Characterization of 3D Organotypic Culture of Mouse Adipose-Derived Stem Cells

Although stem cells are a promising avenue for harnessing the potential of adipose tissue, conventional two-dimensional (2D) culture methods have limitations. This study explored the use of three-dimensional (3D) cultures to preserve the regenerative potential of adipose-derived stem cells (ADSCs) and investigated their cellular properties. Flow cytometric analysis revealed significant variations in surface marker expressions between the two culture conditions. While 2D cultures showed robust surface marker expressions, 3D cultures exhibited reduced levels of CD44, CD90.2, and CD105. Adipogenic differentiation in 3D organotypic ADSCs faced challenges, with decreased organoid size and limited activation of adipogenesis-related genes. Key adipocyte markers, such as lipoprotein lipase (LPL) and adipoQ, were undetectable in 3D-cultured ADSCs, unlike positive controls in 2D-cultured mesenchymal stem cells (MSCs). Surprisingly, 3D-cultured ADSCs underwent mesenchymal-epithelial transition (MET), evidenced by increased E-cadherin and EpCAM expression and decreased mesenchymal markers. This study highlights successful ADSC organoid formation, notable MSC phenotype changes in 3D culture, adipogenic differentiation challenges, and a distinctive shift toward an epithelial-like state. These findings offer insights into the potential applications of 3D-cultured ADSCs in regenerative medicine, emphasizing the need for further exploration of underlying molecular mechanisms.

Clinical Efficacy of Laparoscopic Sentinel Node Navigation Surgery for Stomach Preservation in Patients With Early Gastric Cancer: 5-year Results of the SENORITA Trial

OBJECTIVE

This study aimed to compare laparoscopic standard gastrectomy (LSG) and laparoscopic sentinel node navigation surgery (LSNNS) for EGC in terms of 5-year long-term oncologic outcomes.

SUMMARY BACKGROUND DATA

The oncological safety of LSNNS for early gastric cancer (EGC) has not been confirmed. Three-year disease-free survival (DFS), which is the primary endpoint of the phase III multicenter randomized controlled clinical trial (SEntinel Node ORIented Tailored Approach [SENORITA] trial), did not show the non-inferiority of LSNNS relative to LSG.

METHODS

The SENORITA trial, a multicenter randomized clinical trial, was designed to show that LSNNS is non-inferior to LSG in terms of 3-year DFS. In the present study, we collected 5-year follow-up data from 527 patients recruited in the SENORITA trial as the full analysis set (FAS). Disease-free survival (DFS), overall survival (OS), disease-specific survival (DSS), and recurrence patterns were evaluated using the FAS of both LSG (n=269) and LSNNS (n=258).

RESULTS

The 5-year DFS was not significantly different between the LSG and LSNNS groups (P=0.0561). During the 5-year follow-up, gastric cancer-related events, such as metachronous cancer, were more frequent in the LSNNS group than in the LSG group. However, ten recurrent cancers in the remnant stomach of both groups were curatively resected by additional gastrectomy and one by additional endoscopic resection. Two of the 198 patients who underwent local resection for stomach preservation based on the LSNNS results developed distant metastasis. However, there was no statistically significant difference in the 5-year OS and DSS (P=0.7403 and P=0.9586, respectively) between the two groups.

CONCLUSION

The 5-year DFS, DSS and OS did not differ significantly between the two groups. Considering the benefits of LSNNS on postoperative quality of life, LSNNS could be recommended as an alternative treatment option for EGC.

Comparison between the mesenteric fixation method (MEFIX) and conventional methods at preventing the occurrence of Petersen's hernia: a study protocol for a multicenter randomized controlled trial

BACKGROUND

Petersen's hernia, which occurs after Billroth-II (B-II) or Roux-en-Y (REY) anastomosis, can be reduced by defect closure. This study aims to compare the incidence of bowel obstruction above Clavien-Dindo classification grade III due to Petersen's hernia between the mesenteric fixation method and the conventional methods after laparoscopic or robotic gastrectomy.

METHODS

This study was designed as prospective, single-blind, non-inferiority randomized controlled multicenter trial in Korea. Patients with histologically diagnosed gastric cancer of clinical stages I, II, or III who underwent B-II or REY anastomosis after laparoscopic or robotic gastrectomy are enrolled in this study. Participants who meet the inclusion criteria are randomly assigned to two groups: a CLOSURE group that underwent conventional Petersen's defect closure method and a MEFIX group that underwent the mesenteric fixation method. The primary endpoint is the number of patients who underwent surgery for bowel obstruction caused by Petersen's hernia within 3 years after laparoscopic or robotic gastrectomy.

DISCUSSION

This trial is expected to provide high-level evidence showing that the MEFIX method can quickly and easily close Petersen's defect without increased postoperative complications compared to the conventional method.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05105360. Registered on November 3, 2021.

Comparison of complications between laparoscopic and open gastrectomies for early gastric cancer by a nationwide propensity score-matched cohort study

The safety of laparoscopic gastrectomy compared with that of open surgery for the treatment of early gastric cancer (EGC) is unidentified on a national scale. We aimed to compare the morbidity between laparoscopic and open gastrectomies for pathological T1 gastric cancer based on nationwide survey data. Data of 14,076 patients who underwent gastric cancer surgery obtained from the 2019 Korean Gastric Cancer Association-led nationwide survey were used. For patients with pathological T1 gastric cancer, the clinical characteristics were compared between the laparoscopic and open gastrectomy groups. Propensity score matching (PSM) was performed to match the baseline characteristics of the groups. Among the 7765 patients with pathological T1 gastric cancer who underwent open or laparoscopic gastrectomy, 612 pairs were matched. After balancing the baseline characteristics, the laparoscopic gastrectomy group had a significantly longer operative time, less blood loss, greater number of harvested lymph nodes, shorter hospital stays, and comparable morbidity, compared with the open gastrectomy group (P < 0.001, P < 0.001, P < 0.001, P = 0.001, and P = 0.709, respectively). The surgical approach was not a risk factor for postoperative complication in logistic regression analysis. The PSM analysis with the 2019 Korean nationwide survey data demonstrated that laparoscopic gastrectomy showed comparable morbidity with open gastrectomy for EGC.

Concurrent laparoscopic highly selective vagotomy with closure of duodenal ulcer perforations show good clinical results as primary repair alone

OBJECTIVE

To compare clinical and operative results between laparoscopic primary repair (LPR) alone and LPR with highly selective vagotomy (LPR-HSV) in patients with duodenal ulcer perforation.

METHODS

Clinical data from patients who underwent either LPR or LPR-HSV by resecting both sides of the neurovascular bundle using an ultrasonic or bipolar electrosurgical device for duodenal ulcer perforations, between 2010 and 2020, were retrospectively collected. Between-group differences in continuous and categorical variables were statistically analysed.

RESULTS

Data from 184 patients (mean age, 49.6 years), who underwent either LPR (n = 132) or LPR-HSV (n = 52) were included. The mean operation time was significantly longer in the LPR-HSV group (116.5 ± 39.8 min) than in the LPR group (91.2 ± 33.3 min). Hospital stay was significantly shorter in the LPR-HSV group (8.6 ± 2.6 days) versus the LPR group (11.3 ± 7.1 days). The mean postoperative day of starting soft fluid diet was also significantly shorter in the LPR-HSV group (4.5 ± 1.4 days) than in the LPR group (5.6 ± 4 days). No between-group difference in morbidity rate was observed. The learning curve of the HSV procedure showed a stable procedure time after 10 operations.

CONCLUSIONS

LPR with HSV may be a safe and feasible procedure for selective cases who are at high risk for ulcer recurrence.

Complication After Gastrectomy for Gastric Cancer According to Hospital Volume: Based on Korean Gastric Cancer Association-Led Nationwide Survey Data

PURPOSE

This study aimed to analyze the incidence and risk factors of complications following gastric cancer surgery in Korea and to compare the correlation between hospital complications based on the annual number of gastrectomies performed.

MATERIALS AND METHODS

A retrospective analysis was conducted using data from 12,244 patients from 64 Korean institutions. Complications were classified using the Clavien-Dindo classification (CDC). Univariate and multivariate analyses were performed to identify the risk factors for severe complications.

RESULTS

Postoperative complications occurred in 14% of the patients, severe complications (CDC IIIa or higher) in 4.9%, and postoperative death in 0.2%. The study found that age, stage, American Society of Anesthesiologists (ASA) score, Eastern Cooperative Oncology Group (ECOG) score, hospital stay, approach methods, and extent of gastric resection showed statistically significant differences depending on hospital volumes (P<0.05). In the univariate analysis, patient age, comorbidity, ASA score, ECOG score, approach methods, extent of gastric resection, tumor-node-metastasis (TNM) stage, and hospital volume were significant risk factors for severe complications. However, only age, sex, ASA score, ECOG score, extent of gastric resection, and TNM stage were statistically significant in the multivariate analysis (P<0.05). Hospital volume was not a significant risk factor in the multivariate analysis (P=0.152).

