Synopsis of a clinical practice guideline for pancreatic ductal adenocarcinoma with peritoneal dissemination in Japan; Japan Peritoneal Malignancy Study Group

Abstract

Patients with pancreatic ductal adenocarcinoma (PDAC) with peritoneal dissemination have a dismal prognosis because discontinuation of systemic chemotherapy is required for massive ascites or poor performance status. The natural history, diagnosis and treatment of PDAC with peritoneal dissemination have not been fully investigated. We systematically reviewed published information on the clinical diagnosis and treatment of PDAC with peritoneal dissemination using the PubMed database (2000‐2020) and provided recommendations in response to clinical questions. This guideline was created according to the "Minds Clinical Practice Guideline Development Guide 2017". The literature quality and body of evidence were evaluated with the GRADE System and classified into four levels (“strong”, “medium”, “weak”, “very weak”). The strength of each final recommendation was decided by a vote of committee members based on the GRADE Grid method. These guidelines address three subjects: diagnostic, chemotherapeutic, and surgical approaches. They include nine clinical questions and statements with recommendation strengths, evidence levels, and agreement rates, in addition to one “column”. This is the English synopsis of the 2021 Japanese clinical practice guideline for PDAC with peritoneal dissemination. It summarizes the clinical evidence for the diagnosis and treatment of PDAC with peritoneal dissemination and provides future perspectives.

Intraperitoneal Paclitaxel Treatment for Patients with Pancreatic Ductal Adenocarcinoma with Peritoneal Dissemination Provides a Survival Benefit

“…In addition, in a second trial that evaluated intravenous gemcitabine, intravenous nab-paclitaxel, and i.p.-PTX in 46 patients, a response rate of 48% and MST of 14.5 (range: 11.5–19.2) months were observed [ 12 ]. Considering these results from two phase II studies, a clinical practice guideline for PDAC with peritoneal dissemination in Japan stated that intraperitoneal chemotherapy is weakly recommended in patients with peritoneal dissemination who do not have a large amount of ascites (off-label use) [ 27 ].…”

Efficacy of staging laparoscopy for resectable pancreatic cancer on imaging and the therapeutic effect of systemic chemotherapy for positive peritoneal cytology

“…Therefore, upfront surgery is probably not recommended as described for peritoneal malignancy in two clinical practice guidelines. 28,29 Furthermore, patients who received systemic chemotherapy for H0P0CY1 and who were to CY-negative had lower CA19-9 levels before starting treatment. Notably, the prognosis of patients who were converted to CY-negative was similar to that of patients with CY0 at the initial diagnosis.…”

“…The median survival of resected patients with CY1 at the time of resection was reported to be 17.5 months in a previous study, 15 but in this study, the MST of all H0P0CY1 patients was extended to 24.2 months following systemic chemotherapy, implying that chemotherapy is effective. Therefore, upfront surgery is probably not recommended as described for peritoneal malignancy in two clinical practice guidelines 28,29 . Furthermore, patients who received systemic chemotherapy for H0P0CY1 and who were converted to CY‐negative had lower CA19‐9 levels before starting treatment.…”

Evaluating staging laparoscopy indications for pancreatic cancer based on resectability classification and treatment strategies for patients with positive peritoneal washing cytology

“…However, the clinical practice guidelines for peritoneal malignancy 2021 suggest that pancreatectomy should not be performed for CY1. 5 In addition, the clinical practice guidelines for pancreatic cancer 2022 from the Japan Pancreas Society states that upfront surgery for CY1 pancreatic cancer is not recommended. 6 Thus, the treatment strategy for CY1 patients remains controversial.…”

“…In the current Japanese guidelines for treating pancreatic cancer (7th edition), CY1 is not treated as distant metastasis. However, the clinical practice guidelines for peritoneal malignancy 2021 suggest that pancreatectomy should not be performed for CY1 5 . In addition, the clinical practice guidelines for pancreatic cancer 2022 from the Japan Pancreas Society states that upfront surgery for CY1 pancreatic cancer is not recommended 6 .…”