Treatment Approach for Gastric Antrum Carcinoma

Initial Diagnostic Workup and Staging

The European Society for Medical Oncology recommends complete staging, including endoscopy with biopsy to confirm adenocarcinoma histology, determine Lauren classification, and obtain tissue for HER2 testing if metastatic disease is suspected, as well as contrast-enhanced CT of thorax, abdomen, and pelvis to detect lymphadenopathy, metastatic disease, and assess resectability 1, 2
Laparoscopy with peritoneal washings is recommended for all stage IB-III cancers to exclude occult peritoneal metastases not visible on imaging 1, 3
Blood tests, including complete blood count, liver and renal function tests, are necessary for initial diagnostic workup 1, 2

The American Society of Clinical Oncology recommends that all treatment decisions be made by a multidisciplinary team, including surgeons, medical oncologists, radiation oncologists, gastroenterologists, radiologists, pathologists, dieticians, and nurse specialists, before proceeding with treatment 1, 2, 5

For very early disease (T1a), endoscopic resection alone is appropriate if all criteria are met, including confined to mucosa, well-differentiated histology, non-ulcerated, ≤2 cm in diameter, and no lymphovascular invasion 1, 2, 5
For localized resectable disease (stage IB and above), perioperative chemotherapy followed by surgery followed by completion of chemotherapy is the standard of care, with preoperative chemotherapy consisting of 3 cycles of ECF or ECX regimen, and postoperative chemotherapy completing the remaining 3 cycles of the same regimen 1, 2, 5
The perioperative approach improved 5-year survival from 23% to 36.3% in the landmark MAGIC trial 4, 5

Distal gastrectomy with D2 lymphadenectomy is the appropriate operation for antral location, with removal of perigastric nodes and nodes along celiac arterial branches 5, 3
Resection margins should achieve ≥3 cm margins for Borrmann I-II tumors and ≥5 cm for Borrmann III-IV tumors 3
Splenectomy should not be performed unless the tumor directly invades the spleen, as it increases complications without survival benefit 3

Concurrent chemoradiation is recommended for good performance status patients with unresectable locally advanced disease, with chemotherapy options including capecitabine + paclitaxel, cisplatin + fluoropyrimidine, or oxaliplatin + fluoropyrimidine given concurrently with radiation 3

Palliative combination chemotherapy should be offered to patients with good performance status, with first-line regimen consisting of docetaxel + cisplatin + fluorouracil, or alternative first-line regimen consisting of ECF or ECX regimen 1, 6, 7, 2
HER2-positive tumors should be treated with trastuzumab added to first-line platinum/fluoropyrimidine doublet 2

Do not proceed to surgery without laparoscopy in potentially resectable stage IB-III disease, as imaging misses peritoneal metastases in a significant proportion of patients 1, 3
Do not accept inadequate lymph node evaluation, as this leads to understaging and suboptimal treatment planning 1, 5, 3
Do not perform routine splenectomy, as it increases morbidity without oncologic benefit 3

Symptom-driven visits are recommended rather than intensive routine surveillance, as regular intensive follow-up does not improve outcomes 6, 7, 2, 5