CONCLUSIONS

Hospital volume was not a significant risk factor for complications after gastric cancer surgery. The differences in the frequencies of complications based on hospital volumes may be attributed to larger hospitals treating patients with younger age, lower ASA scores, better general conditions, and earlier TNM stages.

Treatment and Prevention of Postoperative Leakage after Gastrectomy for Gastric Cancer

Anastomotic leakage is one of the common causes of serious morbidity and death after gastrectomy. The use of surgical treatment for leakage decreased due to the development of nonsurgical management. However, if nonsurgical management fails to control the spread of intra-abdominal infection, emergency surgical treatment is required. The authors wished to determine in which cases surgical treatment is needed for postoperative leakage and to identify treatment and prevention strategies. If a patient's vital signs are stable, local abscesses can be cured by conservative treatment after percutaneous drain insertion; if there is no improvement in anastomotic leakage, endoscopic treatment such as clipping, vacuum, and stent placement can be performed. If a patient's vital signs are unstable or patient shows diffuse peritonitis, surgical treatment should be performed. A surgical plan can be established according to leakage location. The duodenal stump may first require conservative treatment. It is recommended that surgical treatment be attempted first for anastomotic leakage of gastrojejunostomy site and gastric stump in remnant stomach. In conclusion, the need for surgical treatment is determined depending on vital signs and presence of diffuse peritonitis. During surgical treatment, a strategic approach is required according to the patient's condition and the anatomical location of leakage.

Determining the precise extent of sentinel basins during laparoscopic gastrectomy for early gastric cancer

PURPOSE

By analyzing sentinel basin dissection (SBD) data from the SEntinel Node ORIented Tailored Approach (SENORITA) trial, we sought to determine the precise extent of the sentinel basin (SB) without a tracer.

MATERIALS AND METHODS

This study investigated SB length in patients (n = 25) who underwent laparoscopic SBD for early gastric cancer (EGC) in the SENORITA trial. SB length along the greater curvature (GC) and lesser curvature (LC) was measured intraoperatively before performing SBD.

RESULTS

In all 25 cases, along the LC of the stomach, the lengths of the SB were 3.7 cm [2.0-5.0] (median [min-max]) proximally and 3.0 cm [2.3-5.5] distally; along the GC side, the lengths of the SB were 6.8 cm [3.5-11.0] proximally and 7.0 cm [3.8-9.5] distally from the tumors. The SB length at the GC or LC side was not significantly different between subgroups categorized by tumor depth, size, and longitudinal location. When tumors were located at the anterior wall of the stomach, the length of the proximal SB (10.0 cm [9.0-11.0]) at the GC side was the longest. In cases with several sentinel lymph nodes (SLNs), the lengths of the SB at the GC side were significantly longer than those with fewer SLNs. However, the lengths of the SB were similar on the LC side regardless of the number of SLNs.

CONCLUSIONS

This pilot study had some limitations of a small number of enrolled patients, the lack of research on the specific station of SLNs, and the inaccurate indication for sentinel node navigation surgery (SNNS) without tracer. Nevertheless, the present study which reported the extents of SBs might be the first step towards simplifying procedures in laparoscopic SNNS for stomach preservation in EGC.

Efficacy of S-1 or Capecitabine plus Oxaliplatin Adjuvant Chemotherapy for Stage II or III Gastric Cancer after Curative Gastrectomy: A Systematic Review and Meta-Analysis

Simple Summary

Adjuvant chemotherapy regimens tegafur/gimeracil/oteracil (S-1) and capecitabine plus oxaliplatin (CAPOX) have predominated, owing to evidence of their remarkable oncologic outcomes, however, there has been a lack of studies on the difference in efficacy between the two regimens. We conducted pairwise meta-analyses comparing the efficacy of S-1 and CAPOX regimens for overall survival (OS) and disease-free survival (DFS) in stage II or III gastric cancer patients. In all stages (stages II and III), the five-year OS was not different between the two regimens (hazard ratio [HR] 0.96, 95% confidence interval [CI] 0.78–1.17; p = 0.56). Additionally, the five-year DFS was not different at any stage (HR 1.00, 95% CI 0.85–1.18; p = 0.21). The present meta-analysis showed that five-year OS and DFS for stage II or III gastric cancer patients were comparable between the S-1 and CAPOX adjuvant chemotherapy regimens.

Abstract

Background: Adjuvant chemotherapy (AC) regimens tegafur/gimeracil/oteracil (S-1) and capecitabine plus oxaliplatin (CAPOX) have predominated, however, there has been a lack of studies on their differences in efficacy. Methods: We conducted pairwise meta-analyses comparing the efficacy of S-1 and CAPOX regimens for overall survival (OS) and disease-free survival (DFS) in stage II or III GC patients. Results: Three studies were enrolled and analyzed using a forest plot for meta-analysis. Two of them were propensity score matching studies, and the remaining one was a retrospective observational study. In all stages, the five-year OS was not different between the two regimens (HR 0.96, 95% CI 0.78–1.17; p = 0.56). Additionally, the 5-year DFS was not different at any stage (HR 1.00, 95% CI 0.85–1.18; p = 0.21). After omitting the retrospective observational study, the five-year OS (HR 1.40, 95% CI 0.53–3.73) and DFS (HR 1.41, 95% CI 0.57–3.44) of S-1 tended to be better in stage II, and the five-year OS (HR 0.81, 95% CI 0.56–1.16) and DFS (HR 0.85, 95% CI 0.63–1.13) of CAPOX tended to be better in stage III, without statistical significance. Conclusions: In the present meta-analysis, the five-year OS and DFS for stage II or III GC patients were comparable between S-1 and CAPOX regimens as AC.

Clinical efficacy of laparoscopic sentinel node navigation surgery for early gastric cancer: Five-year results of SENORITA trial

4050

Background: A phase III multicenter randomized controlled clinical trial (SEntinel Node ORIented Tailored Approach [SENORITA] trial) has been performed to confirm the oncologic safety of laparoscopic sentinel node navigation surgery (LSNNS) for early gastric cancer (EGC). The results did not show the non-inferiority of LSNNS relative to laparoscopic standard gastrectomy (LSG) in terms of 3-year disease-free survival (DFS), the primary endpoint of the SENORITA trial even though the improved quality of life (QOL) in the LSNNS group. However, the long-term oncologic outcomes of LSNNS have not been compared with conventional surgery. This study was planned to investigate the comparison of LSG and LSNNS for EGC in terms of 5 years survival. Methods: We collected 5-year follow-up data of 527 patients recruited in the SENORITA trial. The overall survival (OS), disease-free survival (DFS), and recurrence pattern were evaluated in full analysis sets of both LSG (n = 269) and LSNNS (n = 258). Results: The mean follow-up period was 58.5 and 57.7 months in LSNNS and LSG groups. There was no statistically significant difference in 5-year OS (p = 0.7403) and DFS (p = 0.0561) between LSG and LSNNS. In terms of DFS, additional five events in the LSG group and 7 in LSNNS occurred after a 3-year follow-up until 5-years. Primary site recurrence in 1 LSNNS, and metachronous gastric cancer occurred in one LSG and two in LSNNS were diagnosed from 3 to 5-year follow-up period. Other organ cancer developed in two vs. three and other deaths occurred in two v s. one in each group, respectively, from 3 to 5-year follow-up. Overall survival events were 6 in LSG and 7 in LSNNS, and disease-specific death events were two patients in both groups until five years. Conclusions: Although the SENORITA trial did not show non-inferiority of LSNNS in the primary endpoint, 3-year DFS relative to LSG, the 5-year DFS and OS did not reveal the statistical difference between the two groups. Considering the benefit of LSNNS regarding the postoperative QOL, LSNNS could be recommended as an alternative treatment option of LSG for EGC. Clinical trial information: NCT01804998.

Comparison of the Clinical Outcomes of Reconstruction Methods After Distal Gastrectomy: A Systematic Review and Meta-Analysis Based on Randomized Controlled Trials

BACKGROUND

To analyze the short- and long-term clinical outcomes of 2 reconstruction methods after distal gastrectomy for gastric cancer.

METHODS

Three keywords, "gastric neoplasm," "distal gastrectomy," and "reconstruction," were used to search PubMed. We selected only randomized controlled trial that compared the anastomosis methods. A total of 11 papers and 8 studies were included in this meta-analysis. All statistical analyses were performed using the R software.

RESULTS

Among short-term clinical outcomes, a shorter operation time, reduced morbidity, and shorter hospital stay were found for Billroth type I (B-I) than for Roux-en-Y (RNY) reconstruction in the meta-analysis (P<0.001, P=0.048, P<0.001, respectively). When comparing Billroth type II (B-II) to RNY, the operation time was shorter for B-II than for RNY (P<0.019), but there were no differences in morbidity or length of hospital stay (P=0.500, P=0.259, respectively). Regarding long-term clinical outcomes related to reflux, there were significantly fewer incidents of reflux esophagitis, reflux gastritis, and bile reflux (P=0.035, P<0.001, P=0.019, respectively) for RNY than for B-I in the meta-analysis, but there was no difference between the 2 methods in residual food (P=0.545). When comparing B-II to RNY, there were significantly fewer incidents of reflux gastritis (P<0.001) for RNY than for B-II, but the amount of residual food and patient weight gain showed no difference.

