Laparoscopic versus open pancreaticoduodenectomy for ampullary cancer: A retrospective study.

INTRODUCTION: Studies comparing laparoscopic pancreaticoduodenectomy (LPD) with open pancreaticoduodenectomy (OPD) for ampullary carcinoma (AC) are limited. This study aimed to compare short- and long-term outcomes between LPD and OPD for AC. METHODS: This study included patients with AC who underwent pancreaticoduodenectomy (PD) with curative intention at Ogaki Municipal Hospital from April 2008 to March 2023. RESULTS: Fifty-five patients underwent LPD (n = 26) or OPD (n = 29). There were no significant differences in the demographics between the two groups. The LPD group had a significantly longer operative time (268 vs. 225 min), less blood loss (125 vs. 450 mL), and shorter postoperative hospital stay (18 vs. 23 days) than the OPD group. There was no significant difference in the morbidity ratio. Fewer lymph nodes were harvested in the LPD group than OPD group (9.5 vs. 16.0), but there were no significant differences in lymph node metastasis or pathological stages. There were no significant differences in overall survival (OS) or recurrence-free survival (RFS). The 3- and 5-year OS rates in the LPD group and the OPD group were 63.0% and 54%, 64.8%, and 61.2%, respectively. The 3- and 5-year RFS rates were 57.4% and 57.4%, 58.1%, and 54.4%, respectively. CONCLUSIONS: LPD for AC had short- and long-term outcomes comparable with those of OPD. LPD could be considered the standard treatments for AC because of less blood loss and a shorter hospital stay.

Does the textbook outcome in pancreatic surgery score after pancreaticoduodenectomy for ampullary carcinoma have prognostic value?

BACKGROUND: The value of the textbook outcome in pancreatic surgery (TOPS) score, a composite measure of surgical performance for quality assurance, was evaluated in a South African tertiary hospital cohort of pancreaticoduodenectomies (PD) performed for adenocarcinoma of the ampulla of Vater (AAV). METHODS: A review of all patients undergoing a PD for AAV at a single centre between January 1999 and December 2023 was performed. Demographic, operative, pathological and postoperative variables were recorded. Ten clinical and histological variables were used to construct a TOPS score. These included an R0 resection, no postoperative pancreatic fistula (POPF), no bile leak, no post-pancreatectomy haemorrhage, no delayed gastric emptying, no major postoperative complications (< Gr 3 Clavien-Dindo), no readmission to ICU, length of stay ≤ 10 days, no 30-day readmission or intervention and no 30-day mortality. A textbook outcome (TO) was defined as the fulfilment of all 10 variables. In patients in whom TO was not achieved, the reasons for failure were identified. In addition, the number of patients who had major complications and died were categorised as failure to rescue (FTR). RESULTS: A positive TOPS score was achieved in 27 of 79 (34.2%) patients undergoing a PD. Overall five-year survival after PD was 33.9%. TOPS conferred a significant 1-year survival benefit, 88.9% vs 66.7% (OR 4.12, 95% CI 1.08-15.67, p = 0.038). There was no significant difference in 5-year survival between TOPS and non-TOPS patients, 40.0% vs 32.4% (OR 1.39, 95% CI 0.48-3.99, p = 0.54). A POPF occurred in 31.6% patients, resulting in a significantly longer hospital admission, 17 vs 10 days (95% CI 2.66-11.34, p = 0.0019). Twenty-one (26.6%) patients developed a major complication, five of whom died (FTR = 6.3%). CONCLUSION: This study confirmed the value of TOPS as a useful measurement to assess hospital quality metrics and short-term survival after PD for AAV. One quarter of patients developed a major complication with a 6.3% FTR.

Preoperative profiles of plasma amino acids and derivatives distinguish periampullary cancer and benign disease.

