Corentin Warnier, Thibault Gendron, Muhammad Otabashi, Charles Vriamont and Alex Jackson were not included as authors in the original publication [...].

[18F]PARPi is currently undergoing clinical trials as a PET tracer for many applications. However, only manual radiosynthesis was reported; this has several drawbacks, including an increased risk of contamination from the operator, and the need to limit the starting activity. The automation of the previously reported protocol for [18F]PARPi synthesis is challenging, as it requires transferring microvolumes of reagents, which many platforms cannot accommodate. We report a revised, high yield, and automated protocol for the radiosynthesis of [18F]PARPi, with final doses of over 20 GBq.

Purpose Radiopharmaceuticals targeting poly(ADP-ribose) polymerase (PARP) have emerged as promising agents for cancer diagnosis and therapy. PARP enzymes are expressed in both cancerous and normal tissue. Hence, the injected mass, molar activity and potential pharmacological effects are important considerations for the use of radiolabelled PARP inhibitors for diagnostic and radionuclide therapeutic applications. Here, we performed a systematic evaluation by varying the molar activity of [ 18 F]olaparib and the injected mass of [ Total F]olaparib to investigate the effects on tumour and normal tissue uptake in two subcutaneous human glioblastoma xenograft models. Methods [ 18 F]Olaparib uptake was evaluated in the human glioblastoma models: in vitro on U251MG and U87MG cell lines, and in vivo on tumour xenograft-bearing mice, after administration of [ Total F]olaparib (varying injected mass: 0.04–8.0 µg, and molar activity: 1–320 GBq/μmol). Results Selective uptake of [ 18 F]olaparib was demonstrated in both models. Tumour uptake was found to be dependent on the injected mass of [ Total F]olaparib (µg) but not the molar activity. An injected mass of 1 μg resulted in the highest tumour uptake (up to 6.9 ± 1.3%ID/g), independent of the molar activity. In comparison, both the lower and higher injected masses of [ Total F]olaparib resulted in lower relative tumour uptake (%ID/g; P < 0.05). Ex vivo analysis of U87MG xenograft sections showed that the heterogeneity in [ 18 F]olaparib intratumoural uptake correlated with PARP1 expression. Substantial upregulation of PARP1-3 expression was observed after administration of [ Total F]olaparib (> 0.5 µg). Conclusion Our findings show that the injected mass of [ Total F]olaparib has significant effects on tumour uptake. Moderate injected masses of PARP inhibitor-derived radiopharmaceuticals may lead to improved relative tumour uptake and tumour-to-background ratio for cancer diagnosis and radionuclide therapy.

Since it was discovered that many tumor types are vulnerable to inhibition of the DNA repair machinery, research towards efficient and selective inhibitors has accelerated. Amongst other enzymes, poly(ADP-ribose)-polymerase 1 (PARP1) was identified as a key player in this process, which resulted in the development of selective PARP inhibitors (PARPi) as anti-cancer drugs. Most small molecule PARPi's exhibit high affinity for both PARP1 and PARP2. PARPi are under clinical investigation for mono- and combination therapy in several cancer types and five PARPi are now clinically approved. In parallel, radiolabeled PARPi have emerged for non-invasive imaging of PARP1 expression. PARP imaging agents have been suggested as companion diagnostics, patient selection, and treatment monitoring tools to improve the outcome of PARPi therapy, but also as stand-alone diagnostics. We give a comprehensive overview over the preclinical development of PARP imaging agents, which are mostly based on the PARPi olaparib, rucaparib, and recently also talazoparib. We also report on the current status of clinical translation, which involves a growing number of early phase trials. Additionally, this work provides an insight into promising approaches of PARP-targeted radiotherapy based on Auger and α-emitting isotopes. Furthermore, the review covers synthetic strategies for PARP-targeted imaging and therapy agents that are compatible with large scale production and clinical translation.

