Morbidity and Mortality of Laparoscopic Versus Open D2 Distal Gastrectomy for Advanced Gastric Cancer: A Randomized Controlled Trial

Beyond precision surgery: Molecularly motivated precision care for gastric cancer

Gastric cancer is one of the leading causes of cancer-related deaths worldwide. Despite the high disease prevalence, gastric cancer research has not gained much attention. Recently, genome-scale technology has made it possible to explore the characteristics of gastric cancer at the molecular level. Accordingly, gastric cancer can be classified into molecular subtypes that convey more detailed information of tumor than histopathological characteristics, and these subtypes are associated with clinical outcomes. Furthermore, this molecular knowledge helps to identify new actionable targets and develop novel therapeutic strategies. To advance the concept of precision patient care in the clinic, patient-derived xenograft (PDX) models have recently been developed. PDX models not only represent histology and genomic features, but also predict responsiveness to investigational drugs in patient tumors. Molecularly curated PDX cohorts will be instrumental in hypothesis generation, biomarker discovery, and drug screening and testing in proof-of-concept preclinical trials for precision therapy. In the era of precision medicine, molecularly tailored therapeutic strategies should be individualized for cancer patients. To improve the overall clinical outcome, a multimodal approach is indispensable for advanced cancer patients. Careful, oncological principle-based surgery, combined with a molecularly guided multidisciplinary approach, will open new horizons in surgical oncology.

Notes on laparoscopic gastrointestinal surgery-current status from clinical studies of minimally invasive surgery for gastric cancer

To establish high-quality evidence of laparoscopic gastrectomy (LAG) in the field of gastric cancer treatments, large-scale, prospective randomized controlled trials have been performed in Japan, Korea and China. Furthermore, as advanced laparoscopic techniques have been developed, prospective clinical studies are being performed with regard to laparoscopy-assisted total gastrectomy and robotic gastrectomy. This review summarizes the current status of minimally invasive surgeries for gastric cancer based on the latest ongoing clinical trials.

Differences in the multimodal treatment of gastric cancer: East versus west

There has been a great deal of interest about varying treatment paradigms of gastric cancer in Eastern and Western countries. Differences in tumor biology, screening initiatives, surgical approach, extent of lymphadenectomy, and neoadjuvant versus adjuvant chemotherapy regimens have been studied and documented in the literature. The purpose of this review is to give an updated report on the current status and management differences in the treatment of gastric cancer between Eastern and Western countries.

Timing of initiation of adjuvant chemotherapy for gastric cancer: A case-matched comparison study of laparoscopic vs. open surgery

BACKGROUND

Laparoscopic gastrectomy (LG) is reported to be associated with faster recovery than open gastrectomy (OG); however, the influence of the surgical approach on initiation timing of adjuvant chemotherapy (AC) remains unclear.

METHODS

This was a single-institutional retrospective observational study. Patients with pathological stage II/III gastric cancer undergoing LG with D2 lymphadenectomy (LG group: n = 74) were matched 1:1 with patients selected from 214 similar patients undergoing OG (OG group: n = 74), identically matching gender, age, pathological stage, and type of gastrectomy, and comparing AC initiation timing between the two groups. Factors associated with delayed initiation of AC were investigated in a multivariable analysis.

RESULTS

AC was performed in 86.5% (LG) and 83.8% (OG) of patients (p = 0.64). The median time interval before AC was significantly shorter in the LG vs. OG group (5.7 vs. 6.6 weeks, respectively, p < 0.001), and significantly more patients received AC within 6 weeks (60.8% vs. 27.0%, p < 0.001). Independent factors associated with delayed initiation of AC (>6 weeks) were: morbidity (≥grade 3a; odds ratio (OR): 16.1, 95% confidence interval (CI): 1.86-143), open surgery (OR: 5.17, 95% CI: 2.50-13.1), and postoperative weight loss ≥ 8% (OR: 2.47, 95% CI: 1.07-5.71).

