The possible causes of foot pain caused by stomach cancer are as follows: 1. Bone metastasis, although bone metastasis rarely occurs in stomach cancer, and metastasis to the feet is even more rare, but stomach cancer may metastasize to any part of the body at an advanced stage, and when it metastasizes to the metatarsal and ankle bones of the feet, it will cause foot pain. 2. Lower limb edema, patients with stomach cancer often cannot eat or eat very little, and their nutritional status is mostly poor, and the concentration of albumin in the blood is very low, resulting in obvious edema in the lower limbs. The edema of the skin of the dorsal foot and anterior tibial area can cause pain and paralysis. 3. Thrombosis, the blood of patients with malignant tumors such as gastric cancer is generally in a hypercoagulable state, that is, the blood can be easily coagulated, and coupled with the fact that patients with gastric cancer have little activity and are bedridden for a long time, thrombosis of veins or arteries can be easily formed. Venous thrombosis can lead to obstruction of venous reflux, skin swelling and pain in lower limbs, while arterial thrombosis can lead to ischemic necrosis and sudden severe pain in lower limbs.4. Other causes, such as abdominal implantation metastasis of gastric cancer, abdominal mass can compress sciatic nerve and other lower limb nervous system, which can lead to pain in lower limbs and feet.