Regional Lymphadenectomy Research Articles

Intra-Operative Tumour Detection and Staging in Pancreatic Cancer Surgery: An Integrative Review of Current Standards and Future Directions

Background: Surgical resection for pancreatic ductal adenocarcinoma (PDAC) entails the excision of the primary tumour and regional lymphadenectomy. This traditional strategy is challenged by the high rate of early recurrence, suggesting inadequate disease staging. Novel methods of intra-operative staging are needed to allow surgical resection to be tailored to the disease’s biology. Methods: A search of published articles on the PubMed and Embase databases was performed using the terms ‘pancreas’ OR ‘pancreatic’ AND ‘intra-operative staging/detection’ OR ‘guided surgery’. Articles published between January 2000 and June 2023 were included. Technologies that offered intra-operative staging and tailored treatment were curated and summarised in the following integrative review. Results: lymph node (LN) mapping and radioimmunoguided surgery have shown promising results but lacked practicality to facilitate real-time intra-operative staging for PDAC. Fluorescence-guided surgery (FGS) offers high contrast and sensitivity, enabling the identification of cancerous tissue and positive LNs with improved precision following intravenous administration of a fluorescent agent. The unique properties of optical coherence tomography and ultrasound elastography lend themselves to be platforms for virtual biopsy intra-operatively. Conclusions: Accurate intra-operative staging of PDAC, localisation of metastatic LNs, and identification of extra-pancreatic disease remain clinically unmet needs under current detection methods and staging standards. Tumour-specific FGS combined with other diagnostic and therapeutic modalities could improve tumour detection and staging in patients with PDAC.

Clinical impact of multidisciplinary team management on postoperative short-term outcomes in colorectral cancer surgery.

The multidisciplinary team (MDT) approach has become the standard for perioperative patient care. At our institution, a multidisciplinary perioperative care team called "Surgical, Nutrition and Rehabilitation Integrated Services for Excellence Team (SUNRISE)" was established for all patients with gastrointestinal cancer undergoing surgery. This study aimed to elucidate the significance of SUNRISE as a perioperative MDT by comparing short-term postoperative outcomes before and after the introduction of SUNRISE in patients with colorectal cancer. We included 181 patients diagnosed with colorectal who underwent radical surgical resection with regional lymphadenectomy. The patients were divided into two groups: the pre-SUNRISE group, consisting of 105 patients who underwent radical colorectal surgery before the introduction of the SUNRISE, and the SUNRISE group, consisting of 76 patients who underwent radical colorectal surgery after the introduction of the SUNRISE. We compared the short-term postoperative outcomes between these two groups and analyzed the risk factors affecting postoperative complications using logistic regression models. The incidence of postoperative complications in the SUNRISE group was significantly lower than that in the pre-SUNRISE group (22.4% vs. 41.0%, p = 0.011). Multivariate analysis identified the presence of SUNRISE (odds ratio, 0.33, 95% confidence interval, 0.15-0.73, p < 0.006) as an independent risk factor for postoperative complications. The median postoperative hospital stay in the SUNRISE group was significantly shorter than that in the pre-SUNRISE group (9 vs. 11days, p < 0.01). The MDT approach is useful for optimizing preoperative patient care and improving short-term postoperative outcomes in patients with colorectal cancer.

Hepatic Recurrence of Neuroendocrine Tumor Component in Gallbladder Cancer.

A 60-year-old man underwent an extended cholecystectomy with regional lymphadenectomy for T2N0M0 gallbladder cancer (GBC), which showed significant FDG uptake (SUVmax = 6.5). However, CT scan at 24 months postsurgery revealed multiple hepatic masses. Unlike the primary GBC, the hepatic masses showed limited FDG uptake (SUVmax = 3.7). A tumor biopsy revealed the diagnosis of a grade 3 neuroendocrine tumor. Furthermore, the hepatic masses showed significant uptake on somatostatin receptor scintigraphy. Upon reevaluation, the primary resected specimen was found to include approximately 10% of neuroendocrine tumor components. This case suggests that different FDG uptake between primary and metastatic cancer may necessitate differential diagnosis.

Relative Tumour Volume in Canine Oral Melanoma Staging and Prognosis.

