Predictors of Long-Term Survival in Patients Treated for Oligometastases

PURPOSE/OBJECTIVE(S)

The purpose of this work is to report the long-term outcomes of patients with oligometastases treated with curative intent radiotherapy in the context of the recently developed ESTRO EORTC classification schema.

MATERIALS/METHODS

This retrospective, single institution study consists of consecutive adult patients with oligometastases from solid tumor malignancy referred to a single high volume radiation oncologist. Oligometastases were defined as 5 or fewer extracranial or intracranial metastatic lesions where all sites of active disease are amenable to treatment. Patients with a history of distant metastases requiring treatment of the primary tumor ± regional lymph nodes were included. Radical local therapies utilized included stereotactic radiotherapy (53% of patients, median dose 27 Gy in 3 fractions), intensity modulated radiotherapy (64% of patients; median dose 50 Gy in 15 fractions), surgery and/or ablation. Overall survival and progression-free survival were estimated using the Kaplan-Meier method. Predictors of survival were assessed using log-rank test for categorical variables and Cox regression for continuous variables for univariable analysis and Cox multivariable analyses.

RESULTS

The study population consists of 130 patients with 207 treated distant metastases referred to radiation oncology between 1/2014 and 12/2021. Key patient characteristics include median age 71, median pre-radiation albumin 3.7 g/dl, 72% ECOG 0-1 performance status, 35% lung primary, 12% prostate primary, median of 1 distant metastasis treated, 31% bone metastases, 30% brain metastases, 47% required treatment to primary tumor ± regional lymph nodes and 71% received systemic therapy after radiation. The most frequent ESTRO EORTC oligometastatic groups were synchronous oligometastases (40%) and metachronous oligorecurrence (29%). At a median follow-up of 28.8 months (IQR 16.0 to 56.3 months), the median overall survival is 37.9 months with a 4-year overall survival of 41.1%. The median progression-free survival was 12.3 months with a 4-year progression-free survival of 22.6%. On multivariable analysis, the strongest predictors of overall survival are age (HR 1.05 [1.02-1.08]; CI: 95%; p<0.001), ECOG performance status (HR 1.69 [1.15-2.47]; CI: 95%; p = 0.007), primary prostate, breast or kidney tumor (HR 2.79 [1.29-6.03]; CI: 95%; p = 0.009) and pre-radiation serum albumin (HR 0.55 [0.35-0.87]; CI: 95%; p = 0.01). The strongest predictors of progression free survival on multivariable analysis are albumin (HR 0.59 [0.39-0.88]; CI: 95%; p = 0.009) and primary prostate, breast or kidney tumor (HR 1.90 [1.06-3.38]; CI: 95%; p = 0.03).

CONCLUSION

Long-term overall survival is not uncommon after radical treatment for oligometastases. The ESTRO EORTC classification provides an enriched nomenclature for oligometastases but is not independently predictive of survival.

Immune profiling of lupus miliaris disseminatus faciei and successful management with anti-tumour necrosis factor therapy

Lupus miliaris disseminatus faciei (LMDF) is a chronic inflammatory dermatosis of unknown aetiology, most often seen in young adults. Although many treatments for LMDF exist, treatment guidelines have not been developed, and response to therapy is generally unpredictable. We present the results of transcriptomic analysis of LMDF lesional skin, which revealed a variety of differentially expressed genes linking LMDF to alterations in innate and adaptive T helper 1 immunity. Immunohistochemical analysis was also performed, identifying similar changes in T-cell immune responses. Given evidence for increased tumour necrosis factor (TNF) pathway activity, our patient, who had previously been refractory to multiple treatments, was initiated on TNF inhibitor therapy with excellent response. This characterization of the LMDF immune response may lead to improved treatment of this condition.

