Lauren E. Colbert

Cervical and Tumor-Associated Microbiomes in Botswana Women With and Without HIV With Carcinoma of the Cervix Before and After Definitive Chemoradiation

PURPOSE Cervical cancer remains a significant public health concern globally and particularly in sub-Saharan Africa, where high rates of HIV infection exacerbate cervical cancer incidence. Understanding the cervical microbiome and its role in cancer progression is essential, especially in regions where both cervical cancer incidence and HIV prevalence are high. This study aimed to characterize the cervical microbiome in women living with HIV (WLWH) and HIV-negative women with squamous cell carcinoma of the cervix in Botswana, compare the microbiome between before and after chemoradiation therapy (CRT) in WLWH, and assess the prognostic value of specific microbial taxa for overall survival (OS) in WLWH. PATIENTS AND METHODS Cervical samples were collected from women with cervical cancer presenting to one hospital in 2018-2019. Patients' clinical data, including HIV status, were recorded. Microbial composition was analyzed using 16S rRNA gene sequencing. Microbiome diversity and composition were evaluated using alpha and beta diversity metrics. Differential microbial abundance was analyzed using linear discriminant analysis effect size. The association between microbial taxa and OS was explored using Cox proportional hazards regression. RESULTS WLWH (n = 42) had a significantly lower Pielou evenness index than HIV-negative women (n = 11; 0.6 v 0.7, P = .02), suggesting a more imbalanced microbiome in WLWH. WLWH had higher levels of Parvimonas and members of the Corynebacteriaceae and Micrococcaceae families, suggesting a shift toward a more pathogenic microbiome. In WLWH, CRT did not significantly alter overall microbial diversity. However, Lactobacillus and Sutterella were enriched before treatment, reflecting a less pathogenic microbiome, whereas Ruminococcus and Phascolarctobacterium and the families Caulobacterales and Flavobacteriia were enriched after treatment, reflecting microbial adaptations to the altered immune and treatment environment. Notably, higher levels of Flavobacteriia after CRT were independently associated with worse OS in WLWH. CONCLUSION Microbiome profiles differ between WLWH and HIV-negative women with cervical cancer in Botswana. The microbiome might have prognostic significance. Future research is needed to better understand the significance of the microbiota in cervical cancer progression and treatment outcomes and the potential role of microbiome-targeted interventions.

Linking Microbiome Diversity and Immune Profiles in Ethiopian Patients With Cervical Cancer

PURPOSE This study investigates the interplay between T-cell receptor (TCR) immune characteristics and microbiome profiles to explore the relationship between immune diversity and microbial composition in cervical samples from Ethiopia. METHODS Cervical specimens were collected from patients at Tikur Anbessa Specialized Hospital in Addis Ababa, and rural Butajira, south-central Ethiopia. Patient data, including age, human papillomavirus status, pathology, and TCR immune characteristics, were analyzed with a focus on the interactions between TCR profiles and microbiome compositions in malignant samples. RESULTS Three distinct TCR profiles were identified: Group 1 (TCR active) exhibited features of active immune engagement, including high diversity, clonal expansion, and repertoire richness. Group 2 (TCR restricted) showed reduced TCR diversity and expansion, suggesting a restricted repertoire. Group 3 (TCR balanced) had moderate diversity and clonal activity. TCR repertoire groups were linked with microbial diversity, with Group 1 (TCR active) showing the highest number of microbes (high operational taxonomic units and microbial diversity). Maximum TCR clonal expansion positivity associated with microbial richness, while Group 3 (TCR balanced) was linked to reduced microbial alpha diversity. Taxonomic analysis revealed specific organisms enriched in TCR repertoire group. CONCLUSION Variations in TCR profiles are linked to distinct microbial environments in cervical cancer with greater microbial richness in patients with greater maximum productive frequency. These findings underscore the interplay between TCR diversity, microbiome composition, and malignancy, offering insights into the potential implications for microbiome-targeted therapies and prognostic biomarkers in cervical cancer.

Protocol for culturing patient-derived organoids of cervical cancer

Herein, we present a protocol for culturing patient-derived organoids (PDOs) of cervical cancer that includes workflows for tumor biopsy/resection tissue and cytobrush-sampled cells. We describe steps for PDO culture initiation, including rinsing, gentle dissociation, Lymphoprep separation, and cell assessment, as well as seeding cells from surgical and cytobrush tissue digestion. We then provide guidance on PDO maintenance and passage and techniques for producing conditioned medium. Overall, this protocol serves as a valuable guide for establishing and maintaining cervical cancer PDOs. For complete details on the use and execution of this protocol, please refer to Colbert et al.

