Impact of neoadjuvant chemotherapy on survival and recurrence patterns after robot-assisted radical cystectomy for muscle-invasive bladder cancer: Results from the International Robotic Cystectomy Consortium

OBJECTIVES

To analyze the impact of neoadjuvant chemotherapy on survival and recurrence patterns in muscle-invasive bladder cancer after robot-assisted radical cystectomy.

MATERIALS AND METHODS

The International Robotic Cystectomy Consortium database was reviewed to identify patients who underwent robot-assisted radical cystectomy for muscle-invasive bladder cancer between 2002 and 2019. Survival outcomes, response rates, and recurrence patterns were compared between patients who received neoadjuvant chemotherapy and those who did not. Survival distributions were estimated using Kaplan-Meier analyses and compared using the log-rank test.

RESULTS

A total of 1370 patients with muscle-invasive bladder cancer were identified, of whom 353 (26%) received neoadjuvant chemotherapy. After a median follow-up of 27 months, neoadjuvant chemotherapy recipients had higher 3-year overall survival (74% vs 57%; log-rank P < 0.01), 3-year cancer-specific survival (83% vs 73%; log-rank P = 0.03), and 3-year relapse-free survival (64% vs 48%; log-rank P < 0.01). Neoadjuvant chemotherapy was a predictor of higher overall survival, cancer-specific survival, and relapse-free survival in univariate but not multivariate analysis. Pathological downstaging (46% vs 23%; P < 0.01), complete responses (24% vs 8%; P < 0.01), and margin negativity (95% vs 91%; P < 0.01) at robot-assisted radical cystectomy were more common in the neoadjuvant chemotherapy group. Neoadjuvant chemotherapy recipients had lower distant (15% vs 22%; P < 0.01) but similar locoregional (12% vs 13%; P = 0.93) recurrence rates.

CONCLUSIONS

In this analysis from a large international database, patients with muscle-invasive bladder cancer who received neoadjuvant chemotherapy before robot-assisted radical cystectomy had higher rates of survival, pathological downstaging, and margin-negative resections. They also experienced fewer distant recurrences.

Studying the urine microbiome in superficial bladder cancer: samples obtained by midstream voiding versus cystoscopy

BACKGROUND

Preliminary data suggest that the urinary microbiome may play a role in bladder cancer. Information regarding the most suitable method of collecting urine specimens is needed for the large population studies needed to address this. To compare microbiome metrics resulting from 16S ribosomal RNA gene sequencing between midstream, voided specimens and those obtained at cystoscopy.

METHODS

Adults, with a history of superficial urothelial cell carcinoma (non-muscle invasive bladder cancer) being followed with periodic surveillance cystoscopy had a urine sample collected by a mid-stream, voided technique and then from the bladder at cystoscopy. Urine samples underwent 16S ribosomal RNA gene sequencing on the Illumina MiSeq platform.

RESULTS

22 subjects (8 female, 14 male) were included. There was no significant difference in beta diversity (diversity between samples) in all samples between collection methods. However, analysis by sex revealed a difference between voided and cystoscopy samples from the same individual in males (p = 0.006, Adonis test) but not in females (p = 0.317, Adonis test). No differences were seen by collection method in any alpha diversity (diversity within a sample) measurement or differential abundance of taxa.

CONCLUSIONS

Beta diversity of the urine microbiome did differ by collection method for males only. This suggests that the urinary microbiomes of the two collection methods are not equivalent to each other, at least in males, which is the sex that bladder cancer occurs most frequently in. Therefore, the same collection method within a given study should be used.

Abstract 4625: Tumor expression of PIM kinases in renal cell carcinoma and the association with disease progression