Periampullary cancers, including pancreatic ductal adenocarcinoma, ampullary-, cholangio-, and duodenal carcinoma, are frequently diagnosed in an advanced stage and are associated with poor overall survival. They are difficult to differentiate from each other and challenging to distinguish from benign periampullary disease preoperatively. To improve the preoperative diagnostics of periampullary neoplasms, clinical or biological markers are warranted.In this study, 28 blood plasma amino acids and derivatives from preoperative patients with benign (N = 45) and malignant (N = 72) periampullary disease were analyzed by LC-MS/MS.Principal component analysis and consensus clustering both separated the patients with cancer and the patients with benign disease. Glutamic acid had significantly higher plasma expression and 15 other metabolites significantly lower plasma expression in patients with malignant disease compared with patients having benign disease. Phenylalanine was the only metabolite associated with improved overall survival (HR = 0.50, CI 0.30-0.83, P < 0.01).Taken together, plasma metabolite profiles from patients with malignant and benign periampullary disease were significantly different and have the potential to distinguish malignant from benign disease preoperatively.

Clinical Significance of MUC4 and Associated Proteins in Pancreatic and Periampullary Cancers.

OBJECTIVE: This study primarily aimed to assess the expression of MUC4 in patients with pancreatic ductal adenocarcinoma (PDAC) as compared with controls and assess its clinical relevance. MATERIALS AND METHODS: Serum MUC4 levels and MUC4 gene expression in snap-frozen tissue were analyzed through surface plasmon resonance and quantitative polymerase chain reaction, respectively. Tumor tissues and control tissues were analyzed for MUC4 and other mucins through immunohistochemistry. RESULT: MUC4 expression in tumor tissue was found to be significantly elevated in PDAC patients as compared with chronic pancreatitis tissues and normal pancreatic tissues. Periampullary carcinoma and cholangiocarcinoma tissue also showed increased expression of MUC4 and other mucins. CONCLUSIONS: Differential expression of MUC4 in pancreatic tumor tissues can help to differentiate PDAC from benign conditions.

The road to tailored adjuvant chemotherapy for all four non-pancreatic periampullary cancers: An international multimethod cohort study.

BACKGROUND: Despite differences in tumour behaviour and characteristics between duodenal adenocarcinoma (DAC), the intestinal (AmpIT) and pancreatobiliary (AmpPB) subtype of ampullary adenocarcinoma and distal cholangiocarcinoma (dCCA), the effect of adjuvant chemotherapy (ACT) on these cancers, as well as the optimal ACT regimen, has not been comprehensively assessed. This study aims to assess the influence of tailored ACT on DAC, dCCA, AmpIT, and AmpPB. PATIENTS AND METHODS: Patients after pancreatoduodenectomy for non-pancreatic periampullary adenocarcinoma were identified and collected from 36 tertiary centres between 2010 - 2021. Per non-pancreatic periampullary tumour type, the effect of adjuvant chemotherapy and the main relevant regimens of adjuvant chemotherapy were compared. The primary outcome was overall survival (OS). RESULTS: The study included a total of 2866 patients with DAC (n = 330), AmpIT (n = 765), AmpPB (n = 819), and dCCA (n = 952). Among them, 1329 received ACT, and 1537 did not. ACT was associated with significant improvement in OS for AmpPB (P = 0.004) and dCCA (P < 0.001). Moreover, for patients with dCCA, capecitabine mono ACT provided the greatest OS benefit compared to gemcitabine (P = 0.004) and gemcitabine - cisplatin (P = 0.001). For patients with AmpPB, no superior ACT regime was found (P > 0.226). ACT was not associated with improved OS for DAC and AmpIT (P = 0.113 and P = 0.445, respectively). DISCUSSION: Patients with resected AmpPB and dCCA appear to benefit from ACT. While the optimal ACT for AmpPB remains undetermined, it appears that dCCA shows the most favourable response to capecitabine monotherapy. Tailored adjuvant treatments are essential for enhancing prognosis across all four non-pancreatic periampullary adenocarcinomas.

