Erythropoietin, uncertainty principle and cancer related anaemia

The prognostic impact of decreased pretreatment haemoglobin level on the survival of patients with lung cancer: a systematic review and meta-analysis

BACKGROUND

Many studies have reported the prognostic value of haemoglobin level for cancers. Whereas the prognostic impact of decreased pretreatment haemoglobin level on the survival of patients with lung cancer remains controversial, herein, a systematic review and meta-analysis were conducted to investigate whether a decreased haemoglobin level before treatment is a significant predictor of survival in patients with lung cancer.

METHODS

We performed a systematic review and meta-analysis of observational studies to evaluate the prognostic impact of a decreased haemoglobin level on the survival of patients with lung cancer. Relevant studies were retrieved from databases including PubMed, Embase, Web of Science and the Cochrane Library. Reference lists were hand-searched for potentially eligible studies. The Newcastle-Ottawa scale was used to assess the quality of included studies. Observational studies were included if they provided sufficient information for the extraction of the pooled hazard ratios (HR) and 95% confidence intervals (95% CI) for overall survival, disease-free survival, relapse-free survival, progression-free survival, event-free survival and time to progression. Subgroup analysis, meta-regression and sensitivity analyses were applied to explain the heterogeneity.

RESULTS

Fifty-five articles involving a total of 22,719 patients were obtained to evaluate the correlation between haemoglobin level and survival. The results indicated that decreased haemoglobin level was significantly associated with poor overall survival of patients with lung cancer (HR 1.51, 95% CI 1.42-1.61), both in non-small cell lung cancer (HR 1.57, 95% CI 1.44-1.72) and in small cell lung cancer (HR 1.56, 95% CI 1.21-2.02). We also found that the lower the haemoglobin level, the shorter was the overall survival of patients with lung cancer (HR 1.11, 95% CI 1.06-1.16). However, the relationship between decreased haemoglobin and relapse-free survival was not significant (HR 1.37, 95% CI 0.91-2.05).

CONCLUSION

A decreased pretreatment haemoglobin level among patients with lung cancer is a prognostic factor of poor survival that can serve as an important indicator in survival prediction, risk stratification and treatment selection. In clinical practice, more attention should be paid to monitoring pretreatment haemoglobin levels among patients with lung cancer.

Industry sponsorship and research outcome

BACKGROUND

Clinical research affecting how doctors practice medicine is increasingly sponsored by companies that make drugs and medical devices. Previous systematic reviews have found that pharmaceutical-industry sponsored studies are more often favorable to the sponsor's product compared with studies with other sources of sponsorship. A similar association between sponsorship and outcomes have been found for device studies, but the body of evidence is not as strong as for sponsorship of drug studies. This review is an update of a previous Cochrane review and includes empirical studies on the association between sponsorship and research outcome.

OBJECTIVES

To investigate whether industry sponsored drug and device studies have more favorable outcomes and differ in risk of bias, compared with studies having other sources of sponsorship.

SEARCH METHODS

In this update we searched MEDLINE (2010 to February 2015), Embase (2010 to February 2015), the Cochrane Methodology Register (2015, Issue 2) and Web of Science (June 2015). In addition, we searched reference lists of included papers, previous systematic reviews and author files.

SELECTION CRITERIA

Cross-sectional studies, cohort studies, systematic reviews and meta-analyses that quantitatively compared primary research studies of drugs or medical devices sponsored by industry with studies with other sources of sponsorship. We had no language restrictions.

DATA COLLECTION AND ANALYSIS

Two assessors screened abstracts and identified and included relevant papers. Two assessors extracted data, and we contacted authors of included papers for additional unpublished data. Outcomes included favorable results, favorable conclusions, effect size, risk of bias and whether the conclusions agreed with the study results. Two assessors assessed risk of bias of included papers. We calculated pooled risk ratios (RR) for dichotomous data (with 95% confidence intervals (CIs)).

MAIN RESULTS

Twenty-seven new papers were included in this update and in total the review contains 75 included papers. Industry sponsored studies more often had favorable efficacy results, RR: 1.27 (95% CI: 1.17 to 1.37) (25 papers) (moderate quality evidence), similar harms results RR: 1.37 (95% CI: 0.64 to 2.93) (four papers) (very low quality evidence) and more often favorable conclusions RR: 1.34 (95% CI: 1.19 to 1.51) (29 papers) (low quality evidence) compared with non-industry sponsored studies. Nineteen papers reported on sponsorship and efficacy effect size, but could not be pooled due to differences in their reporting of data and the results were heterogeneous. We did not find a difference between drug and device studies in the association between sponsorship and conclusions (test for interaction, P = 0.98) (four papers). Comparing industry and non-industry sponsored studies, we did not find a difference in risk of bias from sequence generation, allocation concealment, follow-up and selective outcome reporting. However, industry sponsored studies more often had low risk of bias from blinding, RR: 1.25 (95% CI: 1.05 to 1.50) (13 papers), compared with non-industry sponsored studies. In industry sponsored studies, there was less agreement between the results and the conclusions than in non-industry sponsored studies, RR: 0.83 (95% CI: 0.70 to 0.98) (six papers).

