Changes in the cervical microbiota of cervical cancer patients after primary radio-chemotherapy

Abstract

ObjectiveSeveral recent studies have identified a potential interaction between the vaginal microbiota and gynecological cancers, but little is known about the cervical microbiota and its changes during cancer treatment. Therefore, the aim of the study was to evaluate the quantitative and qualitative changes of cervical microbiota in patients undergoing concurrent chemotherapy and radiation treatment for locally advanced cervical cancer.MethodsCervical cytobrush samples of 15 cervical patients undergoing chemoradiation treatment were collected 1 day before starting external beam radiation therapy and on the day of the last fraction of brachytherapy. After DNA extraction, 16S rRNA amplicon sequencing of the V3–V4 region was performed on the MiSeq platform, followed by data processing and statistical analyses concerning the alpha and beta diversity of 16 samples (7 samples were excluded because of incomplete sample sets).ResultsThe amount of amplicon yield after polymerase chain reaction analysis in post-radiation samples was significantly lower compared with the baseline samples (pre 31.49±24.07 ng/µl; post 1.33±1.94 ng/µl; p=0.007). A comparison of pre-treatment and post-treatment samples did not show significant differences regarding beta diversity (weighted UniFrac). There was no significant difference in alpha diversity, which is used to characterize species diversity within a particular community and takes into account both number and abundance (Shannon Diversity Index pre-treatment samples: 2.167±0.7504 (95% CI 1.54 to 2.79); post-treatment samples: 1.97±0.43 (95% CI 1.61 to 2.33); p=0.38). Interindividual differences in patients could partly explain some variation of the samples (permutational multivariate analysis of variance).ConclusionThere was a strong reduction in cervical bacterial loads after chemoradiation. Neither alpha nor beta diversity varied significantly when baseline samples were compared with post-treatment samples.

Changes in the diversity of local cervical bacteria in women with cervical cancer receiving antineoplastic treatment

“…On the other hand, Tsakmaklis et al .,[ 11 ] in 2020, evaluated by molecular methods, quantitative and qualitative changes in cervical microbiota in 8 patients undergoing chemotherapy and radiotherapy. In this study, the authors reported a considerable reduction in cervical bacterial load after chemotherapy and radiotherapy.…”

“…The changes in bacterial composition were analyzed at four stages of treatment, in contrast to what was reported by Tsakmaklis et al . [ 11 ] and Mubangizi et al . [ 20 ] Our results show that chemotherapy and brachytherapy decrease local bacterial diversity, in contrast to previous reports.…”

“…Recently, Tsakmaklis et al . [ 11 ] showed that cervical microbiota has a considerable reduction after chemoradiation. However, they did not find modifications in the composition of the cervical microbiota under antineoplastic treatment.…”

Molecular Markers to Predict Prognosis and Treatment Response in Uterine Cervical Cancer

“…During CRT, a significant decrease in the bacterial load of cervical cytobrush samples was observed, while neither alpha-nor beta-diversity significantly changed [268]. Sims et al succeeded in showing that the diversity of the gut microbiota could act as pre-dictor of the survival of cervical cancer patients after CRT.…”

The Female Reproductive Tract Microbiome—Implications for Gynecologic Cancers and Personalized Medicine

“…There are no published studies yet demonstrating an impact of the FRT microbiome on response to treatment of gynecologic cancers. Changes in the vaginal and cervical microbiome were observed following pelvic radiation therapy, a commonly used primary or adjuvant treatment for cervical and endometrial cancer [95,96]. However, possible associations between the FRT microbiome and treatment response were not assessed in these small pilot studies.…”