Introduction

Current guidelines advise esophagectomy for submucosal esophageal adenocarcinoma (T1b EAC). However, data from retrospective studies suggest that endoscopic follow-up (FU) may be a valid alternative in patients without signs of lymph node metastases (LNM) at baseline. In this international multicenter, prospective cohort study (NCT03222635), we aim to evaluate the safety of a watchful waiting strategy with regular endoscopic FU in patients treated endoscopically for T1b EAC.

Aims & Methods

This ongoing prospective study is conducted in 19 hospitals in Europe and Australia, and aims to include 141 patients with 5-year FU. After radical endoscopic resection of T1b EAC, patients are re-staged with endoscopic ultrasound (EUS) and CT/PET. In the absence of LNM or distant metastases (N0M0), and upon consent for endoscopic FU, patients are included and undergo strict endoscopic FU with gastroscopy and EUS every 3 months during year 1 and 2, every 6 months during year 3 and 4, and at year 5. CT/PET is repeated after 1 year. We divided our cohort into two groups: ‘high-risk’ (submucosal invasion ≥500um, a/o poorly/undifferentiated tumor (G3-4), a/o lymphovascular invasion (LVI+)) and ‘low-risk’ if no high risk features are present. Primary outcome parameters are 5-year disease specific survival and overall survival; secondary outcome parameters are rate of LNM and local recurrence.

Results

Since July 2017, 134 patients (112 men, median age 69 ±10 years) were included with a median FU of 22 (IQR 11-35) months: 87 high-risk and 47 low-risk patients. 6 patients (4% [95%CI 0.2-8.8]) were diagnosed with LNM (table 1) after median FU of 8 (IQR 5-16) months. Of these 6 patients, 2/6 were referred for neoadjuvant chemo(radio)therapy with esophagectomy (ypT0N1M0, ypT0N0M0), 1/6 underwent esophagectomy only (pT0N2M0), 3/6 underwent a selective surgical resection of the tumor-positive LN.
7 patients (5% [95%CI 0.8-9.6] were diagnosed with an intra-luminal tumor recurrence not eligible for endoscopic re-treatment after median FU of 7 (IQR 6-15) months. 5 had initial ESD and 2 cap-based EMR. Of these 7 patients, 2/7 underwent esophagectomy (pT1bN0M0, pTisN0M0), 1/7 had neoadjuvant chemoradiotherapy and esophagectomy (ypT1aN0M0), 3/7 underwent (chemo)radiotherapy only, of which 1 patient eventually died as result of stenosing EAC, 1/7 refused additional treatment. No distant metastases were diagnosed during FU in both cohorts. Five patients died during FU of a cause unrelated to EAC. Five patients discontinued FU due to old age. Two patients were lost to FU.

N=134	FU (months), Median (IQR)	Lymph node metastasis, N (% [95%CI])	Intra-luminal tumor recurrence*, N (% [95%CI])	Distant metastasis, N (%)	EAC-related death, N (% [95%CI])	Non-EAC related death, N (% [95%CI])
High-risk T1b (N=87)	19 (11-35)	4 (5% [0.1-9.1%])	5 (6% [1.0-10.4%])	0	1 (1% [0-4.0%])	4 (5% [0.1-9.1%])
Low-risk T1b (N=47)	22 (9-36)	2 (4% [0-10.0%])	2 (4% [0-10.0%])	0	0	1 (2% [0-7.3%])

*not eligible for endoscopic therapy

Conclusion

The preliminary analysis from our ongoing prospective study suggest that in patients with radically removed high- or low-risk T1b EAC, without LNM at baseline, a strict endoscopic follow-up protocol is feasible and the window for curative therapy remains open for those patients who develop LNM (4%) or a local intra-luminal recurrence (5%) during FU. Most patients demonstrate uneventful FU.

Disclosure

No conflict of interests.

Introduction

Type 1 AIP is the most common presentation of IgG4-related disease. Serum IgG4 levels are widely used in initial screening and diagnosis, with levels ≥135 mg/dL recommended as part of the diagnostic criteria. However, its diagnostic specificity is limited as it can be elevated in a broad spectrum of neoplastic, infectious, and autoimmune diseases. Histological diagnosis though definitive, remains challenging in real life clinical practice. In recent years, IgG4/IgG ratio has been proposed as a promising alternative serum biomarker.