AUTHORS' CONCLUSIONS

Sponsorship of drug and device studies by the manufacturing company leads to more favorable efficacy results and conclusions than sponsorship by other sources. Our analyses suggest the existence of an industry bias that cannot be explained by standard 'Risk of bias' assessments.

Lessons from the past: Long-term safety and survival outcomes of a prematurely terminated randomized controlled trial on prophylactic vs. hemoglobin-based administration of erythropoiesis-stimulating agents in patients with chemotherapy-induced anemia

Prophylactic erythropoiesis-stimulating agent (ESA) administration for chemotherapy-induced anemia (CIA) is not supported by current guidelines. Long-term follow-up of patients WHO had been treated with ESA for CIA in the past may provide useful information. In 2002, we undertook a prospective, randomized phase III trial of prophylactic vs. hemoglobin (Hb)-based (threshold: 11 mg/dl) ESA administration in patients with solid tumors and CIA. ESA administration FOR CIA was permanently suspended in 2007 in view of published data at that time, while patient surveillance continued. Among 630 evaluable patients, 38.6% were male, 50.9% had advanced cancer at diagnosis, 40.6% had Hb levels <12 mg/dl at baseline and 47.9% received ESA prophylactically (1:1 randomization). The major tumor types included colorectal (36.0%), breast (20.6%), non-prostate genitourinary (11.0%) and lung CANCER (8.4%). After a median follow-up of 85.4 months, 358 patients had relapsed and 380 had succumbed to the disease. Patients in the prophylactic ESA group (GROUP A; experimental arm), as compared with those in the Hb-based group (GROUP B; iron supplementation alone), exhibited A significantly more prominent increase in median Hb levels, particularly in the subset of patients with non-metastatic disease (two-sided P<0.01) among patients receiving chemotherapy for advanced cancer, those who received ESAs prophylactically exhibited a lower incidence of CIA (all grades: P=0.014, grades 3-4: P=0.034) and fatigue (all grades: P<0.001, grades 3-4: P=0.055), but a higher rate of a composite outcome encompassing all thrombosis-related events (all grades: P=0.043, grades 3-4: P=0.099). These differences were less prominent in the group of patients who received adjuvant treatment. There were no significant differences in overall mortality and relapse/progression rates between the two groups. therefore, prophylactic, compared with Hb-based, administration of ESAs for CIA in patients with solid tumors, was found to be associated with a significantly lower incidence of anemia and fatigue, but with a marginally higher rate of thrombosis-related adverse events, particularly in patients receiving first-line chemotherapy for advanced cancer.

Exploring redundant research into the effect of tranexamic acid on surgical bleeding: further analysis of a systematic review of randomised controlled trials

OBJECTIVES

We examined whether apparent redundancy in a cumulative meta-analysis of trials is justified by concern about bias, random error or generalisability of the results.

DESIGN

Cumulative meta-analysis, risk of bias assessment, trial sequential analysis, description of study participants over time and a review of rationales for conducting trials.

DATA SOURCE

126 randomised trials included in a systematic review assessing of tranexamic acid on blood transfusion in surgery.

RESULTS

The cumulative meta-analysis including all trials shows that the pooled estimate first reached statistical significance after the second trial in 1993. When the analysis was limited to the 38 high-quality trials and adjusted to account for potential systematic and random errors, the uncertainty was resolved after the 22nd trial in 2008. When the analysis was restricted to the two high-quality, prospectively registered trials, the cumulative z-curve crossed p=0.05 but not the monitoring boundary, suggesting an early potentially spurious statistically significant result. As precision of the pooled estimate increased, the number of trials initiated increased, although trial activity appeared to move to other surgery types. Most (62%) reports cited at least one systematic review. Of 118 reports examined, concern about generalisability was the reason for initiating the trial in 60%. Other reasons were to address a question other than the effect on bleeding (26%) and to confirm previously observed results (4%). Unawareness of previous research was apparent in 4% trials, while the rationale was unclear in 3%.

CONCLUSIONS

Our results indicate that poor quality is a more important cause of redundant research than the failure to review existing evidence. Concerns about generalisability of results is the main motivation for new trials. Contrary to previous claims, our results suggest that systematic reviews showing treatment effects can stimulate an increase in trial activity rather than reduce it.

Complex gastroschisis is a different entity to simple gastroschisis affecting morbidity and mortality-a systematic review and meta-analysis

BACKGROUND

Comparison of the outcome of newborns with simple (sGS) and complex gastroschisis (cGS: gastroschisis with atresia, necrosis, perforation or volvulus).