Long-term Outcomes of Ampullary Adenoma According to Resected Margin Status after Endoscopic Papillectomy.

Background/Aims: : Endoscopic papillectomy (EP) is increasingly used as an alternative to surgery for managing benign ampullary neoplasms. However, post-EP resection margins are often positive or indeterminate, and there is no consensus on the management of ampullary adenomas with positive or indeterminate margins after EP. This study was designed to compare the long-term outcomes between resected margin-negative (RMN) and resected margin-positive/indeterminate (RMPI) groups and to identify factors associated with clinical outcomes. Methods: : This retrospective analysis included patients with ampullary adenoma without evidence of adenocarcinoma who underwent EP between 2004 and 2016. The RMN and RMPI groups were compared for recurrence rates and recurrence-free duration during a mean follow-up duration of 71.7±39.8 months. Factors related to clinical outcomes were identified using multivariate analysis. Results: : Of the 129 patients who underwent EP, 82 were in the RMN group and 47 were in the RMPI group. The RMPI group exhibited a higher recurrence rate compared to the RMN group (14.6% vs 34.0%, p=0.019). However, the recurrence-free duration was not significantly different between the groups (34.7±32.6 months vs 36.2±27.4 months, p=0.900). Endoscopic treatment successfully managed recurrence in both groups (75% vs 75%). Submucosal injection was a significant risk factor for residual lesions (hazard ratio, 4.11; p=0.009) and recurrence (hazard ratio, 2.57; p=0.021). Conclusions: : Although ampullary adenomas with positive or indeterminate margins after EP showed a higher rate of recurrence at long-term follow-up, endoscopic treatment was effective with favorable long-term outcomes. Submucosal injection prior to resection was associated with increased risk of recurrence and residual lesions.

Clinicopathologic Analysis and Prognostic Factors for Survival in Patients with Operable Ampullary Carcinoma: A Multi-Institutional Retrospective Experience.

Background and Objectives: In ampullary cancer, 5-year survival rates are 30-50%, even with optimal resection and perioperative systemic therapies. We sought to determine the important clinicopathological features and adjuvant treatments in terms of the prognosis of patients with operable-stage ampullary carcinomas. Materials and Methods: We included 197 patients who underwent pancreaticoduodenectomy to treat ampullary carcinomas between December 2003 and May 2019. Demographics, clinical features, treatments, and outcomes/survival were analyzed. Results: The median disease-free survival (mDFS) and median overall survival (mOS) were 40.9 vs. 63.4 months, respectively. The mDFS was significantly lower in patients with lymphovascular invasion (p < 0.001) and lymph node involvement (p = 0.027). Potential predictors of decreased OS on univariate analysis included age ≥ 50 years (p = 0.045), poor performance status (p = 0.048), weight loss (p = 0.045), T3-T4 tumors (p = 0.018), surgical margin positivity (p = 0.01), lymph node involvement (p = 0.001), lymphovascular invasion (p < 0.001), perineural invasion (p = 0.007), and poor histological grade (p = 0.042). For the multivariate analysis, only nodal status (hazard ratio [HR]1.98; 95% confidence interval [CI], 1.08-3.65; p = 0.027) and surgical margin status (HR 2.61; 95% CI, 1.09-6.24; p = 0.03) were associated with OS. Conclusions: Nodal status and a positive surgical margin were independent predictors of a poor mOS for patients with ampullary carcinomas. Additional studies are required to explore the role of adjuvant therapy in patients with ampullary carcinomas.

Comparison of the two histological subtypes of ampullary adenocarcinoma: a retrospective study.

