Prophylactic filgrastim (G-CSF) during mitomycin-C, mitoxantrone, and methotrexate (MMM) treatment for metastatic breast cancer. A randomized study

Granulocyte Colony-Stimulating Factor Restored Impaired Spermatogenesis and Fertility in an AML-Chemotherapy Mice Model

Leukemia and treatment of male patients with anticancer therapy (aggressive chemotherapy and/or radiotherapy) may lead to infertility or even permanent male sterility. Their mechanisms of spermatogenesis impairment and the decrease in male fertility are not yet clear. We showed that under acute myeloid leukemia (AML) conditions, alone and in combination with cytarabine (CYT), there was significant damage in the histology of seminiferous tubules, a significant increase in apoptotic cells of the seminiferous tubules, and a reduction in spermatogonial cells (SALL and PLZF) and in meiotic (CREM) and post-meiotic (ACROSIN) cells. In addition, we showed a significant impairment in sperm parameters and fertilization rates and offspring compared to control. Our results showed a significant decrease in the expression of glial cell line-derived neurotrophic factor (GDNF), macrophage colony-stimulating factor (MCSF) and stem cell factor (SCF) under AML conditions, but not under cytarabine treatment compared to control. In addition, our results showed a significant increase in the pro-inflammatory cytokine interleukin-1 (IL-1) alpha in whole testis homogenates in all treatment groups compared to the control. Increase in IL-1 beta level was shown under AML conditions. We identified for the first time the expression of GCSF receptor (GCSFR) in sperm cells. We showed that GCSF injection in combination with AML and cytarabine (AML + CYT + GCSF) extended the survival of mice for a week (from 6.5 weeks to 7.5 weeks) compared to (AML + CYT). Injection of GCSF to all treated groups (post hoc), showed a significant impact on mice testis weight, improved testis histology, decreased apoptosis and increased expression of pre-meiotic, meiotic and post- meiotic markers, improved sperm parameters, fertility capacity and number of offspring compared to the controls (without GCSF). GCSF significantly improved the spermatogonial niche expressed by increased the expression levels of testicular GDNF, SCF and MCSF growth factors in AML-treated mice and (AML + CYT)-treated mice compared to those groups without GCSF. Furthermore, GCSF decreased the expression levels of the pro-inflammatory cytokine IL-12, but increased the expression of IL-10 in the interstitial compartment compared to the relevant groups without GCSF. Our results show for the first time the capacity of post injection of GCSF into AML- and CYT-treated mice to improve the cellular and biomolecular mechanisms that lead to improve/restore spermatogenesis and male fertility. Thus, post injection of GCSF may assist in the development of future therapeutic strategies to preserve/restore male fertility in cancer patients, specifically in AML patients under chemotherapy treatments.

The impact of granulocyte colony-stimulating factor use in patients with metastatic breast cancer treated with palliative chemotherapy: a single-institution retrospective review

PURPOSE

The goal of chemotherapy for metastatic breast cancer (MBC) is palliation of symptoms while minimizing treatment-related toxicities. It remains unclear whether use of granulocyte colony-stimulating factor (G-CSF) to maintain relative dose intensity of chemotherapy for MBC is associated with improved clinical outcomes.

METHODS

The medical records of MBC patients treated with chemotherapy in 1st-3rd-line settings between May 2010 and April 2014 were reviewed. Time to progression (TTP), progression-free survival (PFS), and overall survival (OS) were compared between patients who received G-CSF and those who did not. Antibiotic use, total clinic visits, and pre- and post-treatment Eastern Cooperative Oncology Group (ECOG) performance status were also compared between the groups.

RESULTS

Of the 169 patients included, 55 (32.5%) received > 1 G-CSF dose and 114 (67.5%) did not receive any G-CSF. The median TTP was similar between the two groups (5.0 months (95% CI 3.4-7.1) vs. 5.2 months (95% CI 4.8-6.2) respectively; p = 0.998). The median PFS (p = 0.955; 5.0 months (95% CI 3.4-5.9) vs. 5.2 months (95% CI 4.7-6.0), respectively) and OS (14.6 (95% CI 9.0-26.6) vs. 18.5 months (95% CI 15.2-22.0) in G-CSF and non-G-CSF groups, respectively; p = 0.628) were also similar between groups. No significant between-group differences were noted in rate of decline in ECOG performance status, antibiotic use, and number of clinic visits and hospitalizations.