Aims & Methods

We aimed to study the diagnostic utility of serum IgG4/IgG ratio compared to serum IgG4 alone in the diagnosis of Type 1 AIP. We identified a cohort of patients from 2015 to 2021 who had raised serum IgG4 levels in Tan Tock Seng Hospital, Singapore. Associations between serum IgG4 level and IgG4/IgG ratio were compared to confirmed AIP diagnosis and characteristic computed tomography (CT) and magnetic resonance imaging (MRI) features (diffuse pancreatic swelling, rim-like enhancement). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated at IgG4/IgG thresholds of ≥15% and ≥20%.

Results

Our sample included a total of 60 patients with raised serum IgG4 levels. 21 patients had been diagnosed with Type 1 AIP, and 39 patients had not.
The majority of our patients had serum IgG4 ≥135 mg/dL (n=53, 88.3%). However, there was no significant association between the conventional serum IgG4 cut off of ≥135 mg/dL and the diagnosis of AIP (p = 0.687). In contrast, serum IgG4/IgG ratio demonstrated significantly higher values in patients with AIP compared to those without (median 23.2% vs 13.9%; p < 0.001). Analysis by logistic regression of IgG4/IgG ratio showed an acceptable performance with an area under the curve of 0.779, sensitivity of 92.3%, and specificity of 52.4%.

Variable	Type 1 AIP Present (n=21)	Type 1 AIP Absent (n=39)	Test Statistic	p-value
IgG4/IgG ratio	23.2 (24.0 ± 14.2)	13.9 (13.4 ± 4.5)	U = 184	<0.001
Serum IgG4 ≥135 mg/dL	18/21 (85.7%)	35/39 (89.7%)	Fisher's exact	0.687

We performed further analysis to determine a threshold for diagnostic utility of serum IgG4/IgG ratio. A ratio of ≥20% was strongly associated with AIP diagnosis (OR = 13.2, 95% CI: 3.08–56.5; p < 0.001), with high specificity (92.3%) and PPV (78.6%). Reducing the diagnostic threshold to ≥15% increased sensitivity to 76.2% (vs 52.4% at ≥20%) and improved NPV 84.4%, however this reduced specificity to 69.2%.

Subset analysis was performed among patients with Type 1 AIP (n=21) to evaluate for relationship between serum biomarkers and typical imaging findings (diffuse pancreatic swelling, rim-like enhancement). When stratified to a cut off of ≥135 mg/dL, the association between serum IgG4 levels with imaging findings trended towards positivity, but was not statistically significant (OR 3.14, p = 0.0553, φ 0.196). The IgG4/IgG ratio demonstrated a stronger association with typical imaging findings, although still not achieving statistical significance (OR = 1.065, p = 0.129). This subset analysis is likely limited by the small sample size.

Conclusion

This study demonstrates that serum IgG4/IgG ratio is a superior serological marker compared to serum IgG4 alone, particularly in the diagnosis of type 1 AIP. A threshold ratio of ≥20% demonstrated strong association with AIP diagnosis, with high specificity and PPV.
Our findings support the incorporation of IgG4/IgG ratio - particularly at a cut-off of 20% - as a valuable adjunct in diagnosis of suspected type 1 AIP, and we recommend further research in a larger cohort to validate this data.

References

1. Wallace ZS, Naden RP, Chari S, Choi HK, Della-Torre E, Dicaire JF, et al. The 2019 American College of Rheumatology/European League Against Rheumatism classification criteria for IgG4-related disease. Arthritis Rheumatol. 2020;72(1):7–19.
2. Umehara H, Okazaki K, Kawa S, Takahashi H, Yoshino T, Matsui S, et al. The 2020 revised comprehensive diagnostic (RCD) criteria for IgG4-related disease. Mod Rheumatol. 2021;31(3):529–33.
3. Lanzillotta M, Mancuso G, Della-Torre E. Advances in the diagnosis and management of IgG4-related disease. BMJ. 2020;369:m1067.
4. Uchida K, Okazaki K. Current status of type 1 (IgG4-related) autoimmune pancreatitis. J Gastroenterol. 2022;57(10):695–708.
5. Xia CS, Zhang S, Duan L, Zhao CW, Zhang F. Diagnostic performances of serum IgG4 concentration and IgG4/IgG ratio in IgG4-related disease. Clin Rheumatol. 2017;36(11):2769–74.

