Eddie Fridman

MicroRNAs accurately identify cancer tissue origin

MicroRNAs (miRNAs) belong to a class of noncoding, regulatory RNAs that is involved in oncogenesis and shows remarkable tissue specificity. Their potential for tumor classification suggests they may be used in identifying the tissue in which cancers of unknown primary origin arose, a major clinical problem. We measured miRNA expression levels in 400 paraffin-embedded and fresh-frozen samples from 22 different tumor tissues and metastases. We used miRNA microarray data of 253 samples to construct a transparent classifier based on 48 miRNAs. Two-thirds of samples were classified with high confidence, with accuracy >90%. In an independent blinded test-set of 83 samples, overall high-confidence accuracy reached 89%. Classification accuracy reached 100% for most tissue classes, including 131 metastatic samples. We further validated the utility of the miRNA biomarkers by quantitative RT-PCR using 65 additional blinded test samples. Our findings demonstrate the effectiveness of miRNAs as biomarkers for tracing the tissue of origin of cancers of unknown primary origin.

Uterine leiomyosarcoma: does the primary surgical procedure matter?

Background: Uterine leiomyosarcoma (LMS) has a poor prognosis even after early-stage diagnosis. Because there are no accurate diagnostic tools for preoperatively distinguishing LMS from uterine leiomyoma, surgeons might opt for partial surgical procedures such as myomectomy or subtotal hysterectomy. We sought to determine whether a surgical procedure that cuts through the tumor influences prognosis. Materials and Methods: Demographic and clinical data of consecutive patients with stage I LMS treated between 1969 and 2005 were reviewed. The study population was divided into group A: patients whose first surgical intervention was total hysterectomy (n = 21); and group B: patients who underwent procedures involving tumor injury, for example, myomectomy, laparoscopic hysterectomy with a morcellator knife, or hysteroscopic myomectomy (n = 16). Survival rates were analyzed and compared. A Cox proportional hazards model was used to assess the association between variables of interest and prognosis. Results: The median age at diagnosis was 50 years (range, 30-74 years). Median follow-up duration was 44 months. The 2 groups did not differ significantly in age at diagnosis, menopausal status, gravidity, parity, postoperative radiotherapy, or time to last follow-up. Kaplan-Meier curves showed significantly better survival rates (P = 0.04) and a significant advantage in recurrence rate (P = 0.03) for group A compared with group B. Survival in group A was 2.8-fold better than that in group B (95% confidence interval, 1.02-7.67). These estimates remained stable after adjustment for age, menopausal status, and radiotherapy. Conclusions: In patients with stage I LMS, primary surgery involving tumor injury seems to be associated with a worse prognosis than total hysterectomy as a primary intervention.

Accurate Molecular Classification of Renal Tumors Using MicroRNA Expression

Subtypes of renal tumors have different genetic backgrounds, prognoses, and responses to surgical and medical treatment, and their differential diagnosis is a frequent challenge for pathologists. New biomarkers can help improve the diagnosis and hence the management of renal cancer patients. We extracted RNA from 71 formalin-fixed paraffin-embedded (FFPE) renal tumor samples and measured expression of more than 900 microRNAs using custom microarrays. Clustering revealed similarity in microRNA expression between oncocytoma and chromophobe subtypes as well as between conventional (clear-cell) and papillary tumors. By basing a classification algorithm on this structure, we followed inherent biological correlations and could achieve accurate classification using few microRNAs markers. We defined a two-step decision-tree classifier that uses expression levels of six microRNAs: the first step uses expression levels of hsa-miR-210 and hsa-miR-221 to distinguish between the two pairs of subtypes; the second step uses either hsa-miR-200c with hsa-miR-139-5p to identify oncocytoma from chromophobe, or hsa-miR-31 with hsa-miR-126 to identify conventional from papillary tumors. The classifier was tested on an independent set of FFPE tumor samples from 54 additional patients, and identified correctly 93% of the cases. Validation on qRT-PCR platform demonstrated high correlation with microarray results and accurate classification. MicroRNA expression profiling is a very effective molecular bioassay for classification of renal tumors and can offer a quantitative standardized complement to current methods of tumor classification.

AKT1 pleckstrin homology domain E17K activating mutation in endometrial carcinoma.

