HER3 (ERBB3) amplification in liposarcoma - a putative new therapeutic target?

BACKGROUND: Liposarcomas are among the most common mesenchymal malignancies. However, the therapeutic options are still very limited and so far, targeted therapies had not yet been established. Immunotherapy, which has been a breakthrough in other oncological entities, seems to have no efficacy in liposarcoma. Complicating matters further, classification remains difficult due to the diversity of morphologies and nonspecific or absent markers in immunohistochemistry, leaving molecular pathology using FISH or sequencing as best options. Many liposarcomas harbor MDM2 gene amplifications. In close relation to the gene locus of MDM2, HER3 (ERBB3) gene is present and co-amplification could occur. Since the group of HER/EGFR receptor tyrosine kinases and its inhibitors/antibodies play a role in a broad spectrum of oncological diseases and treatments, and some HER3 inhibitors/antibodies are already under clinical investigation, we hypothesized that in case of HER3 co-amplifications a tumor might bear a further potential therapeutic target. METHODS: We performed FISH analysis (MDM2, DDIT3, HER3) in 56 archived cases and subsequently performed reclassification to confirm the diagnosis of liposarcoma. RESULTS: Next to 16 out of 56 cases needed to be re-classified, in 20 out of 54 cases, a cluster-amplification of HER3 could be detected, significantly correlating with MDM2 amplification. Our study shows that the entity of liposarcomas show specific molecular characteristics leading to reclassify archived cases by modern, established methodologies. Additionally, in 57.1% of these cases, HER3 was cluster-amplified profusely, presenting a putative therapeutic target for targeted therapy. CONCLUSION: Our study serves as the initial basis for further investigation of the HER3 gene as a putative therapeutic target in liposarcoma.

Alternative mRNA Splicing Controls the Functions of the Histone H3K27 Demethylase UTX/KDM6A.

The UTX/KDM6A histone H3K27 demethylase plays an important role in development and is frequently mutated in cancers such as urothelial cancer. Despite many studies on UTX proteins, variations in mRNA splicing have been overlooked. Using Nanopore sequencing, we present a comprehensive analysis of UTX/KDM6A splicing events in human cell lines and in tissue samples from bladder cancer cases and normal epithelia. We found that the central region of UTX mRNAs encoded by exons 12 to 17 undergoes extensive alternative splicing. Up to half of all stable mRNAs (8-48% in bladder tissues and 18-58% in cell lines) are represented by the UTX canonical isoform lacking exon 14 encoding a nuclear localization sequence, and hence exon 14-containing UTX isoforms exclusively localize to the nucleus, unlike the cytonuclear localization of the canonical isoform. Chromatin association was also higher for exon-14-containing isoforms compared to the canonical UTX. Using quantitative mass spectrometry, we found that all UTX isoforms integrated into the MLL3 and MLL4, PR-DUB and MiDAC complexes. Interestingly, one of the novel UTX isoforms, which lacks exons 14 and 16, fails to interact with PR-DUB and MiDAC complex members. In conclusion, UTX mRNAs undergo extensive alternative splicing, which controls the subcellular localization of UTX and its interactions with other chromatin regulatory complexes.

[New WHO classification 2022: urinary bladder cancer]. / Neue WHO-Klassifikation 2022: Harnblasenkarzinom.

The new World Health Organization (WHO) classification of urogenital tumors is still primarily based on anatomic location, but is also a hierarchical taxonomic classification without separate chapters for tumors of the upper urinary tract and the urethra. It clarifies aspects regarding grading and noninvasive entities. It consolidates the use of the Paris system for urinary cytology as well as various subtypes/special types of neoplasms, and incorporates general concepts of the 5th edition of the WHO blue book. In addition to mesenchymal tumors, well-differentiated neuroendocrine tumors and neuroendocrine carcinomas are addressed in separate chapters. Papillary non-invasive low- and high-grade carcinomas and carcinoma in situ remain, while dysplasia and urothelial proliferation of unknown malignant potential (UPUMP) are no longer treated as separate entities. Former variants of urothelial carcinoma are now called subtypes and aberrant differentiation and special types are more precisely defined.

