Next Best Step: Endoscopic Ultrasound (EUS) and PET-CT
The next best step is to perform endoscopic ultrasound (EUS) with fine-needle aspiration and PET-CT imaging to complete staging of the gastroesophageal junction adenocarcinoma, as these modalities are essential for determining locoregional extent and detecting occult metastatic disease not visible on standard CT imaging. 1, 2
Rationale for EUS and PET-CT
The NCCN guidelines explicitly recommend that EUS and PET-CT evaluation should be performed if metastatic cancer is not evident on initial CT imaging 1. Since your patient has unremarkable chest and abdominal CT scans, this indicates apparent locoregional disease requiring further characterization before treatment planning.
Why EUS is Critical
- EUS provides superior accuracy for T-staging (depth of tumor invasion) and N-staging (regional lymph node involvement) compared to CT alone, with particular value in distinguishing T1a from T1b tumors and evaluating T2 lesions 1, 3
- EUS with fine-needle aspiration achieves 75% overall accuracy for determining nodal status, significantly better than clinical examination or CT alone 3
- T-stage determination directly impacts treatment selection—whether the patient needs neoadjuvant therapy versus upfront surgery 1
Why PET-CT is Essential
- PET-CT identifies occult distant metastases in approximately 15-20% of patients with apparently locoregional disease on conventional CT 2
- PET-CT improves lymph node staging and detection of stage IV disease, serving as an independent predictor of overall survival 1
- The addition of PET-CT to standard staging changes multidisciplinary treatment recommendations in 38.2% of patients, improving selection for radical treatment versus palliative approaches 1
Additional Required Staging Elements
Beyond EUS and PET-CT, ensure completion of the following:
- Assessment of Siewert tumor type (I, II, or III) is mandatory for all GEJ adenocarcinomas, as this determines the surgical approach (esophagectomy versus gastrectomy) 1, 2
- HER2/neu testing should be performed now if metastatic disease is documented or suspected during staging, as this directly impacts systemic therapy selection 1, 2
- Complete blood count and comprehensive metabolic panel to assess treatment eligibility 2, 4
Optional Staging Considerations
- Laparoscopic staging of the peritoneal cavity should be considered for GEJ adenocarcinomas if there is no evidence of M1 disease, particularly for locally advanced tumors, as peritoneal metastases may not be visible on CT 1, 4
- Bronchoscopy is only indicated if the tumor is located at or above the carina, which is unlikely for a GEJ tumor 1
Common Pitfalls to Avoid
- Do not proceed directly to surgery without completing staging with EUS and PET-CT, as approximately 15-38% of patients will have their stage or treatment plan changed by these modalities 1, 2
- Do not assume unremarkable CT scans mean early-stage disease—CT has limited sensitivity for lymph node metastases and small peritoneal deposits 3
- Ensure the endoscopic biopsy documented tumor location, length, circumferential involvement, and distance from incisors, as these details are essential for surgical planning 2, 4
- Do not order PET alone without CT—combined PET-CT is the recommended modality, not PET in isolation 1, 4
What Happens After Complete Staging
Once EUS and PET-CT are completed, the patient should be discussed in a multidisciplinary tumor board before initiating treatment 2. Treatment pathways will depend on final stage:
- For T1b-T2 tumors: Options include neoadjuvant therapy followed by surgery versus surgery alone, depending on risk features 1, 2
- For locally advanced resectable tumors (T2-T4a, any N): Preoperative chemoradiation is preferred, with perioperative chemotherapy as an alternative 1, 5
- For unresectable or metastatic disease: Systemic chemotherapy with HER2-targeted therapy (if HER2-positive) becomes the primary treatment 2