Melanoma is one of the most common canine oral malignant tumours and is highly aggressive and metastatic, even at the early stages of development. Surgery relies on wide excision of the primary tumour and regional lymphadenectomy, with or without adjuvant therapy. Tumour location and size are important when considering staging, which ultimately affects the curative intent of surgery. Nevertheless, absolute tumour volume (TV) is not related to the vast phenotypic variability within canine breeds. This study aimed to determine the cutoff values of two ratios-tumour-to-head volume (THR) and tumour-to-body volume (TBR)-and assess whether they could be associated with the odds of finding metastasis at presentation and/or the likelihood of achieving tumour-free excision margins. A retrospective case series involving 51 dogs was used to evaluate the preoperative head/neck and chest computed tomography and histopathology of the primary mass and excised lymph nodes. Higher TV, THR% and TBR% values were associated with bone lysis and mitotic count (MC). The Ki67 index was significantly associated with local and distant metastases at presentation, whereas MC was associated with local metastasis alone. Tumour-infiltrated surgical margins were associated with caudally located tumours, regardless of the tumour size. Dogs with lymph node metastasis at presentation were seven times more prone to have local relapse. TV, THR% and TBR% values were positively associated with local lymph node metastasis at presentation. Cutoff values for both TV and TBR% were proposed to predict lymph node metastasis at presentation (TV = 6.423 cm3 and TBR% = 0.043), being supported by post-surgical survival analysis.

ASO Author Reflections: Regional Lymphadenectomy for Stomach-Preserving Surgery in Early Gastric Cancer: Is it Clinically Applicable?

ASO Author Reflections: Regional Lymphadenectomy for Stomach-Preserving Surgery in Early Gastric Cancer: Is it Clinically Applicable?

Prospective Randomized Study on the Use of Sentinel Node Biopsy for High-risk Cutaneous Squamous Cell Carcinomas of the Head and Neck.

The use of sentinel lymph node biopsy (SLNB) for high-risk cutaneous squamous cell carcinoma (CSCC) is not yet clearly documented, especially for the head and neck area, due to its rich and cross-branching lymphatic system. We present the first prospective randomized study on the use of SLNB in high-risk CSCCs of the head and neck. Seventy-six patients with high-risk CSCCs of the head and neck were randomly divided into two groups: A (n = 38) and B (n = 38). In group A, SLNB was performed additionally to the excision of squamous cell carcinoma, whereas in group B, only excision of the lesion was performed. The patients were followed up for 5 years postoperatively, and local recurrences, regional metastases (regional lymph nodes), and mortality were documented. One patient of group A, who never attended any follow-up, was excluded. Both groups had similar characteristics regarding Breslow thickness, perineurial invasion, peripheral limits, differentiation, size, previous incomplete excision, age, sex, education, sun exposure, Fitzpatrick score, previous incomplete excision, previous skin cancer, and smoking. Two patients had a positive sentinel lymph node and were submitted to regional lymphadenectomy. We documented deaths (three in group A and two in group B; P = 0.674), local recurrence (seven in group A and six in group B; P = 0.768), and regional metastasis (zero in group A and two in group B; P = 0.159). There is no clear benefit on the use of SLNB in high-risk CSCCs of the head and neck regarding metastasis, mortality, or local recurrence control.

Feasibility of Regional Lymphadenectomy for Stomach-Preserving Surgery in Early Gastric Cancer Omitting Sentinel Node Navigation: A Post Hoc Analysis of the SENORITA Trial.

Sentinel node navigation (SNN) has been known as the effective treatment for stomach-preserving surgery in early gastric cancer; however, SNN presents several technical difficulties in real practice. This study aimed to evaluate the feasibility of regional lymphadenectomy omitting SNN, using the post hoc analysis of a randomized controlled trial. Using data from the SENORITA trial that compared laparoscopic standard gastrectomy with lymphadenectomy and laparoscopic SNN, 237 patients who underwent SNN were included in this study. Tumor location was divided into longitudinal and circumferential directions. According to the location of the tumor, the presence or absence of lymph node (LN) metastases between sentinel and non-sentinel basins were analyzed. Proposed regional LN stations were defined as the closest area to the primary tumor. Sensitivities, specificities, positive predictive values, and negative predictive values (NPV) of SNN and regional lymphadenectomy were compared. Metastasis to non-sentinel basins with tumor-free in sentinel basins was observed in one patient (0.4%). The rate of LN metastasis to non-regional LN stations without regional LN metastasis was 2.5% (6/237). The sensitivity and NPV of SNN were found to be significantly higher than those of regional lymphadenectomy (96.8% vs. 80.6% [p=0.016] and 99.5% vs. 97.2% [p=0.021], respectively). This study showed that regional lymphadenectomy for stomach-preserving surgery, omitting SNN, was insufficient; therefore, SNN is required in stomach-preserving surgery.