Historical epidemiology of hepatitis C virus in select countries-volume 4

Due to the introduction of newer, more efficacious treatment options, there is a pressing need for policy makers and public health officials to develop or adapt national hepatitis C virus (HCV) control strategies to the changing epidemiological landscape. To do so, detailed, country-specific data are needed to characterize the burden of chronic HCV infection. In this study of 17 countries, a literature review of published and unpublished data on HCV prevalence, viraemia, genotype, age and gender distribution, liver transplants and diagnosis and treatment rates was conducted, and inputs were validated by expert consensus in each country. Viraemic prevalence in this study ranged from 0.2% in Hong Kong to 2.4% in Taiwan, while the largest viraemic populations were in Nigeria (2 597 000 cases) and Taiwan (569 000 cases). Diagnosis, treatment and liver transplant rates varied widely across the countries included in this analysis, as did the availability of reliable data. Addressing data gaps will be critical for the development of future strategies to manage and minimize the disease burden of hepatitis C.

The present and future disease burden of hepatitis C virus infections with today's treatment paradigm: Volume 4

Factors influencing the morbidity and mortality associated with viremic hepatitis C virus (HCV) infection change over time and place, making it difficult to compare reported estimates. Models were developed for 17 countries (Bahrain, Bulgaria, Cameroon, Colombia, Croatia, Dominican Republic, Ethiopia, Ghana, Hong Kong, Jordan, Kazakhstan, Malaysia, Morocco, Nigeria, Qatar and Taiwan) to quantify and characterize the viremic population as well as forecast the changes in the infected population and the corresponding disease burden from 2015 to 2030. Model inputs were agreed upon through expert consensus, and a standardized methodology was followed to allow for comparison across countries. The viremic prevalence is expected to remain constant or decline in all but four countries (Ethiopia, Ghana, Jordan and Oman); however, HCV-related morbidity and mortality will increase in all countries except Qatar and Taiwan. In Qatar, the high-treatment rate will contribute to a reduction in total cases and HCV-related morbidity by 2030. In the remaining countries, however, the current treatment paradigm will be insufficient to achieve large reductions in HCV-related morbidity and mortality.

Strategies to manage hepatitis C virus infection disease burden-Volume 4

The hepatitis C virus (HCV) epidemic was forecasted through 2030 for 17 countries in Africa, Asia, Europe, Latin America and the Middle East, and interventions for achieving the Global Health Sector Strategy on viral hepatitis targets-"WHO Targets" (65% reduction in HCV-related deaths, 90% reduction in new infections and 90% of infections diagnosed by 2030) were considered. Scaling up treatment and diagnosis rates over time would be required to achieve these targets in all but one country, even with the introduction of high SVR therapies. The scenarios developed to achieve the WHO Targets in all countries studied assumed the implementation of national policies to prevent new infections and to diagnose current infections through screening.

Asian-Pacific clinical practice guidelines on the management of hepatitis B: a 2015 update

Worldwide, some 240 million people have chronic hepatitis B virus (HBV), with the highest rates of infection in Africa and Asia. Our understanding of the natural history of HBV infection and the potential for therapy of the resultant disease is continuously improving. New data have become available since the previous APASL guidelines for management of HBV infection were published in 2012. The objective of this manuscript is to update the recommendations for the optimal management of chronic HBV infection. The 2015 guidelines were developed by a panel of Asian experts chosen by the APASL. The clinical practice guidelines are based on evidence from existing publications or, if evidence was unavailable, on the experts' personal experience and opinion after deliberations. Manuscripts and abstracts of important meetings published through January 2015 have been evaluated. This guideline covers the full spectrum of care of patients infected with hepatitis B, including new terminology, natural history, screening, vaccination, counseling, diagnosis, assessment of the stage of liver disease, the indications, timing, choice and duration of single or combination of antiviral drugs, screening for HCC, management in special situations like childhood, pregnancy, coinfections, renal impairment and pre- and post-liver transplant, and policy guidelines. However, areas of uncertainty still exist, and clinicians, patients, and public health authorities must therefore continue to make choices on the basis of the evolving evidence. The final clinical practice guidelines and recommendations are presented here, along with the relevant background information.

