It is increasingly recognized that microbes that reside in and on human body sites play major roles in modifying the pathogenesis of several diseases including cancer. However, specific microbes or microbial communities that can be mechanistically linked to cervical carcinogenesis remain largely unexplored. The purpose of the study was to examine the association between cervical microbiota and high-grade cervical intraepithelial neoplasia (CIN 2+) in women infected with high-risk (HR) human papillomaviruses (HPVs) and to assess whether the cervical microbiota are associated with oxidative DNA damage as indicated by the presence of cervical cells positive for 8-hydroxy-2′-deoxyguanosine. Study included 340 women diagnosed with CIN 2+ (cases) and 90 diagnosed with CIN 1 (non-cases). Microbiota composition was determined by Illumina sequencing of the 16S rRNA gene amplified from DNA extracted from cervical mucus samples. Measures of alpha/beta-diversity were not associated with either CIN severity or oxidative DNA damage. However, a cervical mucosal community type (CT) dominated by L. iners and unclassified Lactobacillus spp. was associated with CIN 2+ (OR=3.48, 95% CI: 1.27–9.55). Sequence reads mapping to Lactobacillaceae, Lactobacillus, L. reuteri and several sub-genus level Lactobacillus OTUs were also associated with CIN 2+ when examined independently (effect size >2.0; p < 0.05). Our 16S rRNA sequencing results need confirmation in independent studies using whole-genome shotgun sequencing and that would allow sharpening the suggested associations at finer taxonomic levels. Our results provide little evidence that DNA oxidative damage mediates the effect of the microbiome on the natural history of HPV infection and CIN severity.

Obesity has been associated with an increased risk of postmenopausal breast cancer. Adipokines and systemic inflammation have been hypothesized to underlie this association. In a case-control study nested within the Multiethnic Cohort, conditional logistic regression was used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) for postmenopausal breast cancer associated with prediagnostic levels of serum leptin, adiponectin, the leptin:adiponectin ratio, and C-reactive protein (CRP). The 706 cases and 706 controls were matched on ethnicity, location (Hawaii or Los Angeles), birth year, date and time of blood draw, hours fasting prior to blood draw, and hormone replacement therapy use at blood draw. Higher circulating levels of leptin (OR Q4 vs. Q1=1.94 [1.37-2.75]; Ptrend = < 0.001), the leptin:adiponectin ratio (OR=1.91 [1.36-2.68]; Ptrend = 0.005), and CRP (OR=1.41 [1.01-1.96]; Ptrend = 0.014) were associated with an increased risk of postmenopausal breast cancer. The positive associations for these markers remained after adjustment for body mass index (BMI). No associations were detected for adiponectin. These data suggest that adipokines and systemic inflammation may be associated with the risk of postmenopausal breast cancer independently of BMI. Further prospective studies examining the role of adipokines and inflammatory processes in the etiology of postmenopausal breast cancer are warranted.