CONCLUSION

This retrospective analysis did not find any evidence that the use of G-CSF to maintain chemotherapy dose intensity for the treatment of MBC improves TTP, PFS, and OS or results in improved ECOG performance status compared with lack of G-CSF use in patients with MBC treated in 1st to 3rd-line settings.

Efficacy and tolerability of granulocyte colony-stimulating factors in cancer patients after chemotherapy: A systematic review and Bayesian network meta-analysis. Sci Rep. 2019;9:15374. [PMID: 31653961 PMCID: PMC6814815 DOI: 10.1038/s41598-019-51982-4]

The optimum granulocyte colony-stimulating factor (G-CSF) treatment for cancer patients after being treated with cytotoxic chemotherapy remains unknown. Therefore, a systematic review and Bayesian network meta-analysis were performed to assess the efficacy and tolerability of 11 G-CSF drugs on patients after chemotherapy. A total of 73 randomized controlled trials (RCTs) containing 15,124 cancer patients were included for the final network meta-analysis. Compared with pegfilgrastim, there were a higher risk with filgrastim for incidence of febrile neutropenia (FN) (OR [95% CI]: 1.63 [1.07, 2.46]), and a higher risk with short-acting G-CSF (S-G-CSF) biosimilar and lenograstim for incidence of bone pain (BP) (OR [95% CI]: 6.45 [1.10, 65.73], 5.12 [1.14, 26.12], respectively). Mecapegfilgrastim, lipegfilgrastim and balugrastim were best G-CSF drugs in reducing FN (cumulative probabilities: 58%, 15%, 11%, respectively). S-G-CSF biosimilar, empegfilgrastim, and long-acting G-CSF (L-G-CSF) biosimilar were best G-CSF drugs in reducing severe neutropenia (SN) (cumulative probabilities: 21%, 20%, 15%, respectively). Mecapegfilgrastim, balugrastim, lipegfilgrastim and L-G-CSF biosimilar were best G-CSF drugs in reducing BP (cumulative probabilities: 20%, 14%, 8%, 8%, respectively). Mecapegfilgrastim, lipegfilgrastim and balugrastim might be the most appreciate G-CSF drugs with both good efficacy and tolerability when treating cancer patients after cytotoxic chemotherapy.

Ovarian Follicle Depletion Induced by Chemotherapy and the Investigational Stages of Potential Fertility-Protective Treatments-A Review

Ovarian follicle pool depletion, infertility, and premature menopause are all known sequelae of cancer treatment that negatively impact the quality of life of young cancer survivors. The mechanisms involved in this undesired iatrogenic ovarian damage have been intensively studied, but many of them remain unclear. Several chemotherapeutic drugs have been shown to induce direct and indirect DNA-damage and/or cellular stress, which are often followed by apoptosis and/or autophagy. Damage to the ovarian micro-vessel network induced by chemotherapeutic agents also seems to contribute to ovarian dysfunction. Another proposed mechanism behind ovarian follicle pool depletion is the overactivation of primordial follicles from the quiescent pool; however, current experimental data are inconsistent regarding these effects. There is great interest in characterizing the mechanisms involved in ovarian damage because this might lead to the identification of potentially protective substances as possible future therapeutics. Research in this field is still at an experimental stage, and further investigations are needed to develop effective and individualized treatments for clinical application. This review provides an overview of the current knowledge and the proposed hypothesis behind chemotherapy-induced ovarian damage, as well as current knowledge on possible co-treatments that might protect the ovary and the follicles from such damages.

Predicting neutropenia risk in patients with cancer using electronic data

Objectives

Clinical guidelines recommending the use of myeloid growth factors are largely based on the prescribed chemotherapy regimen. The guidelines suggest that oncologists consider patient-specific characteristics when prescribing granulocyte-colony stimulating factor (G-CSF) prophylaxis; however, a mechanism to quantify individual patient risk is lacking. Readily available electronic health record (EHR) data can provide patient-specific information needed for individualized neutropenia risk estimation. An evidence-based, individualized neutropenia risk estimation algorithm has been developed. This study evaluated the automated extraction of EHR chemotherapy treatment data and externally validated the neutropenia risk prediction model.

Materials and Methods

A retrospective cohort of adult patients with newly diagnosed breast, colorectal, lung, lymphoid, or ovarian cancer who received the first cycle of a cytotoxic chemotherapy regimen from 2008 to 2013 were recruited from a single cancer clinic. Electronically extracted EHR chemotherapy treatment data were validated by chart review. Neutropenia risk stratification was conducted and risk model performance was assessed using calibration and discrimination.