OBJECTIVES: This study aimed to compare the intestinal and pancreatobiliary subtypes of ampullary adenocarcinoma in a large patient group due to limited data on survival and risk factors. METHODS: A retrospective analysis of the clinical and pathological findings and the survival of 184 patients with ampullary adenocarcinoma who underwent curative operation between 2007 and 2018 was performed. RESULTS: Pancreatobiliary subtype had a higher prevalence of jaundice before operation than the intestinal subtype (p < 0.05). Pancreatobiliary subtype had a larger tumor size (> 2 mm) (p < 0.01) and poorer differentiation (p < 0.05) than the intestinal subtype. Perineural invasion more frequently occurred in pancreatobiliary subtype than the intestinal subtype (p < 0.01) and pancreatobiliary subtype had a higher prevalence of positive dissected lymph nodes (p < 0.05) with an advanced disease stage (p < 0.01) than the intestinal subtype. Patients of the pancreatobiliary subtype had poorer disease-free and overall survival than patients of the intestinal subtype. No survival benefit of adjuvant chemotherapy was found in either patients of the intestinal subtype or pancreatobiliary subtype. No significant difference was found in any subtypes regarding the recurrent regions. CONCLUSIONS: Pancreatobiliary subtype exhibited a higher recurrence rate and a poorer overall survival rate with more unfavorable pathological characteristics than the intestinal subtype.

OBJETIVOS: Los datos sobre la supervivencia y los factores de riesgo del adenocarcinoma ampular son limitados debido a su rareza. Este estudio buscó comparar el subtipo intestinal y el subtipo pancreático-biliar en pacientes con adenocarcinoma ampular. MÉTODOS: Análisis retrospectivo de hallazgos clínicos y patológicos y la supervivencia de 184 pacientes con adenocarcinoma ampular tratados entre 2007 y 2018. RESULTADOS: El subtipo pancreático-biliar tuvo una mayor prevalencia de ictericia antes de la operación y un tamaño de tumor mayor, y una peor diferenciación, que el subtipo intestinal. La invasión perineural fue más frecuente en el subtipo pancreático-biliar, con una mayor prevalencia de linfonodos disecados positivos y un estadio avanzado de la enfermedad. Los pacientes del subtipo pancreático-biliar tuvieron una supervivencia libre de enfermedad y una supervivencia general peores que los pacientes del subtipo intestinal. No se encontró ningún beneficio de la quimioterapia adyuvante en pacientes del subtipo intestinal o pancreático-biliar. No hubo diferencia significativa en las regiones recurrentes. CONCLUSIÓN: El subtipo pancreático-biliar mostró una tasa de recurrencia y una tasa de supervivencia general peores, con características patológicas más desfavorables que el subtipo intestinal.

Real-world efficacy and safety of capecitabine with oxaliplatin in patients with advanced adenocarcinoma of the ampulla of Vater.

BACKGROUND: Adenocarcinoma of the ampulla of Vater (AoV) is one of the rare periampullary cancers, and due to its anatomical location, it is categorized into various histologic subtypes. Its rarity and diversity pose challenges in treatment decision-making for patients with advanced AoV carcinoma. This study investigated the efficacy and safety of the combined regimen of capecitabine and oxaliplatin (CAPOX) in a real-world clinical setting. METHODS: This investigation encompassed patients with advanced AoV carcinoma who underwent CAPOX treatment. Histologic phenotypes were identified through a combination of histopathological analysis and protein expression markers, including MUC1, CDX2, CK20, and MUC2. The correlation between histopathological determinants and survival outcomes was explored, in addition to an evaluation of the safety profile of CAPOX therapy. RESULTS: From January 2010 to June 2023, 42 patients received CAPOX. Of these, 14 patients (33.3%) had not received any prior palliative chemotherapy, while 28 patients (66.7%) had undergone one prior line of chemotherapy. At a median follow up of 9.0 months, the median progression-free survival (PFS) was 4.38 months (95% CI, 2.78-5.69) and the median overall survival (OS) was 9.57 months (95% CI 7.56-11.6). The objective response and disease control rates were 38.1% and 61.9%, respectively. Patients who received CAPOX as a second-line treatment had poorer PFS (HR = 2.62; 95% CI, 1.49-4.90, p = 0.003) and OS (HR = 2.82, 95% CI, 1.47-5.38, p = 0.001) compared to those who received CAPOX as a first-line chemotherapy. There were no statistically significant differences in PFS (p = 0.185) and OS (p = 0.097) between groups based on histologic subtypes. Neutropenia (14.3%) emerged as the predominant grade 3-4 toxicity. Notably, treatment cessation occurred in select instances owing to grade 3 fatigue (9.5%) and peripheral neuropathy (9.5%). CONCLUSIONS: This study confirmed the therapeutic efficacy and safety of CAPOX in a real-world setting, consistent with prior phase II trial results. While CAPOX proved feasible for advanced AoV carcinoma regardless of histologic subtype, its reduced effectiveness in second-line settings necessitates further research to determine its optimal palliative use.

