Refining gastric cancer staging: examining the interplay between number and anatomical location of metastatic lymph nodes - a retrospective multi-institutional study.

BACKGROUND: The current gastric cancer staging system relies on the number of metastatic lymph nodes (MLNs) for nodal stage determination. However, incorporating additional information such as topographic status may help address uncertainties. This study evaluated the appropriateness of the current staging system and relative significance of MLNs based on their anatomical location. METHODS: Patients who underwent curative gastrectomy for gastric cancer between 2000 and 2019 at six Catholic Medical Center-affiliated hospitals were included. Lymph node-positive patients were classified into the perigastric (stations 1-6, group P) or extragastric (stations 7-12) groups. The extragastric group was further subdivided into the near-extragastric (stations 7-9, group NE) and far-extragastric (stations 10-12, group FE) groups. RESULTS: We analyzed the data of 3,591 patients with positive lymph node metastases. No significant survival differences were found between group P and the extragastric group in each N stage. However, in N1 and N2, group FE showed significantly worse survival than the other groups (p = 0.013 for N1, p < 0.001 for N2), but not in N3. In the subgroup analysis, group FE had a significantly lower overall survival in N2, regardless of the cancer location. CONCLUSIONS: Our large-scale multi-institutional big data analysis confirmed the superiority of the current numerical nodal staging system for gastric cancer. Nonetheless, in N1 and N2 in which there is an upper limit on metastatic nodes, attention should be paid to the potential significance of topographic information for specific nodal stations.

Worse Survival of Patients With T1 Stage II Gastric Cancer Following Radical Gastrectomy.

PURPOSE: Lymph node (LN) metastasis is a crucial factor in the prognosis of patients with gastric cancer (GC) and is known to occur more frequently in cases with an advanced T stage. This study aimed to analyze the survival data of patients with advanced LN metastasis in T1 GC. MATERIALS AND METHODS: From January 2008 to June 2018, 677 patients with pathological stage II GC who underwent radical gastrectomy were divided into an early GC group (EG: T1N2 and T1N3a, n=103) and an advanced GC (AGC) group (AG: T2N1, T2N2, T3N0, T3N1, and T4aN0, n=574). Short- and long-term survival rates were compared between the 2 groups. RESULTS: A total of 80.6% (n=83) of the patients in the EG group and 52.8% (n=303) in the AG group had stage IIA AGC. The extent of LN dissection, number of retrieved LNs, and short-term morbidity and mortality rates did not differ between the 2 groups. The 5-year relapse-free survival (RFS) of all patients was 87.8% and the overall survival was 84.0%. RFS was lower in the EG group than in the AG group (82.2% vs. 88.7%, P=0.047). This difference was more pronounced among patients with stage IIA (82.4% vs. 92.9%, P=0.003). CONCLUSIONS: T1 GC with multiple LN metastases seems to have a worse prognosis compared to tumors with higher T-stages at the same level. Adjuvant chemotherapy is highly recommended for these patients, and future staging systems may require upstaging T1N2-stage tumors.

Advances in methylation analysis of liquid biopsy in early cancer detection of colorectal and lung cancer.

Methylation patterns in cell-free DNA (cfDNA) have emerged as a promising genomic feature for detecting the presence of cancer and determining its origin. The purpose of this study was to evaluate the diagnostic performance of methylation-sensitive restriction enzyme digestion followed by sequencing (MRE-Seq) using cfDNA, and to investigate the cancer signal origin (CSO) of the cancer using a deep neural network (DNN) analyses for liquid biopsy of colorectal and lung cancer. We developed a selective MRE-Seq method with DNN learning-based prediction model using demethylated-sequence-depth patterns from 63,266 CpG sites using SacII enzyme digestion. A total of 191 patients with stage I-IV cancers (95 lung cancers and 96 colorectal cancers) and 126 noncancer participants were enrolled in this study. Our study showed an area under the receiver operating characteristic curve (AUC) of 0.978 with a sensitivity of 78.1% for colorectal cancer, and an AUC of 0.956 with a sensitivity of 66.3% for lung cancer, both at a specificity of 99.2%. For colorectal cancer, sensitivities for stages I-IV ranged from 76.2 to 83.3% while for lung cancer, sensitivities for stages I-IV ranged from 44.4 to 78.9%, both again at a specificity of 99.2%. The CSO model's true-positive rates were 94.4% and 89.9% for colorectal and lung cancers, respectively. The MRE-Seq was found to be a useful method for detecting global hypomethylation patterns in liquid biopsy samples and accurately diagnosing colorectal and lung cancers, as well as determining CSO of the cancer using DNN analysis.Trial registration: This trial was registered at ClinicalTrials.gov (registration number: NCT04253509) for lung cancer on 5 February 2020, https://clinicaltrials.gov/ct2/show/NCT04253509 . Colorectal cancer samples were retrospectively registered at CRIS (Clinical Research Information Service, registration number: KCT0008037) on 23 December 2022, https://cris.nih.go.kr , https://who.init/ictrp . Healthy control samples were retrospectively registered.

