Gastric Cancer Surgery | Prof. Sun Yihong (Gastrointestinal Surgery) | CMCS Shanghai

About Prof. Sun Yihong

Prof. Sun Yihong is a senior gastrointestinal surgeon at Zhongshan Hospital, Fudan University — one of China's foremost centres for gastrointestinal oncological surgery and a national reference institution for the multidisciplinary management of gastric cancer, colorectal cancer, and other complex gastrointestinal malignancies. He is recognised for his expertise in laparoscopic and minimally invasive radical gastrectomy, his leadership in multidisciplinary team (MDT) approaches to locally advanced gastric cancer, and his pioneering work in conversion therapy strategies that enable curative resection in patients who present with initially unresectable or borderline resectable disease. Prof. Sun's clinical philosophy holds that locally advanced gastric cancer — particularly cases complicated by adjacent organ invasion, pyloric obstruction, or peritoneal involvement — requires a carefully sequenced multimodal strategy: nutritional optimisation, systemic conversion therapy to achieve tumour downstaging, rigorous radiological reassessment, and, where response is achieved, technically demanding radical surgery to achieve R0 resection. His department at Zhongshan Hospital has established one of Shanghai's most comprehensive gastric cancer surgery programmes, integrating medical oncology, radiology, nutrition support, and minimally invasive surgical technique into a unified MDT care pathway for patients with complex gastric malignancies — a programme that has attracted international recognition, including from visiting surgical experts from Europe.

Case Overview

A patient presented with locally advanced antral gastric cancer complicated by pyloric obstruction and invasion of the pancreatic capsule — a complex presentation that precluded immediate radical resection. Following multidisciplinary team (MDT) discussion, the gastrointestinal surgery team at Zhongshan Hospital formulated a staged treatment strategy: gastrojejunostomy to establish a nutritional bypass and relieve the pyloric obstruction, followed by chemotherapy combined with immunotherapy as conversion therapy to achieve tumour downstaging. Radiological reassessment following conversion therapy demonstrated significant tumour regression. With the tumour now amenable to curative resection, Prof. Sun Yihong designed and performed laparoscopic minimally invasive radical gastrectomy — achieving precise oncological resection of the tumour and involved tissues while maximising preservation of normal physiological function. The procedure was completed successfully and received high commendation from visiting Polish surgical experts. This case exemplifies the capacity of Zhongshan Hospital's gastrointestinal surgery programme to achieve curative outcomes in locally advanced gastric cancer through the integration of MDT collaboration, individualised conversion therapy, and technically advanced minimally invasive surgery.

Patient Background

• Diagnosis: Locally advanced antral gastric cancer (gastric antrum carcinoma) with pyloric obstruction and invasion of the pancreatic capsule
• Clinical presentation: Gastric outlet obstruction secondary to pyloric involvement; nutritional compromise from inability to maintain adequate oral intake; locally advanced disease with pancreatic capsule invasion precluding immediate radical resection
• MDT assessment: Case reviewed by the Zhongshan Hospital gastrointestinal oncology MDT — comprising gastrointestinal surgery, medical oncology, radiology, nutrition support, and anaesthesia — with consensus that immediate radical resection was not feasible and that a staged approach with nutritional optimisation and conversion therapy was required
• Functional status: Nutritional status compromised by pyloric obstruction; performance status assessed and optimised prior to systemic therapy

Diagnostic Workup and Staging

Imaging and Endoscopic Assessment

• CT of chest, abdomen, and pelvis with contrast: Locally advanced antral gastric mass with pyloric obstruction; invasion of the pancreatic capsule; assessment of regional lymph node involvement and distant metastasis — no evidence of distant metastatic disease
• Endoscopy with biopsy: Antral gastric carcinoma confirmed on histopathology; tumour extent and pyloric involvement assessed endoscopically
• PET-CT: Metabolic staging to exclude occult distant metastasis and assess regional nodal involvement
• Staging: Locally advanced gastric cancer — cT4a/b N+ M0; borderline resectable due to pancreatic capsule invasion and pyloric obstruction

