Explainable machine learning using perioperative serial laboratory results to predict postoperative mortality in patients with peritonitis-induced sepsis.

Purpose: Sepsis is one of the most common causes of death after surgery. Several conventional scoring systems have been developed to predict the outcome of sepsis; however, their predictive power is insufficient. The present study applies explainable machine-learning algorithms to improve the accuracy of predicting postoperative mortality in patients with sepsis caused by peritonitis. Methods: We performed a retrospective analysis of data from demographic, clinical, and laboratory analyses, including the delta neutrophil index (DNI), WBC and neutrophil counts, and CRP level. Laboratory data were measured before surgery, 12-36 hours after surgery, and 60-84 hours after surgery. The primary study output was the probability of mortality. The areas under the receiver operating characteristic curves (AUCs) of several machine-learning algorithms using the Sequential Organ Failure Assessment (SOFA) and Simplified Acute Physiology Score (SAPS) 3 models were compared. 'SHapley Additive exPlanations' values were used to indicate the direction of the relationship between a variable and mortality. Results: The CatBoost model yielded the highest AUC (0.933) for mortality compared to SAPS3 and SOFA (0.860 and 0.867, respectively). Increased DNI on day 3, septic shock, use of norepinephrine therapy, and increased international normalized ratio on day 3 had the greatest impact on the model's prediction of mortality. Conclusion: Machine-learning algorithms increase the accuracy of predicting postoperative mortality in patients with sepsis caused by peritonitis.

Is it worth applying self-irrigation after third molar extraction? A randomised controlled trial.

In this study, we aimed to examine the effectiveness of self-irrigation following the extraction of mandibular third molars. A randomised controlled clinical trial was conducted with 155 patients who had undergone extraction of a mandibular third molar. The irrigation group was instructed to self-irrigate the extraction socket with tap water using a syringe three times a day, starting seven days after the tooth extraction. The incidence of complications and mouth opening, halitosis, plaque/gingival index, and oral health-related quality of life (OHRQoL) were measured. The irrigation group showed a lower incidence of complications than the non-irrigation group. The halitosis, plaque, and gingival scores were lower by mean (SD) 19.66 (5.19), 0.58 (0.06), and 0.62 (0.08), respectively, in the irrigation group than in the non-irrigation group (p = 0.0001). A greater amount of food packing was associated with higher halitosis, plaque, and gingival scores and poorer OHRQoL (p < 0.05). Further, more frequent irrigation was associated with lower halitosis, plaque, and gingival scores and better OHRQoL (p ≤ 0.016). Self-irrigation of the extraction socket using a syringe containing tap water is a very effective method for keeping the extraction socket clean. This technique reduced halitosis, improved plaque and gingival indices, and increased OHRQoL.

Effective Pre-Training Method and Its Compositional Intelligence for Image Captioning.

With the increase in the performance of deep learning models, the model parameter has increased exponentially. An increase in model parameters leads to an increase in computation and training time, i.e., an increase in training cost. To reduce the training cost, we propose Compositional Intelligence (CI). This is a reuse method that combines pre-trained models for different tasks. Since the CI uses a well-trained model, good performance and small training cost can be expected in the target task. We applied the CI to the Image Captioning task. Compared to using a trained feature extractor, the caption generator is usually trained from scratch. On the other hand, we pre-trained the Transformer model as a caption generator and applied CI, i.e., we used a pre-trained feature extractor and a pre-trained caption generator. To compare the training cost of the From Scratch model and the CI model, early stopping was applied during fine-tuning of the image captioning task. On the MS-COCO dataset, the vanilla image captioning model reduced training cost by 13.8% and improved performance by up to 3.2%, and the Object Relation Transformer model reduced training cost by 21.3%.

Delta neutrophil index and symptomatic time are effective factors for predicting perforated appendicitis.

