hi there, being anemic and low ferritin levels suggests that either the patient is taking less of iron rich food , losing more iron from the body than that which is being replaced like having occult bleeding as may be the case from her GIT or could be due to decreased uptake or absorption of normally ingested iron in food. As your history suggests that she is undergoing upper GI endoscopy
and the doctor suspects malignancy or cancer I would deduct that she is losing blood from her upper gastrointestinal tract which is causing her anemia
and low ferritin levels. Let the biopsy
report come and you will be more in the clear about the cause. In the meanwhile she may require Iron suppliments either oral or in injectable form depending on the severity of her anemia. Take care.