Results of a phase III prospective, randomised trial, comparing mitoxantrone and vinorelbine (MV) in combination with standard FAC/FEC in front-line therapy of metastatic breast cancer

Progression-Free Survival and Time to Progression as Real Surrogate End Points for Overall Survival in Advanced Breast Cancer: A Meta-Analysis of 37 Trials

BACKGROUND

Progression-free survival (PFS) and time to progression (TTP) have been reported to correlate with overall survival (OS) in several cancer types. To our knowledge, however, the correlation between them is unclear.

METHODS

A literature-based meta-analysis was performed to assess whether PFS and TTP can be considered reliable surrogate end points for OS in a phase 3 clinical trial of advanced breast cancer (ABC). The median hazard ratios of PFS/TTP and OS were analyzed by determining their nonparametric Spearman rank correlation coefficients (Rs).

RESULTS

A total of 37 trials with 38 treatment arms and 14,966 patients were selected for analysis. The Rs between the median PFS/TTP and OS was 0.405 (95% confidence interval [CI], 0.191-0.582; P = .003), and the correlation coefficient between the hazard ratios of PFS/TTP and OS was 0.555 (95% CI, 0.277-0.748; P = .003). PFS/TTP was closely correlated with OS in the trials of targeted therapy-based treatment (Rs = 0.872; 95% CI, 0.619-0.962; P = .0001) and of PFS/TTP or OS benefit (Rs = 0.753 and Rs = 0.821, respectively) for ABC.

CONCLUSIONS

Both PFS and TTP can be considered valid surrogate end points for OS in the trials of targeted therapy-based treatments and clinical benefits for ABC. Further research is necessary to clarify the surrogacy of PFS/TTP for OS in other trials of targeted therapy-based treatments for ABC.

A systematic review of vinorelbine for the treatment of breast cancer

The purpose of this study was to investigate the efficacy and safety profile of vinorelbine-based chemotherapy in different settings for the treatment of breast cancer. We performed a computerized search using combinations of the following keywords: "breast cancer", "breast neoplasms", "trial", "vinorelbine" and "navelbine". A total of 20 trials were included in this analysis, with a total of 5,080 patients accrued. Taxane was associated with enhanced overall survival (OS; p = 0.027) and response rate (RR; p = 0.037) as compared with vinorelbine in monotherapy, but did not show significantly favored progression-free survival (PFS; p = 0.136). Vinorelbine alone was equivalent to fluoropyrimidine treatment in RR (p = 0.79) for the treatment of metastatic breast cancer. For vinorelbine-combined regimens, the analysis showed that the vinorelbine group gave similar results as other regimens for OS (p = 0.849) and PFS (p = 0.143). The RR of vinorelbine-combined regimens was slightly better than that of the other regimens (OR, 1.17), but the difference was not statistically significant. In neoadjuvant setting, vinorelbine treatment was as active as AC (doxorubicin, cyclophosphamide) or DAC (doxorubicin, cyclophosphamide, docetaxel) regimens with respect to RR (p = 0.76) and pathologic complete response (pCR; p = 0.77), but showed lower occurrence of grade 3/4 adverse effects. The analysis also demonstrated that vinorelbine-containing therapy is effective as adjuvant, front-line or salvage therapy of metastatic breast cancer, even for patients who were previously treated with anthracyclines or taxanes.

A multicenter prospective phase II randomized trial of epirubicin/vinorelbine versus pegylated liposomal doxorubicin/vinorelbine as first-line treatment in advanced breast cancer. A GOIM study

BACKGROUND

To evaluate activity and tolerability of two anthracycline-containing regimens as first-line treatment for anthracycline-naïve relapsed breast cancer patients.

METHODS

Patients with relapsed breast cancer not previously treated with adjuvant anthracyclines were randomly assigned to epirubicin/vinorelbine (arm A: EPI/VNB, EPI 90 mg/m2 on day 1, VNB 25 mg/m2 on days 1,5 plus G-CSF subcutaneously on days 7-12, with cycles repeated every 21 days), or to pegylated liposomal doxorubicin/VNB (arm B: PLD/VNB, PLD 40 mg/m2 on day 1, VNB 30 mg/m2 on days 1, 15, with cycles repeated every 4 weeks). Primary objective was to evaluate the efficacy of the two regimens in terms of response rate, secondarily toxicity, progression free survival and overall survival.

