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Not yet recruiting NCT07259681

Gut Microbiome in Gynecological Cancer Patients With Pelvic Toxicity: Controls Versus Ozone Treatment. (MicrOzoGineTox)

— Observational Pelvic Toxicity Radiation Toxicity Chemotherapy Toxicity Gynecological Tumors

For patients and families

In plain language

An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.

What is being studied
This is an observational study: the protocol does not assign a study treatment.
Who it may be relevant to
Registry conditions: Pelvic Toxicity, Radiation Toxicity, Chemotherapy Toxicity, Gynecological Tumors. Basic parameters: from 18 years · Female.
What needs checking
Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
Where it takes place
Spain
Next step
Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →

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Official title

Intestinal Microbiome Profiles in Women With Gynecological Tumors and Pelvic Toxicity Secondary to Radiotherapy and Chemotherapy: Comparison With Controls and Effect of Rectal Ozone Treatment.

Overview

Patients treated for gynecological tumors with radiotherapy (RT) and/or chemotherapy (CT) frequently develop pelvic toxicity (TPIRQT), a condition that can become persistent, progressive, and refractory to standard treatments. This toxicity, affecting the rectum (proctitis), bladder (cystitis), and vagina (mucositis), severely deteriorates quality of life. Standard options for refractory cases are limited; at our center, rectal ozone therapy is used with high rates of symptomatic improvement (66-75%). Emerging evidence suggests a link between gut microbiota and the development of TPIRQT. However, it is unknown how rectal ozone therapy may influence the gut microbiome or if this modulation is part of its therapeutic mechanism. This prospective observational study will investigate the potential relationship between gut microbiome profiles (composition and diversity), the presence and severity of TPIRQT, and the response to rectal ozone therapy.

Detailed description

Patients treated for gynecological tumors with radiotherapy (RT) and/or chemotherapy (CT) frequently develop pelvic toxicity (TPIRQT), a condition that can become persistent, progressive, and refractory to standard treatments. This toxicity, affecting the rectum (proctitis), bladder (cystitis), and vagina (mucositis), severely deteriorates quality of life. Standard options for refractory cases are limited; at our center, rectal ozone therapy is used with high rates of symptomatic improvement (66-75%). Emerging evidence suggests a link between gut microbiota and the development of TPIRQT. However, it is unknown how rectal ozone therapy may influence the gut microbiome or if this modulation is part of its therapeutic mechanism. This prospective observational study will investigate the potential relationship between gut microbiome profiles (composition and diversity), the presence and severity of TPIRQT, and the response to rectal ozone therapy.

Primary outcome measures

  • Comparison of gut microbiome profile (composition and diversity) between TPIRQT and Control groups [Time frame: Baseline (single time point for controls, pre-ozone for cases)]
  • Change in gut microbiome profile (composition and diversity) in patients with TPIRQT after rectal ozone therapy. [Time frame: Baseline (pre-ozone therapy) , 4 Months (post-ozone therapy)]
  • Correlation of gut microbiome profile with grade of pelvic toxicity. [Time frame: Baseline (for Control group); Baseline, 4 Months (for TPIRQT group).]
Secondary outcome measures (3)
  • Correlation of gut microbiome profile with health-related quality of life (HRQoL). [Time frame: Baseline (for Control group); Baseline, 4 Months (for TPIRQT group).]
  • Correlation of gut microbiome profile with anxiety and depression levels. [Time frame: Baseline (for Control group); Baseline, 4 Months (for TPIRQT group).]
  • Correlation of gut microbiome profile with biochemical markers of oxidative stress and inflammation. [Time frame: Baseline (for Control group); Baseline, 4 Months (for TPIRQT group).]

Eligibility criteria

Inclusion Criteria for all patients (Cases and Controls):

  • Adult women (>=18 years).
  • Diagnosed with gynecological tumors (any location and stage).
  • Previously treated with radiotherapy and/or chemotherapy.
  • Must accept and sign the specific informed consent for this study.

Additional Inclusion Criteria for inclusion in the TPIRQT Group (Cases):

  • Must present chronic TPIRQT with >= 3 months of duration after habitual symptomatic treatment.
  • Must have a toxicity Grade of 2 (moderate symptoms, limiting instrumental ADL) or higher, according to the CTCAE v.5.0 scale.

