Thanks for posting your query.
can be an individual entity or can occur secondarily in case of tumors.
In tumors associated with anemia usually Erythropoiten a protein involved in Erythropoiesis
is not produced.
So in such cases Anemia can be tackled by giving Erythropoietin
through external source.
Severity is based on the HB%, Age and the tumor variety.
Hope I have answered your query.
Wishing you good health.