The prevalence of pancreatic cysts has increased substantially over the last few decades (Farrell, 2015), mainly because of the increasing use and quality of cross-sectional imaging in modern medical practice (Fung et al, 2022). Three types of cystic lesions are observed in the pancreas—retention cysts, pseudocysts and cystic neoplasms (Karoumpalis and Christodoulou, 2016.). Retention cysts are simple cysts with no clinical significance (Kim and Cho, 2015). Pseudocysts are often a sequelae of acute pancreatitis with significant inflammation, and their management is guided by symptoms. A simple follow up is often appropriate in asymptomatic cases, whereas drainage or resection is required for symptomatic pseudocysts (Misra and Sood, 2023).
Cystic neoplasms can be further subdivided into mucinous or non-mucinous, with the former possessing a certain malignant potential (Scholten et al, 2018). Intraductal papillary mucinous neoplasms (IPMNs), a type of mucinous cystic neoplasm, are the most commonly encountered pancreatic cysts (Muniraj and Aslanian, 2018). There are three subtypes of IPMN: side-branch, main duct and mixed (harbouring features of both side-branch and main-duct IPMN) (Ohtsuka et al, 2024). Side-branch are the most frequently observed IPMNs and have a relatively lower malignant potential compared to their main-duct and mixed counterparts (Hackert et al, 2015).
Given their malignant potential, IPMNs raise understandable concern for patients and clinicians alike. The challenge in practice is identifying the high-risk and potentially premalignant pancreatic lesions amongst the huge number of incidentally detected cysts. When an IPMN is within the radiological differential, appropriate surveillance must be considered. The purpose of a cyst surveillance protocol is to enable early identification of ‘worrying features’ or ‘high-risk stigmata’ that would prompt a surgical consideration. Therefore, cyst surveillance is clearly not appropriate for patients who would be unsuitable for major pancreatic surgery. Sahora et al (2015) suggests that for patients with multimorbidity, objectively defined as a Charlson Comorbidity Score (Charlson et al, 1987) of seven or above, surveillance is not appropriate. Similarly, the American College of Radiology guidelines (Megibow et al, 2017) suggest no surveillance for patients aged over 80 years.
Where PC surveillance is appropriate, the clinician must consider a protocol that enables early identification of high-risk cases, while considering both patient burden and the healthcare economic landscape. Resource use and patient burden are important considerations, particularly since up to 80% of IPMNs have a relatively low malignant potential (Ohtsuka et al, 2024).
The management and surveillance of pancreatic cysts is variable. The cause of this inconsistency is likely multifactorial, due in part to their incidental diagnosis by clinicians outside of a gastroenterology or pancreatology specialty and the absence of dedicated surveillance infrastructures (Hernandez-Barco et al, 2024). In most NHS hospitals, patients who require PC surveillance are often referred to the local gastroenterology, upper gastrointestinal or hepato-pancreato-biliary (HPB) service. Few centres have a dedicated pancreatic cyst surveillance clinic, with the exception being the west of Scotland, where there is a thriving PC surveillance service that currently monitors over 1300 patients (McGuigan et al, 2023). Internationally, dedicated PC services have been most readily adopted in the US, with some programmes delivered by nurse practitioners (Memorial Sloan Kettering Cancer Center, 2024).
Pancreatic cyst surveillance is an important part of the wider pancreatic cancer early detection effort and should be approached in a comprehensive, guideline-driven and patient-focused manner. Arguably, robust follow-up of these lesions requires dedicated and centralised surveillance services. Based on similar models both domestically and internationally, the gastroenterology advanced clinical practitioner (ACP) is well-positioned to design and develop such a service.
Aims
The aim was to establish an ACP-led pancreatic cyst surveillance service within a large tertiary teaching hospital. The primary goal of this service was to ensure the delivery of a standardised and evidence-based approach to pancreatic cyst management. In centralising and standardising the approach to pancreatic cyst surveillance, the team intended to improve the experience, retention and follow up of patients diagnosed with pancreatic cysts. Robust surveillance of patients with pancreatic cysts may improve early detection of pancreatic cancer by enabling prompt identification of operable cases (Ohtsuka et al, 2024).