Feasibility of a novel non-invasive swab technique for serial whole-exome sequencing of cervical tumors during chemoradiation therapy

Background Clinically relevant genetic predictors of radiation response for cervical cancer are understudied due to the morbidity of repeat invasive biopsies required to obtain genetic material. Thus, we aimed to demonstrate the feasibility of a novel noninvasive cervical swab technique to (1) collect tumor DNA with adequate throughput to (2) perform whole-exome sequencing (WES) at serial time points over the course of chemoradiation therapy (CRT). Methods Cervical cancer tumor samples from patients undergoing chemoradiation were collected at baseline, at week 1, week 3, and at the completion of CRT (week 5) using a noninvasive swab-based biopsy technique. Swab samples were analyzed with whole-exome sequencing (WES) with mutation calling using a custom pipeline optimized for shallow whole-exome sequencing with low tumor purity (TP). Tumor mutation changes over the course of treatment were profiled. Results 216 samples were collected and successfully sequenced for 70 patients (94% of total number of tumor samples collected). A total of 33 patients had a complete set of samples at all four time points. The mean mapping rate was 98% for all samples, and the mean target coverage was 180. Estimated TP was greater than 5% for all samples. Overall mutation frequency decreased during CRT but mapping rate and mean target coverage remained at >98% and >180 reads at week 5. Conclusion This study demonstrates the feasibility and application of a noninvasive swab-based technique for WES analysis which may be applied to investigate dynamic tumor mutational changes during treatment to identify novel genes which confer radiation resistance.

Metagenomes of rectal swabs in larger, advanced stage cervical cancers have enhanced mucus degrading functionalities and distinct taxonomic structure

AbstractBackgroundGut microbiome community composition differs between cervical cancer (CC) patients and healthy controls, and increased gut diversity is associated with improved outcomes after treatment. We proposed that functions of specific microbial species adjoining the mucus layer may directly impact the biology of CC.MethodMetagenomes of rectal swabs in 41 CC patients were examined by whole-genome shotgun sequencing to link taxonomic structures, molecular functions, and metabolic pathway to patient’s clinical characteristics.ResultsSignificant association of molecular functions encoded by the metagenomes was found with initial tumor size and stage. Profiling of the molecular function abundances and their distributions identified 2 microbial communities co-existing in each metagenome but having distinct metabolism and taxonomic structures. Community A (ClostridiaandProteobacteriapredominant) was characterized by high activity of pathways involved in stress response, mucus glycan degradation and utilization of degradation byproducts. This community was prevalent in patients with larger, advanced stage tumors. Conversely, community B (Bacteroidiapredominant) was characterized by fast growth, active oxidative phosphorylation, and production of vitamins. This community was prevalent in patients with smaller, early-stage tumors.ConclusionsIn this study, enrichment of mucus degrading microbial communities in rectal metagenomes of CC patients was associated with larger, more advanced stage tumors.

Tumor-resident Lactobacillus iners confer chemoradiation resistance through lactate-induced metabolic rewiring

Tumor microbiota can produce active metabolites that affect cancer and immune cell signaling, metabolism, and proliferation. Here, we explore tumor and gut microbiome features that affect chemoradiation response in patients with cervical cancer using a combined approach of deep microbiome sequencing, targeted bacterial culture, and in vitro assays. We identify that an obligate L-lactate-producing lactic acid bacterium found in tumors, Lactobacillus iners, is associated with decreased survival in patients, induces chemotherapy and radiation resistance in cervical cancer cells, and leads to metabolic rewiring, or alterations in multiple metabolic pathways, in tumors. Genomically similar L-lactate-producing lactic acid bacteria commensal to other body sites are also significantly associated with survival in colorectal, lung, head and neck, and skin cancers. Our findings demonstrate that lactic acid bacteria in the tumor microenvironment can alter tumor metabolism and lactate signaling pathways, causing therapeutic resistance. Lactic acid bacteria could be promising therapeutic targets across cancer types.

