The efficacy of ketamine for pain management in patients with cancer: A systematic review

Copyright © 2024 American Society of Clinical Oncology. All rights reserved.e24069 Background: Managing cancer-related pain poses significant challenges, prompting research into alternative approaches such as the study of ketamine. This systematic review aims to analyze and summarize the impact of ketamine as an adjuvant to opioid therapy for cancer-related pain. Methods: We conducted a literature review in MEDLINE, EMBASE, and Scopus, spanning from January 1, 1982, to October 20, 2022. Abstracts were screened against inclusion criteria, and eligible studies underwent a thorough full-text review. Data were extracted from the included studies, and a framework analysis approach was employed to summarize the evidence regarding ketamine's use in patients with cancer. The quality of included studies was assessed using the NIH Quality Assessment Tool for controlled intervention studies. Results: A total of 22 studies conducted between 2001 and 2019 were included, all assessed as having good quality. Three studies focusing on intrathecal administration of ketamine following oncological surgery demonstrated a substantial improvement in pain scores and a reduction in postoperative morphine requirements. Two studies exploring intramuscular use concluded that it led to improved pain scores. In contrast, three studies on subcutaneous administration and two studies on topical ketamine did not exhibit a significant impact on reducing pain scores or alleviating chemotherapy-induced peripheral neuropathy. Findings from two studies on oral administration and eight studies on intravenous administration indicated that intravenous ketamine reduced postoperative morphine requirements, while oral ketamine had no discernible effect on lowering pain scores. Conclusions: The use of intrathecal ketamine demonstrates significant improvement in post-op oncological pain and refractory cancer pain, resulting in lowered pain scores and decreased morphine requirements. Further research is essential to ascertain the extent to which incorporating ketamine with opioids in cancer pain treatment can enhance pain outcomes, especially in morphine-tolerant patients

Preclinical models of neuroendocrine neoplasia

Neuroendocrine neoplasia (NENs) are a complex and heterogeneous group of cancers that can arise from neuroendocrine tissues throughout the body and differentiate them from other tumors. Their low incidence and high diversity make many of them orphan conditions characterized by a low incidence and few dedicated clinical trials. Study of the molecular and genetic nature of these diseases is limited in comparison to more common cancers and more dependent on preclinical models, including both in vitro models (such as cell lines and 3D models) and in vivo models (such as patient derived xenografts (PDXs) and genetically-engineered mouse models (GEMMs)). While preclinical models do not fully recapitulate the nature of these cancers in patients, they are useful tools in investigation of the basic biology and early-stage investigation for evaluation of treatments for these cancers. We review available preclinical models for each type of NEN and discuss their history as well as their current use and translation