Whole-genome sequencing of two North American Drosophila melanogaster populations reveals genetic differentiation and positive selection

The prevailing demographic model for Drosophila melanogaster suggests that the colonization of North America occurred very recently from a subset of European flies that rapidly expanded across the continent. This model implies a sudden population growth and range expansion consistent with very low or no population subdivision. As flies adapt to new environments, local adaptation events may be expected. To describe demographic and selective events during North American colonization, we have generated a data set of 35 individual whole-genome sequences from inbred lines of D. melanogaster from a west coast US population (Winters, California, USA) and compared them with a public genome data set from Raleigh (Raleigh, North Carolina, USA). We analysed nuclear and mitochondrial genomes and described levels of variation and divergence within and between these two North American D. melanogaster populations. Both populations exhibit negative values of Tajima's D across the genome, a common signature of demographic expansion. We also detected a low but significant level of genome-wide differentiation between the two populations, as well as multiple allele surfing events, which can be the result of gene drift in local subpopulations on the edge of an expansion wave. In contrast to this genome-wide pattern, we uncovered a 50-kilobase segment in chromosome arm 3L that showed all the hallmarks of a soft selective sweep in both populations. A comparison of allele frequencies within this divergent region among six populations from three continents allowed us to cluster these populations in two differentiated groups, providing evidence for the action of natural selection on a global scale.

Phase I/II trial of concurrent sunitinib (SU) and image-guided radiotherapy (IGRT) followed by maintenance systemic therapy for patients with oligometastases

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Background: Preclinical data suggest that SU enhances the efficacy of radiotherapy. We tested the combination of SU and hypofractionated IGRT in a cohort of patients with historically incurable distant metastases.

Methods: Eligible patients had 1 to 5 sites of metastatic solid tumors measuring ≤ 6 cm. The most common tumor types treated were head and neck, liver, lung, kidney, and prostate cancers. Patients were treated with concurrent SU (25 to 50 qd d 1–28) and IGRT (40 to 50 Gy in 10 fractions d 8–19). Following IGRT, patients could either receive maintenance SU (50 mg daily, 4 weeks on/2 weeks off starting on d 43) or alternate forms of systemic therapy. Most patients were treated with the recommended phase II dose of SU 37.5 mg and IGRT 50 Gy. Maintenance SU was used in 40% of patients.

Results: Between 2/07 and 6/08, 43 patients with 81 metastatic lesions were enrolled with a median follow up for surviving patients was 20.1 months (range, 5–37 months). The incidence of acute grade ≥ 3 toxicities was 33%, most commonly myelosuppression, bleeding and abnormal liver function tests. The 2-year estimates for local control and distant control were 74% and 43%, respectively. The 2-year estimates for progression- free survival and overall survival were 39% and 46%, respectively. To date, 15 (35%) patients were alive without evidence of disease, 6 (14%) were alive with distant metastases, 13 (30%) were dead from distant metastases, 1 (2%) was dead from local progression, 6 (14%) were dead from comorbid illness, and 2 (5%) were dead from treatment-related toxicities. Predictors of improved progression-free survival were genitourinary primary tumor (HR 0.18; p=0.04), IGRT dose > 40 Gy (HR 0.21; p=0.005), number of metastases (HR 2.22; p=0.006) and maintenance SU (HR 0.31; p=0.06). Flow cytometry demonstrates a significant reduction in immune suppressive myeloid derived suppressor cells and T regulatory cells in SU treated patients.

Conclusions: Concurrent SU and IGRT achieves durable local and distant control in a significant subset of patients with oligometastases, particularly patients with genitourinary primary tumors with ≤ 2 distant metastases.

[Table: see text]

Preliminary evidence suggesting caution in the use of psychiatric self-report measures with adolescents with high-functioning autism spectrum disorders