RESULTS

One hundred and four patients have been enrolled (arm A 54, arm B 50): characteristics were well balanced between the 2 arms. Responses were as follows: arm A, 3 (5.6%) CR, 20 (37%) PR, (ORR 42.6%, 95%CI 29.3%-55.9%); arm B, 8 (16%) CR, 18 (36%) PR, (ORR 52%, 95%CI 38.2%-65.8%). Median progression free survival was 10.7 months in arm A (95% CI, 8.7-12.6), and 8.8 months in arm B (95% CI, 7.1-10.5). Median overall survival was 34.6 months in arm A (95%CI, 19.5-49.8) and 24.8 months in arm B (95%CI, 15.7-33.9). As toxicity concerns, both treatment regimens were well tolerated; myelosuppression was the dose-limiting toxicity, with G3-4 neutropenia occurring in 18.5% and 22% of the patients of arm A and B, respectively. No relevant differences in main toxic effects have been observed between the two arms, except for alopecia, more common in arm A, and cutaneous toxicity, observed only in arm B. No clinical congestive heart failures have been observed, one case of tachyarrhythmia was reported after the last EPI/VNB cycle, and two reversible ≥ 20% LVEF decreases have been observed in arm A.

CONCLUSIONS

Both anthracycline- containing regimens evaluated in the present study seem to be active and with a satisfactory tolerability in anthracycline-naïve relapsed breast cancer patients.

How Long Have I Got? Estimating Typical, Best-Case, and Worst-Case Scenarios for Patients Starting First-Line Chemotherapy for Metastatic Breast Cancer: A Systematic Review of Recent Randomized Trials

Purpose

To estimate scenarios for survival for women with metastatic breast cancer (MBC) who are starting chemotherapy.

Patients and Methods

We sought randomized, first-line chemotherapy trials for MBC published from 1999 to 2009. We recorded median progression-free survival (PFS) and median overall survival (OS) and extracted the following percentiles (represented scenario) from each OS curve: 90th (worst-case), 75th (lower-typical), 25th (upper-typical), and 10th (best-case). We also estimated these scenarios for each OS curve by multiplying its median by four simple multiples: 0.25 (worst-case), 0.5 (lower-typical), 2 (upper-typical), and 3 (best-case). Estimates were deemed accurate if they were within 0.75 to 1.33 times the actual value.

Results

From 36 trials (13,083 women), the mean for median PFS was 7.6 months (interquartile range [IQR], 6.0 to 9.0 months), the mean for median OS was 21.7 months (IQR,18.2 to 24.0 months), and the mean for the ratio of median OS to median PFS was 3.0 (IQR, 2.4 to 3.5). The mean for each OS scenario was worst-case, 6.3 months (IQR, 4.8 to 7.5 months); lower-typical, 11.9 months (IQR, 9.9 to 13.2 months); upper-typical, 36.2 months (IQR, 31.1 to 41.3 months); and best-case, 55.8 months (IQR, 47.5 to 60.2 months). Simple multiples of the median gave accurate estimates of the worst-case scenario in 73% of OS curves, lower-typical in 97%, upper-typical in 95%, and best-case in 96%. OS was longer in trials with higher proportions of estrogen receptor–positive tumors (P = .001) and in trials of trastuzumab-treated human epidermal growth factor receptor 2–positive tumors (P = .001).

Conclusion

Simple multiples of an OS curve's median can accurately estimate typical (half to double the median), best-case (triple the median), and worst-case (one quarter of the median) scenarios for survival.

Different anthracycline derivates for reducing cardiotoxicity in cancer patients

BACKGROUND

The use of anthracyclines is limited by the occurrence of cardiotoxicity. In an effort to prevent this cardiotoxicity, different anthracycline derivates have been studied.

OBJECTIVES

To determine the occurrence of cardiotoxicity with the use of different anthracycline derivates in cancer patients.

SEARCH STRATEGY

We searched The Cochrane Central Register of Controlled Trials (CENTRAL), (The Cochrane Library, Issue 2, 2009), MEDLINE (1966 to 29 May 2009) and EMBASE (1980 to 2 June 2009). In addition, we searched reference lists of relevant articles, conference proceedings and ongoing-trials-databases.