Identification and Validation of Potentially Clinically Relevant CpG Regions within the Class 2 Tumor Suppressor Gene SFRP1 in Pancreatic Cancer.

In pancreatic cancer treatment, tumor stage-dependent chemotherapies are used to prolong overall survival. By measuring DNA promoter hypermethylation in the plasma of patients with stage IV pancreatic cancer, it was recently shown that promoter DNA methylation of the tumor suppressor gene SFRP1 has a high value for predicting failure of drug treatment with gemcitabine. In this study, we therefore aimed to identify as precisely as possible the region in the SFRP1 promoter that is frequently hypermethylated in pancreatic cancer tissue. First, we used the TCGA data set to define CpG-rich regions flanking the SFRP1 transcription start site that were significantly more methylated in pancreatic cancer compared to normal pancreatic acinar tissue. A core CpG island was identified that exhibited abundant tumor DNA methylation and anti-correlation of SFRP1 mRNA expression. To validate our in silico results, we performed bisulfide conversion followed by DNA pyrosequencing of 28 matched formalin-fixed, paraffin-embedded (FFPE) pancreatic cancer cases and six pancreatic cancer cell lines. A defined block of seven CpG sites within the core CpG island was identified, which confirmed our in silico results by showing significantly higher SFRP1 methylation in pancreatic cancer specimens than in normal pancreatic tissue. By selecting this core CpG island, we were able to determine a median overall survival benefit for the low SFRP1 methylation group compared to the high SFRP1 methylation group (702 versus 517 days, p = 0.01) in the TCGA pancreatic cancer cohort. We propose a compact pyrosequencing assay that can be used in the future to further investigate the prognostic value of SFRP1 promoter hypermethylation in predicting pancreatic cancer chemoresistance. Therefore, instead of DNA analysis from blood (liquid biopsy), DNA easily extractable from cancer tissue blocks (FFPE material) could be used.

Optical coherence tomography and convolutional neural networks can differentiate colorectal liver metastases from liver parenchyma ex vivo.

PURPOSE: Optical coherence tomography (OCT) is an imaging technology based on low-coherence interferometry, which provides non-invasive, high-resolution cross-sectional images of biological tissues. A potential clinical application is the intraoperative examination of resection margins, as a real-time adjunct to histological examination. In this ex vivo study, we investigated the ability of OCT to differentiate colorectal liver metastases (CRLM) from healthy liver parenchyma, when combined with convolutional neural networks (CNN). METHODS: Between June and August 2020, consecutive adult patients undergoing elective liver resections for CRLM were included in this study. Fresh resection specimens were scanned ex vivo, before fixation in formalin, using a table-top OCT device at 1310 nm wavelength. Scanned areas were marked and histologically examined. A pre-trained CNN (Xception) was used to match OCT scans to their corresponding histological diagnoses. To validate the results, a stratified k-fold cross-validation (CV) was carried out. RESULTS: A total of 26 scans (containing approx. 26,500 images in total) were obtained from 15 patients. Of these, 13 were of normal liver parenchyma and 13 of CRLM. The CNN distinguished CRLM from healthy liver parenchyma with an F1-score of 0.93 (0.03), and a sensitivity and specificity of 0.94 (0.04) and 0.93 (0.04), respectively. CONCLUSION: Optical coherence tomography combined with CNN can distinguish between healthy liver and CRLM with great accuracy ex vivo. Further studies are needed to improve upon these results and develop in vivo diagnostic technologies, such as intraoperative scanning of resection margins.

Ultrasound-directed enzyme-prodrug therapy (UDEPT) using self-immolative doxorubicin derivatives.