Human Papilloma Virus Circulating Cell-Free DNA Kinetics in Patients with Cervical Cancer Undergoing Definitive Chemoradiation

Abstract Purpose: Human papillomavirus (HPV) is a significant cause of cervical cancer. We hypothesized that detecting viral cell-free HPV DNA (cfDNA) before, during, and after chemoradiation (chemoRT) could provide insights into disease extent, clinical staging, and treatment response. Experimental Design: A total of 66 patients with locally advanced cervical cancer were enrolled between 2017 and 2023, with 49 receiving standard-of-care treatment and 17 participating in a clinical trial combining a therapeutic HPV vaccine (PDS0101; IMMUNOCERV). Plasma was collected at baseline, weeks 1, 3, and 5 of chemoRT, and 3 to 4 months after chemoRT. HPV cfDNA was quantified using droplet digital PCR targeting the HPV E6/E7 oncogenes of 13 high-risk types. MRI was performed at baseline and before brachytherapy. Results: The median follow-up was 23 months, with recurrence-free survival (RFS) of 78.4% at 2 years. Baseline nodal disease extent correlated with HPV cfDNA levels. HPV cfDNA levels peaked in week 1 of radiation and decreased through treatment. Patients receiving the PDS0101 vaccine had a higher rate of undetectable HPV type 16 cfDNA compared with those who received standard-of-care therapy. HPV cfDNA clearance correlated with better 2-year RFS (92.9% vs. 30%, log-rank; P = 0.0067). The strongest predictor of RFS was HPV cfDNA clearance in follow-up achieving a concordance index score of 0.83, which improved when combined with MRI response (concordance index, 0.88). Conclusions: HPV cfDNA levels change dynamically during chemoRT. HPV cfDNA levels at follow-up predict RFS, and delivery of therapeutic HPV vaccine with chemoRT was linked to rapid HPV cfDNA decline. Monitoring HPV cfDNA during and after chemoRT may guide tailoring of personalized treatment.

Exploratory analysis of the cervix tumoral HPV antigen-specific T-cell repertoire during chemoradiation and after brachytherapy

Chemoradiation (CRT) may modulate the immune milieu as an in-situ vaccine. Rapid dose delivery of brachytherapy has unclear impact on T-cell repertoires. HPV-associated cancers express viral oncoproteins E6/E7, which enable tracking antigen/tumor-specific immunity during CRT. Thirteen cervical cancer patients on a multi-institutional prospective protocol from 1/2020-1/2023 underwent standard-of-care CRT with pulsed-dose-rate brachytherapy boost (2 fractions). Cervix swabs at various timepoints underwent multiplex DNA deep sequencing of the TCR-β/CDR3 region with immunoSEQ. Separately, HPV-responsive T-cell clones were also expanded ex vivo. Statistical analysis was via Mann-Whitney-U. TCR productive clonality, templates, frequency, or rearrangements increased post-brachytherapy in 8 patients. Seven patients had E6/E7-responsive evolution over CRT with increased productive templates (ranges: 1.2-50.2 fold-increase from baseline), frequency (1.2-1.7), rearrangements (1.2-40.2), and clonality (1.2-15.4). Five patients had HPV-responsive clonal expansion post-brachytherapy, without changes in HPV non-responsive clones. Epitope mapping revealed VDJ rearrangements targeting cervical cancer-associated antigens in 5 patients. The only two patients with disease recurrence lacked response in all metrics. A lack of global TCR remodeling correlated with worse recurrence-free survival, p = 0.04. CRT and brachytherapy alters the cervical cancer microenvironment to facilitate the expansion of specific T-cell populations, which may contribute to treatment efficacy.

Comparing long-term sexual dysfunction across different uterine cancer treatment modalities

The objective of this study was to assess differences in long-term sexual and menopausal side effects after uterine cancer treatment among treatment modalities. This is a cross-sectional study that examined women treated for uterine cancer from 2006-2018. Eligible women included those who underwent a hysterectomy/bilateral salpino-oophorectemy alone (HS), with brachytherapy (BT), or with external beam radiation therapy (EBRT). A noncancer cohort of women who underwent a hysterectomy/BSO for benign indications were also identified (non-CA). To compare outcomes, we utilized a shortened form of the female sexual function index (FSFI) and the menopause survey, which consists of 3 subscales: hot flashes, vaginal symptoms, and urinary symptoms. Demographic, comorbidity, and other treatment variables were collected. Survey totals were compared across cohorts using ANOVA tests and logistic regression. A total of 284 women completed the Menopause Survey (Non-CA 64, HS 60, BT 69, EBRT 91); 116 women reported sexual activity in the last 4 weeks and completed the FSFI (NC 32, HS 21, BT 31, EBRT 32). The mean FSFI score for the entire cohort was 11.4 (SD 4.16), which indicates poor sexual function. There was no significant difference between any cohort in the overall FSFI score (p = 0.708) or in any of the FSFI subscales (all p > 0.05). On univariate analysis, BT was associated with fewer menopausal hot flashes and vaginal symptoms compared to the non-CA cohort (p < 0.05), which did not persist on multivariable analysis. There was no significant difference in sexual dysfunction or menopausal symptoms in those treated for uterine cancer with or without adjuvant radiation. Most patients reported poor sexual function.