Published online Jul 27, 2023. doi: 10.4240/wjgs.v15.i7.1512
Peer-review started: January 26, 2023
First decision: February 7, 2023
Revised: February 22, 2023
Accepted: May 5, 2023
Article in press: May 5, 2023
Published online: July 27, 2023
Processing time: 175 Days and 16.8 Hours
Pancreatic ductal adenocarcinoma (PDAC) remains a leading cause of cancer death globally, with a substantial number of patients presenting with metastatic disease and typical survival of less than 12 mo. Furthermore, up to 75% of patients who undergo surgical resection and adjuvant therapy for primary PDAC will experience disease recurrence within 2 years and two thirds of those will have metastatic disease. International practice guidelines consistently suggest palliative treatment pathways for these patients. Nonetheless, there is an increasing body of evidence in the form of small case series and reports that present promising oncological outcomes following resection of metachronous and even synchronous isolated liver metastases from PDAC primary.
A number of patients with oligometastatic disease may benefit from an aggressive approach which includes surgical resection.
The aim of this systematic review is to present the published evidence on the surgical management of PDAC isolated liver metastases, synchronous and metachronous; and compare the outcomes to the current standard of care (palliative treatment).
A systematic literature search was performed for studies reporting outcomes of resection of isolated liver metastases in patients with PDAC, in either a synchronous or metachronous setting, according to the Preferred Reporting Items for Systematic Review and Meta-Analyses. Synchronous lesions were defined those appearing within 6 mo of the primary diagnosis, whilst metachronous those diagnosed after 6 mo. The primary endpoint for this systematic review was median overall survival in PDAC patients with synchronous or metachronous isolated liver metastases treated with either surgical resection or an alternative treatment modality, for example chemotherapy. Secondary outcomes included disease free survival, peri-operative morbidity and mortality.
The literature search identified a total of 356 studies, of which 31 full-text articles were screened and of these 10 articles were suitable for inclusion with a total of 449 patients. Nine studies reported outcomes of surgical resection for synchronous isolated liver metastases and 4 reported outcomes for resection of metachronous metastases (3 studies reported outcomes for both).
In conclusion, the evidence on surgical management of PDAC isolated liver metastases is scarce and inconclusive. A survival benefit may exist in selected metachronous cases when disease biology has been tested with time and systemic treatment. Survival benefit is less clear in synchronous cases; however an approach with neoadjuvant treatment and consideration of resection in some selected cases may confer some benefit.
Future studies should focus on pathways for selection of cases that may benefit from an aggressive approach, including patient selection, tumour genetic testing and individualised systemic treatment, as well as novel markers for treatment response.