Background: Enzyme-activatable prodrugs are extensively employed in oncology and beyond. Because enzyme concentrations and their (sub)cellular compartmentalization are highly heterogeneous in different tumor types and patients, we propose ultrasound-directed enzyme-prodrug therapy (UDEPT) as a means to increase enzyme access and availability for prodrug activation locally. Methods: We synthesized ß-glucuronidase-sensitive self-immolative doxorubicin prodrugs with different spacer lengths between the active drug moiety and the capping group. We evaluated drug conversion, uptake and cytotoxicity in the presence and absence of the activating enzyme ß-glucuronidase. To trigger the cell release of ß-glucuronidase, we used high-intensity focused ultrasound to aid in the conversion of the prodrugs into their active counterparts. Results: More efficient enzymatic activation was observed for self-immolative prodrugs with more than one aromatic unit in the spacer. In the absence of ß-glucuronidase, the prodrugs showed significantly reduced cellular uptake and cytotoxicity compared to the parent drug. High-intensity focused ultrasound-induced mechanical destruction of cancer cells resulted in release of intact ß-glucuronidase, which activated the prodrugs, restored their cytotoxicity and induced immunogenic cell death. Conclusion: These findings shed new light on prodrug design and activation, and they contribute to novel UDEPT-based mechanochemical combination therapies for the treatment of cancer.

Automated PD-L1 Scoring Using Artificial Intelligence in Head and Neck Squamous Cell Carcinoma.

Immune checkpoint inhibitors (ICI) represent a new therapeutic approach in recurrent and metastatic head and neck squamous cell carcinoma (HNSCC). The patient selection for the PD-1/PD-L1 inhibitor therapy is based on the degree of PD-L1 expression in immunohistochemistry reflected by manually determined PD-L1 scores. However, manual scoring shows variability between different investigators and is influenced by cognitive and visual traps and could therefore negatively influence treatment decisions. Automated PD-L1 scoring could facilitate reliable and reproducible results. Our novel approach uses three neural networks sequentially applied for fully automated PD-L1 scoring of all three established PD-L1 scores: tumor proportion score (TPS), combined positive score (CPS) and tumor-infiltrating immune cell score (ICS). Our approach was validated using WSIs of HNSCC cases and compared with manual PD-L1 scoring by human investigators. The inter-rater correlation (ICC) between human and machine was very similar to the human-human correlation. The ICC was slightly higher between human-machine compared to human-human for the CPS and ICS, but a slightly lower for the TPS. Our study provides deeper insights into automated PD-L1 scoring by neural networks and its limitations. This may serve as a basis to improve ICI patient selection in the future.

SARS-CoV-2 RNA screening in routine pathology specimens.

Virus detection methods are important to cope with the SARS-CoV-2 pandemics. Apart from the lung, SARS-CoV-2 was detected in multiple organs in severe cases. Less is known on organ tropism in patients developing mild or no symptoms, and some of such patients might be missed in symptom-indicated swab testing. Here, we tested and validated several approaches and selected the most reliable RT-PCR protocol for the detection of SARS-CoV-2 RNA in patients' routine diagnostic formalin-fixed and paraffin-embedded (FFPE) specimens available in pathology, to assess (i) organ tropism in samples from COVID-19-positive patients, (ii) unrecognized cases in selected tissues from negative or not-tested patients during a pandemic peak, and (iii) retrospectively, pre-pandemic lung samples. We identified SARS-CoV-2 RNA in seven samples from confirmed COVID-19 patients, in two gastric biopsies, one small bowel and one colon resection, one lung biopsy, one pleural resection and one pleural effusion specimen, while all other specimens were negative. In the pandemic peak cohort, we identified one previously unrecognized COVID-19 case in tonsillectomy samples. All pre-pandemic lung samples were negative. In conclusion, SARS-CoV-2 RNA detection in FFPE pathology specimens can potentially improve surveillance of COVID-19, allow retrospective studies, and advance our understanding of SARS-CoV-2 organ tropism and effects.

The Impact of Fluorescence in situ Hybridization on the Staging of Upper Tract Urothelial Carcinoma.