Impact of Thoracic Duct Resection on Long-Term Survival After Esophagectomy: Individual Patient Data Meta-analysis.

Radical esophagectomy, including thoracic duct resection (TDR), has been proposed to improve regional lymphadenectomy and possibly reduce the risk of locoregional recurrence. However, because of its impact on immunoregulation, some authors have expressed concerns about its possible detrimental effect on long-term survival. The purpose of this review was to assess the influence of TDR on long-term survival. PubMed, MEDLINE, Scopus, and Web of Science databases were searched through 15 March 2024. Overall survival (OS), cancer specific survival (CSS), and disease-free survival (DFS) were primary outcomes. Restricted mean survival time difference (RMSTD), risk ratio (RR), standardized mean difference (SMD), and 95% confidence intervals (CI) were used as pooled effect size measures. The Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) methodology was employed to evaluate the certainty of evidence. The analysis included six studies with 5756 patients undergoing transthoracic esophagectomy. TDR was reported in 49.1%. Patients' ages ranged from 27 to 79 years and 86% were males. At 4-year follow-up, the multivariate meta-analysis showed similar results for the comparison noTDR versus TDR in term of OS [- 0.8 months, 95% confidence interval (CI) - 3.1, 1.3], CSS (0.1 months, 95% CI - 0.9, 1.2), and DFS (1.5 months, 95% CI - 2.6, 5.5). TDR was associated with a significantly higher number of harvested mediastinal lymph nodes (SMD 0.57, 95% CI 0.01-1.13) and higher risk of postoperative chylothorax (RR = 1.32; 95% CI 1.04-2.23). Anastomotic leak and pulmonary complications were comparable. TDR seems not to improve long-term OS, CSS, and DFS regardless of tumor stage. Routine TDR should not be routinely recommended during esophagectomy.

Role of Neo-Adjuvant Chemotherapy in Decision Making for Surgical Management of Cancer Stomach

Abstract Background Gastric cancer is the second most common cause of cancer related death worldwide. In Egypt, gastric cancer is the 12th most common cancer. The incidence rises with age and 55% of cases occur between 50 and 70 years of age. The complete resection partial or total gastrectomy is based on tumor location, stage, histology, and surgical margins. The extent of regional lymphadenectomy required has been a matter of debate. Neo-adjuvant chemotherapy could increase the curative resection rate, improve the tumor down staging possibilities. Aim of Work assess the role of the neo-adjuvant chemotherapy for surgical management of gastric cancer patients. Patients and Methods A prospective analysis of sixty patients with ranging age (18-60 years) who are diagnosed with gastric adenocarcinoma, received neo-adjuvant chemotherapy patients with minimal follow up 16 months, treated at the upper gastro-intestinal surgeries unit, Ain Shams University Hospitals. Primary end points include assessing overall survival, R0 resection rate, local recurrence, rate of pathological complete response. Results Patients aged (22-60 years old), mean age 46.67 ±12.76, the median DFS was 6 months, the mean OS is 26.3 months, recorded 1 year, 2 years OS rate was 75.8% and 67.9% respectively. However, the median OS was not reached. Conclusion This study favors the idea of Neo-adjuvant chemotherapy usage prior to surgical intervention in multiple stages of gastric cancer. However, there were other studies that questions its role and demand a reconsideration about the clinical outcome which require further investigation.

Impact of sentinel node use in lymphedema formation among gynecologic cancer patients.

The most common surgical procedure associated with lymphedema formation is the regional lymphadenectomy. One of the advantages of sentinel node biopsy is the reduction of the risk of lymphedema formation. The purpose of this review is to collect and analyze the most relevant and recent evidence of the use of sentinel node biopsy and its implication on the development of postoperative lymphedema in gynecological cancer. The current evidence of the use of sentinel node biopsy in cervical cancer to reduce lymphedema is heterogeneous and more data is needed to establish its role.Sentinel lymph node biopsy in endometrial cancer is a staging procedure with lower surgical complications, as well as lymphedema formation; while the results of prospective trials evaluating its impact on quality of life are still lacking.Sentinel lymph node biopsy in vulvar cancer minimizes the need for extensive dissection and reduces the incidence of complications associated with overharvesting of lymph nodes such as lymphedema without compromising oncological outcomes. The prevalence of lymphedema in gynecological cancer varies based on the surgical treatment or additional therapies applied. Over the past years, one of the most important surgical modifications to decrease lymphedema formation has been implementation of sentinel lymph node technique mainly in vulvar cancer patients.

