How participants in cancer trials are chosen: ethics and conflicting interests

Informed consent in cancer clinical drug trials in China: a narrative literature review of the past 20 years

BACKGROUND

Although the number of cancer clinical drug trials is increasing rapidly in China, issues concerning informed consent in this research context are understudied. By performing a narrative literature review, we aim to describe the current situation and identify the most salient challenges affecting informed consent in cancer clinical drug trials among adult patients in China since 2000.

METHODS

We searched Web of Science (WOS), PubMed, Scopus, EMBASE, the Cochrane Library databases, China National Knowledge Infrastructure (CNKI), China Biomedical Literature Database on Disc (CBMdisc), Chinese Scientific Journals Fulltext Database (CQVIP), and WANFANG Data to identify relevant publications since 2000. Data were extracted by three reviewers on six items pertaining to study type, theme, and challenges.

RESULTS

We identified 37 unique manuscripts, from which 19 full texts were obtained and six were included in the review. All six studies were published in Chinese journals, and the publication years of the majority (five out of six) of the studies were 2015 or later. The authors of the six studies were all from clinical departments or ethical review committees at five hospitals in China. All of the included publications were descriptive studies. Publications reported challenges related to the following aspects of informed consent: information disclosure, patient understanding, voluntariness, authorization, and procedural steps.

CONCLUSION

Based on our analysis of publications over the past two decades, there are currently frequent challenges related to various aspects of informed consent in cancer clinical drug trials in China. Furthermore, only a limited number of high-quality research studies on informed consent in cancer clinical drug trials in China are available to date. Efforts toward improvement of informed consent practice, in the form of guidelines or further regulations in China, should draw on both experience from other countries and high-quality local evidence.

Hepatocellular carcinoma

Liver cancer remains a global health challenge, with an estimated incidence of >1 million cases by 2025. Hepatocellular carcinoma (HCC) is the most common form of liver cancer and accounts for ~90% of cases. Infection by hepatitis B virus and hepatitis C virus are the main risk factors for HCC development, although non-alcoholic steatohepatitis associated with metabolic syndrome or diabetes mellitus is becoming a more frequent risk factor in the West. Moreover, non-alcoholic steatohepatitis-associated HCC has a unique molecular pathogenesis. Approximately 25% of all HCCs present with potentially actionable mutations, which are yet to be translated into the clinical practice. Diagnosis based upon non-invasive criteria is currently challenged by the need for molecular information that requires tissue or liquid biopsies. The current major advancements have impacted the management of patients with advanced HCC. Six systemic therapies have been approved based on phase III trials (atezolizumab plus bevacizumab, sorafenib, lenvatinib, regorafenib, cabozantinib and ramucirumab) and three additional therapies have obtained accelerated FDA approval owing to evidence of efficacy. New trials are exploring combination therapies, including checkpoint inhibitors and tyrosine kinase inhibitors or anti-VEGF therapies, or even combinations of two immunotherapy regimens. The outcomes of these trials are expected to change the landscape of HCC management at all evolutionary stages.

Veterinary oncology clinical trials: design and implementation

There has been a recent increase in interest among veterinarians and the larger biomedical community in the evaluation of novel cancer therapies in client-owned (pet) animals with spontaneous cancer. This includes novel drugs designed to be veterinary therapeutics, as well as agents for which data generated in animals with tumors may inform human clinical trial design and implementation. An understanding of the process involved in moving a therapeutic agent through the stages of clinical evaluation is critical to the successful implementation of clinical investigations, as well as interpretation of the veterinary oncology literature. This review outlines considerations in the design and conduct of the various phases of oncology clinical trials, along with recent adaptations/modifications of these basic designs that can enhance the generation of timely and meaningful clinical data.

Casearin X exhibits cytotoxic effects in leukemia cells triggered by apoptosis

Clerodane diterpenes have demonstrated cytotoxic, antiplasmodial and anti-ulcer properties. In the present work, we determined the cytotoxic effect of casearin L (Cas L), O (Cas O) and X (Cas X) and (-)-hardwickiic acid isolated from Casearia sylvestris leaves, and investigated the underlying mechanisms involved in in vitro cell death induced by Cas X in HL-60 leukemia cells (0.7, 1.5 and 3.0μM). Cytotoxicity tests demonstrated that Cas X was the most active compound studied, showing greater cytotoxic effects against CEM and HL-60 lines (IC(50) of 0.4μM) and human peripheral blood mononuclear cells (PBMC, IC(50) of 1.2μM). After 24h exposure, Cas X caused a decrease in 5-bromo-20-deoxyuridine (BrdU) incorporation (36.6 and 24.5% labeling at 0.7 and 1.5μM, respectively), reduction in viability, and increase in apoptotic and necrotic leukemia cells in a dose-dependent manner evidenced by the trypan blue and AO/EB (acridine orange/ethidium bromide) assays. Moreover, Cas X-treated cells exhibited nuclear fragmentation and cytoplasmic vacuolization depending on the concentration tested. These characteristics of apoptosis or secondary necrosis were confirmed by flow cytometry which revealed DNA fragmentation, phosphatidylserine externalization, activation of the effector caspases 3/7 and mitochondrial depolarization. We then found evidence that Cas X causes cell death via apoptotic pathways, corroborating the potential of casearins as compounds with promising antitumor-related properties.

Towards optimised information about clinical trials; identification and validation of key issues in collaboration with cancer patient advocates

Clinical trials are crucial to improve cancer treatment but recruitment is difficult. Optimised patient information has been recognised as a key issue. In line with the increasing focus on patients' perspectives in health care, we aimed to study patients' opinions about the written information used in three clinical trials for breast cancer. Primary data collection was done in focus group interviews with breast cancer patient advocates. Content analysis identified three major themes: comprehensibility, emotions and associations, and decision making. Based on the advocates' suggestions for improvements, 21 key issues were defined and validated through a questionnaire in an independent group of breast cancer patient advocates. Clear messages, emotionally neutral expressions, careful descriptions of side effects, clear comparisons between different treatment alternatives and information about the possibility to discontinue treatment were perceived as the most important issues. Patients' views of the information in clinical trials provide new insights and identify key issues to consider in optimising future written information and may improve recruitment to clinical cancer trials.

Ethics of cancer gene transfer clinical research

Cancer gene transfer is a relatively novel intervention strategy. In part because of this novelty, trials often present greater uncertainties than those investigating more conventional approaches. In the following review, I examine how this greater uncertainty might affect how clinical studies are designed, when they are initiated, their degree of risk, and whether such risk can be justified in terms of therapeutic benefit. The review also discusses two other ethical issues presented by gene transfer clinical research: fairness in subject selection and communications with the public. I conclude with a series of recommendations directed toward researchers, policymakers, and ethics committee members.