Exclusion Criteria for all patients (Cases and Controls):

  • Not meeting all inclusion criteria.
  • Presence of active inflammatory bowel disease (e.g., Crohn's Disease, Ulcerative Colitis) or a history of major gastrointestinal resection (excluding appendectomy) that could significantly alter gut anatomy and microbiota.
  • Any uncontrolled intercurrent illness or psychiatric condition that, in the investigator's opinion, would limit compliance with study requirements or interfere with the interpretation of results.
  • Unwillingness or inability to provide written informed consent for study participation.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Observational model
Case-control

Study locations

Spain · 2 centers
  • Hospital Universitario de Gran Canaria Dr. Negrín, (FIISC) — Las Palmas de Gran Canaria
  • Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias - Universid — San Cristóbal de La Laguna

Publications

  • Clavo B, Canovas-Molina A, Ramallo-Farina Y, Federico M, Rodriguez-Abreu D, Galvan S, Ribeiro I, Marques da Silva SC, Navarro M, Gonzalez-Beltran D, Diaz-Garrido JA, Cazorla-Rivero S, Rodriguez-Esparragon F, Serrano-Aguilar P. Effects of Ozone Treatment on Health-Related Quality of Life and Toxicity Induced by Radiotherapy and Chemotherapy in Symptomatic Cancer Survivors. Int J Environ Res Public PMID 36674232
  • Clavo B, Navarro M, Federico M, Borrelli E, Jorge IJ, Ribeiro I, Rodriguez-Melcon JI, Carames MA, Santana-Rodriguez N, Rodriguez-Esparragon F. Long-Term Results with Adjuvant Ozone Therapy in the Management of Chronic Pelvic Pain Secondary to Cancer Treatment. Pain Med. 2021 Sep 8;22(9):2138-2141. doi: 10.1093/pm/pnaa459. No abstract available. PMID 33738491
  • Clavo B, Navarro M, Federico M, Borrelli E, Jorge IJ, Ribeiro I, Rodriguez-Melcon JI, Carames MA, Santana-Rodriguez N, Rodriguez-Esparragon F. Ozone Therapy in Refractory Pelvic Pain Syndromes Secondary to Cancer Treatment: A New Approach Warranting Exploration. J Palliat Med. 2021 Jan;24(1):97-102. doi: 10.1089/jpm.2019.0597. Epub 2020 May 5. PMID 32379556
  • Clavo B, Santana-Rodriguez N, Llontop P, Gutierrez D, Ceballos D, Mendez C, Rovira G, Suarez G, Rey-Baltar D, Garcia-Cabrera L, Martinez-Sanchez G, Fiuza D. Ozone Therapy in the Management of Persistent Radiation-Induced Rectal Bleeding in Prostate Cancer Patients. Evid Based Complement Alternat Med. 2015;2015:480369. doi: 10.1155/2015/480369. Epub 2015 Aug 18. PMID 26357522
  • Clavo B, Ceballos D, Gutierrez D, Rovira G, Suarez G, Lopez L, Pinar B, Cabezon A, Morales V, Oliva E, Fiuza D, Santana-Rodriguez N. Long-term control of refractory hemorrhagic radiation proctitis with ozone therapy. J Pain Symptom Manage. 2013 Jul;46(1):106-12. doi: 10.1016/j.jpainsymman.2012.06.017. Epub 2012 Oct 26. PMID 23102757
  • Wang A, Ling Z, Yang Z, Kiela PR, Wang T, Wang C, Cao L, Geng F, Shen M, Ran X, Su Y, Cheng T, Wang J. Gut microbial dysbiosis may predict diarrhea and fatigue in patients undergoing pelvic cancer radiotherapy: a pilot study. PLoS One. 2015 May 8;10(5):e0126312. doi: 10.1371/journal.pone.0126312. eCollection 2015. PMID 25955845
  • Wang L, Wang X, Zhang G, Ma Y, Zhang Q, Li Z, Ran J, Hou X, Geng Y, Yang Z, Feng S, Li C, Zhao X. The impact of pelvic radiotherapy on the gut microbiome and its role in radiation-induced diarrhoea: a systematic review. Radiat Oncol. 2021 Sep 25;16(1):187. doi: 10.1186/s13014-021-01899-y. PMID 34563216
  • Li L, Yang Z, Yi Y, Song Y, Zhang W. Gut microbiota and radiation-induced injury: mechanistic insights and microbial therapies. Gut Microbes. 2025 Dec;17(1):2528429. doi: 10.1080/19490976.2025.2528429. Epub 2025 Jul 6. PMID 40618373

Identifiers

NCT: NCT07259681 · 2025-436-1 · PIFIISC25/52 · CIGC'25/26

Primary sources (government registries)

View this study on ClinicalTrials.gov ↗