Introduction

Acute pancreatitis (AP) is associated with an intense catabolic, local-regional and systemic inflammatory state, which can lead to changes in body composition, with prognostic implications.

Aims & Methods

Aims: To evaluate the body composition by anthropometry, bioelectrical impedance analysis (BIA) and computed tomography (CT) and its influence in AP severity, endocrine insufficiency (EnPI-AP), pancreatic exocrine (EPI-AP) and post-pancreatic enzyme replacement therapy (PERT).
Methods: Prospective longitudinal study of consecutive adult patients diagnosed with first AP episode. EPI-AP patients were randomized to receive PERT (4000IU/meal+20000IU/snack) vs. placebo (clinicaltrials.gov:NCT05480241). Body composition was assessed using anthropometry, BIA (InBody 570) and CT (cross-sectional areas L1/L3). Obesity was diagnosed for body mass index (BMI)≥30Kg/m², waist-to-hip ratio (WHR)>0.9(men)/0.85(women) and percentage total fat mass (TFM)>20%(men)/28%(women). Visceral obesity was defined by abdominal circumference (AC)>94(men)/80(women)cm, visceral fat area (VFA)≥100cm² and visceral/subcutaneous fat ratio (VSFR)≥0.4. Sarcopenia was diagnosed by skeletal muscle mass (SMM)<20(men)/15(women)Kg, SMM index (SMMi)<7.0/5.5Kg/m² and skeletal muscle area index (SMAi)<41(men)/38.5(women)cm². The three methods were correlated using spearman test and Bland-Altman plots.

Results

A total of 105 patients (65.7%(n=69) males; mean age:63.8±17.1yo) were enrolled and followed-up. AP was moderately-severe/severe in 32.4%/16.2%. EPI-AP and EnPI-AP occurred in 47.6%(n=50) and 17.1%(n=18). EPI-AP was persistent (≥6months after AP diagnosis) in 58%. After 6-month post-randomization, 44%(n=11/25) under PERT and 40%(n=10/25) under placebo resolved EPI-AP (p=0.598).
Obesity was diagnosed in 19.0%(n=20) by BMI, 97.1%(n=102)/72.4%(n=76) by WHR in antropometry/BIA, and 57.1%(n=60) by TFM. Visceral obesity was diagnosed in 78.1%(n=82) by AC, in 41.9%(n=44)/ 97.2%(n=103) by VFM in BIA/CT and in 90.5%(n=95) by VSFR. Sarcopenia was diagnosed in 1.0%(n=1) by MMS.
Considering outcomes, moderately-severe/severe AP was strongly associated with WHR by BIA (OR=10.2; p=0.034) and VFA by BIA (OR=1.08; p=0.029) and CT (OR=1.003; p=0.038). EPI-AP was statically associated with WHR by BIA (OR=11.6; p=0.048) and SMMi by BIA (OR=77.4; p=0.048) and TFM (OR=2.3; p=0.048). Severe EPI-AP was strongly associated with VSFR (OR=20;95%CI; p=0.048) and SMMi by BIA (OR=23.2; p=0.003) and CT (OR=2.3; p=0.041). SMMi by BIA (OR=14.1; p=0.030) and CT (OR=1.6; p=0.031) predicted EnPI-AP.
For obesity, TFM by BIA had a strong correlation with BMI (r=0.61; p<0.001) and a weak correlation with WHR by anthropometry (r=0.37; p<0.001). Regarding visceral obesity, VFA by BIA was weakly correlated with WHR by anthropometry (r=0.29; p=0.004) and VFA by CT (r=0.20; p=0.045). For sarcopenia, SMM by BIA was strongly correlated with SMM by CT (r=0.78; p<0.001).
In EPI-AP patients, a significant decrease of WHR (t(52)=2.262; p=0.028) and TFM (t(53)=1.695; p=0.046) by BIA was observed after 6months of PERT.

Conclusion

Body composition is significantly changed in AP, with >2/3 of patients with obesity, especially the visceral component. Obesity, including visceral obesity, correlates with AP severity. Obesity, including visceral obesity and sarcopenia are correlated with the EPI-AP and its severity, while sarcopenia is correlated with EnPI-AP. PERT has led to a significant reduction in obesity markers. Body composition assessment by BIA (TFM, VFA and SMM) and CT (VFA and SMM) were of clinical value and comparable.