A Nomogram for Predicting Extraperigastric Lymph Node Metastasis in Patients With Early Gastric Cancer.

BACKGROUND: There are no clear guidelines to determine whether to perform D1 or D1+ lymph node dissection in early gastric cancer (EGC). This study aimed to develop a nomogram for estimating the risk of extraperigastric lymph node metastasis (LNM). MATERIALS AND METHODS: Between 2009 and 2019, a total of 4,482 patients with pathologically confirmed T1 disease at 6 affiliated hospitals were included in this study. The basic clinicopathological characteristics of the positive and negative extraperigastric LNM groups were compared. The possible risk factors were evaluated using univariate and multivariate analyses. Based on these results, a risk prediction model was developed. A nomogram predicting extraperigastric LNM was used for internal validation. RESULTS: Multivariate analyses showed that tumor size (cut-off value 3.0 cm, odds ratio [OR]=1.886, P=0.030), tumor depth (OR=1.853 for tumors with sm2 and sm3 invasion, P=0.010), cross-sectional location (OR=0.490 for tumors located on the greater curvature, P=0.0303), differentiation (OR=0.584 for differentiated tumors, P=0.0070), and lymphovascular invasion (OR=11.125, P<0.001) are possible risk factors for extraperigastric LNM. An equation for estimating the risk of extraperigastric LNM was derived from these risk factors. The equation was internally validated by comparing the actual metastatic rate with the predicted rate, which showed good agreement. CONCLUSIONS: A nomogram for estimating the risk of extraperigastric LNM in EGC was successfully developed. Although there are some limitations to applying this model because it was developed based on pathological data, it can be optimally adapted for patients who require curative gastrectomy after endoscopic submucosal dissection.

Is Total Omentectomy Mandatory in T3 and T4a Gastric Cancer for Laparoscopic Distal Gastrectomy?

BACKGROUND: Despite the lack of strong evidence, total omentectomy (TO) remains the recommended procedure for gastric cancer (GC) for T3 or deeper tumors. Partial omentectomy (PO) has recently become a preferred procedure owing to its simplicity during laparoscopic distal gastrectomy (LDG); however, the oncological role of PO needs to be elucidated. METHODS: Overall, 341 patients with T3 or T4a GC who had undergone LDG between 2009 and 2016 were divided into TO (n = 167) and PO (n = 174) groups. Propensity matching was performed with respect to covariance age, sex, T and N stage, tumor size, and degree of tumor differentiation. Clinicopathological characteristics and long-term follow-up data were analyzed for both groups. RESULTS: After successful propensity matching, both groups included 107 patients. In a matched cohort, no significant difference in clinicopathologic features and short-term surgical outcomes was observed between the two groups. Furthermore, no significant difference in relapse-free survival (RFS; p = 0.201) and peritoneal seeding-free survival (PSFS; p = 0.094) was observed. However, tumor recurrence as peritoneal metastasis occurred in 5 (4.7%) patients in the PO group and 13 (12.1%) patients in the TO group. In Cox proportional hazards analysis, omentectomy was not identified as a significant factor for RFS, PSFS, and overall survival; however, advanced N and T4a stage were considered significant factors for RFS and PSFS, respectively. CONCLUSIONS: PO may be adopted during the LDG of T3 or T4a GC without definite gross serosal exposure. More large-scale evidence or prospective study is recommended.

Experience of serious intestinal hemorrhage and perforation in small bowel lymphoma: a case report.

There have been several reports of complications of small bowel lymphoma, such as bleeding, obstruction, and perforation, often require emergency surgery. It is hardly showed complications of bleeding and wound dehiscence for diffuse large B cell lymphoma with distal ileum involvement, which needed urgent surgery and medical management. A 65-year-old man with diffuse large B-cell lymphoma with distal ileum involvement experienced both intestinal bleeding and perforation during the course of treatment. As the patient was diagnosed with stage III disease, resection before chemotherapy was not considered due to the resulting delay in chemotherapy, which necessitated sufficient tissue healing. Chemotherapy is important when treating small bowel lymphoma, complications such as bleeding and perforation should always be considered for the treatment of small bowel lymphoma, and surgery is necessary in this situation. After surgery of the small bowel, subsequent chemotherapy could cause wound dehiscence and perforation; therefore, adequate recovery time should be given before chemotherapy.

