Gastric Adenocarcinoma: Diagnostic Workup

Daniel Catenacci, MD:When a patient presents with similar symptoms like in this case, we typically start with an upper endoscopy, and in this case, an upper endoscopy revealed a primary tumor in the stomach. At that point, staging scans would be done with CAT scans—chest, abdomen, and pelvis. If there’s no evidence of disease, then an upper endoscopy with ultrasound would be performed to get a better sense of the local stage with the T-stage and end stage. If there’s still evidence of locally advanced disease without evidence of metastatic disease, consideration of a PET scan and then a diagnostic laparoscopy would be performed, particularly in the setting of a T3 or higher or a node-positive cancer. This is because, despite having a normal CAT scan, a normal PET scan, and an endoscopic ultrasound that don’t reveal any evidence that’s definitive for metastatic disease, approximately 20% to 30% of these patients with a T3 or higher, or a node-positive disease, will have an occult metastatic disease to the peritoneum.

A diagnostic laparoscopy is performed in that setting to identify these patients. If it is found to be there, either macroscopy that the surgeon can see or microscopically through cytology washings, then that by definition is now stage 4 disease and curative intent surgery is typically not recommended. So, that patient would be treated like a stage 4 patient, with palliative intent.

If, on the other hand, there is no evidence of metastatic disease, even with diagnostic laparoscopy, then the patient will go down a different treatment path, in terms of perioperative therapy and surgery with curative intent.

Transcript edited for clarity.

A 61-Year-Old Woman With Stage 4 Gastric Cancer

November 2017

• A 61-year-old Hispanic woman presents to her PCP complaining of unexplained weight loss (15 lbs over 6 months), intermittent abdominal pain, fatigue, and recent onset of vomiting
• BMI: 23
• PE: negative for ascites
• Notable laboratory findings:
  • HB: 11.2 g/dL
  • LFT: WNL
  • GFR: 100
  • CEA, 18.4 ng/mL
  • AFP, CA 19-9, and CA 125: WNL
• Upper gastric endoscopy: suspicious 7.2-cm ulcerative lesion involving the pyloric region
• Endoscopic ultrasound: suspicious lymph node
• Biopsy: confirmed poorly differentiated, gastric adenocarcinoma, diffuse histologic subtype; positive lymph node
• Molecular testing: HER2(-), MSI-stable, PD-L1 expression 0%
• CT of chest, abdomen, and pelvis: showed diffuse invasion of the gastric wall and visceral peritoneum, lymph node involvement, 1 hepatic lesion
• Staging: stage IV gastric adenocarcinoma, unresectable
• ECOG PS 0

January 2018

• The patient was started on fluorouracil and oxaliplatin (FOLFOX)
• Follow up CT at 3 months showed a response to systemic therapy

July 2018

• Patient reports increasing nausea, fatigue, and shortness of breath
• CT imaging at 7 months shows metastatic spread to multiple suprapyloric nodes and a new liver lesion
• LFT: mildly elevated; GFR: WNL; HB: 10.8 g/dL
• ECOG PS 1
• Patient is motivated to try another systemic therapy
• Treatment with paclitaxel/ramucirumab is planned