MATERIALS AND METHODS

We conducted a systematic database search, quality assessment and meta-analyzed relevant articles which evaluated the mortality and morbidity of newborns with cGS versus sGS. Risk ratios (RR) with 95% confidence interval (CI) were reported for categorical data, and the mean difference (MD) was calculated for continuous data. Pooled estimates of RR and MD were computed using generic inverse variance and a random-effects model.

RESULTS

Of 19 identified reports, 13 eligible studies were included. The mortality of infants with cGS (16.67%) was significantly higher than sGS (2.18%, RR: 5.39 [2.42, 12.01], p<0.0001). Significantly different outcome was found for the following parameters: Infants with cGS are started on enteral feedings later and they take longer to full enteral feedings with a subsequent longer duration of parenteral nutrition. Their risk of sepsis, short bowel syndrome and necrotizing enterocolitis is higher. They stay longer in hospital and are more likely to be sent home with enteral tube feedings and parenteral nutrition.

DISCUSSION

Occurring in 17% of infants born with gastroschisis, complex gastroschisis is associated with a significantly increased morbidity and mortality. More research should be focused on this special subgroup of patients, not only on postnatal management, but additionally directing efforts to improve diagnosing and predicting complex gastroschisis prenatally as well as implement any probable fetal intervention to alleviate its disastrous outcome.

Accumulating research: a systematic account of how cumulative meta-analyses would have provided knowledge, improved health, reduced harm and saved resources

Background

“Cumulative meta-analysis” describes a statistical procedure to calculate, retrospectively, summary estimates from the results of similar trials every time the results of a further trial in the series had become available. In the early 1990s, comparisons of cumulative meta-analyses of treatments for myocardial infarction with advice promulgated through medical textbooks showed that research had continued long after robust estimates of treatment effects had accumulated, and that medical textbooks had overlooked strong, existing evidence from trials. Cumulative meta-analyses have subsequently been used to assess what could have been known had new studies been informed by systematic reviews of relevant existing evidence and how waste might have been reduced.

Methods and Findings

We used a systematic approach to identify and summarise the findings of cumulative meta-analyses of studies of the effects of clinical interventions, published from 1992 to 2012. Searches were done of PubMed, MEDLINE, EMBASE, the Cochrane Methodology Register and Science Citation Index. A total of 50 eligible reports were identified, including more than 1,500 cumulative meta-analyses. A variety of themes are illustrated with specific examples. The studies showed that initially positive results became null or negative in meta-analyses as more trials were done; that early null or negative results were over-turned; that stable results (beneficial, harmful and neutral) would have been seen had a meta-analysis been done before the new trial; and that additional trials had been much too small to resolve the remaining uncertainties.

Conclusions

This large, unique collection of cumulative meta-analyses highlights how a review of the existing evidence might have helped researchers, practitioners, patients and funders make more informed decisions and choices about new trials over decades of research. This would have led to earlier uptake of effective interventions in practice, less exposure of trial participants to less effective treatments, and reduced waste resulting from unjustified research.

Combining data from multiple studies: an introduction to meta-analysis in paediatric surgery

Evidence-based medicine mandates that the best available evidence should be used to inform clinical decision making. Though there is a paucity of high level evidence within paediatric surgery generally, randomised controlled trials in this age group have become more frequent recently. This article reviews the statistical basis behind effective systematic reviews and meta-analysis for the practising clinician and is based on an invited lecture to the Experimental Research Club within the BAPS/EUPSA Congress, Rome, Italy, June 2012.

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.

Management of anemia in cancer patients

Cancer-related anemia adversely affects quality of life and is associated with reduced overall survival. The correction of anemia in cancer patients has the potential to improve treatment efficacy and increase survival. A large number of studies demonstrate that treatment of anemia in cancer patients using erythropoiesis-stimulating agents (ESAs) significantly increases hemoglobin levels, decreases transfusion requirements and improves quality of life, predominantly by reducing fatigue. Some data on the use of ESAs in cancer patients indicate an increased risk of thromboembolic events and a possibly increased risk of mortality. However, there is ample evidence that when ESAs are used within current guidelines, they are valuable and safe drugs for the treatment of anemia in patients receiving radiotherapy and/or chemotherapy. There are increasing data from prospective, randomized trials demonstrating better responses to ESAs with the concurrent use of iron. Blood transfusions are also helpful in the management of anemia in cancer patients, especially when there is a need for immediate increases in hemoglobin levels. In this article, we discuss recent aspects relating to treatment modalities for anemia in cancer patients.

Ten years of meta-analyses on erythropoiesis-stimulating agents in cancer patients

BACKGROUND

Since erythropoiesis-stimulating agents (ESAs) were licensed in 1993, more than 70 randomized controlled trials and more than 20 meta-analyses and systematic reviews on their effectiveness were conducted. Here, we present a systematic review on the meta-analyses of trials evaluating ESAs in cancer patients.

METHODS

We included all published meta-analyses of at least five randomized controlled trials that evaluated the effects of ESAs versus control in patients with any type of cancer or myelodysplastic syndrome.

