ThP4.14 - Updated surveillance guidance for Intra-ductal Pancreatic Mucinous Neoplasm (IPMN) – a 10-year cohort study in a tertiary care Surgical unit Free

To investigate the adequacy of current frequency of surveillance of IPMN in a single tertiary surgical unit

This was a retrospective cohort study over a 10-year period (2013-2023), patient age range 30-85 years old. The data collected included gender, age at diagnosis, size(mm) of largest cyst, high risks(HRF) or worrisome features(WRF) and interventions required.

Analysis undertaken pertaining to the incidence of IPMN with malignant potential as well as progression of disease on surveillance.

• Total of 61 patients.

• On presentation - Cyst size <1cm – 51%, 1-2cm- 33%, 2-3cm- 16%.

• <1cm group - no growth on surveillance scans and no interventions required.

• 1-2cm group - 35% had HRF, 25% of which underwent surgical intervention. 15% showed WF of which 33% required surgical intervention.

• 2-3cm group - 20% of patients with WF showed growth in cyst size. 40% of patients with WF - underwent surgery.

The malignant potential of IPMN correlates with the initial cyst size. Guidelines recommend that cysts <1cm should be under 2-yearly surveillance. However, when compared to those with cyst>1cm, none of the patients with cyst size<1cm displayed progression.

Therefore, we propose that for patients with an initial cyst size of less than 1cm, who are above the age of 70 and/or Performance status (PS) =>2 – no active surveillance is required. If the PS <2 and patients are less than 70 years old, we recommend 5-yearly surveillance. For patients with cyst size >1cm, we recommend adhering to the current guidance. With this revised guidance, already scarce resources may be better utilised.