Methods
A pancreatic cyst surveillance clinic was established in April 2023 and continues to operate. Surveillance was delivered in line with the international guidelines (Ohtsuka et al, 2024) and regional HPB multidisciplinary teams' recommendations.
Inclusion and exclusion criteria
Any patient identified as having a pancreatic cyst on cross-sectional imaging could be referred to the clinic. Referrals were triaged primarily by the ACP. Patients with a benign appearing cystic lesion on imaging were invited to enrol in surveillance, provided they were fit enough to withstand pancreatic resection. The Charlson comorbidity score (Charlson et al, 1987) and Eastern Cooperative Oncology Group (Oken et al, 1982) performance scores aided with decision making regarding surgical fitness. However, it was acknowledged that these decisions often involved considerable nuance and were seldom unambiguous. In such cases, the expertise of the local HPB physicians and regional multidisciplinary team was sought. Patients with a malignant-appearing lesion, those clearly unfit for surgical resection, or those who declined further intervention were excluded and managed appropriately by their primary clinical team.
Surveillance protocol
Although there are several other protocols, the team's surveillance was aligned with the current international guidelines (Ohtsuka et al, 2024) – a decision reached in conjunction with the regional HPB service. Cysts displaying high-risk stigmata (causing obstructive jaundice, an enhancing mural nodule, significant pancreatic duct dilatation or displaying suspicious cytology) were referred directly to the HPB multidisciplinary team for surgical consideration.
Patients with cysts demonstrating associated worrying features were referred to the HPB multidisciplinary team for decision-making regarding the appropriate next steps. Worrying features included:
In some cases, the multidisciplinary team (MDT) would recommend endoscopic ultrasound (EUS) with fine needle aspiration of the cystic lesion. Despite the high accuracy of this diagnostic test (Rogowska et al, 2023), EUS is not included in the international surveillance protocol.
Ohtsuka et al (2024) argued that this is because access to high-level EUS and cytological sampling is not internationally ubiquitous and the guidelines serve to be widely implementable across the global landscape. However, the guidelines do include ‘suspicious or positive cytology’ as a high-risk stigmata, recognising the ability of some centres to perform EUS guided fine needle aspiration.
For all other cystic lesions, surveillance involved interval magnetic resonance imaging (MRI) scans of the pancreas. In cases where MRI was contraindicated, a computed tomography of the pancreas or endoscopic ultrasound was the diagnostic of choice. Surveillance intervals were determined by the size of the cyst. For those under 2 cm, a scan would be arranged after 6 months and every 18 months afterwards. Patients with PC ≥2 cm and <3 cm would receive a similar 6-month index scan, with 12-monthly surveillance afterwards.
For patients with cysts above 3 cm, the guidelines suggest 6-monthly interval scans, however these patients were first referred for MDT discussion. Surveillance diagnostics were arranged by the ACP and patients updated about their results and next steps during a telephone or face-to-face consultation.
Data collection
A robust database was designed to capture details relevant to pancreatic cysts, their surveillance and progression. It was intended that synchronous data collection would serve to generate a comprehensive repository of information relating to pancreatic cysts—aiding future research into this evolving field and steering future guideline development. Data were collected via a trust-approved spreadsheet programme. The database was password protected and accessible only to those directly involved with the service.
Outcomes
Over a 12-month period (April 2023–April 2024), the surveillance clinic received 144 referrals. Of these, 134 are undergoing active surveillance. Surveillance was deemed unnecessary for six patients who were non-surgical candidates. Two patients were diagnosed with inflammatory cysts, eliminating the need for surveillance because of the absence of malignant potential. One patient relocated and transferred their surveillance to another trust, while another declined active surveillance.