SELECTION CRITERIA

Randomised controlled trials (RCTs) in which different anthracycline derivates were compared in cancer patients (children and adults).

DATA COLLECTION AND ANALYSIS

Two authors independently performed study selection, assessment of risk of bias and data-extraction including adverse effects.

MAIN RESULTS

We identified five RCTs of varying quality addressing epirubicin versus doxorubicin (1036 patients) with the same dose. The meta-analysis showed no evidence for a significant difference in the occurrence of clinical heart failure between the treatment groups (RR = 0.36, 95% CI 0.12 to 1.11). However, there is some suggestion of a lower rate of clinical heart failure in patients treated with epirubicin.We identified two RCTs with varying quality addressing liposomal-encapsulated doxorubicin versus conventional doxorubicin (521 patients). The meta-analysis showed a significantly lower rate of both clinical heart failure and clinical and subclinical heart failure combined in patients treated with liposomal-encapsulated doxorubicin (RR = 0.20, 95% CI 0.05 to 0.75 and RR = 0.38, 95% CI 0.24 to 0.59 respectively). It should be noted that in one of the studies patients in the liposomal-encapsulated doxorubicin group received a higher cumulative anthracycline dose than patients in the doxorubicin group.For the other possible combinations of different anthracycline derivates only one RCT (epirubicin versus liposomal-encapsulated doxorubicin) or no RCT was identified.

AUTHORS' CONCLUSIONS

We are not able to favour either epirubicin or doxorubicin when given with the same dose. Based on the currently available evidence on heart failure, we conclude that in adults with a solid tumour liposomal-encapsulated doxorubicin should be favoured over doxorubicin. For both epirubicin versus doxorubicin and liposomal-encapsulated doxorubicin versus conventional doxorubicin no conclusions can be made about the effects of treatment in children treated with anthracyclines and also not in patients diagnosed with leukaemia. More research is needed. For other combinations of anthracycline derivates not enough evidence was available to make definitive conclusions about the occurrence of cardiotoxicity in patients treated with anthracyclines.

Different anthracycline derivates for reducing cardiotoxicity in cancer patients

BACKGROUND

The use of anthracyclines is limited by the occurrence of cardiotoxicity. In an effort to prevent this cardiotoxicity, different anthracycline derivates have been studied.

OBJECTIVES

To determine the occurrence of cardiotoxicity with the use of different anthracycline derivates in cancer patients.

SEARCH STRATEGY

We searched The Cochrane Central Register of Controlled Trials (CENTRAL), (The Cochrane Library, Issue 2, 2009), MEDLINE (1966 to 29 May 2009) and EMBASE (1980 to 2 June 2009). In addition, we searched reference lists of relevant articles, conference proceedings and ongoing-trials-databases.

SELECTION CRITERIA

Randomised controlled trials (RCTs) in which different anthracycline derivates were compared in cancer patients (children and adults).

DATA COLLECTION AND ANALYSIS

Two authors independently performed study selection, assessment of risk of bias and data-extraction including adverse effects.

MAIN RESULTS

We identified five RCTs of varying quality addressing epirubicin versus doxorubicin (1036 patients) with the same dose. The meta-analysis showed no evidence for a significant difference in the occurrence of clinical heart failure between the treatment groups (RR = 0.36, 95% CI 0.12 to 1.11). However, there is some suggestion of a lower rate of clinical heart failure in patients treated with epirubicin.We identified two RCTs with varying quality addressing liposomal-encapsulated doxorubicin versus conventional doxorubicin (521 patients). The meta-analysis showed a significantly lower rate of both clinical heart failure and clinical and subclinical heart failure combined in patients treated with liposomal-encapsulated doxorubicin (RR = 0.20, 95% CI 0.05 to 0.75 and RR = 0.38, 95% CI 0.24 to 0.59 respectively). It should be noted that in one of the studies patients in the liposomal-encapsulated doxorubicin group received a higher cumulative anthracycline dose than patients in the doxorubicin group.For the other possible combinations of different anthracycline derivates only one RCT (epirubicin versus liposomal-encapsulated doxorubicin) or no RCT was identified.

