Preoperative intravenous iron therapy and survival after colorectal cancer surgery: long-term results from the IVICA randomised controlled trial

The impact of iron deficiency on patients under evaluation for colorectal cancer, a prospective cross-sectional study

BACKGROUND AND OBJECTIVE

Iron deficiency affects more than 60% of colorectal cancer patients at the time of diagnosis. Iron deficiency ultimately leads to anemia, but additionally, iron deficiency might impact other domains of colorectal cancer patients' health and well-being. The aim of this study was to evaluate the impact of iron deficiency on fatigue, quality of life, cognition, and physical ability in patients undergoing evaluation for colorectal cancer.

METHODS

Multicenter, prospective, observational cross-sectional study (2021-2023). Fatigue was the primary outcome, measured using the Focused Assessment of Cancer Treatment-Anemia questionnaire (FACT-An). Quality of Life, Cognition, Aerobe capacity, mobility, and peripheral muscle strength were tested as secondary outcomes. Multivariate analysis was performed to estimate the impact of iron deficiency on all outcomes.

RESULTS

Two hundred and one patients were analyzed, 57% being iron deficient. In multivariate regression analysis, iron deficiency was not associated with fatigue: FACT-An (r = -1.17, p = 0.57, 25% CI: -5.27 to 2.92). Results on quality of life, cognition, and mobility were non-significant and with small regression coefficients. Iron deficiency showed a nearly significant association with reduced hand-grip-strength (r = -3.47 kg, p = 0.06, 25%CI -7.03 to 0.08) and reduced 6 min walking distance (r = -40.36 m, p = 0.07, 25%CI: -84.73 to 4.00).

CONCLUSION

Iron deficiency in patients undergoing evaluation for colorectal cancer was not associated with fatigue, quality of life, or cognition, but might affect aerobic endurance and peripheral muscle strength to a degree that is clinically relevant.

Association between preoperative anemia optimization and major complications after non-cardiac surgery: a retrospective analysis

BACKGROUND

Anemia is common in the preoperative setting and associated with increased postoperative complications and mortality. However, it is unclear if preoperative anemia optimization reduces postoperative complications. We aimed to assess the association between preoperative anemia optimization and a composite endpoint of major cardiovascular, renal, and pulmonary complications and all-cause mortality within 30 days after noncardiac surgery in adult patients.

METHODS

In this retrospective analysis preoperative anemia was defined as hemoglobin concentration below 12.0 g.dl-1 in women and 13.0 g.dl-1 in men within 6 months before surgery. A propensity score-based generalized estimating equation analysis was used to determine the association between preoperative anemia optimization and the primary outcome. Moreover, mediation analysis was conducted to investigate whether intraoperative red blood cell transfusion or duration of intraoperative hypotension were mediators of the relation between anemia optimization and the primary outcome.

RESULTS

Fifty-seven hundred anemia optimized, and 8721 non-optimized patients met study criteria. The proportion of patients having any component of the composite of major complications and all-cause mortality was 21.5% in the anemia-optimized versus 18.0% in the non-optimized, with confounder-adjusted odds ratio estimate of 0.99 (95% CI 0.86‒1.15) for anemia optimization versus non-optimization, p = 0.90. Intraoperative red blood cell transfusion had a minor mediation effect on the relationship between preoperative anemia optimization and the primary outcome, whereas duration of intraoperative hypotension was not found to be a mediator.

CONCLUSION

Preoperative anemia optimization did not appear to be associated with a composite outcome of major in-hospital postoperative cardiovascular, renal, and pulmonary complications and all-cause in-hospital mortality.

Preoperative intravenous iron treatment - a cohort study on colorectal cancer recurrence

Background

Intravenous (i.v.) iron treatment has been speculated to increase the malignant potential of colorectal malignancies but also to enhance the immune systems potential to fight the invasive tumor. Clinical data however is very limited. We investigate if preoperative i.v. iron treatment is associated with colorectal cancer (CRC) recurrence.

Methods

Retrospective cohort study on surgical CRC patients with iron deficiency anemia (1st March 2013 - 31st December 2019). Patients were grouped based on whether they had received preoperative treatment with i.v. iron. Local data was combined with data from the National Danish Health registries to identify recurrences, death, and emigration. Survival analysis, including Kaplan-Meyer curves and multivariate competing risk analysis adjusting for sex, age, ASA-group, tumor stage, surgical radicality, and miss match repair status was performed.

