Oncological role of surgical resection in patients with pancreatic ductal adenocarcinoma with liver-only synchronous metastases in a single-center retrospective study
Sohei Satoi, Tomohisa Yamamoto, Daisuke Hashimoto, So Yamaki, Yuki Matsui, Tsukasa Ikeura, Shogen Boku, Nobuhiro Shibata, Denys Tsybulskyi, Mitsugu Sekimoto
Abstract
Background: Surgical resection for liver-only synchronous metastases of pancreatic ductal adenocarcinoma remains controversial. We investigated the role of conversion surgery in patients with a favorable response to systemic chemotherapy. Methods: Patients (n=49) were diagnosed liver-only synchronous metastases using staging laparoscopy or open laparotomy between 2007 and 2022. Clinical outcomes were retrospectively compared among patients who underwent conversion surgery (n=10), upfront surgery with or without short-term neoadjuvant chemotherapy (UpS/short NAC) for oligometastases and occult metastases limited to the liver (n=8), and chemotherapy only for resectable or borderline resectable disease with occult liver-only metastases (n=31). The surgical indication of conversion surgery was fixed as the ABC criteria, namely, Anatomical objective response of disappearance of liver metastases on imaging studies, Biological response of CA19-9 level decrease to ≤150 U/mL, and Conditional response of surgical fitness. In addition to the above ABC criteria, tumor disappearance at the liver was repeatedly confirmed using staging laparoscopy (laparoscopic response; L), and metabolic complete responses were confirmed using positron emission tomography-computed tomography (CT) (metabolic response; M). Results: chemotherapy, P=0.554). One patient in the UpS/short NAC group and three in the conversion surgery group achieved 5-year survival. Among them, two patients with initially multiple liver metastases (≥10) in the conversion surgery group survived beyond 5 years. Only conversion surgery was a significant independent prognostic factor in a total cohort (hazard ratio; 0.173, P=0.002). Conclusions: Conversion surgery, but not UpS/short NAC, may enhance survival in patients with synchronous liver metastases and favorably anatomical, biological and conditional responses to systemic chemotherapy.