High Blood Sugar in Pancreatic Cancer: Should You Be Concerned?

High blood sugar (hyperglycemia) is common in people with pancreatic cancer and usually deserves attention, but not panic. It can occur because the pancreas helps control insulin and blood sugar, and cancer-related changes can disrupt this balance. ^[1] In many cases, new or worsening diabetes around the time of a pancreatic cancer diagnosis is recognized, especially in adults over 50. ^[2] Keeping blood sugar in a reasonable range can support treatment tolerance and reduce complications, so it’s something to monitor and manage with your care team. ^[3]

Why High Blood Sugar Happens

• Pancreas and insulin: The pancreas makes insulin, the hormone that lowers blood sugar; when the pancreas is affected by cancer, insulin regulation can be altered. ^[1] This disruption can lead to high blood sugar or new-onset diabetes in people without a prior history. ^[2]
• Tumor-related signals: There is evidence that pancreatic tumors can send signals that reduce insulin production or action, contributing to hyperglycemia. ^[4] This means high blood sugar may occur even when the tumor hasn’t destroyed most of the pancreas. ^{[5] [6]}

How Common Is It?

• Hyperglycemia and diabetes are relatively frequent in pancreatic cancer. ^[5] New-onset diabetes within about two years before diagnosis is noted in some people, and in a subset, blood sugar improves after tumor treatment. ^{[7] [6]}

Why It Matters

• Treatment tolerance and infection risk: Managing blood sugar can help reduce risks like infections and support better tolerance of therapies such as chemotherapy or steroids that can push sugars higher. ^[3] Good glucose control is generally part of supportive cancer care to help you stay on track with treatment. ^[3]
• Surgery implications: When large portions or all of the pancreas are removed, diabetes can result and will require insulin and education on monitoring. ^[8] Care teams plan proactively for blood sugar management around pancreatic surgery. ^[8]

When to Be Concerned

• Persistent high readings: Repeated fasting blood sugars above target or frequent post-meal spikes should prompt discussion with your oncology and primary care teams. ^[3] Symptoms like excessive thirst, frequent urination, blurry vision, or unintended weight loss can signal higher-than-desired glucose levels. ^[3]
• New-onset diabetes after age 50: Sudden diabetes in this age group especially without family history can be associated with pancreatic disease and generally warrants appropriate evaluation, which your clinicians will coordinate. ^[2] That said, many people with long-standing type 2 diabetes also have elevated risk, so individual context matters. ^[1]

How It’s Managed

• Monitoring: Your team may recommend regular fingerstick checks or a continuous glucose monitor to track patterns during treatment. ^[9] Tracking helps tailor medications and nutrition around chemo, steroids, or surgery. ^[3]
• Medications: A range of drugs can be used; for some, sulfonylureas like glipizide are studied and used to stimulate insulin release when appropriate. ^[10] Your clinicians choose therapy based on your cancer plan, kidney function, appetite, and risk of low blood sugar. ^[3]
• Nutrition strategies: Small, frequent balanced meals can reduce large swings in glucose and support energy needs during treatment. ^[11] Dietitians in cancer centers help align nutrition with both diabetes control and cancer therapy. ^[3]

Practical Tips You Can Use

• Share glucose logs: Bring your readings to oncology visits so adjustments can be made in real time. ^[3] Ask about timing checks on chemo or steroid days, when sugars may trend higher. ^[3]
• Coordinate care: Clear communication between oncology and primary care/endocrinology is helpful; many people benefit from a named clinician overseeing diabetes during cancer care. ^[12] Care plans often set individualized glucose and A1C targets to balance safety and quality of life. ^[13]

Key Takeaways

• High blood sugar is common in pancreatic cancer and usually manageable with monitoring, medication adjustments, and nutrition support. ^{[1] [3]}
• New or worsening diabetes around diagnosis can occur due to tumor-related effects on insulin pathways, and sometimes improves after treatment. ^{[4] [7]}
• Early and ongoing management can reduce complications and help you stay on schedule with cancer therapy. ^[3]

If you’re noticing rising sugars or symptoms, bringing this up promptly allows your team to fine-tune your plan and keep you safer throughout treatment. ^[3]