AUTHORS' CONCLUSIONS

We are not able to favour either epirubicin or doxorubicin when given with the same dose. Based on the currently available evidence on heart failure, we conclude that in adults with a solid tumour liposomal-encapsulated doxorubicin should be favoured over doxorubicin. For both epirubicin versus doxorubicin and liposomal-encapsulated doxorubicin versus conventional doxorubicin no conclusions can be made about the effects of treatment in children treated with anthracyclines and also not in patients diagnosed with leukaemia. More research is needed. For other combinations of anthracycline derivates not enough evidence was available to make definitive conclusions about the occurrence of cardiotoxicity in patients treated with anthracyclines.

Progression-free survival as a surrogate endpoint in advanced breast cancer

OBJECTIVES

Progression-free survival (PFS) has not been validated as a surrogate endpoint for overall survival (OS) for anthracycline (A) and taxane-based (T) chemotherapy in advanced breast cancer (ABC). Using trial-level, meta-analytic approaches, we evaluated PFS as a surrogate endpoint.

METHODS

A literature review identified randomized, controlled A and T trials for ABC. Progression-based endpoints were classified by prospective definitions. Treatment effects were derived as hazard ratios for PFS (HRPFS) and OS (HROS). Kappa statistic assessed overall agreement. A fixed-effects regression model was used to predict HROS from observed HRPFS. Cross-validation was performed. Sensitivity and subgroup analyses were performed for PFS definition, year of last patient recruitment, line of treatment, and constant rate assumption.

RESULTS

Sixteen A and fifteen T trials met inclusion criteria, producing seventeen A (n = 4,323) and seventeen T (n = 5,893) trial-arm pairs. Agreement (kappa statistic) between the direction of HROS and HRPFS was 0.71 for A (p = .0029) and 0.75 for T (p = .0028). While HRPFS was a statistically significant predictor of HROS for both A (p = .0019) and T (p = .012), the explained variances were 0.49 (A) and 0.35 (T). In cross-validation, 97 percent of the 95 percent prediction intervals crossed the equivalence line, and the direction of predicted HROS agreed with observed HROS in 82 percent (A) and 76 percent (T). Results were robust in sensitivity and subgroup analyses.

CONCLUSIONS

This meta-analysis suggests that the trial-level treatment effect on PFS is significantly associated with the trial-level treatment effect on OS. However, prediction of OS based on PFS is surrounded with uncertainty.

Mitoxantrone plus vinorelbine in pretreated patients with metastatic breast cancer

Vinorelbine and mitoxantrone have both been demonstrated to have significant antitumor activity in patients with breast cancer. The aim of this study was to evaluate the efficacy and safety of the combination as second or third line treatment in patients with metastatic breast cancer (MBC). Fifty-one previously treated patients with MBC were enrolled from October 2001 to May 2004 and 48 were eligible for evaluation. Median age was 59 years (range 33-82) and ECOG performance status was < or =2. Distant sites of metastasis were as follows: liver 64%, bone 49%, lung 36%, lymph nodes 6%, skin 4%, brain 2% and other sites 6%. All patients received vinorelbine 20 mg/m(2), D1+8 and mitoxantrone 10 mg/m(2) D8 every 21 days for 6 cycles. All eligible patients were analyzed for toxicity and response. Two patients (4%) achieved complete response and 12 (25.5%) partial response. The objective overall response rate was 29.5% (95% confidence interval [CI] 17 - 45), 9 (19%) patients had stable disease, 17 (36%) had progressive disease and 7 (15%) were non-evaluable. After a median follow up of 18 months, overall survival was 13 months (range 0.8 - 38+) and median time to disease progression was 5 months (range 1 - 32). A total of 280 cycles was delivered. The relative dose intensities of mitoxantrone and vinorelbine were 79% and 77%, respectively. Toxicities (grade III-IV) were as follows: leukopenia 18 (38%), neutropenia 21 (45%), thrombocytopenia 1 (2%), anemia 4 (8.5%), alopecia 2 (4%) and constipation 1 (2%). Febrile neutropenia was recorded in one patient. There were no treatment related deaths. The combination of mitoxantrone and vinorelbine is an effective regimen with manageable toxicity in pretreated patients with advanced breast cancer.

