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

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.

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.

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.

Inclusion Criteria for all patients (Cases and Controls):

1. Adult women (>=18 years).

2. Diagnosed with gynecological tumors (any location and stage).

3. Previously treated with radiotherapy and/or chemotherapy.

4. Must accept and sign the specific informed consent for this study.

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

5. Must present chronic TPIRQT with >= 3 months of duration after habitual symptomatic treatment.

6. 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):

1. Not meeting all inclusion criteria.
2. 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.
3. 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.
4. Unwillingness or inability to provide written informed consent for study participation.