ABSTRACT: Appendicitis is a common intra-abdominal inflammatory disease, and morbidity increases with age when perforation occurs. Because, not all patients require emergency surgery, there have been numerous studies on factors for predicting perforated appendicitis. In this study, we aimed to confirm whether the delta neutrophil index (DNI) and the time from symptom onset to surgery are effective predictors for perforated appendicitis in different age groups.This was a retrospective study conducted on 542 appendicitis patients who underwent surgery at Kangdong Sacred Heart Hospital. The simple group consisted of 431 subjects, and the perforation group consisted of 111 subjects.Multiple logistic regression analyses demonstrated that age, neutrophil percentage, DNI, C-reactive protein (CRP), and symptomatic time were significant predictors of perforation. Analysis of the receiver-operating characteristic curve showed that the DNI was the most reliable predictive value. In the analyses according to age, the perforation rate was higher in the >65-year-age group; these patients also had a higher DNI, CRP, and symptomatic time. In the DNI analysis using receiver operating characteristic (ROC) analysis, the area under the curve was higher in the >65-year-age group than in other age groups. In addition, the cutoff values have been determined and perforation occurred significantly in the group with a DNI value of 2.1 or higher and a symptomatic time of 33 hours or longer.DNI is effective in predicting perforation in patients with appendicitis compared with other inflammatory factors. Furthermore, the simultaneous measurement of symptomatic time and DNI is helpful in predicting perforation and determining whether emergency surgery is necessary.

Primary repair of untreated cleft palate in an elderly patient: a case report.

Untreated adult or elderly cleft lip and palate patients are rarely seen, but studies on delayed primary palatal closure have been performed in the less developed Asian and African countries, where access to medical care is difficult. A 64-year-old woman visited our clinic with untreated cleft palate with a 40×20-mm-wide defect in the medial palate. Two-flap palatoplasty under general anesthesia was performed to close the cleft palate. After 1 month, the result was favorable without any complications including oronasal fistula. Cleft palate primary repair in an elderly patient is rare and has some surgical problems that are associated with a wide range of defects, but good results can be obtained if surgery is performed well with appropriate considerations.

Comparative study of bone regeneration using fibrin sealant with xenograft in rabbit sinus: pilot study.

BACKGROUND: Stability of the grafted bone volume is one of the important factors to the success of alveolar bone grafts. For this, platelet-rich plasma (PRP) or fibrin sealant is mixed with the bone graft material. Bio-Oss® is a protein-free bovine mineral commonly used in bone graft procedures. The grafting particles are commonly combined with a standard fibrin sealant (Tisseel®) to fabricate a plastic implantable product. The purpose of this experiment was to evaluate the efficacy of fibrin sealant (Tisseel®) in bone regeneration performance in a rabbit maxillary sinus model. METHODS: A total of five 3.5 kg weight New Zealand white rabbits were used for the study. After elevating the sinus membrane in both maxillary sinus cavities, Bio-Oss® mixed with normal saline (group 1) was filled into the right side, and Tisseel® mixed Bio-Oss® (group 2) was inserted into the other side. The bone mineral density and bone volume were analyzed with microscopic computed tomography (micro-CT) and histomorphometric 12 weeks after application. RESULTS: Histologically, new bone formation rate was 14.8%, and grafted bone rate was 70.5% in group 1. In group 2, they were 18.5% and 60.4%, respectively. According to micro-CT analysis, bone mineral density (mg/cm3, BMD) was 2.5% larger in group 1. CONCLUSIONS: The findings from this study suggest that, although the difference in the bone formation between group 1 and group 2 appears to be insignificant, group 2 had an advantage in using smaller amount of bone substances to achieve the reliable bone formation.

Lymphatic Invasion Might Be Considered as an Upstaging Factor in N0 and N1 Gastric Cancer.

(Background) The aim of this study was to investigate the prognostic impact of lymphatic invasion in gastric cancer, focusing on survival differences between N stage groups. (Methods) A total of 398 consecutive patients who underwent curative gastrectomy for primary gastric adenocarcinoma from January 2006 to December 2015 were analyzed retrospectively using data from a prospectively collected registry database. We compared various clinicopathological features and survival differences between lymphatic invasion-positive and -negative groups. (Results) Of the 398 patients, 141 (35.4%) showed lymphatic invasion. The lymphatic invasion-positive subgroup had poorer prognosis than the lymphatic invasion-negative subgroup in N0 (five-year survival rate: 87.8% vs. 73.6%, p = 0.048) and N1 (87.2% vs. 50%, p = 0.007) stage patients. The odds ratio (OR) of lymphatic invasion to five-year survival rate was 2.078 (95% confidence interval (CI), 1.103-3.916; p = 0.024). The presence of lymphatic invasion had worse effect on survival than age (OR, 1.807; 95% CI, 1.024-2.242; p = 0.029) or tumor depth (OR, 1.286; 95% CI, 1.078-1.897; p = 0.013) in N0 and N1 stage patients. The overall survival of patients with lymphatic invasion was not different from that of patients at a one-higher N stage without lymphatic invasion at any N stage. (Conclusions) The presence of lymphatic invasion may be the most important independent prognostic factor in N0 and N1 gastric cancer and might be an upstaging factor of N stage at any N stage. Therefore, in addition to the number of metastasized lymph nodes, the presence of lymphatic invasion should be included in N stage determination.

