The Uropathology Symposium of the EAU Section of Uropathology (ESUP) delivered the latest updates on biomarkers and molecular tests in bladder urothelial cancer, with included presentations on molecular differences between primary bladder tumours and metastasis and differences in PDL- 1 expression, as well as a case presentation for a proposal of a new grading in non-muscle invasive bladder cancer (NMIBC), followed by a lecture on artificial intelligence in uropathology.
Taking place on day one of EMUC23 in Marseille, the symposium was co-chaired by Prof. Maurizio Colecchia (IT), Prof. Kerstin Junker (DE) and Dr. Gladell Paner (US).
Dr. Markus Eckstein (DE) presented his lecture ‘Molecular differences between primary bladder tumours and metastasis and differences in PDL – 1 expression’. He began by explaining the metastatic evolution from stem(s) to branches. “Tumour properties driving clonal evolution include genetic alterations, cell cycle alterations, DNA-repair alterations, cell mortality and EMT/MET.”
He stated that metabolic effects include the environment such as oxygen, nutrients and hormones. Immunological selection pressure includes immune invasion and immune suppression. Niche properties include nutrient/oxygen supply, immune surveillance (liver, brain and bone), and stroma conditions.
With this highly complex interaction between many cell populations and environmental factors, Prof. Eckstein concluded with the question, “Can we go on testing biomarkers in primary tumours for precision oncology?”
Middle-grade NMIBC?
A case study was shared by pathologist Prof. Colecchia (IT) during his lecture ‘Proposal of a new grading in non-muscle invasive bladder cancer’. He took a deep dive into explaining how the grading recommendations for NMIBC could be improved, as well as the reproducibility of the grading system.
Prof. Colecchia sited several studies that tried to correlate outcomes between heterogeneous grades. “There were different thresholds for the fraction of high-grade cells. If it is a <10% of a high-grade tumour cell, there was no change in clinical outcomes of low-grade carcinoma. Distinction between low-risk and intermediate-to-high-risk carcinoma can provide the basis for adjuvant intravesical instillation and regimen of BCG (Bacillus Calmette-Guerin) [with its significant side effects].”
Prof. Colecchia reported that in 2022, the WHO proposed criteria for reporting papillary tumours as high-grade as long as the high-grade component represents >5% of the tumour. Moreover, tumours with <5% high-grade component should be reported as ‘low-grade with <5% high-grade component’.
To watch the full presentation, visit the EMUC23 Resource Centre.