OBJECTIVES: The aim of the study was to evaluate the impact of fluorescence in situ hybridization (FISH) diagnostics on the T stage in final histology specimen of patients undergoing radical nephroureterectomy (RNU) due to upper tract urothelial carcinoma (UTUC) at a large tertiary care center. METHODS: We retrospectively analyzed patients who underwent RNU at our center between 2008 and 2020. Inclusion criteria were RNU due to UTUC. Urine cytologies were used for FISH analysis to detect chromosomal abnormalities. Pre-FISH group was defined as patients without access to routine preoperative urinary FISH testing (2008-2014), and FISH group was defined as patients with access to routine FISH testing. Primary outcome was T stage in final histology. Statistical analysis was performed by χ2 test and Mann-Whitney U test. RESULTS: Out of 212 patients who underwent RNU at our center between 2008 and 2020, 155 patients were included into the final analysis. The median age was 71 (range 33-90) years, and 108 (69.7%) patients were male and 47 (30.3%) female. Age and gender were not differently distributed in both groups (age: p = 0.925; gender: p = 0.682). Organ-confined disease was found in 37/72 patients in the pre-FISH cohort and in 48/83 patients in the FISH cohort (p = 0.422). Within organ-confined disease, 18/37 patients revealed a T stage smaller than T1 in the pre-FISH cohort and 35/48 patients in the FISH cohort (p = 0.022). CONCLUSIONS: Preoperative FISH diagnostics add important information to preoperative diagnostic workup of patients with UTUC. Within organ-confined disease, a significant shift toward T stages lower than T1 is observed. Further research is required to determine the impact of this shift on survival in UTUC.

Impact of Angiogenesis- and Hypoxia-Associated Polymorphisms on Tumor Recurrence in Patients with Hepatocellular Carcinoma Undergoing Surgical Resection.

Tumor angiogenesis plays a pivotal role in hepatocellular carcinoma (HCC) biology. Identifying molecular prognostic markers is critical to further improve treatment selection in these patients. The present study analyzed a subset of 10 germline polymorphisms involved in tumor angiogenesis pathways and their impact on prognosis in HCC patients undergoing partial hepatectomy in a curative intent. Formalin-fixed paraffin-embedded (FFPE) tissues were obtained from 127 HCC patients at a German primary care hospital. Genomic DNA was extracted, and genotyping was carried out using polymerase chain reaction (PCR)-restriction fragment length polymorphism-based protocols. Polymorphisms in interleukin-8 (IL-8) (rs4073; p = 0.047, log-rank test) and vascular endothelial growth factor (VEGF C + 936T) (rs3025039; p = 0.045, log-rank test) were significantly associated with disease-free survival (DFS). After adjusting for covariates in the multivariable model, IL-8 T-251A (rs4073) (adjusted p = 0.010) and a combination of "high-expression" variants of rs4073 and rs3025039 (adjusted p = 0.034) remained significantly associated with DFS. High-expression variants of IL-8 T-251A may serve as an independent molecular marker of prognosis in patients undergoing surgical resection for HCC. Assessment of the patients' individual genetic risks may help to identify patient subgroups at high risk for recurrence following curative-intent surgery.

An unusual case of aortic metastasis from lung cancer.

In patients with cardiovascular events, such as myocardial infarction or aortic dissection without known risk factors for cardiovascular disease, neoplastic disease should be considered as a differential diagnosis. In this report, we present a case of a 51-year old man with previously undiagnosed non-small lung cancer leading to fatal cardiovascular complications due to hemovascular spread, diagnosed post-mortem. This case illustrates the value of autopsy in unexpected deaths.

Development of a Rapid Analysis Method for Bone Resection Margins for Oral Squamous Cell Carcinoma by Immunoblotting.