Robotic subtotal left pancreatectomy with preservation of the bile duct and spleen for multifocal pancreatic metastases: a video vignette of organ-sparing pancreatectomy for tumors that do not require regional lymphadenectomy.

Pancreatectomy for pancreatic metastases (PM) yields acceptable survival outcomes in selected renal cell carcinoma (RCC) patients. We describe a technique for robotic subtotal left pancreatectomy with preservation of the common bile duct (CBD) and spleen in a patient with multifocal RCC-PM. The patient, who had RCC and underwent nephrectomy 20 years ago, presented with a pancreatic mass. Computed tomography and endoscopic ultrasonography demonstrated one mass at the head of pancreas (HOP), and other three lesions at neck, body, and tail. HOP lesion located near CBD. Subtotal left pancreatectomy was more preferred option than total pancreatectomy due to better endocrine function. The ultrasound-guided CBD and uncinate-preserving resection started at HOP, and then continued with distal pancreatectomy. The pathology revealed metastatic RCC with a negative margin. The patient experienced only biochemical pancreatic leakage. One month after surgery, the patient only required oral medication for diabetes treatment. In conclusion, the robot-assisted technique is helpful in increasing the success rate of organ-sparing pancreatectomy.

Prognostic value of combined psoas muscle mass and controlling nutritional status in patients with pancreatic ductal adenocarcinoma: a retrospective cohort study.

Pancreatic ductal carcinoma (PDAC) is an extremely poor prognostic disease. Even though multidisciplinary treatment for PDAC has developed, supportive therapies, such as nutritional therapy or perioperative rehabilitation to sustain and complete aggressive treatment, have not yet been well-established in PDAC. The aim of this study was to elucidate the relationship between the combined index using psoas muscle mass index (PMI) values and controlling nutritional status (CONUT) score and prognosis. We included 101 patients diagnosed with PDAC who underwent radical pancreatectomy with regional lymphadenectomy. The cut-off value was set at the first quartile (male, 6.3 cm2/m2; female 4.4 cm2/m2), and patients were classified into high PMI and low PMI groups. A CONUT score of 0 to 1 was classified as the normal nutritional status group, and 2 or more points as the malnutritional status group. Patients were further divided into three groups: high PMI and normal nutrition (good general condition group), low PMI and low nutrition (poor general condition group), and none of the above (moderate general condition group). We performed a prognostic analysis of overall survival (OS), stratified according to PMI values and CONUT scores. In the poor general condition group, the proportion of elderly people over 70 years of age was significantly higher than that in the other groups (p < 0.001). The poor general condition group had a significantly worse prognosis than the good and moderate general condition groups (p = 0.012 and p = 0.037). The 5-year survival rates were 10.9%, 22.3%, and 36.1% in the poor, moderate, and good general condition groups, respectively. In multivariate analysis, poor general condition, with both low PMI and malnutrition status, was an independent poor prognostic factor for postoperative OS (hazard ratio 2.161, p = 0.031). The combination of PMI and CONUT scores may be useful for predicting the prognosis of patients with PDAC after radical surgery.

Clinical outcomes of minimally invasive (laparoscopic and robotic) versus open extended cholecystectomy: A multicenter propensity score matched study.