Of the 134 patients under active surveillance, 95 (70.9%) were diagnosed with side-branch IPMNs. These are the most commonly encountered mucinous neoplasms and carry the lowest malignant potential (Hackert et al, 2015). A total of 11 patients (8.2%) had suspected main duct IPMNs. While these are encountered less frequently than their side branch counterparts, they pose a higher risk of harbouring invasive malignancy (Fuente et al, 2023).
One patient (0.7%) had a mixed IPMN, which possessed the characteristics of both a side-branch and main duct IPMN. A total of 25 patients (18.7%) had unclassified or indeterminate cysts, highlighting the limitations of radiological studies in differentiating pancreatic cysts. Finally, two patients (1.5%) had suspected serous cystadenomas, which were non-cancerous and typically only resected if symptomatic. So far, malignant transformation has not been observed in these patients.
However, 18 patients had cysts displaying worrisome features and three had associated high-risk stigmata factors predictive of lesions harbouring high-grade dysplasia or invasive carcinoma (Ohtsuka et al, 2024). These patients are undergoing more intensive surveillance or are awaiting discussion in the regional HPB MDT. This data is presented in Table 1.
| Referrals received | 144 |
|---|---|
| Cases under active surveillance | 134 |
| Side-branch IPMN | 95 |
| Main duct IPMN | 11 |
| Mixed IPMN | 1 |
| Serous cystadenoma | 2 |
| Indeterminate cysts | 25 |
| Associated worrying features | 18 |
| Associated high-risk stigmata | 3 |
IPMN: Intraductal papillary mucinous neoplasms
Of all surveyed patients, 93% (n=16) reported a greater sense of involvement in their care related to pancreatic cyst surveillance. Additionally, patients reported a better understanding of their pancreatic cyst and their individual surveillance protocol (93%). Multiple specialties, including primary care, referred patients to the surveillance clinic. Referrer feedback (n=77) was overwhelmingly positive and staff were satisfied with this innovative service (100%).
Discussion
Within the service, side-branch IPMNs are the most frequently diagnosed pancreatic cysts (70.9%). A modest number of cases display ‘worrisome features’ (13.5%) and very few (2.3%) have associated high-risk stigmata. These results are similar to the long-term outcomes of larger epidemiological studies (Fuente et al, 2023). In contrast to other case series, the development of pancreatic cancer has not been observed within the clinic, however this may represent the relative infancy of this service and the limited time the current patients have been under surveillance.
Evaluation of this service is somewhat limited by the absence of a direct control group. Considering the intended outcomes of this pancreatic cyst surveillance infrastructure (improving patient retainment, follow-up and experience, earlier diagnosis of resectable pancreatic cancer and a reduction in surveillance variation), direct comparison with a control group (those undergoing follow up outside of a dedicated surveillance service) would be highly relevant and may be a future consideration.
Although the development of a dedicated pancreatic cyst surveillance clinic represents a change in practice, the management of these cysts remains driven by international guidelines. As such, the establishment of the service does not represent a significant departure from standard practice and although considered, ethical approval was not formally sought.
Robust surveillance of patients with pancreatic cysts may improve early detection and prognosis of pancreatic cancer by facilitating the timely identification of resectable cases. A centralised service that adopts a single, agreed-upon guideline will reduce variation in the management of these cysts, ensure these complex lesions are under specialist observation and offer a single point of contact, improving patient retention, follow up and experience. Therefore, the establishment of similar pancreatic surveillance clinics should be considered, providing regional access to a dedicated surveillance service. To establish such a model, an innovative gastroenterology service with access to regional HPB expertise, local gastrointestinal radiology support and clinicians willing to lead on service provision and data collection is required.
Conclusions
Service development and delivery is a fundamental aspect of advanced practice, as highlighted throughout the multi-professional framework. The design and delivery of this innovative surveillance service demonstrates the underpinning pillars that are central to advanced clinical practice. Drawing on extended clinical expertise while leveraging a leadership position to work across boundaries and foster effective professional relationships, ACPs can drive service redesign in response to local need. The development of a specialist service encourages ACPs to assess and address their own learning needs, relative to the area of service design and provision, further broadening their clinical acumen within their scope of practice.