Mandibular reconstruction with a ready-made type and a custom-made type titanium mesh after mandibular resection in patients with oral cancer.

BACKGROUND: After the resection at the mandibular site involving oral cancer, free vascularized fibular graft, a type of vascularized autograft, is often used for the mandibular reconstruction. Titanium mesh (T-mesh) and particulate cancellous bone and marrow (PCBM), however, a type of non-vascularized autograft, can also be used for the reconstruction. With the T-mesh applied even in the chin and angle areas, an aesthetic contour with adequate strength and stable fixation can be achieved, and the pores of the mesh will allow the rapid revascularization of the bone graft site. Especially, this technique does not require microvascular training; as such, the surgery time can be shortened. This advantage allows older patients to undergo the reconstructive surgery. CASE PRESENTATION: Reported in this article are two cases of mandibular reconstruction using the ready-made type and custom-made type T-mesh, respectively, after mandibular resection. We had operated double blind peer-review process. A 79-year-old female patient visited the authors' clinic with gingival swelling and pain on the left mandibular region. After wide excision and segmental mandibulectomy, a pectoralis major myocutaneous flap was used to cover the intraoral defect. Fourteen months postoperatively, reconstruction using a ready-made type T-mesh (Striker-Leibinger, Freibrug, Germany) and iliac PCBM was done to repair the mandible left body defect.Another 62-year-old female patient visited the authors' clinic with pain on the right mandibular region. After wide excision and segmental mandibulectomy on the mandibular squamous cell carcinoma (SCC), reconstruction was done with a reconstruction plate and a right fibula free flap. Sixteen months postoperatively, reconstruction using a custom-made type T-mesh and iliac PCBM was done to repair the mandibular defect after the failure of the fibula free flap. The CAD-CAM T-mesh was made prior to the operation. CONCLUSIONS: In both cases, sufficient new-bone formation was observed in terms of volume and strength. In the CAD-CAM custom-made type T-mesh case, especially, it was much easier to fix screws onto the adjacent mandible, and after the removal of the mesh, the appearance of both patients improved, and the neo-mandibular body showed adequate bony volume for implant or prosthetic restoration.

Who Can Perform Adjuvant Chemotherapy Treatment for Gastric Cancer? A Multicenter Retrospective Overview of the Current Status in Korea.

PURPOSE: To investigate the current status of adjuvant chemotherapy (AC) regimens in Korea and the difference in efficacy of AC administered by surgical and medical oncologists in patients with stage II or III gastric cancers. MATERIALS AND METHODS: We performed a retrospective observational study among 1,049 patients who underwent curative resection and received AC for stage II and III gastric cancers between February 2012 and December 2013 at 29 tertiary referral university hospitals in Korea. To minimize the influence of potential confounders on selection bias, propensity score matching (PSM) was used based on binary logistic regression analysis. The 3-year disease-free survival (DFS) rates were compared between patients who received AC administered by medical oncologists or surgical oncologists. RESULTS: Between February 2012 and December 2013 in Korea, the most commonly prescribed AC by medical oncologists was tegafur/gimeracil/oteracil (S-1, 47.72%), followed by capecitabine with oxaliplatin (XELOX, 16.33%). After performing PSM, surgical oncologists (82.74%) completed AC as planned more often than medical oncologists (75.9%), with statistical significance (P=0.036). No difference in the 3-year DFS rates of stage II (P=0.567) or stage III (P=0.545) gastric cancer was found between the medical and surgical oncologist groups. CONCLUSIONS: S-1 monotherapy and XELOX are a main stay of AC, regardless of whether the prescribing physician is a medical or surgical oncologist. The better compliance with AC by surgical oncologists is a valid reason to advocate that surgical oncologists perform the treatment of AC for stage II or III gastric cancers.

