherapy and surgery in high-risk breast cancer patients.

PATIENTS AND METHODS

Ninety-seven women <60 years of age with breast cancer and extensive axillary lymph node involvement received three courses of FE120C (5-fluorouracil 500 mg/m2, epirubicin 120 mg/m2, cyclophosphamide 500 mg/m2) followed by surgery. Eighty-one patients were randomized to receive either a fourth FE120C course alone or a fourth FE120C course followed by high-dose chemotherapy (cyclophosphamide 6 g/m2, thiotepa 480 mg/m2, carboplatin 1600 mg/m2). We performed a univariate analysis on possible prognostic factors and analyzed the sites of relapse.

RESULTS

After a median follow-up of 6.9 years, 47 (48%) patients were alive, of whom 36 (38%) were without disease. Sixty patients relapsed after treatment. One patient died of myelodysplastic syndrome, without a relapse. In intention-to-treat analysis, the 5-year DFS rates were 47.5% in the conventional treatment arm and 49% in the high-dose arm, and the 5-year OS rates were 62.5% and 61%, respectively. In the univariate analysis, the clinical T-stage before chemotherapy and the number of tumor-positive axillary lymph nodes after induction chemotherapy (P = 0.027) were significant prognostic factors for OS. The same factors (both P = 0.06) plus the estrogen receptor (P = 0.08) were borderline significant factors for DFS.

CONCLUSIONS

After a median follow-up of 6.9 years there was no difference in OS or DFS rates between the two treatment groups. The number of tumor-positive axillary lymph nodes after induction chemotherapy and the clinical T-stage before chemotherapy were significant factors for OS.

Urinary excretion of thioTEPA and its metabolites in patients treated with high-dose cyclophosphamide, thioTEPA and carboplatin

The urinary excretion of N,N',N"-triethylenethiophosphoramide (thioTEPA), and its metabolites N,N',N"-triethylenephosphoramide (TEPA), N,N'-diethylene,N"-2-chloroethylphosphoramide (monochloroTEPA) and thioTEPA--mercapturate was determined in patients receiving thioTEPA as part of a high-dose combination chemotherapy regimen with cyclophosphamide and carboplatin. The thioTEPA dose was 40 or 60 mg/m(2) in short infusions, twice daily, during 4 days. Urine samples were collected after each voiding on each day of drug administration until 24--48 h after the last thioTEPA infusion. ThioTEPA, TEPA and monochloroTEPA concentrations were determined with gas chromatography and thioTEPA--mercapturate with liquid chromatography--mass spectrometry with direct sample injection. ThioTEPA was present in urine 30 min after infusion and was still excreted 18 h after the last infusion. All metabolites were detected in urine 1 h after infusion. Patients with a creatinine clearance above 140 ml/minl showed higher excretion of TEPA than patients with a creatinine clearance below 140 ml/min (12.8 versus 4.9%, p=0.01). The excretion of monochloroTEPA relative to the excreted amount of TEPA increased at lower pH values of the urine. The excretion of thioTEPA--mercapturate relative to the dose was higher in patients treated with 60 mg/m(2). Excretion of thioTEPA and monochloroTEPA both accounted for only 0.5% of the dose, while TEPA and thioTEPA--mercapturate both accounted for 11.1%.

Phase II study of a multi-course high-dose chemotherapy regimen incorporating cyclophosphamide, thiotepa, and carboplatin in stage IV breast cancer

The purpose of this study was to determine the feasibility and efficacy of multiple courses of high-dose cyclophosphamide, carboplatin and thiotepa with peripheral blood progenitor cell (PBPC) transplantation in women with advanced breast cancer. Forty-one patients with advanced hormone-refractory breast cancer were enrolled in the study. The treatment started with two courses of 5-fluorouracil 500 mg/m(2), epirubicin 120 mg/m(2) and cyclophosphamide 500 mg/m(2) (FE(120)C) followed by PBPC harvesting. The high-dose regimen consisted of three subsequent courses of 'tiny' CTC, cyclophosphamide 4000 mg/m(2), thiotepa 320 mg/m(2) and carboplatin 1060 mg/m(2) (target AUC 13.3 mg/ml/min) (tCTC) divided over 4 consecutive days. The second and third courses were scheduled to begin on day 28 after the previous transplantation. A total of 86 tCTC courses was given to 33 of the 41 enrolled patients. Major toxicities consisted of hemorrhagic cystitis (six patients), prolonged gastro-intestinal toxicity (three patients) and veno-occlusive disease (two patients). There was one therapy-related death (unknown cause). Twenty patients (49%) achieved a complete response, nine (22%) a partial response and three patients stable disease after treatment. The median follow-up of the surviving patients was 43 months (range 25-61). Six patients remain in complete remission beyond 3 years. At 4 years, the progression-free survival (PFS) and overall survival (OS) for the whole patient group were 23 and 30% with a median duration of 12 and 27 months, respectively and for FE(120)C-responsive patients 32 and 36%, respectively with a median duration of 15 and 33 months. In the patient group with a PFS > or = 18 months all patients had limited disease (metastatic disease in only one or two sites) and fewer patients had bone or liver metastases compared to the overall patient group (33% vs 51%). This report shows that three closely spaced courses of tCTC are feasible, with acceptable toxicity. Triple tCTC can achieve complete or partial remission in most patients and long-term PFS in a selected subgroup of patients who have limited metastatic disease and are responsive to conventional-dose chemotherapy.

