A randomized trial of cyclophosphamide, doxorubicin, and prednisone versus cyclophosphamide, 5-fluorouracil, and prednisone in patients with metastatic breast cancer

Multiple-treatments meta-analysis of chemotherapy and targeted therapies in advanced breast cancer

BACKGROUND

Many systemic nonhormonal regimens have been evaluated across several hundreds of randomized trials in advanced breast cancer. We aimed to quantify the relative merits of these regimens in prolonging survival.

METHODS

We performed a systematic review of all trials that compared different regimens involving chemotherapy and/or targeted therapy in advanced breast cancer (1973-2007). Regimens were categorized a priori into different treatment types. We performed multiple-treatments meta-analysis and calculated hazard ratios for each treatment category relative to monotherapy with old agents (ie, regimens not including anthracyclines, anthracenediones, vinorelbine, gemcitabine, capecitabine, taxanes, marimastat, thalidomide, trastuzumab, lapatinib, or bevacizumab).

RESULTS

We identified 370 eligible randomized trials (54,189 patients), of which 172 (31,552 patients) compared different types of treatment. Survival data from 148 comparisons pertaining to 128 of the 172 trials (26,031 patients, 22 different types of treatment) were available for inclusion in the multiple-treatments meta-analysis. Compared with single-agent chemotherapy with old nonanthracycline drugs, anthracycline regimens achieved 22%-33% relative risk reductions in mortality (ie, hazard ratio [HR] for standard-dose anthracycline-based combination: 0.67, 95% credibility interval [CrI] 0.57-0.78). Several newer regimens achieved further benefits (eg, HR [95% CrI] 0.67 [0.55-0.81] for single-drug taxane, 0.64 [0.53-0.78] for combination of anthracyclines with taxane, 0.49 [0.37-0.67] for taxane-based combination with capecitabine or gemcitabine), and similar benefits were seen with several regimens including molecular targeted treatments. Most regimens had very similar efficacy profiles (<5% difference in HR) as first- and subsequent-line therapies.

CONCLUSIONS

Stepwise improvements in efficacy of chemotherapy and targeted treatments cumulatively have achieved major improvements in the survival of patients with advanced breast cancer. Many options that can be used in first and subsequent lines of therapy have comparable efficacy profiles.

Antitumour antibiotic containing regimens for metastatic breast cancer

BACKGROUND

Antitumour antibiotics are used in the management of metastatic breast cancer. Some of these agents have demonstrated higher tumour response rates than non-antitumour antibiotic regimens, however a survival benefit has not been established in this setting.

OBJECTIVES

To identify and review the randomised evidence comparing anti-tumour antibiotic containing chemotherapy regimens with regimens not containing an anti-tumour antibiotic in the management of women with metastatic breast cancer.

SEARCH STRATEGY

The specialised register maintained by the Editorial Base of the Cochrane Breast Cancer Group was searched on 2nd May, 2003 using the codes for "advanced breast cancer" and "chemotherapy". Details of the search strategy and coding applied by the Group to create the register are described in the Group's module on The Cochrane Library.

SELECTION CRITERIA

Randomised trials comparing anti-tumour antibiotic containing regimens with regimens not containing anti-tumour antibiotics in women with metastatic breast cancer.

DATA COLLECTION AND ANALYSIS

Data were collected from published trials. Studies were assessed for eligibility and quality, and data were extracted by two independent reviewers. Hazard ratios (HRs) were derived from time-to-event outcomes where possible, and a fixed effect model was used for meta-analysis. Response rates were analysed as dichotomous variables. Quality of life and toxicity data were extracted where present. A primary analysis was conducted for all trials and by class of antitumour antibiotic.