RESULTS

We included a total of 23 systematic reviews and meta-analyses (16 literature based and 7 based on individual patient data (IPD)) that assessed several outcomes. All 12 meta-analyses reporting on transfusion risks demonstrated that ESAs significantly reduce the risk of transfusions. Eleven meta-analyses (nine based on published data and two on IPD) evaluated thrombovascular events. An increased risk of thrombovascular events was observed in all but two meta-analyses (relative risks (RRs) ranging from 1.57 to 1.69). However, potential reporting and publication bias as well as detection bias call for a cautious interpretation of these results. Survival and mortality were evaluated in 18 meta-analyses, with the observed effect changing over time. While meta-analyses on studies conducted before 2002 showed beneficial effects of ESAs on survival, contrary results, i.e. worsened survival, was seen in meta-analyses including more recent studies.

DISCUSSION

The results from several meta-analyses show that ESAs in cancer patients reduce the risk for red blood cell transfusions and increase the risk for thrombovascular events and mortality. The effect of ESAs on mortality risk in patients receiving chemotherapy remains unclear. In clinical practice, the benefits and risks of ESAs should be carefully considered and decisions should be made based on each patient's situation and preferences.

Erythropoietin in cancer patients: pros and cons

PURPOSE OF REVIEW

Anaemia is a frequent complication of cancer. Recently, some concerns have appeared regarding the safety of erythropoiesis-stimulating agents (ESAs) for the treatment of anaemia in cancer patients. The current review will analyse the main arguments in favour of erythropoietin (EPO), as well as those against EPO in chemotherapy-induced anaemia and in cancer-related anaemia. The principal concerns are tumour progression, increased mortality and the risk of venous thromboembolic events (VTEs). Recent meta-analyses have come to divergent conclusions.

RECENT FINDINGS

Several meta-analyses have reviewed the data regarding VTEs, EPO receptors on tumours and tumour progression as well as mortality.

SUMMARY

As of now, ESAs should only be used within the indications as given in the various guidelines.

Anemia management in oncology and hematology

Anemia is frequent in cancer patients and its incidence increases with chemotherapy. The probability of requiring transfusions also increases with chemotherapy. Anemia negatively impacts survival and accentuates fatigue in cancer patients. Cancer promotes inflammatory cytokine production, which suppresses erythropoiesis and erythropoietin (EPO) production. Erythropoiesis-stimulating agents (ESAs) improve erythropoiesis and reduce transfusion needs in anemic cancer patients receiving chemotherapy. However, meta-analyses have shown an increased risk of thromboembolic (TE) events with ESA use during chemotherapy, but not increased on-study mortality or reduced overall survival. Three reasons have been proposed to explain why ESAs might have adverse effects in anemic cancer patients: tumor progression due to stimulation of tumor cell EPO receptors; increased risk of TE; and reduced survival. However, erythropoietin is not an oncogene, nor is the EPO receptor. It has also been demonstrated that erythropoietin does not stimulate tumor proliferation. Increased TE risk associated with ESAs is probably a consequence of increased blood viscosity due to excessive RBC mass elevation with concomitant plasma volume contraction, nitric oxide scavenging, and endothelial cell activation. Increased ESA dosing may also impact survival negatively because EPO contracts the plasma volume and stimulates inflammatory cytokine production independently of increasing erythropoiesis. Furthermore, transfusions themselves are associated with an increase in TE and plasma volume contraction, and these events are potentiated when ESAs are given with transfusions. An update on the management of anemia in oncology, the potential adverse events of ESAs, the benefits and risks of transfusions, and QoL are discussed in this paper.

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.

The erythropoietin receptor in normal and cancer tissues

The hormone erythropoietin (EPO) is essential for the survival, proliferation and differentiation of the erythrocytic progenitors. The EPO receptor (EPO-R) of erythrocytic cells belongs to the cytokine class I receptor family and signals through various protein kinases and STAT transcription factors. The EPO-R is also expressed in many organs outside the bone marrow, suggesting that EPO is a pleiotropic anti-apoptotic factor. The controversial issue as to whether the EPO-R is functional in tumor tissue is critically reviewed. Importantly, most studies of EPO-R detection in tumor tissue have provided falsely positive results because of the lack of EPO-R specific antibodies. However, endogenous EPO appears to be necessary to maintain the viability of endothelial cells and to promote tumor angiogenesis. Although there is no clinical proof that the administration of erythropoiesis stimulating agents (ESAs) promotes tumor growth and mortality, present recommendations are that (i) ESAs should be administered at the lowest dose sufficient to avoid the need for red blood cell transfusions, (ii) ESAs should not be used in patients with active malignant disease not receiving chemotherapy or radiotherapy, (iii) ESAs should be discontinued following the completion of a chemotherapy course, (iv) the target Hb should be 12 g/dL and not higher and (v) the risks of shortened survival and tumor progression have not been excluded when ESAs are dosed to target Hb <12 g/dL.