Results

Chemotherapy treatment data electronically extracted from the EHR were verified by chart review. The neutropenia risk prediction tool classified 126 patients (57%) as being low risk for febrile neutropenia, 44 (20%) as intermediate risk, and 51 (23%) as high risk. The model was well calibrated (Hosmer-Lemeshow goodness-of-fit test = 0.24). Discrimination was adequate and slightly less than in the original internal validation (c-statistic 0.75 vs 0.81).

Conclusion

Chemotherapy treatment data were electronically extracted from the EHR successfully. The individualized neutropenia risk prediction model performed well in our retrospective external cohort.

Meta-analysis and indirect treatment comparison of lipegfilgrastim with pegfilgrastim and filgrastim for the reduction of chemotherapy-induced neutropenia-related events

Background

Granulocyte colony-stimulating factors are effective at reducing the risk and duration of neutropenia. The current meta-analysis compared the neutropenia-related efficacy and safety of lipegfilgrastim to those of pegfilgrastim and filgrastim.

Methods

Embase was searched for trials examining the efficacy/safety of lipegfilgrastim, pegfilgrastim, or filgrastim. Outcomes included febrile neutropenia, severe neutropenia, duration of severe neutropenia, time to recovery of absolute neutrophil count, and incidence of bone pain. Direct comparisons were made using random-effects models. No trials directly compared lipegfilgrastim and filgrastim. Indirect comparisons were made between lipegfilgrastim and filgrastim with pegfilgrastim as the common comparator.

Results

This meta-analysis included a total of 5769 patients from 24 studies. Over all cycles, lipegfilgrastim showed a lower, nonsignificant risk of febrile neutropenia compared with pegfilgrastim. Lipegfilgrastim has a lower risk of febrile neutropenia versus filgrastim but was also not statistically significant. The risk ratio for severe neutropenia in cycle 1 was 0.80, a 20% reduction in favor of lipegfilgrastim. For cycles 2–4, the risk ratio was 0.53 (0.35, 0.79) for lipegfilgrastim versus pegfilgrastim. The risk of severe neutropenia in cycles 2–4 was also significantly lower for lipegfilgrastim (risk ratio 0.45, 0.27, 0.75, respectively). No significant differences were found for febrile neutropenia and severe neutropenia in cycle 1. However, in cycles 2–4, lipegfilgrastim was associated with significant and clinically meaningful reductions in risk of severe neutropenia versus either pegfilgrastim or filgrastim.

Conclusions

Compared with pegfilgrastim or filgrastim, lipegfilgrastim has a statistically significantly lower absolute neutrophil count recovery time; however, differences in duration of severe neutropenia and bone pain were nonsignificant.

Lipegfilgrastim for the prophylaxis and treatment of chemotherapy-induced neutropenia

Chemotherapy is frequently associated with hematologic toxicity. Neutropenia with or without fever is a relevant cause of morbidity, mortality and costs, compromising treatment administration and clinical outcomes. The development of granulocyte colony-stimulating factors has had a positive impact on the clinician's approach to neutropenia. Such agents, currently used for primary and secondary prophylaxis of chemotherapy-induced neutropenia and febrile neutropenia (FN), are effective in limiting hematologic toxicities and consequently allow the administration of intensive dose-dense regimens. Several biosimilar products of filgrastim have been developed over the years, showing effects similar to the originator drug. Until now, pegfilgrastim has been the only available long-acting factor, requiring just a single administration per chemotherapy cycle. The recent approval of the novel granulocyte colony-stimulating factors, lipegfilgrastim, offers interesting therapeutic alternatives. In fact, similar to pegfilgrastim, it has been demonstrated to reduce the duration of neutropenia and the occurrence of FN during chemotherapy safely.

Granulocyte colony-stimulating factor with or without stem cell factor extends time to premature ovarian insufficiency in female mice treated with alkylating chemotherapy

OBJECTIVE

To examine gonadal protective properties of granulocyte colony-stimulating factor (G-CSF) alone or in combination with stem cell factor (SCF) in female mice treated with high-dose alkylating chemotherapy.

DESIGN

Experimental laboratory animal study.

SETTING

Tertiary care academic hospital and research institute.

ANIMAL(S)

Six- and 8-week-old C57Bl/6 female mice.