CONCLUSION

B-I had the most favorable short-term outcomes, but RNY was more advantageous for long-term outcomes than for other methods. Surgeons should be aware of the advantages and disadvantages of each type of anastomosis and select the appropriate method.

Laparoscopic Sentinel Node Navigation Surgery for Stomach Preservation in Patients With Early Gastric Cancer: A Randomized Clinical Trial

PURPOSE

To compare postoperative complications, long-term survival, and quality of life (QOL) after laparoscopic sentinel node navigation surgery (LSNNS) and laparoscopic standard gastrectomy (LSG).

METHODS

Five hundred eighty patients with preoperatively diagnosed stage IA gastric adenocarcinoma (≤ 3 cm) were assigned to undergo either LSG or LSNNS. Observers were not blinded to patient grouping. The primary outcome was 3-year disease-free survival (3y-DFS). Secondary outcomes included postoperative complications, QOL, 3-year disease-specific survival (3y-DSS), and 3-year overall survival (3y-OS).

RESULTS

In total, 527 patients were included in the modified intention-to-treat analysis population for the primary outcome (LSG, 269; LSNNS, 258). Stomach-preserving surgery was performed in 210 patients (81%) in the LSNNS group. During the median follow-up duration, the 3y-DFS rates in the LSG and LSNNS groups were 95.5% and 91.8%, respectively (difference: 3.7%; 95% CI, -0.6 to 8.1). Three patients with recurrence and five with metachronous gastric cancer in the LSNNS group underwent standard surgery. Two patients with distant metastasis in both groups were treated with palliative chemotherapy. The 3y-DSS and 3y-OS rates in the LSG and LSNNS groups were 99.5% and 99.1% (P = .59) and 99.2% and 97.6% (P = .17), respectively. Postoperative complications occurred in 19.0% of the LSG group and 15.5% of the LSNNS group (P = .294). The LSNNS group showed better physical function (P = .015), less symptoms (P < .001), and improved nutrition than the LSG group.

CONCLUSION

LSNNS did not show noninferiority to LSG for 3y-DFS, with a 5% margin. However, the 3y-DSS and 3y-OS were not different after rescue surgery in cases of recurrence/metachronous gastric cancer, and LSNNS had better long-term QOL and nutrition than LSG.

Long-Term Survival Outcomes of Elderly Patients Treated With S-1 or Capecitabine Plus Oxaliplatin for Stage II or III Gastric Cancer: A Multicenter Cohort Study

Purpose

Materials and Methods

Results

Conclusions

A comparison of quality of life between patients with small and large gastric remnant volumes after gastrectomy for gastric cancer

The impact of gastric remnant volumes (GRVs) after gastrectomy on patients' quality of life (QOL) has not yet been clarified. The aim of the present study was to compare QOL after gastrectomy between small and large gastric remnant volume patients.We prospectively collected clinical data from 78 consecutive patients who underwent distal gastrectomy with Billroth II gastrojejunostomy for gastric cancer. The European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Stomach questionnaire and gastric computed tomography scans were performed. The patients were subdivided into 2 groups by remnant stomach volume (the S group ≤110 mL vs L group >110 mL).The worst scores for most items were observed at postoperative month 1 and usually improved thereafter. There was no difference in the STO22 score except for dysphagia between the S and L groups after gastrectomy (P > .05). The QOL score of dysphagia was different at postoperative 6 months (S vs L, 12.4 vs 22.8, P < .03), but there was no difference at postoperative months 1, 3, 12, 24, or 36 (P > .05).The remnant gastric volume after partial gastrectomy affects neither functional differences nor QOL after 6 months following appropriate radical surgery.

Choice of LECS Procedure for Benign and Malignant Gastric Tumors

Laparoscopic endoscopic cooperative surgery (LECS) refers to the endoscopic dissection of the mucosal or submucosal layers with laparoscopic seromuscular resection. We recommend a treatment algorithm for the LECS procedure for gastric benign tumors according to the protruding type. In the exophytic type, endoscopic-assisted wedge resection can be performed. In the endophytic type, endoscopic-assisted wedge resection of the anterior wall is relatively easy to perform, and endoscopic-assisted transgastric resection, laparoscopic-assisted intragastric surgery, or single-incision intragastric resection in the posterior wall and esophagogastric junction (EG Jx) can be attempted. We propose an algorithm for the LECS procedure for early gastric cancer according to the tumor location. The endoscopic submucosal dissection (ESD) procedure can be adapted for all areas of the stomach, and single-incision ESD can be performed in the mid to high body and the EG Jx. In full-thickness gastric resection, laparoscopy-assisted endoscopic full-thickness resection can be adapted for the entire area of the stomach, but it cannot be applied to the pyloric and EG Jx. In conclusion, surgeons need to select the LECS procedure according to tumor type, tumor location, the surgeon's individual experience, and the situation of the institution while also considering the advantages and disadvantages of each procedure.

A comparison of postoperative outcomes after open and laparoscopic reduction of Petersen's Hernia: a multicenter observational cohort study

BACKGROUND

The aim of this multicenter cohort study was to compare the clinical courses between open and laparoscopic Petersen's hernia (PH) reduction.

METHOD

We retrospectively collected the clinical data of patients who underwent PH repair surgery after gastrectomy for gastric cancer from 2015-2018. Forty patients underwent PH reduction operations that were performed by six surgeons at four hospitals. Among the 40 patients, 15 underwent laparoscopic PH reduction (LPH), and 25 underwent open PH reduction (OPH), including 4 patients who underwent LPH but required conversion to OPH.

RESULTS

We compared the clinical factors between the LPH and OPH groups. In the clinical course, we found no differences in operation times or intraoperative bowel injury, morbidity, or mortality rates between the two groups (p > 0.05). However, the number of days on a soft fluid diet (OPH vs. LPH; 5.8 vs. 3.7 days, p = 0.03) and length of hospital stay (12.6 vs. 8.2 days, p = 0.04) were significantly less in the LPH group than the OPH group. Regarding postoperative complications, the OPH group had a case of pneumonia and sepsis with multi-organ failure, which resulted in mortality. In the LPH group, one patient experienced recurrence and required reoperation for PH.

CONCLUSION

Laparoscopic PH reduction was associated with a faster postoperative recovery period than open PH reduction, with a similar incidence of complications. The laparoscopic approach should be considered an appropriate strategy for PH reduction in selected cases.

Intraoperative Tumor Localization of Early Gastric Cancers

Recently, endoscopic screening systems have enabled the diagnosis of gastric cancer in the early stages. Early gastric cancer (EGC) is typically characterized by a shallow invasion depth and small size, which can hinder localization of EGC tumors during laparoscopic surgery. Here, we review nine recently reported tumor localization methods for the laparoscopic resection of EGCs. Preoperative dye or blood tattooing has the disadvantage of spreading. Preoperative 3-dimensional computed tomography reconstruction is not performed in real time during laparoscopic gastrectomy. Thus, they are considered to have a low accuracy. Intraoperative portable abdominal radiography and intraoperative laparoscopic ultrasonography methods can provide real-time feedback, but these methods require expertise, and it can be difficult to define the clips in some gastric regions. Despite a few limitations, intraoperative gastrofibroscopy provides real-time feedback with high accuracy. The detection system using an endoscopic magnetic marking clip, fluorescent clip, and radio-frequency identification detection system clip is considered highly accurate and provides real-time feedback; we expect a commercial version of this setup to be available in the near future. However, there is not yet an easy method for accurate real-time detection. We hope that improved devices will soon be developed and used in clinical settings.

Appropriate Number of Adjuvant Chemotherapy Cycles for Patients with Stage 2 or 3 Gastric Cancer After Curative Gastrectomy: A Multicenter Cohort Study

BACKGROUND

Few studies have presented evidence pertaining to the adequate minimum number of adjuvant chemotherapy (AC) cycles required to achieve an oncologic benefit for gastric cancer.

METHODS

From January 2012 to December 2013, data from patients who underwent curative radical gastrectomy and consequently received AC for pathologic stage 2 or 3 gastric cancer at 27 institutions in South Korea were analyzed.

RESULTS

The study enrolled 925 patients, 661 patients (71.5%) who completed 8 cycles of AC and 264 patients (28.5%) who did not. Compared with the mean disease-free survival (DFS) of the patients who completed 8 AC cycles (69.3 months), the mean DFS of patients who completed 6 AC cycles (72.4 months; p = 0.531) and those who completed 7 AC cycles (63.7 months; p = 0.184) did not differ significantly. However, the mean DFS of the patients who completed 5 AC cycles (48.2 months; p = 0.016) and those who completed 1-4 AC cycles (62.9 months; p = 0.036) was significantly lower than the DFS of those who completed 8 AC cycles. In the multivariate Cox proportional hazards analysis, the mean DFS was significantly affected by advanced stage, large tumor size, positive vascular invasion, and number of completed AC cycles (1-5 cycles: hazard ratio 1.45; 95% confidence interval 1.01-2.08; p = 0.041).