Metastatic Melanoma of the Common Bile Duct Presented with Dyspepsia.

Malignant melanoma (MM) is an aggressive tumor that can metastasize to any organ, but biliary tract metastasis is scarce. We describe a very rare case of MM metastasis to the common bile duct (CBD), presented with only dyspeptic symptoms. The patient had mildly elevated alkaline phosphatase and gamma-glutamyl transferase levels. Magnetic resonance cholangiopancreatography demonstrated a dilated common bile duct with a distal stricture. The MM diagnosis was established with the ampulla of Vater biopsy specimens obtained by endoscopic retrograde cholangiopancreatography (ERCP), and the patient's symptoms were resolved after biliary stenting. Both primary CBD cancer and other cancer types like MM that metastasize to CBD can cause obstruction and can be manifested only by dyspeptic symptoms. MM metastasis to CBD can cause obstruction manifested only by dyspeptic symptoms without obstructive jaundice. ERCP can be employed as a promising option for treatment and diagnosis. New-onset dyspeptic symptoms in patients with a history of MM should be investigated thoroughly, especially in the context of biliary metastasis.

Differences in Lymph Node Metastases Patterns Among Non-pancreatic Periampullary Cancers and Histologic Subtypes: An International Multicenter Retrospective Cohort Study and Systematic Review.

BACKGROUND: Standard lymphadenectomy for pancreatoduodenectomy is defined for pancreatic ductal adenocarcinoma and adopted for patients with non-pancreatic periampullary cancer (NPPC), ampullary adenocarcinoma (AAC), distal cholangiocarcinoma (dCCA), or duodenal adenocarcinoma (DAC). This study aimed to compare the patterns of lymph node metastases among the different NPPCs in a large series and in a systematic review to guide the discussion on surgical lymphadenectomy and pathology assessment. METHODS: This retrospective cohort study included patients after pancreatoduodenectomy for NPPC with at least one lymph node metastasis (2010-2021) from 24 centers in nine countries. The primary outcome was identification of lymph node stations affected in case of a lymph node metastasis per NPPC. A separate systematic review included studies on lymph node metastases patterns of AAC, dCCA, and DAC. RESULTS: The study included 2367 patients, of whom 1535 had AAC, 616 had dCCA, and 216 had DAC. More patients with pancreatobiliary type AAC had one or more lymph node metastasis (67.2% vs 44.8%; P < 0.001) compared with intestinal-type, but no differences in metastasis pattern were observed. Stations 13 and 17 were most frequently involved (95%, 94%, and 90%). Whereas dCCA metastasized more frequently to station 12 (13.0% vs 6.4% and 7.0%, P = 0.005), DAC metastasized more frequently to stations 6 (5.0% vs 0% and 2.7%; P < 0.001) and 14 (17.0% vs 8.4% and 11.7%, P = 0.015). CONCLUSION: This study is the first to comprehensively demonstrate the differences and similarities in lymph node metastases spread among NPPCs, to identify the existing research gaps, and to underscore the importance of standardized lymphadenectomy and pathologic assessment for AAC, dCCA, and DAC.

[Efficacy analysis of 7 cases of mixed neuroendocrine-nonneuroendocrine neoplasm of the duodenal papilla].

