Transectional gastrectomy: an old but renewed concept for early gastric cancer

Pylorus-preserving gastrectomy for early gastric cancer

Pylorus-preserving gastrectomy (PPG) has been widely accepted as a function-preserving gastrectomy for middle-third early gastric cancer (EGC) with a distal tumor border at least 4 cm proximal to the pylorus. The procedure essentially preserves the function of the pyloric sphincter, which requires to preserve the upper third of the stomach and a pyloric cuff at least 2.5 cm. The suprapyloric and infrapyloric vessels are usually preserved, as are the hepatic and pyloric branches of the vagus nerve. Compared with distal gastrectomy, PPG has significant advantages in preventing dumping syndrome, body weight loss and bile reflux gastritis. The postoperative complications after PPG have reached an acceptable level. PPG can be considered a safe, effective, and superior choice in EGC, and is expected to be extensively performed in the future.

Long‑term survival prognosis of function‑preserving curative gastrectomy for early gastric cancer

Segmental gastrectomy, mini-distal gastrectomy and local resection of the stomach are function-preserving curative gastrectomies (FPGs), which are used to treat gastric cancer in specialized centers. These surgical options are less invasive and can alleviate postgastrectomy symptoms more than standard gastrectomy; however, their association with prognosis remains to be fully elucidated. The present study aimed to compare the survival prognosis of patients diagnosed as node-negative by sentinel node biopsy (SNB) treated via FPG with reduced lymph node dissection with that of patients who underwent guideline gastrectomy (GL). This retrospective study was conducted between April 1999 and March 2016. The inclusion criteria were a diagnosis of gastric cancer type 0, of ≤5 cm, located in L or M areas, and pT1N0. Patients who underwent distal gastrectomy and pylorus-preserving gastrectomy were included as controls in the GL group. Among the 146 and 300 patients in the FPG and GL groups, respectively, only 1 patient in the GL group experienced recurrence. The overall survival (OS) of the FPG group was 96.6% at 5 years and 92.5% at 10 years, which was significantly higher than that of the GL group (P<0.05). In addition, the cumulative incidence of non-cancer-related deaths, especially pulmonary diseases, was lower in the FPG group than that in the GL group (P<0.05). Notably, the OS and non-cancer death rate in the FPG group remained significantly better after propensity score-matching analysis. In conclusion, for early gastric cancer located in M or L areas, patients treated via FPG guided by SNB have a better prognosis and fewer deaths caused by respiratory disease than those treated via GL. The present clinical trial was registered under the following trial registration numbers: UMIN000010154 (2013/3/4), UMIN000023828 (2016/8/29), jRCTs041180006 (2018/10/9).

nPTD classification: an updated classification of gastric cancer location for function preserving gastrectomy based on physiological lymphatic flow

Background

The correlation between tumor location and lymphatic flow distribution in gastric cancer has been previously reported, and PTD (Proximal – Transitional – Distal) classification was proposed. Our group updated and developed the nPTD classification.

Method

We retrospectively studied gastric cancer patients who underwent the dye method sentinel node biopsy from 1993 to 2020. The inclusion criteria were a single lesion type 0 cancer of ≤5 cm in the long axis, clinically node-negative, and invasion within the proper muscle layer pathologically. In this study, the distribution of dyed lymphatic flow was evaluated for each occupied area of the tumor.

Results

We included 416 patients in this study. The tumors located in the watershed of the right and left gastroepiploic arteries near greater curvature had extensive lymphatic flow; therefore, a newly circular region with a diameter of 5 cm is set on the watershed of the greater curvature between P and T zone as the ‘n’ zone. In addition, for cancers located in the lesser P curvature, lymphatic flow to the greater curvature was not observed. Therefore, the P zone was divided into two: the lesser curvature side (PL) and the greater curvature side (PG).

Conclusions

The advantage of the nPTD classification is that it provides not only proper nodal dissection but also adequate function-preserving gastrectomy. If the tumor is localized within the PL, the proximal gastrectomy resection area can be further reduced. In contrast, for cancers located in the ‘n’ zone, near-total gastrectomy is required because of the extensive lymphatic flow.

