ASCOBT 2023: Is the Gut Microbiome a Key to Predicting Immunotherapy Response in Liver Cancer?

By: Amanda E. Ruffino, BA
Posted: Friday, August 11, 2023

Feng-Ming Spring Kong, MD, PhD, of the University of Hong Kong-Shenzhen Hospital, China, and colleagues investigated the role of the gut microbiome in predicting immunotherapy response in patients with hepatocellular carcinoma. The study, presented at the 2023 American Society of Clinical Oncology (ASCO) Breakthrough meeting (Abstract 47) in Yokohama, Japan, included 66 patients with advanced hepatocellular carcinoma who received immunotherapy for the first time—categorized as nonresponders, short responders, or long responders—based on treatment outcomes.

The researchers found a significant association between the gut microbiome’s diversity and composition with treatment response. The gut microbiome’s beta-diversity increased as treatment response improved, indicating a potential link between diverse gut bacteria and positive outcomes, according to the investigators. Of note, nonresponders had lower beta-diversity compared with short responders and long responders, suggesting its potential as a predictive factor for immunotherapy success.

In long responders, the study identified a higher abundance of the probiotic bacterium Clostridium butyricum—a Gram-positive, spore-forming bacillus capable of producing high amounts of butyric acid—which was not observed in nonresponders. This finding implies a potential mechanistic impact on enhancing antitumor immunity and contributing to durable treatment responses. The study also revealed enriched anabolic pathways, such as fatty acid biogenesis, in long responders, which may play a role in improving the effectiveness of immunotherapy.

According to the study authors, these findings have significant clinical implications. By analyzing the gut microbiome before immunotherapy, clinicians may be able to predict which patients are more likely to respond to treatment, leading to personalized therapeutic approaches. Moreover, the enrichment of Clostridium butyricum suggests potential avenues for novel therapeutic interventions targeting the gut microbiome to enhance immunotherapy outcomes. However, further verification and larger studies are necessary to validate these findings in patients with hepatocellular carcinoma.

Disclosure: For full disclosures of study authors, visit meetings.asco.org.

2023 ASCO Breakthrough

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