CONCLUSIONS

LG may be associated with shorter intervals before AC. Postoperative morbidity should be reduced as much as possible.

Safety and feasibility of minimally invasive gastrectomy during the early introduction in the Netherlands: short-term oncological outcomes comparable to open gastrectomy

BACKGROUND

Minimally invasive techniques for gastric cancer surgery have recently been introduced in the Netherlands, based on a proctoring program. The aim of this population-based cohort study was to evaluate the short-term oncological outcomes of minimally invasive gastrectomy (MIG) during its introduction in the Netherlands.

METHODS

The Netherlands Cancer Registry identified all patients with gastric adenocarcinoma who underwent gastrectomy with curative intent between 2010 and 2014. Multivariable analysis was performed to compare MIG and open gastrectomy (OG) on lymph node yield (≥15), R0 resection rate, and 1-year overall survival. The pooled learning curve per center of MIG was evaluated by groups of five subsequent procedures.

RESULTS

Between 2010 and 2014, a total of 277 (14%) patients underwent MIG and 1633 (86%) patients underwent OG. During this period, the use of MIG and neoadjuvant chemotherapy increased from 4% to 39% (p < 0.001) and from 47% to 62% (p < 0.001), respectively. The median lymph node yield increased from 12 to 20 (p < 0.001), and the R0 resection rate remained stable, from 86% to 91% (p = 0.080). MIG and OG had a comparable lymph node yield (OR, 1.01; 95% CI, 0.75-1.36), R0 resection rate (OR, 0.86; 95% CI, 0.54-1.37), and 1-year overall survival (HR, 0.99; 95% CI, 0.75-1.32). A pooled learning curve of ten procedures was demonstrated for MIG, after which the conversion rate (13%-2%; p = 0.001) and lymph node yield were at a desired level (18-21; p = 0.045).

CONCLUSION

With a proctoring program, the introduction of minimally invasive gastrectomy in Western countries is feasible and can be performed safely.

Can Robotic Gastrectomy Surpass Laparoscopic Gastrectomy by Acquiring Long-Term Experience? A Propensity Score Analysis of a 7-Year Experience at a Single Institution

PURPOSE

It is hypothesized that robotic gastrectomy may surpass laparoscopic gastrectomy after the operators acquire long-term experience and skills in the manipulation of robotic arms. This study aimed to evaluate the long-term learning curve of robotic distal gastrectomy (RDG) for gastric cancer compared with laparoscopic distal gastrectomy (LDG).

MATERIALS AND METHODS

From October 2008 to December 2015, patients who underwent LDG (n=809) were matched to patients who underwent RDG (n=232) at a 1:1 ratio, by using a propensity score matching method after stratification for the operative year. The surgical outcomes, such as trends of operative time, blood loss, and complication rate, were compared between the two groups.

RESULTS

The RDG group showed a longer operative time (171.3 minutes vs. 147.6 minutes, P<0.001) but less estimated blood loss (77.6 ml vs. 116.6 ml, P<0.001). The complication rate and postoperative recovery did not differ between the two groups. The RDG group showed a longer operative time and similar estimated blood loss compared with the LDG group after 5 years of experience (operative time: 159.2 minutes vs. 136.0 minutes in 2015, P=0.003; estimated blood loss: 72.9 ml vs. 78.1 ml in 2015, P=0.793).

CONCLUSIONS

In terms of short-term surgical outcomes, RDG may not surpass LDG after a long-term experience with the technique.