Nutritional and Performance Assessment

• Nutritional assessment: significant nutritional compromise secondary to pyloric obstruction; nutritional support plan formulated prior to systemic therapy
• Performance status: assessed and documented; optimisation plan implemented

Prof. Sun's pre-operative assessment (following conversion therapy): When this patient first presented, the combination of pyloric obstruction, pancreatic capsule invasion, and the nutritional compromise from the obstruction made immediate radical surgery both technically hazardous and oncologically suboptimal. The first priority was to restore nutritional intake — the gastrojejunostomy gave us a bypass that allowed the patient to eat and regain nutritional status while we initiated systemic therapy. The conversion therapy — chemotherapy combined with immunotherapy — was selected on the basis of the tumour's molecular profile and the MDT's assessment of the most likely response. The radiological response has been significant: the tumour has regressed substantially, the pancreatic capsule involvement is no longer evident on imaging, and the regional lymph nodes have responded. We are now in a position to offer this patient what we could not offer at presentation — a laparoscopic radical gastrectomy with curative intent. The laparoscopic approach gives us the precision and magnification to work safely in the planes around the pancreas and the major vessels, and the minimally invasive access reduces the physiological insult of the surgery and accelerates the postoperative recovery. The goal is R0 resection — clear margins on all sides — and that is what we will achieve.

Treatment Strategy: Staged Multimodal Approach

The treatment strategy formulated by the Zhongshan Hospital MDT comprised three sequential phases, each building on the outcome of the preceding phase:

Phase 1 — Nutritional Bypass: Gastrojejunostomy

• Laparoscopic gastrojejunostomy performed to bypass the pyloric obstruction and restore enteral nutritional intake
• Objective: restore nutritional status, optimise performance status, and create the physiological conditions for safe systemic therapy
• Outcome: enteral nutrition restored; nutritional status improved; patient able to tolerate systemic therapy

Phase 2 — Conversion Therapy: Chemotherapy Combined with Immunotherapy

• Systemic conversion therapy initiated following nutritional optimisation: chemotherapy regimen combined with immune checkpoint inhibitor therapy, selected on the basis of tumour histopathology, molecular profile, and MDT consensus
• Objective: achieve tumour downstaging — reduction in primary tumour size, resolution of pancreatic capsule invasion, and regional lymph node response — to convert the patient from borderline resectable to resectable with curative intent
• Radiological reassessment following conversion therapy: significant tumour regression confirmed on CT; pancreatic capsule invasion no longer evident; regional lymph node response confirmed; patient deemed suitable for radical resection

Phase 3 — Radical Surgery: Laparoscopic Minimally Invasive Radical Gastrectomy

• Laparoscopic radical gastrectomy designed and performed by Prof. Sun Yihong following MDT confirmation of resectability
• Operative approach: Laparoscopic access; pneumoperitoneum established; systematic exploration of the peritoneal cavity to exclude occult metastatic disease prior to proceeding with resection
• Resection: Radical gastrectomy with D2 lymphadenectomy — en bloc resection of the gastric antrum and the involved perigastric tissues; systematic dissection of the D2 lymph node stations; careful dissection in the plane of the pancreatic capsule to achieve clear margins at the site of prior invasion
• Reconstruction: Gastrointestinal continuity restored with appropriate reconstruction; anastomotic integrity confirmed intraoperatively
• Oncological outcome: R0 resection achieved — clear resection margins confirmed; D2 lymphadenectomy completed; specimen sent for histopathological assessment
• Minimally invasive advantage: Laparoscopic approach provided superior visualisation and magnification for dissection in the peripancreatic plane; reduced intraoperative blood loss; smaller incisions; reduced postoperative pain and earlier return to function compared with open surgery

Treatment Course and Outcomes

Intraoperative

• Laparoscopic radical gastrectomy with D2 lymphadenectomy completed without complication under Prof. Sun Yihong's guidance; R0 resection achieved; intraoperative blood loss minimal; no intraoperative complications; procedure received high commendation from visiting Polish surgical experts observing the case

