New guideline released on diagnosis, management of pancreatic cysts

The American Gastroenterological Association (AGA) released a new guideline last week on the diagnosis and management of asymptomatic neoplastic pancreatic cysts.

Incidental identification of pancreatic cysts is growing due to increased use of more sophisticated imaging techniques, and a reliable strategy is needed to determine which of these cysts are related to cancer or high-grade dysplasia, the guideline said. While the guideline is based on a technical review of the literature, the available evidence on management of pancreatic cysts is very low quality and is mostly from case series. However, the AGA Clinical Practice Guideline Committee stated that it was still important to develop a guideline based on this evidence because the clinical problem is so complex. The committee rated each recommendation as strong, meaning that it should apply to most patients most of the time, or conditional, meaning that the decision is more nuanced and there could be different approaches for a significant number of patients.

Regarding surveillance, the AGA suggested the following conditional recommendations:

• Patients who have pancreatic cysts smaller than 3 cm with no solid component or dilated pancreatic duct should have an MRI in 1 year, then every 2 year for a total of 5 years if the cyst does not change in size or characteristics.
• Pancreatic cysts with 2 or more high-risk features, such as a size of 3 cm or greater, a dilated main pancreatic duct, or an associated solid component should be examined with endoscopic ultrasonography (EUS)-fine-needle aspiration (FNA).
• Patients who have no concerning findings on EUS-FNA should have MRI after 1 year and then every 2 years to make sure that risk of malignancy hasn't changed.
• EUS-FNA should be performed in patients whose cysts develop significant changes, such as development of a solid component, increased size of the pancreatic duct, and/or a diameter of 3 cm or more.
• Continued surveillance is not necessary if the characteristics of the cyst have not changed significantly after 5 years of surveillance or if the patient is no longer a candidate for surgery.

The AGA also suggested surgery in patients whose cysts have a solid component and a dilated pancreatic duct and/or concerning features on EUS-FNA (conditional recommendation) and recommended referral to a center that has demonstrated expertise in pancreatic surgery (strong recommendation).

After surgical resection of a cyst with invasive cancer or dysplasia, the AGA suggests MRI surveillance of the remaining pancreas every 2 years. Patients whose cysts do not show high-grade dysplasia or malignancy at surgical resection do not need routine surveillance, the AGA suggests. Both of these recommendations are conditional.

The complete guideline was published online March 25 by Gastroenterology.

A related commentary published online by Annals of Internal Medicine put the guideline into perspective for physicians in general internal medicine. The commentary author said because the available evidence is limited, the technical review on which the guideline is based cannot definitively answer the questions that would be most helpful to patients and physicians, namely how often an incidental cyst harbors unsuspected cancer or precancer that will probably progress to a life-threatening condition; how well imaging or clinical characteristics help select patients most likely to benefit from surgery; what further diagnostic procedures and tests add; whether surgery at an asymptomatic stage and postsurgical surveillance would reduce mortality from pancreatic cancer; and whether the benefits of surgery would outweigh the harms and costs of work-up and treatment.

The commentary author said that the AGA position offers a middle ground between pursuing an aggressive strategy and deferring action until there is more evidence is available. He noted that the AGA takes into account the concern that aggressive strategies are often of low value and that any benefit may not justify harms and costs, while also recognizing “the problems of complete inaction in this situation.” The commentary author also congratulated the AGA for its “bold recommendations” and noted that recommending less aggressive care is often difficult for any group to do.

“Until better evidence is available, we will not know if the AGA guidelines provide greater value than previous ones, but they thoughtfully adopted a value framework,” he wrote. “To get value from new technology, we have to learn to use it with the restraint necessary to minimize harms and costs while preserving benefit.”