The clinical data of 7 patients diagnosed with mixed neuroendocrine-nonneuroendocrine neoplasm were analyzed in the Department of Hepatobiliary Surgery of Hunan Provincial People's Hospital from January 2016 to December 2022. Among the 7 patients, 5 were male and 2 were female, with an average age of 59.3 years. Its clinical characteristics are similar to malignant ampulla tumors, and it is difficult to differentiate them. The preoperative puncture biopsy positivity rate is low, making it difficult to diagnose preoperatively, and the prognosis is worse.Comprehensive treatment including surgery, chemotherapy, and radiotherapy can be the preferred treatment option for this disease.

A rare case of neuroendocrine cell tumor mixed with a mucinous component in the ampulla of Vater.

BACKGROUND: A rare case of neuroendocrine cell tumor (NET) having both conventional and mucinous components was reported. Mucinous NET is rarely encountered in the pathological diagnosis of gastrointestinal (GI) tumors. Here we examined the mechanism for transformation of conventional NETs into mucinous NETs. CASE PRESENTATION: Macroscopic examination revealed a tumor with ulceration in the ampulla of Vater that measured 1.7 cm in its largest diameter. Histologically, the tumor comprised two components: a tubular/ribbon-like feature and small nests floating in a mucinous lake. The tumor nests showed sheet, nest and ribbon-like structures of small cells having eosinophilic cytoplasm as well as small-sized nuclei with dense hyperchromatin. Immunohistochemical analysis showed tumor cells positive for pan-endocrine markers (synaptophysin, CD56, INSM1 and chromogranin). Based on the histological findings, the solid and mucinous components were diagnosed as conventional and mucinous NETs, respectively. Grading was NET G2 based on 12.8% and 13.2% Ki-67-positive cells in the solid and mucinous components, respectively. Immunohistochemically, the mucin phenotype of this tumor was gastric and intestinal. Only the mucinous NET component had cytoplasmic CD10 expression. Examination using a customized gene panel detected only a DPC4 mutation, which was limited to the mucinous component. CONCLUSIONS: Coexistence of conventional and mucinous NETs could provide important insight into evaluating the NET subtype histogenesis. Moreover, molecular alterations including cytoplasmic expression of CD10 and the DPC4 mutation can contribute to interpretation of tumor pathogenesis.

New gel immersion endoscopic ultrasonography technique for accurate periampullary evaluation.

BACKGROUND: Visualization of the pancreatobiliary junction is one of the challenges faced by endoscopic ultrasonography (EUS). The water-filling technique, which allows for the observation of the ampulla at a suitable distance by injecting water into the lumen of the duodenum, was used for this purpose. However, a new gel immersion technique has recently been introduced for visualizing the gastrointestinal tract. This study investigated the effectiveness of visualizing the pancreatobiliary junction in EUS by comparing both water filling and the new gel immersion technique in identical cases. METHODS: The study ran from June to December 2021. Ten images from each technique were retrospectively compared by three independent researchers. The primary result of the study was the number of images depicting the "Pancreatic and Biliary Ducts Penetrating the Duodenal Muscularis Propria" (defined as Excellent observation) in each technique. The secondary outcome was defined as gel immersion technique's safety and impact on duodenal lumen distension. RESULTS: Ten patients used the gel immersion technique. All patients underwent the water-filling technique first, followed by gel injection after the water was completely aspirated. The average number of pictures rated as "Excellent observation," which is the primary outcome, was significantly higher with the gel immersion technique than with water filling, and no adverse events were observed. The subanalysis revealed that both convex and radial echoendoscopes are equally effective at depicting the ampulla with the gel immersion technique. CONCLUSIONS: The ability to depict the pancreatobiliary junction using the gel immersion technique is superior to that of the water-filling method, which may allow for a more detailed assessment of the ampullary region with both radial and convex echoendoscopes. This can be a useful EUS technique for diagnosing pancreaticobiliary maljunction or periampullary tumors.