Postoperative Recovery

• Uncomplicated postoperative course; early mobilisation and enteral nutrition initiated per enhanced recovery after surgery (ERAS) protocol
• Histopathological assessment of resection specimen: confirmed R0 resection; pathological response to conversion therapy assessed; lymph node harvest and nodal status documented
• Patient discharged in good condition; adjuvant therapy plan formulated by MDT based on pathological response assessment
• Survival and quality of life: significantly improved compared with the prognosis at initial presentation; patient able to resume normal daily activities

Prof. Sun's clinical reflection: This case illustrates what is possible when the MDT approach is applied rigorously and the conversion therapy achieves its objective. At presentation, this patient had a tumour that was invading the pancreatic capsule and obstructing the pylorus — a combination that made immediate radical surgery both technically hazardous and likely to result in an R1 or R2 resection. By sequencing the treatment correctly — nutritional bypass first, then conversion therapy, then radical surgery after confirmed response — we were able to offer this patient a laparoscopic R0 resection that would not have been possible at presentation. The laparoscopic approach was not simply a technical preference — it was the right choice for this patient because the magnification and precision of the laparoscopic view allowed us to work safely in the peripancreatic plane and achieve the clear margins that define a curative resection. The commendation from our Polish colleagues reflects the international standard of the surgical technique, but the real measure of success is the patient's outcome — and that outcome was made possible by the entire MDT, from the nutritional support team to the medical oncologists to the surgical team.

Expert Commentary — Prof. Sun Yihong

1. Conversion Therapy for Locally Advanced Gastric Cancer: Principles, Patient Selection, and Response Assessment

Locally advanced gastric cancer — defined as disease that has invaded adjacent structures (T4b) or presents with bulky regional lymph node involvement — has historically been associated with poor prognosis and limited surgical options. The emergence of effective conversion therapy strategies — combining platinum-based chemotherapy with immune checkpoint inhibitors targeting the PD-1/PD-L1 axis — has transformed the management of this patient population by enabling tumour downstaging sufficient to achieve curative resection in a meaningful proportion of patients who would previously have been offered palliative treatment only. The principles of conversion therapy in gastric cancer are straightforward in concept but demanding in execution: the systemic therapy must be sufficiently active to produce meaningful tumour regression; the patient must be able to tolerate the therapy without deterioration in performance status that would preclude subsequent surgery; and the radiological and clinical response must be rigorously assessed at defined intervals to identify the optimal window for surgical intervention — after sufficient downstaging has been achieved, but before the cumulative toxicity of systemic therapy compromises the patient's surgical fitness. Patient selection for conversion therapy requires careful MDT assessment: tumours with high PD-L1 expression, microsatellite instability (MSI-H), or Epstein-Barr virus positivity are more likely to respond to immunotherapy-containing regimens; HER2-positive tumours may benefit from the addition of trastuzumab; and the molecular profile of the tumour should inform the selection of the conversion therapy regimen. In this patient, the combination of chemotherapy and immunotherapy produced a radiological response that converted a borderline resectable tumour to one amenable to laparoscopic R0 resection — the optimal outcome of a well-executed conversion therapy strategy.

2. Laparoscopic Radical Gastrectomy with D2 Lymphadenectomy: Technical Demands and Oncological Principles

Laparoscopic radical gastrectomy with D2 lymphadenectomy is the standard of care for resectable gastric cancer at high-volume centres in East Asia, supported by level 1 evidence from randomised controlled trials demonstrating equivalent oncological outcomes to open surgery with the well-established minimally invasive advantages of reduced blood loss, shorter hospital stay, and faster return to function. The technical demands of laparoscopic D2 gastrectomy are substantial: the D2 lymphadenectomy requires systematic dissection of the perigastric, hepatic, splenic, and coeliac lymph node stations — a dissection that demands precise anatomical knowledge, meticulous haemostasis, and the ability to work safely in close proximity to the portal vein, the superior mesenteric vessels, and the pancreas. In cases where conversion therapy has been administered for locally advanced disease with adjacent organ invasion — as in this patient, where the pancreatic capsule was involved at presentation — the surgical dissection is further complicated by the fibrotic changes induced by the systemic therapy in the peritumoral tissues. These fibrotic changes can obscure the normal tissue planes and increase the risk of inadvertent injury to adjacent structures; they require the surgeon to work with particular precision and patience in the affected planes, using the magnification and illumination of the laparoscope to identify and follow the correct dissection plane. The achievement of R0 resection — clear margins on all sides of the resection specimen — is the primary oncological objective of radical gastrectomy and the strongest predictor of long-term survival in resectable gastric cancer. In this patient, R0 resection was achieved laparoscopically in a case that had presented with pancreatic capsule invasion — a result that reflects both the effectiveness of the conversion therapy in achieving tumour regression and the technical precision of the laparoscopic surgical approach.