This study investigated the utility of self-report measures to screen for psychiatric comorbidities in autism spectrum disorders (ASDs). Thirty-eight 10-17 year olds with an ASD and without mental retardation completed: the Children's Depression Inventory-Short version (CDI-S), Revised Children's Manifest Anxiety Scale (RCMAS), Conners-Wells Adolescent Self-report Scale-Short edition (CASS-S), and Short Leyton Obsessional Inventory-Child Version (SLOI-CV). Their parents were interviewed with the Autism Comorbidity Interview-Present and Lifetime (ACI-PL) to establish psychiatric diagnoses. Sensitivity, specificity, positive and negative predictive values, and reliability coefficients were calculated for each self-report and compared to values from literature. The CDI-S and CASS-S yielded a high number of false negatives, with lower sensitivities and specificities in the sample than the literature. There was a nearly significant difference in total mean RCMAS scores between participants with and without anxiety, though again the means for both groups were below the threshold of concern. The SLOI-CV yielded a high false positive rate. All four instruments had reliability coefficients comparable to literature values. Results must be considered preliminary due to sample size. However, the findings suggest that although self-report instruments may provide useful information in the diagnosis of psychiatric comorbidities in ASD, caution must be exercised in their interpretation.

Intrathecal delivery of a mutant micro-opioid receptor activated by naloxone as a possible antinociceptive paradigm

Direct injection of double-stranded adeno-associated virus type 2 (dsAAV2) with a mu-opioid receptor (MOR) mutant [S4.45(196)A], and a reporter protein (enhanced green fluorescent protein) into the spinal cord (S2/S3) dorsal horn region of ICR mice resulted in antinociceptive responses to systemic injection of opioid antagonist naloxone without altering the acute agonist morphine responses and no measurable tolerance or dependence development during subchronic naloxone treatment. To develop further such mutant MORs into a therapeutic agent in pain management, a less invasive method for virus delivery is needed. Thus, in current studies, the dsAAV2 was locally injected into the subarachnoid space of the spinal cord by intrathecal administration. Instead of using the MORS196A mutant, we constructed the dsAAV2 vector with the MORS196ACSTA mutant, a receptor mutant in which naloxone has been shown to exhibit full agonistic properties in vitro. After 2 weeks of virus injection, naloxone (10 mg/kg s.c.) elicited antinociceptive effect (determined by tail-flick test) without tolerance (10 mg/kg s.c., b.i.d. for 6 days) and significant withdrawal symptoms. On the other hand, subchronic treatment with morphine (10 mg/kg s.c., b.i.d.) for 6 days induced significant tolerance (4.8-fold) and withdrawal symptoms. Furthermore, we found that morphine, but not naloxone, induced the rewarding effects (determined by conditioned place preference test). These data suggest that local expression of MORS196ACSTA in spinal cord and systemic administration of naloxone has the potential to be developed into a new strategy in the management of pain without addiction liability.

Genomic and functional analysis identifies CRKL as an oncogene amplified in lung cancer

DNA amplifications, leading to the overexpression of oncogenes, are a cardinal feature of lung cancer and directly contribute to its pathogenesis. To uncover novel such alterations, we performed an array-based comparative genomic hybridization survey of 128 non-small cell lung cancer cell lines and tumors. Prominent among our findings, we identified recurrent high-level amplification at cytoband 22q11.21 in 3% of lung cancer specimens, with another 11% of specimens exhibiting low-level gain spanning that locus. The 22q11.21 amplicon core contained eight named genes, only four of which were overexpressed (by transcript profiling) when amplified. Among these, CRKL encodes an adaptor protein functioning in signal transduction, best known as a substrate of the BCR-ABL kinase in chronic myelogenous leukemia. RNA interference-mediated knockdown of CRKL in lung cancer cell lines with (but not without) amplification led to significantly decreased cell proliferation, cell-cycle progression, cell survival, and cell motility and invasion. In addition, overexpression of CRKL in immortalized human bronchial epithelial cells led to EGF-independent cell growth. Our findings indicate that amplification and resultant overexpression of CRKL contributes to diverse oncogenic phenotypes in lung cancer, with implications for targeted therapy, and highlighting a role of adapter proteins as primary genetic drivers of tumorigenesis.