OBJECTIVES The PI3K/AKT pathway is frequently activated in endometrial carcinoma (EC) mainly due to mutations in the PIK3CA and PTEN genes. These events are common and believed to be the key to endometrial carcinogenesis. Recently, a somatic activating mutation in the AKT1 gene (E17K) was identified in several cancer types. In this study we explored the frequency of this AKT1 mutation in endometrial carcinoma. METHODS Tumor DNA, extracted from 73 EC was analyzed for AKT1 E17K mutation (G49A) using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). In addition, the tumors were screened for coexisting common mutations in PTEN, PIK3CA and KRAS. RESULTS The AKT1 E17K mutation was detected in 4% of EC. One of the AKT1-mutated tumors showed coexisting PTEN loss-of-function mutation. CONCLUSION We identified the AKT1 E17K mutation in 4% of endometrial carcinomas. The presence of double AKT1/ PTEN mutants is in accord with the hypothesis that in EC more than one hit is required to completely activate the PI3K pathway. Furthermore, AKT1 mutations were limited to high grade, advanced stage tumors suggesting that this mutation confers a more aggressive tumor behavior.

Promising effect of aromatase inhibitors on recurrent granulosa cell tumors.

Recurring adult-type granulosa cell tumors of the ovary are usually treated by surgical resection followed by chemotherapy or radiation. However, the results of such treatment are disappointing. We describe 4 patients in whom recurrent ovarian granulosa cell tumors were treated with an aromatase inhibitor, with promising results.

Classic neurothekeoma (nerve sheath myxoma) and cellular neurothekeoma of the oral mucosa: immunohistochemical profiles

BACKGROUND Classic neurothekeoma (nerve sheath myxoma) is regarded as being a true benign cutaneous tumor of nerve sheath origin. Cellular neurothekeoma was separated from the classic type by histogenesis, morphology and immunophenotype. Whether cellular neurothekeoma represents a continuum within the spectrum of classic neurothekeoma or is an independent entity is controversial. Only a small number of classic neurothekeomas of the oral mucosa have been reported and there are even fewer publications on cellular neurothekeoma. We analyzed a series of oral neurothekeomas (classic and cellular) with a panel of neural and other mesenchymal markers to enhance their diagnosis and classification. METHODS One cellular and three classic neurothekeomas were submitted to a panel of immunohistochemical stains with antibodies against S100, S100A6, NSE, NKI/C3, PGP9.5, α-SMA, HHF-35, CD68 and vimentin. Two cases of neurofibroma (plexiform type), representing a true lesion of neural origin, served as control. RESULTS The cellular neurothekeoma yielded a positive immunoreaction for S100A6 and NKI/C3 and a negative immunoreaction for S-100. The classic neurothekeomas demonstrated a positive reaction for S-100 and S100A6, but a negative one for NKI/C3. Other markers were non-contributory to distinguishing between these types of lesions. CONCLUSIONS The small number of reported oral neurothekeomas (classic and cellular) could be due, in part, to the lack of recognition of their particular morphologic and immunohistochemical features. Our results indicate that testing for NKI/C3 immunoreactivity may be of value in distinguishing between cellular and classic neurothekeoma.

Development and validation of a microRNA-based diagnostic assay for classification of renal cell carcinomas.

Renal cancers account for more than 3% of adult malignancies and cause more than 13,000 deaths per year in the US alone. The four most common types of kidney tumors include the malignant renal cell carcinomas; clear cell, papillary, chromophobe and the benign oncocytoma. These histological subtypes vary in their clinical course and prognosis, and different clinical strategies have been developed for their management. In some kidney tumor cases it can be very difficult for the pathologist to distinguish between tumor types on the basis of morphology and immunohistochemistry (IHC). In this publication we present the development and validation of a microRNA‐based assay for classifying primary kidney tumors. The assay, which classifies the four main kidney tumor types, was developed based on the expression of a set of 24 microRNAs. A validation set of 201 independent samples was classified using the assay and analyzed blindly. The assay produced results for 92% of the samples with an accuracy of 95%.