CONCLUSION

The current multicenter observational cohort study showed that the mean DFS for 6 or 7 AC cycles was similar to that for 8 AC cycles as an adjuvant treatment for gastric cancer.

Prevention of Petersen's hernia using jejunal mesentery fixing (Mefix)

BACKGROUND

The aim of this study was to compare the 1 year incidence of Petersen's hernia between individuals who were treated with the jejunal mesentery fixing (Mefix) method and those with the closure of Petersen's space method.

MATERIAL AND METHODS

We retrospectively collected clinical data of patients who underwent gastrectomy for gastric cancers with the closure of Petersen's space defect (N = 49) and Mefix (N = 26). The Mefix method was performed by fixing the jejunal mesentery (jejunojejunostomy below 30 cm) to the transverse mesocolon using nonabsorbable barbed sutures.

RESULTS

The procedure time for mesentery fixing (3.7 ± 1.1 mins) was significantly shorter than that for Petersen's space closure (7.5 ± 1.5 mins) (p < .001) although the operation times were similar between the two groups. There was no incidence of Petersen's hernias postoperatively in both groups. One case of reoperation was reported in the closure group due to small bowel obstruction by kinking of the jejunojejunostomy.

CONCLUSION

We found no occurrence of Petersen's hernias postoperatively in either group. We also found that the Mefix method was faster and easier to perform than the closure method. The Mefix method is an excellent alternative method to prevent the occurrence of Petersen's hernia after B-II or Roux-en-Y reconstruction.

Long-term Efficacy of S-1 Monotherapy or Capecitabine Plus Oxaliplatin as Adjuvant Chemotherapy for Patients with Stage II or III Gastric Cancer after Curative Gastrectomy: a Propensity Score-Matched Multicenter Cohort Study

Purpose

To compare long-term disease-free survival (DFS) between patients receiving tegafur/gimeracil/oteracil (S-1) or capecitabine plus oxaliplatin (CAPOX) adjuvant chemotherapy (AC) for gastric cancer (GC).

Materials and Methods

This retrospective multicenter observational study enrolled 983 patients who underwent curative gastrectomy with consecutive AC with S-1 or CAPOX for stage II or III GC at 27 hospitals in Korea between February 2012 and December 2013. We conducted propensity score matching to reduce selection bias. Long-term oncologic outcomes, including DFS rate over 5 years (over-5yr DFS), were analyzed postoperatively.

Results

The median and longest follow-up period were 59.0 and 87.6 months, respectively. DFS rate did not differ between patients who received S-1 and CAPOX for pathologic stage II (P=0.677) and stage III (P=0.899) GC. Moreover, hazard ratio (HR) for recurrence did not differ significantly between S-1 and CAPOX (reference) in stage II (HR, 1.846; 95% confidence interval [CI], 0.693–4.919; P=0.220) and stage III (HR, 0.942; 95% CI, 0.664–1.337; P=0.738) GC. After adjustment for significance in multivariate analysis, pT (4 vs. 1) (HR, 11.667; 95% CI, 1.595–85.351; P=0.016), pN stage (0 vs. 3) (HR, 2.788; 95% CI, 1.502–5.174; P=0.001), and completion of planned chemotherapy (HR, 2.213; 95% CI, 1.618–3.028; P<0.001) were determined as independent prognostic factors for DFS.

Conclusions

S-1 and CAPOX AC regimens did not show significant difference in over-5yr DFS after curative gastrectomy in patients with stage II or III GC. The pT, pN stage, and completion of planned chemotherapy were prognostic factors for GC recurrence.

A multi-center prospective randomized controlled trial (phase III) comparing the quality of life between laparoscopy-assisted distal gastrectomy and totally laparoscopic distal gastrectomy for gastric Cancer (study protocol)

BACKGROUND

KLASS (the Korean Laparoendoscopic Gastrointestinal Surgery Study) is a time-honored study group that has established laparoscopic surgery for gastrointestinal disease in Korea and has performed some important studies for the rationale of laparoscopic gastrointestinal surgery. A multi-center RCT (randomized controlled trial) to compare the quality of life (QOL) of patients undergoing totally laparoscopic distal gastrectomy (TLDG) and laparoscopy-assisted distal gastrectomy (LADG) for gastric cancer, named as KLASS 07, has been currently prepared in Korea.

METHODS

Patients diagnosed as gastric cancer, with clinical stage IA (T1N0M0) or IB (T1N1M0 / T2N0M0) according to the 7th edition of the Americal Joint Committee on Cancer System, were randomized to receive either TLDG or LADG. For surgical quality control, the surgeons participating in this trial had to have performed at least 50 gastrectomies and at least 30 gastrectomies annually (regardless of open or laparoscopic surgery for gastric cancer). The patients who are allocated to TLDG group undergo intracorporeal anastomosis and those who are assigned to LADG undergo extracorporeal anastomosis for gastrointestinal reconstruction.

DISCUSSION

Thirty-one surgeons from 26 institutions were engaged in this trial. The primary endpoint is 30-day morbidity, and secondary endpoint is QOL assessed by the questionnaire score. The KLASS 07 trial is the first multi-center RCT to investigate whether there are significant and quantifiable differences between the QOL of TLDG and LADG. The findings from this trial are expected to be the critical clues for designing the detailed procedures during laparoscopic surgery for gastric cancer.

TRIAL REGISTRATION

The protocol of KLASS 07 (CKLASS 01) was registered in http://register.clinicaltrials.gov as NCT03393182 (Date of registration: January 2nd, 2018.).

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.

Efficacy of Adjuvant S-1 Versus XELOX Chemotherapy for Patients with Gastric Cancer After D2 Lymph Node Dissection: A Retrospective, Multi-Center Observational Study

BACKGROUND

After curative resection of gastric cancer with D2 lymph node dissection, postoperative adjuvant chemotherapy with S-1 or capecitabine plus oxaliplatin (XELOX) is considered to be standard therapy in Eastern countries. This study aimed to compare the efficacies of adjuvant S-1 and XELOX chemotherapy for gastric cancer patients after D2 dissection based on disease-free survival (DFS).

METHODS

This retrospective observational study was conducted at 29 tertiary hospitals in Korea. Of 1898 patients who underwent curative resection and received adjuvant chemotherapy for gastric cancer between February 2012 and December 2013, 1088 patients who met the eligibility criteria were enrolled in the study. After propensity score-matching, the 3-year disease-free survival rate (DFS) was used to compare efficacies directly between adjuvant XELOX and S-1 chemotherapies for patients with stage 2 or 3 gastric cancer after D2 gastrectomy.

RESULTS

The 3-year DFS rates for the S-1 and XELOX groups did not differ significantly among disease stages 2A, 2B, and 3A (all p > 0.05). However, the survival rates for the S-1 group were significantly lower than for the XELOX group for stage 3B (65.8% vs. 68.6%; p = 0.019) and stage 3C (48.4% vs. 66.7%; p = 0.002) gastric cancer. The hazard ratios (HRs) of S-1 chemotherapy for recurrence compared with XELOX for stages 3B and 3C were respectively 2.030 [95% confidence interval (CI), 1.110-3.715; p = 0.022] and 2.732 (95% CI 1.427-5.234; p = 0.002).

CONCLUSIONS

Adjuvant XELOX chemotherapy was more effective than S-1 for patients with stage 3B or 3C gastric cancer after D2 lymph node dissection.

Assessment of laparoscopic stomach preserving surgery with sentinel basin dissection compared with standard gastrectomy with lymphadenectomy in early gastric cancer: A study protocol of a multicenter randomized phase III clinical trial (SENORITA trial)

TPS179

Background: Along with marked increase in early gastric cancer (EGC) in Eastern countries, there has been an effort to adopt sentinel node concept in EGC to reduce immediate postoperative complications and preserve gastric function. Based on the promising results from the previous quality control study prior to phase III trial, this prospective multicenter randomized controlled trial aimed to elucidate the oncologic safety of laparoscopic stomach-preserving surgery with sentinel basin dissection (SBD) compared to standard laparoscopic gastrectomy. Methods: This trial is an investigator-initiated, open-label, multicenter randomized controlled phase III trial with non-inferiority design. Patients diagnosed with a single lesion of clinical stage T1N0M0 gastric adenocarcinoma with a diameter of 3cm or less are eligible for the present study. A total of 580 patients (290 per each group) will be randomized to either laparoscopic stomach-preserving surgery with SBD or standard surgery. The primary end-point is 3-year disease-free survival (DFS) and the secondary endpoints include postoperative morbidity and mortality, quality of life, and 5-year DFS and overall survival. The qualified investigators who completed the prior quality control study are exclusively allowed to participate in this phase III clinical trial. Discussion: The proposed trial is expected to verify whether laparoscopic stomach-preserving surgery with SBD achieves the similar oncologic outcomes and improved quality of life compared to the standard gastrectomy in EGC patients. Clinical trial information: NCT01804998.

Efficacy of Pre- and Postoperative Chemotherapy in Patients with Osteosarcoma of the Extremities

PURPOSE

We evaluated the treatment efficacy including survival and recurrence, and factors associated with recurrence in osteosarcoma patients treated with preoperative chemotherapy, surgery, and adjuvant chemotherapy.