Focal amplification and oncogene dependency of GAB2 in breast cancer

DNA amplifications in breast cancer are frequent on chromosome 11q, in which multiple driver oncogenes likely reside in addition to cyclin D1 (CCND1). One such candidate, the scaffolding adapter protein, GRB2-associated binding protein 2 (GAB2), functions in ErbB signaling and was recently shown to enhance mammary epithelial cell proliferation, and metastasis of ERBB2 (HER2/neu)-driven murine breast cancer. However, the amplification status and function of GAB2 in the context of amplification remain undefined. In this study, by genomic profiling of 172 breast tumors, and fluorescence in situ hybridization validation in an independent set of 210 scorable cases, we observed focal amplification spanning GAB2 (11q14.1) independent of CCND1 (11q13.2) amplification, consistent with a driver role. Further, small interfering RNA (siRNA)-mediated knockdown of GAB2 in breast cancer lines (SUM52, SUM44PE and MDA468) with GAB2 amplification revealed a dependency on GAB2 for cell proliferation, cell-cycle progression, survival and invasion, likely mediated through altered phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) signaling. GAB2 knockdown also reduced proliferation and survival in a cell line (BT474) with ERBB2 amplification, consistent with the possibility that GAB2 can function downstream of ERBB2. Our studies implicate focal amplification of GAB2 in breast carcinogenesis, and underscore an oncogenic role of scaffolding adapter proteins, and a potential new point of therapeutic intervention.

IL-10 promoter gene polymorphisms and sustained response to combination therapy in Taiwanese chronic hepatitis C patients

BACKGROUND AND AIMS

Host genetic factors may affect clinical outcomes of hepatitis C virus (HCV) infection; however, the possible mechanisms remain largely unknown. The role of immunopathogenesis in chronic hepatitis C leads to extensive exploration of host immunity including inflammatory cytokines.

METHODS

We examined interleukin 10 (IL-10) promoter gene polymorphisms at positions -1082, -819, and -592 relative to transcription start site and studied their association with response to 24 weeks of pegylated interferon plus ribavirin treatment in 143 chronic hepatitis C patients, of whom 97 (67.8%) achieved a sustained virologic response (SVR). In addition, 134 healthy adults were used as controls.

RESULTS

Of chronic hepatitis C patients, 111 (77.6%) were genotype 1 infection, 32 (22.4%) were genotype 2 infection. Patients with sustained virologic response were younger and had higher pretreatment ALT levels than those without. No statistical difference was found between chronic hepatitis C patients who achieved SVR or not in terms of gender, HCV genotype, pretreatment HCV RNA levels, and severity of liver disease. The serum IL-10 levels were comparable between healthy controls and chronic hepatitis C patients as well as between HCV patients with and without SVR. The distribution of IL-10 promoter gene polymorphisms at positions -1082, -819, and -592 relative to transcription start site was comparable between HCV patients and healthy controls as well as HCV patients with and without SVR. A high frequency of ATA haplotype of common IL-10 promoter gene SNPs was found in both chronic hepatitis C patients (70.3%) and healthy controls (69.8%). However, ATA haplotype was not associated with SVR in chronic hepatitis C patients.

CONCLUSIONS

Our data fail to demonstrate the influence of IL-10 promoter gene polymorphisms on the response to combination therapy in Taiwanese chronic hepatitis C patients. The impact of genetic variations in IL-10 haplotype on the response to anti-HCV treatment among different ethnic populations deserves further examination.

Phase II trial of concurrent 5-fluorouracil, hydroxyurea, cetuximab, and intensity moduled radiation therapy (IMRT) for locally advanced head and neck cancer

