An observational study in Locally Advanced Cervical Cancer and Vitamin D Concentration, sponsored by University of Kragujevac. Recruiting at 1 site in Serbia. Open to female participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-08-04.
Sponsored by University of Kragujevac · Observational
Background. Definitive chemoradiotherapy represents the standard therapeutic approach for the management of locally advanced cervical cancer. Vitamin D plays an important role in the regulation of cellular growth and differentiation, immune system function, and the modulation of inflammatory processes. Hypovitaminosis D may be associated with the development of cervical cancer, whereas its impact on the effects of oncological treatment remains insufficiently elucidated. The aim of this study is to investigate the predictive significance of vitamin D in patients with locally advanced cervical cancer treated with definitive chemoradiotherapy.
Methods. This study is designed as a clinical, observational, prospective cohort study. Patients with locally advanced cervical cancer undergoing definitive chemoradiotherapy at the Clinic for Radiation Oncology, University Clinical Center Kragujevac, will be enrolled. Vitamin D concentrations will be measured before the initiation of treatment in both serum and cervical lavage samples. Baseline vitamin D levels will be analyzed in relation to treatment outcome and the occurrence of acute radiation toxicity. In addition, vitamin D concentrations will be evaluated in the context of clinical and morphological parameters, therapeutic response, and treatment-related toxicity.
Expected Results. This study will enable an assessment of the actual significance of pretreatment vitamin D concentrations in serum and cervical lavage as a potential novel biomarker in relation to chemoradiosensitivity and/or chemoradioresistance of cervical cancer, as well as the response of organs at risk, in patients with locally advanced disease.
Definitive concurrent chemoradiotherapy is the standard treatment for locally advanced cervical cancer. Although it achieves high response rates, some patients do not attain a complete therapeutic response, potentially because of chemoradioresistance. Radiotherapy also exerts immunomodulatory effects within the tumor microenvironment, which may be particularly relevant in cervical cancer because of its association with persistent human papillomavirus infection. Identifying biomarkers associated with treatment response and toxicity could therefore support more individualized treatment strategies.
Vitamin D regulates cellular proliferation and differentiation, immune responses, and inflammatory processes. Hypovitaminosis D and reduced vitamin D receptor expression have been associated with cervical cancer and other malignancies. However, the predictive value of pretreatment vitamin D status in patients undergoing modern definitive chemoradiotherapy remains insufficiently established.
Pretreatment vitamin D concentrations will be measured in serum and cervical lavage fluid. All participants will receive standard definitive treatment comprising external beam radiotherapy, brachytherapy, and concurrent weekly cisplatin-based chemotherapy. Acute treatment-related toxicity will be assessed throughout chemoradiotherapy, and the definitive therapeutic response will be evaluated by pelvic magnetic resonance imaging five months after treatment completion.
Pretreatment serum and cervical lavage vitamin D concentrations will be analyzed in relation to therapeutic response, acute treatment-related toxicity, and relevant clinical, morphological, treatment-related, and sociodemographic parameters. The study will also evaluate the correlation between systemic and local vitamin D concentrations and explore potential cut-off values for predicting complete therapeutic response and clinically significant acute toxicity. Participants with low pretreatment vitamin D concentrations will not receive supplementation as part of the study protocol.
801 studies on the registry are indexed under Vitamin D Deficiency; 60 are open to participants now.
This study's planned enrollment of 100 is below the median of 138 across 185 observational studies indexed under Vitamin D Deficiency.
Browse Vitamin D Deficiency studies →University of Kragujevac is the lead sponsor of 6 studies on the registry; 4 are open to participants now.
Counted across the registry records on this site, refreshed daily.
The study population will include adult individuals who self-identify as female, aged 18 to 80 years, with histopathologically confirmed locally advanced cervical cancer, FIGO 2018 stage IIB-IVA, who are planned for definitive concurrent chemoradiotherapy at the Clinic for Radiation Oncology, University Clinical Center Kragujevac. All participants must provide written informed consent and be eligible for standard treatment consisting of external beam radiotherapy, high-dose-rate brachytherapy, and weekly cisplatin-based chemotherapy.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
PD-1, PD-L1 and CTLA-4 are proteins that act as brakes on the immune system. Checkpoint inhibitors, such as pembrolizumab or nivolumab, block them so the immune system can attack a cancer.
PD-L1 can also be measured in a tumour sample. Some scores count stained tumour cells only (TPS); others also count certain immune cells (CPS). The study names the score and the minimum it uses.
