Surgery Matters: Progress in Surgical Management of Gastric Cancer.

OPINION STATEMENT: The surgical treatment of gastric carcinoma has progressed significantly in the past few decades. A major milestone was the establishment of multimodal therapies for locally advanced tumours. Improvements in the technique of endoscopic resection have supplanted surgery in the early stages of many cases of gastric cancer. In cases in which an endoscopic resection is not possible, surgical limited resection procedures for the early stages of carcinoma are an equal alternative to gastrectomy in the field of oncology. Proximal gastrectomy is extensively discussed in this context. Whether proximal gastrectomy leads to a better quality of life and better nutritional well-being than total gastrectomy depends on the reconstruction chosen. The outcome cannot be conclusively assessed at present. For locally advanced stages, total or subtotal gastrectomy with D2 lymphadenectomy is now the global standard. A subtotal gastrectomy requires sufficiently long tumour-free proximal resection margins. Recent data indicate that proximal margins of at least 3 cm for tumours with an expansive growth pattern and at least 5 cm for those with an infiltrative growth pattern are sufficient. The most frequently performed reconstruction worldwide following gastrectomy is the Roux-en-Y reconstruction. However, there is evidence that pouch reconstruction is superior in terms of quality of life and nutritional well-being. Oncological gastric surgery is increasingly being performed laparoscopically. The safety and oncological equivalency were first demonstrated for early carcinomas and then for locally advanced tumours, by cohort studies and RCTs. Some studies suggest that laparoscopic procedures may be advantageous in early postoperative recovery. Robotic gastrectomy is also increasing in use. Preliminary results suggest that robotic gastrectomy may have added value in lymphadenectomy and in the early postoperative course. However, further studies are needed to substantiate these results. There is an ongoing debate about the best treatment option for gastric cancer with oligometastatic disease. Preliminary results indicate that certain patient groups could benefit from resection of the primary tumour and metastases following chemotherapy. However, the exact conditions in which patients may benefit have yet to be confirmed by ongoing trials.

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.

Preservation of hepatic branch of the vagus nerve reduces the risk of gallstone formation after gastrectomy.

BACKGROUND: Injury to the vagus nerve has been proposed to be associated with occurrence of gallstones after gastrectomy. We investigated the effect of preservation of hepatic branch of the vagus nerve on prevention of gallstones during laparoscopic distal (LDG) and pylorus-preserving gastrectomy (LPPG). METHODS: Preservation of the vagus nerve was reviewed of cT1N0M0 gastric cancer patients underwent LDG (n = 323) and LPPG (n = 144) during 2016-2017. Presence of gallstones was evaluated by ultrasonography (US) and computed tomography (CT). Incidences of gallstones were compared between the nerve preserved (h-DG, h-PPG) group and sacrificed (s-DG, s-PPG) group. Clinicopathological features were also compared. RESULTS: The 3-year cumulative incidence of gallstones was lower in the h-DG (2.7%, n = 85) than the s-DG (14.6%, n = 238) (p = 0.017) and lower in the h-PPG (1.6%, n = 123) than the s-PPG (12.9%, n = 21) (p = 0.004). Overall postoperative complication rate was similar between the h-DG and s-DG (p = 0.861) as well as between the h-PPG and s-PPG (p = 0.768). The number of retrieved lymph nodes station #1 and 3-year recurrence-free survival were not significantly different between the preserved group and sacrificed group. Injury to the vagus nerve (p = 0.001) and high body mass index (BMI) (≥ 27.5 kg/m2) (p = 0.040) were found to be independent risk factors of gallstone formation in multivariate analysis. CONCLUSIONS: Preservation of hepatic branch of the vagus nerve can be recommended for LDG as well as LPPG of early gastric cancer patients to reduce postoperative gallstone formation.

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.

Gastric Cancer Surgery: Balancing Oncological Efficacy against Postoperative Morbidity and Function Detriment.

