Resection and thermal hepatic ablation of pancreatic neuroendocrine tumor liver metastases for prolonged survival

We read with great interest the article published in BJS Open by Kjaer et al. (1). The authors conducted a retrospective study involving 108 patients with pancreatic neuroendocrine tumor liver metastases (Pan-NELM) to assess the benefit of resection and thermal hepatic ablation (THA) on the prognoses of patients with Pan-NELM. The study found that patients receiving surgery and/or THA for Pan-NELM had longer overall survival than the control group. We congratulate the authors’ efforts to provide insights into the management of patients with Pan-NELM. However, some points deserve to be addressed.

Firstly, patients’ performance status, which was a possible confounder, was not taken into consideration, although patients’ characteristics (for instance, Charlson co-morbidity index) were included. Normally, patients with poorer performance status were more likely to receive conservative treatment rather than surgery, and tended to have more dismal prognoses (2). Therefore, potential selection bias shouldn’t be overlooked since the patients were selected to undergo surgery and/or THA (3).

Besides, heterogeneity caused by long span could be further discussed via subgroup analysis, although time period was included in multivariate analysis. The authors collected patients’ records over a long-time span from 1995 to 2017. As treatment of Pan-NELM has achieved significant progress in the last decade (4,5), and the hazard ratio of surgery/THA could vary in different time periods.

Furthermore, the procedures of resection and/or THA were recommended to be included in the analysis. As stated in the article, patients underwent treatment with either a curative intent or a debulking procedure. Whether debulking and complete removal of liver metastases impacted differently on patients’ long-term survival was worth investigation in the study.

In summary, we appreciate the authors’ efforts in this remarkable article. Under the background that surgical treatment for Pan-NELM remains controversial, further researches are warranted to provide high-quality evidence.

Acknowledgments

Funding: None.

Footnote

Provenance and Peer Review: This article was a standard submission to the journal. The article did not undergo external peer review.

Conflicts of Interest: Both authors have completed the ICMJE uniform disclosure form (available at https://jgo.amegroups.com/article/view/10.21037/jgo-22-725/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Kjaer J, Stålberg P, Crona J, et al. Long-term outcome after resection and thermal hepatic ablation of pancreatic neuroendocrine tumour liver metastases. BJS Open 2021;5:zrab062. [Crossref] [PubMed]
2. Xiang JX, Lv Y, Zhang XF. Surgical treatment for neuroendocrine liver metastasis: moving ahead in controversy. Hepatobiliary Surg Nutr 2021;10:868-71. [Crossref] [PubMed]
3. Arita J, Kiritani S, Hasegawa K. Management of neuroendocrine liver metastasis: Searching for new prognostic factor and appraising repeat hepatectomy. Hepatobiliary Surg Nutr 2021;10:410-2. [Crossref] [PubMed]
4. Das S, Dasari A. Novel therapeutics for patients with well-differentiated gastroenteropancreatic neuroendocrine tumors. Ther Adv Med Oncol 2021;13:17588359211018047. [Crossref] [PubMed]
5. Cloyd JM, Ejaz A, Konda B, et al. Neuroendocrine liver metastases: a contemporary review of treatment strategies. Hepatobiliary Surg Nutr 2020;9:440-51. [Crossref] [PubMed]