PurposeRadiopharmaceuticals targeting poly(ADP-ribose) polymerase (PARP) have emerged as promising agents for cancer diagnosis and therapy. PARP enzymes are expressed in both cancerous and normal tissue. Hence, the injected mass, molar activity and potential pharmacological effects are important considerations for the use of radiolabelled PARP inhibitors for diagnostic and radionuclide therapeutic applications. Here, we performed a systematic evaluation by varying the molar activity of [ 18 F]olaparib and the injected mass of [ Total F]olaparib to investigate the effects on tumour and normal tissue uptake in two subcutaneous human glioblastoma xenograft models.Methods[ 18 F]Olaparib uptake was evaluated in the human glioblastoma models: in vitro on U251MG and U87MG cell lines, and in vivo on tumour xenograft-bearing mice, after administration of [ Total F]olaparib (varying injected mass: 0.04-8.0 µg, and molar activity: 1-320 GBq/μmol).ResultsSelective uptake of [ 18 F]olaparib was demonstrated in both models. Tumour uptake was found to be dependent on the injected mass of [ Total F]olaparib (µg), but not the molar activity per sé. An injected mass of 1 μg resulted in the highest tumour uptake (up to 6.9 ± 1.3%ID/g), independent of the molar activity. In comparison, both the lower and higher injected masses of [ Total F]olaparib resulted in lower relative tumour uptake (%ID/g; P <0.05). Ex vivo analysis of U87MG xenograft sections showed that the heterogeneity in [ 18 F]olaparib intratumoural uptake correlated with PARP1 expression. Substantial upregulation of PARP1-3 expression was observed after administration of [ Total F]olaparib (>0.5 µg).ConclusionOur findings show that the injected mass of [ Total F]olaparib has significant effects on tumour uptake. Moderate injected masses of PARP inhibitor-derived radiopharmaceuticals may lead to improved relative tumour uptake and tumour-to-background ratio for cancer diagnosis and radionuclide therapy.

Background Poly (ADP-ribose) polymerase (PARP) inhibitors are extensively studied and used as anti-cancer drugs, as single agents or in combination with other therapies. Most radiotracers developed to date have been chosen on the basis of strong PARP1–3 affinity. Herein, we propose to study AZD2461, a PARP inhibitor with lower affinity towards PARP3, and to investigate its potential for PARP targeting in vivo . Methods Using the Cu-mediated 18 F-fluorodeboronation of a carefully designed radiolabelling precursor, we accessed the 18 F-labelled isotopologue of the PARP inhibitor AZD2461. Cell uptake of [ 18 F]AZD2461 in vitro was assessed in a range of pancreatic cell lines (PSN-1, PANC-1, CFPAC-1 and AsPC-1) to assess PARP expression and in vivo in xenograft-bearing mice. Blocking experiments were performed with both olaparib and AZD2461. Results [ 18 F]AZD2461 was efficiently radiolabelled via both manual and automated procedures (9 % ± 3 % and 3 % ± 1 % activity yields non-decay corrected). [ 18 F]AZD2461 was taken up in vivo in PARP1-expressing tumours, and the highest uptake was observed for PSN-1 cells (7.34 ± 1.16 %ID/g). In vitro blocking experiments showed a lesser ability of olaparib to reduce [ 18 F]AZD2461 binding, indicating a difference in selectivity between olaparib and AZD2461. Conclusion Taken together, we show the importance of screening the PARP selectivity profile of radiolabelled PARP inhibitors for use as PET imaging agents.