Different anthracycline derivates for reducing cardiotoxicity in cancer patients

BACKGROUND

The use of anthracycline chemotherapy is limited by the occurrence of cardiotoxicity. In an effort to prevent this cardiotoxicity, different anthracycline derivates have been studied.

OBJECTIVES

The primary objective was to determine the occurrence of cardiotoxicity with the use of different anthracycline derivates in cancer patients.

SEARCH STRATEGY

We searched the databases of the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 1, 2005), MEDLINE (1966 to April 2005) and EMBASE (1980 to April 2005). In addition, we searched reference lists of relevant articles, conference proceedings and ongoing trials databases.

SELECTION CRITERIA

Randomised controlled trials (RCTs) in which different anthracycline derivates were compared in cancer patients (children and adults).

DATA COLLECTION AND ANALYSIS

Two authors independently performed the study selection, quality assessment and data-extraction including adverse effects.

MAIN RESULTS

We identified five RCTs of varying quality addressing epirubicin versus doxorubicin (1036 patients) with the same dose. The meta-analysis showed no evidence for a significant difference in the occurrence of clinical heart failure between the treatment groups (RR = 0.36, 95% CI 0.12 to 1.11). However, there is some suggestion of a lower rate of clinical heart failure in patients treated with epirubicin. We identified two RCTs with varying quality addressing liposomal-encapsulated doxorubicin versus conventional doxorubicin (521 patients). The meta-analysis showed a significantly lower rate of both clinical heart failure and clinical and subclinical heart failure combined in patients treated with liposomal-encapsulated doxorubicin (RR = 0.20, 95% CI 0.05 to 0.75 and RR = 0.38, 95% CI 0.24 to 0.59 respectively). It should be noted that in one of the studies patients in the liposomal-encapsulated doxorubicin group received a higher cumulative anthracycline dose than patients in the doxorubicin group. For the other possible combinations of different anthracycline derivates only one RCT was identified.

AUTHORS' CONCLUSIONS

We are not able to favour either epirubicin or doxorubicin when given with the same dose. Based on the currently available evidence on heart failure, we conclude that in adults with a solid tumour liposomal-encapsulated doxorubicin should be favoured over doxorubicin. For both epirubicin versus doxorubicin and liposomal-encapsulated doxorubicin versus conventional doxorubicin no conclusions can be made about the effects of treatment in children treated with anthracyclines and also not in patients diagnosed with leukaemia. More research is needed. For other combinations of anthracycline derivates not enough evidence was available to make definitive conclusions about the occurrence of cardiotoxicity in patients treated with anthracyclines.

Vinorelbine in the management of breast cancer: New perspectives, revived role in the era of targeted therapy

Vinorelbine is a semi-synthetic vinca alkaloid that has been shown active in many tumour types and is currently registered for the treatment of advanced breast cancer (ABC) and non-small cell lung cancer (NSCLC). This agent has a generally favourable safety profile, and may be suitable for use in special populations such as the elderly and/or frail patient. However, with the taxanes firmly established as standard second line treatment for ABC after failure of an anthracycline, vinorelbine has been generally relegated for use as third line therapy, in competition with the oral compound capecitabine. More recently, the exciting results observed with the combination of vinorelbine and trastuzumab in patients with Her-2 overexpressing/amplified tumours, as well as the development of a reliable formulation and revised schedule of oral vinorelbine with proven activity in ABC appear to have revived the interest in this compound in the management of this disease. There are still a number of unanswered questions that will have to be addressed by properly designed, adequately powered randomised clinical trials.

