Treating iron deficiency in tumor disease

Tumor diseases and intensive chemotherapy deplete the body's iron reserves. Iron deficiency and anemia can impair prognoses. A rapid diagnosis and iron deficiency therapy is therefore indicated.

Higher risks may occur when doses are reduced in iron deficiency

Tumor diseases and intensive chemotherapy deplete the body's iron reserves. Iron deficiency and anemia can impair prognoses. A rapid diagnosis and iron deficiency therapy is therefore indicated.

A single gram of hemoglobin binds 1.34 ml of oxygen. As is well known, iron is the basis of hemoglobin. But the trace element is just as important for myoglobin, the function of the mitochondria, for the immune system, and for a whole range of different enzymes and hormones.

It is therefore not surprising that an iron deficiency can lead to various symptoms, including tiredness, dizziness, exhaustion, headaches, susceptibility to infections, and, of course, anemia. Finally, anemia is usually the stage of iron deficiency that is clinically diagnosed. However, it would be much better, especially for tumor patients, to detect iron deficiency at an earlier stage, e.g. in the stage of iron-deficient erythropoiesis.

Iron deficiency and anemia are common in tumor diseases

Cancer maintains a chronic inflammatory state in which pro-inflammatory cytokines such as IL-6 are released and the liver reacts by producing hepcidin, which slows down the absorption of iron in the intestine and reduces iron mobilization. Finally, there is an iron deficiency due to inflammation, which can lead to anemia, depending on its severity. It is a fact that the higher the degree of the tumor, the greater the risk of anemia for the affected person.

The main triggers of anemia in oncological patients are on the one hand the reduced iron mobilization described above (therapy or tumor-induced anemia) and on the other hand, depleted iron reserves. Together, both causes lead to iron deficiency in the body cells and to corresponding symptoms.

Consequences of iron deficiency in tumor diseases

Anemic patients have a threefold higher risk of dose reductions and interruptions in therapy, so that anti-tumor therapy is limited in its effectiveness for them. This also increases the risk of recurrence and reduces the overall survival rate.

The greater the iron deficiency, the lower the quality of life of people undergoing therapy. On the other hand, studies have shown that a rising hemoglobin value is associated with increasing quality of life - a clear signal for early correction of iron deficiency.

A Hb value between 11 and 13 g/dl is generally considered optimal for achieving a sufficiently good quality of life. Therefore, iron deficiency should be detected and treated in time before the Hb value drops too much.

An important marker for iron saturation is transferrin saturation (TSAT). If this is < 20%, an iron deficiency is to be assumed and iron levels should be addressed. Simply determining the ferritin value is not sufficient in tumor patients, as ferritin is generally elevated in chronic inflammatory reactions, such as those occurring in cancer, and therefore may give false signals. This has now also been recognized by the current S3 guidelines for supportive therapy and recommends "a determination of transferrin saturation (TSAT) before the start of chemotherapy".

Conclusion

Iron deficiency and anemia are frequent concomitant symptoms of tumor diseases. However, early diagnosis and therapy can improve the therapeutic outcome and quality of life for those affected. According to the S3 guideline "Supportive Therapy", transferrin saturation (TSAT) should be determined as a standard before the start of chemotherapy and iron substitution should be started at a TSAT value <20% - particularly in the case of low iron values, preferably I.V.

Source:
Event: “"Eisenmangel bei Tumorpatienten: Frühzeitig behandeln – Anämie und Transfusionen vermeiden" / "Iron deficiency in tumor patients: Treat early - avoid anaemia and transfusions" (Organiser: Vifor Pharma Deutschland GmbH); DKK 2020, Berlin, 21.02.2020