Following the publication of several studies discussing the occurrence of transfusional iron overload in cancer survivors, Resonance Health asked specialist healthcare providers to complete a survey on clinical practice in monitoring and treating iron overload in this cohort. The survey response was excellent and as such is considered a valid snapshot of current practice.
Iron overload is increasingly recognised as a possible complication in cancer survivors who received multiple blood transfusions as part of their cancer therapy. Iron overload can result from treatments for both blood and solid tumours and can persist for years after cancer treatment. Excess iron is deposited in tissues of the body, potentially causing tissue damage and organ failure. The duration of exposure to high iron burden is directly related to adverse outcomes. As such, a reliable, non-invasive, and accurate measure of body iron stores is required to manage the treatment of iron-related toxicity.
Dr Angela Smith, Assistant Professor, Division of Pediatric Blood and Marrow Transplantation at the University of Minnesota, commented on the importance of monitoring and managing iron overload in cancer survivors:
“Cancer survivors with excess iron may be exposed to this iron for years ahead if untreated, so timely monitoring and reduction of iron burden is an important goal. In our recent data we found even at relatively low thresholds of serum ferritin, liver iron concentration can be elevated in these patients. Conversely, a high serum ferritin, which may be caused by inflammation or other factors, may not be reflective of high liver iron concentration.
FerriScan provides us with a standardized and reliable tool to screen cancer survivors and guide treatment where required. FerriScan is especially suitable for pediatrics as it is free-breathing and quick. It is also unaffected by the presence of fat in the liver, which can be an issue in cancer survivors as a result of their therapy. We recommend that all patients who have undergone hematopoietic stem cell transplantation (HSCT) or those who have received > 10 transfusions should be considered for assessment using FerriScan.”
With the effects of iron overload in haemoglobinopathies such as Thalassemia and Sickle Cell Disease well documented, concerns are now being raised about the incidence of transfusional iron overload in cancer survivors. Currently monitoring for iron overload is mentioned in some cancer survivorship guidelines but is noticeably absent from others. The results contained in this report were collated from 33 respondents across 11 centres of excellence, treating a substantial number of patients between them. The respondents were from the UK, US, and Germany, including Clinicians, Specialist Nurses, and other healthcare providers. This report presents the findings from these experts in the treatment of cancer on current clinical practice and reveals the variations in current screening and treatment practice and highlights the need for improved iron monitoring.
Over 90% of respondents were clinicians, 6% were specialist nurses, and 3% fell into the ‘Other’ category. Respondents were asked a variety of questions about current clinical practices in screening for and treatment of iron overload in their cancer survivor patients.
Summary of Results
How many patients received transfusions or iron supplements as part of their cancer therapy?
Over 42% had 20 or more patients each year receiving transfusions or supplementary iron as part of their cancer therapy.
What percentage of cancer survivors have received more than 10 transfusions and maybe at risk of transfusional iron overload?
27% of respondents estimated that 10-20% of their patients had received more than 10 transfusions as part of their treatment.
24% estimated that this percentage was 20-40% of their patients.
24% of respondents estimated that 40-60% of their patients had received more than 10 transfusions as part of their treatment.
As a weighted average, this amounts to approximately 24% of patients who receive more than 10 transfusions.
Which disease cohort requires the most transfusions thereby putting them at most risk of transfusional iron overload?
Results indicated that transfusion was used across multiple disease cohorts, however those patients undergoing hematopoietic stem cell transplantation (HSCT) required the most transfusions, followed by the acute myeloid leukemia (AML) patient group then the myelodysplastic syndrome (MDS) group.
How are iron levels in cancer survivors being monitored?
Techniques for monitoring of iron levels varied between respondents. Whilst recent opinion cautions against reliance on serum ferritin as an accurate indicator of body iron stores, over 70% of clinicians used regular blood tests (serum ferritin) as an indicator of iron overload. The majority (65%) use a cutoff level of >1000ng/mL at which further action is required. Interestingly 12.5% used >1500ng/mL and a further 12.5% used >500ng/mL, so there is widespread variability amongst caregivers as to the most appropriate cutoff level. Nearly 40% of respondents use FerriScan to measure liver iron concentration in cancer survivors at risk.
Barriers to optimal iron monitoring in cancer survivors using FerriScan?
69% of respondents stated the lack of guidelines on the use of quantitative MRI measurement of iron overload in cancer survivors was a challenge to the use of FerriScan. The other major barrier to using FerriScan is a lack of funding for performing an MRI for liver iron concentration (19% described this as a minor challenge, 41% described this as a significant challenge). Interestingly, 44% of respondents thought that the perception that other tests, such as serum ferritin and liver biopsy, were more suitable was not a barrier to using FerriScan.
Could iron monitoring be improved at centres treating cancer survivors?
93% of respondents thought that iron monitoring practices could be improved at their centre.
Treatment methods for patients in whom iron overload is detected
Results showed treatment of patients identified with iron overload was widely varied, as the following column graph details. This variability exists both between healthcare providers and within healthcare providers’ patient groups.
Call for information and further local screening using FerriScan for cancer survivors
62% of respondents expressed interest to participate in an iron monitoring audit using FerriScan. 40% desired collaboration with other FerriScan centres to improve iron monitoring and establish guidelines, and over 50% requested further information.
- The clinical survey showed that a significant percentage of cancer survivors treated by these respondents were exposed to transfusional iron overload. Almost half of respondents said at least 20% of their cancer survivors had received over 10 transfusions.
- There is a widespread call amongst these clinicians for more information and guidance on iron monitoring and management in cancer survivors. This is supported by participants’ perception that lack of guidelines alongside funding is a current challenge to optimal iron monitoring in this cohort.
- An overwhelming 93% of survey participants indicated that iron monitoring could be improved at their centre and the majority indicated they would like to participate in a local screening program using FerriScan to better identify and treat patients at risk. There is a strong desire for collaborations between centres on this. As FerriScan is the Gold Standard measurement for Liver Iron Concentration, regulatory cleared, and standardised, there may be immediate opportunities for a FerriScan information network to advance health outcomes in this area.
- Resonance Health will continue to engage and partner with the clinical community to add value to local screening programs. Wherever possible we will promote the use and benefits of FerriScan and facilitate collaborations between centres to assist in the management of potential iron toxicity and late effects in this vulnerable patient cohort. As serum ferritin is an acute phase reactant, using it as a measure of liver iron concentration may not be as accurate as required and recent opinion cautions against reliance on it.
Thank you very much to all those that participated in the survey.