Endoscopic ultrasound trends of solid pancreatic lesions in Gulf Cooperation Council countries

Introduction

Pancreatic ductal adenocarcinoma (PDAC) is increasingly recognized as a major health challenge worldwide. Although its incidence remains lower in Gulf Cooperation Council (GCC) countries compared to Western nations, there has been a rising trend likely influenced by demographic shifts and increasing prevalence of risk factors such as obesity and diabetes (1). A recent analysis of cancer patterns in Saudi Arabia confirmed that although pancreatic cancer remains relatively rare compared to other malignancies, its mortality rate is disproportionately high due to frequent late-stage presentation (2). Similarly, a study examining the cancer burden in the Eastern Mediterranean region, including GCC countries, highlighted that pancreatic cancer had one of the lowest survival rates among gastrointestinal cancers, attributed to diagnostic delays and limited early detection programs (3).

Although national cancer registries, such as the Saudi Cancer Registry, report on pancreatic cancer incidence and mortality, detailed datasets capturing benign pancreatic lesions, cystic neoplasms, and neuroendocrine tumors (NETs) remain scarce (2). Most studies from the GCC countries are retrospective, single-center analyses with relatively small cohorts, limiting their applicability to the broader regional population (4). These findings underscore the need for region-specific strategies focused on early diagnosis, risk factor modification, and the development of specialized pancreatic cancer centers to improve outcomes in the GCC countries.

Thus, this study aimed to address the existing gap in regional data by conducting a comprehensive analysis of solid pancreatic lesions evaluated by endoscopic ultrasound (EUS) in the GCC countries. Specifically, the study sought to characterize demographic profiles, clinical presentations, lesion features, and diagnostic outcomes associated with EUS. We present this article in accordance with the STROBE reporting checklist (available at https://tgh.amegroups.com/article/view/10.21037/tgh-25-64/rc).

Methods

Retrospective, descriptive study aimed to evaluate solid pancreatic lesions identified by EUS across seven healthcare institutions in three GCC countries [Kuwait, Saudi Arabia and United Arab Emirates (UAE)], Participating institutions included Al-Amiri Hospital, Kuwait; Cleveland Clinic Abu Dhabi, Abu Dhabi, UAE; King Abdulaziz University, Jeddah, Saudi Arabia; King Fahad Specialist Hospital, Dammam, Saudi Arabia; Mubarak Al-Kabeer Hospital, Kuwait; National Guard Hospital, King Abdullah Medical City, Jeddah, Saudi Arabia; Rashid Hospital, Dubai, UAE. The study period extended from 2020 to 2024. Data were extracted from hospital medical records, EUS reporting databases, and pathology reports. Variables collected included patient demographics, clinical presentation, imaging findings, EUS sampling methods, and treatment recommendations (surgical resection, chemotherapy, observation, or other interventions).

A total of 551 patients who underwent EUS for the evaluation of solid pancreatic lesions were included. Eligibility criteria encompassed patients undergoing EUS for suspected pancreatic lesions or for other indications where relevant clinical and imaging data were available. Patients whose primary diagnosis was a cystic pancreatic lesion were excluded. EUS procedures were performed by advanced endoscopists using high-frequency linear echoendoscopes. Sedation techniques, including conscious sedation, deep sedation, or general anesthesia, were applied based on patient condition and institutional protocols.

This study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was conducted in accordance with the ethical standards of the Research Ethics Committee at King Abdulaziz University (approval No. 564-23) and United Arab Emirates Department of Health (approval No. DOH/CVDC/2023/1764). All other participating institutions were also informed of and agreed to the study. Patient confidentiality was protected through data anonymization, and no personally identifiable information was used. The requirement for informed consent was waived due to the retrospective nature of the study.

Statistical analysis

Statistical analyses were performed using SPSS software (IBM Corp., Version 27.0, Armonk, NY, USA). Categorical variables are reported as frequencies and percentages. The Shapiro-Wilk test was utilized to assess the distribution pattern of continuous variables. Normally distributed variables are presented as means with standard deviations, while non-normally distributed variables are presented as medians with interquartile ranges. The Chi-squared test was used to assess differences between categorical variables, and the Mann-Whitney U test was used for comparisons involving non-normally distributed continuous variables. A P value of <0.05 was considered statistically significant. Missing data were excluded from the analysis.