Positron emission tomography (PET) is a diagnostic nuclear imaging modality that relies on automated protocols to prepare agents labeled with a positron-emitting radionuclide (e.g., 18 F). In recent years, new reactions have appeared for the 18 F-labeling of agents that are difficult to access by applying traditional radiochemistry, for example those requiring 18 F incorporation into unactivated (hetero)arenes. However, automation of these new methods for translation to the clinic has progressed slowly because extensive modification of manual protocols is typically required when implementing novel 18 F-labeling methodologies within automated modules. Here, we describe the workflow that led to the automated radiosynthesis of the poly(ADP-ribose) polymerase (PARP) inhibitor [ 18 F]olaparib. First, we established a robust manual protocol to prepare [ 18 F]olaparib from the protected N -[2-(trimethylsilyl)ethoxy]methyl (SEM) arylboronate ester precursor in a 17% ± 5% ( n = 15; synthesis time, 135 min) non-decay-corrected (NDC) activity yield, with molar activity ( A m ) up to 34.6 GBq/µmol. Automation of the process, consisting of copper-mediated 18 F-fluorodeboronation followed by deprotection, was achieved on an Eckert & Ziegler Modular-Lab radiosynthesis platform, affording [ 18 F]olaparib in a 6% ± 5% ( n = 3; synthesis time, 120 min) NDC activity yield with A m up to 319 GBq/µmol.

Nine patients treated with primary signet ring cell carcinoma of the prostate were identified among 29,783 cases of prostate cancer evaluated at Mayo Clinic from January 15, 1970, until January 2, 2009. A PubMed search of the English-language literature published from January 1, 1980, to January 1, 2010, was then performed using the key words signet ring cell and prostate, identifying 42 cases. This study reviews those cases, along with the additional 9 reported herein, and evaluates clinical characteristics, histologic diagnoses, treatment modalities, and outcomes. Mean age at diagnosis was 68 years (range, 50-85 years), and mean prostate-specific antigen level was 95.3 ng/mL (range, 1.9-536.0 ng/mL; to convert to μg/L, multiply by 1). Most patients (66%) had non-stage IV carcinoma, the most common Gleason sum was 8 (33%), and mean survival was 29 months. The presence of a primary signet ring cell carcinoma of the prostate was best confirmed by negative findings on gastrointestinal work-up, a positive stain for prostate-specific acid phosphatase, and negative carcinoembryonic antigen test results.

Study Type – Therapy (case series)
Level of Evidence 4

To evaluate retrospectively whether or not previous treatment to the prostate alters the perioperative outcomes from robot-assisted radical prostatectomy (RARP) after the initial 'learning curve', as there are conflicting data on outcomes of RP in patients with previous treatment to the prostate.We retrospectively reviewed the charts of patients who had RARP between March 2005 and August 2007, and analysed demographic, perioperative variables and pathological data. In all, 510 patient charts were reviewed, identifying 24 patients with a history of previous treatment to the prostate including transurethral resection or incision of the prostate, transurethral microwave therapy, transurethral needle ablation, photoselective vaporization, simple prostatectomy, external beam radiotherapy, brachytherapy, and open bladder neck reconstruction (group 1) and 486 with no previous treatment (group 2).There was no significant difference between the groups in body mass index, clinical stage, grade or prostate volume, but the patients in group 1 were older (70 vs 65 years, P = 0.001). Outcome analysis comparing groups 1 and 2 showed an estimated blood loss of 155 vs 137 mL, length of hospital stay of 2.2 vs 1.5 days, operative duration of 200 vs 186 min and catheter time of 12 vs 8 days, respectively; only the last was statistically significant (P = 0.03). There was an 8.3% and 6.8% complication rate in groups 1 and 2, respectively, and the respective overall positive margin rate was 20.8% and 22.6%.A history of previous treatment of the prostate does not appear to compromise the perioperative outcomes of RARP.