This multicenter study aimed to compare the clinical outcomes of minimally invasive extended cholecystectomy (MI-EC) versus open EC (O-EC) for patients with gallbladder cancer (GBC). Patients who underwent EC (cholecystectomy, wedge resection of the liver bed, and regional lymphadenectomy) for GBC between 2010 and 2020 in three centers were included in the study. The clinicopathological data were compared after propensity score matching. Additional subgroup analysis on laparoscopic and robotic EC (L-EC and R-EC) was performed. A total of 377 patients were included: 308 for O-EC and 69 for MI-EC, respectively. The MI-EC group had a longer operative time (188.9 vs. 238.1 min, p < .001) and shorter hospital stay (9.0 vs. 7.2 days, p = .007), although no differences were found in operative blood loss, complication rate and survival outcome. In subgroup analysis, L-EC patients had a longer operative time (264.4 vs. 202.0 min, p = .001), compared to R-EC patients with comparable perioperative and survival outcomes. Although patients with MI-EC had a longer operation time and higher medical costs, the advantages were enhanced recovery with comparable short- and long-term outcomes. The operation time was less for R-EC patients than for L-EC patients, though the high cost still remains. The surgery type for EC can be selected according to the patient's condition, social status and surgeon's preference.

Impact of extra-nodal extension and AJCC lymph node staging in predicting recurrence following lymphadenectomy in patients with melanoma

BackgroundRegional lymphadenectomy (RL) has traditionally been recommended in patients with melanoma found to have clinical lymphadenopathy or a positive sentinel lymph node biopsy (SLNB). Regional control of disease is still a relevant issue for patients, even after undergoing lymphadenectomy. The goal of this study was to identify the clinicopathologic characteristics that predict locoregional recurrence in patients who have undergone either therapeutic lymph node dissection (TLND) or completion lymph node dissection (CLND) following SLNB. MethodsRetrospective review of population-based cohort of patients with melanoma lymph node metastasis from the years 2005–2015. Multivariate, proportional hazards regression analysis was performed to determine factors predicting nodal recurrence. Results586 patients underwent a RL, with a median follow up of 35 months. Overall, in-basin recurrence rates in the axilla, groin, and head/neck were 7.7 ​%, 8.7 ​% and 9.2 ​%, respectively. Higher unadjusted recurrence rates occurred following CLND than TLND of the groin (12.8 ​% vs 4.5 ​%) and neck (10.0 ​% vs 4.7 ​%) but not the axilla (7.5 ​% vs 8.0 ​%). Upon multivariate analysis, ENE (HR 2.77; p=<0.0001) and the AJCC lymph node stage (N3 vs N1) (HR 2.51; p ​= ​0.025) were predictive of regional recurrence. ConclusionThe AJCC nodal stage and the presence of extranodal extension were the only variables impacting regional recurrence following regional lymphadenectomy for melanoma. When considering regional disease control, they should be factored into treatment decisions, and surveillance strategies.

When Should Lymphadenectomy Be Performed in Non-Metastatic Pancreatic Neuroendocrine Tumors? A Population-Based Analysis of the German Clinical Cancer Registry Group.

Patient selection for lymphadenectomy remains a controversial aspect in the treatment of pancreatic neuroendocrine tumors (pNETs), given the growing importance of parenchyma-sparing resections and minimally invasive procedures. This population-based analysis was derived from the German Cancer Registry Group during the period from 2000 to 2021. Patients with upfront resected non-functional non-metastatic pNETs were included. Out of 5520 patients with pNET, 1006 patients met the inclusion criteria. Fifty-three percent of the patients were male. The median age was 64 ± 17 years. G1, G2, and G3 pNETs were found in 57%, 37%, and 7% of the patients, respectively. Lymph node metastasis (LNM) was present in 253 (24%) of all patients. LNM was an independent prognostic factor (HR 1.79, CI 95% 1.21-2.64, p = 0.001) for disease-free survival (DFS). The 3-, 5-, and 10-year disease-free survival in nodal negative tumors compared to nodal positive was 82% vs. 53%, 75% vs. 38%, and 48% vs. 16%. LNM was present in 5% of T1 tumors, 25% of T2 tumors, and 49% of T3-T4 tumors. In T1 tumors, G1 was the most predominant tumor grade (80%). However, in T2 tumors, G2 and G3 represented 44% and 5% of all tumors. LNM was associated with tumors located in the pancreatic head (p < 0.001), positive resection margin (p < 0.001), tumors larger than 2 cm (p < 0.001), and higher tumor grade (p < 0.001). The multivariable analysis showed that tumor size, tumor grade, and location were independent prognostic factors associated with LNM that could potentially be used to predict LNM preoperatively. LNM is an independent negative prognostic factor for DFS in pNETs. Due to the low incidence of LNM in T1 tumors (5%), parenchyma-sparing surgery seems oncologically adequate in small G1 pNETs, while regional lymphadenectomy should be recommended in T2 or G2/G3 pNETs.