The purpose of this proof-of-principle study was to develop a rapid and approachable method to analyse bone resection margins in patients with oral squamous cell carcinoma (OSCC) in an intraoperative setting, similar to assessing frozen sections of soft tissue. Bone excision and risk of remaining tumour cells could be minimised, thus improving reconstruction measures and facilitating convalescence. Frozen, sawed wafers of porcine bone artificially combined with porcine skin (simulating OSCC properties) were used to develop and evaluate a new molecular method: protein transfer from non-decalcified, sawed wafers onto a membrane stained by immunofluorescence (Tissue-ProtTrans). Tissue-ProtTrans was based on the detection of keratin 5/6 as a marker of tumour cells. The results were compared to standard immunohistochemistry (IHC) and H&E results of the same wafers after decalcification. Tissue-ProtTrans resulted in a total assay time of 3.5 h using the Trans-Blot® Turbo™ Transfer System (Bio-Rad) for protein transfer. Amersham Protran® Premium Nitrocellulose Membranes 0.2 µm (GE Healthcare) were stained with a primary antibody to keratin 5/6 (Dako Agilent) and a secondary antibody labelled with IRDye® 800CW (LI-COR). Visualisation was performed with an infrared laser scanner (Odyssey). Upon comparison, five independent experiments on porcine specimens processed with the Tissue-ProtTrans showed similar results to standard IHC and H&E analysis. In comparison to standard IHC results (requiring several days due to decalcification) Tissue-ProtTrans provided similar results, but was much faster (3.5 h). This highly promising method has good potential for further time reduction and will be suitable for intraoperative assessment.

Therapy-relevant aberrant expression of MRP3 and BCRP mRNA in TCC-/SCC-bladder cancer tissue of untreated patients.

Multidrug resistance (MDR) is a critical factor, which results in suboptimal outcomes in cancer chemotherapy. One principal mechanism of MDR is the increased expression of ATP-binding cassette (ABC) transporters. Of these, multidrug resistance-associated protein 3 (MRP3) and breast cancer resistance protein (BCRP) confer MDR when overexpressed in cancer cell lines. We measured the mRNA expression of MRP3 and BCRP in primary untreated bladder cancer specimens using reverse transcription-quantitative PCR (RT-qPCR) in comparison to normal bladder tissue. The MRP3 and BCRP expression in the two major histotypes of bladder cancer; transitional cell carcinoma (TCC; urothelial type of bladder cancer) and squamous cell carcinoma (SCC; 'Schistosoma-induced' bladder cancer) were compared. Furthermore, the association between MRP3 and BCRP expression and tumor grade and stage were investigated. MRP3 mRNA expression in bladder cancer specimens was increased ~13-fold on average compared to normal bladder tissue (n=36, P<0.0001). BCRP mRNA expression was decreased in bladder cancer specimens to ~1/5 on average, compared to normal bladder tissue (n=38, P<0.0001). TCC showed significantly increased MRP3 mRNA expression compared to SCC of the bladder (P<0.0001). BCRP mRNA expression was similar in TCC and SCC of the bladder (P=0.1072). The increased MRP3 mRNA expression was not related to bladder tumor grade (P=0.3465) but was, however, significantly higher in superficial than in invasive bladder tumors (P=0.0173). The decreased expression of BCRP was not related to bladder tumor grade (P=0.1808) or stage (P=0.8016). The current data show that bladder cancer is associated with perturbed expression of MRP3 and BCRP. Representing drug resistance factors, determining the expression of these transporters in native tumors may be predictive of the outcome of chemotherapy based-treatment of bladder cancer.

Sextant-Specific Analysis of Detection and Tumor Volume by HistoScanning™.

