Ectopic ACTH Cushing's syndrome caused by a large-cell neuroendocrine lung carcinoma responding to desmopressin

Ectopic adrenocorticotrophic hormone (ACTH) secretion (EAS) is a rare cause of ACTH-dependent Cushing's syndrome (CS), most often caused by a thoracic neuroendocrine tumor (NET). Large-cell neuroendocrine carcinomas (LCNEC) with EAS are rare and usually present a more severe ACTH secretion and hypercortisolism. We report a 44-year-old non-smoker man, who presented clinical and biochemical evidence of ACTH-dependent CS. Desmopressin 10 μg i.v. produced a 157% increase in ACTH and a 25% increase in cortisol from baseline; there was no stimulation of ACTH or cortisol during the corticotropin-releasing hormone (CRH) test and no suppression with high dose dexamethasone. Pituitary MRI identified a 5 mm lesion, but inferior petrosal venous sinus sampling under desmopressin did not identify a central ACTH source. Thorax and abdominal imaging identified a left lung micronodule. Surgery confirmed a lung LCNEC with strongly positive ACTH immunohistochemistry (IHC) in the primary and lymph node metastasis. The patient was in CS remission after surgery and adjuvant chemotherapy but developed a recurrence 9.5 years later, with LCNEC pulmonary left hilar metastases, ectopic CS, and positive ACTH IHC. This is the first report of LCNEC, with morphologic feature of carcinoid tumor of the lung with ectopic ACTH stimulated by desmopressin. Long delay prior to metastatic recurrence indicates relatively indolent NET. This case report indicates that response to desmopressin, which usually occurs in Cushing's disease or benign NETs, can occur in malignant LCNEC.

Identification of Morphologic Criteria Associated with Biochemical Recurrence in Intraductal Carcinoma of the Prostate

Intraductal carcinoma of the prostate (IDC-P) is an aggressive subtype of prostate cancer strongly associated with an increased risk of biochemical recurrence (BCR). However, approximately 40% of men with IDC-P remain BCR-free five years after radical prostatectomy. In this retrospective multicenter study, we aimed to identify histologic criteria associated with BCR for IDC-P lesions. A total of 108 first-line radical prostatectomy specimens were reviewed. In our test cohort (n = 39), presence of larger duct size (>573 µm in diameter), cells with irregular nuclear contours (CINC) (≥5 CINC in two distinct high-power fields), high mitotic score (>1.81 mitoses/mm2), blood vessels, and comedonecrosis were associated with early BCR (<18 months) (p < 0.05). In our validation cohort (n = 69), the presence of CINC or blood vessels was independently associated with an increased risk of BCR (hazard ratio [HR] 2.32, 95% confidence interval [CI] 1.09-4.96, p = 0.029). When combining the criteria, the presence of any CINC, blood vessels, high mitotic score, or comedonecrosis showed a stronger association with BCR (HR 2.74, 95% CI 1.21-6.19, p = 0.015). Our results suggest that IDC-P can be classified as low versus high-risk of BCR. The defined morphologic criteria can be easily assessed and should be integrated for clinical application following validation in larger cohorts.

Dimensional reduction based on peak fitting of Raman micro spectroscopy data improves detection of prostate cancer in tissue specimens

SIGNIFICANCE

Prostate cancer is the most common cancer among men. An accurate diagnosis of its severity at detection plays a major role in improving their survival. Recently, machine learning models using biomarkers identified from Raman micro-spectroscopy discriminated intraductal carcinoma of the prostate (IDC-P) from cancer tissue with a ≥85  %   detection accuracy and differentiated high-grade prostatic intraepithelial neoplasia (HGPIN) from IDC-P with a ≥97.8  %   accuracy.

AIM

To improve the classification performance of machine learning models identifying different types of prostate cancer tissue using a new dimensional reduction technique.

APPROACH

A radial basis function (RBF) kernel support vector machine (SVM) model was trained on Raman spectra of prostate tissue from a 272-patient cohort (Centre hospitalier de l'Université de Montréal, CHUM) and tested on two independent cohorts of 76 patients [University Health Network (UHN)] and 135 patients (Centre hospitalier universitaire de Québec-Université Laval, CHUQc-UL). Two types of engineered features were used. Individual intensity features, i.e., Raman signal intensity measured at particular wavelengths and novel Raman spectra fitted peak features consisting of peak heights and widths.

RESULTS

Combining engineered features improved classification performance for the three aforementioned classification tasks. The improvements for IDC-P/cancer classification for the UHN and CHUQc-UL testing sets in accuracy, sensitivity, specificity, and area under the curve (AUC) are (numbers in parenthesis are associated with the CHUQc-UL testing set): +4  %   (+8  %  ), +7  %   (+9  %  ), +2  %   (6%), +9 (+9) with respect to the current best models. Discrimination between HGPIN and IDC-P was also improved in both testing cohorts: +2.2  %   (+1.7  %  ), +4.5  %   (+3.6  %  ), +0  %   (+0  %  ), +2.3 (+0). While no global improvements were obtained for the normal versus cancer classification task [+0  %   (-2  %  ), +0  %   (-3  %  ), +2  %   (-2  %  ), +4 (+3)], the AUC was improved in both testing sets.

CONCLUSIONS

Combining individual intensity features and novel Raman fitted peak features, improved the classification performance on two independent and multicenter testing sets in comparison to using only individual intensity features.

Canadian ROS proto-oncogene 1 study (CROS) for multi-institutional implementation of ROS1 testing in non-small cell lung cancer

Patients with non-small cell lung cancer (NSCLC) harboring ROS proto-oncogene 1 (ROS1) gene rearrangements show dramatic response to the tyrosine kinase inhibitor (TKI) crizotinib. Current best practice guidelines recommend that all advanced stage non-squamous NSCLC patients be also tested for ROS1 gene rearrangements. Several studies have suggested that ROS1 immunohistochemistry (IHC) using the D4D6 antibody may be used to screen for ROS1 fusion positive lung cancers, with assays showing high sensitivity but moderate to high specificity. A break apart fluorescence in situ hybridization (FISH) test is then used to confirm the presence of ROS1 gene rearrangement. The goal of Canadian ROS1 (CROS) study was to harmonize ROS1 laboratory developed testing (LDT) by using IHC and FISH assays to detect ROS1 rearranged lung cancers across Canadian pathology laboratories. Cell lines expressing different levels of ROS1 (high, low, none) were used to calibrate IHC protocols after which participating laboratories ran the calibrated protocols on a reference set of 24 NSCLC cases (9 ROS1 rearranged tumors and 15 ROS1 non-rearranged tumors as determined by FISH). Results were compared using a centralized readout. The stained slides were evaluated for the cellular localization of staining, intensity of staining, the presence of staining in non-tumor cells, the presence of non-specific staining (e.g. necrosis, extracellular mater, other) and the percent positive cells. H-score was also determined for each tumor. Analytical sensitivity and specificity harmonization was achieved by using low limit of detection (LOD) as either any positivity in the U118 cell line or H-score of 200 with the HCC78 cell line. An overall diagnostic sensitivity and specificity of up to 100% and 99% respectively was achieved for ROS1 IHC testing (relative to FISH) using an adjusted H-score readout on the reference cases. This study confirms that LDT ROS1 IHC assays can be highly sensitive and specific for detection of ROS1 rearrangements in NSCLC. As NSCLC can demonstrate ROS1 IHC positivity in FISH-negative cases, the degree of the specificity of the IHC assay, especially in highly sensitive protocols, is mostly dependent on the readout cut-off threshold. As ROS1 IHC is a screening assay for a rare rearrangements in NSCLC, we recommend adjustment of the readout threshold in order to balance specificity, rather than decreasing the overall analytical and diagnostic sensitivity of the protocols.