The utility of high-mobility group A2 overexpression for predicting the prognosis of gastric cancer patients and its contribution to poor prognosis via chemoresistance and the propensity for the occurrence of carcinomatosis peritonei.

BACKGROUND: The aim of this study was to elucidate the correlation of high-mobility group protein A2 overexpression with gastric cancer prognosis and compare its prognostic power with that of pre-existing markers. METHODS: Malignant tissues from 396 patients with gastric cancer who underwent gastrectomy from 2008 to 2012 were examined. High-mobility group protein A2 expression was assessed by immunohistochemistry and the sensitivity and specificity for predicting disease progression and overall survival of high-mobility group protein A2 and the prognostic biomarkers p53, Ki-67, human epidermal growth factor receptor 2, cyclooxygenase-2, and epidermal growth factor receptor were compared. RESULTS: A total of 95 samples (24.1%) showed high-mobility group protein A2 overexpression, which was related to advanced stage, undifferentiated histology, and lymphatic and perineural invasion. Additionally, high-mobility group protein A2 overexpression was an independent prognostic factor in multivariate analysis for disease progression and overall survival. Based on Kaplan-Meier survival analysis disease progression and overall survival, the high-mobility group protein A2-overexpressing patients showed worse survival. The recurrence pattern of peritoneal dissemination was more frequently observed in high-mobility group protein A2-positive group. Moreover, chemoresistance was more frequently observed in the high-mobility group protein A2-positive group. High-mobility group protein A2 exhibited a better ability for predicting disease progression and overall survival than other markers, and the prognostic power was enhanced when high-mobility group protein A2 was used with these markers. CONCLUSION: High-mobility group protein A2 overexpression is associated with chemoresistance and a propensity for carcinomatosis peritonei after surgery in patients with gastric cancer. The power to predict the prognosis of patients with gastric cancer can be enhanced with the use of preexisting biomarkers and high-mobility group protein A2.

Long-Term Outcomes of Laparoscopic versus Open Total Gastrectomy for Advanced Gastric Cancer: A Propensity Score-Matched Analysis.

BACKGROUND: Laparoscopic total gastrectomy (LTG) for advanced gastric cancer (AGC) is a technically and oncologically challenging procedure for surgeons. OBJECTIVES: The aim of this study was to compare the technical safety and long-term oncological feasibility between LTG and open total gastrectomy (OTG) for patients with AGC using a propensity score (PS)-matched analysis. METHODS: Between 2004 and 2014, 185 patients (OTG: 127, LTG: 58) underwent curative total gastrectomy for AGC. PS matching was performed using the patients' clinicopathological factors, and comparisons were made based on surgical outcomes and long-term survival rates. RESULTS: After PS matching, 102 patients (51 patients in each group) were enrolled. The total numbers of retrieved lymph nodes were similar in both groups. The numbers of retrieved lymph nodes around the splenic hilum were similar in both groups. A longer operation time was required for the LTG group than for the OTG group, but less intraoperative bleeding was observed in the LTG group. The overall morbidity and mortality rates of both groups were similar. Between the 2 groups, there was no difference in the 5-year overall survival rate or disease-free survival rate. CONCLUSIONS: For treating proximal AGC, LTG may be a technically and an oncologically safe and feasible method.

Negative Impact of Endoscopic Submucosal Dissection on Short-Term Surgical Outcomes of Subsequent Laparoscopic Distal Gastrectomy for Gastric Cancer.

BACKGROUND: Endoscopic submucosal dissection (ESD) for gastric cancer produces an artificial ulcer, and negative effects on the surgical outcomes of additional gastrectomy after ESD are anticipated. The aim of this study is to analyze the effect of ESD on subsequent laparoscopic radical gastrectomy procedures and to compare the surgical results of post-ESD patients with the control group using propensity score (PS) methods. PATIENTS AND METHODS: From 2013 to 2018, 1446 patients underwent totally laparoscopic distal gastrectomy in our center. Among these patients, the clinicopathological factors and short-term surgical outcomes of 107 patients who underwent ESD before surgery (the ESD group) were evaluated. A 1:4 PS matching and inverse probability weighting method was utilized to compare the short-term surgical outcomes of the ESD group with those of a matched control group. RESULTS: A longer operation time was required for the patients who underwent gastrectomy earlier than 24 days after ESD than for the patients who did not. Patients whose ulcer size, due to previous ESD, exceeded 4.6 cm required longer operation times and exhibited more intraoperative blood loss than patients whose ulcer size was small. In the PS matching analysis, patients who underwent distal gastrectomy within 24 days after ESD showed more frequent postoperative morbidity than non-ESD patients. CONCLUSIONS: ESD after laparoscopic distal gastrectomy is largely safe in terms of short-term surgical outcomes, but a short interval between the two procedures and a large ESD scar can make subsequent operation difficult.