Prognostic significance of the immunocytochemical detection of contaminating tumor cells (CTC) in apheresis products of patients with high-risk breast cancer treated with high-dose chemotherapy and stem cell transplantation

The aim of this study was to determine whether the detection of CTC in the apheresis product contribute significantly to treatment failure of patients with high-risk breast carcinoma treated with high-dose chemotherapy (HDC) and stem cell transplantation (SCT). Patients were with stage II and III adenocarcinoma of the breast with > or = 10 axillary lymph nodes affected after primary surgery (> or = 10 N+) who had received HDC with SCT. We analyzed retrospectively the presence of CTC as assessed by immunocytochemistry (ICC) in the apheresis products obtained after standard adjuvant chemotherapy. We compared the clinical outcome of patients who received HDC and SCT with or without CTC-positive apheresis. One hundred and twenty-seven apheresis products samples were obtained from 51 patients. Fourteen (27.4%) of these samples were CTC positive. After a median follow-up of 4.6 years, 20 patients have relapsed, 14 died from progression of their disease and 30 patients remain alive and free of progression. For the whole group of patients the 5 year probabilities of DFS and OS were 60% (IC 95%, 47-75%) and 71% (IC 95%, 55-83%), respectively. However, the 5 year probabilities of DFS were 23% (IC 95%, 0-46) and 75% (IC 95%, 60-89) for patients with CTC positive and negative, respectively. The 5 year probabilities of OS were 42% (IC 95%, 15-68) and 83% (IC 95%, 70-95) for patients with CTC positive and negative, respectively. Both univariate and multivariate analysis showed that the presence of CTC in the apheresis product was the only prognostic factor associated with a higher incidence of clinically overt disease relapse (P = 0.002) and shorter survival (P = 0.003). The presence of cytokeratin-positive metastatic cells in the apheresis product increases the risk of relapse after HDC and SCT in patients with stage II and III adenocarcinoma of the breast with > or = 10 N+.

Chemistry, pharmacology and pharmacokinetics of N,N',N" -triethylenethiophosphoramide (ThioTEPA)

N,N',N" -triethylenethiophosphoramide (thioTEPA) is a trifunctional alkylating agent with a broad spectrum of antitumour activity developed in the 1950s. The drug is now experiencing renewed interest as it appears to be one of the most effective anticancer drugs in high dose regimens. Despite many years of experience with thioTEPA, pharmacologic data are incomplete and controversy remains with respect to the dose-dependent pharmacokinetics of thioTEPA. In recent years greater insight has been obtained into the metabolism of thioTEPA, but there is still a gap between the total urinary excretion of thioTEPA and metabolites and the alkylating activity. In vivo and in vitro studies show that alkylation of DNA by thioTEPA can follow two pathways, but it remains unclear which pathway represents the precise mechanism of action. The currently available sensitive analytical methods for thioTEPA and its metabolites can be used to elucidate the many questions that still exist even so many years after its introduction. An overview is given of the chemistry, pharmacology, clinical use and toxicity of thioTEPA as well as its pharmacokinetics and analytical methods for thioTEPA and its metabolites.