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Background: This phase II study was conducted to evaluate the tolerability and efficacy of incorporating cetuximab and simultaneous integrated boost intensity modulated radiation (SIB-IMRT) into a well-described 5-fluorouracil (5-FU) and hydroxyurea (HU)-based chemoradiation regimen. Endpoints included overall survival (OS), locoregional (LRC) and (DC), quality of life and toxicity. Methods: Patients with stage IVa-IVb or high-risk stage III squamous cell carcinomas were enrolled on a phase II trial. Prior organ-conserving surgical therapy or induction chemotherapy was allowed off protocol. SIB-IMRT was prescribed to low (43.2 to 48 Gy) and intermediate (54 to 63 Gy) risk volumes. A separate IMRT conedown plan was targeted to gross disease (72 Gy). The median radiation dose was 72 Gy (range 60 to 72 Gy) administered in 1.5 Gy fractions BID on weeks 1, 3, 5, 7 ± 9. Concurrent systemic therapy consisted of 5-FU (600 mg/m2), HU (500 mg BID) and cetuximab (250 mg/m2). Results: From January 2007 to April 2008, 33 subjects enrolled. Characteristics included 24 males; median age 59; ECOG performance status was 0 in 12. Disease was stage IVa-b disease in 31 (94%), T3–4 in 16 (48%), N2–3 in 23 (70%), and oropharynx primary in 15 (45%). Median follow-up in surviving patients is 15 months (range 6 to 22 months). The 1 year LRC, DC and OS is 91%, 82%, and 92%, respectively. Grade 3 toxicity consisted of mucositis (33%), radiation dermatitis (15%), anemia (15%), and leukopenia (15%), and neutropenia (9%). There were no grade 4–5 events. The majority of patients (64%) were able to tolerate treatment without a feeding tube. Median patient reported University of Washington QOL-R scores before, immediately after, 3 months and 8 months after chemoradiation were 85.5 (±14), 65 (±13), 76.5 (±15), and 84.5 (±9), respectively. Conclusions: Concurrent 5-FU, HU, cetuximab, and SIB-IMRT is a promising and reasonably well tolerated approach to incorporating molecularly targeted therapy in the curative therapy of locally advanced head and neck cancer.

[Table: see text]

One-Stage Reconstruction of the Penis with Free Skin Flap: Report of Three Cases

Three cases of penile defect of varying extent were reconstructed with free skin flaps from the forearm based on the radial artery. In two cases, part of the forearm flap was used to reconstruct the urethra, and the rest of the flap to reconstruct the corpus penis. A piece of autogenous cartilage was then inserted between the two layers. All procedures were completed in a one-stage operation. In the third case, a free skin graft was used for urethral reconstruction. Surgery in all three cases was successful, providing a penis of acceptable appearance as well as excellent urinary function.

Genomic profiling identifies TITF1 as a lineage-specific oncogene amplified in lung cancer

Lung cancer is a leading cause of cancer death, where the amplification of oncogenes contributes to tumorigenesis. Genomic profiling of 128 lung cancer cell lines and tumors revealed frequent focal DNA amplification at cytoband 14q13.3, a locus not amplified in other tumor types. The smallest region of recurrent amplification spanned the homeobox transcription factor TITF1 (thyroid transcription factor 1; also called NKX2-1), previously linked to normal lung development and function. When amplified, TITF1 exhibited increased expression at both the RNA and protein levels. Small interfering RNA (siRNA)-mediated knockdown of TITF1 in lung cancer cell lines with amplification led to reduced cell proliferation, manifested by both decreased cell-cycle progression and increased apoptosis. Our findings indicate that TITF1 amplification and overexpression contribute to lung cancer cell proliferation rates and survival and implicate TITF1 as a lineage-specific oncogene in lung cancer.

Effect of adjuvant radiotherapy (RT) on overall survival (OS) for node positive head and neck squamous cell carcinoma (HNSCC)

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Background: Although adjuvant RT is often recommended for locally advanced HNSCC, its effect on OS or cancer-specific survival (CSS) has not been clearly demonstrated. Methods: Within the Surveillance, Epidemiology, and End Results (SEER) Database, we selected patients with locally invasive but node negative (SEER stage 2) or node positive HNSCC (SEER stage 3–4) treated either with surgery alone (S) or surgery and radiation (S+RT). This analysis included 13,145 patients from the SEER 17 database diagnosed between 1988 and 2001. Exclusion criteria included distant metastases, no RT records or death within 3 months of surgery. The median follow-up was 4.7 years. Results: Adjuvant RT was utilized in 55% of patients with stage 2 and 84% of stage 3–4 HNSCC. For Stage 2 HNSCC, adjuvant RT was associated with lower 5 year OS on univariate analysis (46.32% for S+RT vs. 49.76% for S, p=0.016) but not on multivariate analysis (HR 1.00, p=0.93). For Stage 3 HNSCC, RT improved 5 year OS associated with RT on univariate analysis (52% for S + RT vs. 41% for S, p<0.001) and multivariate analysis (HR 0.80, p=0.002). For Stage 4 HNSCC, RT significantly improved 5 year OS on univariate analysis (35% for S + RT vs. 25% for S, p<0.001) and multivariate analysis (HR 0.75, p<0.001). The addition of RT improved 5 year CSS for both stage 3 (59.7% vs. 51.4%) and stage 4 HNSCC (42.1% vs. 32.8%). Conclusions: In the largest reported analysis of adjuvant RT in locally advanced HNSCC, adjuvant RT results in an approximately 10% absolute increase in 5-year CSS and OS for node-positive HNSCC compared to S alone. The absolute benefit of RT is underestimated on univariate analysis because patients with poor prognostic factors are more frequently selected for adjuvant RT. Outcomes in this high-risk population remain suboptimal, emphasizing the need for continued investigation of innovative treatment approaches.