INTERVENTION(S)

Adult female mice were treated with [1] cyclophosphamide and busulfan (CTx), [2] CTx + G-CSF/SCF, [3] CTx + G-CSF, or [4] normal saline and dimethyl sulfoxide (DMSO; vehicle control).

MAIN OUTCOME MEASURE(S)

Follicle counts, microvessel density, cellular response to DNA damage, and litter production.

RESULT(S)

G-CSF ± SCF increased microvessel density and decreased follicle loss in CTx-treated female mice compared with CTx-only treated female mice. Mice administered CTx alone exhibited premature ovarian insufficiency, with only 28% of mice producing two litters. However, 100% of mice receiving CTx with G-CSF + SCF, and 80% of mice receiving CTx + G-CSF alone produced at least three litters and 20% of mice in each group produced five litters.

CONCLUSION(S)

Treatment of mice with G-CSF decreases chemotherapy-induced ovarian follicle loss and extends time to premature ovarian insufficiency in female mice. Further studies are needed to validate these preclinical results in humans and compare efficacy with the established GnRH analogue treatments.

Effectiveness of daily versus non-daily granulocyte colony-stimulating factors in patients with solid tumours undergoing chemotherapy: a multivariate analysis of data from current practice

We conducted a multicentre, retrospective, observational study including patients with solid tumours (excluding breast cancer) that received granulocyte colony-stimulating factors (G-CSF) and chemotherapy. We investigated the effectiveness of daily vs. non-daily G-CSFs (pegfilgrastim) adjusting by potential confounders. The study included 391 patients (211 daily G-CSF; 180 pegfilgrastim), from whom 47.3% received primary prophylaxis (PP) (57.8% pegfilgrastim), 26.3% secondary prophylaxis (SP: initiation after cycle 1 and no reactive treatment in any cycle) (51.5% pegfilgrastim) and 26.3% reactive treatment (19.4% pegfilgrastim). Only 42.2% of patients with daily G-CSF and 46.2% with pegfilgrastim initiated prophylaxis within 72 h after chemotherapy, and only 10.5% of patients with daily G-CSF received it for ≥7 days. In the multivariate models, daily G-CSF was associated with higher risk of grade 3-4 neutropenia (G3-4N) vs. pegfilgrastim [odds ratio (OR): 1.73, 95% confidence interval (CI): 1.004–2.97]. Relative to SP, PP protected against G3-4N (OR for SP vs. PP: 6.0, 95%CI: 3.2–11.4) and febrile neutropenia (OR: 3.1, 95%CI: 1.1–8.8), and was associated to less chemotherapy dose delays and reductions (OR for relative dose intensity <85% for SP vs. PP: 3.1, 95%CI: 1.7–5.4) and higher response rate (OR: 2.1, 95%CI: 1.2–3.7). Data suggest that pegfilgrastim, compared with a daily G-CSF, and PP, compared with SP, could be more effective in preventing neutropenia and its related events in the clinical practice.

Primary prophylactic colony-stimulating factors for the prevention of chemotherapy-induced febrile neutropenia in breast cancer patients

BACKGROUND

High-dose or dose-intensive cytotoxic chemotherapy often causes myelosuppression and severe neutropenia among cancer patients. Severe neutropenia accompanied by fever, named febrile neutropenia (FN), is the most serious manifestation of neutropenia usually requiring hospitalization and intravenous antibiotics. FN and neutropenia can lead to chemotherapy treatment delays or dose reductions, which potentially compromises the effectiveness of cancer treatment and prospects for a cure. Granulocyte-macrophage (GM) and granulocyte colony-stimulating factors (G-CSFs) are administered during chemotherapy in order to prevent or reduce the incidence or the duration of FN and neutropenia.

OBJECTIVES

To assess the effect of prophylactic colony-stimulating factors (CSFs) in reducing the incidence and duration of FN, and all-cause and infection-related mortality during chemotherapy in patients with breast cancer.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, HEALTHSTAR, International Health Technology Assessment, SOMED, AMED and BIOSIS up to 8 August 2011. We also searched three Chinese databases (VIP, CNKI, CBM), the metaRegister of Controlled Trials, ClinicalTrials.gov, the World Health Organization's International Clinical Trials Registry Platform (WHO ICTRP) and OpenGrey.eu up to August 2011.