ECOG performance status
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
PD-1, PD-L1 and checkpoint inhibitors
PD-1, PD-L1 and CTLA-4 are proteins that act as brakes on the immune system. Checkpoint inhibitors, such as pembrolizumab or nivolumab, block them so the immune system can attack a cancer.
PD-L1 can also be measured in a tumour sample. Some scores count stained tumour cells only (TPS); others also count certain immune cells (CPS). The study names the score and the minimum it uses.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients with histopathologically confirmed locally advanced cervical cancer, FIGO 2018 stage IIB-IVA, treated with definitive concurrent chemoradiotherapy. Pretreatment vitamin D concentrations will be measured in serum and cervical lavage fluid before treatment initiation, and patients will be followed for treatment response and acute radiation toxicity.
Diagnostic Test: Pretreatment Vitamin D Assessment in Serum and Cervical Lavage Fluid
Vitamin D concentrations will be measured before the initiation of definitive chemoradiotherapy in serum and cervical lavage fluid using chemiluminescence, as the standard institutional laboratory method. Baseline vitamin D levels will be analyzed in relation to treatment response, acute radiation toxicity, and selected clinical, morphological, treatment-related, and socio-demographic parameters.
Complete therapeutic response after definitive chemoradiotherapy
The proportion of patients achieving complete therapeutic response after definitive concurrent chemoradiotherapy. Treatment response will be assessed by pelvic magnetic resonance imaging and clinical examination, according to RECIST 1.1 criteria.
Time frame: Five months after the last radiotherapy fraction.
Clinically significant acute radiation toxicity
The proportion of patients developing clinically significant acute radiation toxicity during definitive chemoradiotherapy. Clinically significant toxicity will be defined as CTCAE v. 6 grade II or higher.
Time frame: First radiotherapy fraction until 90th day (acute toxicity).
Severity of acute radiation toxicity
The maximum grade of acute radiation toxicity observed during chemoradiotherapy, assessed according to CTCAE v.6 criteria.
Time frame: First radiotherapy fraction until 90th day.
Association between pretreatment serum vitamin D concentration and treatment response
Association between pretreatment serum vitamin D concentration and complete therapeutic response versus absence of complete therapeutic response after definitive chemoradiotherapy. Serum vitamin D concentration will be measured before treatment initiation using chemiluminescence as the standard institutional laboratory method.
Time frame: Baseline before treatment initiation and five months after the last radiotherapy fraction.
Association between pretreatment cervical lavage vitamin D concentration and treatment response
Association between pretreatment vitamin D concentration in cervical lavage fluid and complete therapeutic response versus absence of complete therapeutic response after definitive chemoradiotherapy. Vitamin D concentration in cervical lavage fluid will be measured before treatment initiation using chemiluminescence as the standard institutional laboratory method.
Time frame: Baseline before treatment initiation and five months after the last radiotherapy fraction.
Association between pretreatment vitamin D concentration and acute radiation toxicity
Association between pretreatment vitamin D concentrations in serum and cervical lavage fluid and the occurrence of clinically significant acute radiation toxicity, defined as CTCAE v.6 grade II or higher.
Time frame: Baseline before treatment initiation and 90th day.
Correlation Between Serum and Cervical Lavage Vitamin D Concentrations
Correlation between pretreatment vitamin D concentrations measured in serum and cervical lavage fluid.
Time frame: Baseline before initiation of chemoradiotherapy.
Optimal pretreatment vitamin D cut-off value for prediction of treatment response and toxicity
Receiver operating characteristic curve analysis will be used to determine the optimal pretreatment vitamin D cut-off value for prediction of complete therapeutic response and clinically significant acute radiation toxicity.
Time frame: Five months after the last radiotherapy fraction.
Plan to share: No — Individual participant data will not be shared because the study includes sensitive clinical, imaging, radiotherapy, toxicity, and biomarker data from patients with locally advanced cervical cancer. Data sharing is not planned in the current protocol and would require additional ethical approval, appropriate anonymization procedures, and a formal data sharing agreement.
Started Jan 2026 (actual). Primary completion is estimated for Jan 2028, 24 months after the start.
Of 61 non-industry observational studies under Vitamin D Deficiency, half reached primary completion within 19 months of starting (the median), counting those still running; a quarter within 9 and three quarters within 40. This study's planned 24 months is above that.
Counting every sponsor, half of 62 studies reached it within 19 months; a quarter within 9 and three quarters within 40.
How these figures are worked out, and which studies are left out of them.
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University of Kragujevac