Significant progress has been made in the surgical management of gastric cancer over the years, and previous discrepancies in surgical practice between different parts of the world have gradually lessened. A transition from the earlier period of progressively more extensive surgery to the current trend of a more tailored and evidence-based approach is clear. Prophylactic resection of adjacent anatomical structures or neighboring organs and extensive lymph node dissections that were once assumed to increase the chances of long-term survival are now performed selectively. Laparoscopic gastrectomy has been widely adopted and its indications have steadily expanded, from early cancers located in the distal part of the stomach, to locally advanced tumors where total gastrectomy is required. In parallel, function-preserving surgery has also evolved and now constitutes a valid option for early gastric cancer. Pylorus-preserving and proximal gastrectomy have improved the postoperative quality of life of patients, and sentinel node navigation surgery is being explored as the next step in the process of further refining the minimally invasive concept. Moreover, innovative techniques such as indocyanine green fluorescence imaging and robot-assisted gastrectomy are being introduced in clinical practice. These technologies hold promise for enhancing surgical precision, ultimately improving the oncological and functional outcomes.

Long­term survival prognosis of function­preserving 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).

Short-term Outcomes of Pylorus-Preserving Gastrectomy for Early Gastric Cancer: Comparison Between Extracorporeal and Intracorporeal Gastrogastrostomy.

PURPOSE: This study aimed to compare the surgical and oncological outcomes between totally laparoscopic pylorus-preserving gastrectomy (TLPPG) with intracorporeal anastomosis and laparoscopy-assisted pylorus-preserving gastrectomy (LAPPG) with extracorporeal anastomosis. MATERIALS AND METHODS: A retrospective analysis was performed in 258 patients with cT1N0 gastric cancer who underwent laparoscopic pylorus-preserving gastrectomy using two different anastomosis methods: TLPPG with intracorporeal anastomosis (n=88) and LAPPG with extracorporeal anastomosis (n=170). The following variables were compared between the two groups to assess the postoperative surgical and oncological outcomes: proximal and distal margins, number of resected lymph nodes (LNs) in total and in LN station 6, operation time, postoperative hospital stay, and postoperative morbidity including delayed gastric emptying (DGE). RESULTS: The average length of the proximal margin was similar between the TLPPG and LAPPG groups (2.35 vs. 2.73 cm, P=0.070). Although the distal margin was significantly shorter in the TLPPG group than in the LAPPG group (3.15 vs. 4.08 cm, P=0.001), no proximal or distal resection margin-positive cases were reported in either group. The average number of resected LN was similar in both groups (36.0 vs. 33.98, P=0.229; LN station 6, 5.72 vs. 5.33, P=0.399). The operation time was shorter in the TLPPG group than in the LAPPG (200.17 vs. 220.80 minutes, P=0.001). No significant differences were observed between the two groups in terms of postoperative hospital stay (9.38 vs. 10.10 days, P=0.426) and surgical complication rate (19.3% vs. 22.9%), including DGE (8.0% vs. 11.8%, P=0.343). CONCLUSIONS: The oncological safety and postoperative complications of TLPPG with intracorporeal anastomosis are similar to those of LAPPG with extracorporeal anastomosis.

[Chinese expert consensus on function-preserving gastrectomy for gastric cancer (2021 edition)].

With the development of surgical treatment for gastric cancer, under the premise of ensuring the effect of surgical treatment, the objectives of preserving the function of stomach, diminishing the influence of quality of life and keeping the outcome of treatment, are the expectation of patients and the goal of surgeons. The emerge of function-preserving gastrectomy (FPG) indicates that the surgical treatment of gastric cancer steps into the individualized and precision era. Because the concept and operation procedures of FPG have not achieved consensus, the Gastrointestinal Surgery Branch, Surgery Branch, Chinese Medical Association (CMA) with Chinese Society of Surgical Oncology of Chinese Medical Doctor Association(CMDA), Chinese Society of Upper Gastrointestinal Surgeon of CMDA, Stomach and Intestines Committee of Chinese Anticancer Association, convenes some experts to summarize the recent literatures and discuss to reach the consensus about the FPG in the treatment of early gastric cancer. The definition of FPG is as follows: without compromising the oncological efficacy of early gastric cancer, decrease of the operational scale, selection of optimal reconstruction procedures and preservation of the gastric function as much as possible. The most common operation methods are procedures of minimized scale (pylorus-preserving gastrectomy, segmental gastrectomy, local gastrectomy and endoscopic resection) and proximal gastrectomy (PG). Besides the anastomosis of esophagus and gastric remnants, the reconstruction method after proximal gastrectomy also includes tubular gastroesophagostomy, double tract reconstruction, Interposition jejunostomy, side to side gastroesophagostomy (SOFY), double flap gastroesophagostomy (Kamikawa anastomosis), etc. The evaluation of gastric function after FPG includes the assessment of gastric remnant function, the functional complications and the nutritional status. We believe the publication of consensus will properly popularize FPG, promote further research about the gastric cancer and function of gastric remnant, and improve the theoretical study about FPG. Moreover, the indications and procedures of FPG will be broadened and renovated.

