Is it unusual for elderly patients to completely lose their appetite after lung cancer surgery?

No: Surgery may temporarily cause anorexia as the body uses all resources to heal. This may cut appetite. The key is to fine foods that the patient really likes. In extreme cases your doctor can prescribe medication to boost appetite. Adequate nutrition is key for complete healing after surgery.

Appetite/Lung Ca: Particularly squamous lung cancer is an appetite thief. Many show up with major weight loss, a sign that points to worse outcome. It is not the treatment, but radiotherapy and chemotherapy can briefly cause diffiuclt swallowing. Successful treatment sometimes brings appetite back. Megace (megestrol) can stimulate appetite for some, but not all.