Postoperative Complications of Laparoscopic Total Gastrectomy versus Open Total Gastrectomy for Gastric Cancer in a Meta-Analysis of High-Quality Case-Controlled Studies

Background. Some meta-analyses of case-controlled studies (CCSs) have shown that laparoscopic or laparoscopy-assisted total gastrectomy (LTG) had some short-term advantages over open total gastrectomy (OTG). However, postoperative complications differed somewhat among the meta-analyses, and some CCSs included in the meta-analyses had mismatched factors between LTG and OTG. Methods. CCSs comparing postoperative complications between LTG and OTG were identified in PubMed and Embase. Studies matched for patients' status, tumor stage, and the extents of lymph-node dissection were included. Outcomes of interest, such as anastomotic, other intra-abdominal, wound, and pulmonary complications, were evaluated in a meta-analysis performed using Review Manager version 5.3 software. Result. This meta-analysis included a total of 2,560 patients (LTG, 1,073 patients; OTG, 1,487 patients) from 15 CCSs. Wound complications were significantly less frequent in LTG than in OTG (n = 2,430; odds ratio [OR] 0.30, 95% confidence interval [CI] 0.29-0.85, P = 0.01, I2 = 0%, and OR 0.46, 95% CI 0.17-0.52, P < 0.0001, I2 = 0%). However, the incidence of anastomotic complications was slightly but not significantly higher in LTG than in OTG (n = 2,560; OR 1.44, 95% CI 0.96-2.16, P = 0.08, I2 = 0%). Conclusion. LTG was associated with a lower incidence of wound-related postoperative complications than was OTG in this meta-analysis of CCSs; however, some concern remains about anastomotic problems associated with LTG.

An update in the nonendoscopic treatment of gastric cancer

PURPOSE OF REVIEW

This article reviews the recent seminal studies in esophagogastric cancer.

RECENT FINDINGS

Regular low aspirin use may reduce the risk of esophagogastric cancer. Laparoscopic resection of locally advanced gastric cancer appears equivalent to open resection. There is no survival benefit for the addition of postoperative radiation therapy to adjuvant chemotherapy after primary gastric cancer resection. For tumors of the esophagus and gastroesophageal junction, the combination of preoperative radiation therapy with concurrent chemotherapy may be required to ensure achievement of a negative surgical margin and to reduce local tumor recurrence. Epirubicin may not add benefit to fluorinated pyrimidine and platinum-based chemotherapy, either in the preoperative setting or in the treatment of metastatic disease. The Her2-targeted agents lapatinib and trastuzumab emtansine failed to improve outcome when either added to or compared with chemotherapy. Immune checkpoint inhibition appears to be active in metastatic gastric cancer.

SUMMARY

Recent studies in esophagogastric cancer help clarify the role of radiation therapy in surgical management, as well as the role of chemotherapeutic and targeted agents.

Morbidity and Mortality After Gastrectomy: Identification of Modifiable Risk Factors

BACKGROUND

Morbidity after gastrectomy remains high. The potentially modifiable risk factors have not been well described. This study considers a series of potentially modifiable patient-specific and perioperative characteristics that could be considered to reduce morbidity and mortality after gastrectomy.

METHODS

This retrospective cohort study includes adults in the ACS NSQIP PUF dataset who underwent gastrectomy between 2011 and 2013. Sequential multivariable models were used to estimate effects of clinical covariates on study outcomes including morbidity, mortality, readmission, and reoperation.

RESULTS

Three thousand six hundred and seventy-eight patients underwent gastrectomy. A majority of patients had distal gastrectomy (N = 2,799, 76.1 %) and had resection for malignancy (N = 2,316, 63.0 %). Seven hundred and ninety-eight patients (21.7 %) experienced a major complication. Reoperation was required in 290 patients (7.9 %). Thirty-day mortality was 5.2 %. Age (OR = 1.01, 95 % CI = 1.01-1.02, p = 0.001), preoperative malnutrition (OR = 1.65, 95 % CI = 1.35-2.02, p < 0.001), total gastrectomy (OR = 1.63, 95 % CI = 1.31-2.03, p < 0.001), benign indication for resection (OR = 1.60, 95 % CI = 1.29-1.97, p < 0.001), blood transfusion (OR = 2.57, 95 % CI = 2.10-3.13, p < 0.001), and intraoperative placement of a feeding tubes (OR = 1.28, 95 % CI = 1.00-1.62, p = 0.047) were independently associated with increased risk of morbidity. Association between tobacco use and morbidity was statistically marginal (OR = 1.23, 95 % CI = 0.99-1.53, p = 0.064). All-cause postoperative morbidity had significant associations with reoperation, readmission, and mortality (all p < 0.001).