Results

Of 1228 patients, 125 were available for analysis. 89 patients had received preoperative i.v. iron and 36 had not. The two groups were comparable on baseline and surgical characteristics. Median follow-up times were 4.74 in iron treated patients and 5 years in patients not receiving iron treatment. Five-year rate of non-recurrence was 85 % (0.74-0.91) in the i.v. iron treated group vs. 82 % (0.64-0.91) in the control group, non-significant difference. Multivariate survival analysis did not find iron treatment to be associated with recurrence rates (Hazard Ratio 0.88 (95 % ci; 0.31-2.51).

Conclusion

No association between preoperative i.v. iron treatment and the five-year cancer recurrence rate in iron deficient anemic CRC patients was found.

Perioperative Tracking of Intravenous Iron in Patients Undergoing On-Pump Cardiac Surgery: A Prospective, Single-Center Pilot Trial

BACKGROUND

Preoperative intravenous iron administration is a frequently used patient blood management procedure. If the timeframe of intravenous iron administration before surgery is short, (1) the concentration of the intravenous iron compound might still be high in patients' plasma when undergoing surgery and (2) this iron in patients' plasma is at risk to be lost due to blood loss. The aim of the current study was, therefore, to track the iron compound ferric carboxymaltose (FCM) before, during, and after cardiac surgery requiring cardiopulmonary bypass, with an emphasis on intraoperative iron losses in shed blood and potential recovery through autologous cell salvage.

METHODS

Concentrations of FCM were analyzed in patients' blood using a hyphenation of liquid chromatography and inductively coupled plasma-mass spectrometry to distinguish between pharmaceutical compound FCM and serum iron. In this prospective, single-center pilot trial, 13 anemic and 10 control patients were included. Anemic patients with hemoglobin levels ≤12/13 g/dL in women and men were treated with 500 milligrams (mg) intravenous FCM 12 to 96 hours before elective on-pump cardiac surgery. Patients' blood samples were collected before surgery and at days 0, 1, 3, and 7 after surgery. One sample each was taken of the cardiopulmonary bypass, the autologous red blood cell concentrate generated by cell salvage, and the cell salvage disposal bag.

RESULTS

Patients who had received FCM <48 hours before surgery had higher FCM serum levels (median [Q1-Q3], 52.9 [13.0-91.6]) compared to ≥48 hours (2.1 [0.7-5.1] µg/mL, P = .008). Of 500-mg FCM administered <48 hours, 327.37 (257.96-402.48) mg were incorporated compared to administration ≥48 hours with 493.60 (487.78-496.70) mg. After surgery, patients' plasma FCM concentration in the FCM <48 hours group was decreased (-27.1 [-30 to -5.9] µg/mL). Little FCM was found in the cell salvage disposal bag (<48 hours, 4.2 [3.0-25.8] µg/mL, equivalent to 29.0 [19.0-40.7] mg total; equivalent to 5.8% or 1/17th of the 500 mg FCM initially administered), almost none in the autologous red blood cell concentrate (<48 hours, 0.1 [0.0-0.43] µg/mL).

CONCLUSIONS

The data generate the hypotheses that nearly all FCM is incorporated into iron stores with administration ≥48 hours before surgery. When FCM is given <48 hours of surgery, the majority is incorporated into iron stores by the time of surgery, although a small amount may be lost during surgical bleeding with limited recovery by cell salvage.

Adverse events of iron and/or erythropoiesis-stimulating agent therapy in preoperatively anemic elective surgery patients: a systematic review

BACKGROUND

Iron supplementation and erythropoiesis-stimulating agent (ESA) administration represent the hallmark therapies in preoperative anemia treatment, as reflected in a set of evidence-based treatment recommendations made during the 2018 International Consensus Conference on Patient Blood Management. However, little is known about the safety of these therapies. This systematic review investigated the occurrence of adverse events (AEs) during or after treatment with iron and/or ESAs.

METHODS

Five databases (The Cochrane Library, MEDLINE, Embase, Transfusion Evidence Library, Web of Science) and two trial registries (ClinicalTrials.gov, WHO ICTRP) were searched until 23 May 2022. Randomized controlled trials (RCTs), cohort, and case-control studies investigating any AE during or after iron and/or ESA administration in adult elective surgery patients with preoperative anemia were eligible for inclusion and judged using the Cochrane Risk of Bias tools. The GRADE approach was used to assess the overall certainty of evidence.