Villoglandular papillary adenocarcinoma of the uterine cervix: A diagnostic challenge

Villoglandular papillary adenocarcinoma (VGA) is a rare subtype of cervical adenocarcinoma. It tends to appear in younger women and its indolent behavior permits fertility‐preserving treatments. Pathologically, VGA presents a diagnostic challenge. The aim of our study was to evaluate the reliability of histological assessment for pre‐treatment diagnosis of VGA. The data from the outpatient files of 12 patients in whom VGA had been diagnosed were reviewed. Median age at diagnosis was 38.8 years (range 27–65). Final pathology results confirmed VGA in nine patients. Of these, only two had been correctly diagnosed preoperatively, while in three, the initial biopsies were benign or pre‐malignant. In four patients, the biopsy results had been interpreted as an invasive malignant tumor necessitating hysterectomy. The final histological report on the remaining three patients was invasive cervical adenocarcinoma. We conclude that pre‐treatment diagnosis should not be based solely on a simple punch biopsy because of its low rate of diagnostic accuracy.

The relative contribution of urine extravasation to elevate plasma creatinine levels in acute unilateral ureteral obstruction.

INTRODUCTION Rising levels of plasma creatinine in the setting of acute unilateral ureteral obstruction (AUUO) often reflects acute renal failure, mandating kidney drainage. We hypothesize that re-absorption of peri-renal urine extravasation (PUE), a common result of UUO, contributes significantly to the elevation in plasma creatinine, rendering the latter an inaccurate benchmark for renal function. We explored this hypothesis in a rat model of AUUO and PUE. METHODS In total, 20 rats were equally divided into 4 groups. Groups 1 and 2 underwent unilateral ligation of the ureter with infiltration of rats urine (index group) or saline (control) into the peri-renal space. Two additional control groups underwent peri-renal injection of either urine or saline without AUUO. Plasma creatinine levels were determined immediately prior to the procedure (T0), and hourly for 3 hours (T1, T2 and T3). Renal histology was investigated after 3 hours. RESULTS Rats in the index group had a significantly greater increase in plasma creatinine levels over 3 hours compared to all other groups (p < 0.05). At T3, average plasma creatinine levels for the index group increased by 96% (0.49 ± 0.18 mg/dL) compared to 46% (0.23 ± 0.06 mg/dL increase) in the AUUO and saline group, and less than 15% rise in both the non-obstructed control groups. Our study limitations includes lack of spontaneous PUE and intraperitoneal surgical approach. CONCLUSIONS Absorption of peri-renal urine in the presence of AUUO is a significant contributor to rising plasma creatinine levels, beyond those attributable to the obstruction alone, and may overestimate the extent of the true renal functional impairment.

Oncologic Outcomes of Partial Nephrectomy for Stage T3a Renal Cell Cancer

&NA; We present our long‐term multicenter experience with partial nephrectomy for locally advanced tumors (stage pT3a) and compare the oncologic outcomes with those of similar patients treated with radical nephrectomy. The cohort size was 134 patients. Surgery type was not a predictor of the oncologic outcomes at the 5‐year follow‐up point. Our findings suggest that partial nephrectomy can be considered for T3a tumors and, thus, avoid the long‐term complications of radical nephrectomy. Future studies are needed for validation. Background: Partial nephrectomy (PN) for clinical stage T3 tumors is controversial. Radical nephrectomy (RN) has been associated with a greater rate of chronic kidney disease, an increased risk of cardiovascular disease, and increased mortality compared with PN. We present our long‐term 2‐center experience with PN for stage pT3a tumors and compare the oncologic outcomes with those of similar patients treated with RN. Materials and Methods: We reviewed the data from all patients who had undergone nephrectomy for renal cell carcinoma from 1987 to 2015 in 2 medical centers. The study included 134 patients with pathologic stage T3a tumors, of whom 48 and 86 underwent PN and RN, respectively. We compared the 2 groups (PN and RN) using univariate and multivariate analyses. Results: The tumors of all patients with pathologic stage T3a who had undergone PN had been pathologically upstaged from clinical stage T1 or T2. Univariate and multivariate analyses revealed tumor size was significantly different statistically between the study groups (median, 7.0 cm in RN group vs. 4.0 cm in PN group; P < .001). Surgery type was not a predictor of local recurrence (P = .978), metastatic progression (P = .972), death from renal cancer (P = .626), or death from all causes (P = .974) at the 5‐year follow‐up point. Conclusion: The results of the present study have shown similar oncologic outcomes between 48 patients with stage pT3a renal cancer who underwent PN and 86 patients who underwent RN. Although PN was not performed on clinical T3a tumors, our findings suggest that PN can also be considered for these tumors and, thus, avoid the long‐term complications of RN. However, strict follow‐up protocols are mandatory.