Stability of thioTEPA and its metabolites, TEPA, monochloroTEPA and thioTEPA-mercapturate, in plasma and urine

The degradation of N,N',N"-triethylenethiophosphoramide (thioTEPA) and its metabolites N,N',N"-triethylenephosphoramide (TEPA), N, N'-diethylene,N"-2-chloroethylphosphoramide (monochloroTEPA) and thioTEPA-mercapturate in plasma and urine has been investigated. ThioTEPA, TEPA and monochloroTEPA were analyzed using a gas chromatographic (GC) system with selective nitrogen/phosphorous detection; thioTEPA-mercapturate was analyzed on a liquid chromatography-mass spectrometric (LC-MS) system. The influences of pH and temperature on the stability of thioTEPA and its metabolites were studied. An increase in degradation rate was observed with decreasing pH as measured for all studied metabolites. In urine the rate of degradation at 37 degrees C was approximately 2.5+/-1 times higher than at 22 degrees C. At 37 degrees C thioTEPA and TEPA were more stable in plasma than in urine, with half lives ranging from 9-20 h for urine and 13-34 h for plasma at pH 6. Mono- and dichloro derivatives of thioTEPA were formed in urine and the monochloro derivative was found in plasma. Degradation of TEPA in plasma and urine resulted in the formation of monochloroTEPA. During the degradation of TEPA in plasma also the methoxy derivative of TEPA was formed as a consequence of the applied procedure. The monochloro derivative of thioTEPA-mercapturate was formed in urine, whereas for monochloroTEPA no degradation products could be detected.

Hematological recovery and peripheral blood progenitor cell mobilization after induction chemotherapy and GM-CSF plus G-CSF in breast cancer

In order to determine the effect of GM-CSF plus G-CSF in combination in breast cancer patients receiving an effective induction regimen, we compared hematological recovery and peripheral blood progenitor cell (PBPC) mobilization according to colony-stimulating factor (CSF) support. Forty-three breast cancer patients were treated by TNCF (THP-doxorubicin, vinorelbine, cyclophosphamide, fluorouracil, D1 to D4) with CSF support: 11 patients received GM-CSF (D5 to D14); 16 patients G-CSF (D5 to D14) and 16 patients GM-CSF (D5-D14) plus G-CSF (D10-D14). Between two subsequent cycles, progenitor cells were assessed daily, from D13 to D17. The WBC count was similar for patients receiving G-CSF alone or GM-CSF plus G-CSF, but significantly greater than that of patients receiving GM-CSF alone (P<0.001). The GM-CSF plus G-CSF combination led to better PBPC mobilization, with significantly different kinetics (P<0.001) and optimal mean values of CFU-GM, CD34+ cells and cells in cycle, at D15 compared to those obtained with G-CSF or GM-CSF alone. The significantly greater PBPC mobilization obtained with a CSF combination by D15 could be of value for PBPC collection and therapeutic reinjection after high-dose chemotherapies.

Stage III and oestrogen receptor negativity are associated with poor prognosis after adjuvant high-dose therapy in high-risk breast cancer

We report on the efficacy and toxicity of a sequential high-dose therapy with peripheral blood stem cell (PBSC) support in 85 patients with high-risk stage II/III breast cancer. There were 71 patients with more than nine tumour-positive axillary lymph nodes. An induction therapy of two cycles of ifosfamide (total dose, 7.5 g m(-2)) and epirubicin (120 mg m(-2)) was given, and PBSC were harvested during G-CSF-supported leucocyte recovery following the second cycle. The PBSC-supported high-dose chemotherapy consisted of two cycles of ifosfamide (total dose, 12,000 mg m(-2)), carboplatin (900 mg m(-2)) and epirubicin (180 mg m(-2)). Patients were autografted with a median number of 3.7 x 10(6) CD34+ cells kg(-1) (range, 1.9-26.5 x 10(6)) resulting in haematological reconstitution within approximately 2 weeks following high-dose therapy. The toxicity was moderate in general, and there was no treatment-related toxic death. Twenty-one patients relapsed between 3 and 30 months following the last cycle of high-dose therapy (median, 11 months). The probability of disease-free and overall survival at 4 years were 60% and 83%, respectively. According to a multivariate analysis, patients with stage II disease had a significantly better probability of disease-free survival (74%) in comparison to patients with stage III disease (36%). The probability of disease-free survival was also significantly better for patients with oestrogen receptor-positive tumours (70%) compared to patients with receptor-negative ones (40%). Bone marrow samples collected from 52 patients after high-dose therapy were examined to evaluate the prognostic relevance of isolated tumour cells. The proportion of patients presenting with tumour cell-positive samples did not change in comparison to that observed before high-dose therapy (65% vs 71%), but a decrease in the incidence and concentration of tumour cells was observed over time after high-dose therapy. This finding was true for patients with relapse and for those in remission, which argues against a prognostic significance of isolated tumour cells in bone marrow. In conclusion, sequential high-dose chemotherapy with PBSC support can be safely administered to patients with high-risk stage II/III breast cancer. Further intensification of the therapy, including the addition of non-cross resistant drugs or immunological approaches such as the use of antibodies against HER-2/NEU, may be envisaged for patients with stage III disease and hormone receptor-negative tumours.