RESULTS

Data from 26 RCTs and 16 cohort studies involving a total of 6062 patients were extracted, on 6 treatment comparisons: (1) intravenous (IV) versus oral iron, (2) IV iron versus usual care/no iron, (3) IV ferric carboxymaltose versus IV iron sucrose, (4) ESA+iron versus control (placebo and/or iron, no treatment), (5) ESA+IV iron versus ESA+oral iron, and (6) ESA+IV iron versus ESA+IV iron (different ESA dosing regimens). Most AE data concerned mortality/survival (n=24 studies), thromboembolic (n=22), infectious (n=20), cardiovascular (n=19) and gastrointestinal (n=14) AEs. Very low certainty evidence was assigned to all but one outcome category. This uncertainty results from both the low quantity and quality of AE data due to the high risk of bias caused by limitations in the study design, data collection, and reporting.

CONCLUSIONS

It remains unclear if ESA and/or iron therapy is associated with AEs in preoperatively anemic elective surgery patients. Future trial investigators should pay more attention to the systematic collection, measurement, documentation, and reporting of AE data.

Pre-operative iron increases haemoglobin concentration before abdominal surgery: a systematic review and meta-analysis of randomized controlled trials

Professional surgical societies recommend the identification and treatment of pre-operative anaemia in patients scheduled for abdominal surgery. Our aim was to determine if pre-operative iron allows correction of haemoglobin concentration and decreased incidence of peri-operative blood transfusion in patients undergoing major abdominal surgery. MEDLINE, Embase and CENTRAL were searched for RCTs written in English and assessing the effect of pre-operative iron on the incidence of peri-operative allogeneic blood transfusion in patients undergoing major abdominal surgery. Pooled relative risk (RR), risk difference (RD) and mean difference (MD) were obtained using models with random effects. Heterogeneity was assessed using the Q-test and quantified using the I² value. Four RCTs were retained for analysis out of 285 eligible articles. MD in haemoglobin concentration between patients with pre-operative iron and patients without pre-operative iron was of 0.81 g/dl (3 RCTs, 95% CI 0.30 to 1.33, I²: 60%, p = 0.002). Pre-operative iron did not lead to reduction in the incidence of peri-operative blood transfusion in terms of RD (4 RCTs, RD: − 0.13, 95% CI − 0.27 to 0.01, I²: 65%, p = 0.07) or RR (4 RCTs, RR: 0.57, 95% CI 0.30 to 1.09, I²: 64%, p = 0.09). To conclude, pre-operative iron significantly increases haemoglobin concentration by 0.81 g/dl before abdominal surgery but does not reduce the need for peri-operative blood transfusion. Important heterogeneity exists between existing RCTs in terms of populations and interventions. Future trials should target patients suffering from iron-deficiency anaemia and assess the effect of intervention on anaemia-related complications.

Efficacy of Different Interventions to Reduce Pre- or Perioperative Blood Transfusion Rate in Patients with Colorectal Cancer: A Network Meta-Analysis of Randomized Controlled Trials

Background: The high proportion of blood transfusions before and during surgery carries unnecessary risk and results in poor prognosis in colorectal cancer patients. Different pharmacological interventions (i.e., iron supplement or recombinant erythropoietin) to reduce blood transfusion rates have shown inconclusive results. Methods: This network meta-analysis (NMA) consisted of randomized controlled trials (RCTs) comparing the efficacy of different pharmacologic interventions (i.e., iron supplementation or recombinant erythropoietin) to reduce the blood transfusion rate. NMA statistics were conducted using the frequentist model. Results: Seven RCTs (688 participants) were included in this study. The NMA demonstrated that the combination of high-dose recombinant human erythropoietin and oral iron supplements was associated with the least probability of receiving a blood transfusion [odds ratio = 0.24, 95% confidence intervals (95% CIs): 0.08 to 0.73] and best reduced the amount of blood transfused if blood transfusion was necessary (mean difference = −2.62 U, 95% CI: −3.55 to −1.70 U) when compared to the placebo/control group. None of the investigated interventions were associated with any significantly different dropout rate compared to the placebo/control group. Conclusions: The combination of high-dose recombinant human erythropoietin and oral iron supplements might be considered as a choice for reducing the rate of blood transfusion in patients with colorectal cancer. However, future large-scale RCT with long-term follow-up should be warranted to approve the long-term safety.

Impact of anaemia in oesophago-gastric cancer patients undergoing curative treatment by means of neoadjuvant chemotherapy and surgery

BACKGROUND

The present study investigated factors associated with pre-neoadjuvant chemotherapy (NAC), and pre-operative anaemia, and examined their impact on outcomes in patients with oesophago-gastric cancer treated with curative intent.