References

1. Kim J, Kim S-s, Hwang HK, Kang CM, Kim KS, Kim SH. Body composition assessment using bioelectrical impedance analysis and computed tomography in patients who underwent pancreatoduodenectomy in Korea: a before and after study. Ann Nutr Metab 2023;15(3):72-80.
2. Wang S, Wang M, Jiang L, Zhao X. Low skeletal muscle quality extracted from CT is associated with poor outcomes in severe acute pancreatitis patients. Eur J Radiol 2024;170:111215.
3. Zhou Y, Hao N, Duan Z, Kong M, Xu M, Zhang D, et al. Assessment of acute pancreatitis severity and prognosis with CT-measured body composition. Int J Gen Med 2021;14:3971-3980.
4. Chaigneau T, Morello R, Vannier E, Musikas M, Piquet M-A, Vupont B. Impact of sarcopenic obesity on predicting the severity of acute pancreatitis. Did Liver Dis 2023;55(7):926-932.

Introduction

Despite advances with chemotherapy regimens, Pancreatic adenocarcinoma (PDAC) is becoming the 2^nd cause of cancer-related death. Personalized medicine will be the game changer, but molecular characterization of pancreatic neoplasms is yet extremely cumbersome and has been performed on surgical samples or few EUS-tissue acquisition (TA) cases, mostly for DNA analysis. Our aim was to evaluate DNA and RNA extracted for research purposes from pancreatic neoplasms employing Endoscopic Ultrasound (EUS) Fine needle aspiration (FNA) and biopsy (FNB) and adequacy to molecular analyses.

Aims & Methods

From Oct 2022, patients with solid pancreatic neoplasms suggestive of either PDAC or neuroendocrine neoplasm (NEN) undergoing diagnostic EUS-TA were considered for enrollment. Employed needles were either FNA, or Franseen, Fork-tip or Three-prong, either 22G or 25G based on operator’s preference, with Rapid on Site Evaluation and, in case of adequacy within the first 2 passes, 1 additional pass with the same needle was performed for molecular analyses. DNA and RNA were then extracted with a new technique and nucleic acids were quantified and evaluated for adequacy for molecular analysis. Mann-Whitney was employed for comparison of continuous variables, and Kruskal-Wallis test for comparison between multiple groups; Logistic regression was applied to determine factors associated with adequacy to molecular tests.

Results

351 patients underwent sampling for molecular analyses, 309 with a definitive diagnosis of PDAC and 42 with NEN. 92,9% of patients were sampled with 25G FNA needles. Median quantity of DNA extracted was significantly lower in PDAC 2048 ng (95%CI: 1470 -3651) compared to NEN 6752 ng (95%CI: 3502-9655)(p<0.0144). Mean quantity of RNA extracted was similar, 312 ng for PDAC, and 444 ng for NEN (p=0.07), with a higher median RIN of 6,4 (95%CI:6,2-6,5) for PDAC versus 4,7 (95%CI:3,9-5) for NEN (p<0.0001). In terms of needle type, concerning DNA extraction, 25G FNA needles retrieved a median of 3384 ng, 25G Franseen needles (4312 ng), 22G Franseen (73864 ng), 25G Fork-tip or Three-prong (3104 ng), with no significant difference. In terms of needle type, concerning RNA extraction, 25G FNA needles retrieved a median of 310 ng (RIN 6,3), 25G Franseen needles 460 ng (RIN 5,5), 22G Franseen 884 ng (RIN 5,9), 25G Fork-tip or Three-prong 301 ng (RIN 5,15), with no significant difference. 295 (95,5%) of PDAC samples and 34 (80,9%) of NEN samples were considered adequate for sequencing. The only factor associated to adequacy for molecular analysis was tumor type, with PDAC having an OR of 5,44 (95%CI 2,06-14,37)(p=0.0006), while the type of employed needle was not

Conclusion

Molecular analysis on EUS-acquired tissue of pancreatic neoplasms will be the mainstay of personalized therapies but how to best perform tissue acquisition and sample handling for this specific purpose is yet to be defined. This is the largest study ever performed on DNA and RNA extraction from EUS-acquired samples, demonstrating superior adequacy for molecular analysis in PDAC compared to NEN. All needle types result similar in terms of performance despite the low number of needles other than 25G FNA needles.