Recent research has uncovered a significant link between microbiota and antitumour immunity, highlighting the role of dendritic cell migration in patients with advanced cancers. The study focused on individuals diagnosed with advanced Non-Small Cell Lung Cancer (NSCLC) and Gastric Cancer (GC) who underwent treatment with PD-1 blockade monotherapy, specifically using the drugs nivolumab or pembrolizumab. Conducted in Japan, the study enrolled a total of 50 patients across two cohorts between March 2017 and September 2018.
The research evaluated two independent cohorts: the discovery cohort, which consisted of patients who received PD-1 blockade therapy from March to December 2017, and the validation cohort, which included patients treated from January to September 2018. In addition, patients with Head and Neck Squamous Cell Carcinoma (HNSCC) who received similar treatment from June 2022 to October 2023 were also analyzed. Participants who had received antibiotics or microbiome intervention therapies within one month prior to treatment initiation were excluded from the study.
In this trial, the researchers specifically classified patients based on their treatment responses. Those achieving a complete or partial response, or maintaining stable disease for over six months, were identified as responders. This classification included patients from the validation cohort, where 21 patients were included, with 7 having NSCLC and 14 with GC.
To assess the immunological landscape, various analyses were performed on tumor-infiltrating lymphocytes (TILs) isolated from the patients’ tumor samples. These samples were subjected to multiple immunological evaluations, providing insights into the interaction between microbiota and immune responses in cancer treatment.
The study involved comprehensive methodologies, including the collection of stool samples prior to initial treatment and the extraction of DNA from these samples for microbiota analysis. The researchers utilized techniques such as flow cytometry and quantitative PCR to comprehensively analyze immune cell populations and their interactions with the microbiota. This entailed evaluating the expression of various markers and understanding the diversity of the microbiome in relation to treatment outcomes.
Furthermore, the study explored the potential for microbiota-driven influences on the efficacy of PD-1 blockade therapies. The analysis included samples from patients in the MONSTAR cohort, which provided additional data points from different cancer types, including advanced melanoma and renal cell carcinoma.
The findings suggest a complex relationship between the microbiome and the immune system, emphasizing the importance of understanding these dynamics in the context of cancer therapy. The research aims to pave the way for personalized treatment approaches that consider the microbiota’s role in enhancing antitumor immunity.
In conclusion, this investigation into microbiota-driven antitumour immunity offers promising insights for future cancer therapies, potentially leading to more effective treatment strategies that harness the power of the microbiome. As research continues, the hope is to translate these findings into clinical practice, providing better outcomes for patients battling advanced cancers.