Risks and benefits of erythropoiesis-stimulating agents in cancer management

Anemia is frequently diagnosed in patients with cancer and its treatment is an important clinical problem. The deficiency in red blood cells (RBCs) can be a debilitating problem, and anemia correlates with poor performance status, deteriorates quality of life, and may negatively influence the prognosis of cancer patients. The development of recombinant human erythropoietins (rhEPO) provides a therapeutic option in patients with mild to moderate anemia. However, clinical experience demonstrates that more than half of anemic cancer patients are not treated. There is clear evidence that rhEPO reliably increases haemoglobin (Hb) levels in patients suffering from cancer-related or treatment-associated anemia. The dosing and management of these patients should strictly follow evidence-based guidelines of the clinical societies, as well as the manufacturer's recommendations. Furthermore, treatment of patients beyond the correction of anemia must be regarded as potentially harmful and should only be conducted in an experimental clinical setting. In this review, recently published recommendations and standards for the use of rhEPO will be discussed.

Cancer-related anemia and recombinant human erythropoietin--an updated overview

For cancer patients, anemia can be a debilitating problem that negatively influences their overall quality of life and worsens their prognosis. The condition is caused either by the cancer itself or by cytotoxic treatment. Anemia is the primary indication for transfusion of red blood cells, but the development of recombinant human erythropoietins (epoetins) provides an alternative to red blood cell transfusions. Treatment with epoetins has been shown to reduce transfusion rates and increase hemoglobin response. There is some evidence that epoetins improve quality of life. It remains unclear, however, whether erythropoietin affects tumor growth and survival, and this area requires further investigation. Data from clinical trials suggest that erythropoietin increases the risk of thromboembolic complications. In the management of anemic patients, physicians should follow closely the dosing recommendations in products' package inserts or the ASCO/American Society of Hematology guidelines. Treatment of patients beyond the correction of anemia, however, has to be regarded as experimental and is potentially harmful, so should only be conducted in clinical trials.

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.

Recombinant human erythropoietins and cancer patients: updated meta-analysis of 57 studies including 9353 patients

This is an updated systematic review of 57 trials and 9353 cancer patients from articles, abstracts, and reports published between January 1, 1985, and April 30, 2005, on the effects of epoetin alfa and beta (i.e., epoetin) and darbepoetin alfa (i.e., darbepoetin). We included randomized controlled trials comparing epoetin or darbepoetin plus red blood cell transfusion with red blood cell transfusion alone for prophylaxis or treatment of anemia in cancer patients with or without concurrent antineoplastic therapy. The Cochrane Library, MEDLINE, EMBASE, and conference proceedings were searched. Effect estimates and 95% confidence intervals (CIs) were calculated with fixed-effects models. Treatment with epoetin or darbepoetin statistically significantly reduced the risk for red blood cell transfusions (relative risk [RR] = 0.64, 95% CI = 0.60 to 0.68; 42 trials and 6510 patients) and improved hematologic response (RR = 3.43, 95% CI = 3.07 to 3.84; 22 trials and 4307 patients). Treatment with epoetin or darbepoetin increased the risk of thrombo-embolic events (RR = 1.67, 95% CI = 1.35 to 2.06; 35 trials and 6769 patients). Uncertainties remain as to whether and how epoetin or darbepoetin affects overall survival (hazard ratio = 1.08, 95% CI = 0.99 to 1.18; 42 trials and 8167 patients). Caution is advised when using epoetin or darbepoetin in combination with thrombogenic chemotherapeutic agents or for cancer patients who are at high risk for thrombo-embolic events.

Retrospective observational study of patients with chemotherapy-related anemia receiving erythropoietic agents

OBJECTIVE

Epoetin alfa (EPO) and darbepoetin alfa (DARB) are approved for the treatment of chemotherapy-related anemia (CRA) in patients with nonmyeloid malignancies. This study examined dosing and hematologic outcomes with these agents in community oncology clinics.

METHODS

Medical charts were abstracted retrospectively for 1005 patients (527 EPO, 478 DARB) with CRA (hemoglobin [Hb] < or = 11 g/dL) who received EPO or DARB at 10 U.S. oncology clinics between January 2002 and March 2003.

MAIN OUTCOME MEASURES

Outcome measures included dose and frequency of erythropoietic therapy, change in Hb at 4, 8, and 12 weeks after initiation of therapy, and transfusion of packed red blood cells.

RESULTS

Baseline characteristics were generally similar between groups. Most EPO-treated patients received EPO once weekly, but 25% received EPO every 2-3 weeks, with 40,000 U the predominant dose. DARB was usually given every 1-2 weeks in doses ranging from 200-400 mcg/injection. Mean treatment duration was relatively short (< 8 weeks) in both groups, with a similar number of Hb determinations and similar incidence of red blood transfusion between groups. Hb increased from baseline in the EPO and DARB groups at 4 weeks (0.99 vs. 0.69 g/dL, p = 0.003), 8 weeks (1.39 vs. 1.06 g/dL, p = 0.011), and 12 weeks (1.43 vs. 1.11 g/dL, p = 0.055). Early Hb response (> or = 1 g/dL increase by 4 weeks) was more common with EPO than DARB (48% vs. 38%, p = 0.008).