MATERIALS AND METHODS

Forty nine patients with osteosarcoma were treated with preoperative chemotherapy with intra-arterial cisplatin and adriamycin infusion for 3 cycles, followed by surgery. According to the pathologic response, if tumor was necrotized more than 90%, the same adjuvant chemotherapy was reintroduced for 3 cycles, and if the response was not enough, then the salvage regimen was introduced. Plain chest film and chest CT scan were taken monthly and every 3 months, respectively. When tumor recurred, the metastasectomy was performed whenever possible.

RESULTS

Forty three patients were evaluable with amedian follow up of 53 months. Five-year disease-free and overallsurvival rate was 47.0% and 66.9%, respectively. The recurrence was observed in 22 patients (51.2%) with median time of 12.5 months. Baseline alkaline phosphatase (ALP) was the only significant factor for recurrence (p=0.03) and the patients with the possibility of metastasectomy recurrence showed higher post-relapse survival compared to other treatment modalities (26 momths vs 5~12 months).

CONCLUSION

These results indicates that pre- and postoperative chemotherapy with intra-arterial cisplatin and adriamycin infusion showed comparable treatment efficacy and acceptable toxicities.

Time-Dependent Effects of Prognostic Factors in Advanced Gastric Cancer Patients

PURPOSE

This study aimed to identify time-dependent prognostic factors and demonstrate the time-dependent effects of important prognostic factors in patients with advanced gastric cancer (AGC).

MATERIALS AND METHODS

We retrospectively evaluated 3,653 patients with AGC who underwent curative standard gastrectomy between 1991 and 2005 at the Korea Cancer Center Hospital. Multivariate survival analysis with Cox proportional hazards regression was used in the analysis. A non-proportionality test based on the Schoenfeld residuals (also known as partial residuals) was performed, and scaled Schoenfeld residuals were plotted over time for each covariate.

RESULTS

The multivariate analysis revealed that sex, depth of invasion, metastatic lymph node (LN) ratio, tumor size, and chemotherapy were time-dependent covariates violating the proportional hazards assumption. The prognostic effects (i.e., log of hazard ratio [LHR]) of the time-dependent covariates changed over time during follow-up, and the effects generally diminished with low slope (e.g., depth of invasion and tumor size), with gentle slope (e.g., metastatic LN ratio), or with steep slope (e.g., chemotherapy). Meanwhile, the LHR functions of some covariates (e.g., sex) crossed the zero reference line from positive (i.e., bad prognosis) to negative (i.e., good prognosis).

CONCLUSIONS

The time-dependent effects of the prognostic factors of AGC are clearly demonstrated in this study. We can suggest that time-dependent effects are not an uncommon phenomenon among prognostic factors of AGC.

Prospective multicenter feasibility study of laparoscopic sentinel basin dissection for organ preserving surgery in gastric cancer: Quality control study for phase III trial

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Background: Clinical application of sentinel node biopsy (SNB) in early gastric cancer (EGC) is still controversial even though promising multicenter trial result with minimal false negatives was already reported from Japan. Moreover laparoscopic approach is considered as minimally invasive in addition to organ preserving surgery. Therefore we conducted this study as a prerequisite quality control for phase III trial. Methods: Laparoscopic SBD was performed in patients with preoperative stage T1-2N0 and tumor size less than 4cm in maximal diameter. Intraoperative endoscopic submucosal injection of Technetium 99m-Human Serum Albumin and indocyanine green was done. All removed sentinel basin nodes (SBN) were investigated with intraoperative frozen Hematoxylin Eosin (HE) stain. Postoperative permanent HE stain was done for SBNs and non-SBNs. Strict checklist consisting of essential 7 steps during laparoscopic SBD was made as the quality control study for phase III trial. Ten cases completion of all essential steps in checklist were defined as qualified institution. Results: Seven institutions participated and 112 patients were enrolled in this study. However 4 patients were excluded due to screening failure. SB detection and SBD was performed in 100 of the 108. Lymph node metastases were found in 11 patients at postoperative permanent HE staining and SBD contained metastatic lymph nodes in 11 patients. The detection rate of SB was 92.6% with mean number of SB and SBN was 1.68 and 9.56. Sensitivity and accuracy were 100% in this study. Frozen results of SBN were compatible with permanent reports except one patient who had one SBN with micrometastasis. As the quality control of each institution for phase III trial, 13 to 20 cases were needed based on our strict checklist. Conclusions: Laparoscopic SBD is feasible and improve the sensitivity comparing to the previous study. This study suggests the promising phase III trial of laparoscopic SBD for minimally invasive and organ preserving surgery in EGC after qualifying participating institutions. Clinical trial information: NCT01544413.

Risk stratification for serosal invasion using preoperative predictors in patients with advanced gastric cancer

Purpose

Although serosal invasion is a critical predisposing factor for peritoneal dissemination in advanced gastric cancer, the accuracy of preoperative assessment using routine imaging studies is unsatisfactory. This study was conducted to identify high-risk group for serosal invasion using preoperative factors in patients with advanced gastric cancer.

Materials and Methods

We retrospectively analyzed clinicopathological features of 3,529 advanced gastric cancer patients with Borrmann type I/II/III who underwent gastrectomy at Korea Cancer Center Hospital between 1991 and 2005. We stratified patients into low- (≤40%), intermediate- (40~70%), and high-risk (>70%) groups, according to the probability of serosal invasion.

Results

Borrmann type, size, longitudinal and circumferential location, and histology of tumors were independent risk factors for serosal invasion. Most tumors of whole stomach location or encircling type had serosal invasion, so they belonged to high-risk group. Patients were subdivided into 12 subgroups in combination of Borrmann type, size, and histology. A subgroup with Borrmann type II, large size (≥7 cm), and undifferentiated histology and 2 subgroups with Borrmann type III, large size, and regardless of histology belonged to high-risk group and corresponded to 25% of eligible patients.

Conclusions

This study have documented high-risk group for serosal invasion using preoperative predictors. And risk stratification for serosal invasion through the combination with imaging studies may collaboratively improve the accuracy of preoperative assessment, reduce the number of eligible patients for further staging laparoscopy, and optimize therapeutic strategy for each individual patient prior to surgery.

Phenotypic Differences of Gastric Cancer according to the Helicobacter pylori Infection in Korean Patients

Purpose

Infection with Helicobacter pylori is an important risk factor for gastric cancer in humans. We compared the clinicopathologic features of gastric cancer patients based on H. pylori infection.

Materials and Methods

We prospectively studied 155 patients who had gastric cancer and underwent gastrectomies in 1 hospital in Korea. We examined H. pylori infections using the rapid urease test (RUT) with gastrectomy specimens and collected clinical and pathologic data.

Results

The number of H. pylori infections based on the RUT was 137 (88%). The H. pylori-negative group was significantly associated with AGC and tumor histology. H. pylori infection was significantly correlated with type I/IIa in EGC and type III/IV/V in AGC. AGC was significantly correlated with larger tumor size, lymphatic invasion, perineural invasion, and H. pylori infection based on univariate and multivariate analyses.

Conclusions

We report the prevalence of H. pylori based on the RUT in gastric cancer patients. H. pylori infection influences the tumor histology, progression, and growth type of gastric cancer.

Control of microorganisms and reduction of biogenic amines in chicken breast and thigh by irradiation and organic acids

The effect of irradiation or organic acid treatment of raw chicken breast and thigh meat to control inoculated microorganisms and the production of biogenic amines (BA) was studied. Bacillus cereus, Enterobacter cloacae, and Alcaligenes faecalis were selected and inoculated into raw ground chicken breast and thigh meat at approximately 10(7) cfu/g. The samples were irradiated at 0, 0.5, 1, and 2 kGy or mixed with a 0.2 M solution of acetic, citric, or lactic acid (1 mL for 10 g of meat sample) for 24 h at 4 degrees C. Viable cell counts and BA contents were determined. Irradiation was effective in reducing the inoculated bacteria: 0.5 kGy achieved approximately a 2-log reduction, and no viable cells were detected at a dose of 2 kGy. In contrast, only up to a 1-log reduction was achieved by organic acid treatment except for citric acid, which achieved approximately a 3-log reduction of E. cloacae. Both the irradiation and organic acid treatment of raw chicken breast and thigh reduced the BA content, but the rate of BA reduction differed by inoculated organism and treatment (irradiation or organic acid). Although irradiation was an excellent method for controlling inoculated microorganisms, the content of BA produced was similar to that of the organic acid treatment of raw chicken breast and thigh meat.

Phase III trial of adjuvant 5-fluorouracil and adriamycin versus 5-fluorouracil, adriamycin, and polyadenylic-polyuridylic acid (poly A:U) for locally advanced gastric cancer after curative surgery: final results of 15-year follow-up

BACKGROUND

This phase III trial was to compare 5-fluorouracil (5-FU), adriamycin, and polyadenylic-polyuridylic acid (poly A:U) against 5-fluorouracil plus adriamycin (FA) for operable gastric cancer.

