Meta-analysis of pylorus-preserving gastrectomy for middle-third early gastric cancer

A Comparative Study of Postoperative Complications Associated with Distal Gastrectomy and Pylorus-Preserving Gastrectomy among Gastric Cancer Patients Based on Nationwide Survey Data and Propensity Score Weighting

BACKGROUND/OBJECTIVE

This study aimed to compare complication rates between pylorus-preserving gastrectomy (PPG) and distal gastrectomy (DG) using Korean nationwide survey data and propensity score weighting (PSW). PPG preserves gastric function but may lead to more postoperative complications than DG.

METHODS AND RESULTS

We analyzed 9424 gastric cancer patients who underwent either DG (n = 9183) or PPG (n = 241). PSW balanced variables such as age, sex, TNM stage, comorbidities, ASA score, and surgical approach. Before PSW, 87.8% of DG patients and 87.1% of PPG patients had no complications (p = 0.053). Severe complications (Clavien-Dindo IIIa or higher) were more frequent in PPG (6.6%) than in DG (3.8%) (p = 0.039). After PSW, overall complication rates (p = 0.960) and severe complication rates (p = 0.574) were similar between groups. Incidence rates of anastomotic stricture and leakage were higher in PPG (2.9% and 1.7%) compared to DG (0.6% and 0.5%) (p = 0.001 and 0.036) before PSW, but these differences were not significant after PSW (p = 0.999 and 0.123).

CONCLUSION

The PSW-adjusted analysis indicates no significant difference in overall and severe complication rates between PPG and DG in gastric cancer patients.

A comparison between pylorus-preserving and distal gastrectomy in surgical safety and functional benefit with gastric cancer: a systematic review and meta-analysis

BACKGROUND

Due to better functional outcomes, pylorus-preserving gastrectomy (PPG) has been widely applied for early gastric cancer (EGC) patients as an alternative to distal gastrectomy (DG). However, controversies still persist regarding the surgical efficacy and oncological safety of PPG.

METHODS

Original studies comparing PPG and DG for EGC were searched in PubMed, Embase, and the Cochrane Register of Controlled Trials up to December 2019. The weight mean difference, standardized mean difference, or odds risk was used to calculate the short-term and long-term outcomes between the two groups.

RESULTS

Twenty-one comparative studies comprising 4871 patients (1955 in the PPG group and 2916 in the DG group) were enrolled in this systematic review and meta-analysis. PPG showed longer hospital day, decreased harvested lymph nodes, and more delayed gastric emptying. However, PPG had the benefits of lower incidence of anastomosis leakage, early dumping syndrome, gastritis and bile reflux, and better recovery of total protein, albumin, hemoglobin, and weight. No difference was found in operative time, blood loss, and overall complications. Moreover, the long-term survival and recurrence rate were similar in two groups.

CONCLUSION

Owing to the non-inferiority of surgery and oncology outcomes and the superiority of function outcomes in PPG, we revealed that PPG can be clinically applicable instead of DG in EGC. However, more high-quality comparative studies and randomized clinical trials would be required for further confirmation.

Laparoscopy-assisted pylorus-preserving gastrectomy for early gastric cancer: A retrospective study of long-term functional outcomes and quality of life

BACKGROUND

Laparoscopy-assisted pylorus-preserving gastrectomy (LAPPG) was known to have benefits of function-preserving surgery compared to laparoscopy-assisted distal gastrectomy (LADG). However, in clinical settings, delayed gastric emptying and esophageal reflux following LAPPG can be serious issues, making surgeons reluctant to perform LAPPG. It is unclear that LAPPG had better long-term functional outcomes and quality of life compared to LADG.

AIM

To evaluate the long-term functional outcomes and patient-reported quality of life of LAPPG compared to those of LADG.

METHODS

We reviewed the clinicopathological data of 195 patients who underwent LADG with Billroth II anastomosis and 101 patients who underwent LAPPG for cT1N0 gastric cancer in the middle third of the stomach between 2012 and 2015. Postoperative complications, nutritional parameters, and survey results of the European Organization for Research and Treatment of Cancer Questionnaire C30 and STO22 questionnaire were compared between the two groups.

RESULTS

The serum hemoglobin level was significantly higher in the LAPPG group than in the LADG group (P < 0.001). In the endoscopic findings, incidence of bile reflux was lower (P < 0.001); however, the incidence of residual food was higher in the LAPPG group than in the LADG group (P < 0.001). Regarding the quality of life score, the LAPPG group had a better physical functioning score (86.7 vs 90.0, P = 0.032) but also greater pain and reflux when compared to the LADG group [8.3 vs 16.7 in pain, 11.1 (interquartile range, 0, 22.2) vs 11.1 (interquartile range, 11.1, 33.3) in reflux, P = 0.034 and 0.001, respectively].

CONCLUSION

LAPPG is beneficial to recovery of anemia and to bile reflux, however, it might be unfavorable in terms of pain and reflux symptoms compared to LADG with Billroth II anastomosis.