Adult colocolic intussusception originating in a colonic GIST.

We report the case of an 86-year-old male who was admitted for intestinal subocclusion, in whom an abdominal computed tomography (CT) scan and colonoscopy revealed a colocolonic intussusception with an underlying and heterogeneous mass, failing to rule out a neoformative lesion. A left hemicolectomy procedure was carried out with regional lymphadenectomy (because of the potential neoplastic origin) through laparoscopy, and the patient had a favourable postoperative course. Pathology described 45cm of an intestinal segment, with intussusception and with a 12x7x6 cm ulcerated polypoid lesion. Lesion was revealed as high grade GIST, pathological state of pT4, N0 and free margins. The patient was treated with adjuvant Imatinib. The presentation of a colonic GIST as a colocolic intussusception causing intestinal subocclusion is an extraordinary case, and in our patient, early diagnosis with abdominal CT and free margin surgery were key for successful management.

Correlation between computed tomography and histological evaluation of nodal metastasis in dogs with mast cell tumours.

Early diagnosis of nodal metastasis has been shown to impact prognosis for dogs with mast cell tumours (MCT). The objective of this retrospective study was to determine the correlation between computed tomographic characteristics of lymph nodes and histologic nodal metastasis using the HN classification system, in dogs with cutaneous or subcutaneous MCT and regional lymph node(s) removal. Dogs that had removal of MCT and regional lymphadenectomy within 31 days of the initial staging computed tomography (CT) were enrolled. Subjective lymph node characteristics used included margination, loss of fat at hilus, shape of margin, perinodal fat pattern, increase in number of nodes, and pre- and post-contrast heterogeneity. Enhancement, heterogeneity, and short-long axis ratio were calculated. Seventy-one lymph nodes from 37 dogs were included. Generalised linear mixed model of assessment of lymph node was performed twice, with binary outcome [non-metastatic (HN0/1) versus metastatic (HN2/3)] and 4-point scales (HN0-HN3). After blind assessment of 7 characteristics described above, a final subjective interpretation of each lymph node as non-metastatic or metastatic was assigned. A significant correlation was found between final interpretation and prediction of metastasis. Higher HN classification was also significantly correlated with the increased number of nodes and pre- and post-contrast heterogeneity. No correlation was found in short-long axis ratio, calculated heterogeneity, or degree of enhancement. Sensitivity of CT was 35.7%, specificity was 96.6%, and accuracy was 60.5% for nodal metastasis. CT alone cannot be recommended for assessment of metastasis. The use of multiple computed tomographic characteristics may increase accuracy of nodal metastasis detection.

Exploring the Potential Role of Upper Abdominal Peritonectomy in Advanced Ovarian Cancer Cytoreductive Surgery Using Explainable Artificial Intelligence.

The Surgical Complexity Score (SCS) has been widely used to describe the surgical effort during advanced stage epithelial ovarian cancer (EOC) cytoreduction. Referring to a variety of multi-visceral resections, it best combines the numbers with the complexity of the sub-procedures. Nevertheless, not all potential surgical procedures are described by this score. Lately, the European Society for Gynaecological Oncology (ESGO) has established standard outcome quality indicators pertinent to achieving complete cytoreduction (CC0). There is a need to define what weight all these surgical sub-procedures comprising CC0 would be given. Prospectively collected data from 560 surgically cytoreduced advanced stage EOC patients were analysed at a UK tertiary referral centre.We adapted the structured ESGO ovarian cancer report template. We employed the eXtreme Gradient Boosting (XGBoost) algorithm to model a long list of surgical sub-procedures. We applied the Shapley Additive explanations (SHAP) framework to provide global (cohort) explainability. We used Cox regression for survival analysis and constructed Kaplan-Meier curves. The XGBoost model predicted CC0 with an acceptable accuracy (area under curve [AUC] = 0.70; 95% confidence interval [CI] = 0.63-0.76). Visual quantification of the feature importance for the prediction of CC0 identified upper abdominal peritonectomy (UAP) as the most important feature, followed by regional lymphadenectomies. The UAP best correlated with bladder peritonectomy and diaphragmatic stripping (Pearson's correlations > 0.5). Clear inflection points were shown by pelvic and para-aortic lymph node dissection and ileocecal resection/right hemicolectomy, which increased the probability for CC0. When UAP was solely added to a composite model comprising of engineered features, it substantially enhanced its predictive value (AUC = 0.80, CI = 0.75-0.84). The UAP was predictive of poorer progression-free survival (HR = 1.76, CI 1.14-2.70, P: 0.01) but not overall survival (HR = 1.06, CI 0.56-1.99, P: 0.86). The SCS did not have significant survival impact. Machine Learning allows for operational feature selection by weighting the relative importance of those surgical sub-procedures that appear to be more predictive of CC0. Our study identifies UAP as the most important procedural predictor of CC0 in surgically cytoreduced advanced-stage EOC women. The classification model presented here can potentially be trained with a larger number of samples to generate a robust digital surgical reference in high output tertiary centres. The upper abdominal quadrants should be thoroughly inspected to ensure that CC0 is achievable.