Degradation study of thiotepa in aqueous solutions

The degradation of N,N',N"-triethylenethiophosphoramide (thiotepa) in aqueous solutions has been investigated over the pH range 1-14. Samples were analyzed using a high-performance liquid chromatographic system with UV detection. The degradation kinetics were studied as a function of pH, sodium chloride concentration and temperature. The degradation of thiotepa follows pseudo first order kinetics. The pH-log kobs profile shows that thiotepa is most stable in the pH range 7-11. At pH?11 chloride has no influence on the degradation rate. The degradation products were isolated and the structures identified by mass spectrometry. Chloro adducts of thiotepa are generated in the presence of sodium chloride and in acidic medium. In the pH range 7-11 only the mono-chloro adduct of thiotepa could be found. No detectable degradation products were formed at pH?11.

Randomised trial of high-dose chemotherapy and haemopoietic progenitor-cell support in operable breast cancer with extensive axillary lymph-node involvement

BACKGROUND

Uncontrolled studies suggest that high-dose chemotherapy is beneficial in patients with breast cancer and multiple metastases to the axillary lymph nodes. Many physicians accept this treatment as standard care. We aimed to assess adjuvant high-dose chemotherapy in breast cancer in a phase II randomised trial.

METHODS

97 women aged younger than 60 years, who had breast cancer with extensive axillary-node metastases (confirmed by a tumour-positive infraclavicular lymph-node biopsy), received three courses of up-front chemotherapy (FE120C). This regimen consisted of cyclophosphamide 500 mg/m2, epirubicin 120 mg/m2, and 5-fluorouracil 500 mg/m2 once weekly for 3 weeks. After surgery, stable patients or those who responded to chemotherapy were randomly assigned conventional therapy (fourth course of FE120C, followed by radiation therapy and 2 years of tamoxifen [40 patients]) or high-dose therapy (identical treatment but an additional high-dose regimen and peripheral-blood progenitor-cell [PBPC] support after the fourth FE120C course [41 patients]). This high-dose regimen comprised cyclophosphamide 6 g/m2, thiotepa 480 mg/m2, and carboplatin 1600 mg/m2. The primary endpoint was overall and disease-free survival. All analyses were by intention to treat.

FINDINGS

No patients died from toxic effects of chemotherapy. With a median follow-up of 49 (range 21-76) months, the 4-year overall and relapse-free survivals for all 97 patients were 75% and 54%, respectively. There was no significant difference in survival between the patients on conventional therapy and those on high-dose therapy.

INTERPRETATION

High-dose therapy is associated with substantial cost and acute toxic effects, but also has potentially irreversible long-term effects. Until the benefit of this therapy is substantiated by large-scale phase III trials, high-dose chemotherapy should not be used in the adjuvant treatment of breast cancer, apart from in randomised studies.

Durable remission of locally advanced breast cancer with multimodality management

We treated 20 women with locally advanced breast cancer between January 1991 and September 1996. The treatment regimen included 4 cycles of intensive doxorubicin (30 mg/m2/d on 3 consecutive days every 2 weeks with G-CSF support), followed by appropriate surgery, followed by high dose therapy with cyclophosphamide, carboplatin and thiotepa (STAMP V, CTCb). Of the 20 patients, seven presented with inflammatory breast cancer, three with Stage IIIB, seven with stage IIIA, one with multifocal Stage IIB and two with Stage IV M1 (ipsilateral supraclavicular lymph node involvement) (including one who had an inflammatory primary) disease. Six patients had not undergone mastectomy at the time of entering the protocol. These six received the doxorubicin in a neoadjuvant fashion and were thus evaluable for tumor response. The remaining 14 received doxorubicin as adjuvant therapy prior to intensification and transplantation. All patients underwent local-regional radiation therapy and were placed on oral tamoxifen. Doxorubicin was well tolerated in this schedule with all but three patients receiving all their cycles on schedule. Both BM and PBPC were easily collected after this regimen and, when reinfused, resulted in the prompt recovery of granulocytes (median 11 days to 500 absolute granulocyte count) and platelets (median 13 days to 20,000 platelets). The six patients who received doxorubicin prior to mastectomy all had major clinical responses, but were found to have microscopic focii of breast cancer in the mastectomy specimens. The overall treatment was well tolerated with the exception of one treatment-related death (5%). The overall and relapse free survival are 70% and 58% respectively with a median follow-up of 40 months (range 12-74 months). When the Stage IV patients are censored, the relapse-free survival rate is 69%. In the bone marrow transplant phase of treatment, the major non-hematologic toxicities were stomatitis (70%) and anorexia requiring parental nutrition (75%).

