Staging Laparoscopy After Neoadjuvant Treatment for Pancreatic Cancer to Prevent Non-Therapeutic Laparotomy: Analysis in the PREOPANC-2 Randomized Trial

OBJECTIVE: To assess the yield of staging laparoscopy (SL) in a multicenter randomized trial in patients with resectable and borderline resectable pancreatic ductal adenocarcinoma (PDAC) who undergo surgery following neoadjuvant treatment. BACKGROUND: Occult metastases may be detected at exploratory laparotomy, leading to a non-therapeutic laparotomy. Starting such surgical exploration with a SL may prevent this. METHODS: This was a prespecified analysis within the multicenter randomized controlled PREOPANC-2 trial which randomized patients with resectable and borderline resectable PDAC to receive neoadjuvant FOLFIRINOX or neoadjuvant gemcitabine-based chemoradiotherapy and adjuvant gemcitabine. SL was performed in the same surgical session as the intended resection. Primary outcome was yield of SL to prevent a non-therapeutic laparotomy. RESULTS: Among 369 randomized patients, 322 (87.2%) underwent surgical exploration. At surgery, 240 patients (74.5%) underwent SL and 82 (25.5%) underwent laparotomy without SL. Occult metastases were detected in 39/322 patients (12.1%) and was the main reason (90.5%) for aborting surgery without resection. The rate of non-therapeutic laparotomy was lower in the SL group (4.5% vs. 17.1%, P=0.002; NNT 8). Tumor size =3 cm and baseline CA19-9 >500 U/ml were independent predictors for occult metastatic disease. Without these factors, occult metastatic disease was present in 2.8% of patients (95%CI: 0.9-8.0), with one of these factors 14.8% (95%CI: 5.9-32.5) and with both 28.9% (95%CI: 17.0-44.8). CONCLUSIONS: A SL just prior to surgical exploration in patients with PDAC following neoadjuvant treatment was able to detect occult metastases with a NNT of 8. Tailored use of SL only in patients with one or two risk factors would further lower this NNT.