SELECTION CRITERIA

Randomized controlled trials (RCTs) comparing CSFs (any dose) with placebo or no treatment in patients with breast cancer at any stage, at risk of developing FN while undergoing any type of chemotherapy.

DATA COLLECTION AND ANALYSIS

We used pooled risk ratios (RR) with 95% confidence intervals (CIs) for binary outcomes. At least two review authors independently extracted data and assessed the risk of bias of the included studies. Trial authors were contacted for further details when information was unclear.

MAIN RESULTS

We included eight RCTs involving 2156 participants with different stages of breast cancer and chemotherapy regimens. The trials were carried out between 1995 and 2008 and judged as being at least at moderate risk of bias. The strength of the evidence was weak for the majority of outcomes, which was mostly because of the small numbers of evaluable patients, varying definitions, as well as unclear measurements of the trials' outcomes and uncertain influences of supportive treatments on them. In most trials, the chemotherapy regimens had a risk of FN that was below the threshold at which current guidelines recommend routine primary prophylaxis with CSFs. Using CSFs significantly reduced the proportion of patients with FN (RR 0.27; 95% CI 0.11 to 0.70; number needed to treat for an additional beneficial outcome (NNTB) 12) but there was substantial heterogeneity which can be explained by possible differential effects of G-CSFs and GM-CSFs and different definitions of FN. A significant reduction in early mortality was observed in CSF-treated patients compared to placebo or no treatment (RR 0.32; 95% CI 0.13 to 0.77; NNTB 79). This finding was based on 23 fatal events in 2143 patients; wherein 19 of these 23 events occurred in one study and 17 events were attributed to progression of the disease by the study authors. For infection-related mortality, there were no significant differences between CSF and control groups (RR 0.14; 95% CI 0.02 to 1.29). In CSF-treated patients, the risk for hospitalization was significantly reduced (RR 0.14; 95% CI 0.06 to 0.30; NNTB 13), as well as the use of intravenous antibiotics (RR 0.35; 95% CI 0.22 to 0.55; NNTB 18). The risks of severe neutropenia, infection or not maintaining the scheduled dose of chemotherapy did not differ between CSF-treated and control groups. CSFs frequently led to bone pain (RR 5.88; 95% CI 2.54 to 13.60; number needed to treat for an additional harmful outcome (NNTH) 3) and injection-site reactions (RR 3.59; 95% CI 2.33 to 5.53; NNTH 3).

AUTHORS' CONCLUSIONS

In patients with breast cancer receiving chemotherapy, CSFs have shown evidence of benefit in the prevention of FN. There is evidence, though less reliable, of a decrease of all-cause mortality during chemotherapy and a reduced need for hospital care. No reliable evidence was found for a reduction of infection-related mortality, a higher dose intensity of chemotherapy with CSFs or diminished rates of severe neutropenia and infections. The majority of adverse events reported from CSF use were bone pain and injection-site reactions but no conclusions could be drawn regarding late-term side effects.

Overview of supportive care in patients receiving chemotherapy: antiemetics, pain management, anemia, and neutropenia

With advancements in the field of oncology, more and more people are living with cancer. The prevalence of invasive cancer in the United States is estimated to be almost 12 million. The treatment of cancer as well as the malignancy itself can cause an immense number of side effects and other complications. This article explores the fundamentals of supportive care in patients receiving chemotherapy and radiation treatment including prevention of nausea and vomiting, pain management, treatment of anemia and neutropenia. Proper supportive care can help improve clinical outcomes, reduce medical costs, and help patients with cancer live longer, happier, and healthier lives. For these reasons, it is important for pharmacists to possess a solid understanding of how to prevent and treat the adverse effects of chemotherapy and radiation treatment.

Impact of primary prophylaxis with granulocyte colony-stimulating factor on febrile neutropenia and mortality in adult cancer patients receiving chemotherapy: a systematic review

PURPOSE

Randomized controlled trials (RCTs) of prophylactic granulocyte colony-stimulating factors (G-CSF) have demonstrated a significant reduction in febrile neutropenia (FN) after systemic chemotherapy. Several RCTs have been published recently that investigate the impact of G-CSF on mortality and relative dose-intensity (RDI).

METHODS

A comprehensive systematic review and meta-analysis of all reported RCTs comparing primary prophylactic G-CSF with placebo or untreated controls in adult solid tumor and malignant lymphoma patients was undertaken without language restrictions, using electronic databases, conference proceedings, and hand-searching techniques. Two reviewers extracted data independently. Summary estimates of relative risk (RR) with 95% CIs were estimated based on the method of Mantel-Haenszel and DerSimonian and Laird.