No significant financial relationships to disclose.

Diagnosis of renal tumors on needle biopsy specimens by histological and molecular analysis

PURPOSE

We diagnosed the subtypes of renal cell carcinoma on needle core biopsies using a combination of histopathology and a molecular diagnostic algorithm.

MATERIALS AND METHODS

Core biopsies were taken of renal tumors following nephrectomy. RNA was extracted and quantitative real-time polymerase chain reaction was performed for 4 gene products to differentiate among renal cell carcinoma subtypes. Histopathological diagnosis was achieved on a second core before and after obtaining the molecular diagnostic algorithm results.

RESULTS

Based on the nephrectomy diagnosis 6 of 77 renal masses were nonneoplastic and 71 were tumors, including 65 renal cell carcinoma/oncocytomas. The overall diagnostic accuracy using histology and our molecular diagnostic algorithm combined was 90.0% (70 of 77). Side by side comparison of histology vs molecular diagnostic algorithm was feasible for 60 classifiable renal cell carcinoma/oncocytomas (31 clear cell, 14 papillary renal cell carcinoma, 6 chromophobe renal cell carcinoma, 2 mucinous tubular and spindle cell carcinoma, and 7 oncocytoma). In this group histology correctly predicted the final histological subtype in 83.3% (50 of 60) of cores. Addition of the molecular diagnostic algorithm to histology improved the subtyping accuracy to 95% (57 of 60), whereas the molecular diagnostic algorithm alone was accurate in 50 of 60 cases (83.3%). Dividing these 60 specimens into clear cell and nonclear cell neoplasms, the addition of the molecular diagnostic algorithm improved the sensitivity for the diagnosis of clear cell carcinoma from 87.1% (27 of 31) to 100% and the negative predictive value from 87.5% to 100%.

CONCLUSIONS

Core biopsies of renal tumors provide adequate material for diagnosing and subtyping renal cell carcinoma. The addition of our molecular diagnostic algorithm to histology improved the diagnostic accuracy of core biopsies of renal masses.

gamma-H2AX as a therapeutic target for improving the efficacy of radiation therapy

Exposure to ionizing radiation (IR) results in the formation of DNA double strand breaks, resulting in the activation of phosphatidylinositol 3'-kinase-like kinases ATM, ATR and DNK-PKcs. A physiologically important downstream target is the minor histone H2A variant, H2AX, which is rapidly phosphorylated on Ser 139 of the carboxyl tail after IR. Recent work suggests that phosphorylated H2AX (gamma-H2AX) plays an important role in the recruitment and/or retention of DNA repair and checkpoint proteins such as BRCA1, MRE11/RAD50/NBS1 complex, MDC1 and 53BP1. H2AX-/- mouse embryonic fibroblasts are radiation sensitive and demonstrate deficits in repairing DNA damage compared to their wildtype counterparts. Cells treated with peptide inhibitors of gamma-H2AX demonstrate increased radiosensitivity following radiation compared with untreated irradiated cells. Analysis of the kinetics of gamma-H2AX clearance after IR or other DNA damaging agents reveals a correlation between increased gamma-H2AX persistence and unrepaired DNA damage and cell death. These data highlight the potential of post-translational modifications of chromatin as a therapeutic target for enhancing the efficacy of radiotherapy. Therapies that either block gamma-H2AX foci formation by inhibiting upstream kinase activity or that directly inhibit H2AX function may interfere with DNA damage repair processes and warrant further investigation as potential radiosensitizing agents. Agents that increase persistence of gamma-H2AX after IR are likely to increase unrepaired DNA damage.