CONCLUSIONS

EPO was superior to DARB for early hematologic outcomes in patients with CRA in community oncology clinics. Retrospective data collection and relative inexperience with DARB at the time of the study may limit the generalization of these results. Randomized, controlled trials comparing EPO and DARB are warranted.

The impact of weekly dosing of epoetin alfa on the haematological parameters and on the quality of life of anaemic cancer patients

The aim of this study was to evaluate the effectiveness and the impact of once-weekly administration of epoetin alfa (Ea) on the management of anaemia and on the quality of life (QOL) of cancer patients receiving chemotherapy. Eighty cancer patients with life expectancy > or = 24 weeks and haemoglobin (Hb) levels < 10.5 g/dL were studied. After an initial screening of patients' demographic and clinical characteristics, Ea 40000 U once a week was administered over a period of 4 months. In case of patients with Hb level exceeding > 14 g/dL or in case of non-response, the dosage was reconsidered. Every month, data regarding Hb levels, clinical variations, changes in the chemotherapy regimen and transfusion use since the last study visit, were evaluated. The Linear Analogue Scale Assessment scale was used for the evaluation of the QOL. The readmissions to hospital rates (P < 0.002) and the transfusion use rates (P < 0.003) were significantly decreased comparatively with baseline. A mean increase from baseline to the final Hb level (P < 0.001) was established, as well as a significant improvement in the functional ability, energy and in the overall QOL (P < 0.001). In conclusion, the treatment of cancer patients with Ea once-weekly is effective and safe, improving their haematological parameters and QOL.

Recombinant Human Erythropoietin and Overall Survival in Cancer Patients: Results of a Comprehensive Meta-analysis

BACKGROUND

Anemia associated with cancer and cancer therapy is an important clinical and economic factor in the treatment of malignant diseases.

METHODS

We conducted a systematic literature review to assess the efficacy of erythropoietin to prevent or treat anemia in cancer patients with regard to red blood cell transfusions, hematologic response, adverse events, and overall survival. We searched the Cochrane Library, Medline, EMBASE, and other databases for relevant articles published from January 1985 to December 2001. We included all randomized controlled trials that compared the use of recombinant human erythropoietin (plus transfusion, if needed) with no erythropoietin treatment (plus transfusion, if needed). Relative risks (RRs) and 95% confidence intervals (CIs) were calculated under a fixed-effects model. Clinical and statistical heterogeneity were examined with sensitivity analyses and meta-regression. Statistical tests for effect estimates were two-sided.

RESULTS

We identified 27 trials involving 3287 adult patients. Patients treated with erythropoietin had a lower relative risk of having a blood transfusion than untreated patients (RR = 0.67, 95% CI = 0.62 to 0.73). Erythropoietin-treated patients with baseline hemoglobin levels lower than 10 g/dL were more likely to have a hematologic response than untreated patients (RR = 3.60, 95% CI = 3.07 to 4.23). The relative risk for thromboembolic complications after erythropoietin treatment was not statistically significantly increased (RR = 1.58, 95% CI = 0.94 to 2.66) compared with that of untreated patients. There is suggestive but inconclusive evidence that erythropoietin may improve overall survival (adjusted data: hazard ratio [HR] = 0.81, 95% CI = 0.67 to 0.99; unadjusted data: HR = 0.84, 95% CI = 0.69 to 1.02).

CONCLUSIONS

Erythropoietin treatment may reduce the risk for blood transfusions and improve hematologic response in cancer patients. However, our favorable survival outcome is in contrast to two large (N = 351 and 939) recently published randomized controlled trials in which erythropoietin-treated patients had statistically significantly worse survival than untreated patients. Possible reasons for the disparity with our results include differences in study population and design, higher target hemoglobin levels and higher risk of thromboembolic complications, and concerns that erythropoietin may stimulate tumor growth.

Prior red blood cell transfusions in cancer patients increase the risk of subsequent transfusions with or without recombinant human erythropoietin management

