<s>[INST] Hello, my father was diagnosed with pancreatic cancer (tumor in the head) in the beginning of June. 2 weeks after he underwent Whipple procedure. Histology showed T3N1M0 with tumor infiltrated in the duodendum and a couple of regional nodes. He was doing great, with really fast recovery and no post op pains. Till he started chemo with Gemzar. 3 infusions after and he is now with severe abdomen pain radiating to his back (left side). Is it the cacer progressing or it could be a side effect of the chemo? We got used to the fever and the mild edema but the abd pain? He was feeling so well before it. [/INST] Gemcitabine is unlikely to cause abdominal pain but pancreatic cancer recurrence is well know. If the pain is not subsiding with medications including gastric protectants , if all labs including serum amylase is normal, get an imaging done to rule out recurrence. </s>