Understanding Pancreatic Cancer

The pancreas is a 6-inch-long organ of the digestive system, located behind the stomach and in front of the spinal column. It is responsible for producing enzymes that break down food in the intestinal tract and for making hormones that control blood sugar levels.¹ The pancreas has several types of cells that allow it to perform these functions.

As with all cancers, pancreatic cancer occurs when cells grow out of control and avoid the body’s usual growth-control mechanisms. Most types of pancreatic cancer start in the area of the pancreas that produces enzymes or proteins for digestion. More rarely, cells in the area of the pancreas that produces hormones may become cancerous.²

More than 56,000 people are expected to be diagnosed with pancreatic cancer in the United States in 2019.¹ However, the reasons why some people develop pancreatic cancer are not clear. Some patients have mutations or changes to genes that may be involved in cancer development, but for most people, a genetic cause has not been found.^3,4

Some disorders that are inherited or passed down, smoking, carrying excessive body weight, having diabetes or chronic pancreatitis, and exposure to certain chemicals also increase the risk for pancreatic cancer,⁵ but not all patients who get pancreatic cancer have these risks.

There are no recommended tests to screen for pancreatic cancer, and pancreatic cancer cannot be felt during an examination, because the pancreas is located deep within the body.⁶ Once pancreatic cancer starts to develop, it may grow without causing any symptoms until it becomes large or spreads outside the pancreas.⁷ About 80% of people who develop pancreatic cancer are not diagnosed until the cancer is locally advanced or metastatic (spread to other areas of the body).⁸

When pancreatic cancer does cause symptoms, patients most often notice pain in the belly or back, yellowing of the skin or eyes, changes in urine or stool color or consistency, weight loss, loss of appetite, nausea, or vomiting. However, none of these symptoms are specific for pancreatic cancer.⁷ Many other diseases can cause 1 or more of these symptoms.

Once pancreatic cancer has been diagnosed, staging is important to determine which treatment options are available. Two main ways pancreatic cancers are staged are as resectable (removable with surgery) or unresectable (not removable with surgery). Only small tumors that have not spread beyond the pancreas are considered resectable, and a surgeon can attempt to remove the entire cancer if it is found at this early stage.⁹

Unresectable pancreatic cancers include locally advanced cancers and metastatic cancers. Locally advanced pancreatic cancers have grown into or surround nearby body parts (like blood vessels), making surgery potentially dangerous. Metastatic pancreatic cancers have spread to other parts of the body, so surgery on the pancreas cannot remove the cancer completely.⁹

An oncologist (cancer specialist) will consider pancreatic cancer stage, along with several other factors, in determining which treatment options may be appropriate for a patient.

References

1. Pancreatic Cancer Action Network. What is pancreatic cancer? www.pancan.org/facing-pancreatic-cancer/about-pancreatic-cancer/what-is-pancreatic-cancer. 2019. Accessed November 20, 2019.
2. American Cancer Society. What is pancreatic cancer? www.cancer.org/cancer/pancreatic-cancer/about/what-is-pancreatic-cancer.html. Last revised February 11, 2019. Accessed November 20, 2019.
3. Dreyer SB, Chang DK, Bailey P, Biankin AV. Pancreatic cancer genomes: implications for clinical management and therapeutic development. Clin Cancer Res. 2017;23(7):1638-1646.
4. Aguirre AJ, Collisson EA. Advances in the genetics and biology of pancreatic cancer. Cancer J. 2017;23(6):315-320.
5. American Cancer Society. Pancreatic cancer risk factors. www.cancer.org/cancer/pancreatic-cancer/causes-risks-prevention/risk-factors.html. Last revised September 4, 2019. Accessed November 20, 2019.
6. American Cancer Society. Can pancreatic cancer be found early? www.cancer.org/cancer/pancreatic-cancer/detection-diagnosis-staging/detection.html. Last revised February 11, 2019. Accessed November 20, 2019.
7. American Cancer Society. Signs and symptoms of pancreatic cancer. www.cancer.org/cancer/pancreatic-cancer/detection-diagnosis-staging/signs-and-symptoms.html. Last revised February 11, 2019. Accessed November 20, 2019.
8. Herman JM, Kitchen H, Degboe A, et al. Exploring the patient experience of locally advanced or metastatic pancreatic cancer to inform patient-reported outcomes assessment. Qual Life Res. 2019;28(11):2929-2939.
9. American Cancer Society. Pancreatic cancer stages. www.cancer.org/cancer/pancreatic-cancer/detection-diagnosis-staging/staging.html. Last revised December 18, 2017. Accessed November 20, 2019.