A randomized noninferiority trial comparing the diagnostic yield of the 25G ProCore needle to the standard 25G needle in suspicious pancreatic lesions

Background and Objectives

The aim of the study was to perform the first randomized trial comparing the diagnostic yield, bloodiness, and cellularity of the 25G standard needle (25S) and the 25G ProCore™ needle (25P).

Materials and Methods

All patients referred to the tertiary care referral center for EUS guided fine-needle aspiration (EUS-FNA) of suspicious solid pancreatic lesions were eligible. EUS-FNA was performed in each lesion with both 25S and 25P needles (the choice of the first needle was randomized), using a multipass sampling pattern, without stylet or suction. Rapid on-site evaluation was used when possible. Pap-stained slides were read by a single experienced cytopathologist, blinded to the needle type.

Results

One hundred and forty-three patients were recruited. Samples were positive for cancer in 122/143 (85.3%) with the 25S needle versus 126/143 (88.1%) with the 25P needle, negative in 17/143 (11.9%) with the 25S needle versus 13/143 (9.1%) with the 25P needle, and suspicious in 4/143 (2.8%) with each needle. There was no difference in any outcome based on the type of the first needle. No carryover effect was detected (P = 0.214; NS). Cumulative logistic regression analyses showed no associations between the type of needle and diagnostic yield for cancer, cellularity, or bloodiness. The difference in the yield for cancer was 2.9% (-4.2; 10.1%); with the confidence interval upper within the predetermined noninferiority margin of 15%.

Conclusion

The 25S needle is noninferior to the 25P needle for diagnosing cancer in suspicious pancreatic lesions.

Identification of intraductal carcinoma of the prostate on tissue specimens using Raman micro-spectroscopy: A diagnostic accuracy case-control study with multicohort validation

BACKGROUND

Prostate cancer (PC) is the most frequently diagnosed cancer in North American men. Pathologists are in critical need of accurate biomarkers to characterize PC, particularly to confirm the presence of intraductal carcinoma of the prostate (IDC-P), an aggressive histopathological variant for which therapeutic options are now available. Our aim was to identify IDC-P with Raman micro-spectroscopy (RμS) and machine learning technology following a protocol suitable for routine clinical histopathology laboratories.

METHODS AND FINDINGS

We used RμS to differentiate IDC-P from PC, as well as PC and IDC-P from benign tissue on formalin-fixed paraffin-embedded first-line radical prostatectomy specimens (embedded in tissue microarrays [TMAs]) from 483 patients treated in 3 Canadian institutions between 1993 and 2013. The main measures were the presence or absence of IDC-P and of PC, regardless of the clinical outcomes. The median age at radical prostatectomy was 62 years. Most of the specimens from the first cohort (Centre hospitalier de l'Université de Montréal) were of Gleason score 3 + 3 = 6 (51%) while most of the specimens from the 2 other cohorts (University Health Network and Centre hospitalier universitaire de Québec-Université Laval) were of Gleason score 3 + 4 = 7 (51% and 52%, respectively). Most of the 483 patients were pT2 stage (44%-69%), and pT3a (22%-49%) was more frequent than pT3b (9%-12%). To investigate the prostate tissue of each patient, 2 consecutive sections of each TMA block were cut. The first section was transferred onto a glass slide to perform immunohistochemistry with H&E counterstaining for cell identification. The second section was placed on an aluminum slide, dewaxed, and then used to acquire an average of 7 Raman spectra per specimen (between 4 and 24 Raman spectra, 4 acquisitions/TMA core). Raman spectra of each cell type were then analyzed to retrieve tissue-specific molecular information and to generate classification models using machine learning technology. Models were trained and cross-validated using data from 1 institution. Accuracy, sensitivity, and specificity were 87% ± 5%, 86% ± 6%, and 89% ± 8%, respectively, to differentiate PC from benign tissue, and 95% ± 2%, 96% ± 4%, and 94% ± 2%, respectively, to differentiate IDC-P from PC. The trained models were then tested on Raman spectra from 2 independent institutions, reaching accuracies, sensitivities, and specificities of 84% and 86%, 84% and 87%, and 81% and 82%, respectively, to diagnose PC, and of 85% and 91%, 85% and 88%, and 86% and 93%, respectively, for the identification of IDC-P. IDC-P could further be differentiated from high-grade prostatic intraepithelial neoplasia (HGPIN), a pre-malignant intraductal proliferation that can be mistaken as IDC-P, with accuracies, sensitivities, and specificities > 95% in both training and testing cohorts. As we used stringent criteria to diagnose IDC-P, the main limitation of our study is the exclusion of borderline, difficult-to-classify lesions from our datasets.

CONCLUSIONS

In this study, we developed classification models for the analysis of RμS data to differentiate IDC-P, PC, and benign tissue, including HGPIN. RμS could be a next-generation histopathological technique used to reinforce the identification of high-risk PC patients and lead to more precise diagnosis of IDC-P.

Canadian Multicenter Project on Standardization of Programmed Death-Ligand 1 Immunohistochemistry 22C3 Laboratory-Developed Tests for Pembrolizumab Therapy in NSCLC

INTRODUCTION

The programmed death-ligand 1 (PD-L1) immunohistochemistry (IHC) assay is used to select patients for first or second-line pembrolizumab monotherapy in NSCLC. The PD-L1 IHC 22C3 pharmDx assay requires an Autostainer Link 48 instrument. Laboratories without this stainer have the option to develop a highly accurate 22C3 IHC laboratory-developed test (LDT) on other instruments. The Canadian 22C3 IHC LDT validation project was initiated to harmonize the quality of PD-L1 22C3 IHC LDT protocols across 20 Canadian pathology laboratories.

METHODS

Centrally optimized 22C3 LDT protocols were distributed to participating laboratories. The LDT results were assessed against results using reference PD-L1 IHC 22C3 pharmDx. Analytical sensitivity and specificity were assessed using cell lines with varying PD-L1 expression levels (phase 1) and IHC critical assay performance controls (phase 2B). Diagnostic sensitivity and specificity were assessed using whole sections of 50 NSCLC cases (phase 2A) and tissue microarrays with an additional 50 NSCLC cases (phase 2C).

RESULTS

In phase 1, 80% of participants reached acceptance criteria for analytical performance in the first attempt with disseminated protocols. However, in phase 2A, only 40% of participants reached the desired diagnostic accuracy for both 1% and 50% tumor proportion score cutoff. In phase 2B, further protocol modifications were conducted, which increased the number of successful laboratories to 75% in phase 2C.

CONCLUSIONS

It is possible to harmonize highly accurate 22C3 LDTs for both 1% and 50% tumor proportion score in NSCLC across many laboratories with different platforms. However, despite a centralized approach, diagnostic validation of predictive IHC LDTs can be challenging and not always successful.