The Incidence and Risk Factors for Metachronous Gastric Cancer in the Remnant Stomach after Gastric Cancer Surgery

Background/Aims

Less invasive surgical treatment is performed in East Asia to preserve postoperative digestive function and reduce complications such as postgastrectomy syndromes, but there is an issue of metachronous gastric cancer (GC) in the remaining stomach. This study aimed to analyze the incidence of metachronous GC and its risk factors in patients who had undergone partial gastrectomy.

Methods

A total of 3,045 GC patients who had undergone curative gastric partial resection at Seoul National University Bundang Hospital were enrolled and analyzed retrospectively for risk factors, including age, sex, smoking, alcohol, Helicobacterpylori status, family history of GC, histological type, and surgical method.

Results

Metachronous GC in the remaining stomach occurred in 35 of the 3,045 patients (1.1%) 23 in the distal gastrectomy group (18 with Billroth-I anastomosis, five with Billroth-II anastomosis), seven in the proximal gastrectomy (PG) group, and five in the pylorus-preserving gastrectomy (PPG) group. Univariate and multivariate Cox regression analyses showed that age ≥60 years (p=0.005) and surgical method used (PG or PPG, p<0.001) were related risk factors for metachronous GC, while male sex and intestinal type histology were potential risk factors.

Conclusions

Metachronous GC was shown to be related to older age and the surgical method used (PG or PPG). Regular and careful follow-up with endoscopy should be performed in the case of gastric partial resection, especially in patients with male sex and intestinal type histology as well as those aged ≥60 years undergoing the PG or PPG surgical method.

The incidences of metachronous multiple gastric cancer after various types of gastrectomy: analysis of data from a nationwide Japanese survey

BACKGROUND

The incidence of metachronous multiple gastric cancer (MMGC) after gastrectomy remains unclear. This study evaluated the incidences of MMGC according to specific gastrectomy types, including pylorus-preserving gastrectomy (PPG), proximal gastrectomy (PG), and function-preserving gastrectomy (FPG), which was categorized as segmental gastrectomy and local resection.

METHODS

We conducted a questionnaire survey of the Japanese Society for Gastro-Surgical Pathophysiology members, who were asked to report their institutional numbers of radical gastrectomy cases for cancer between 2003 and 2012. The cases were categorized according to whether the remnant stomach's status was followed for > 5 years, confirmation of MMGC, time to diagnosis, and treatment for MMGC. We calculated the "precise incidence" of MMGC by dividing the number of MMGC cases by the number of cases in which the status of remnant stomach was followed up for > 5 years.

RESULTS

The responses identified 33,731 cases of gastrectomy. The precise incidences of MMGC were 2.35% after distal gastrectomy (DG), 3.01% after PPG, 6.28% after PG (p < 0.001), and 8.21% after FPG (p < 0.001). A substantial proportion of MMGCs (36.4%) was found at 5 years after the initial surgery. The rates of MMGC treatment using endoscopic submucosal dissection were 31% after DG, 28.6% after PPG, 50.8% after PG (p < 0.001), and 67.9% after FPG (p < 0.001).

CONCLUSIONS

The incidence of MMGC was 2.4% after DG, and higher incidences were observed for larger stomach remnants. However, the proportion of cases in which MMGC could be treated using endoscopic submucosal dissection was significantly higher after PG and FPG than after DG.