PURPOSE:Neuroendocrine cells are ubiquitous but uncommon in benign and neoplastic prostate epithelium, and they are considered important for regulating cell growth and differentiation. The predictive value of neuroendocrine immunoreactivity for patient outcome after radical prostatectomy is uncertain. In this study we determined the expression of 2 important neuroendocrine markers, chromogranin and serotonin, in benign epithelium, primary prostate cancer and lymph node metastases, and correlated cellular expression with patient outcome. MATERIALS AND METHODS:We studied 196 patients with node positive prostate adenocarcinoma who underwent bilateral pelvic lymphadenectomy and radical prostatectomy at Mayo Clinic between 1987 and 1992. Mean followup was 6.8 years (range 0.3 to 11). The cellular expression of chromogranin and serotonin in matched samples of benign tissue, primary prostate cancer and lymph node metastases from the same patients was evaluated by immunohistochemical staining using commercially available monoclonal antibodies. Results were correlated with patient age, pathological findings (Gleason score, DNA ploidy and cancer volume) and patient outcome, including clinical progression, cancer specific and all cause survival. RESULTS:Chromogranin immunoreactivity was greater in benign prostatic epithelium and primary cancer cases (99% each) than in those of lymph node metastases (37.5%) (pairwise comparisons with metastases p <0.001). The mean incidence of immunoreactive cells in benign epithelium, primary cancer and metastases was 6% (median 5%), 6% (median 3%) and 2.2% (median 0%), respectively. Serotonin immunoreactivity was greatest in benign prostate epithelium cases (98.5%) with less in primary cancer (95%) and lymph node metastases (21.5%) (pairwise comparisons p <0.001). The mean incidence of immunoreactive cells in benign epithelium, primary cancer and metastases was 2.2% (median 3%), 2.4% (median 2%) and 0.4% (median 0%), respectively. Chromogranin expression was invariably greater than that of serotonin for all 3 diagnostic categories (p <0.0001). There was a marginally significant positive trend in the level of chromogranin expression in benign prostatic epithelium and systemic progression (p = 0.05) but no significant association with cancer specific or all cause survival (p >0.1). No significant association was observed of chromogranin expression in primary cancer or lymph node metastases with any patient outcomes (p >0.1). There was a significant association of the level of serotonin expression in benign prostatic epithelium with cancer specific survival (p = 0.03) but no significant association with systemic progression or all cause survival (p > 0.1). There were positive trends in the association of serotonin immunoreactivity in primary cancer with systemic progression (p = 0.09) and cancer specific survival (p = 0.05) but not with all cause survival (p >0.1). No significant association was observed of serotonin expression in lymph node metastases with any patient outcomes (p >0.1). CONCLUSIONS:Benign prostatic epithelium and primary prostate cancer express a significantly greater number of chromogranin and serotonin immunoreactive cells than lymph node metastases, suggesting that decreased expression of neuroendocrine markers is involved in cancer progression. However, neuroendocrine expression was marginally useful for predicting the outcome in patients with node positive prostate cancer treated with radical prostatectomy.

Male breast cancer is an uncommon disease with an incidence of approximately 1% of all breast cancers. We report a case of intracystic papillary carcinoma of the breast occurring in a 67-year-old man in whom the diagnosis was made by ultrasound-guided core biopsy. This report represents the first reported intracystic papillary carcinoma diagnosed by core biopsy and illustrates the cost-effectiveness of this technique in a male patient in providing diagnostic material and allowing for expeditious planning of definitive treatment.

High-grade prostatic intraepithelial neoplasia (PIN) is the most likely precursor of prostate cancer. The effect of radiation therapy (RT) on the prevalence of PIN is uncertain. We studied 86 patients who underwent salvage radical prostatectomy after irradiation failure at the Mayo Clinic. The prevalence, volume, multicentricity, spatial proximity to cancer, and architectural patterns of PIN were evaluated. High-grade PIN was identified in 53 (62%) of 86 prostatectomy specimens. Multiple architectural patterns were usually observed, including tufting in 87%, micropapillary in 66%, cribriform in 38%, and flat in 17%. The mean volume of PIN was 0.12 cm3 (range, 0.05-1.20 cm3). PIN was usually multicentric (70%), with a mean number of PIN foci of 2.5 (range, 1-10). Ninety-four percent of PIN foci were located within 2 mm of invasive cancer. There was no correlation between PIN and pathologic stage, surgical margin, tumor size, DNA ploidy, post-RT Gleason score, time interval from RT to biopsy-proven recurrence, postoperative prostate-specific antigen level, distant metastasis-free survival, or cancer-specific survival. Our examination of salvage radical prostatectomy specimens indicated that the prevalence and extent of PIN appeared to be reduced after RT compared to published studies of prostatectomies without prior RT.