Impairment of cognitive function in women receiving adjuvant treatment for high-risk breast cancer: high-dose versus standard-dose chemotherapy

BACKGROUND

Although high-dose chemotherapy is rapidly gaining acceptance as a treatment option for a number of cancers, the long-term toxic effects of such therapy are a concern. Cognitive deficits (e.g., problems with memory and concentration) are not uncommon after chemotherapy, but they have not been documented systematically. In this study, we assessed the prevalence of cognitive deficits in a group of patients with high-risk breast cancer who were randomly assigned to receive either high-dose or standard-dose adjuvant chemotherapy plus tamoxifen, and we investigated whether high-dose chemotherapy impaired cognitive functioning more than standard-dose chemotherapy.

METHODS

Cognitive functioning was evaluated by use of a battery of neuropsychologic tests. In addition, patients were interviewed with regard to cognitive problems, health-related quality of life, anxiety, and depression. Results from patients who received adjuvant systemic therapy were compared with results from patients who had early stage breast cancer not treated with such therapy (control patients).

RESULTS

The study population consisted of 34 patients treated with high-dose chemotherapy plus tamoxifen, 36 patients treated with standard-dose chemotherapy plus tamoxifen, and 34 control patients. For all patients, the average time since the completion of last nonhormonal therapy was 2 years. Cognitive impairment was found in 32% of the patients treated with high-dose chemotherapy, in 17% of the patients treated with standard-dose chemotherapy, and in 9% of the control patients. In comparison with the control patients, patients treated with high-dose chemotherapy appeared to have an 8.2-times higher risk of cognitive impairment (odds ratio; 95% confidence interval [CI] = 1.8-37.7); in comparison with the patients who received standard-dose chemotherapy, this risk of impairment was 3.5-times higher (95% CI = 1.0-12.8).

CONCLUSION

High-dose chemotherapy appears to impair cognitive functioning more than standard-dose chemotherapy. Central nervous system toxicity may be a dose-limiting factor in high-dose chemotherapy regimens.

A comparative review of colony-stimulating factors

The efficacy of dose-intensive chemotherapy in oncology is limited by the duration and severity of neutropenia. Several recombinant DNA factors that alter neutrophil proliferation and function, and are characterised by their ability to stimulate colony formation of myeloid progenitors in vitro, have been shown to alter clinical sequelae associated with neutropenia in vivo. Two of these factors, granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF), have been approved by the US FDA. One other factor, macrophage colony-stimulating factor (M-CSF), is approved as indicated therapy in Japan. The clinical effects of these agents are compared in this review. Results of clinical trials suggest that the efficacy of G-CSF is greatest when used as an agent to enhance circulation of stem cells and pre-colony-forming progenitor cells. It is also an effective agent in reducing the duration of neutropenia following dose-intensive chemotherapy, thereby leading to a reduction in the incidence of febrile neutropenia. Similar observations were made with GM-CSF, although toxicity with the latter agent appears to be moderately greater than that observed with G-CSF. Functional activity of GM-CSF is broader than that of G-CSF, in that macrophages are affected by GM-CSF. As a result, some data suggest that GM-CSF may be more applicable to patients with a high risk of infection. There is a suggestion that M-CSF assists neutrophil recovery, although this effect may be indirect, via the induction of other cytokines. The predominant effect of M-CSF appears to be enhancement of macrophage and monocyte function, which may reduce the severity and duration of fungal infection.

Epirubicin. An updated review of its pharmacodynamic and pharmacokinetic properties and therapeutic efficacy in the management of breast cancer

Epirubicin, an anthracycline antitumour antibiotic which is structurally related to doxorubicin, is among the most active single agents used in the management of patients with breast cancer. The drug may be administered alone or in combination with other agents both to patients with early breast cancer and to those with metastatic disease. There is a clear relationship between epirubicin dose and tumour response. Dose intensified regimens have produced improved response rates in patients with advanced breast cancer compared with standard dose therapy; however, improved overall survival has not yet been demonstrated. The combination of epirubicin with newer agents such as vinorelbine or paclitaxel shows considerable promise, as does the use of epirubicin in high dose regimens with peripheral blood progenitor cell support. The major adverse effects of epirubicin are acute dose-limiting haematological toxicity and cumulative dose-related cardiac toxicity. These effects are less severe after epirubicin administration than after equimolar doses of doxorubicin. Other major adverse effects of epirubicin administration include mucositis, nausea and vomiting, reversible alopecia and local cutaneous and vesicant reactions. In summary, epirubicin has an established role in the treatment of both early and advanced breast cancer. Incombination with other highly active agents or in dose intensified regimens administered with haemopoietic growth factor and/or peripheral blood progenitor cell support, epirubicin may play a significant role in emerging breast cancer treatment strategies.