The role of the liposomal anthracyclines and other systemic therapies in the management of advanced breast cancer

For patients whose breast cancers are not responsive to endocrine therapy, there are a large number of cytotoxic drugs that will induce a response. In spite of the introduction of new, very active drugs such as the taxanes, vinorelbine, capecitabine, gemcitabine, and trastuzumab, the anthracyclines are still as active as any--and more active than most--drugs used to treat breast cancer. Their inclusion in combinations to treat early and advanced disease prolongs survival. However, they cause nausea, vomiting, alopecia, myelosuppression, mucositis, and cardiomyopathies. There is no evidence that increasing the dose of conventional anthracyclines or any other of the cytotoxics beyond standard doses will improve outcomes. Schedule may be more important than dose in determining the benefit of cytotoxics used to treat breast cancer. Weekly schedules and continuous infusions of 5-fluorouracil and doxorubicin may have some advantages over more intermittent schedules. Liposomal formations of doxorubicin reduce toxicity, including cardiotoxicity; theoretically they should also be more effective because of better targeting of tumor over normal tissues. Both pegylated liposomal doxorubicin (Doxil/Caelyx [PLD]) and liposomal doxorubicin (Myocet [NPLD]) appeared to be as effective as conventional doxorubicin and much less toxic in multiple phase II and phase III studies. PLD has been evaluated in combinations with cyclophosphamide, the taxanes, vinorelbine, gemcitabine, and trastuzumab, and NPLD has been evaluated in combination with cyclophosphamide and trastuzumab. Both liposomal anthracyclines are less cardiotoxic than conventional doxorubicin. The optimal dose of PLD is lower than that of conventional doxorubicin or NPLD. Patients treated with PLD have almost no alopecia, nausea, or vomiting, but its use is associated with stomatitis and hand-foot syndrome, which can be avoided or minimized with the use of proper dose-schedules. In contrast, the optimal dose-schedule of NPLD is nearly identical to that of conventional doxorubicin. The toxicity profile of NPLD is similar to that of conventional doxorubicin, but toxicities are less severe and NPLD is better tolerated than conventional doxorubicin at higher doses.

Phase III study of intravenous vinorelbine in combination with epirubicin versus epirubicin alone in patients with advanced breast cancer: a Scandinavian Breast Group Trial (SBG9403)

PURPOSE

To determine whether the addition of intravenous (IV) vinorelbine to epirubicin increased the progression-free survival in first-line treatment of metastatic breast cancer.

PATIENTS AND METHODS

A total of 387 patients were randomly assigned to receive IV epirubicin 90 mg/m(2) on day 1 and vinorelbine 25 mg/m(2) on days 1 and 8, or epirubicin 90 mg/m(2) IV on day 1. Both regimens were given every 3 weeks for a maximum of 1 year but discontinued prematurely in the event of progressive disease or severe toxicity. In addition, epirubicin was discontinued at a cumulative dose of 1000 mg/m(2) (950 mg/m(2) from June 1999). Prior anthracycline-based adjuvant chemotherapy and prior chemotherapy for metastatic breast cancer was not allowed. Reported results were all based on intent-to-treat analyses.

RESULTS

Overall response rates to vinorelbine and epirubicin, and epirubicin alone, were 50% and 42%, respectively (P =.15). The complete response rate was significantly superior in the combination arm (17% v 10%; P =.048) as was median duration of progression-free survival (10.1 months v 8.2 months; P =.019). Median survival was similar in the two arms (19.1 months v 18.0 months; P =.50). Leukopenia related complications, stomatitis, and peripheral neuropathy were more common in the combination arm. The incidences of cardiotoxicity and constipation were similar in both arms.

CONCLUSION

Addition of vinorelbine to epirubicin conferred a significant advantage in terms of complete response rate and progression-free survival, but not in terms of survival.

Vinorelbine-related cardiac events: a meta-analysis of randomized clinical trials

Several cases of cardiac adverse reactions related to vinorelbine (VNR) have been reported in the literature. In order to quantify the incidence of these cardiac events, we performed a meta-analysis of clinical trials comparing VNR with other chemotherapeutic agents in the treatment of various malignancies. Randomized clinical trials comparing VNR with other drugs in the treatment of cancer were searched in Medline, Embase, Evidence-based Medicine Reviews databases and the Cochrane library from 1987 to 2002. Outcomes of interest were severe cardiac events, toxic deaths and cardiac event-related deaths reported in each publication. We found 19 trials, involving 2441 patients treated by VNR and 2050 control patients. The incidence of cardiac events with VNR was 1.19% [95% confidence interval (CI) (0.75; 1.67)]. There was no difference in the risk of cardiac events between VNR and other drugs [odds ratio: 0.92, 95% CI (0.54; 1.55)]. The risk of VNR cardiac events was similar to vindesine (VDS) and other cardiotoxic drugs [fluorouracil, anthracyclines, gemcitabine (GEM) em leader ]. Even if it did not reach statistical significance because of a few number of cases, the risk was lower in trials excluding patients with cardiac history, and seemed to be higher in trials including patients with pre-existing cardiac diseases. Vinorelbine-related cardiac events concern about 1% of treated patients in clinical trials. However, the risk associated with VNR seems to be similar to that of other chemotherapeutic agents in the same indications.