INTRODUCTION: Published results of HistoScanning™ (HS) for prostate cancer (PCa) diagnostics are inconsistent and their value remains unclear. We prospectively analyzed the detection rate and tumor volume concordance in PCa patients. MATERIAL AND METHODS: Two hundred and eighty-two patients with biopsy-proven PCa scheduled for radical prostatectomy (RP) were included. All patients underwent ultrasonographical examination by HS prior to surgery. HS was evaluated compared to RP specimen as to (1) the prediction of overall tumor volume and (2) accuracy of HS in detection of PCa lesions larger than 0.2/0.5 ml, separated for each sextant. For each sextant, receiver operating characteristic (ROC)-analysis and area under the curve were determined. Sensitivity and specificity were calculated and visualized in ROC-curves. RESULTS: HS tends to underestimate volume of cancerous lesions, particularly larger lesions >8 ml. Using a 0.2 ml detection threshold, specificity and sensitivity of HS were between 29-68% and 46-78%. For a 0.5 ml detection threshold, sextant-specific specificity increased to 59-92% and sensitivity decreased to 16-54%. Stratification according to pre-operational PSA values did not improve performance characteristics of HS. CONCLUSIONS: Our results do not support a significant contribution of HS to PCa diagnostics.

Risk and timing of biochemical recurrence in pT3aN0/Nx prostate cancer with positive surgical margin - A multicenter study.

BACKGROUND AND PURPOSE: Positive surgical margins (PSM) after radical prostatectomy have been shown to be associated with impaired outcome. In pT3pN0 patients with PSM either immediate radiotherapy or clinical and biological monitoring followed by salvage radiotherapy is recommended by the latest guidelines of the European Association of Urology. MATERIALS AND METHODS: A retrospective, multicenter study of eight urological centers was conducted on 536 prostatectomy patients with pT3aN0/NxR1 tumors and no neoadjuvant/adjuvant therapy. A pathological re-review of all prostate specimens was performed. Association of clinical and pathological features with biochemical recurrence (BCR) was analyzed using univariate and multivariate analysis. RESULTS: With 48months median follow-up, BCR occurred in 39.7%. Preoperative PSA value, performance of pelvic lymph node dissection and Gleason score were significantly associated with BCR. In multivariate analysis, Gleason score was the only independent prognostic factor (p<0.001) for BCR. Five-year BCR-free survival rates were 74%, 70%, 38%, and 51% with Gleason score 6, 3+4=7a, 4+3=7b, and 8-10, respectively. CONCLUSIONS: In pT3aN0/NxR1 patients with no adjuvant/neoadjuvant treatment, Gleason Score permits independent prediction of the risk for BCR. These findings could help to estimate and discuss the individual risk for BCR with our patients on an individual basis.

Optical tomography of MMP activity allows a sensitive noninvasive characterization of the invasiveness and angiogenesis of SCC xenografts.

For improved tumor staging and therapy control, imaging biomarkers are of great interest allowing a noninvasive characterization of invasiveness. In squamous epithelial skin and cervix lesions, transition to invasive stages is associated with enhanced matrix metalloproteinase (MMP) activity, increased angiogenesis, and worsened prognosis. Thus, we investigated MMP activity as imaging biomarker of invasiveness and the potential of optical tomography in characterizing the angiogenic and invasive behavior of skin squamous cell carcinoma (SCC) xenografts. MMP activity was measured in vivo in HaCaT-ras A-5RT3 tumors at different angiogenic and invasive stages (onset of angiogenesis, intermediate and highly angiogenic, invasive stage) and after 1 week of sunitinib treatment by fluorescence molecular tomography-microcomputed tomography imaging using an activatable probe. Treatment response was additionally assessed morphologically by optical coherence tomography (OCT). In vivo MMP activity significantly differed between the groups, revealing highest levels in the highly angiogenic, invasive tumors that were confirmed by immunohistochemistry. At the onset of angiogenesis with lowest MMP activity, fibroblasts were detected in the MMP-positive areas, whereas macrophages were absent. Accumulation of both cell types occurred in both invasive groups, again to a significantly higher degree at the most invasive and angiogenic stage. Sunitinib treatment significantly reduced the MMP activity and accumulation of fibroblasts and macrophages and blocked tumor invasion that was additionally visualized by OCT. Human cervical SCCs also showed high MMP activity and a similar stromal composition as the HaCaT xenografts, whereas normal tissue was negative. This study strongly suggests MMP activity as imaging biomarker and demonstrates the high sensitivity of optical tomography in determining tumor invasiveness that can morphologically be supported by OCT.