PATIENTS AND METHODS

From 1984 to 1989, patients who had D(2-3) curative resection were randomly assigned to receive chemotherapy or chemoimmunotherapy. Chemotherapy consisted of 12 mg/kg 5-FU every week for 18 months and 40 mg/m2 adriamycin every 3 weeks for 12 cycles. Chemoimmunotherapy consisted of FA plus 100 mg of poly A:U weekly for six cycles and was followed 6 months later by six weekly 50-mg booster injections.

RESULTS

A total of 292 patients were enrolled. After excluding 12 ineligible patients, 142 and 138 patients were allocated to each treatment. Patients were balanced with prognostic variables: age, sex, tumor location, differentiation, degree of tumor invasion (T2-T4a), and lymph node status (N0-N2). During the 15-year follow-up, chemoimmunotherapy significantly prolonged overall (P = 0.013) and recurrence-free (P = 0.005) survivals compared with chemotherapy alone. The survival benefits were prominent in the subset of patients with T3/T4a, N2, or stage III. Treatments were generally well tolerated in both arms.

CONCLUSIONS

These results indicate a survival advantage of chemoimmunotherapy with a regimen of FA and poly A:U in curatively resected gastric adenocarcinoma.

The prognosis of stage IV gastric carcinoma patients after curative resection

BACKGROUND/AIMS

In the UICC staging system, stage IV contains not only those patients with distant metastasis but also patients with far-advanced T and N status but without distant metastasis. We investigated the prognostic factors of stage IV gastric carcinoma patients, without distant metastasis after curative resection and the role of surgery.

METHODOLOGY

One hundred and ninety stage IV gastric carcinoma patients, without distant metastasis were reviewed after curative resection in our hospital from January 1987 to December 1996.

RESULTS

Male sex, distal third location, diffuse or infiltrative type and histologically undifferentiated type were common. Of the 190 patients, 52 (27.4%) patients lived more than 3 years. The lymph node ratio (positive lymph node/retrieved lymph node) and combined resection independently affected survival (P = 0.0013, 0.0061, respectively). The perigastric lymph node ratio was well correlated with overall lymph node ratio (r = 0.794, P < 0.001).

CONCLUSIONS

With the involvement of an adjacent organ and knowing the perigastric lymph node ratio, the surgeon can decide upon the extent of dissection and postoperative treatment. However, a prospective study is warranted.

DNA ploidy patterns in advanced gastric carcinoma; is it a clinically applicable prognosticator?

BACKGROUND/AIMS

The purpose of this study was to evaluate the prognostic significance of ploidy patterns as determined by flow cytometry in terms of clinical usefulness.

METHODOLOGY

270 patients with a diagnosis of advanced gastric carcinoma were studied with fresh specimens obtained from multiple site avoiding nonviable or nonneoplastic tissues by DNA flow cytometry. DNA ploidy and clinicopathologic factors were compared and survival was analyzed.

RESULTS

The mean age of the patients was 56.1 +/- 11.6 years (25-80 years). There were 195 males and 75 females. Aneuploidy was shown in 93 (35.9%) patients. Male sex and differentiated tumor were more frequent in aneuploidy than diploidy (P = 0.011, < 0.001, respectively). By univariate analysis, tumor location, size, extent of resection, curative resection, serosa invasion, lymph node involvement, and distant metastasis significantly affected survival but not aneuploidy. Significant independent prognostic factors by multivariate analysis were curative resection, serosa invasion and lymph node involvement (P = 0.0001, 0.0114, 0.0262, respectively).

CONCLUSIONS

DNA ploidy patterns of advanced gastric carcinoma are of limited clinical significance, therefore not a clinically applicable prognosticator.

Ultralow anterior resection and coloanal anastomosis for distal rectal cancer: functional and oncological results

We evaluated the functional and oncological outcome of ultralow anterior resection and coloanal anastomosis (CAA), which is a popular technique for preserving anal sphincter in patients with distal rectal cancer. Forty-eight patients were followed up for 6-100 months regarding fecal or gas incontinence, frequency of bowel movement, and local or systemic recurrence. The main operative techniques were total mesorectal excision with autonomic nerve preservation; the type of anastomosis was straight CAA, performed by the perianal hand sewn method in 38 cases and by the double-stapled method in 10. Postoperative complications included transient urinary retention (n=7), anastomotic stenosis (n=3), anastomotic leakage (n=3), rectovaginal fistula (n=2), and cancer positive margin (n=1; patient refused reoperation). Overall there were recurrences in seven patients (14.5%): one local and one systemic recurrence in stage B2; and one local, two systemic, and two combined local and systemic in C2. The mean frequency of bowel movements was 6.1 per day after 3 months, 4.4 after 1 year, and 3.1 after 2 years. The Kirwan grade for fecal incontinence was 2.7 after 3 months, 1.8 after 1 year, and 1.5 after 2 years. With careful selection of patients and good operative technique, CAA can be performed safely in distal rectal cancer. Normal continence and acceptable frequency of bowel movements can be obtained within 1 year after operation without compromising the rate of local recurrence.

p53, BCL-2, and Ki-67 expression according to tumor response after concurrent chemoradiotherapy for advanced rectal cancer

BACKGROUND

Concurrent chemoradiotherapy (CCRT) for locally advanced rectal cancer is an important modality for curative resection, but tumors show wide spectrum response. The purpose of this study was to investigate any correlation among related genetic mutations, proliferative index, and tumor response after CCRT.

METHODS

This study included 23 patients with rectal cancer, who were preoperatively staged as at least T3 N1 or T4 (determined by transrectal ultrasonography and MRI). Enrolled patients were given 5-FU 450 mg/m2/day and leucovorin 20 mg/m2/day intravenously for 5 days during weeks 1 and 5 of radiotherapy (45-54 Gy). Surgical resection was performed 4 weeks after completion of the scheduled treatment. Tumor response was classified as CR (complete response), PR (partial response: 50% diminution of tumor volume and downstaging), and NR (no response). Paraffin-embedded tissue obtained before chemoradiotherapy was studied by immunohistochemical staining for p53, BCL-2, and Ki-67. The extent of tumor response was correlated with proliferative activity and was measured by immunostaining Ki-67 proliferative antigen and the expression of p53 and BCL-2 oncoproteins.

RESULTS

All patients were resectable. CR was obtained in 4 patients, PR in 10 patients, and NR in 9 patients. The p53 mutation was noted in 16 patients: NR in 5 patients, PR in 9 patients, and CR in 2 patients (P = .638). BCL-2 expression was noted in 11 patients: NR in 4 patients, PR in 3 patients, and CR in 4 patients (P = .799). The Ki-67 labeling index was NR: 615.4+/-47.2; PR: 663.2+/-20.4; and CR: 765.5+/-58.3 (CR + PR vs. NR, P = .029).

CONCLUSIONS

Immunohistochemical expression of p53 and BCL-2 does not correlate with tumor response after CCRT, but Ki-67 labeling may be a useful parameter for radiosensitive tumors selected for CCRT.

Impact of splenectomy for lymph node dissection on long-term surgical outcome in gastric cancer

BACKGROUND

In the treatment of gastric cancer, splenectomy is performed for effective lymph node dissection around the splenic artery and splenic hilum. The purpose of this study was to clarify the long-term outcome of splenectomy in the treatment of gastric cancer.

METHODS

The effect of splenectomy on recurrence and prognosis was examined in a retrospective analysis of 665 patients who had undergone curative total gastrectomy for gastric carcinoma from 1987 to 1996. The risk factors associated with recurrence and prognosis were investigated by univariate and multivariate analysis.

RESULTS

The splenectomy group showed more advanced lesions and a higher recurrence rate than the spleen-preserved group. However, after adjusting for the TNM (tumor, node, metastasis) stage, there was no significant difference in recurrence rate and pattern between the two groups. Logistic regression analysis revealed that gross type, serosal invasion, and nodal metastasis were independent risk factors for recurrence while splenectomy was not. When comparing patients with the same TNM (tumor, node, metastasis) stages, no significant difference in the 5-year survival rates was apparent. Multivariate analysis demonstrated that age, serosal invasion, and nodal metastasis were independent prognostic factors whereas splenectomy was not.

CONCLUSIONS

These data suggest that splenectomy for lymph node dissection in gastric cancer is not effective regarding long-term patient prognosis.

Monthly 5-days 5-fluorouracil and low-dose leucovorin for adjuvant chemotherapy in colon cancer

We investigated the dose-related effect of the 5-fluorouracil (5-FU)/leucovorin regimen on survival in 139 colon cancer patients with Dukes' B2 and C2 stage disease. Chemotherapy consisted of 400 mg/m(2) of 5-FU and 20 mg/m(2) of leucovorin injected daily for 5 days in every 4 weeks for a maximum of 12 cycles. The total dose of 5-FU administered per body surface area had a significant effect on the 5-year disease-free survival and 5-year overall survival in stage B2 and C2 colon cancer patients (P=0.0018, P=0.0011). Analysis with reference to the median DSDI demonstrated that there was a significant difference in 5-year survival in Dukes' C2 (P=0.0016), but survival was not affected by the dose intensity. Multivariate analysis demonstrated that only the total dose of 5-FU administered per surface area affected the 5-year disease-free survival and 5-year overall survival (P=0.0016, P=0.0007, respectively). It can be concluded that the total dose of 5-FU administered is important in planned dosage schedule of adjuvant chemotherapy in colon cancer.