MAIN RESULTS

Thirty-three trials reporting on 45 treatment comparisons were identified. All trials published results for tumour response and 26 trials published time-to-event data for overall survival. The observed 4084 deaths in 5284 randomised women did not demonstrate a statistically significant difference in survival between regimens that contained antitumour antibiotics and those that did not (HR 0.97, 95% CI 0.91 to 1.03, P = 0.35) and no significant heterogeneity. Antitumour antibiotic regimens were favourably associated with time-to-progression (HR 0.84, 95% CI 0.77 to 0.91) and tumour response rates (odds ratio (OR) 1.34, 95% CI 1.21 to 1.48) although statistically significant heterogeneity was observed for these outcomes. These associations were consistent when the analysis was restricted to the 29 trials that reported on anthracyclines. Patients receiving anthracycline-containing regimens were also more likely to experience toxic events compared to patients receiving non-antitumour antibiotic regimens. No statistically significant difference was observed in any outcome between mitoxantrone-containing and non-antitumour antibiotic-containing regimens.

REVIEWERS' CONCLUSIONS

Compared to regimens without antitumour antibiotics, regimens that contained these agents showed a statistically significant advantage for tumour response and time to progression in women with metastatic breast cancer but were not associated with an improvement in overall survival. The favourable effect on tumour response and time to progression observed in anthracycline-containing regimens was also associated with greater toxicity.

Does a drug do better when it is new?

BACKGROUND

When assessing a new, promising therapeutic approach, a clinician's perception of a drug's effectiveness may be shaped by different kinds of phenomena, and among them, a favorable attitude towards new treatments, and as a result a tendency to overestimate their efficacy (wish bias).

MATERIALS AND METHODS

A retrospective study of published randomized clinical trials of doxorubicin-based chemotherapy for advanced breast cancer was carried out. Global (complete plus partial) response rate over time with allowance for type of drug regimen (mono- or polychemotherapy) and prior adjuvant therapies was assessed in the doxorubicin-containing arm using multivariate logistic regression analysis.

RESULTS

Twenty-nine studies published from 1975 to 1999 were retrieved for a total of 2234 women with advanced breast cancer enrolled in the doxorubicin-containing arms. There was a significant decrease in response rate to doxorubicin as first-line treatment over time that resisted adjustment for important differences in therapeutic management [odds ratio for global response = 0.89, 95% confidence interval (CI) 0.81 to 0.99].

CONCLUSIONS

Although only one drug (doxorubicin) in one clinical context (advanced breast cancer) has been analyzed, our findings support the use of double blind methodology whenever possible when assessing subjective endpoints and encourage further studies aimed at defining the clinical relevance of a wish bias in medicine.

Modulating effect of lonidamine on response to doxorubicin in metastatic breast cancer patients: results from a multicenter prospective randomized trial

Previous results from our preclinical studies have shown that lonidamine (LND) can positively modulate the antiproliferative activity of doxorubicin (DOX) on breast cancer cell lines. To evaluate the effect of LND in a clinical setting, a multicenter randomized trial was carried out on patients with advanced breast cancer. From September 1991 to July 1993, 181 patients were enrolled in the trial and received an initial treatment of DOX at 75 mg/m2 for 3 cycles. The 137 patients who reached complete remission, partial remission, or stable disease were randomized to receive either DOX alone (75 mg/m2 day 1) (arm A) or DOX plus LND (600 mg orally/day) (arm B). The patients enrolled in the two arms were fairly homogeneous in terms of major clinical characteristics. Toxicity was similar in both arms except for myalgia: WHO grade > or=2 was observed in 57% of arm B patients. Overall response rate to DOX + LND was 50% and to DOX alone 38% in evaluable patients, and 48% vs 37% in all registered patients, as determined by an intention-to-treat analysis. The differences did not reach statistical significance. Conversely, in agreement with previous findings, we observed a significant difference in response rate in the subgroup of patients with liver metastases, regardless of the extent of hepatic involvement (DOX + LND 68% vs DOX 33%, p=0.03). This observation makes LND an important tool in association with anthracyclines in the treatment of this subgroup of patients.