Vinorelbine, methotrexate and fluorouracil (VMF) as first-line therapy in metastatic breast cancer: a randomized phase II trial

BACKGROUND

The purpose of this study was to determine the best tolerated and efficacious dose of vinorelbine given once or twice in 3-week cycles in combination with methotrexate and fluorouracil (VMF).

PATIENTS AND METHODS

Vinorelbine 40 mg/m(2) was given as follows: 20 mg/m(2) on days 1 and 8 (group 1); 30 mg/m(2) on day 1 and 10 mg/m(2) on day 8 (group 2); or 40 mg/m(2) on day 1 (not exeeding 60 mg/m(2)) (group 3). The methotrexate dose was 40 mg/m(2) on day 1 and the fluorouracil dose 600 mg/m(2) on days 1 and 8. Thirty patients with evaluable metastases were randomly allocated to the groups (first step). The second step was to exclude the worst tolerated regimen and then to expand the study to 60 patients. Thus, group 1 had 26 patients, group 2 had 24 patients and group 3 had 10 patients.

RESULTS

World Health Organization (WHO) grade 3 hematological toxicity occurred in 23%, 36% and 50% of patients and grade 4 in 39%, 32% and 50% of patients in groups 1, 2 and 3, respectively; grade 3 infections were observed in 15%, 9% and 10% of patients in groups 1, 2 and 3, and grade 4 infections in 5% and 10% of patients in groups 2 and 3, respectively. Nonhematological toxicity included a mild to moderate neurotoxicity manifesting as constipation, abdominal colics and myalgia in the majority of patients. One patient in group 3 had serious convulsions after vinorelbine administration; she also developed neutropenic sepsis; all symptoms were reversible. No patient died from side-effects. The objective response rates were 50%, 55% and 44% for groups 1, 2 and 3, respectively. Median time to progression was 7, 10 and 8 months and median survival time was 26, 23 and 16 months in groups 1, 2 and 3, respectively.

CONCLUSION

VMF regimens where the vinorelbine dose (40 mg/m(2)) is divided (20 + 20 mg/m(2) and 30 + 10 mg/m(2)) between days 1 and 8 of a 3-week cycle are equally well tolerated and the efficacy is comparable to other modern first line regimens used in the treatment of metastatic breast cancer.

Combination chemotherapy for metastatic breast cancer

Despite more than four decades of effort, the improvement in survival in metastatic breast cancer has been modest. Recently, however, new drugs such as the taxanes have emerged as pivotal agents in the treatment of metastatic disease and they are now being investigated in the adjuvant setting. In addition, the introduction of molecularly targeted therapies such as trastuzumab provides a new paradigm for the development of biologic treatments. The incorporation of trastuzumab into new combination regimens based on potential molecular synergies is a focus of current research.

A review of vinorelbine in the treatment of breast cancer

As combinations and sequences of anthracyclines and taxanes increasingly become standard adjuvant treatment for early breast cancer, a major need for new treatment options for metastatic breast cancer will arise. Vinorelbine is highly active in the treatment of metastatic breast cancer, both as a single agent and in combination regimens. Furthermore, it is well tolerated, with a low incidence of subjective toxicities. It is anticipated, therefore, that vinorelbine will become increasingly utilized for treating metastatic breast cancer due to its favorable safety profile, good tolerability, and promising results in combination with other chemotherapy agents. Combinations with trastuzumab and newer molecular targeting agents are being explored. Doublets or triplets of vinorelbine with drugs other than anthracyclines and taxanes could be considered in the next generation of adjuvant and neoadjuvant trials, where it is anticipated that anthracycline/taxane combinations are likely to replace anthracycline/cyclophosphamide combinations as the mainstay of adjuvant treatment.