Adjuvant 5-fluorouracil plus doxorubicin in D2-3 resected gastric carcinoma: 15-year experience at a single institute

BACKGROUND

The authors evaluated the efficacy of adjuvant chemotherapy with 5-fluorouracil (5-FU) plus doxorubicin in gastric carcinoma after D2-3 curative resection. They also evaluated the effect of dose-related factors (delivered total dose/m(2), actual dose intensity [ADI], relative dose intensity [RDI]) of this regimen on patient survival.

METHODS

A total of 301 patients with Stage II to IV (en bloc resected T4b; 1984 American Joint Committee on Cancer staging) were accrued between 1984 and 1996. Chemotherapy was started within 4 weeks of surgery according to the following schedule: intravenous bolus injection of doxorubicin 40 mg/m2 every 3 weeks for 12 cycles and 5-FU 400 mg/m2 weekly for 60 weeks. The toxicity and survival were evaluated.

RESULTS

The median follow-up duration was 58 months. Sixty-four percent of the total patients and 71.7% of the patients who did not experience recurrence during the chemotherapy finished the protocol completely with acceptable toxicities. The 5- and 10-year disease free survival rates of total 301 patients were 58.4% and 46.5%, and the overall survival rates were 62.1% and 50.5%, respectively. Treatment completion group showed survival benefit over the early termination group in 5-year survival (75.2% vs. 52.9%; P = 0.0005). The median ADI of 5-FU and doxorubicin were 349 and 11 mg/m2/week, and the median RDIs of 5-FU and doxorubicin were 0.87 and 0.83, respectively. Multivariate analysis demonstrated that completion of chemotherapy is an independent prognostic factor of both disease free and overall survival. However, ADI and RDI did now show any effect on survival.

CONCLUSIONS

Adjuvant chemotherapy with 5-FU plus doxorubicin for 60 weeks after D2-3 dissection induced promising survival duration with acceptable toxicities. Full administration of the planned dosage of the combined drugs is recommendable as opposed to early termination of the chemotherapy in gastric carcinoma.

Preoperative chemoradiotherapy with oral doxifluridine plus low-dose oral leucovorin in unresectable primary rectal cancer

PURPOSE

The use of oral chemotherapeutic agents in chemoradiotherapy provides several advantages. Doxifluridine, an oral 5-FU prodrug, has been shown to be effective in colorectal cancer. We attempted a Phase II trial of preoperative chemoradiotherapy with doxifluridine plus a low-dose oral leucovorin in unresectable primary rectal cancer patients. In this study, toxicity and efficacy were evaluated.

METHODS AND MATERIALS

There were 23 patients with primary unresectable rectal cancer in this trial, 21 of whom were available for analysis. The patients were treated with oral doxifluridine (900 mg/day) plus oral leucovorin (30 mg/day) from days 1 to 35, and pelvic radiation of 45 Gy over 5 weeks. Surgical resection was performed 5-6 weeks after the treatment.

RESULTS

Acute toxicity involved thrombocytopenia, nausea/vomiting, diarrhea, and skin reaction. All were in Grade 1/2, except diarrhea, which was not only the most frequent (7 patients, 33.3%), but also the only toxicity of Grade 3 (2 patients). The clinical tumor response was shown in 5 patients (23.8%) as a complete response and 13 patients (61.9%) as a partial response. A complete resection with negative resection margin was done in 18 patients (85.7%), in 2 of whom a pathologic complete response was shown (9.5%). The overall downstaging rate in the T- and N-stage groupings was 71.4% (15 patients).

CONCLUSION

This study demonstrated the efficacy and low toxicity of chemoradiotherapy with doxifluridine. Currently, a Phase III randomized trial of chemoradiotherapy is ongoing at our institute to compare the therapeutic efficacy of oral 5-FU with respect to i.v. 5-FU in locally advanced and unresectable rectal cancer.

Early postoperative intraperitoneal chemotherapy with mitomycin C, 5-fluorouracil and cisplatin for advanced gastric cancer

OBJECTIVE

The long-term survival of patients who undergo surgery for stage IV gastric cancer is poor, due to metastatic spread of the tumor. Intraperitoneal chemotherapy (IPT) as a possible treatment for peritoneal dissemination has been investigated in a number of different tumors. The aim of this study was to investigate the toxicity and impact of early postoperative IPT on the survival of patients with advanced gastric cancer.

METHODS

Between 1993 and 1997, a total of 91 patients with stage IV gastric cancer who underwent potentially curative or palliative resection received intraperitoneal mitomycin C before closure of the abdominal wound. 5-Fluorouracil and cisplatin were administered intraperitoneally on postoperative days 1-4, and this was repeated at 4-week intervals.

RESULTS

All patients received a median of 3 IPT perfusions. There were 24 (26.4%) postoperative complications and 1 (1.1%) mortality. The most frequent hematologic toxicity (grade 3-4) was leukopenia. The major nonhematologic toxicities (grade 3-4) were emesis and nephrotoxicity. After a median follow-up period of 26 months, 14 patients remain alive without evidence of recurrence, whereas 75 patients died due to recurrence or progression of disease. The median survival period for all 91 patients was 15.4 months. When survival according to the residual tumor was analyzed, median survival was 36.0 months in the R0 (curative resection) group, 20.6 months in the R1 group (margins of resected specimens showing microscopic residual tumor or diameter of each residual tumor less than 3 mm) and 9.0 months in the R2 group (macroscopic residual tumor larger than 3 mm) (p < 0.001).

CONCLUSIONS

IPT was found to be safe, and it appears to improve the prognosis in patients with minimal residual tumors. However, complete cytoreductive surgery is mandatory for achieving the beneficial effect of IPT.

Intravenous 5-fluorouracil versus oral doxifluridine as preoperative concurrent chemoradiation for locally advanced rectal cancer: prospective randomized trials

BACKGROUND

Preoperative radiation treatment with concomitant intravenous infusion of 5-fluorouracil (5-FU) is known to be effective in shrinking and downstaging of tumors. However, chemotherapy has often been limited by its toxicity and poor patient compliance. Oral 5-FU is known to have several advantages over conventional intravenous 5-FU infusion such as lower toxicity and higher quality of life without compromising the efficacy of the treatment. The aim of this study was to compare intravenous 5-FU with oral doxifluridine with respect to tumor response, toxicity and quality of life.

METHODS

Twenty-eight patients with rectal cancer, staged as over T3N1 or T4 by transrectal ultrasonography between July 1997 and December 1998, were included in this study. Intravenous 5-FU (450 mg/m2) and leucovorin (20 mg/m2) were given for five consecutive days during the first and fifth weeks of radiation therapy (50.4 Gy) (n = 14). Oral doxifluridine (700 mg/m2/day) and leucovorin (20 mg/m2) were given daily during radiation treatment (n = 14). Quality of life was scored according to 22 activity items (good, >77; fair, >58; poor, <57). Surgical resection was performed 4 weeks after completion of concurrent chemoradiation treatment. Tumor response was classified into CR (complete remission), PR (partial response; 50% diminution of tumor volume or downstaging ) and NR (no response).

RESULTS

Tumor response was CR 3/14 (21.4%), PR 7/14 (50%) and NR 4/14 (28.6%) in the IV arm versus CR 2/14 (14.2%), PR 6/14 (42.9%) and NR 6/14 (42.9%) in the Oral arm (p = 0.16, 0.23, 0.24), respectively. The quality of life was poor (36.4% versus 33.3%), fair and good (63.6% versus 66.7%) between the IV arm and Oral arm, respectively. Gastrointestinal toxicity was 2/14 (14.3%) in the IV arm versus 5/14 (35.7%) in the Oral arm, respectively. Stomatitis was only observed in the IV arm (1/14, 7.1%). Hematological toxicity was 3/14 (21.4%) in the IV arm versus 4/14 (28.5%) in the Oral arm, respectively. Systemic recurrence during the follow-up periods were 1/14 (7.1%) in the IV arm and 2/14 (14.3%) in the Oral arm, respectively (p = 0.307). One local recurrence was observed in the Oral arm.

CONCLUSION

Even though the results were not entirely reliable owing to the small number of patients enrolled, oral doxifluridine-based chemotherapy as preoperative chemoradiation for advanced rectal cancer did not show any significant advantages over intravenous infusion.