Laparoscopic sentinel node navigation surgery for early gastric cancer

Currently, the most accurate method for identifying lymph node metastasis is intraoperative diagnosis by sentinel node (SN) biopsy. Based on the SNNS study-a recent large-scale, nationwide, multicenter prospective study-the SN concept seems to be scientifically valid in patients with early gastric cancer. SN biopsy is a multistep technique consisted of six essential elements: indication, the selection of a tracer, a proper tracer injection method, the objective detection of SNs, a reliable biopsy technique, and the precise detection of nodal metastasis. For SN biopsy of gastric cancer, these elements have been validated as follows: the indication should be limited to clinical T1 less than 4 cm in diameter; combination mapping with radioactive colloid and blue dye is used as the standard; and endoscopic submucosal injection is the standard tracer injection. Detection of SNs and a reliable biopsy technique are enabled by adaptation of lymphatic basin dissection, a proper biopsy technique for gastric cancer. Lymphatic basin dissection is a selective lymphadenectomy procedure for dissecting basins en bloc, collecting lymph nodes and lymphatic vessels stained with dye. Lymphatic basin dissection is superior to the ordinary pick-up method, not only for minimizing the rate of missed SNs, but also in terms of oncological safety as it complements an intraoperative frozen section diagnosis by serving as a backup dissection. Moreover, indocyanine green (ICG) fluorescence mapping has been developed in recent years. ICG fluorescence mapping is superior because of its high sensitivity and signal stability. Moreover, it is feasible for both open and laparoscopic gastrectomy in treating early gastric cancer. SN biopsy has brought dramatic changes to laparoscopic surgery for early gastric cancer. With laparoscopic SN biopsy using ICG fluorescence navigation, laparoscopic surgery for early gastric cancer has changed from the uniform standard gastrectomy with D1+ into a tailor-made function-preserving surgical procedure, such as local resection with lymphatic basin dissection.

Long-term effects of gastrectomy in patients with spirometry-defined COPD and patients at risk of COPD: a case-control study

OBJECTIVE

Comorbidities are characteristic of COPD. However, little is known about the secondary manifestations of COPD in the gastrointestinal tract. Therefore, we aimed to explore the long-term effects of gastrectomy in patients with spirometry-defined COPD or those at risk of COPD.

PARTICIPANTS

Subjects included 87 patients either with COPD or at risk of COPD (symptomatic) who underwent gastrectomy between December 2003 and October 2013 (group A), and 174 patients either with COPD or at risk of COPD, matched by age (±5 years), sex, and forced expiratory volume in 1 second (FEV1) as percentage of predicted (FEV1% predicted) (±5%) (group B).

METHODS

All patients underwent routine blood chemistry and pulmonary function tests, arterial blood gas analysis, 6-minute walk test (6MWT), high-resolution chest computed tomography scans, and nutritional assessments.

RESULTS

The mean duration postgastrectomy was 18.3±15.4 years. The mean FEV1 and FEV1% predicted were 2.07±0.76 L and 74.6±24.5%, respectively. Univariate analysis indicated that group A patients had significantly lower body mass index, fat-free mass index, and serum hemoglobin and albumin concentration (all P=0.00), and walked a significantly shorter distance in the 6MWT (P<0.05). Multivariate linear regression analysis for the distance in the 6MWT indicated that increased residual volume (RV) to total lung capacity (TLC) as percentage of predicted (%RV/TLC) alone was an independent and significant predictor of reduced distances in the 6MWT.

CONCLUSION

We concluded that nutritional insufficiency in patients with COPD (or those at risk of COPD) who previously underwent gastrectomy might lead to hyperinflation and consequently, decreased exercise capacity.

A new stage of sentinel node navigation surgery in early gastric cancer

Sentinel node (SN) navigation surgery is expected to realize organ- and function-preserving surgery with SN mapping, and has been applied in operations for breast cancer and melanoma. But there has been no definite evidence for the SN concept in gastric cancer. A prospective multicenter trial to confirm the SN concept for gastric cancer conducted by the Japan Society of Sentinel Node Navigation Surgery reported that the SN detection rate, sensitivity of positive SNs, and accuracy of nodal status are 97.5% (387/397), 93% (53/57), and 99% (383/387), respectively. A detailed analysis of the trial suggested that strictly the "lymphatic basin concept" rather than the "SN concept" was confirmed in early gastric cancer. The Japan Society of Sentinel Node Navigation Surgery started a new trial of function-preserving gastrectomy with lymphatic basin dissection (LBD) for early gastric cancer without metastasis in SNs on the basis of this promising outcome of the trial. It is supposed that LBD guarantees curability in SN navigation surgery for early gastric cancer. Full-thickness resection or endoscopic submucosal dissection in combination with laparoscopic LBD will soon be a new treatment option for early gastric cancer.