Wide-field optical spectroscopy system integrating reflectance and spatial frequency domain imaging to measure attenuation-corrected intrinsic tissue fluorescence in radical prostatectomy specimens

The development of a multimodal optical imaging system is presented that integrates endogenous fluorescence and diffuse reflectance spectroscopy with single-wavelength spatial frequency domain imaging (SFDI) and surface profilometry. The system images specimens at visible wavelengths with a spatial resolution of 70 µm, a field of view of 25 cm² and a depth of field of ∼1.5 cm. The results of phantom experiments are presented demonstrating the system retrieves absorption and reduced scattering coefficient maps using SFDI with <6% reconstruction errors. A phase-shifting profilometry technique is implemented and the resulting 3-D surface used to compute a geometric correction ensuring optical properties reconstruction errors are maintained to <6% in curved media with height variations <20 mm. Combining SFDI-computed optical properties with data from diffuse reflectance spectra is shown to correct fluorescence using a model based on light transport in tissue theory. The system is used to image a human prostate, demonstrating its ability to distinguish prostatic tissue (anterior stroma, hyperplasia, peripheral zone) from extra-prostatic tissue (urethra, ejaculatory ducts, peri-prostatic tissue). These techniques could be integrated in robotic-assisted surgical systems to enhance information provided to surgeons and improve procedural accuracy by minimizing the risk of damage to extra-prostatic tissue during radical prostatectomy procedures and eventually detect residual cancer.

Crizotinib inhibition of ROS1-positive tumours in advanced non-small-cell lung cancer: a Canadian perspective

The ros1 kinase is an oncogenic driver in non-small-cell lung cancer (nsclc). Fusion events involving the ROS1 gene are found in 1%-2% of nsclc patients and lead to deregulation of a tyrosine kinase-mediated multi-use intracellular signalling pathway, which then promotes the growth, proliferation, and progression of tumour cells. ROS1 fusion is a distinct molecular subtype of nsclc, found independently of other recognized driver mutations, and it is predominantly identified in younger patients (<50 years of age), women, never-smokers, and patients with adenocarcinoma histology. Targeted inhibition of the aberrant ros1 kinase with crizotinib is associated with increased progression-free survival (pfs) and improved quality-of-life measures. As the sole approved treatment for ROS1-rearranged nsclc, crizotinib has been demonstrated, through a variety of clinical trials and retrospective analyses, to be a safe, effective, well-tolerated, and appropriate treatment for patients having the ROS1 rearrangement. Canadian physicians endorse current guidelines which recommend that all patients with nonsquamous advanced nsclc, regardless of clinical characteristics, be tested for ROS1 rearrangement. Future integration of multigene testing panels into the standard of care could allow for efficient and cost-effective comprehensive testing of all patients with advanced nsclc. If a ROS1 rearrangement is found, treatment with crizotinib, preferably in the first-line setting, constitutes the standard of care, with other treatment options being investigated, as appropriate, should resistance to crizotinib develop.

Retrospective study on the benefit of adjuvant radiotherapy in men with intraductal carcinoma of prostate

Background

Intraductal carcinoma of the prostate (IDC-P) is an independent biomarker of recurrence and survival with particular treatment response, yet no study has tested its response to radiotherapy. The aim of our project was to test the impact of adjuvant radiotherapy (ART) in patients with localized to locally advanced prostate cancer (PC) and IDC-P.

Materials and methods

We performed a retrospective study of men with pT2-T3 PC treated by radical prostatectomy (RP) with or without ART, from two centres (1993–2015). Exclusion criteria were the use of another type of treatment prior to biochemical recurrence (BCR), and detectable prostate- specific antigen (PSA) following RP or ART. Primary outcome was BCR (2 consecutive PSA ≥ 0.2 ng/ml). Patients were grouped by treatment (RP_only/RP + ART), IDC-P status, and presence of high-risk features (HRF: Grade Groups 4–5, positive margins, pT3 stage).

Results

We reviewed 293 RP specimens (median follow-up 99 months, 69 BCR). Forty-eight patients (16.4%) were treated by RP + ART. Multivariate Cox regression for BCR indicated that IDC-P had the strongest impact (hazard ratio [HR] = 2.39, 95% confidence interval [CI]:1.44–3.97), while ART reduced the risk of BCR (HR = 0.38, 95%CI: 0.17–0.85). Other HRF were all significant except for pT3b stage. IDC-P[+] patients who did not receive ART had the worst BCR-free survival (log-rank P = 0.023). Furthermore, IDC-P had the same impact on BCR-free survival as ≥1 HRF (log-rank P = 0.955).

Conclusion

Men with IDC-P who did not receive ART had the highest BCR rates, and IDC-P had the same impact as ≥1 HRF, which are often used as ART indications. Once validated, ART should be considered in patients with IDC-P.

Electronic supplementary material

The online version of this article (10.1186/s13014-019-1267-3) contains supplementary material, which is available to authorized users.

Canadian perspectives: update on inhibition of ALK-positive tumours in advanced non-small-cell lung cancer

Background

Inhibition of the anaplastic lymphoma kinase (alk) oncogenic driver in advanced non-small-cell lung carcinoma (nsclc) improves survival. In 2015, Canadian thoracic oncology specialists published a consensus guideline about the identification and treatment of ALK-positive patients, recommending use of the alk inhibitor crizotinib in the first line. New scientific literature warrants a consensus update.

Methods

Clinical trials of alk inhibitor were reviewed to assess benefits, risks, and implications relative to current Canadian guidance in patients with ALK-positive nsclc.

Results

Randomized phase iii trials have demonstrated clinical benefit for single-agent alectinib and ceritinib used in treatment-naïve patients and as second-line therapy after crizotinib. Phase ii trials have demonstrated activity for single-agent brigatinib and lorlatinib in further lines of therapy. Improved responses in brain metastases were observed for all second- and next/third-generation alk tyrosine kinase inhibitors in patients progressing on crizotinib. Canadian recommendations are therefore revised as follows:■ Patients with advanced nonsquamous nsclc have to be tested for the presence of an ALK rearrangement.■ Treatment-naïve patients with ALK-positive disease should initially be offered single-agent alectinib or ceritinib, or both sequentially.■ Crizotinib-refractory patients should be treated with single-agent alectinib or ceritinib, or both sequentially.■ Further treatments could include single-agent brigatinib or lorlatinib, or both sequentially.■ Patients progressing on alk tyrosine kinase inhibitors should be considered for pemetrexed-based chemotherapy.■ Other systemic therapies should be exhausted before immunotherapy is considered.

Summary

Multiple lines of alk inhibition are now recommended for patients with advanced nsclc with an ALK rearrangement.

The impact of intraductal carcinoma of the prostate on the site and timing of recurrence and cancer-specific survival

BACKGROUND

To investigate the effect of intraductal carcinoma of the prostate (IDC-P) in radical prostatectomy (RP) specimens in the context of the site of recurrence, time to recurrence, and cancer-specific survival in two academic cohorts of locally, regionally, or distantly recurrent prostate cancer.

METHODS

Our cohort included men enrolled into two academic tissue repositories from 1993 to 2011, who were treated with first-line RP who later experienced local recurrence, regional recurrence, or distant metastasis (together termed clinical recurrence, CR). RP material was reviewed to identify IDC-P and to update grading to current standards. The primary endpoint was the initial location of CR. Secondary endpoints included time to CR and cancer-specific survival. Pearson's chi-square, Welch's t-test, Mann-Whitney U test and Fisher's exact test were performed for univariate analyses. Multinomial logistic regression was used for multivariate analyses. Cancer-specific survival was analyzed with the generalized Wilcoxon test and Cox regression.

RESULTS

Eighty-five patients with CR were included in the analysis. IDC-P was present in 78.5% of patients from Center 1 and 70.0% from Center 2 (P = 0.547). IDC-P was independently associated with distant metastasis at initial CR (multivariate odds ratio = 6.27, P = 0.015). IDC-P status did not affect time to recurrence; median survival without recurrence was at 53 months for IDC-P(+) and at 50 months for IDC-P(-) (P = 0.441). Distant metastases at the initial CR event had a 36% reduction of cancer-specific survival compared to local recurrences (P = 0.007). Additionally, prostatic-bed radiotherapy (adjuvant or salvage for biochemical recurrence before distant metastasis) was associated with a 25% reduction in cancer-specific mortality compared to no radiotherapy (P = 0.023). Similar reduction in cancer-specific mortality was observed in the subgroup of patients with distant metastasis and IDC-P when treated with radiotherapy (29%, P = 0.050).