[Interpretation of key points of Chinese expert consensus on function-preserving gastrectomy for gastric cancer (2021)].

Gastric cancer is one of the most common malignant tumors in China, and with the popularity of gastroscopy in recent years, the proportion of early gastric cancer is increasing gradually. Through standardized endoscopic and/or surgical treatment, patients with early gastric cancer usually have a favorable prognosis, which will inevitably lead to higher demands for postoperative quality of life. Based on this situation, function-preserving gastrectomy (FPG) has become a focus in the treatment of early gastric cancer for the purpose of improving the quality of life. The "Chinese expert consensus on function-preserving gastrectomy for early gastric cancer (2021)" will guide surgeons to perform standardized FPG, and ensure the maximum quality of life for the patients.

[Functional evaluation after function-preserving gastrectomy].

With the increase of people's health awareness and the progress of medical diagostic technology in recent years, the diagnosis rate of early gastric cancer is increasing year by year. Although radical surgery has good efficacy, how to maximize the preservation of the normal anatomy and function of the stomach and improve the quality of life of patients in the pursuit of radical surgery has become a more important issue in the treatment of early gastric cancer. Under the condition of ensuring radical lymph node dissection, function-preserving gastrectomy can fully preserve gastric function by reducing the resection extent and preserving the pylorus and the vagus nerve, which has advantage of improving quality of life and has great potential in the treatment of early gastric cancer. However, there is no functional evaluation standard for function-preserving gastrectomy at present. Most of the patients are evaluated by quality of life scale, which is relatively subjective. Even though the evaluation of endoscopy, hematology and other objective means can indicate the benefit degree in quality of life brought by functional reconstruction, the evidence level is limited. Therefore, this paper discusses the research status of function-preserving gastrectomy evaluation, postoperative complications, postoperative nutritional status, auxiliary examination and other items in the evaluation of gastric function, and analyzes the prospects of research direction in this field.

[Pylorus-preserving gastrectomy and segmental gastrectomy: discrimination of concepts and surgical procedures].

Both pylorus-preserving gastrectomy (PPG) and segmental gastrectomy (SG) achieve the preservation of gastric cardia and pylorus through the circumferential resection of stomach, while concepts and surgical procedures of these two operations are obviously different. In this sense, transectional gastrectomy includes both PPG and SG. PPG is one of the standard surgical procedure for early gastric cancer (EGC). The extent of lymph node dissection (No.1, 3, 4sb, 4d, 6, 7, 8a, 9) and the retention of infrapyloric vessels, hepatic and pyloric branch of vagal nerve has formed a consensus. Meanwhile, SG is regarded as an investigational treatment according to the Japanese gastric cancer treatment guidelines. It is still controversial and may generate an ethical risk in the clinical practice. This article distinguishes the difference in the concepts and surgical procedures between PPG and SG, assisting a comprehensive evaluation in further research.

Current status of function-preserving gastrectomy for gastric cancer.

Early gastric cancer (EGC) has excellent postoperative survival outcomes; thus, one of the recent keywords in the treatment of EGC is "function-preserving gastrectomy (FPG)." FPG reduces the extent of lymphadenectomy and gastric resection without compromising the long-term prognosis. Proximal gastrectomy (PG) is an alternative to total gastrectomy (TG) for EGC in the upper-third of the stomach, in which the gastric reservoir, gastric acid secretion, and intrinsic factors are maintained. Distal gastrectomy (DG) with a small remnant stomach, namely subtotal gastrectomy (STG), is another option for upper EGC, where the function of the cardia and fundus is preserved. Pylorus-preserving gastrectomy (PPG) is a good alternative to DG for EGC in the middle-third of the stomach, where pyloric function is preserved. Following elucidation of the markedly low incidences of possible metastasis to lymph node stations where dissection is omitted, the oncological safety of these FPG procedures was clarified. Nutritional advantages of PG or STG over TG have been reported; however, the standardized reconstruction methods after PG are yet to be established, and it is important to devise methods to prevent postoperative gastroesophageal reflux and anastomotic complications regardless of the reconstruction method. Nutritional benefits of PPG compared with DG have also been clarified, in which reducing postoperative gastric stasis is important. For the further spread of these FPG procedures, several issues, such as precise evaluation of preserved function, confirmation of oncological safety, and standardization of the technique, should be addressed in future prospective randomized controlled trials.