Harvest quality and factors affecting collection and engraftment of CD34+ cells in patients with breast cancer scheduled for high-dose chemotherapy and peripheral blood progenitor cell support

The use of CFU-GM and CD34+ cell enumeration for assessing harvest quality and factors affecting peripheral blood progenitor cell (PBPC) harvest and engraftment were investigated in 45 women with high-risk and metastatic breast cancer scheduled for dose-intensive cyclophosphamide, thiotepa, and carboplatin (CTCb). PBPC were mobilized with standard breast cancer regimens or cyclophosphamide (1.5 g/m2) and 5 micrograms/kg/day G-CSF and used together with G-CSF for hematopoietic support post-CTCb. There was a significant correlation between peripheral blood CD34+ cells/microliter and harvest CD34+/kg (r = 0.73, p < 0.0001) and between harvest CFU-GM and CD34+ cells/kg (r = 0.5, p < 0.0001). CFU-GM clonogenic assays were of no clinical use beyond that of CD34+ cell enumeration, with the latter allowing for real-time decisions regarding harvesting. Multiple stepwise regression identified the number of prior chemotherapy cycles as the only significant clinical predictor of CD34+ cell yield. For 34 patients proceeding to CTCb with PBPC support, multiple stepwise regression identified as the best predictors for engraftment CFU-GM and CD34+ cells/kg for neutrophils and CFU-GM, CD34+ cells/kg, and the number of prior cycles of chemotherapy for platelets, respectively. A threshold dose of 1 x 10(6) CD34+ cells/kg, obtained in 87% of these heavily pretreated breast cancer patients, was adequate to ensure engraftment within 15 days. There was no significant difference in length of hospital stay or blood product use between patients receiving 1-2.5 x 10(6) CD34+ cells/kg and greater than 2.5 x 10(6) CD34+ cells/kg, although median time to engraftment of neutrophils (9 days versus 8 days, p = 0.007) and platelets (12 days versus 9 days, p = 0.006) was significantly longer. The established threshold of > or = 1 x 10(6) CD34+ cells/kg will allow for more confident consideration of using aliquots of this threshold dose for hematopoietic support in sequential high-dose regimens inclusive of CTCb.

High-dose carboplatin, etoposide and melphalan (CEM) with peripheral blood progenitor cell support as late intensification for high-risk cancer: non-haematological, haematological toxicities and role of growth factor administration

The present report describes the non-haematological toxicity and the influence of growth factor administration on haematological toxicity and haematopoietic recovery observed after high-dose carboplatin (1200 mg m(-2)), etoposide (900 mg m(-2)) and melphalan (100 mg m(-2)) (CEM) followed by peripheral blood progenitor cell transplantation (PBPCT) in 40 patients with high-risk cancer during their first-line treatment. PBPCs were collected during the previous outpatient induction chemotherapy programme by leukaphereses. CEM administration with PBPCT was associated with low non-haematological toxicity and the only significant toxicity consisted of a reversible grade III/IV increase in liver enzymes in 32% of the patients. Haematopoietic recovery was very fast in all patients and the administration of granulocyte colony-stimulating factor (G-CSF) plus erythropoietin (EPO) or granulocyte-macrophage colony-stimulating factor (GM-CSF) plus EPO after PBPCT significantly reduced haematological toxicity, abrogated antibiotic administration during neutropenia and significantly reduced hospital stay and patient's hospital charge compared with patients treated with PBPCT only. None of the patients died early of CEM plus PBPCT-related complications. Low non-haematological toxicity and accelerated haematopoietic recovery renders CEM with PBPC/growth factor support an acceptable therapeutic approach in an adjuvant or neoadjuvant setting.

High-dose chemotherapy supported by peripheral blood progenitor cells in poor prognosis metastatic breast cancer--phase I/II study. Edinburgh Breast Group