Retroperitoneal abscess with pylephlebitis caused by lumbar acupuncture: a case report.

BACKGROUND: Retroperitoneal abscess (RA) is an unusual life-threatening disease that has insidious and occult presentations. Although the incidence of this disease is low, diagnosis and treatment are challenging due to its nonspecific presentation and the complex anatomy of the retroperitoneal space. Recently, we experienced one case of a RA with extensive thrombophlebitis of the portal venous system. CASE PRESENTATION: An 80-year-old male presented to the emergency room with symptoms and signs of septic shock; however, the decision making for diagnosis and treatment was difficult, as no clinical and radiological evidence supported key findings regarding the origin of sepsis. Although this patient eventually recovered after surgical drainage, we suggested that more straightforward diagnostic and treatment procedures were required in this patient to avoid possible critical complications. Through a retrospective review of operative findings, patient history, and microbiology, we found that the RA in this patient was caused by lumbar acupuncture, which is usually performed for the management of chronic back pain with long needles. CONCLUSION: Early surgical intervention should be considered for RA whenever the patient does not respond to broad-spectrum antibiotic treatment. Acupuncture is a possible cause of otherwise unexplained soft tissue infections, such as RA, especially in Asian countries.

Anatomic variations in the left gastric vein and their clinical significance during laparoscopic gastrectomy.

BACKGROUND: Surgeons normally encounter the left gastric vein (LGV) during laparoscopic gastrectomy (LG) for gastric cancer, and the various anatomic variants of this vessel make the procedure difficult. The objective of this study was to classify anatomic variants of the LGV in the laparoscopic operation field and clarify their clinical significance during LG. METHODS: In total, 405 patients who underwent LG in 2013-2017 for gastric cancer were enrolled in the study. LGV drainage was classified into six types by the anatomic relation of the LGV to the arteries of the celiac axis: Type Ia [LGV runs anteriorly to the common hepatic artery (CHA)], Type Ip (LGV runs posteriorly to CHA), Type II (LGV runs anteriorly to the left gastric artery), Type IIIa [LGV runs anteriorly to the splenic artery (SA)], Type IIIp (LGV runs posteriorly to SA), and Type IV (LGV runs cranially into the proximal portal vein or liver parenchyma). If the LGV was injured during the operation, the patient was included as a member of the injury group (IG). RESULTS: Most patients (n = 391, 96.5%) had a single LGV, whereas 14 (3.5%) patients had double LGVs. Type Ip was the most common of the six drainage types (n = 195, 48.1%). The number of patients in the IG was 49 (13.0%). Types I and III were relatively easily injured when compared with type II (p = 0.025). Patients in the IG had longer operation times, more blood loss, and more lymph node metastases than the non-IG patients. CONCLUSIONS: In most patients, the LGV drains posteriorly to the CHA or anteriorly to the LGA. Gastric surgeons should take great care not to injure the LGV during LG when it is not present on the anterior side of the celiac axis.

Safety of Laparoscopic Radical Gastrectomy in Gastric Cancer Patients with End-Stage Renal Disease.

PURPOSE: The surgical outcomes of end-stage renal disease (ESRD) patients undergoing radical gastrectomy for gastric cancer were inferior compared with those of non-ESRD patients. This study aimed to evaluate the short- and long-term surgical outcomes of ESRD patients undergoing laparoscopic gastrectomy (LG) and open gastrectomy (OG) for gastric cancer. MATERIALS AND METHODS: Between 2004 and 2014, 38 patients (OG: 21 patients, LG: 17 patients) with ESRD underwent gastrectomy for gastric cancer. Comparisons were made based on the clinicopathological characteristics, surgical outcomes, and long-term survival rates. RESULTS: No significant differences were noted in the clinicopathological characteristics of either group. LG patients had lower estimated blood loss volumes than OG patients (LG vs. OG: 94 vs. 275 mL, P=0.005). The operation time and postoperative hospital stay were similar in both the groups. The postoperative morbidity for LG and OG patients was 41.1% and 33.3%, respectively (P=0.873). No significant difference was observed in the long-term overall survival rates between the 2 groups (5-year overall survival, LG vs. OG: 82.4% vs. 64.7%, P=0.947). CONCLUSIONS: In ESRD patients, LG yielded non-inferior short- and long-term surgical outcomes compared to OG. Laparoscopic procedures might be safely adopted for ESRD patients who can benefit from the advantages of minimally invasive surgery.