CONCLUSIONS

In our cohort, presence of IDC-P was an independent factor for distant metastasis at initial CR, but did not have a significant impact on time to CR. Furthermore, metastatic patients showed statistically reduced cancer-specific mortality when treated with radiotherapy. This reduction in cancer-specific mortality was also identified in patients with IDC-P. Future large scale validation studies should take into account the presence of IDC-P and confirm its impact on disease progression.

Endoscopic ultrasound-guided FNA of pelvic lesions: A large single-center experience

BACKGROUND

Pelvic endoscopic ultrasound-guided fine-needle aspiration (PEUS-FNA) of rectal or perirectal lesions is safe, minimally invasive, and well tolerated. It provides valuable information, which can greatly influence patient management. Herein, the authors present what to their knowledge is the largest series to date of PEUS-FNA.

METHODS

PEUS-FNA specimens were retrieved from the archives of the study institution from January 2001 to March 2015. Only patients with solid pelvic lesions were examined. The cytopathology findings, immunohistochemistry, corresponding histology, and clinical data were collected. For analysis of accuracy, atypical or suspicious results were classified as "negative." The sensitivity and specificity of PEUS-FNA were calculated in a subset of patients with available surgical pathology.

RESULTS

A total of 127 cases meeting the current study criteria were obtained from patients who underwent PEUS-FNA at the study institution between January 2001 and March 2015. The mean age of the patients was 60 years, and 53% were female. Pelvic lesions were comprised of 72% masses and 28% lymph nodes, with a mean mass diameter of 27.38 mm (range, 5-100 mm). PEUS-FNA was positive for malignancy in 45% of cases, atypical/suspicious in 4.7% of cases, and negative for malignancy in 50.3% of cases. Surgical pathology was available for 44 patients. PEUS-FNA demonstrated 89.3% sensitivity, 100% specificity, a diagnostic accuracy of 93.2%, a positive predictive value of 100%, and a negative predictive value of 84.2%. No complications were noted.

CONCLUSIONS

PEUS-FNA is safe and effective for the investigation of pelvic lesions. Cancer Cytopathol 2016;124:836-41. © 2016 American Cancer Society.

Canadian consensus: inhibition of ALK-positive tumours in advanced non-small-cell lung cancer

Anaplastic lymphoma kinase (alk) is an oncogenic driver in non-small-cell lung cancer (nsclc). Chromosomal rearrangements involving the ALK gene occur in up to 4% of nonsquamous nsclc patients and lead to constitutive activation of the alk signalling pathway. ALK-positive nsclc is found in relatively young patients, with a median age of 50 years. Patients frequently have brain metastasis. Targeted inhibition of the alk pathway prolongs progression-free survival in patients with ALK-positive advanced nsclc. The results of several recent clinical trials confirm the efficacy and safety benefit of crizotinib and ceritinib in this population. Canadian oncologists support the following consensus statement: All patients with advanced nonsquamous nsclc (excluding pure neuroendocrine carcinoma) should be tested for the presence of an ALK rearrangement. If an ALK rearrangement is present, treatment with a targeted alk inhibitor in the first-line setting is recommended. As patients become resistant to first-generation alk inhibitors, other treatments, including second-generation alk inhibitors can be considered.

PTEN loss and ERG protein expression are infrequent in prostatic ductal adenocarcinomas and concurrent acinar carcinomas

BACKGROUND

Prostatic ductal adenocarcinoma is an unusual and aggressive morphologic subtype of prostate cancer. PTEN gene deletion and ERG gene rearrangement are among the most common genomic changes in acinar prostate cancers. Though ductal adenocarcinoma most commonly occurs with synchronous usual-type acinar adenocarcinoma, little is known about the molecular phenotype of these mixed tumors.

METHODS

We used genetically validated immunohistochemistry (IHC) assays to assess PTEN and ERG status in a group of 37 surgically treated ductal adenocarcinomas and 18 synchronous acinar adenocarcinomas where we have previously reported ERG gene rearrangement status by fluorescence in situ hybridization (FISH). A group of 34 stage and grade-matched pure acinar adenocarcinoma cases was studied as a control.

RESULTS

ERG IHC was highly concordant with ERG FISH results, with 100% (36/36) concordance among ductal adenocarcinomas and 91% (31/34) concordance among 34 pure acinar carcinomas. Similar to previous FISH results, ERG expression by IHC was significantly less common among ductal adenocarcinomas (11% or 4/37) and their synchronous acinar tumors (6% or 1/18) compared to matched pure acinar adenocarcinoma cases (50% or 17/34; P = 0.0005 and 0.002, respectively). PTEN loss by IHC was also less common among ductal adenocarcinomas (18% or 6/34) and their synchronous acinar tumors (22% or 4/18) compared to matched pure acinar carcinomas (50% or 17/34; P = 0.01 and 0.08, respectively). As expected, PTEN loss was enriched among ERG positive compared to ERG-negative tumors in the pure acinar tumor control group (2.5-fold enrichment; P = 0.04) however this was not observed among the ductal adenocarcinomas (1.5 fold enrichment; P = NS). Of ductal adenocarcinomas with an evaluable synchronous acinar component, ERG status was concordant in 94% (17/18) and PTEN status was concordant in 94% (16/17).

CONCLUSIONS

Based on PTEN and ERG, ductal adenocarcinomas and their concurrent acinar carcinomas may be clonally related in some cases and show important molecular differences from pure acinar carcinoma.

GSTP1 promoter methylation is associated with recurrence in early stage prostate cancer

PURPOSE

Recurrent prostate cancer remains a major problem. Staging, grading and prostate specific antigen level at surgery are helpful but still imperfect predictors of recurrence. For this reason there is an imperative need for additional biomarkers that add to the prediction of currently used prognostic factors.

MATERIALS AND METHODS

We evaluated the extent of promoter methylation of genes previously reported as aberrantly methylated in prostate cancer (AIM1, APC, CCND2, GPX3, GSTP1, MCAM, RARβ2, SSBP2 and TIMP3) by quantitative fluorogenic methylation-specific polymerase chain reaction. We used cancer tissue from a nested case-control study of 452 patients surgically treated for prostate cancer. Recurrence cases and controls were compared and the association between methylation extent and recurrence risk was estimated by logistic regression adjusting for patient age at prostatectomy, prostatectomy year, stage, grade, surgical margins and preprostatectomy prostate specific antigen. All statistical tests were 2-sided with p ≤0.05 considered statistically significant.

RESULTS

The extent of GSTP1 methylation was higher in patients with recurrence than in controls (p = 0.01), especially patients with early disease, ie organ confined or limited extraprostatic extension (p = 0.001). After multivariate adjustment GSTP1 promoter methylation at or above the median was associated with an increased risk of recurrence, including in men with early disease (each p = 0.05).

CONCLUSIONS

Greater GSTP1 promoter methylation in cancer tissue was independently associated with the risk of recurrence in patients with early prostate cancer. This suggests that GSTP1 promoter methylation may be a potential tissue based recurrence marker.