Feasibility of new-generation endocytoscopy for the real-time diagnosis of ampullary lesions: A pilot study (with video).

BACKGROUND AND AIM: An early and accurate diagnosis of ampullary neoplasia is crucial; however, sampling bias is still a major concern. New-generation endocytoscopy enables real-time visualization of cellular structures and enables an accurate pathological prediction; however, its feasibility for small ampullary lesions has never been investigated. METHODS: We developed a novel endocytoscopic (EC) classification system for ampullary lesions after an expert review and agreement from five experienced endoscopists and one pathologist. We then consecutively enrolled a total of 43 patients with an enlarged ampulla (< 3 cm), all of whom received an endocytoscopic examination. The feasibility of endocytoscopy was evaluated, and the performance of the EC classification system was then correlated with the final histopathology. RESULTS: In five cases (11.6%), the endocytoscope could not approach the ampulla, and these cases were defined as technical failure. Among the remaining 38 patients, 8 had histopathology-confirmed adenocarcinoma, 15 had adenoma, and 15 had non-neoplastic lesions. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the EC classification system to diagnose ampullary neoplasias were 95.7%, 86.7%, 91.7%, 92.9%, and 92.1%, respectively. Moreover, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the EC classification to diagnose ampullary cancer were 62.5%, 100%, 100%, 90.9%, and 92.1%, respectively. One case with intra-ampullary papillary-tubular carcinoma was classified as having a non-neoplastic lesion by endocytoscopy. CONCLUSIONS: Endocytoscopy and the novel EC classification system demonstrated good feasibility to discriminate ampullary neoplasias from non-neoplastic lesions and may be useful for optical biopsies of clinically suspicious ampullary lesions.

Prognostic value of nodal staging classification and number of examined lymph nodes among patients with ampullary cancer.

BACKGROUND: Metastatic disease in the regional lymph nodes (LNs) is a strong indicator of worse outcomes among patients after curative-intent resection of ampullary cancer (AC). This study aimed to ascertain the threshold number of examined LNs (ELNs) for AC to compare the prognosis accuracy of various nodal classification schemes relative to long-term prognosis. METHODS: Patients who underwent pancreatoduodenectomy (PD) for AC (2004-2019) were identified using the National Cancer Database. Locally weighted regression scatter plot smoothing (LOWESS) curves were used to ascertain the optimal cut point for ELNs. The accuracy of the American Joint Committee on Cancer N classification, LN ratio, and log odds transformation (LODDS) ratio to stratify patients relative to survival was examined. RESULTS: Among 8127 patients with AC, 67% were male with a median age of 67 years (IQR, 59-74). Tumors were most frequently classified as T3 (34.9%), followed by T2 (30.6%); T1 (12.9%) and T4 (17.6%) were less common. LN metastasis was identified in 4606 patients (56.7%). Among patients with nodal disease, 37.0% and 19.7% had N1 and N2 disease, respectively. The LOWESS curves identified an inflection cutoff point in the hazard of survival at 20 ELNs. The survival benefit of 20 ELNs was more pronounced among patients without LN metastasis vs patients with N1 disease (median overall survival [OS]: 54.1 months [IQR, 45.9-62.1] in ≥20 ELNs vs 39.0 months [IQR, 35.8-42.2] in <20 ELNs; P < .001) or N2 disease (median OS: 22.5 months [IQR, 18.9-26.2] in ≥20 ELNs vs 25.4 months [IQR, 23.3-27.6] in <20 ELNs; P < .001). When comparing the 4 different N classification schemes, the LODDS classification scheme yielded the highest predictive ability. CONCLUSIONS: Evaluation of a minimum of 20 LNs was needed to stratify patients with AC relative to the prognosis and to minimize stage migration. The LODDS nodal classification scheme had the highest prognostic accuracy to differentiate survival among patients after PD for AC.