Urine DNA Pilot Finds Cervical Cancer-Associated LOH Signals

Two sequential pilot studies from Sudan found that DNA collected from urine carried loss-of-heterozygosity, or LOH, signals associated with cervical cancer in small groups of women studied in 2010 and 2016. In the first pilot, four women had urinary allele-loss patterns while their concurrent Pap smears were entirely normal or non-atypical. In the second, LOH signals were identified in urine but not paired blood from 18 of 23 women with histologically confirmed cervical carcinoma. The researchers describe the findings as hypothesis-generating proof of concept, not a validated screening test.

The studies were designed to determine whether urinary DNA could provide a pre-cytological biomarker in a setting where cervical screening infrastructure was limited. The source reports that cervical cancer is the second most common malignancy among Sudanese women and that most cases present at an advanced stage because functional screening infrastructure is absent across much of the country. Papanicolaou smears also encounter cultural and logistical barriers, including reluctance among some women who have undergone female genital cutting to undergo speculum-based examination. The investigators therefore investigated self-collected urine as an alternative biological sample for molecular analysis.

For the 2010 pilot, researchers enrolled 20 women attending a routine gynecology clinic at Khartoum Teaching Hospital in Khartoum. Each participant also had a Pap smear assessed by an independent cytologist. DNA was extracted from urinary cell pellets using the guanidine chloride method. The investigators examined four microsatellite markers with PCR: D3S1300 at 3p14.2 in the FHIT region, D3S1260 at 3p22.2, D11S528 at 11q23.3 in the CADM1 region, and D11S35 at 11q22.1 in the ATM region. Amplified products were verified on 1.5% agarose gels and resolved by 8% polyacrylamide gel electrophoresis.

Sixteen of the 20 participants showed no allele loss at any of the four markers, consistent with their normal cytology. The remaining four showed urinary allele-loss patterns consistent with LOH at D3S1300 in one case and D11S35 in three cases. All four had entirely normal or non-atypical concurrent Pap smears. The observations show that the molecular signal was present in urine alongside a non-atypical cytology result, but the pilot did not establish whether those women had cervical neoplasia, whether abnormalities would appear later, or whether the urine findings had diagnostic value. The investigators specifically call for prospective validation with blood controls and longitudinal follow-up before clinical inference.

The second pilot enrolled 23 women with histologically confirmed cervical carcinoma at the Radiation and Isotopes Centre in Khartoum. For this group, paired blood DNA served as a germline reference. Somatic LOH was confirmed in 18 of 23 urine specimens, corresponding to 78.3% with a 95% confidence interval of 56.3% to 92.5%. Detection differed by marker: LOH occurred at D3S1300 in 52.2% of cases, D11S528 in 39.1%, D3S1260 in 34.8%, and D11S35 in 30.4%. LOH at two or more markers was present in 34.8% of the cancer cases. The corresponding allele loss was absent from all paired blood samples.

Together, the two studies provide initial Sudanese evidence that microsatellite LOH analysis is technically feasible using urinary DNA and can identify somatic-specific signals in cervical neoplastic epithelium. They do not establish a clinically ready screening assay. The samples were small, the second study included only women with already confirmed cervical carcinoma, and its detection estimate had a wide confidence interval. The four informative samples from the first pilot and 23 cancer cases from the second are insufficient for reliable estimation of sensitivity or specificity, including performance among women without cervical cancer.

LOH was not detected in 21.7% of the cervical cancers in the second pilot. The authors state that this may reflect tumor-suppressor-gene silencing through mechanisms other than LOH, principally promoter methylation, and propose evaluating a combined LOH-and-methylation panel in future work. That proposed panel was not tested in these studies. The present results establish a technical proof of concept rather than clinical benefit, predictive value or readiness for asymptomatic screening. Those questions remain unresolved and require larger prospective studies with appropriate controls and follow-up.

Subject of Research: Pilot evaluation of urinary microsatellite loss of heterozygosity in Sudanese women

Article Title: Urine-based microsatellite loss of heterozygosity as a pre-cytological biomarker for cervical cancer: two sequential pilot studies from Sudan

Article References: Latif, S. I. A., Bensumaidea, S. H., Mohamed, H. S., Elhoweris, M. H., Hummeida, M., & Ibrahim, M. E. (2026). Urine-based microsatellite loss of heterozygosity as a pre-cytological biomarker for cervical cancer: two sequential pilot studies from Sudan. BMC Cancer. https://doi.org/10.1186/s12885-026-16853-y

Image Credits: AI Generated

DOI: 10.1186/s12885-026-16853-y

Keywords: cervical cancer, urinary DNA, loss of heterozygosity, Pap smear, microsatellites, molecular biomarkers, Sudan, cervical screening, somatic mutations, proof of concept, Urine-based, microsatellite