Perioperative outcomes of laparoscopy-assisted pylorus and vagus nerve-preserving gastrectomy and distal gastrectomy for middle-third early gastric cancer

AIM

To compare the surgical safety, postoperative compli-cations and hospitalization expenses of laparoscopy-assisted pylorus and vagus nerve-preserving gastrectomy (LAPPG) and distal gastrectomy (LADG) in order to evaluate the feasibility of LAPPG in the treatment of middle-third early gastric cancer.

METHODS

The clinical and pathological data, surgical procedure, postoperative outcomes and hospitalization expenses of 112 patients with middle-third early gastric cancer treated from June 2016 to August 2017 at Department of Gastrointestinal Surgery of Renji Hospital were analyzed retrospectively. Forty-six patients received LAPPG, and 66 cases underwent LADG.

RESULTS

There were no significant differences between the two groups in age, sex, BMI, tumor differentiation, operative time, estimated blood loss, tumor diameter, resected lymph nodes, or metastatic lymph nodes (P > 0.05). Proximal and distal resection margins were significantly shorter in the LAPPG group than in the LADG group (P < 0.05). For postoperative outcomes, there were no significant differences in hospital stay, time to first flatus, time to gastric tube removal, time to first ambulation, time to first fluid diet, or postoperative complications (≥Dindo grade Ⅱ) (P > 0.05). Hospitalization expense of LAPPG was significantly lower than that of LADG [4.6 ± 0.5 vs 5.3 ± 0.4 (ten thousand yuan), P = 0.004].

CONCLUSION

On the premise of oncologic safety and efficacy, LAPPG is a cost-effective and feasible treatment for middle-third early gastric cancer.

Knockdown of Cbp/P300-interacting transactivator with Glu/Asp-rich carboxy-terminal domain 2 inhibits cell division and increases apoptosis in gastric cancer

BACKGROUND

Cbp/P300-interacting transactivator with Glu/Asp-rich carboxy-terminal domain 2 (CITED2) is a pleiotropic protein associated with numerous cell functions, including transcription and differentiation. The role of CITED2 has been investigated in a number of malignancies; however, the roles of this protein in gastric cancers remain unclear. Therefore, we determined the role of CITED2 in gastric cancers.

MATERIALS AND METHODS

Gastric cancer cell lines (MKN74, MKN28, 7901, and AGS) were used to assess CITED2 transcript levels. Messenger RNA levels were determined using quantitative polymerase chain reaction. Lentiviral vectors containing CITED2 small interfering RNA were used to knockdown CITED2 expression. Cell proliferation was assessed with fluorescent imaging and 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide assays. Apoptosis and cell cycle stages were assessed through flow cytometry, and formation of colonies was determined using a fluorescent microscope.

RESULTS

All cell lines tested in this study expressed CITED2. The cell line expressing the highest levels of CITED2 (MKN74) showed significant knockdown of endogenous CITED2 expression on lentiviral infection. Cell proliferation was shown to be lower in CITED2 knockdown MKN74 cells. G1/S-phase cell cycle arrest was observed on silencing of CITED2 in MKN74 cells. A significant increase in apoptosis was observed on CITED2 knock down in MKN74 cells, while colony forming ability was significantly inhibited after knock down of CITED2.

CONCLUSIONS

CITED2 supports gastric cancer cell colony formation and proliferation while inhibiting apoptosis making it a potential gene therapy target for gastric cancer.

Pylorus-Preserving Gastrectomy for Gastric Cancer

Pylorus-preserving gastrectomy (PPG) is a function-preserving surgery for the treatment of early gastric cancer (EGC), aiming to decrease the complication rate and improve postoperative quality of life. According to the Japanese gastric cancer treatment guidelines, PPG can be performed for cT1N0M0 gastric cancer located in the middle-third of the stomach, at least 4.0 cm away from the pylorus. Although the length of the antral cuff gradually increased, from 1.5 cm during the initial use of the procedure to 3.0 cm currently, its optimal length still remains unclear. Standard procedures for the preservation of pyloric function, infra-pyloric vessels, and hepatic branch of the vagus nerve, make PPG technically more difficult and raise concerns about incomplete lymph node dissection. The short- and long-term oncological and survival outcomes of PPG were comparable to those for distal gastrectomy, but with several advantages such as a lower incidence of dumping syndrome, bile reflux, and gallstone formation, and improved nutritional status. Gastric stasis, a typical complication of PPG, can be effectively treated by balloon dilatation and stent insertion. Robot-assisted pylorus-preserving gastrectomy is feasible for EGC in the middle-third of the stomach in terms of the short-term clinical outcome. However, any benefits over laparoscopy-assisted PPG (LAPPG) from the patient's perspective have not yet been proven. An ongoing Korean multicenter randomized controlled trial (KLASS-04), which compares LAPPG and laparoscopy-assisted distal gastrectomy for EGC in the middle-third of the stomach, may provide more clear evidence about the advantages and oncologic safety of PPG.