Cancer patients often receive transfusions when their hemoglobin concentration falls to dangerously low levels due to chemotherapy or due to the disease itself. The availability of recombinant human erythropoietin (rHuEPO) has significantly reduced transfusion frequencies in cancer patients. However, the predictability of transfusions prior to the use of rHuEPO for future transfusions has not been evaluated. Data from five randomized, double-blind, placebo-controlled trials in cancer patients receiving chemotherapy and epoetin alfa were utilized to calculate the relative risk of subsequent transfusions in patients who were pretransfused. A meta-analysis with patient-level data was used to assess predictors of transfusion. Baseline data from an open-label study were used to compare quality-of-life (QOL) parameters between previously transfused and transfusion-naive patients. The mean relative risks (RR) of exposure to additional transfusion for pretransfused patients on placebo or epoetin alfa were 2.14 (95% confidence interval [CI]: 1.73, 2.65) and 2.51 (95% CI: 1.92, 3.27), respectively, compared with nontransfused patients. Data from the meta-analysis of patients on epoetin alfa showed that pretransfusion was the most significant predictor for subsequent transfusions (parameter estimate = -1.2628, p < 0.0001 from Logistic Regression Analysis). While epoetin alfa was similarly effective in reducing transfusion risks for patients with or without pretransfusions (compared with placebo), those who were pretransfused were more than twice as likely to be subsequently transfused, compared with those not pretransfused. QOL was significantly worse for pretransfused patients than for nontransfused patients, as measured by the Functional Assessment of Cancer Therapy -Anemia and the Linear Analogue Scale Assessment QOL instruments. The results suggest that transfusions prior to epoetin alfa therapy increase the risk of future transfusions, and early treatment with epoetin alfa might reduce the risk of subsequent transfusions.

EORTC guidelines for the use of erythropoietic proteins in anaemic patients with cancer

Anaemia is frequently diagnosed in patients with cancer, yet it is difficult to identify a single cause due to its multifactorial aetiology. We conducted a systematic literature review (1996-2003) to produce evidence-based guidelines on the use of erythropoietic proteins in anaemic patients with cancer (see ). Level I evidence exists for a positive impact of erythropoietic proteins on haemoglobin (Hb) levels when administered to patients with chemotherapy-induced anaemia or anaemia of chronic disease, when used to prevent cancer anaemia, in patients undergoing cancer surgery and following allogeneic bone marrow transplantation. The Hb level at which erythropoietic protein therapy should be initiated is difficult to determine as it varied between studies; a large number of Level I studies in patients with chemotherapy-induced anaemia or anaemia of chronic disease enrolled patients with a Hb concentration </=105 g/L, but none compared the effect of different baseline Hb levels on the response to treatment. Similarly, several studies defined the target Hb concentration as 120-130 g/L following treatment with erythropoietic proteins, but none specifically addressed the correlation between target Hb level and clinical benefit in a randomised fashion. Level I evidence shows that red blood cell (RBC) transfusion requirements are significantly reduced with erythropoietic protein therapy in patients with chemotherapy-induced anaemia or when used to prevent cancer anaemia (approximately 20% reduction compared with controls). We found indirect Level I and III evidence that patients with chemotherapy-induced anaemia or anaemia of chronic disease initially classified as non-responders to standard doses proceed to respond to treatment following a dose increase (absolute increases in response rate ranged from 8% to 18%). However, none of these studies examined the effect on response rates of a longer treatment period at the lower dose, or performed a randomised comparison of a dose increase versus an unchanged dose. There is Level I evidence to show that quality-of-life (QOL) is significantly improved in patients with chemotherapy-induced anaemia and in those with anaemia of chronic disease, particularly in patients achieving a Hb response to erythropoietic protein therapy. There are insufficient data to determine the effect on survival following treatment with erythropoietic proteins in conjunction with chemotherapy or radiotherapy. There is Level I evidence that dosing of erythropoietic proteins less frequently than three times per week (TIW) is efficacious when used to treat chemotherapy-induced anaemia or prevent cancer anaemia. There is Level III evidence that initial doses of erythropoietic proteins considered to be higher than current standard practice produce higher haematological responses in patients with chemotherapy-induced anaemia or anaemia of chronic disease. Level I evidence demonstrates that several baseline patient parameters (e.g., low endogenous erythropoietin [EPO] concentration, age <60 years, Hb concentration >/=90 g/L) impact upon the response to erythropoietic proteins when used to treat chemotherapy-induced anaemia or prevent cancer anaemia. Evidence indicates that endogenous EPO concentration impacts on response in patients with lymphoproliferative malignancies, but is not a valid parameter in patients with solid tumours. There is Level I evidence that fixed doses of erythropoietic proteins can be used at the start of therapy to treat patients with chemotherapy-induced anaemia, but maintenance doses should be titrated individually. There is no evidence that pure red cell aplasia (PRCA) occurs following treatment with erythropoietic proteins in patients with chemotherapy-induced anaemia or when used prophylactically in patients with cancer. There is Level I evidence that the risk of thromboembolic events and hypertension are slightly elevated in patients with chemotherapy-induced anaemia receiving erythropoietic proteins. Level I evidence supports the effectiveness of erythropoietic proteins to prevenroteins to prevent anaemia in non-anaemic cancer patients receiving chemotherapy or radiotherapy or in those undergoing cancer surgery. However, these are non-licensed indications and we do not currently recommend the prophylactic use of erythropoietic proteins to prevent anaemia in patients who have normal Hb values at the start of treatment. Additional trials are warranted, especially on the issues of iron replacement and cost-effectiveness of erythropoietic protein therapy, as well as on tumour response/progression and survival.

