Can miniprobe endoscopic ultrasound accurately stage esophageal cancer and guide therapeutic decisions in the era of neoadjuvant therapy?

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Background:

Despite recent advancements in imaging techniques adequate diagnostics of esophageal lesions is still challenging. Accurate staging of tumors of the esophagus is a precondition for a targeted therapy. In this multicenter study we report our results of miniprobe EUS in preoperative staging of esophageal lesions in guiding treatment decisions.

Methods:

210 patients recruited from five German centers (Münster, Oldenburg, Hannover, Wiesbaden and Lüneburg) suspicious for esophageal tumor were eventually included. 47 patients were excluded due to prior neoadjuvant therapy. 20 Patients had benign disease. Data from the remaining 143 patients was used for statistical analysis. Basic characteristic are as follows: mean age 63.8±10.7 years, sex: m/f 114/29; tumor distribution (proximal/mid/distal third/multifocal) (n): 3/7/133. In all patients miniprobe EUS was performed and histological correlation either through EMR or surgery was available. uT/uN stages were compared to pT/pN stages. Statistical analysis included calculation ofsensitivity, specificity and accuracy rates.

Results:

The following tumor entities were diagnosed: SCC: 31; adenocarcinoma 112; Overall accuracy for T stage was 60% und 74% for N stage. Sensitivity, specificity and accuracy for miniprobe EUS was as follows (in %): T1: 68/97/83; T2: 39/84/75; T3:72/81/79; T4:13/97/93; T1/2: 73/81/75; T3/4: 78/82/81. Sensitivity and specificity for positive lymph node staging was 76% and 71%, respectively. Determining the therapy regimen according to guidelines for the management of oesophageal and gastric cancer (EMR or radical surgicalresection ifstage 0 and stage 1 (T1m, N0) or primary surgery if T1–2 and N negative, neoadjuvant therapy if T3–4 and/or N positive), 78% of the patients would have been assigned to the adequate therapy regimen. Thus, 11% of patients would have been undertreated and 11% of the patients would have been overtreated. As miniprobe EUS is observer-dependent with learning curves improving staging accuracy with higher case load over time we could observe a highly significant better T stage accuracy in the second half of our study period (73%) compared to the first half (41%, p<0.001).

Summary:

Miniprobe EUS is an established method for the staging of esophageal tumors. Our large multicenter cohort shows a good accuracy of miniprobe EUS for T1/2 tumors (75%) and T3/4 tumors (81%). For N staging miniprobe EUS is not sufficient and requires a multimodal approach. EUS should only be performed in high volume centers as our study showed superiority in EUS staging in experienced endoscopists (learning curve).

endosonography - miniprobe EUS - esophageal tumor - staging - accuracy