Rhabdomyolysis after the free fibular flap operation for mandibular reconstruction: a case report.

BACKGROUND: Free fibular flap is one of the most useful methods in the hard tissue reconstruction of the maxilla-mandible. Free fibular flap presents some advantages in which the reconstruction of both soft and hard tissues can be done at the same time. It also provides a safe and successful bone graft for the reconstruction, along with a low rate of complications. Despite these advantages and the rarity of a postoperative complication, particularly in oral and maxillofacial surgery procedures, a prolonged operation might exhibit some complications related with rhabdomyolysis. We experienced the rare event of rhabdomyolysis after oral cancer surgery. CASE PRESENTATION: In this article, we report the case of a patient who developed rhabdomyolysis after undergoing free fibular flap surgery. CONCLUSIONS: Despite the advantages of the free fibular flap operation, clinicians must be aware of the risk of complications because there are multiple factors that could result in rhabdomyolysis, such as duration of operation, position of the subject, and pre-existing conditions of diabetes and hypertension. Once the diagnosis of rhabdomyolysis is confirmed, a prompt treatment plan should be made and applied as soon as possible. This will increase the chance of a full recovery for the patient who is exhibiting symptoms of rhabdomyolysis.

Microsatellite Alterations and Protein Expression of 5 Major Tumor Suppressor Genes in Gastric Adenocarcinomas.

PURPOSE: In gastric adenocarcinoma (GC), the major tumor suppressor genes (TSGs) such as p16, PTEN, Rb, E-cadherin, and p53, may play important roles in various regulatory pathways and in tumor suppression. This study evaluated the loss of heterozygosity (LOH) of microsatellite and protein expression of 5 TSGs and the results were examined for their correlation with clinicopathological factors. METHODS: LOH analysis was carried out using polymerase chain reactions with 15 polymorphic microsatellite markers of 5 chromosomes containing TSGs in 100 surgically resected tumors. Protein expression was evaluated by immunohistochemistry (IHC). RESULTS: LOH was detected in 83% of GCs. LOH of 9p21, 10q23, 13q14, 16q22, and 17p13 were detected in 26%, 31%, 24%, 22%, and 35% of cases, respectively. Protein expression of p16, PTEN, Rb, E-cadherin, and p53 were found to be 31%, 39%, 28%, 32%, and 46% of cases. Advanced GCs showed significantly higher rates of 17p13 LOH and p53 expression. 9p21 LOH and E-cadherin IHC were correlated with higher tumor grade. Lymph node metastasis was correlated with the LOH of 9p21, 16q22, and 17p13 and IHC of the Rb and p53. A higher stage was correlated with 10q23 and 17p13 in LOH and p53 for IHC. CONCLUSION: These results suggest that LOH and protein expression of various TSGs are important in carcinogenesis and tumor invasion. Additionally, LOH and IHC may be useful clinical indicators for determining the prognosis of patients with GCs. In particular, the 17p13 LOH and p53 for IHC can be applied as simple evaluations in the clinic.

The delta neutrophil index is a prognostic factor for postoperative mortality in patients with sepsis caused by peritonitis.