METHODS

Patients diagnosed with oesophago-gastric cancer (January 2010 to December 2015) and treated with curative intent by NAC then surgery at a tertiary centre were included. Patients were grouped by the presence of anaemia (haemoglobin <130 mg/L in males and <120 mg/L in females) and into microcytic (MCV <80 fL), normocytic (80-100 fL) and macrocytic (>100 fL) subgroups. Categorical data were analysed by chi-squared test and overall survival by univariate and multivariate Cox regression.

RESULTS

99/295 (34%) patients who received NAC were diagnosed with pre-NAC anaemia, and 157/268 (59%) of patients who subsequently underwent surgery were diagnosed with pre-operative anaemia. Normocytic anaemia was the most common, with 76 (26%) in pre-NAC and 107 (40%) in pre-operative groups. Pre-NAC anaemia was associated with increasing clinical N stage (p = 0.022), higher modified Glasgow Prognostic Score (mGPS) (p = 0.006), and a higher rate of intra-operative transfusion (p = 0.030). Pre-operative anaemia was associated with pre-NAC anaemia (p = 0.004), increasing age (p = 0.026), higher pre-operative mGPS (p = 0.021), and a higher rate of intra-operative transfusion (p = 0.021). Anaemia before NAC and surgery was associated with poorer overall survival in patient following R0 resection, independent of stage (HR 1.26, 95% CI 1.02-1.54, p = 0.030).

CONCLUSION

Anaemia was associated with poorer overall survival and greater requirement for intra-operative blood transfusion in oesophago-gastric cancer patients undergoing treatment with curative intent.

Impact and outcomes of postoperative anaemia in colorectal cancer patients: a systematic review

AIM

Preoperative anaemia is common in colorectal cancer patients. Little attention has been given to the prevalence and consequences of postoperative anaemia. The aim of this study was to systematically review the published literature and determine the knowledge of the prevalence and impact of postoperative anaemia in colorectal cancer patients.

METHODS

The databases Cumulative Index of Nursing and Allied Health Literature (CINAHL) and Medline, via EBSCOhost, were systematically searched to identify suitable articles published between 2004 and 2020. After an initial search, articles were screened and all eligible articles reporting on the prevalence of postoperative anaemia and clinical and long-term outcome data in colorectal cancer patients undergoing surgery were included. The Risk of Bias 2.0 tool for the assessment of randomized controlled trials and the Risk of Bias 1.0 tool for non-randomized studies were used for the assessment of bias in the studies selected in our review.

RESULTS

Six studies, one randomized control trial and five cohort studies, were included with a total population size of 1714. The prevalence of anaemia at discharge of 76.6% was reported as the primary end-point in only one study. The rate of red blood cell transfusion and length of hospital stay were found to be significantly increased in anaemic patients, while postoperative infection rate results were variable. Quality of life scores and overall survival at 5 years were significantly affected among anaemic patients as reported in two papers.

CONCLUSION

The available limited evidence on postoperative anaemia indicates its high prevalence with negative impact on clinical and long-term outcomes. Further research is required to standardize the measurement and address the true impact of correcting postoperative anaemia on functional and oncological outcomes.

Flipside of the Coin: Iron Deficiency and Colorectal Cancer

Iron deficiency, with or without anemia, is the most frequent hematological manifestation in individuals with cancer, and is especially common in patients with colorectal cancer. Iron is a vital micronutrient that plays an essential role in many biological functions, in the context of which it has been found to be intimately linked to cancer biology. To date, however, whereas a large number of studies have comprehensively investigated and reviewed the effects of excess iron on cancer initiation and progression, potential interrelations of iron deficiency with cancer have been largely neglected and are not well-defined. Emerging evidence indicates that reduced iron intake and low systemic iron levels are associated with the pathogenesis of colorectal cancer, suggesting that optimal iron intake must be carefully balanced to avoid both iron deficiency and iron excess. Since iron is vital in the maintenance of immunological functions, insufficient iron availability may enhance oncogenicity by impairing immunosurveillance for neoplastic changes and potentially altering the tumor immune microenvironment. Data from clinical studies support these concepts, showing that iron deficiency is associated with inferior outcomes and reduced response to therapy in patients with colorectal cancer. Here, we elucidate cancer-related effects of iron deficiency, examine preclinical and clinical evidence of its role in tumorigenesis, cancer progression and treatment response. and highlight the importance of adequate iron supplementation to limit these outcomes.