Individuality and generality of intratumoral microbiome in the three most prevalent gynecological malignancies: an observational study

Growing evidence have indicated the crucial role of intratumor microbiome in a variety of solid tumor. However, the intratumoral microbiome in gynecological malignancies is largely unknown. In the present study, a total of 90 <i>Han</i> patients, including 30 patients with cancer in cervix, ovary, and endometrium each were enrolled, the composition of intratumoral microbiome was assessed by 16S rDNA amplicon high throughput sequencing. We found that the diversity and metabolic potential of intratumoral microbiome in all three cancer types were very similar. Furthermore, all three cancer types shared a few taxa that collectively take up high relative abundance and positive rate, including <i>Pseudomonas sp</i>., Comamonadaceae <i>gen. sp</i>., <i>Bradyrhizobium sp</i>., <i>Saccharomonospora sp</i>., <i>Cutibacterium acnes</i>, <i>Rubrobacter sp</i>., <i>Dialister micraerophilus</i>, and <i>Escherichia coli</i>. Additionally, <i>Haemophilus parainfluenzae</i> and <i>Paracoccus sp</i>. in cervical cancer, <i>Pelomonas sp</i>. in ovarian cancer, and <i>Enterococcus faecalis</i> in endometrial cancer were identified by LDA to be a representative bacterial strain. In addition, in cervical cancer patients, alpha-fetoprotein (AFP) (correlation coefficient = -0.3714) was negatively correlated (<i>r</i> = 0.4, 95% CI: 0.03 to 0.7) with <i>Rubrobacter sp</i>. and CA199 (correlation coefficient = 0.3955) was positively associated (<i>r</i> = 0.4, 95% CI: 0.03 to 0.7) with <i>Saccharomonospora sp</i>.. In ovarian cancer patients, CA125 (correlation coefficient = -0.4451) was negatively correlated (<i>r</i> = -0.4, 95% CI: -0.7 to -0.09) with <i>Porphyromonas sp.</i>. In endometrial cancer patients, CEA (correlation coefficient = -0.3868) was negatively correlated (<i>r</i> = -0.4, 95% CI: -0.7 to -0.02) with <i>Cutibacterium acnes</i>. This study promoted our understanding of the intratumoral microbiome in gynecological malignancies.IMPORTANCEIn this study, we found the compositional spectrum of tumor microbes among gynecological malignancies were largely similar by sharing a few taxa and differentiated by substantial species owned uniquely. Certain species, mostly unreported, were identified to be associated with clinical characteristics. This study prompted our understanding of gynecological malignancies and offered evidence for tumor microbes affecting tumor biology among cancers in the female reproductive system.