Management of paraneoplastic syndromes in lung cancer

Paraneoplastic syndromes are common complications of lung cancer. Although most frequently associated with advanced disease, paraneoplastic syndromes may also occur at early stages. Occasionally, the paraneoplastic syndrome may be the presenting symptom of lung cancer. For most paraneoplastic syndromes, the best treatment is to treat the underlying malignancy. However, in many cases, treatment of moderate efficacy or urgent therapy is required. Specific recommendations for the management of the most common paraneoplastic syndromes, including cachexia, hypercalcemia, and hyponatremia, are provided.

Clinical and economic impact of epoetins in cancer care

Anaemia develops in most patients undergoing cancer therapy and invariably induces fatigue, which is a major determinant of QOL. Blood transfusions are reserved for patients with severe anaemia, since blood is a scarce resource and provides a short-lived benefit. Epoetins are recombinant proteins capable of alleviating therapy-related anaemia in 40-60% of cancer patients. The number of patients needed to be treated with epoetins to avoid the transfusion of one unit of blood ranges from 2.6 to 5.2; however, the absolute risk reduction depends on patients' characteristics and dose-escalation. The ratio between acquisition costs of epoetins and blood transfusion requirement is very high; thus, many thousands of dollars needs to be spent on epoetins to save 1 blood unit. Despite this, epoetins have been widely adopted by industrialised countries, where cancer patients are about 2% of the total population. The resulting budget impact of epoetins can be calculated at about 10% of the overall direct cost for cancer care, and it is expected to continue growing by about 20% each year, due to the expanding cancer population and the intensification of cancer therapies. The economic burden of epoetins needs to be weighed against the improvement of patients' QOL and society's willingness to pay for a non-life-saving therapy. All published economic evaluations of epoetins invariably report that this supportive therapy is not cost effective. Society should be made aware of the opportunity cost of treatments and should be allowed to elicit preferences for healthcare interventions and prioritisation criteria. In the near future we expect that a wider range of epoetins, drug patent expiry, a more appropriate patient selection criteria and an improved dosage schedule may help increase the efficiency of cancer-related anaemia management.

Effect of haemopoietic growth factors on cancer cell lines and their role in chemosensitivity

The recombinant growth factors (GFs) erythropoietin (Epo) and granulocyte-macrophage colony stimulating factor (GM-CSF) have important roles in the management of cancer patients. However, the effects of these GFs at a cellular level are not well understood. We examined the effect of GFs alone, and in combination with cytotoxic chemotherapy, in a panel of seven cell lines. Flow cytometric analysis showed varying levels of receptor expression, which correlated with phosphorylated MAPK expression. Additionally, there were also concomitant increases in BCL-2 protein levels in those cells with high levels of MAPK activation. Although culturing cells with Epo or GM-CSF did not alter cell viability by themselves, GF pretreatment in cell lines expressing higher receptor levels resulted in a reduced magnitude of cell kill following exposure to cytotoxic IC50 concentrations of cisplatin. Subsequent co-culture with either the MEK inhibitor U0126 or the GM-CSF antagonist E21R negated this induced resistance to cytotoxic chemotherapy, confirming the importance of the GF receptor as well as MAPK in mediating these effects. These results suggest that the use of GFs during chemotherapy may be detrimental in those cancers expressing higher levels of the specific receptor. Conversely, our results also suggest that GFs are safe to use in chemotherapeutic regimens if the cancer cells do not overexpress the particular receptor.

Choosing a control intervention for a randomised clinical trial

BACKGROUND

Randomised controlled clinical trials are performed to resolve uncertainty concerning comparator interventions. Appropriate acknowledgment of uncertainty enables the concurrent achievement of two goals : the acquisition of valuable scientific knowledge and an optimum treatment choice for the patient-participant. The ethical recruitment of patients requires the presence of clinical equipoise. This involves the appropriate choice of a control intervention, particularly when unapproved drugs or innovative interventions are being evaluated.

DISCUSSION

We argue that the choice of a control intervention should be supported by a systematic review of the relevant literature and, where necessary, solicitation of the informed beliefs of clinical experts through formal surveys and publication of the proposed trial's protocol.

SUMMARY

When clinical equipoise is present, physicians may confidently propose trial enrollment to their eligible patients as an act of therapeutic beneficence.

Molecular pathology of tumor metastasis III. Target array and combinatorial therapies

Therapy of tumor progression and the metastatic disease is the biggest challenge of clinical oncology. Discovery of the diverse molecular pathways behind this complex disease outlined an approach to better treatment strategies. The development of combined cytotoxic treatment protocols has produced promising results but no breakthrough in the clinical management of metastatic disease. The multiple - specific and non-specific pathways and cellular targets of tumor progression are outlined in this review. Such an approach, individually designed for various cancer types, may have a better chance to treat or even cure cancer patients with progressive disease.