Feasibility and Safety of Totally Laparoscopic Radical Gastrectomy for Advanced Gastric Cancer: Comparison with Early Gastric Cancer.

PURPOSE: Totally laparoscopic gastrectomy (TLG) for advanced gastric cancer (AGC) is a technically and oncologically challenging procedure for surgeons. This study aimed to compare the oncologic feasibility and technical safety of TLG for AGC versus early gastric cancer (EGC). MATERIALS AND METHODS: Between 2011 and 2016, 535 patients (EGC, 375; AGC, 160) underwent curative TLG for gastric cancer. Clinicopathologic characteristics and surgical outcomes of both patient groups were analyzed and compared. RESULTS: Patients with AGC required a longer operation time and experienced more intraoperative blood loss than those with EGC did. However, patients from both the AGC and EGC groups demonstrated similar short-term surgical outcomes such as postoperative morbidity (14.4% vs. 13.3%, P=0.626), mortality (0% vs. 0.5%, P=0.879), time-to-first oral intake (2.7 days for both groups, P=0.830), and postoperative hospital stay (10.2 days vs. 10.1 days, P=0.886). D2 lymph node dissection could be achieved in the AGC group (95%), with an adequate number of lymph nodes being dissected (36.0±14.9). In the AGC group, the 3-year overall and disease-free survival rates were 80.5% and 73.7%, respectively. CONCLUSIONS: TLG is as safe and effective for AGC as it is for EGC.

Small cell carcinoma of the gallbladder: a case report.

Small cell carcinoma (SCC) of the gallbladder is an extremely rare tumor. Despite aggressive and varied treatments, its prognosis is poor. A 70-year-old woman undergoing treatment for pneumonia was detected with a gallbladder mass. Radical cholecystectomy was performed and the pathology revealed small cell carcinoma. There were metastases in 2 lymph nodes, scoring T2N1M0, stage IIIB (AJCC 7th). The patient has survived thus far, with subsequent chemotherapy. SCC of the gallbladder has an extremely low incidence and poor prognosis. In some cases, radical surgery with chemotherapy or radiation therapy could increase survival rate of patients.

Comparative study comparing endoscopic thyroidectomy using the axillary approach and open thyroidectomy for papillary thyroid microcarcinoma.

BACKGROUND: Endoscopic thyroidectomy has been applied prudently to malignant thyroid tumors. The purpose of our study was to compare the surgical outcomes of endoscopic thyroidectomy (ET) and conventional open thyroidectomy (COT) for micropapillary thyroid carcinoma. METHODS: From October 2002 to December 2008, 78 patients underwent unilateral lobectomy and isthmectomy with central lymph node dissection for papillary thyroid microcarcinoma. Of these, 37 patients underwent ET and 41 patients COT. Surgical outcomes, including operation time, number of retrieved lymph nodes, postoperative complication rate and patients' satisfaction with the cosmetic results, were analyzed. RESULTS: The mean age of the patients was 42.3 ± 7.6 years in the ET group and 49.0 ± 10.8 years in the OT group (P = 0.003). The operation time was shorter in the COT group (112.3 ± 14 min) than in the ET group (138.4 ± 36.9 min, P< 0.01). However, there were no significant differences in tumor size (0.5 ± 0.231 vs. 0.41 ± 0.264 cm, P = 0.116), number of retrieved lymph nodes (3.63 ± 2.1 vs. 3.82 ± 3.28, P = 0.78) or postoperative hospital stay (3.35 ± 0.94 vs. 3.17 ± 1.16 days, P = 0.457). Patients in the ET group experienced more pain than those in the COT group at 1 and 7 days after the operation as evaluated by a visual analog scale (P = 0.037, 0.026). Cosmetically, patients in the ET group were very satisfied with the operative procedure according to the questionnaire we used (1.43 ± 0.55 vs. 3.21 ± 0.72, P< 0.001). The mean follow-up period was 54.3 months in the ET group and 47.4 months in the COT group, and each group exhibited one case of tumor recurrence detected at the other thyroid lobe within 2 years. CONCLUSIONS: Large series of prospective studies and long-term follow-up are needed, but the results of ET using the axillary approach for micropapillary thyroid carcinoma were not inferiortothose using COT, and it might be a safe and feasible procedure with good cosmetic results.