Use of canalicular membrane vesicles (CMVs) from rats, dogs, monkeys and humans to assess drug transport across the canalicular membrane

INTRODUCTION

A novel application of a Ultrafree filter cartridge/centrifugation method was evaluated to determine uptake in canalicular membrane vesicles (CMVs) from SD rats, beagle dogs, cynomolgus monkeys (common safety species in the pharmaceutical industry) and humans to assess biliary transport.

METHODS

CMVs prepared from fresh livers of rats, dogs, monkeys and humans (four donors) were characterized for enrichment, basolateral and Golgi contamination and orientation. The presence of MRP2 and p-glycoprotein (P-gp) were confirmed by Western blots. Uptake of [3H]-leukotriene C4 (LTC4) and [3H]-estradiol-17beta-d-glucuronide (E2-Gluc) was determined at a low substrate concentration and/or by kinetic measurements (K(m) and V(max)). Correlation of in vitro data with in vivo findings was achieved by determining the biliary clearance of E2-Gluc in rats after a single i.v. dose and with literature in vivo data for LTC4.

RESULTS

CMVs were highly enriched and minimally contaminated based on marker enzyme activities. Uptake clearance among different species varied by approximately ten-fold (rat > dog = human > monkey) for LTC4 and less than two-fold for E2-Gluc. The lower uptake of LTC4 by human than rat CMVs may be attributed to a higher Km value for human than rat CMVs. Uptake of LTC4 or E2-Gluc by human CMVs showed little inter-subject variability (2-5-fold). Differences in in vitro uptake clearance (10-fold) between LTC4 and E2-Gluc in rat CMVs seemed to correlate with differences in their biliary clearance (4-fold) in rats, consistent with LTC4 and E2-Gluc being a high and a low clearance substrate, respectively.

DISCUSSION

A novel application of a Ultrafree filter cartridge/centrifugation method was developed to determine uptake in CMVs from different preclinical animal safety species and humans, and may represent a useful approach to study the mechanism of biliary excretion during drug discovery and development.

Sparing of the penile bulb and proximal penile structures with intensity-modulated radiation therapy for prostate cancer

Quality of life is an important consideration in the treatment of early prostate cancer. Laboratory and clinical data suggest that higher radiation doses delivered to the bulb of penis and proximal penile structures correlates with higher rates of post-radiation impotence. The goal of this investigation was to determine if intensity-modulated radiation therapy (IMRT) spares dose to the penile bulb while maintaining coverage of the prostate. 10 consecutive patients with clinically organ confined prostate cancer were planned with 3D conformal radiation therapy (3D-CRT) or IMRT to give a dose of 74 Gy without specifically constraining the plans to spare the penile bulb. All 10 patients were ultimately treated with IMRT. Dose-volume histograms were evaluated and the doses to prostate, rectum, bladder and penile bulb were compared. IMRT reduced the mean penile bulb doses compared with 3D-CRT (33.2 Gy vs 48.9 Gy, p<0.001), the percentage of penile bulb receiving over 40 Gy (37.7% vs 67.2%, p<0.001) and the dose received by >95% of penile bulb (5.3 Gy vs 11.7 Gy, p=0.003). Maximum penile bulb doses were higher with IMRT (81.2 Gy vs 73.1 Gy, p<0.001) although the volume of this high dose region was small. Both methods resulted in similar coverage of the prostate. The volume of rectum receiving 70 Gy was significantly reduced with IMRT (18.4% vs 21.9%, p=0.003) but the volumes of bladder receiving 70 Gy were similar (p=0.3). IMRT may potentially reduce long term sexual morbidity by reducing the dose to the majority of the penile bulb.