Activation of mammalian target of rapamycin signaling pathway markers in minute adenocarcinoma of the prostate

OBJECTIVE

To asses the mammalian target of rapamycin (mTOR) pathway in minute prostatic adenocarcinoma on the basis of the previously reported role of phosphatase and tensin homolog (PTEN) inactivation and mTOR pathway activation as a negative prognosticator in prostatic cancer.

METHODS

Tissue microarrays were constructed from 42 consecutive radical prostatectomy specimens with minute prostatic adenocarcinoma. Standard immunohistochemistry analysis for mTOR pathway members PTEN, phos-S6, phos-4E-BP1, phos-mTOR, phos-AKT, p27, and ERG was performed. For all markers, histologic expression score was calculated as the sum of intensity × extent of expression. In addition, for PTEN, presence of "markedly decreased" expression (any focal absence of expression) was also assessed. Expression status of all biomarkers was compared between tumor and paired benign tissue. Intercorrelation among markers was also performed.

RESULTS

PTEN expression was seen in all 36 evaluable minute prostatic adenocarcinoma. Cytoplasmic phos-S6 was present in 32 of 36 tumors (89%). phos-S6 expression levels were higher in tumors compared with paired benign tissue (P = .007). Cytoplasmic and nuclear phos-4E-BP1 was present in all 34 evaluable tumors. phos-4E-BP1 was significantly higher in cancer compared with normal tissue (P <.0001). Only a minority of tumors demonstrating higher phos-S6 expression and phos-4E-BP1 (2 of 32 and 2 of 34, respectively) had associated "markedly decreased" PTEN expression.

CONCLUSION

We found evidence of activation of mTOR pathway in minute prostatic adenocarcinoma that appears to be unrelated to "markedly decreased" PTEN expression. The latter finding suggests an alternative signaling mechanism controlling mTOR activation in minute prostate carcinoma.

NSCLC driver mutations in the Quebec population: Epidemiologic and clinical evaluation

e22159

Background: Recent advances in lung cancer treatment embrace the recognition of molecular pathways implicated in its pathogenicity, paving the path to personalized therapies. We conducted a retrospective analysis to characterize the molecular features of the population treated for non-squamous non-small cell lung cancer (NS-NSCLC) in the province of Quebec. Methods: 622 patients with NS-NSCLC and adequate tumor blocks, treated at the CHUM between 2006 and 2008, were included. All samples were tested for ALK translocations (by IHC and FISH), EGFR classical exon 19 and 21 mutations by PCR (fragment analysis and qPCR) and for KRAS codon 12 and 13 mutations by mismatch PCR-RFLP. Molecular features were matched to demographic characteristics and clinical outcomes. Results: So far, complete results are available for 153 patients. Considering the amount of tumor tissue available, this population is largely represented by patients with local or loco-regional disease (n= 140, 91.5%). A minority of patients (10.3%) was never or light smokers (< 10 pack-yrs). Only 2 patients (1.3%) were of Asian descent. The following table depicts the outcomes of this cohort of patients segregated according to mutation status and extent of disease. Conclusions: ALK rearrangements were not identified in this unselected NS-NSCLC population characterized by localized disease and strong smoking history. ALK translocation prevalence in different populations is likely to be largely influenced by its tumor stage distribution, tobacco exposure and the use of selection criteria for molecular testing. An expanded cohort of patients will be presented at the meeting. [Table: see text]

Canadian ALK (CALK): A pan-Canadian multicenter study to optimize and standardize ALK immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) for ALK gene rearrangements

8096

Background: ALK gene rearrangement (ALK+) has been found in 3-5% of advanced non-small cell lung cancer patients. FISH is considered the “gold standard” for identification of ALK+ tumors, but its cost-effectiveness and adoption as a screening assay has been debated. Recent reports suggested that ALK IHC may serve as an alternative screening or possibly a diagnostic method. In this context, CALK was initiated to assess the feasibility of implementing ALK IHC and/or FISH assays across Canadian hospitals. Methods: FISH-confirmed 22 ALK+ and 6 ALK- tumors were used as study samples. Unstained sections and scanned images of HE-stained slides from each tumor block were distributed to participating centres. IHC protocols with best signal to noise ratio using the 5A4 (Novocastra) or ALK-1 (Dako) antibodies were developed for various auto-stainers and implemented to suit the existing conditions of the participating centres. A common FISH protocol using the ALK break-apart probe (Abbott Molecular, Chicago, IL) was developed based on published reports. H-score was used to assess IHC. FISH signals were scored in 100 tumor cells/case by 2-3 pre-trained persons. A second round IHC study using newly distributed slides was completed by 8 centres. Results: Independent IHC scores from 12 centres and FISH scores from 11 centres were collected and analysed. The intraclass correlation coefficients (ICC) between centres for IHC and FISH were 0.84 and 0.68, respectively. Following the analysis of initial IHC results, a second round study resulted in improved ICC of 0.94. One of 23 tumors revealed IHC-/FISH+ discrepancy, with the FISH revealing unusual signal configurations that suggested an atypical rearrangement. However, the sensitivity and specificity of FISH results across centres using the 15 aberrant signals cut-off ranged from 86.7-100% and 100%, respectively. Conclusions: Standardization across multiple centres for ALK testing by IHC and FISH can be achieved. IHC detected all FISH+ ALK tumors, except for one discrepant case with atypical FISH finding of unknown clinical implication. The study was supported by a Pfizer Canada grant.

Loss of PTEN expression is associated with increased risk of recurrence after prostatectomy for clinically localized prostate cancer

PTEN (phosphatase and tensin homolog on chromosome 10) is one of the most frequently lost tumor suppressor genes in human cancers and it has been described in more than two-thirds of patients with advanced/aggressive prostate cancer. Previous studies suggest that, in prostate cancer, genomic PTEN loss is associated with tumor progression and poor prognosis. Thus, we evaluated whether immunohistochemical PTEN expression in prostate cancer glands was associated with higher risk of recurrence, using a nested case-control study that included 451 men who recurred and 451 men who did not recur with clinically localized prostate cancer treated by radical prostatectomy. Recurrence was defined as biochemical recurrence (serum prostate-specific antigen >0.2 ng/ml) or clinical recurrence (local recurrence, systemic metastases, or prostate cancer-related death). Cases and controls were matched on pathological T stage, Gleason score, race/ethnicity, and age at surgery. Odds ratios of recurrence and 95% confidence intervals were estimated using conditional logistic regression to account for the matching factors and to adjust for year of surgery, preoperative prostate-specific antigen concentrations, and status of surgical margins. Men who recurred had a higher proportion of PTEN negative expression (16 vs 11%, P=0.05) and PTEN loss (40 vs 31%, P=0.02) than controls. Men with markedly decreased PTEN staining had a higher risk of recurrence (odds ratio=1.67; 95% confidence intervals 1.09, 2.57; P=0.02) when compared with all other men. In summary, in patients with clinically localized prostate cancer treated by prostatectomy, decreased PTEN expression was associated with an increased risk of recurrence, independent of known clinicopathological factors.