INTRODUCTION: The delta neutrophil index (DNI) represents the fraction of circulating immature granulocytes and is a marker of infection and sepsis. Our objective was to evaluate the usefulness of DNI for predicting in-hospital mortality within 30 days after surgery in patients with sepsis caused by peritonitis by means of comparing DNI, white blood cell (WBC) count, neutrophil percentage, and C-reactive protein (CRP) before and after surgery. MATERIALS AND METHODS: We performed a retrospective analysis of demographic, clinical, and laboratory data. DNI, WBC count, neutrophil percentage, and CRP were measured before surgery, and at 12-36 h (day 1) and 60-84 h (day 3) after surgery. RESULTS: There were 116 (73.7%) survivors and 44 (26.3%) non-survivors. The rates of septic shock, norepinephrine administration, renal replacement, mechanical ventilator therapy, and reoperation, the Simplified Acute Physiology Score-3 (SAPS3), and the Sepsis-related Organ Failure Assessment (SOFA) score were greater in non-survivors. DNI on day 3 was better than the other laboratory variables for predicting mortality. DNI was correlated with the SAPS3 (r = .46, p = .00) and SOFA score (r = .45, p = .00). The optimal cut-off DNI for predicting mortality was 7.8% (sensitivity: 77.3%; specificity: 95.9%). In receiver-operating characteristic curve analysis, DNI on day 3 was the best indicator of mortality (area under the curve: .880; 95% confidence interval: .80-.96). CONCLUSIONS: Our results indicate that DNI is better than other laboratory variables for predicting postoperative mortality in patients with sepsis caused by peritonitis. DNI > 7.8% on day 3 was a reliable predictor of postoperative mortality.

Hepatitis B virus preS1 deletion is related to viral replication increase and disease progression.

AIM: To investigate the clinical implications of hepatitis B virus (HBV) preS1 deletion. METHODS: We developed a fluorescence resonance energy transfer-based real-time polymerase chain reaction (RT-PCR) that can detect four genotypes (wild type, 15-bp, 18-bp and 21-bp deletion). The PCR method was used in two cohorts of Korean chronic HBV subjects with genotype C infections. Cohort I included 292 chronic HBV subjects randomly selected from Cheju National University Hospital (Jeju, South Korea) or Seoul National University Hospital (Seoul, South Korea), and cohort II included 90 consecutive chronic HBV carriers recruited from Konkuk University Hospital (Seoul, South Korea); the cohort II patients did not have hepatocellular carcinoma or liver cirrhosis. RESULTS: The method proposed in this study identified 341 of 382 samples (89.3%). Deletion variants were identified in 100 (29.3%) of the 341 detected samples. In both cohorts, the subjects with deletions had a significantly higher Hepatitis B virus e antigen (HBeAg)-positive seroprevalence [cohort I, wild (51.0%) vs deletion (75.0%), P < 0.001; cohort II, wild (69.2%) vs deletion (92.9%), P = 0.002] and higher HBV DNA levels [cohort I, wild (797.7 pg/mL) vs deletion (1678.9 pg/mL), P = 0.013; cohort II, wild (8.3 × 10(8) copies/mL) vs deletion (2.2 × 10(9) copies/mL), P = 0.049], compared to subjects with wild type HBV. CONCLUSION: HBV genotype C preS1 deletion may affect disease progression in chronic HBV subjects through an extended duration of HBeAg seropositive status and increased HBV replications.

Prognostic significance of computed tomography defined ascites in advanced gastric cancer.

PURPOSE: The aim of this study was to investigate the clinicopathologic features and prognosis in patients with computed tomography (CT) findings of ascites, with a focus on the correlation with peritoneal carcinomatosis. METHODS: This study included a total of 157 patients who underwent surgery for advanced gastric cancer from 2003 to 2008 at the Department of Surgery, Hallym University Kangdong Sacred Heart Hospital, Seoul, Korea, which were analyzed retrospectively. RESULTS: Fourteen patients (8.9%) presented ascites on their CT scan. Among them, 10 patients had peritoneal carcinomatosis, and showed significant difference with CT ascites positive group in the incidence of peritoneal carcinomatosis. The presence of CT ascites was significantly correlated with pathologic T stage, tumor size, histologic type, CT T and N stages, CT peritoneal nodularity and curability of surgery, statistically. The prognosis of CT ascites positive group was much poorer in the total advanced gastric cancer patients (P < 0.001), as well as in patients with pathologic T4 (P = 0.002). Also in patients without peritoneal carcinomatosis, CT ascites positive subgroup tended to have a worse prognosis than CT ascites negative subgroup (P = 0.086). Tumor size, CT T and N stages and the presence of CT peritoneal nodularity and ascites influenced the prognosis significantly; among which, if a tumor size larger than 5 cm, CT T4 stage and the presence of CT ascites were identified as independent prognostic factors. CONCLUSION: The presence of ascites was closely associated with peritoneal metastasis, and was the most significant independent prognostic factor in advanced gastric cancer in the present study.