Current treatments for metastatic breast cancer are not associated with significant survival benefits despite response rates of over 50%. High-dose therapy with autologous bone marrow transplantation (ABMT) has been investigated, particularly in North America, and prolonged survival in up to 25% of women has been reported, but with a significant treatment-related mortality. However, in patients with haematological malignancies undergoing autologous transplantation, haematopoietic reconstruction is significantly quicker and mortality lower than with ABMT, when peripheral blood progenitor cells (PBPCs) are used. In 32 women with metastatic breast cancer, we investigated the feasibility of PBPC mobilisation with high-dose cyclophosphamide and granulocyte colony-stimulating factor (G-CSF) after 12 weeks' infusional induction chemotherapy and the subsequent efficacy of the haematopoietic reconstitution after conditioning with melphalan and either etoposide or thiotepa. PBPC mobilisation was successful in 28/32 (88%) patients, and there was a rapid post-transplantation haematopoietic recovery: median time to neutrophils > 0.5 x 10(9) l-1 was 14 days and to platelets > 20 x 10(9) l-1 was 10 days. There was no procedure-related mortality, and the major morbidity was mucositis (WHO grade 3-4) in 18/32 patients (56%). In a patient group of which the majority had very poor prognostic features, the median survival from start of induction chemotherapy was 15 months. Thus, PBPC mobilisation and support of high-dose chemotherapy is feasible after infusional induction chemotherapy for patients with metastatic breast cancer, although the optimum drug combination has not yet been determined.

The toxicity of radiotherapy following high-dose chemotherapy with peripheral blood stem cell support in high-risk breast cancer: a preliminary analysis

High-dose chemotherapy with autologous bone marrow and/or peripheral blood stem cell (PBSC) support is increasingly employed in the adjuvant treatment of high-risk breast cancer. Subsequent radiotherapy has been reported to be associated with morbidity and mortality resulting from pulmonary toxicity. In addition, the course of radiation therapy may be hampered by excess myelosuppression. The aim of this study was to investigate the contribution to radiation-induced toxicity of a high-dose chemotherapy regimen (CTC) that incorporates cyclophosphamide, thiotepa and carboplatin, in patients with high-risk breast cancer. In two randomised single institution studies, 70 consecutive patients received anthracycline-containing adjuvant chemotherapy (FEC: 5-fluorouracil, epirubicin and cyclophosphamide) followed by radiotherapy to achieve maximal local control. Of these patients, 34 received high-dose CTC with autologous PBSC support. All patients tolerated the full radiation dose in the planned time schedule. Radiation pneumonitis was observed in 5 patients (7%), 4 of whom had undergone high-dose chemotherapy (P = 0.38). All 5 responded favourably to prednisone. Fatal toxicities were not observed. Myelosuppression did not require interruption or untimely discontinuation of the radiotherapy, although significant reductions in median nadir platelet counts and haemoglobin levels were observed in patients who had received high-dose chemotherapy (P = 0.0001). The median nadir of WBC counts was mildly but significantly decreased during radiotherapy (P = 0.01). Red blood cell or platelet transfusions were rarely indicated. Adequate radiotherapy for breast cancer can be safely administered after high-dose CTC with autologous PBSC support. Radiation-induced myelotoxicity is clearly enhanced following CTC, but this is of little clinical significance. Radiation pneumonitis after high-dose therapy may occur more often in patients with a history of lung disease or after a relatively high radiation dose to the chest wall. Other high-dose regimens, particularly those incorporating drugs with known pulmonary toxicity (such as BCNU), may predispose patients to radiation pneumonitis.

Efficacy of up-front 5-fluorouracil-epidoxorubicin-cyclophosphamide (FEC) chemotherapy with an increased dose of epidoxorubicin in high-risk breast cancer patients

The prognosis of patients with stage IIIB breast carcinoma with tumour spread to the apical axillary lymph nodes has hardly improved despite adequate locoregional control and the introduction of systemic adjuvant therapy. A combined modality regimen that includes anthracyclin-based chemotherapy, high-dose chemotherapy with peripheral stem cell support and radiation and hormonal therapy is currently under investigation in this subset of patients. The present study aims to document the efficacy and feasibility of dose-intensive epidoxorubicin in combination with a standard dose of 5-fluorouracil and cyclophosphamide as up-front chemotherapy in this setting. A preoperative chemotherapy regimen consisting of three courses of 5-fluorouracil 500 mg m-2, epidoxorubicin 120 mg m-2 and cyclophosphamide 500 mg m-2 (FE120C) was administered at 21 day intervals without haematopoietic growth factors to 70 patients with apex node-positive disease. All patients were below 60 years of age and had not had prior chemotherapy or radiotherapy. Sixty-six patients were evaluable for clinical response and histopathological examination could be performed in 62 of these. Thirteen patients achieved a clinical complete response (20%). Of these patients, microscopic examination of the mastectomy specimen revealed absence of malignant cells in two and exclusively ductal carcinoma in situ (DCIS) in another two patients. In addition, of the 46 patients (70%) with a clinical partial response, at pathological examination one patient had sclerosis only and four had DCIS. This results in a pathological complete response in three (5%) of all patients and absence of invasive carcinoma in 10%. None of the patients progressed during chemotherapy. The major toxicity was moderate bone marrow suppression with a median white blood count (WBC) nadir of 1800 microliters-1 (range 500-4900). Other toxicities were mild. The full planned dose could be given without delays in 66 of 70 patients FE120C is well tolerated and is highly effective as up-front chemotherapy in relatively young patients with high-risk breast cancer, with a 90% (CI 74-98%) clinical objective response rate.

