The health and economic burdens posed by prostate cancer have driven improvements in how the disease is treated. Despite impressive medical advances, achieving early and accurate diagnoses still presents a challenge. A key limitation is associated with use of the prostate-specific antigen (PSA) as a diagnostic marker. This antigen is produced only by prostate tissue and has a significant functional role. Biomarkers such as these are used by medical professionals to help detect cancer early, and reduce the need for unnecessary biopsies. In the case of prostate cancer, it is done with this novel method by measuring changes in the glycan (complex carbohydrate) composition of the PSA. However, only a few of these markers have been approved for clinical use, while others have not been adequately validated. “The PSA is not a reliable biomarker, with high false-positive and false-negative results,” explains Andrea project coordinator Jan Tkac from the Institute of Chemistry at the Slovak Academy of Sciences, Slovakia. “False-positive results mean that men are sent to undergo biopsy, which is not needed since the biopsy will turn out to be negative. False-negative results mean that a prostate cancer is not detected, and could become more aggressive.”
Accurate clinical diagnoses
The main aim of the Andrea project, which was supported by the European Research Council, was to design a more robust clinical kit for the accurate and early diagnosis of prostate cancer. A magnetic bead-based assay using lectins (a family of proteins) was developed and evaluated using 140 biobank samples. “We wanted to evaluate our test as a means of diagnosing early stage prostate cancer, and also as a second opinion device to help medical professionals decide whether to conduct a biopsy,” says Tkac. “We wanted the test to be able to discriminate early stage prostate cancer from patients with advanced disease.” Serum samples from men who underwent recent prostate biopsies were used. A comparison was then made between two equal groups of men with either confirmed prostate cancer or a benign, non-cancer condition. This enabled the project team to assess their innovation against current practices.
Closer to market
The results confirmed that the kit was able to diagnose prostate cancer at an early stage, be effectively applied as a second opinion ahead of a biopsy and discriminate between early stage and advanced cancer. A key benefit for patients, and indeed the medical sector as a whole, could be a significant reduction in the number of unnecessary biopsies. “Biopsies are painful and costly,” adds Tkac. “Only a limited number of biopsies can be performed, since the prostate is quite a small organ.” Following the successful evaluation of the assay kit, the project consortium has filed for patents through the European Patent Office (EPO). Clinical validation on a larger cohort from several countries is now planned, in order to gather more data. Here, the project consortium plans to focus heavily on analysing samples from the so-called ‘grey zone’. “This describes a situation where it is very difficult for urologists to say whether a patient has to undergo a biopsy or not,” explains Tkac. After successful clinical validation, the project consortium will apply for the CE mark in order to attract interest from pharmaceutical and diagnostic companies and take the product closer to market. Commercialisation will eventually be carried out through the consortium’s newly incorporated start-up, called Glycanostics.
Andrea, medical, prostate, cancer, PSA, glycan, biopsy, disease, biobank