Recombinant human erythropoietin for anaemia in Chinese cancer patients on chemotherapy

Erythropoietin or darbepoetin for patients with cancer

BACKGROUND

Anaemia associated with cancer and cancer therapy is an important clinical factor in the treatment of malignant diseases. Therapeutic alternatives are recombinant human erythropoiesis stimulating agents (ESAs) and red blood cell transfusions.

OBJECTIVES

To assess the effects of ESAs to either prevent or treat anaemia in cancer patients.

SEARCH METHODS

This is an update of a Cochrane review first published in 2004. We searched the Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE and other databases. Searches were done for the periods 01/1985 to 12/2001 for the first review, 1/2002 to 04/2005 for the first update and to November 2011 for the current update. We also contacted experts in the field and pharmaceutical companies.

SELECTION CRITERIA

Randomised controlled trials on managing anaemia in cancer patients receiving or not receiving anti-cancer therapy that compared the use of ESAs (plus transfusion if needed).

DATA COLLECTION AND ANALYSIS

Several review authors assessed trial quality and extracted data. One review author assessed quality assessment and extracted data, a second review author checked for correctness.

MAIN RESULTS

This update of the systematic review includes a total of 91 trials with 20,102 participants. Use of ESAs significantly reduced the relative risk of red blood cell transfusions (risk ratio (RR) 0.65; 95% confidence interval (CI) 0.62 to 0.68, 70 trials, N = 16,093). On average, participants in the ESAs group received one unit of blood less than the control group (mean difference (MD) -0.98; 95% CI -1.17 to -0.78, 19 trials, N = 4,715). Haematological response was observed more often in participants receiving ESAs (RR 3.93; 95% CI 3.10 to 3.71, 31 trials, N = 6,413). There was suggestive evidence that ESAs may improve Quality of Life (QoL). There was strong evidence that ESAs increase mortality during active study period (hazard ratio (HR) 1.17; 95% CI 1.06 to 1.29, 70 trials, N = 15,935) and some evidence that ESAs decrease overall survival (HR 1.05; 95% CI 1.00 to 1.11, 78 trials, N = 19,003). The risk ratio for thromboembolic complications was increased in patients receiving ESAs compared to controls (RR 1.52, 95% CI 1.34 to 1.74; 57 trials, N = 15,498). ESAs may also increase the risk for hypertension (fixed-effect model: RR 1.30; 95% CI 1.08 to 1.56; random-effects model: RR 1.12; 95% CI 0.94 to 1.33, 31 trials, N = 7,228) and thrombocytopenia/haemorrhage (RR 1.21; 95% CI 1.04 to 1.42; 21 trials, N = 4,507). There was insufficient evidence to support an effect of ESA on tumour response (fixed-effect RR 1.02; 95% CI 0.98 to 1.06, 15 trials, N = 5,012).

AUTHORS' CONCLUSIONS

ESAs reduce the need for red blood cell transfusions but increase the risk for thromboembolic events and deaths. There is suggestive evidence that ESAs may improve QoL. Whether and how ESAs affects tumour control remains uncertain. The increased risk of death and thromboembolic events should be balanced against the potential benefits of ESA treatment taking into account each patient's clinical circumstances and preferences. More data are needed for the effect of these drugs on quality of life and tumour progression. Further research is needed to clarify cellular and molecular mechanisms and pathways of the effects of ESAs on thrombogenesis and their potential effects on tumour growth.

Erythropoietin or Darbepoetin for patients with cancer--meta-analysis based on individual patient data

BACKGROUND

Erythropoiesis-stimulating agents (ESAs) reduce anemia in cancer patients and may improve quality of life, but there are concerns that ESAs might increase mortality.

OBJECTIVES

Our objectives were to examine the effect of ESAs and identify factors that modify the effects of ESAs on overall survival, progression free survival, thromboembolic and cardiovascular events as well as need for transfusions and other important safety and efficacy outcomes in cancer patients.

SEARCH STRATEGY

We searched the Cochrane Library, Medline, Embase and conference proceedings for eligible trials. Manufacturers of ESAs were contacted to identify additional trials.

SELECTION CRITERIA

We included randomized controlled trials comparing epoetin or darbepoetin plus red blood cell transfusions (as necessary) versus red blood cell transfusions (as necessary) alone, to prevent or treat anemia in adult or pediatric cancer patients with or without concurrent antineoplastic therapy.

