Initial Management of Localized Gastric Adenocarcinoma

Mandatory First Steps

The European Society for Medical Oncology recommends that all cases of localized gastric adenocarcinoma must be discussed in a multidisciplinary team before any treatment decision, including surgeons, medical and radiation oncologists, gastroenterologists, radiologists, and pathologists 1, 2
When local expertise is unavailable, refer patients to an expert center before proceeding, as recommended by the European Society for Medical Oncology 4, 5

A complete staging workup should include a full blood count to assess for iron deficiency anemia, as recommended by the European Society for Medical Oncology 1
Renal and liver function tests should be performed to determine appropriate therapeutic options, according to the European Society for Medical Oncology 1
Contrast-enhanced CT of thorax and abdomen should be performed for staging, as recommended by the European Society for Medical Oncology 3
Endoscopic ultrasound (EUS) should be performed for accurate T and N staging in potentially operable tumors, according to the European Society for Medical Oncology 2
Diagnostic laparoscopy with peritoneal washings should be performed to exclude occult peritoneal metastases, as recommended by the European Society for Medical Oncology 2
HER2 testing should be performed on biopsy specimens for molecular biomarker assessment, according to the European Society for Medical Oncology 3
Nutritional status assessment should be performed to detect dietary deficiencies, as recommended by the European Society for Medical Oncology 3

The European Society for Medical Oncology recommends endoscopic resection (ESD preferred over EMR for lesions >10mm) as a curative treatment for very early disease, only when all of the following criteria are met: confined to mucosa (T1a), well or moderately differentiated (G1-2), non-ulcerated, and <2 cm in diameter 1, 2, 4, 5, 6
For stage IB and above, the standard approach is perioperative chemotherapy combined with surgical resection, as recommended by the European Society for Medical Oncology 1, 2, 3
The preferred regimen for perioperative chemotherapy is triplet chemotherapy with fluoropyrimidine + platinum compound + docetaxel, according to the European Society for Medical Oncology 1, 2, 3
D2 lymphadenectomy (removal of perigastric and second-tier lymph nodes) is the standard surgical approach, as recommended by the European Society for Medical Oncology 1, 2

After curative endoscopic resection, the recurrence risk is 10-20%, requiring structured surveillance, including first follow-up endoscopy at 6 months after resection, and annual endoscopy thereafter, as recommended by the European Society for Medical Oncology 5, 7

The European Society for Medical Oncology recommends avoiding endoscopic resection for diffuse-type gastric cancer, as these require upfront surgery regardless of size or depth 4, 7, 6
Laparoscopy should not be skipped for clinical stage IB-III disease, as occult peritoneal metastases change management in 10-20% of cases, according to the European Society for Medical Oncology 1, 2
Surgery should not be proceeded with before multidisciplinary team discussion, as treatment decisions require multidisciplinary input for optimal outcomes, as recommended by the European Society for Medical Oncology 1, 2, 3
Endoscopic resection should not be used if any high-risk pathologic features are present, as lymph node metastasis risk becomes unacceptably high, according to the European Society for Medical Oncology 4, 5, 6