Radical cystectomy in the elderly patient: a contemporary comparison of perioperative complications in a single institution series.

PURPOSE: To report on our recent experience with peri- and postoperative morbidity of radical cystectomy in patients 75 years and older compared to younger patients. PATIENTS AND METHODS: Medical records of 326 consecutive patients undergoing radical cystectomy from May 2004 through April 2008 were reviewed. RESULTS: Eighty-five of 326 patients (26%) were > or =75 years (75-95) old. ASA score was equal 3 or greater in 51% of patients > or =75 years and 32% of patients <75 years. Ileal conduit was performed in 83% of patients > or =75, 16% received an ileal neobladder compared to 46 and 51%, respectively, in patients <75. A total of 33 patients (39%) in the older patient group received blood transfusions intraoperatively compared to 76 patients (32%) in the younger age group. In 6 patients > or =75 years (7.1%) and 17 patients <75 (7.1%) open surgical revision was necessary, perioperative complication rate was 22 and 21%, respectively. The most common complications were wound dehiscence (5.9 vs. 7.5%), infections (4.7 vs. 4.6%), and pulmonary embolism (3.5 vs. 2.1%). Perioperative mortality was 1.2% (1 patient) in the elderly versus 0.4% (1 patient) in the younger age group. CONCLUSION: Our data show that radical cystectomy can be offered to the elderly patient with acceptable morbidity. Because of higher comorbidity rate in the elderly, therapeutic decision for radical cystectomy in elderly patients should be made carefully and individually. Nevertheless our results demonstrate that age itself is not a main criterion which has to be considered strongly in decision making for radical cystectomy.

Photodynamic diagnosis using 5-aminolevulinic acid for the detection of positive surgical margins during radical prostatectomy in patients with carcinoma of the prostate: a multicentre, prospective, phase 2 trial of a diagnostic procedure.

BACKGROUND: Surgical margin status after radical prostatectomy (RP) is a significant risk factor for tumour recurrence. It is an intriguing concept to find a fluorescence marker for photodynamic diagnosis (PDD) to make tumour margins visible during surgery. OBJECTIVE: To investigate the feasibility of identification of positive surgical margins (PSM) during open retropubic or endoscopic extraperitoneal RP by 5-aminolevulinic acid (5-ALA)-induced protoporphyrin IX (PpIX) to enhance surgical radicality. DESIGN, SETTING, AND PARTICIPANTS: Thirty-nine patients (Gleason score 6-10, prostate-specific antigen [PSA] 2.3-120 ng/ml) received 20 mg/kg of body weight of 5-ALA orally and underwent RP (24 endoscopic extraperitoneal, 15 open retropubic). MEASUREMENTS: A PDD-suitable laparoscopy optic (Karl-Storz GmbH, Tuttlingen, Germany) with a yellow long-pass filter was coupled to a fibre-optic light cord with an excitation light source (380-420 nm, D-Light, Karl-Storz GmbH, Tuttlingen, Germany) for fluorescence excitation of PpIX and to a PDD-suitable camera for video and photo documentation by the AIDA DVD system (Karl-Storz GmbH, Tuttlingen, Germany). RESULTS AND LIMITATIONS: There were more false-negative cases in the open group (four vs two) than in the endoscopic group but more false-positive cases in the endoscopic group (two vs none) than in the open group. The overall sensitivity and specificity were 56% and 91.6%, respectively. The sensitivity of the endoscopic cases was much higher (75% vs 38%) than for the open cases, while the specificity was higher for the open group (88.2% vs 100%). CONCLUSIONS: PDD with 5-ALA-induced PpIX during RP might be a feasible and effective method for reducing the rate of PSM. The technique seems to be more practicable during endoscopic RP rather than open RP. Further clinical studies with higher patient volumes and further development of the technique seem justified. TRIAL REGISTRATION: EudraCT: 2005-004406-93.