Results

A total of 551 patients were recruited for the study, with a mean age of over 61.5±13.7 years. The majority were male (n=330, 59.9%) and less than one third were smokers (n=161, 29.2%). The mean body mass index (BMI) was 26.7±5.6 kg/m². About one third of the participants were Saudi nationals (n=183, 33.2%). This was followed by participants from Kuwait (n=115, 20.9%) and the UAE (n=94, 17.1%). Only one participant (0.2%) was from Bahrain, while no participants were from Oman or Qatar. A significant proportion of the cohort (n=157, 28.5%) were from non-GCC countries. Most patients were symptomatic (n=499, 90.6%). The most common symptom was abdominal pain (n=354, 64.2%) followed by weight loss (n=317, 57.5%) and jaundice (n=256, 46.5%). CT was the most common initial method of diagnosis (n=469, 85.1%) (Table 1). The most commonly used EUS echoendoscope was Olympus [Olympus Medical Systems, Tokyo, Japan (n=348, 63.2%)], followed by Fujifilm [Fujifilm Corporation, Tokyo, Japan (n=143, 26%)] and Pentax [Pentax Medical, Tokyo, Japan (n=60, 10.8%)].

Radiology and EUS findings

On radiologic imaging (Table 2), the most common lesion location was the head/uncinate of the pancreas (n=329, 59.7%), followed by body (n=103, 18.7%), tail (n=35, 6.4%) and neck (n=31, 5.6%). Vascular involvement and lymphadenopathy were observed in 47.2% (n=260) and 42.3% (n=233) of the patients, respectively. Regarding pancreatic duct findings, strictures and irregular contours were relatively uncommon. Features of chronic pancreatitis were observed in 53 (9.3%) patients.

On EUS (Table 3), the most common lesion location was the head/uncinate of the pancreas (n=361, 65.6%), followed by body (n=113, 20.5%), neck (n=37, 6.7%) and tail (n=32, 5.8%). Most lesions were hypoechoic (n=481, 87.3%) and approximately half had poorly defined borders (n=265, 48.1%). Cystic components were observed in 56 (10.2%) patients. At the initial EUS exam, around 226 (41.1%) patients had findings suggestive of vascular involvement. Adverse events were rare (n=9, 1.7%), with the most common event being bleeding (n=7, 1.3%).

Comparison between radiological and EUS findings revealed that the median largest dimension was higher for radiological modalities than EUS [37.0 (25.0–48.0) vs. 34.0 (26.0–42.0) mm, P=0.008] (Table 4). A higher percentage of patients demonstrated vascular involvement on radiological findings than on EUS (n=260 vs. n=226, P<0.001). Finally, a higher percentage of patients were noted to have dilated side branches on EUS compared to radiology (P<0.001).

EUS sampling and diagnosis

Of the 551 patients, 534 lesions (96.9%) were successfully sampled (Table 5). Regarding the sampling method, fine-needle aspiration (FNA) was used in 234 cases (43.8%), fine-needle biopsy (FNB) in 178 cases (33.3%), and a combination of FNA and FNB in 122 cases (22.9%). As for needle size, a 22G needle was the most commonly used (n=437, 81.8%), followed by 25G needles (n=70, 13.1%), 19G needles (n=19, 3.6%), and 20G needles (n=8, 1.5%). The median number of passes per lesion was 3 (interquartile range, 3–4). Rapid on-site evaluation (ROSE) was available in 189 cases (35.4%).

In our cohort, the most common pathologic diagnosis was PDAC, identified in 417 cases (80.1%). NETs were diagnosed in 49 cases (9.4%), and cholangiocarcinoma was found in 3 cases (0.6%) (Table 6). Metastatic lesions accounted for 14 cases (2.7%), originating from breast cancer (n=6, 1.2%), colorectal cancer (n=5, 1%), renal cell carcinoma (RCC) (n=2, 0.4%), and thyroid cancer (n=1, 0.2%). Lymphoma was diagnosed in 13 cases (2.5%). Other diagnoses included solid pseudopapillary tumor (n=3, 0.6%), pancreatic tuberculosis (TB) (n=3, 0.6%), and lipoma (n=2, 0.4%). Autoimmune pancreatitis was observed in 7 cases (1.3%), while normal pancreatic tissue was found in 9 cases (1.7%). Additionally, 31 cases (6.0%) were categorized as non-diagnostic.

Discussion

This study provides insights into the clinical and diagnostic characteristics of solid pancreatic lesions detected on EUS in the GCC countries. In this large cohort of 551 patients with pancreatic lesions, the demographic distribution showed a predominance of older males, aligning with previously established epidemiological trends for pancreatic malignancies, particularly PDAC (5,6). The mean age of 61.5 years and the relatively high male proportion (59.9%) are consistent with global data, where increasing age and male gender are recognized risk factors for pancreatic cancer development (7).