[The Comparison between 6th and 7th International Union Against Cancer/American Joint Committee on Cancer Classification for Survival Prognosis of Gastric Cancer].

BACKGROUND/AIMS: The tumor-node-metastasis (TNM) staging is an useful system to assess the prognosis of any solid cancer. As new TNM staging classification of 7th stomach cancer was revised in 2009, we evaluated the prognostic predictability of the 7th International Union Against Cancer/American Joint Committee on Cancer (UICC/AJCC) TNM classification compared to 6th UICC/AJCC TNM classification in gastric cancer. METHODS: From January 2000 to December 2009, 5-year survival rates of 266 patients with gastric cancer were calculated by the 6th and 7th UICC/AJCC TNM classification. RESULTS: Using the 7th UICC/AJCC TNM classification, there was no significant difference in the 5-year cumulative survival rates (5 YSR) between stage IIA and IIB, IIB and IIIA, and IIIA and IIIB (70% vs. 71%, p=0.530; 71% vs. 80%, p=0.703; 80% vs. 75%, p=0.576, respectively) though significant differences of the survival rates were observed among stages of 6th edition. Using T stage of 7th edition, 5 YSR was not different between T2 and T3 (86% vs. 82%, p=0.655). Using N stage of 7th edition, 5 YSR were not different between N1 and N2, N3a and N3b (79% vs. 81%, p=0.506; 41% vs. 17%, p=0.895, respectively). CONCLUSIONS: The 7th UICC/AJCC TNM classification had poor prognostic predictability in gastric cancer compared to the 6th edition.

Laparoscopic completion total gastrectomy in remnant gastric cancer: technical detail and experience of two cases.

The treatment of choice for remnant gastric cancer is resection by open conventional method, but due to adhesion and deformed anatomic structure, reoperation is one of the most complicated surgeries. We therefore introduce 2 cases of laparoscopy-assisted completion total gastrectomy. One was 67 yrs old male who had radical subtotal gastrectomy with gastrojejunostomy due to stomach cancer 30 years ago. Gastric polyp was found in routine EGD. Biopsy results showed focal adenocarcinoma and laparoscopy-assisted total gastrectomy with Roux-en-Y esophagojejunostomy was decided and performed. The other case was 65 yrs old male who went through radical subtotal gastrectomy with gastroduodenostomy 8 years ago due to stomach cancer. Recur was diagnosed by routine EGD, and laparoscopic assisted total gastrectomy with Roux-en-Y esophagojejunostomy was done. As can be seen in this study, laparoscopy-assisted gastrectomy could be safely applied in remnant gastric cancer.

Long-surviving patients with recurrent GIST after receiving cytoreductive surgery with imatinib therapy.

In the treatment of recurrent or metastatic gastrointestinal stromal tumors (GIST), good prognoses may not be expected by surgery alone. Recently, imatinib has been applied for the treatment of GISTs, resulting in improved patient survival. However, long-term success is limited due to the development of resistance. Herein, we report two cases of long-surviving patients with recurrent GIST after receiving cytoreductive surgery with imatinib therapy. A 49 year-old man was diagnosed to a duodenal GIST with single hepatic metastasis, and an antrectomy including the duodenal lesion with intraoperative radiofrequency ablation were performed in April, 2002. After four months, a new metastatic hepatic lesion was identified. Percutaneous radiofrequency ablation was done, and imatinib therapy was started. A 56 year-old man underwent laparoscopic segmental resection of the distal ileum and partial excision of parietal peritoneum in March, 2001 to treat a malignant GIST of the distal ileum that was attached to parietal peritoneum. After six months, recurrence of GIST with peritoneal seeding and hepatic metastasis was found, and he underwent cytoreductive surgery including right hemicolectomy and wedge resection of liver. After surgery, there was no residual tumor grossly and imatinib therapy was started. In both cases, they were doing well with no evidence of recurrence for 5 years with imatinib therapy. Therefore, in patients with a recurrent GIST, improved survival can be expected with imatinib therapy after cytoreductive surgery.

Changes in treatment outcomes of gastric cancer surgery over 45 years at a single institution.