[Choice of function-preserving gastrectomy].

As the diagnosis rate of early gastric cancer is increasing annually, the current hot spot in the treatment of early gastric cancer is how to better preserve the anatomical structure and physiological function of the stomach and improve the quality of life of patients after surgery under the premise of tumor eradication. Therefore, function-preserving gastrectomy has been the trend of surgical treatment for early gastric cancer. It is not just a modified gastrectomy, but a better combination of improved surgical techniques and the concept of function-preserving treatment, rather than being limited to traditional surgical treatments. Currently, the routine function-preserving gastrectomy mainly includes pylorus-preserving gastrectomy, proximal gastrectomy and partial gastrectomy combined with endoscopy. In addition, with the deeper understanding of metastasis pattern of gastric cancer and the development and popularization of minimally invasive techniques, laparoscopic and endoscopic cooperative surgery is gradually gaining attention. The application of laparoscopic and endoscopic hybrid surgery combined with sentinel lymph node navigation is anticipated in the treatment of early gastric cancer.

[Significance of celiac branch of the vagal nerve in function-preserving gastrectomy].

Function-preserving gastrectomy, especially pylorus-preserving gastrectomy (PPG), can improve the quality of life and has been widely recognized. With the development of surgical techniques and equipment, nerve preservation has become a new requirement in the era of "precision medicine", but the preservation of celiac branch of the vagal nerve remains controversial in gastric cancer surgery. Current researches have shown that the preservation of celiac branch of the vagal nerve is safe and feasible in patients with early gastric cancer. Although controversial, nerve preservation may play a role in preventing gallstones, regulating gastric emptying, reducing dumping syndrome, alleviating chronic diarrhea, reducing gastroesophageal reflux, and inhibiting bile reflux. The significance of the celiac branch of the vagal nerve in gastric cancer surgery is worth further attention and exploration to promote the development of function-preserving gastrectomy and improve the quality of life of patients.

[Segmental gastrectomy with cardia preservation for early gastric cancer].

Segmental gastrectomy with cardia preservation can reduce the symptoms of postoperative gastroesophageal reflux and improve the quality of life, which is potentially advantageous among function-preserving gastrectomy procedures. However, due to the limited extent of excision, this procedure is classified as an investigational treatment in the Japanese Gastric Cancer Treatment Guidelines, without wide acceptance in clinical practice. It is generally believed that the surgical indication of segmental gastrectomy is more selected compared to the pylorus-preserving gastrectomy, and there are also differences between their therapeutic goals. The indications of cardia preservation in segmental gastrectomy mainly depend on the T stage, the distance of the resection margin and the metastasis of lymph nodes. Other points of segmental gastrectomy mainly include the scope of lymphadenectomy, the preservation of blood vessels and vagal nerves, which are still controversial in different researches. High-quality evidences are needed to confirm the safety and long-term efficacy of the segmental gastrectomy.

Burgeoning study of sentinel-node analysis on management of early gastric cancer after endoscopic submucosal dissection.

Endoscopic submucosal dissection (ESD) represents an organ-preserving alternative to surgical resection of early gastric cancer. However, even with ESD yielding en-bloc resection specimens, there are concerns regarding tumor spread such as with larger lesions, ulcerated lesions, undifferentiated pathology and submucosal invasion. Sentinel node navigational surgery (SNNS) when combined with ESD offers a minimally invasive alternative to the traditional extended gastrectomy and lymphadenectomy if lack of lymph node spread can be confirmed. This would have a clear advantage in terms of potential complications and quality of life. However, SNNS, though useful in other malignancies such as breast cancer and melanoma, may not have a sufficient sensitivity for malignancy and negative predictive value in EGC to justify this as standard practice after ESD. The results of SNNS may improve with greater standardization and more involved dissection, technological innovations and more experience and validation such that the paradigm for post-ESD resection of EGC may change and include SNNS.

Functional and nutritional outcomes after gastric cancer surgery.