Extent of regional lymphadenectomy and number-based nodal classification for non-ampullary duodenal adenocarcinoma

BackgroundThis study aimed to evaluate the adequate extent of regional lymphadenectomy according to tumor location and the impact of number-based nodal classification on survival in patients with non-ampullary duodenal adenocarcinoma (NADAC). MethodsA total of 85 patients with NADAC who underwent surgery were enrolled. The frequency of metastasis was calculated for each node group in the respective tumor locations for 63 patients who underwent lymphadenectomy for pT2-pT4 tumor. ResultsThe frequency of metastasis in the pancreaticoduodenal (nos. 13 and 17) and superior mesenteric artery (no. 14) nodes was high (16.7 %–52.3 %) regardless of tumor location. Metastasis in the perigastric (nos. 3 and 4d) and right celiac artery (no. 9) nodes was not uncommon (14.3 %–22.2 %) for tumors in the first portion. The frequency of metastasis in the pyloric (nos. 5 and 6) and the other peripancreaticoduodenal (nos. 8 and 12) nodes varied depending on tumor location but could not be ignored for staging. When these nodes were classified as regional nodes, the 5-year survival in patients with pN0, pN1 (1–2 positive nodes), and pN2 (≥3 positive nodes) were 82.9 %, 51.7 %, and 19.2 %, respectively (p < 0.001). pN classification independently predicted survival (pN1, p = 0.022; pN2, p < 0.001). ConclusionsNos. 5, 6, 8, 12, 13, 14, and 17 nodes in all advanced NADAC and nos. 3, 4d, and 9 nodes in advanced NADAC in the first portion should be considered as regional nodes for accurate staging. The number-based nodal classification allows good patients’ prognostic stratification.

203. SURVIVAL IMPACT OF THORACIC DUCT RESECTION IN PATHOLOGICAL RESPONDERS AFTER TRIPLET CHEMOTHERAPY: EXPLORATORY ANALYSIS FROM MULTICENTER PHASE III TRIAL JCOG1109

Abstract Purpose JCOG1109 was a three-arm randomized phase III trial to confirm the survival advantage of docetaxel plus cisplatin plus 5-fluorouracil (DCF) and cisplatin plus 5-fluorouracil (CF) combined with radiotherapy (CF-RT) over CF as preoperative treatment for locally advanced esophageal squamous cell carcinoma. The purpose of this study was to evaluate the survival impact of thoracic duct (TD) resection, and its association with preoperative treatment and pathological response in patients who were enrolled to JCOG1109. Materials and Methods: Patients with potentially resectable advanced thoracic esophageal cancer were randomly assigned to three preoperative therapies and followed by open or thoracoscopic esophagectomy with regional lymphadenectomy. Clinicopathological factors, surgical results which include the status of TD resection, and survival were compared among groups. Furthermore, the survival impact of TD resection was evaluated in the subgroup based on pathological response and preoperative therapy. Results Between December 2012 and July 2018, 601 patients were randomized (CF/DCF/CF-RT; 199/202/200). Of 589 eligible patients to JCOG1109, 541 patients underwent esophagectomy (CF/DCF/CF-RT, 183/181/177). The patients with TD resection showed significantly worse PFS in pathological non-responders, whereas no significant difference in pathological responders. When survival impact of TD resection was evaluated in the subgroup analysis using preoperative treatment and pathological response, patients with TD resection showed significantly better PFS and OS in those who received DCF and achieved pathological response. Conclusion Intensive local control with TD resection in esophagectomy might contribute to improve survival in pathological responders after preoperative DCF therapy.