ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 SPINK1- subset (30 cases/28.57%) presented no significant cor- relation between low/high TFF3 expression, clinico-pathological parameters, and biochemical recurrence. ERG+/SPINK1+ subset included one case, with TFF3 over-expression; statistical analysis wasn’t applicable in this situation. Conclusion: Currently, the classification of prostate cancer in distinct molecular subclasses is still a “hot” debatable issue with exploring potential in modern pathology and oncology. The immuno-expression profile of TFF3 differs in subsets of sporadic prostatic adenocarcinoma outlined by ERG/SPINK1 status, its over-expression indicating a more aggressive biological and clini- cal behaviour. Further studies on bigger populations are required for a better understanding of the overlapping interactions between SPINK1, ERG and TFF3 in the progression and molecular stratifi- cation of this malignancy. PS-26-027 Biomarkers implied in prostate cancer progression by flow cytometry analysis E. Matei*, A.C. Ionescu, M. Aschie, M. Enciu, M. Deacu, A. Mitroi, S.T. Topliceanu, N. Dobrin, C. Stefanov, G.C. Cozaru *CEDMOG “Ovidius” University of Constanta, Romania Background & objectives: Researchers need a greater understanding of prostate intratumoral heterogeneity and the cellular architecture of normal and diseased tissues to develop better treatments and more accurately predict disease progression. Methods: The study presents flow cytometry determinations on prostate biopsies recovered from patients with adenocarcinomas (PCa, n=25), benign prostatic hyperplasia (BPH, n=25) reported to controls (C, n=25) to evaluate the DNA content, cell apoptosis, and CD biomarkers (CD34 Alexa Fluor 488/ CD61-PE stain for mesenchymal, endothelial cell proliferation and CD42b-PE stain for platelets aggregation to tumoral cells and endothelium). Results: The results showed that 68% of BPH cases and 88% of patients with PCa presented aneuploidy. Relationships between the development of PCa, BPH with adhesion, migration, and cell prolifera- tion were observed by Pearson correlations between G0/G1 phase of cell cycle and CD34+CD61+ glycoproteins (r=-0.514; P<0.01), and CD42b+ cell population (r=-0.475; P<0.05), between G2/M phase of cell cycle and CD34+CD61+ glycoproteins (r=0.513; P<0.01), and CD42b+ cell population (r=0.446; P<0.05), between S phase and CD61+ cell population (r=-0.430; P<0.05). Conclusion: Combining the benefits of advanced high throughput flow cytometry and live-cell analysis offers the potential to gain additional insights into the mechanisms of cancer progression. It is concluded that DNA flow cytometry has much to tell us about the natural history and biological behaviour of prostate cancer and along with CD biomarkers provides additional information about the prognosis of the disease. Funding: This work was supported by the PROMETEU project, in the framework of the Ovidius University of Constanta biomedical grant competition, contract no. 6 / 20.10.2021. PS-26-028 Correlation of GATA3, CK5/6 and p16 expression and overall survival in muscle-invasive bladder cancer R. Terlevic*, M. Ulamec, J. Murgić, G. Štimac, B. Krušlin *Pula General Hospital, Croatia Background & objectives: Muscle-invasive bladder cancer therapy choice could be influenced by the tumour molecular subtype. Currently well-defined subtypes are RNA based. Surrogate molecular subtypes based on immunohistochemistry are needed to make subtyping useful in routine work and facilitate future research. Methods: A retrospective single centre series of 85 cases with localized disease was identified, and routine immunohistochem- istry for GATA3, CK5/6 and p16 was performed on whole tissue blocks containing muscle-invasive disease. Surrogate molecular subtypes were defined. Patient information regarding treatment and survival was obtained from medical archives. Results: The mean population age was 70 years (SD=8.7), and 73% were males. Conservative treatment (TURwith radiotherapy) was used in 45% of cases, while 47% underwent cystectomy with adjuvant chemotherapy. Only 7% underwent neoadjuvant chemotherapy or primary chemoradiotherapy. GATA3 and CK5/6 expression segregated cases into broad luminal and basal subtypes respectively, while p16 expression was used to subclassify luminal cases into luminal papillary and luminal unstable types. When sub- typed this way, no difference in survival was observed overall and within therapy groups. GATA3 expression was strongly associated with better sur- vival across all treatment groups, while CK5/6 was linked to worse survival. No effect of p16 on survival was observed. Conclusion: No effect of p16 expression was observed on clinical outcome. When used together with GATA3 and CK5/6 in a combined immunohistochemical molecular subtype no difference in survival was observed. In our study GATA3 and CK5/6 expression was found to be an indicator of respectively improved and worse survival both overall and within conservatively treated and cystectomised patients. PS-26-029 Dynamic sentinel node biopsies in penile cancer – the Edin- burgh experience R. Grigorescu*, M. O’Donnell *NHS Lothian, United Kingdom Background & objectives: The presence and extent of loco-regional lymph node metastasis is an important prognostic factor in penile can- cer survival and therefore dynamic sentinel node biopsies of inguinal lymph nodes play an important role. Methods: A retrospective review of all DSNB for penile cancer reported in our department over a 5-year period (2015-2019) was performed. This looked at initial diagnosis, reported macroscopic and histological features, use of immunohistochemistry and follow up including additional pathology. Locally all nodes are individually identified, serially sliced at 2 mm intervals and further ancillary tests done by request only. Results: 67 cases were identified, with a total of 168 lymph nodes. Immunohistochemistry was performed in 11 cases. 14 nodes (7%) over 11 cases had metastatic tumour deposits. Two of these were micrometastasis (<2 mm) and both these patients had negative sub- sequent lymph node dissections. In patients with non-micrometa- static disease, there was an association of the size of the sentinel node deposit and the likelihood of further positive nodes in the node dissection. In four of the cases with negative sentinel nodes initially, ipsilateral metastatic nodal disease was identified subsequently. These cases had further additional levels and cytokeratin immunohistochemis- try performed but were true negatives. Conclusion: Although our sample size is small, it raises the pos- sibility that micrometatastic disease within DSNB may not be associated with further positive nodes in the node clearance and may benefit from further larger studies to see if clearance could be avoided for this subgroup of patients. We did not identify any false positive or false negative cases in our review. S175