Immunoexpression status and prognostic value of mammalian target of rapamycin and hypoxia-induced pathway members in papillary cell renal cell carcinomas

Dysregulation of the mammalian target of rapamycin and hypoxia-induced pathways has been consistently identified in clear cell renal cell carcinomas. However, experience with non-clear cell renal cell carcinoma subtypes is scant. In this study, we evaluated the immunohistochemical expression of upstream (PTEN and phosphorylated AKT) and downstream (phosphorylated S6 and 4EBP1) effectors of the mammalian target of rapamycin pathway, as well as related cell-cycle proteins (p27 and c-MYC), and a member of the hypoxia-induced pathway (HIF-1α) in 54 patients with papillary renal cell carcinoma treated by nephrectomy. PTEN was lower in tumor than in normal kidney, and loss of PTEN expression was found in 48% of the patients. In tumor tissues, phosphorylated S6, 4EBP1, and HIF-1α were higher than in normal kidney. Conversely, scores of p27 were lower in tumor than in normal kidney. Finally, scores of c-MYC and phosphorylated AKT were similar in tumor and in normal kidney. Overall mortality and cancer-specific mortality were 24% and 11%, respectively. Tumor progression was observed in 17% of the patients. None of the tested biomarkers predicted cancer-specific mortality or tumor progression. As expected, patients with high T-stage tumors had higher hazard ratios for cancer-specific mortality (hazard ratio, 6.9) and tumor progression (hazard ratio, 6.7). Patients with higher Fuhrman grades also had higher risks for cancer-specific mortality (hazard ratio, 11.4) and tumor progression (hazard ratio, 4.5). In summary, our study provides evidence of dysregulation of the mammalian target of rapamycin and hypoxia-induced pathways in papillary renal cell carcinoma. Immunohistochemistry for members of the mammalian target of rapamycin pathway and for HIF-1α lacked prognostic significance in our cohort.

Renal cell carcinoma associated with peritumoral sarcoid-like reaction without intratumoral granuloma

Non-necrotizing epithelioid granulomas have been described in association with many primary tumors. In such cases, they are designated as sarcoid-like reaction. Although it is more seen in carcinomas than in sarcomas, it is very rarely reported in renal carcinoma. Here, we describe a rare association of prominent peritumoral sarcoid-like reaction without intratumoral granulomas and conventional clear cell renal carcinoma in a 62-year-old-male, without clinical or laboratory finding of sarcoidosis. At 30 months follow-up, he had no recurrence. Virtual slides: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/4054525336657922.

Improved bioavailability of epoxyeicosatrienoic acids reduces TP-receptor agonist-induced tension in human bronchi

Epoxyeicosatrienoic acid (EET) and thromboxane A2are arachidonic acid derivatives. The former has initially been defined as an epithelium-derived hyperpolarizing factor displaying broncho-relaxing ( 4 ) and anti-inflammatory properties, as recently demonstrated ( 25 ), whereas thromboxane A2induces vaso- and bronchoconstriction upon binding to thromboxane-prostanoid (TP)-receptor. EETs, however, are quickly degraded by the soluble epoxide hydrolase (sEH) into inactive diol compounds ( 25 ). The aim of this study was to investigate the effects of 14,15-EET on TP-receptor activation in human bronchi. Tension measurements performed on native bronchi from various species, acutely treated with increasing 14,15-EET concentrations, revealed specific and concentration-dependent relationships as well as a decrease in the tension induced by 30 nM U-46619, used as a synthetic TP-receptor agonist. Interestingly, acute treatments with 3 μM N-(methylsulfonyl)-2-(2-propynyloxy)-benzenehexanamide, an epoxygenase inhibitor, which minimizes endogenous production of EET, resulted in an increased reactivity to U-46619. Furthermore, we demonstrated that chronic treatments with trans-4-[4-(3-adamantan-1-yl-ureido)-cyclohexyloxy]-benzoic acid (t-AUCB), a sEH inhibitor, reduced human bronchi reactivity to U-46619. During our tension measurements, we also observed that human bronchi generated small-amplitude contractions; these spontaneous activities were reduced upon acute 14,15-EET treatments in the presence of t-AUCB. Altogether, these data demonstrate that endogenous and exogenous 14,15-EET could interfere with the activation of TP-receptors as well as with spontaneous oscillations in human airway smooth muscle tissues.

Increased gene copy number of ERG on chromosome 21 but not TMPRSS2-ERG fusion predicts outcome in prostatic adenocarcinomas

The role of TMPRSS2-ERG gene fusion in prostate cancer prognostication remains controversial. We evaluated the prognostic role of TMPRSS2-ERG fusion using fluorescence in situ hybridization analysis in a case-control study nested in The Johns Hopkins retropubic radical prostatectomy cohort. In all, 10 tissue microarrays containing paired tumors and normal tissues obtained from 172 cases (recurrence) and 172 controls (non-recurrence) matched on pathological grade, stage, race/ethnicity, and age at the time of surgery were analyzed. All radical prostatectomies were performed at our institution between 1993 and 2004. Recurrence was defined as biochemical recurrence, development of clinical evidence of metastasis, or death from prostate carcinoma. Each tissue microarray spot was scored for the presence of TMPRSS2-ERG gene fusion and for ERG gene copy number gains. The odds ratio of recurrence and 95% confidence intervals were estimated from conditional logistic regression. Although the percentage of cases with fusion was slightly lower in cases than in controls (50 vs 57%), the difference was not statistically significant (P=0.20). The presence of fusion due to either deletion or split event was not associated with recurrence. Similarly, the presence of duplicated ERG deletion, duplicated ERG split, or ERG gene copy number gain with a single ERG fusion was not associated with recurrence. ERG gene polysomy without fusion was significantly associated with recurrence (odds ratio 2.0, 95% confidence interval 1.17-3.42). In summary, TMPRSS2-ERG fusion was not prognostic for recurrence after retropubic radical prostatectomy for clinically localized prostate cancer, although men with ERG gene copy number gain without fusion were twice more likely to recur.

NCS 613, a potent and specific PDE4 inhibitor, displays anti-inflammatory effects on human lung tissues

Chronic inflammation is a hallmark of pulmonary diseases, which leads to lung parenchyma destruction (emphysema) and obstructive bronchiolitis occurring in both chronic obstructive pulmonary disease and asthma. Inflammation is strongly correlated with low intracellular cAMP levels and increase in specific cAMP hydrolyzing activity. The aim of the present study was to investigate the role of the cyclic phosphodiesterase type 4 (PDE4) in human lung and to determine the effects of NCS 613, a new PDE4 inhibitor, on lung inflammation and bronchial hyperresponsiveness. High cAMP-PDE activities were found in the cytosoluble fractions from human lung parenchyma and distal bronchi. PDE4 (rolipram sensitive) represented 40% and 56% of total cAMP-PDE activities in the above-corresponding tissues. Moreover, PDE4A, PDE4B, PDE4C, and PDE4D isoforms were detected in all three subcellular fractions (cytosolic, microsomal, and nuclear) with differential distributions according to specific variants. Pharmacological treatments with NCS 613 significantly decreased PDE4 activity and reduced IκBα degradation in cultured parenchyma, both of which are usually correlated with a lower inflammation status. Moreover, NCS 613 pretreatment potentiated isoproterenol-induced relaxations in human distal bronchi, while reducing TNF-α-induced hyperresponsiveness in cultured bronchi, as assessed in the presence of methacholine, U-46619, or histamine. This reducing effect of NCS 613 on human bronchi hyperresponsiveness triggered by TNF-α was related to a lower expression level of PDE4B and PDE4C, as well as a downregulation of the phosphorylated forms of p38-MAPK, CPI-17, and MYPT-1, which are known to control tone. In conclusion, specific PDE4 inhibitors, such as NCS 613, may represent an alternative and isoform-specific approach toward reducing human lung inflammation and airway overreactivity.

Decreased expression of Cyr61 is associated with prostate cancer recurrence after surgical treatment

PURPOSE

Cysteine-rich angiogenic inducer 61 (Cyr61) is an extracellular matrix protein involved in the transduction of growth factor and hormone signaling. Previous studies have suggested that Cyr61 may be a marker for a more aggressive phenotype. In this study, we evaluated the association between Cyr61 staining intensity and subsequent recurrence after surgical treatment of clinically localized prostate cancer.