Length of negative resection margin does not affect local recurrence and survival in the patients with gastric cancer

AIM: To investigate the influence of the resection margin on local recurrence and survival in gastric cancer patients.

METHODS: We reviewed the medical records of 1788 patients who had undergone gastrectomy for gastric cancer at the Seoul National University Bundang Hospital, South Korea, between May 2003 and July 2009. The patients were divided into early and advanced gastric cancer groups. In each group, we analyzed the relationship between clinicopathologic factors and survival outcomes, and compared the hazard rates of event occurrence between patients with resection margins above and below the cut-off value, using a Cox proportional hazard model.

RESULTS: The early and advanced gastric cancer groups included 1001 and 787 patients, respectively. The hazard rates of event occurrence did not significantly differ between the patients with resection margins above the cut-off value and those with resection margins below the cut-off value (P > 0.05, in all comparisons). Based on the multivariable analyses, the proximal and distal resection margins were not significantly associated with survival outcomes and local recurrence (P > 0.05, in all analyses).

CONCLUSION: The proximal or distal resection margins did not affect the prognosis of patients with gastric cancer if the margins were pathologically negative.

Spontaneous clearance of Helicobacter pylori after pylorus-preserving gastrectomy for gastric cancer

Residual mucosa in the gastric stump after pylorus-preserving gastrectomy (PPG) is considered a risk factor for the development of gastric stump carcinoma (GSC). Duodenogastric reflux (DGR) and Helicobacter pylori (H. pylori) infection are suspected to contribute to the development of GSC. The aim of this study was to investigate the prevalence of H. pylori in the residual stomach after PPG for gastric cancer and to assess factors associated with the presence of H. pylori. We investigated 72 patients who had undergone PPG at least 1 year prior to the study and were confirmed to be positive for H. pylori infection on presurgical endoscopic biopsy. The extent of DGR, the prevalence of H. pylori infection based on H. pylori stool antigen (HpSA) tests and the severity of gastritis were analyzed in these post-PPG patients. None of the patients had DGR, as shown by (99m)Tc-PMT. Of the 72 post-PPG patients, 33 (46%) were positive for HpSA. The prevalence of H. pylori infection was significantly lower after surgery than before surgery. The endoscopic severity of remnant gastritis, as well as histological inflammation and activity, were higher in H. pylori-positive patients than in H. pylori-negative patients. In conclusion, some patients who undergo PPG and are negative for DGR experience spontaneous clearance of H. pylori infection.

Questionnaire survey regarding the current status and controversial issues concerning reconstruction after gastrectomy in Japan

The Japanese Society for the Study of Postoperative Morbidity after Gastrectomy conducted a nationwide questionnaire survey to clarify the current status of reconstruction after gastrectomy. One hundred and forty-five institutions (66%) responded to the survey. The questionnaire dealt with the reconstruction after a distal gastrectomy, pylorus-preserving gastrectomy (PPG), total gastrectomy, and proximal gastrectomy. The most common method of reconstruction after distal gastrectomy was Billroth I in 112 institutions (74%), and Roux-en-Y (RY) in 30 (21%). Seventy-seven institutions (53%) responded to the PPG questions. The lengths of the antral cuff were widely distributed among the institutions. Segmental gastrectomy was performed by 23 institutions for limited cases. The most common method of reconstruction after total gastrectomy was RY in 138 institutions (95%). Reconstruction with a pouch after total gastrectomy was done in 26 institutions (18%). The most common reconstructions after proximal gastrectomy were esophagogastrostomy in 69 institutions (48%), jejunal interposition in 41 (28%), double tract in 19 (13%) and pouch reconstruction in 6 (7%). Although most Japanese surgeons are concerned about the revised methods of reconstruction and quality of life after gastrectomy, surgeons have not yet reached a full consensus on these issues.