Pharmacokinetics and pharmacodynamics of carboplatin administered in a high-dose combination regimen with thiotepa, cyclophosphamide and peripheral stem cell support

The aim of this pharmacokinetic/pharmacodynamic study was to define the relationships of the carboplatin exposure with the toxicity in patients treated with high dose carboplatin (400 mg m-2 day-1), cyclophosphamide (1500 mg m-2 day-1) and thiotepa (120 mg m-2 day-1) for four consecutive days, followed by peripheral stem cell transplantation. Exposure to carboplatin was studied in 200 treatment days by measuring the area under the carboplatin plasma ultrafiltrate (pUF) concentration vs time curve (AUC). The AUC was obtained by using a previously validated limited sampling model. A total of 31 patients was studied who received one, two or three courses of this high-dose chemotherapy regimen. The unbound, plasma ultrafiltrate carboplatin was almost completely cleared from the body before each next treatment day in a course; the day-to-day AUC variation was 3.3%. The mean cumulative AUC over 4 days was 19.6 (range 14.1-27.2) mg ml-1 min-1. In 97 treatment days the carboplatin dose was calculated using the Calvert formula with the creatinine clearance as the measure for the glomerular filtration rate (GFR). For these courses, the inter-patient variability in pharmacokinetics was significantly reduced from 21% to 15% (P = 0.007) in comparison with the schemes where it was given as a fixed dose of 400 mg m-2. There were no relationships found between toxicity and the AUC of carboplatin, which may be due to the influence of overlapping toxicities of cyclophosphamide and thiotepa. However, the ototoxicity was strongly related to the cumulative carboplatin AUC. This toxicity was dose limiting for carboplatin in this schedule. It appeared that the carboplatin pharmacokinetics in these regimens were similar to those reported at conventional dosages. To reduce the inter-patient variation, the carboplatin dose can be calculated using the Calvert-formula with the creatinine clearance as the measure for the GFR.

Incidence and prevention of nonhaematological toxicity of high-dose chemotherapy

The introduction of the haematopoietic growth factors (HGFs), together with the evolution of techniques to harvest haematopoietic stem cells from the peripheral blood, have greatly facilitated the use of high-dose chemotherapy (HDC). While haematological toxicity of HDC is no longer dose-limiting, damage to other tissues has become more pronounced. In fact, nonhaematological toxicity (NHTOX) is now often dose-limiting in HDC regimens. NHTOX associated with HDC regimens depends on the type and dose of the drugs used, the physical condition and the characteristics of the patients treated and the given comedication. We describe the most important toxic effects of commonly used HDC programmes, such as nausea, vomiting, and mucositis, neutropaenic fever and sepsis, various major organ toxicities, catheter-associated problems and long-term complications. In addition, we discuss the possibilities of preventing these side-effects and what action to take if they occur.

High-dose chemotherapy regimens for solid tumors

High-dose chemotherapy with blood progenitor cell transplantation is increasingly recognized as a potentially valuable treatment for breast cancer, germ cell cancer, ovarian cancer and other solid tumors. A variety of cytotoxic drugs, particularly alkylating agents, have been investigated either alone or in combinations. Current, predominantly small, phase I and phase II clinical trials to not adequately compare the efficacy of these regiments and patterns of dose-limiting extramedullary toxicity are emerging. Busulfan, carmustine (BCNU) and mitomycin C cause veno-occlusive disease (VOD) of the liver in some patients and the latter two agents also cause interstitial pneumonitis. Cisplatin and ifosfamide only allow minor dose escalation before renal failure becomes prohibitive. Cyclophosphamide, thiotepa, melphalan and etoposide allow substantial dose escalation above standard and are mainly associated with mucositis. Moderate dose escalations of mitoxantrone and carboplatin are possible, limited by cardiotoxicity and neurotoxicity, respectively. Advances in supportive care have abolished bone marrow suppression as the dose-limiting toxicity in chemotherapy. Severe and potentially fatal extramedullary toxicity following high-dose chemotherapy can only be avoided by administering agents with predictable toxicity patterns and by carefully considering their clinical pharmacology.