Investigating the diversity of intratumoral microbiota in high-grade serous ovarian cancer with varying platinum sensitivity

Background: Ovarian cancer remains the most lethal gynecological malignancy. However, no studies have investigated the differences in intratumoral microbiota among patients with varying platinum sensitivity. This study aims to explore the intratumoral microbiota of ovarian cancer in relation to different sensitivities to platinum-based chemotherapy. Methods: Tumor samples were collected from ovarian cancer patients exhibiting different platinum-sensitive statuses and subjected to microbiome (16S rRNA gene sequencing) analyses. Following DNA extraction and PCR amplification, library construction and sequencing were performed. The differences in intratumoral microbiota across various groups were analyzed both individually and collectively using a range of bioinformatics approaches. Results: A total of 22 patients with high-grade serous ovarian cancer participated in this study, including 6 from the platinum-sensitive recurrent group, 8 from the platinum-resistant recurrent group, and 8 from the platinum-refractory group. Bacterial diversity within the intratumoral microbiota, phylogenetic profiles of microbial communities, as well as functional predictions and bacterial phenotypes all exhibited significant differences among these three groups. At the phylum level, Firmicutes, Actinobacteria, and Acidobacteria were significantly more abundant in the platinum-refractory group compared to both the platinum-sensitive recurrent group and the platinum-resistant recurrent group. Additionally, genera Lactococcus and Corynebacterium showed significant enrichment in the platinum-refractory group relative to both other groups. Conclusions: This study is pioneering in identifying variations in intratumoral microbiota associated with differing sensitivities to platinum therapy in ovarian cancer patients; these findings may provide valuable insights for future mechanistic research.