RESULTS

Seventeen RCTs were identified including 3,493 patients. For infection-related mortality, RR reduction with G-CSF compared with controls was 45% (RR = 0.55; 95% CI, 0.33 to 0.90; P = .018); for early mortality (all-cause mortality during chemotherapy period), it was 40% (RR = 0.60; 95% CI, 0.43 to 0.83; P = .002); and for FN, it was 46% (RR = 0.54; 95% CI, 0.43 to 0.67; P < .001). Average RDI was significantly higher in patients who received G-CSF compared with control patients (P < .001). Bone or musculoskeletal pain was reported in 10.4% of controls and 19.6% of G-CSF patients (RR = 4.03; 95% CI, 2.15 to 7.52; P < .001). Significant reductions in FN with G-CSF were observed in studies allowing secondary G-CSF prophylaxis in controls and in the three trials with concurrent prophylactic antibiotics in both treatment arms.

CONCLUSION

Prophylactic G-CSF reduces the risk of FN and early deaths, including infection-related mortality, while increasing RDI and musculoskeletal pain. There are insufficient data to assess the impact of G-CSF on disease-free and overall survival.

Cost-benefit analysis of granulocyte colony-stimulating factor in the management of elderly cancer patients

Health care costs continue to rise, and hospitalization represents the single largest component of direct medical costs associated with cancer care. Neutropenia and its complications including febrile neutropenia (FN) remain the major dose-limiting toxicity of systemic cancer chemotherapy. The risk of FN varies considerably across treatment regimens but appears to be significantly higher among elderly patients. The colony-stimulating factors (CSFs) have been used effectively in a variety of clinical settings to prevent or treat FN and to assist patients receiving dose-intensive chemotherapy with or without stem cell support. Several randomized controlled trials (RCTs) have demonstrated the clinical efficacy of the prophylactic use of CSFs. A recently presented meta-analysis of the available RCTs has confirmed the efficacy of prophylactic CSFs. The cost of these agents, along with their large-scale clinical use, has prompted a number of economic investigations. Economic models based on measures of resource utilization derived from RCTs have provided FN risk threshold estimates for the cost-saving use of prophylactic CSF. A number of important studies concerning the clinical and economic impact of these agents in elderly cancer patients have been reported during the past year. Continuing clinical and economic evaluation along with an updating of clinical practice guidelines especially related to elderly patients is recommended because of rapid technologic and clinical advances.

Mitomycin C: a clinical update

Mitomycin C was reviewed in this journal 25 years ago and an update of its clinical usefulness is appropriate. The current review is based on representative publications covering clinical trials performed throughout the world. Single agent activity in each of the major neoplastic diseases has been reassessed when possible and the most important combinations evaluated. It is concluded that mitomycin C has a definite place in the treatment of localized bladder cancer, is active, but needs to be redefined, in the context of newer regimens for breast, head and neck, and non-small cell lung cancers, is active in, but is being displaced by, other drugs in cervical, gastric and pancreatic cancers, and is probably no longer of therapeutic value in colon cancer. It is also recognized that as many newer treatments have clinical success, the therapeutic role of mitomycin C will require continuing re-investigation.

Tailored chemotherapy to equal toxicity: is it possible?

Conventional dosage of chemotherapy based on body surface area in patients with normal organ functions will result in marked interindividual variations in systemic exposure to the cytostatics used. This will result in over- and undertreatment of the individual patient associated with unwarranted toxicity and suboptimal outcome. The intention to modify dosage is motivated by a possible correlation between toxicity and outcome. New dosage strategies with individual tailoring of the therapy should be investigated with the aim of increasing the efficacy of therapy without increasing its toxicity. Pharmacokinetic monitoring using the limited sampling procedure could be one alternative, another toxicity-guided dosage. The dosage scheme used for tailored FEC polychemotherapy (six dose levels), based on therapy to equivalent haematological toxicity, has been clinically applicable in the multicentre setting for both adjuvant and preoperative therapy. In the adjuvant setting it has resulted in the delivery of significantly higher epirubicin and cyclophosphamide doses without increasing acute toxicity to the same extent; in two out of three patients no difference in acute toxicity could be verified for the highest two dose levels compared with the lower dose levels. In short, we could obtain better results with our present arsenal of cytostatics if we used them better.