Frameshift mutations at coding mononucleotide repeats of the hRAD50 gene in gastrointestinal carcinomas with microsatellite instability

Microsatellite instability (MSI) and frameshift mutations in genes containing nucleotide repeats have been reported in a subset of colorectal and gastric carcinomas. This study describes the analysis of MSI-positive colorectal (39 cases) and gastric carcinomas (36 cases) for the presence of frameshift mutations of the six genes known to be involved in DNA repair and containing mononucleotide repeats in their coding region. Our mutational study of the 75 MSI-positive tumors revealed frequent mutations in hRAD50 (23 cases, 31%), BLM (16 cases, 21%), and hMSH6 (16 cases, 21%); rare mutations in BRCA1 (1 case, 1%) and ATM (3 cases, 4%); and no mutation in NBS1. In contrast, no frameshift mutation was found in 60 MSI-negative colorectal and gastric carcinomas. The mutation of hRAD50, a gene that is involved in the response to cellular DNA damage and forms a complex with hMRE11 and NBS1, has not been reported previously. Our results suggest that frameshift mutations of hRAD50, BLM, and hMSH6 are selected and play a role in the tumorigenesis of colorectal and gastric carcinomas with MSI. The MSI targeting of the hRAD50 and BLM genes represents an additional link between MSI and DNA repair because alteration of these genes could accelerate defective DNA repair.

Preoperative staging of rectal cancer with MRI: accuracy and clinical usefulness

BACKGROUND

Preoperative staging is essential for planning of optimal therapy for patients with rectal cancer. Recently, magnetic resonance imaging (MRI) is used frequently because of its benefits of clear pelvic image are better than other diagnostic methods. The purpose of this study was to determine accuracy rates and clinical usefulness of MRI in preoperative staging of rectal cancer.

METHODS

Between February, 1997, and December, 1999, 217 patients with histologically proven rectal cancer were staged preoperatively and had surgical resections performed. MRI criteria for depth of invasion was determined by the degree of disruption of the rectal wall. Metastatic perirectal lymph nodes were considered to be present if they showed heterogenous texture, irregular margin, and enlargement (>10 mm).

RESULTS

The accuracy of the MRI for determining depth of invasion was 176/217 (81%) and regional lymph node invasion was 110/217 (63%). In the T stage, accuracy rate of T1 was 3/4 (75%), T2 was 20/37 (54%), T3 was 141/162 (87%), and T4 was 12/14 (86%), respectively. The specificity of lymph node invasion was 45/110 (41%) and the sensitivity was 91/107 (85%). The accuracy rate of regional lymph node involvement was 136/217 (63%). T1 and T2 were overstaged in 1/4 (25%) and 17/37 (46%), respectively, and T3 was understaged in 15/162 (9.2%). The accuracy rate to detect metastatic lateral pelvic lymph node was 4/14 (29%) after lateral pelvic lymph node dissection was done in 14 patients under MRI. The accuracy rate in assessing levator ani muscle tumor involvement was 8/11 (72%).

CONCLUSIONS

MRI showed a good, comparable accuracy rate for determining depth of tumor invasion, compared with transrectal ultrasonography, which still has a low accuracy rate for detecting metastatic lymph node. MRI with endorectal coil may increase the accuracy rate of T1 and T2 lesions. In addition, clear sagittal and coronal sectional pelvic images can give a lot of information about adjacent organ invasion or any invasion of levator ani muscle. MRI can be useful for choosing an appropriate extent of lymph node dissection and type of surgery.

A prospective randomized trial comparing intravenous 5-fluorouracil and oral doxifluridine as postoperative adjuvant treatment for advanced rectal cancer

BACKGROUND

Postoperative adjuvant chemoradiation treatment after curative resection for rectal cancer was needed to reduce recurrence and improve a survival rate. Intravenous 5-fluorouracil (5-FU) and leucovorin has been a mainstay of chemotherapy, but oral 5-FU derivatives have been shown a comparable antitumor activity. Intravenous 5-FU and oral doxifluridine were compared with respect to therapeutic efficacy, drug toxicity, and quality of life.

METHODS

A total of 166 patients were randomized to receive intravenous 5-FU (450 mg/m2/day) or oral doxifluridine (900 mg/m2/day) in combination with leucovorin (20 mg/m2/day) for depth of invasion, nodal status, metastasis (TNM) stage II and III patients between October 1997 and February 1999. Consecutive daily intravenous infusion for 5 days per every month for a total of 12 cycles (IV arm, n = 74) and oral doxifluridine daily for 3 weeks and 1 week rest for a total of 12 cycles (oral arm, n = 92). Drug toxicity and quality of life were observed. Quality of life was scored according to 22 daily activity items (good, > or =71; fair, < 70; poor, < 52).

RESULTS

There was no difference of sex between two groups (IV arm: male/female = 45/29, oral arm: male/female = 59/33). The mean age was 52.3 vs. 59.5, respectively. There was also no difference of TNM stage distribution and type of operation between groups (P>.05). Mean numbers of chemotherapy cycles were 6.5+/-3.7 (IV arm) vs. 7.2+/-4.3 (oral arm), respectively. The rate of recurrence was 9/74 (12.1%) in the IV arm and 6/92 (6.5 %) in the oral arm, respectively (P = .937). Local recurrence was 2/74 (stage III; 2.7%) in the IV arm and 1/92 (stage II; 1.1%) in the oral arm, respectively. Systemic recurrence was 7/74 (stage III; 9.4%) in the IV arm and 5/92 (stage III; 5.4%) in the oral arm, respectively. The most common site of systemic recurrence was the liver. Toxicity profile was as follows: leukopenia (30/74 vs. 17/92) and alopecia (21/74 vs. 13/92) were statistically more common in the IV arm. Diarrhea was more common in the oral arm. Poor quality of life score between two groups was observed at 1 month (23.9% vs. 13%) and 2 months (15.8% vs. 3.7%) after chemotherapy. Good quality of life score was observed at 1 month (19.5% vs. 49%) and 2 months (47% vs. 72%), respectively (P<.05).

CONCLUSIONS

Oral doxifluridine with leucovorin shows a comparable therapeutic efficacy to intravenous 5-FU regimen with high quality of life as postoperative adjuvant therapy. The oral regimen also can be safely given with appropriate toxicity and tolerability.

Restorative proctocolectomy: operative safety and functional outcomes

Restorative proctocolectomy (total proctocolectomy and ileal J pouch anal anastomosis) has been accepted as the operation of choice in the setting of chronic ulcerative colitis and familial adenomatous polyposis. The purpose of this study was to assess operative safety and functional outcome after restorative proctocolectomy. A total of sixteen patients underwent surgery between January 1996 and December 1999. Hand sewn anastomosis with diverting ileostomy was performed in 9 patients and double stapled anastomosis in 7 patients. The underlying disease was ulcerative colitis in 9 cases and familial adenomatous polyposis in 7. Postoperative complications developed in 8 cases (50%), and intestinal obstruction was found in 4 cases (2 cases were operated upon). Anastomosis related complications were stenosis (n=2), leak (n=1) and perianal abscess (n=1). All patients were followed up at the outpatient clinic using questionnaires, with a mean follow up period of 19.9 months. The frequency of bowel movement was 8.2 per day in hand sewn anastomosis (HS), and 12 per day in double stapled anastomosis (DS) 3 months after surgery (period 1). This frequency decreased to 5.5 per day in HS, and 4.6 per day in DS after one year (period 2). Day and night continence was shown in 12/15, and 5/15, respectively in period 1, but improved to 10/11, and 10/11, respectively in period 2. Night time incontinence was noted in 10 of 15 patients in period 1 (seepage 3/15, soiling 7/15). The need to take anti-diarrheal medication, and to use a pad was noted in 2/15, and 10/15, respectively in period 1, but no patient took antidiarrheal medication or wore a protective pad in period 2. Postoperative urinary function was satisfactory in 13/14 patients. Postoperative sexual function was analyzed in a total of 8 patients, who showed good erection (5/5), ejaculation (5/5) and satisfactory sexual life (5/5). In females, 3 patients showed a satisfactory sexual life. In conclusion, restorative proctocolectomy for chronic ulcerative colitis and familial adenomatous polyposis can be performed safely with excellent functional outcomes, including bowel movement, urinary and sexual functions one year after surgery.

Tissue urokinase-type plasminogen activator receptor levels in breast cancer

Cancer invasion is induced by several proteolytic enzyme systems associated with the destruction of basement membrane and extracellular matrix. Urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor-1 (PAI-1) have been reported as prognostic factors in breast cancer patients and plasminogen activation is regulated by various factors such as uPAR and growth factors. Thus, we examined the tissue levels of urokinase-type plasminogen activator receptor (uPAR) in breast cancer patients. Tissue uPAR levels were measured by ELISA assay in 268 breast cancer patients. The median and mean values of tissue uPAR level in breast cancer were 3.5 ng/mg cytosol protein and 4.8+/-3.6 ng/mg cytosol protein, respectively. Tissue uPAR level was the highest in T1 stage, but there was no statistical significance between the T stages (p>0.05), nor in nodal stage, in the value of uPAR according to progression. And the value of uPAR expression was not associated with estrogen and progesterone receptor status, number of involved node and percent of node involvement. In TNM stage, tissue uPAR levels were higher in patients with stage I-II than in patients with stage III-IV (p=0.027). In univariate analysis, nodal factor (p=0.002) and TNM stage (p=0.0004) were significant. But, multivariate analysis showed that TNM stage was the only significant prognostic factor (p=0.0002). These results suggest that uPAR is mainly associated with initial tumor invasion and other factors might be involved in later stages of cancer progression.