CT was the most frequent initial imaging modality (85.1%), supporting its position as the first-line diagnostic tool for pancreatic lesions due to its high sensitivity and widespread availability (8). Radiologically, the most common lesion location was the pancreatic head/uncinate region (59.7%), corroborating findings from several studies reporting the head of pancreas as the most frequent site of PDAC (9). The EUS findings in our cohort showed a high percentage of hypoechoic lesions (n=481, 87%) with poorly defined borders in nearly half of the cases, consistent with prior reports describing these features as characteristic of malignant pancreatic masses (10). EUS remains a cornerstone for pancreatic lesion characterization due to its superior resolution compared to cross-sectional imaging, particularly for small lesions (<2 cm) (11,12). Interestingly, lesion size was significantly smaller when measured by EUS compared to radiology (P=0.008), which is an observation previously noted by other groups and attributed to EUS’s better spatial resolution (13). Compared to radiological imaging, EUS identified a higher number of cases with dilated side branches (11.6% vs. 4.7%, P<0.001), demonstrating its sensitivity in evaluating ductal abnormalities. This finding is consistent with prior studies, with EUS associated with a higher sensitivity compared to abdominal ultrasound (94% vs. 67%) and computed tomography (98% vs. 74%) in detecting pancreatic lesions (14).

In our cohort, PDAC was the most common diagnosis, accounting for 80.1% of cases. This aligns with global epidemiological data identifying PDAC as the predominant malignant pancreatic lesion (6,15). NETs represented the second most common diagnosis (9.4%), consistent with the increasing recognition and improved detection rates of pancreatic NETs in recent years (16). Metastatic lesions to the pancreas were relatively rare (2.7%), with breast and colorectal primaries being the most frequent, reflecting known metastatic patterns reported in literature (17). Other uncommon diagnoses included lymphoma (2.5%), solid pseudopapillary tumors (0.6%), and pancreatic tuberculosis (0.6%), with the latter being notably rare but important in regions where tuberculosis remains endemic. Autoimmune pancreatitis (1.3%) was also observed, emphasizing the need to distinguish this benign condition from malignancy, given its clinical and imaging overlap (18).

These findings reinforce the growing role of EUS in diagnosing solid pancreatic lesions in the GCC countries. Given its high sensitivity for detecting small lesions, evaluating vascular involvement, and guiding fine-needle sampling, EUS is an essential diagnostic tool that complements radiological imaging. The high prevalence of PDAC among the detected lesions suggests that EUS can facilitate earlier diagnosis and intervention, which is crucial for improving patient outcomes. However, variability in lesion size, cystic components, and symptom presentation suggests that screening and diagnostic protocols may differ across institutions, highlighting the need for standardized guidelines for EUS utilization.

Despite the large size of our cohort, this study has several limitations. Although it was conducted across multiple international centers, the cohort did not include participants from all GCC countries, notably Oman, Bahrain and Qatar, which may limit the generalizability of the findings to the entire GCC region. Differences in healthcare infrastructure, disease prevalence, and referral patterns across countries could have influenced patient characteristics and diagnostic outcomes. Additionally, the retrospective design introduces potential selection bias and incomplete data capture. Operator variability in EUS technique, choice of sampling needles, and inconsistent utilization of ROSE across centers could also have impacted diagnostic accuracy. Another key limitation of this study is the lack of an adequate disease-negative cohort, which prevents meaningful assessment of specificity and overall diagnostic accuracy. In our dataset, true negatives were absent across all categories of needle types and sizes, leaving specificity either undefined or based on extremely small numbers, and thereby unreliable. While sensitivity could be estimated, the small sample sizes for certain needles resulted in very wide confidence intervals, limiting the precision and stability of these estimates. Future prospective studies with standardized diagnostic criteria, improved data collection, and the integration of advanced biomarkers are needed to enhance the reliability and applicability of the findings.

Conclusions

EUS is a critical diagnostic tool for evaluating solid pancreatic lesions in the GCC countries, offering superior lesion characterization, early detection, and reliable tissue sampling. This study highlights the significant role of EUS in the diagnosis of PDAC and other malignancies, supporting its continued integration into clinical practice.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://tgh.amegroups.com/article/view/10.21037/tgh-25-64/rc

Data Sharing Statement: Available at https://tgh.amegroups.com/article/view/10.21037/tgh-25-64/dss

Peer Review File: Available at https://tgh.amegroups.com/article/view/10.21037/tgh-25-64/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://tgh.amegroups.com/article/view/10.21037/tgh-25-64/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. This study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was conducted in accordance with the ethical standards of the Research Ethics Committee at King Abdulaziz University (approval No. 564-23) and United Arab Emirates Department of Health (approval No. DOH/CVDC/2023/1764). All other participating institutions were also informed of and agreed to the study. The requirement for informed consent was waived due to the retrospective nature of the study.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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