BACKGROUND, Alterations of the p53 tumor suppressor gene are associated with advanced stage prostate carcinoma. The biologic significance of p53 nuclear accumulation in prostate cancer patients with regional lymph node metastases is uncertain.METHODS. The authors investigated p53 alterations by immunohistochemistry in 220 lymph node positive patients who were treated with radical prostatectomy, bilateral pelvic lymphadenectomy, and androgen deprivation therapy between 1987-1992 at the Mayo Clinic. The mean follow-up was 6.3 years. Tumor volume of lymph node metastases was measured using the grid method.RESULTS, p53 immunoreactivity was detected in 109 of 211 primary tumors (52%) and 83 of 144 matched regional lymph node metastases (58%); this expression was strongly concordant (correlation coefficient = 0.53; P = 0.0001). Overexpression of p53 protein in lymph node metastases was associated with distant metastasis free survival by univariate analysis (P = 0.03), but did not reach statistical significance by multivariate analysis (P = 0.07). Regional lymph node cancer volume was the single most important predictor of distant metastases after adjusting for Gleason score, DNA ploidy, and p53 expression.CONCLUSIONS. The findings of the current study suggest that assessment of biologic changes (including p53 alterations in regional lymph node metastases) could be of value in the assessment of the biologic aggressiveness of prostate carcinoma, whereas p53 expression in the primary tumor does not appear to influence patient outcome. Cancer 1999;85:2455-9. (C) 1999 American Cancer Society.

OBJECTIVES:Transurethral microwave thermotherapy is useful for the treatment of benign prostatic hyperplasia, but its effect on cancer is not documented. We analyzed the pathologic changes occurring after microwave thermotherapy in whole mount radical prostatectomy specimens from patients with cancer.METHODS:Nine patients scheduled for radical prostatectomy for clinically localized prostate cancer were treated with transurethral microwave thermotherapy (Urologix Targis System). Patients ranged in age from 64 to 72 years (mean 68). Seven patients underwent prostatectomy 4 to 90 hours after thermotherapy, and 2 other patients underwent prostatectomy 12 months after thermotherapy. Whole mount totally embedded prostates were mapped for necrosis and cancer, and the volume of each was measured by the grid method.RESULTS:Pathologic stages were T2a (n = 4), T2b (n = 4), and T3b (n = 1). The prostates from patients who underwent radical prostatectomy within 4 to 90 hours of thermotherapy had a mean prostate weight of 47.4 g (range 19.5 to 70.3). Each consistently showed hemorrhagic necrosis and tissue devitalization without significant inflammation. Necrosis involved contiguous areas of benign epithelium, stroma, and cancer without skip areas. The mean volume of necrosis was 8.8 cc (range 1.4 to 17.8), and the mean percentage of the prostate involved by necrosis was 22% (range 3% to 39%). The necrosis was symmetric around the urethra in 6 of 7 cases. Urethral dilation was observed in 3 patients, and the mean maximum radial distance of necrotic tissue was 1.4 cm (range 0.6 to 1.8). Necrotic change was noted in 80% to 100% of the volume of cancer in 4 cases, 40% to 60% in 2 cases, and 5% in 1 case. The prostates from the 2 patients who underwent radical prostatectomy 12 months after thermotherapy had a mean weight of 88 g (55 and 121 g, respectively). Each showed periurethral fibrosis, nonspecific chronic inflammation, and squamous metaplasia of the urothelium. The mean volume of necrosis remaining was 0.2 cc. The mean percentage of the prostate involved by necrosis 1 year after thermotherapy was less than 1%. There was some reabsorption of dead tissue. The mean maximum radial distance of the necrotic tissue was 0.4 cm (0.2 and 0.7 cm, respectively). The prostatic urethra had viable and partially denuded urothelium in all cases.CONCLUSIONS:Microwave thermotherapy is clinically useful for ablation of benign prostate and cancer contiguous to the urethra, resulting in hemorrhagic necrosis with minimal damage to the urethra. There was no apparent differential morphologic sensitivity of benign prostatic tissue, hyperplastic tissue, or cancer to thermotherapy.