CONCLUSIONS

Mitigation of perioperative risk factors including smoking and malnutrition as well as identified operative considerations may improve outcomes after gastrectomy. Postoperative morbidity has the strongest association with other measures of poor outcome: reoperation, readmission, and mortality.

Whole-exome sequencing to identify somatic mutations in peritoneal metastatic gastric adenocarcinoma: A preliminary study

Peritoneal metastasis occurs in more than half of patients with unresectable or recurrent gastric cancer and is associated with the worst prognosis. The associated genomic events and pathogenesis remain ambiguous. The aim of the present study was to characterize the mutation spectrum of gastric cancer with peritoneal metastasis and provide a basis for the identification of new biomarkers and treatment targets. Matched pairs of normal gastric mucosa and peritoneal tissue and matched pairs of primary tumor and peritoneal metastasis were collected from one patient for whole-exome sequencing (WES); Sanger sequencing was employed to confirm the somatic mutations. G>A and C>T mutations were the two most frequent transversions among the somatic mutations. We confirmed 48somatic mutations in the primary site and 49 in the peritoneal site. Additionally, 25 non-synonymous somatic variations (single-nucleotide variants, SNVs) and 2 somatic insertions/deletions (INDELs) were confirmed in the primary tumor, and 30 SNVs and 5 INDELs were verified in the peritoneal metastasis. Approximately 59% of the somatic mutations were shared between the primary and metastatic site. Five genes (TP53, BAI1, THSD1, ARID2, and KIAA2022) verified in our study were also mutated at a frequency greater than 5%in the COSMIC database. We also identified 9genes (ERBB4, ZNF721, NT5E, PDE10A, CA1, NUMB, NBN, ZFYVE16, and NCAM1) that were only mutated in metastasis and are expected to become treatment targets. In conclusion, we observed that the majority of the somatic mutations in the primary site persisted in metastasis, whereas several single-nucleotide polymorphisms occurred de novo at the second site.

A Step-Wise Approach to Total Laparoscopic Gastrectomy with Jejunal Pouch Reconstruction: How and Why We Do It

Laparoscopic gastrectomy (LG) is a safe alternative compared to open gastrectomy for cancer. To increase the uptake of minimally invasive approaches and facilitate their analysis and improvement a stepwise approach is warranted. This study describes our technique and experiences total laparoscopic gastrectomy (TLG) with jejunal pouch reconstruction for gastric cancer. Technical modifications throughout the years were described. In patients with anastomotic leakage, the CT-scan and reoperation report were reviewed to identify the location and cause of the leak. A total of 47 patients who underwent laparoscopic total gastrectomy with extracorporeal jejunal pouch reconstruction and stapled circular esophagojejunostomy from May 2007 to August 2015 were prospectively analyzed. A stepwise approach of 10 steps was designed based on video and case analysis. Median operation time was 301 (148-454) minutes and median blood loss was 300 (30-900) milliliters. Anastomotic leakage occurred in six (12.8 %) patients; additionally, one (2.12 %) jejunal-pouch staple line leak was identified. An important modification in our technique was a purse-string suture around the anvil of the circular stapler to prevent esophageal mucosa to slip away. After this modification, the leakage rate was reduced to 7 % in the last 15 procedures. In conclusion, TLG with jejunal pouch reconstruction is a feasible procedure in a selected group of patients. Our stepwise approach and technique may help surgeons to introduce jejunal pouch reconstruction during laparoscopic gastrectomy in their center.