EXPERIMENTAL DESIGN

A study of 229 men with recurrence and 229 controls matched on age, race, pathologic stage, and Gleason sum nested in a cohort of men who underwent radical prostatectomy for clinically localized prostate cancer, utilizing immunohistochemistry analysis of tissue microarray (TMA) sections, was conducted. Odds ratios (OR) of recurrence and 95% confidence intervals (CIs) were estimated using conditional logistic regression.

RESULTS

Recurrence was identified in 12.2% of cases, and in 24.0% of controls that had at least 1 TMA spot containing cancer with a staining intensity of 3 (P = 0.001). Taking into account age, pathologic stage and grade, presurgery prostate-specific antigen concentration, and calendar of surgery as a measure of tissue block storage time, men with a Cyr61 staining intensity of 3 were 56% less likely to recur than men with a lower staining intensity (OR = 0.44, 95% CI = 0.22-0.90).

CONCLUSIONS

High Cyr61 staining intensity in adenocarcinoma was associated with a lower risk of recurrence after surgical treatment of prostate cancer independent of pathologic tumor characteristics. If validated in other sample sets, Cyr61 may serve as a tissue biomarker for stratifying men for risk of recurrence and thus could inform treatment decision making.

Expression status and prognostic significance of mammalian target of rapamycin pathway members in urothelial carcinoma of urinary bladder after cystectomy

BACKGROUND

Bladder urothelial carcinoma has high rates of mortality and morbidity. Identifying novel molecular prognostic factors and targets of therapy is crucial. Mammalian target of rapamycin (mTOR) pathway plays a pivotal role in establishing cell shape, migration, and proliferation.

METHODS

Tissue microarrays were constructed from 132 cystectomies (1994-2002). Immunohistochemistry was performed for Pten, c-myc, p27, phosphorylated (phos)Akt, phosS6, and 4E-BP1. Markers were evaluated for pattern, percentage, and intensity of staining.

RESULTS

Mean length of follow-up was 62.6 months (range, 1-182 months). Disease progression, overall survival (OS), and disease-specific survival (DSS) rates were 42%, 60%, and 68%, respectively. Pten showed loss of expression in 35% of bladder urothelial carcinoma. All markers showed lower expression in invasive bladder urothelial carcinoma compared with benign urothelium with the exception of 4E-BP1. Pten, p27, phosAkt, phosS6, and 4E-BP1 expression correlated with pathologic stage (pathological stage; P<.03). Pten, 4E-BP1, and phosAkt expression correlated with divergent aggressive histology and invasion. phosS6 expression inversely predicted OS (P=.01), DSS (P=.001), and progression (P=.05). c-myc expression inversely predicted progression (P=.01). In a multivariate analysis model that included TNM stage grouping, divergent aggressive histology, concomitant carcinoma in situ, phosS6, and c-myc expression, phosS6 was an independent predictor of DSS (P=.03; hazard ratio [HR], -0.19), whereas c-myc was an independent predictor of progression (P=.02; HR, -0.38). In a second model substituting organ-confined disease and lymph node status for TNM stage grouping, phosS6 and c-myc remained independent predictors of DSS (P=.03; HR, -0.21) and progression (P=.03; HR, -0.34), respectively.

CONCLUSIONS

We found an overall down-regulation of mTOR pathway in bladder urothelial carcinoma. phosS6 independently predicted DSS, and c-myc independently predicted progression.

Androgen-induced TOP2B-mediated double-strand breaks and prostate cancer gene rearrangements

DNA double strand breaks (DSB) can lead to development of genomic rearrangements, which are hallmarks of cancer. TMPRSS2-ERG gene fusions in prostate cancer (PCa) are among the most common genomic rearrangements observed in human cancer. We show that androgen signaling promotes co-recruitment of androgen receptor (AR) and topoisomerase II beta (TOP2B) to sites of TMPRSS2-ERG genomic breakpoints, triggering recombinogenic TOP2B-mediated DSB. Furthermore, androgen stimulation resulted in de novo production of TMPRSS2-ERG fusion transcripts in a process requiring TOP2B and components of DSB repair machinery. Finally, unlike normal prostate epithelium, prostatic intraepithelial neoplasia (PIN) cells showed strong co-expression of AR and TOP2B. These findings implicate androgen-induced TOP2B-mediated DSB in generating TMPRSS2-ERG rearrangements.

A pharmacodynamic study of rapamycin in men with intermediate- to high-risk localized prostate cancer

PURPOSE

Given discrepancies between preclinical and clinical observations of mammalian target of rapamycin (mTOR) inhibition in prostate cancer, we sought to determine the pharmacodynamic effects of the mTOR/TORC1 inhibitor rapamycin in men with intermediate- to high-risk prostate cancer undergoing radical prostatectomy.

EXPERIMENTAL DESIGN

Rapamycin was given at 3 or 6 mg orally for 14 days before radical prostatectomy in men with multifocal Gleason sum > or =7 prostate cancer; 10 untreated control subjects were included. The primary outcome was inhibition of phosphorylation of ribosomal S6 in posttreatment radical prostatectomy versus pretreatment biopsy tumor tissue, evaluated using a Simon two-stage design for pharmacodynamic efficacy.

RESULTS

Thirty-two subjects were accrued: 20 at 3 mg, 2 at 6 mg, and 10 controls. No dose-limiting toxicities were observed at 3 mg; however, two of two men enrolled at 6 mg experienced dose-limiting toxicities including thrombocytopenia and fever with grade 3 stomatitis. Adverse events observed at 3 mg included stomatitis, rash, ileus, and neutropenia. Pharmacodynamic studies showed tumor S6 phosphorylation inhibition in 50% of 10 evaluable rapamycin-treated men with sufficient paired tissue [median 58% inhibition (P = 0.049) versus 2% inhibition in controls (P = 0.75)] with no significant effect on AKT activity. We observed no change in Ki-67 or caspase-3 cleavage but noted a reduction in cytoplasmic p27 staining with increased nuclear localization with rapamycin treatment. Prostate tissue rapamycin concentrations were 3- to 4-fold higher than blood.

CONCLUSIONS

At 3 mg daily, rapamycin successfully and safely inhibited prostate cancer S6 phosphorylation and achieved relatively high prostate tissue concentrations. No effect on AKT phosphorylation, tumor proliferation, or apoptosis was observed.

Extracellular matrix associated protein CYR61 is linked to prostate cancer development

PURPOSE

The cancer cell microenvironment includes complex interactions between the cell and the extracellular matrix. Expression of the CCN family of extracellular matrix associated proteins is often modified in disease states. Depending on cancer type these changes are linked with enhanced or inhibited tumor growth. We characterized Cyr61 in prostate cancer. Cyr61 is an integrin binding matricellular protein with altered expression in many cancer types.

MATERIALS AND METHODS

Cyr61 expression in prostate cancer, benign prostatic hyperplasia and normal tissues was evaluated by microarray analysis, quantitative real-time polymerase chain reaction and tissue microarray. Immunoblots were analyzed to assess endogenous protein expression in prostate cancer cell lines.

RESULTS

On genomic analysis Cyr61 up-regulation was observed in prostate cancer tissue and in normal prostate tissue adjacent to tumor vs that in prostate donor tissue. In 174 matched tumors and normal prostate tissues adjacent to tumor tissue microarray revealed significantly up-regulated Cyr61 protein expression in cancer tissue vs normal prostate tissue adjacent to tumor. Also, increased Cyr61 expression correlated with Gleason sum 8 or greater cancer. Staining in high grade prostatic intraepithelial neoplasia was moderately up-regulated vs that in normal prostate tissue adjacent to tumor but generally less intense than in carcinoma tissue.

