Liquid biopsy: Urine as a sample type

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Early detection of cancer can greatly increase chances of survival and improve overall quality of life of a patient. Cancer biomarkers can be found in tissues as well as bodily fluids and can be used to detect the disease early as well as monitor disease progression (1). A high number of potentially informative cancer biomarkers have been found, including DNA, RNA, proteins and metabolites (1).

 

When tissue is an issue

A tissue biopsy is the traditional approach used to diagnose many cancers. However, obtaining a tissue sample has limitations (2,3).

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The procedure is invasive, painful, expensive, time intensive and requires the intervention of a clinician.

Further, due to intratumor heterogeneity, a tissue biopsy may not always reflect the entire tumor landscape. As a result, researchers are continuously exploring alternative methods to detect cancer types. The use of minimally invasive procedures such as liquid biopsies and detection of circulating tumor markers in body fluids, such as blood and urine is gaining interest (4) . Circulating molecules such as cell-free DNA, circulating tumor cells, circulating RNAs, proteins, peptides and exosomes can provide a global view of primary and metastatic tumors.

 

Advantages of liquid biopsies

Liquid biopsies have several advantages (4):

  • Allows (repeated) sampling
  • Provides a personalized snapshot of a disease at successive time points
  • Can better reflect the genetic profile of all tumor subclones
  • Associated with less morbidity and complications

 

Benefits of urine as a liquid biopsy

The most often used liquid biopsy is blood, which uses either serum or plasma as a sample type. However, blood as a liquid biopsy also has several limitations. Blood contains a relatively high and complex protein repertoire, that can interfere with biomarker measurements. Additionally, blood sampling is relatively invasive, and can pose a risk of infection for both the patient and the caregiver (5). Urine has been proposed as an alternative biofluid for detecting and monitoring treatment of urological and systemic cancers.

Urine sampling offers several benefits (5,6,7):

  • Easily accessible and available in larger quantities
  • Non-invasive
  • Applicable for home collection
  • Cost efficient
  • Not limited by the health status of a patient
  • Does not entail any risk of transmission of blood-borne pathogens

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Additionally, in terms of analysis, the isolation of DNA from urine is in theory easier than blood, due to the low protein content after filtration in the kidney (5,8).

 

Colli-Pee® as a urine collection device

To use urine for clinical applications, the preanalytical variation (collection, transport and storage) must be kept to a minimum. Collection through a standard urine cup can be awkward, messy and inconvenient for the user.

These can be overcome with Colli-Pee® , our is a urine collection device that allows for standardized and volumetric collection of urine and allows immediate mixing with preservative. Colli-Pee® variants allow easy collection of first-void urine. First-void urine has shown potential in screening and detection of Human Papillomavirus (HPV), the leading cause of cervical cancer. It has also shown potential in prostate cancer research.

References:
(1) PMID: 20716818 
(2) PMID: 25909508
(3) PMID: 21124216
(4) PMID: 28410618
(5) PMID: 21928247
(6) PMID: 29184671
(7) PMID: 25575913
(8) PMID: 15096565