Extraprostatic extension (EPE) is an unfavorable prognostic factor in patients with prostate carcinoma. Prior studies have reported the linear extent of EPE measured circumferentially along the edge of the prostate. In this study, the authors defined and evaluated a novel measure of EPE in a large series of radical prostatectomy specimens. These results have important clinical implications in the management of localized prostate carcinoma by brachytherapy and other modalities.

PURPOSE:Androgen receptors are present in virtually all epithelial cells of the prostate, including benign epithelium, high grade prostatic intraepithelial neoplasia and cancer. However, there have been variable results regarding the clinical significance of cells expressing androgen receptors in prostate cancer. We evaluated the predictive accuracy of androgen receptor expression in prostatic intraepithelial neoplasia and cancer for clinical progression and survival in patients with organ confined prostate cancer treated with radical prostatectomy. MATERIALS AND METHODS:The study consisted of 172 previously untreated patients who underwent radical prostatectomy at our clinic between 1987 and 1991 with intermediate to high grade (Gleason score 6 to 9), pathological stage T2 cancer and negative surgical margins. Mean followup was 7.4 years (range 1.2 to 10.1). Mouse monoclonal anti-human androgen receptor antibody was used for immunohistochemical studies on select tissue sections from each case. We counted 100 nuclei from 3 separate areas of benign epithelium, prostatic intraepithelial neoplasia and cancer (total 300 nuclei for each diagnostic category) for each case. Mean nuclear androgen receptor expression was determined from the mean of the individual cases for each diagnostic category. Intensity was also evaluated using a subjective scale from 0 (no staining) to 3 (strong staining). We determined the correlation of clinical progression and the number of androgen receptor immunoreactive prostatic intraepithelial neoplasia or cancer nuclei, and then performed multivariate analysis which included deoxyribonucleic acid ploidy, radical prostatectomy Gleason score and preoperative serum prostate specific antigen using the Cox proportional hazards model. Progression was defined as a positive biopsy, positive bone scan or biochemical progression (postoperative serum prostate specific antigen greater than 0.2 ng./ml.). RESULTS:Nuclear immunoreactivity for androgen receptors was observed in all cases. Mean percent of immunoreactive nuclei was higher in benign epithelium than in prostatic intraepithelial neoplasia and cancer (56.3, 46.1 and 53.6%, respectively, pairwise comparisons p <0.05 for each pair). With rare exceptions, basal cells in benign epithelium and prostatic intraepithelial neoplasia were negative. The most intense nuclear staining was observed in benign epithelium. Immunoreactivity was also faint but detectable in the cytoplasm in prostatic intraepithelial neoplasia but not in benign epithelium or cancer. Mean number of androgen receptor immunoreactive nuclei in prostatic intraepithelial neoplasia and cancer was not a significant univariate or multivariate predictor of clinical and/or biochemical progression, or all cause survival (all p >0.05). CONCLUSIONS:Androgen receptor expression was present in all cases of benign epithelium, prostatic intraepithelial neoplasia and cancer. The greatest extent and intensity of expression were observed in benign epithelium, with about half of the nuclei showing intense immunoreactivity. The number of androgen receptor immunoreactive nuclei in prostatic intraepithelial neoplasia and cancer in patients with organ confined prostate cancer treated with radical prostatectomy was not predictive of progression or survival.