Recent improvements in diagnostic techniques and national screening programs have resulted in increasing number of patients diagnosed with early gastric cancer (EGC). The low incidence rate of lymph node metastasis and excellent survival rates after surgical treatment for EGC enabled the reduction in the extent of lymphadenectomy and the range of gastric resection for function-preserving gastrectomy. Thus, the quality of life (QOL) of patients with gastric cancer (GC) in the curative stage can be maintained. Moreover, these function-preserving procedures have been widely performed by less invasive procedures, such as laparoscopic and robotic approaches. Pylorus-preserving gastrectomy (PPG) and proximal gastrectomy (PG) represent the two main function-preserving surgical procedures for GC. PPG is an alternative to distal gastrectomy (DG) for cT1 N0 EGC located in the middle part of the stomach. Preservation of the pyloric function is expected to prevent post-gastrectomy syndromes such as dumping syndrome. PG is an alternative to total gastrectomy (TG) and can thus be performed for cT1 N0 EGC located in the upper part of the stomach. Preservation of the residual stomach is expected to work as a reservoir for ingested food. The optimal reconstruction method after PG among the three most commonly performed procedures (esophagogastrostomy, jejunal interposition, and double-tract reconstruction) remains controversial. In addition to these three reconstruction methods, the novel double-flap technique (DFT) of esophagogastrostomy has gained attention recently because of its potential usefulness to prevent postoperative esophageal reflux. In this review article, we summarize the current evidence of PPG and PG with esophagogastrostomy by the DFT, focusing on postoperative nutrition and QOL.

Function-preserving surgery for gastric cancer: current status and future perspectives.

The number of early gastric cancer (EGC) cases has been increasing because of improved diagnostic procedures including endoscopy and screening systems. Therefore, function-preserving gastrectomy (FPG) for EGC with the expectation of better quality of life (QOL) after surgery may be increasingly utilized, due to its association with low rate of lymph node metastasis and excellent survival and the possibility of employing less invasive procedures such as laparoscopic gastrectomy in combination. Pylorus-preserving gastrectomy (PPG) with curative intent lymph node dissection is a representative FPG that has been used in EGC, and its superiorities, indications, limitations, and survival benefits have already been reported in several retrospective studies. Laparoscopic proximal gastrectomy (LAPG) has also been employed in EGC of the upper third of the stomach; however, LAPG was found to be associated with major issues in achieving a balance between swallowing and reflux prevention. In patients with EGC in the upper third of the stomach, laparoscopy-assisted subtotal gastrectomy with a preserved, albeit very small, stomach may provide a better QOL and fewer postoperative complications. FPG is recommended as a surgical treatment for EGC if the indication is accurately diagnosed and strictly confirmed; however, these techniques in laparoscopic surgery present technical difficulties to surgeons without a certain degree of skills. Although many retrospective studies revealed the functional benefits or oncological safety with FPG, further prospective studies using large case series are necessary to reveal the value of FPG compared with the conventional procedures.

Function-preserving gastrectomy for gastric cancer in Japan.

Surgery used to be the only therapy for gastric cancer, and since its ability to cure gastric cancer was the focus of attention, less attention was paid to function-preserving surgery in gastric cancer, though it was studied for gastroduodenal ulcer. Maki et al developed pylorus-preserving gastrectomy for gastric ulcer in 1967. At the same time, the definition of early gastric cancer (EGC) was being considered, histopathological investigations of EGC were carried out, and the validity of modified surgery was sustained. After the development of H2-blockers, the number of operations for gastroduodenal ulcers decreased, and the number of EGC patients increased simultaneously. As a result, the indications for pylorus-preserving gastrectomy for EGC in the middle third of the stomach extended, and various alterations were added. Since then, many kinds of function-preserving gastrectomies have been performed and studied in other fields of gastric cancer, and proximal gastrectomy, jejunal pouch interposition, segmental gastrectomy, and local resection have been performed. On the other hand, from the overall perspective, it can be said that endoscopic resection, which was launched at almost the same time, is the ultimate function-preserving surgery under the current circumstances. The current function-preserving gastrectomies that are often performed and studied are pylorus-preserving gastrectomy and proximal gastrectomy. The reasons for this are that these procedures that can be performed with systemic lymph node dissection, and they include three important elements: (1) reduction of the extent of gastrectomy; (2) preservation of the pylorus; and (3) preservation of the vagal nerve. In addition, these operations are more likely to be performed with a laparoscopic approach as minimally invasive surgery. Of the above-mentioned three elements, reduction of the extent of gastrectomy is the most important in our view. Therefore, we should try to reduce the extent of gastrectomy if curability of the gastric cancer can still be achieved. However, if we preserve a wider residual stomach in function-preserving gastrectomy, we should pay attention to the development of metachronous gastric cancer.