DATA COLLECTION AND ANALYSIS

We performed a meta-analysis of randomized controlled trials comparing epoetin alpha, epoetin beta or darbepoetin alpha plus red blood cell transfusions versus transfusion alone, for prophylaxis or therapy of anemia while or after receiving anti-cancer treatment. Patient-level data were obtained and analyzed by independent statisticians at two academic departments, using fixed-effects and random-effects meta-analysis. Analyses were according to the intention-to-treat principle. Primary endpoints were on study mortality and overall survival during the longest available follow-up, regardless of anticancer treatment, and in patients receiving chemotherapy. Tests for interactions were used to identify differences in effects of ESAs on mortality across pre-specified subgroups. The present review reports only the results for the primary endpoint.

MAIN RESULTS

A total of 13933 cancer patients from 53 trials were analyzed, 1530 patients died on-study and 4993 overall. ESAs increased on study mortality (combined hazard ratio [cHR] 1.17; 95% CI 1.06-1.30) and worsened overall survival (cHR 1.06; 95% CI 1.00-1.12), with little heterogeneity between trials (I(2) 0%, p=0.87 and I(2) 7.1%, p=0.33, respectively). Thirty-eight trials enrolled 10441 patients receiving chemotherapy. The cHR for on study mortality was 1.10 (95% CI 0.98-1.24) and 1.04; 95% CI 0.97-1.11) for overall survival. There was little evidence for a difference between trials of patients receiving different cancer treatments (P for interaction=0.42).

AUTHORS' CONCLUSIONS

ESA treatment in cancer patients increased on study mortality and worsened overall survival. For patients undergoing chemotherapy the increase was less pronounced, but an adverse effect could not be excluded.

Erythropoietin or darbepoetin for patients with cancer

BACKGROUND

Anaemia associated with cancer and cancer therapy is an important clinical factor in the treatment of malignant diseases. Therapeutic alternatives are recombinant human erythropoietin (Epo), darbepoetin (Darbepo) and red blood cell transfusions.

OBJECTIVES

The aim of this systematic review was to assess the effects of Epo or Darbepo to either prevent or treat anaemia in cancer patients.

SEARCH STRATEGY

We searched the Central Register of Controlled Trials, MEDLINE and EMBASE and other data bases. Searches were done for the periods 01/1985 to 12/2001 for the first review and 1/2002 to 04/2005 for the update. We also contacted experts in the field and pharmaceutical companies.

SELECTION CRITERIA

Randomised controlled trials on managing anaemia in cancer patients that compared the use of Epo/Darbepo (plus transfusion if needed) with observation until red blood cell transfusion was required.

DATA COLLECTION AND ANALYSIS

Several reviewers independently assessed trial quality and extracted data.

MAIN RESULTS

This update of the systematic review included a total of 57 trials with 9,353 patients. Of these, 27 trials with 3,287 adults were also included in the first Cochrane Review. Thirty trials with 6,066 patients were added during the update process. Use of Epo/Darbepo significantly reduced the relative risk of red blood cell transfusions (RR 0.64; 95% CI 0.60 to 0.68, 42 trials, n = 6,510). On average participants in the Epo/Darbepo group received one unit of blood less than the control group (WMD -1.05; 95% CI -1.32 to -0.78, 14 trials, n = 2,353). For participants with baseline haemoglobin below 12 g/dL haematological response was observed more often in participants receiving Epo/Darbepo (RR 3.43; 95% CI 3.07 to 3.84, 22 trials, n = 4,307). There was suggestive evidence that Epo/Darbepo may improve Quality of Life (QoL). The relative risk for thrombo embolic complications was increased in patients receiving Epo/Darbepo compared to controls (RR 1.67, 95% CI 1.35 to 2.06; 35 trials, n = 6,769). Uncertainties remain whether and how Epo/Darbepo effects tumour response (fixed effect RR 1.12; 95% CI 1.01 to 1.23, 13 trials, n = 2,833; random effects: RR 1.09; 95% CI 0.94 to 1.26) or overall survival (unadjusted and adjusted data: HR 1.08; 95% CI 0.99 to 1.18; 42 trials, n = 8,167).

AUTHORS' CONCLUSIONS

There is consistent evidence that administration of Epo/Darbepo reduces the relative risk for blood transfusions and the number of units transfused in cancer patients. For patients with baseline haemoglobin below 12 g/dL (mild anaemia) there is strong evidence that Epo/Darbepo improves haematological response. There is suggestive evidence that Epo/Darbepo may improve QoL. However, there is strong evidence that Epo/Darbepo increases the relative risk for thrombo embolic complications. Whether and how Epo/Darbepo effects tumour response and overall survival remains uncertain.