CONCLUSIONS

In addition to the correlation with more advanced disease, the strong association between Cyr61 expression and prostate cancer supports the potential usefulness of Cyr61 as a novel biomarker for prostate cancer. This warrants further analysis to determine the mechanisms by which Cyr61 may contribute to prostate cancer development and progression.

Topoisomerase II alpha status in renal medullary carcinoma: immuno-expression and gene copy alterations of a potential target of therapy

PURPOSE

Renal medullary carcinoma is an aggressive renal neoplasm without currently available effective therapy to our knowledge. Topoisomerase II alpha is a gyrase involved in cell proliferation, and DNA maintenance and repair. Topoisomerase II alpha is a target of inhibiting agents such as anthracyclines. Triggered by a recent response to topoisomerase II alpha inhibitors in a patient with renal medullary carcinoma, we evaluated topoisomerase II alpha expression in relation to the proliferation index and topoisomerase II alpha gene copy number status in a larger series of patients with renal medullary carcinoma.

MATERIALS AND METHODS

Archival tissues from 14 renal medullary carcinomas were retrieved from our 3 institutions. Immunohistochemistry was performed using monoclonal antibodies for topoisomerase II alpha and Ki67. The percent of cells with positive nuclear staining was assessed in the highest area of expression for each marker. A previously suggested greater than 5% cutoff was used for topoisomerase II alpha over expression. The topoisomerase II alpha gene copy number was evaluated using fluorescence in situ hybridization. Locus specific topoisomerase II alpha gene and chromosome 17 centromere probes were used. The total number of topoisomerase II alpha and chromosome 17 centromere signals was counted in 150 cells per tumor and a topoisomerase II alpha-to-chromosome 17 centromere signal ratio was calculated in each tumor. A topoisomerase II alpha-to-chromosome 17 centromere ratio of 2.0 or greater and less than 0.8 was used as a cutoff for amplification and deletion, respectively. The percent of tumor cells with polysomic, eusomic or monosomic chromosome 17 status was also determined.

RESULTS

On immuno-expression analysis topoisomerase II alpha immunohistochemistry was technically inconclusive in 1 renal medullary carcinoma. Topoisomerase II alpha was over expressed in 11 of 13 renal medullary carcinomas (85%) (median 50%, range 1% to 80%). As expected, a high Ki67 proliferation index was noted in 13 of 14 tumors (median 87.5%, range 2% to 100%). Ki67 expression was greater than topoisomerase II alpha expression in all 13 informative tumors. A strong, statistically significant correlation was found for topoisomerase II alpha and Ki67 expression (pairwise CC 0.9, p = 0.0000). Topoisomerase II alpha over expression was associated with shorter survival (p = 0.000). On fluorescence in situ hybridization no topoisomerase II alpha amplification was detected in any of the 14 renal medullary carcinomas, including the 11 with topoisomerase II alpha over expression. Topoisomerase II alpha gene deletions were noted in 4 tumors. Two of 4 deletions were associated with chromosome 17 monosomy and 2 were in eusomic chromosome 17 tumors.

CONCLUSIONS

Topoisomerase II alpha is over expressed in 85% of renal medullary carcinomas, potentially supporting the use of topoisomerase II alpha inhibitor agents to treat this aggressive renal tumor. Our findings suggest that topoisomerase II alpha over expression in our renal medullary carcinoma cohort was not due to gene amplification, but rather to transcriptional or post-transcriptional modifications. The significance of the incidentally found topoisomerase II alpha deletions in 28% of renal medullary carcinomas requires further evaluation.

TMPRSS2-ERG gene fusions are infrequent in prostatic ductal adenocarcinomas

Ductal adenocarcinoma of the prostate is an unusual subtype that may be associated with a more aggressive clinical course, and is less responsive to conventional therapies than the more common prostatic acinar adenocarcinoma. However, given its frequent association with an acinar component at prostatectomy, some have challenged the concept of prostatic ductal adenocarcinoma as a distinct clinicopathologic entity. We studied the occurrence of the TMPRSS2-ERG gene fusion, in 40 surgically resected ductal adenocarcinoma cases, and in their associated acinar component using fluorescence in situ hybridization. A group of 38 'pure' acinar adenocarcinoma cases matched with the ductal adenocarcinoma group for pathological grade and stage was studied as a control. Compared with the matched acinar adenocarcinoma cases, the TMPRSS2-ERG gene fusion was significantly less frequently observed in ductal adenocarcinoma (45 vs 11% of cases, P=0.002, Fisher's exact test). Here, of the ductal adenocarcinoma cases with the gene fusion, 75% were fused through deletion, and the remaining case was fused through translocation. The TMPRSS2-ERG gene fusion was also rare in the acinar component of mixed ductal-acinar tumors when compared with the pure acinar adenocarcinoma controls (5 vs 45%, P=0.001, Fisher's exact test). In 95% of the ductal adenocarcinoma cases in which a concurrent acinar component was analyzed, there was concordance for presence/absence of the TMPRSS2-ERG gene fusion between the different histologic subtypes. In the control group of pure acinar adenocarcinoma cases, 59% were fused through deletion and 41% were fused through translocation. The presence of the TMPRSS2-ERG gene fusion in some cases of prostatic ductal adenocarcinoma supports the concept that ductal adenocarcinoma and acinar adenocarcinoma may be related genetically. However, the significantly lower rate of the gene fusion in pure ductal adenocarcinoma cases underscores the fact that genetic and biologic differences exist between these two tumors that may be important for future therapeutic strategies.

Global DNA hypomethylation in intratubular germ cell neoplasia and seminoma, but not in nonseminomatous male germ cell tumors

Alterations in methylation of CpG dinucleotides at the 5 position of deoxycytidine residues (5(m)C) are a hallmark of cancer cells, including testicular germ cell tumors. Virtually all testicular germ cell tumors are believed to be derived from intratubular germ cell neoplasia unclassified (IGCNU), which is thought to arise from primordial germ cells. Prior studies revealed that seminomas contain reduced levels of global DNA methylation as compared with nonseminomatous germ cell tumors. Smiraglia et al have proposed a model whereby seminomas arise from IGCNU cells derived from primordial germ cells that have undergone 5(m)C erasure, and nonseminomas arise from IGCNU cells derived from primordial germ cells that have already undergone de novo methylation after the original erasure of methylation and contain normal 5(m)C levels. Yet the methylation status of IGCNU has not been determined previously. We used immunohistochemical staining against 5(m)C to evaluate global methylation in IGCNU and associated invasive testicular germ cell tumors. Strikingly, staining for 5(m)C was undetectable (or markedly reduced) in the majority of IGCNU and seminomas, yet there was robust staining in nonseminomatous germ cell tumors. The lack of staining for 5(m)C in IGCNU and seminomas was also found in mixed germ cell tumors containing both seminomatous and nonseminomatous components. Lack of 5(m)C staining was not related to a lack of the maintenance methyltransferase (DNA methyltransferase 1) protein. We conclude that testicular germ cell tumors are derived in most cases from IGCNU cells that have undergone developmentally programmed 5(m)C erasure and that the degree of subsequent de novo methylation is most closely related to the differentiation state of the neoplastic cells. That is, IGCNU cells and seminoma cells remain unmethylated, whereas all other histological types appear to arise after de novo methylation.