PURPOSE: Although many studies have demonstrated improvements in short-and long-term outcomes of gastric cancer surgery, changes in long-term survival over time are not well-established. This study was conducted to evaluate changes in host, tumor, and treatment factors in patients treated at a single institution over a period of 45-yr. PATIENTS AND METHODS: We retrospectively evaluated 9282 patients with gastric cancer from 1955 to 1999, and divided the 45-yr into 4 time frames based on published articles: 1955 to 1962 (n=228), 1963 to 1972 (n=891), 1973 to 1988 (n=2789), and 1989 to 1999 (n=5374). RESULTS: Remarkable changes were noted in host, tumor, treatment factors, and prognosis. Among host factors, patients of more advanced age were identified in the 4th period and mean age shifted from 49 to 55 yrs. Among tumor factors, early gastric cancers and upper body tumors increased up to 32% and from 7% to 13%, respectively. An increase in the annual number of patients (from 29 to 649), gastrectomies (from 14 to 600), rate of resection (from 50% to 90%), rate of curative resection (up to 92%), and proportion of total gastrectomy (from 8% to 29%) was noted. Operative mortality was reduced from 6.1% to 0.7%. The overall 5-yr survival rate significantly increased from 22% to 65%. CONCLUSION: Treatment results of gastric cancer surgery have improved remarkably over the 45-year period. Increase of early stage gastric cancer with early diagnosis considerably influenced the improved survival of patients with gastric cancer.

Clinicopathologic characteristics and prognosis for young gastric adenocarcinoma patients after curative resection.

BACKGROUND: Conflicting results from previous studies on gastric adenocarcinoma (GC) in young patients have led to controversy surrounding the prognosis for young GC patients. METHODS: The authors studied 6954 patients with GC who received curative resections. They were classified into three groups: those aged 40 years or less ("young," 12.7%); those aged 41-65 years ("middle-aged," 66.7%); and those aged more than 65 years ("elderly," 20.6%). Clinicopathologic characteristics and overall survival rates were analyzed. RESULTS: Young patients were predominately female and had tumors that were histologically undifferentiated. However, in regard to T4 invasion, N3 lymph node metastasis, and TNM stage IV, the characteristics of the tumors of young patients were similar to those of middle-aged and elderly patients. Overall survival rate was significantly better in young patients than middle-aged patients (P = .018) and elderly patients (P < .001). Stratified by TNM stage, young patients showed better overall survival at stage I than middle-aged patients, and at stages I, II, and IIIa than elderly patients. Multivariate analysis indicated that age was an independent prognostic factor (as well as gender, operation type, depth of invasion, and lymph node status). CONCLUSIONS: The predominance of female cases and tumors that were histologically undifferentiated were distinctive characteristics in young patients. Young patients could gain a survival benefit after curative resection with stage I disease.

Risk factors for lymph node metastasis in undifferentiated early gastric cancer.

BACKGROUND: Endoscopic surgery has not been accepted as a curative treatment for intramucosal undifferentiated early gastric cancer (EGC). The purpose of this study was to evaluate the predictive factors of lymph node metastasis and explore the possibility of using endoscopic surgery for undifferentiated EGC. METHODS: We retrospectively analyzed 646 patients with undifferentiated EGC who had undergone gastrectomy with D2 lymphadenectomy from January 2000 to March 2005. We used univariate and multivariate analysis to identify clinicopathological features that were predictive factors for lymph node metastasis. RESULTS: The incidence of lymph node metastasis was 4.2% in intramucosal and 15.9% in submucosal undifferentiated EGC. Multivariate analysis revealed that submucosal invasion, larger tumor size (greater than 2 cm), and presence of lymphovascular invasion (LVI), were significantly associated with lymph node metastasis in patients with undifferentiated EGC. Tumor size and LVI were independent risk factors for lymph node metastasis in cases of intramucosal EGC. Lymph node metastasis was found in only one patient (0.5%) who had neither of the two risk factors for intramucosal EGC. CONCLUSION: Complete endoscopic resection may be acceptable as a curative treatment for intramucosal undifferentiated EGC when the tumor size is less than or equal to 2 cm, and when LVI is absent in the postoperative histological examination. Radical gastrectomy should be recommended if LVI or unexpected submucosal invasion is present.