1. Abdominal bloating or pain: Many pancreatic cancer patients initially experience vague upper abdominal pain, along with symptoms such as belching, heartburn, and bloating.

2. Jaundice: Obstructive jaundice, characterized by yellow urine and clay-like stools, is a significant symptom of pancreatic head cancer.

3. Diarrhea: Pancreatic cancer can cause diarrhea due to destruction of pancreatic cells, blockage of ducts, and hormone production. 

4. Abnormal blood sugar changes: Insufficient insulin secretion from pancreatic dysfunction can lead to high blood sugar levels. Sudden uncontrolled high blood sugar may indicate pancreatic problems, especially in diabetic individuals.

5. Chronic pancreatitis: Untreated pancreatic inflammation can progress to chronic pancreatitis, greatly increasing the risk of pancreatic cancer.