3. The MDT Framework in Gastric Cancer: Integrating Surgery, Oncology, Nutrition, and Rehabilitation

The multidisciplinary team approach to gastric cancer management is not a bureaucratic formality — it is the clinical framework that makes complex cases like this one achievable. The decision to perform gastrojejunostomy as the first intervention — rather than proceeding directly to attempted radical resection or initiating systemic therapy in a nutritionally compromised patient — was an MDT decision that required the integration of surgical, oncological, and nutritional perspectives. The nutritional support team's assessment of the patient's nutritional status and the feasibility of maintaining adequate nutrition through systemic therapy informed the decision to establish a surgical bypass before initiating chemotherapy. The medical oncology team's selection of the conversion therapy regimen — informed by the tumour's molecular profile and the available evidence for immunotherapy-containing regimens in locally advanced gastric cancer — was the intervention that made the subsequent radical surgery possible. The radiology team's rigorous assessment of the radiological response to conversion therapy — using standardised response criteria and comparison with the pre-treatment baseline imaging — provided the objective evidence of tumour downstaging that justified proceeding to radical surgery. And the surgical team's technical execution of the laparoscopic radical gastrectomy — in a patient whose tumour had previously invaded the pancreatic capsule — was the culmination of a treatment strategy that had been planned and executed by the entire MDT from the first consultation. This is the MDT model at its best: each discipline contributing its expertise at the right moment in the treatment sequence, with the patient's outcome as the shared objective.

How CMCS Shanghai Coordinated This Case

CMCS Shanghai supported the patient and family throughout the multidisciplinary diagnostic, treatment, and surgical pathway at Zhongshan Hospital, Fudan University, including: priority MDT consultation coordination with the Zhongshan Hospital gastrointestinal oncology team, with bilingual review of all prior imaging, endoscopy, histopathology, and clinical records; bilingual interpretation throughout all MDT discussions, surgical planning consultations, medical oncology consultations, and postoperative review appointments; coordination of CT staging, PET-CT, endoscopy, and nutritional assessment with bilingual results communication and clinical summary; bilingual explanation of the staged treatment strategy — gastrojejunostomy, conversion therapy, and radical surgery — including the rationale for each phase, the expected timeline, and the criteria for proceeding from one phase to the next; coordination of conversion therapy administration including bilingual liaison with the medical oncology team, written treatment schedule, and monitoring of treatment response; bilingual surgical consent process for both the gastrojejunostomy and the laparoscopic radical gastrectomy; postoperative care coordination including bilingual communication of histopathological results, adjuvant therapy planning, and long-term oncological follow-up scheduling.

For international patients with gastric cancer — including locally advanced cases requiring conversion therapy prior to surgery — seeking specialist surgical evaluation and multidisciplinary oncological management in Shanghai, Prof. Sun Yihong's team at Zhongshan Hospital, Fudan University, offers a clinically rigorous, internationally recognised approach combining MDT expertise, effective conversion therapy strategies, and technically advanced laparoscopic radical surgery. CMCS ensures that expertise is accessible: in the patient's language, with every step of the complex multimodal treatment pathway coordinated and communicated clearly, from the first MDT consultation through long-term oncological follow-up.

This case report is de-identified and published for educational purposes. All clinical details have been anonymized in accordance with patient privacy standards. CMCS Shanghai is a medical concierge service and does not provide direct medical care.