Hypoxia-inducible factor (HIF) plays an important role in the tumorigenesis of renal cell carcinoma (RCC). Mutational inactivation of the von Hippel-Lindau (VHL) tumor suppressor gene, which is the most frequent molecular event, has been implicated in HIF overexpression. Recent studies found that PIM kinases increase HIF expression in cancer. The PIM Kinases are a family of highly conserved serine/threonine kinases consisting of three isoforms (PIM1, PIM2, and PIM3). PIM kinases play multiple roles in promoting cell proliferation and survival and preventing apoptosis. The expression and the potential function of PIM kinases in RCC remain unclear. Thus, we examined the expression patterns and the clinical significance of the three individual PIM kinases in RCC. PIM expression was examined by immunohistochemical staining tumor tissue and adjacent non-tumor tissue samples from 218 patients with clear cell RCC (ccRCC), including 60 patients with metastatic ccRCC. The expression of each PIM kinase in primary and metastatic ccRCC tissues comparing with adjacent normal tissues was analyzed with variables including tumor stage, grade and survival. Effect of PIM kinase on cell growth in ACHN and 786-O RCC cell lines was examined by individual PIM knockdown with specific siRNA followed by in vitro proliferation assay. Effect of PIM kinase on RCC cell motility was examined by siRNA followed by in vitro Matrigel-based invasion assay. Expression of PIM1, PIM2 and PIM3 was detected in the majority of ccRCC samples (185, 85%), but localization of isoforms differed. PIM1 expression was higher in the nucleus than in cytoplasm, while the reverse was true for PIM 2 and 3. PIM2 and PIM3 expression was higher in cytoplasm than in the nucleus. Higher expression of PIM1 and PIM2 in tumor tissues was significantly associated with metastasis. Nuclear PIM2 was associated with poorly differentiated ccRCC cells. ccRCC patients with increased nuclear PIM2 expression had significantly poorer survival compared with patients with low nuclear PIM2. siRNA-PIM2, but not siRNA-PIM1 and siRNA-PIM3, significantly reduced proliferation of ACHN and 786-O cells. Further, knockdown of PIM2 by siRNA reduced the ability of cell invasion in 786-O cells. In conclusion, PIM kinases, especially PIM2, are associated with ccRCC progression, indicating that PIM kinases may serve as potential markers for metastatic ccRCC. Targeting PIM kinases may have a therapeutic potential in ccRCC. This work was supported by NIH/NCI grant CA067267, CA085142 (Johnson, CS) and National Cancer Institute (NCI) grant P30 CA016056 involving the use of Roswell Park Cancer Institute's Bioinformatics, Pathology Resource Network, Genomics, and Clinical Data Network Shared Resources.

Citation Format: Wei Luo, Yingyu Ma, Eduardo Cortes, Angela Omilian, Wiam Bshara, Gissou Azabdaftari, Brittany Bunch, Candace Johnson, Donald Trump. Tumor expression of PIM kinases in renal cell carcinoma and the association with disease progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4625.

Identification of XLRS1 Gene Mutation (608C>T) in a Portuguese Family with Juvenile Retinoschisis

Purpose

To characterize electroretinogram (ERG) and molecular genetic findings in a family with XLRS1 mutation. The authors present two cases of a Portuguese family with juvenile retinoschisis with a mutation in exon 6.

Methods

Two brothers and their parents, grandmother, and uncle underwent a full ophthalmic examination. The two brothers with ophthalmic disease were evaluated with color fundus photography, fluorescein angiography, optical coherence tomography (OCT), molecular genetic study (Group VI of Retinoschisis Consortium), pattern visual evoked potential (PVEP), and full field ERG.

Results

Both patients presented funduscopic manifestations of vitreoretinal degeneration. They presented peripheral schisis and retinal detachment. However, foveal schisis had never been observed at funduscopy. A negative ERG was recorded in both. Six months after that, the younger brother showed a typical foveal schisis at fundus examination. A retinoschisis gene (XLRS1) mutation with transition of cytosine by thymine at position 608 (608C>T) had been identified in both.

Conclusions

Negative ERG is the most secure clinical marker to establish the diagnosis of juvenile retinoschisis. XLRS1 gene 608C>T mutation was described for the first time in a Portuguese family.

Abstract 1086: Vitamin D3 increases the response to cisplatin in bladder cancer through VDR and TAp73 pathway crosstalk

Neoadjuvant cisplatin-based chemotherapy is used to treat muscle invasive bladder cancer (MIBC); however the relative 5-year survival of advanced disease is only 15%. The two major pitfalls of neoadjuvant chemotherapy are delaying cystectomy in patients with poor response to cisplatin, and the lack of available biomarkers to identify these patients. Previous studies in our lab showed that pretreatment of preclinical bladder cancer models with 1,25 dihydroxyvitamin D3 (1,25D3), the active metabolite of vitamin D3, enhances the apoptotic response to cisplatin. Mechanistic understanding can provide insight into potential markers for response to 1,25D3 and cisplatin combination therapy in patients. Greater than 50% of MIBCs harbor p53 mutations; however p53 status has not been linked to clinical response to cisplatin. We previously determined that TAp73, a pro-apoptotic p53 family member protein induced after DNA damage, is required for the response to 1,25D3 and cisplatin. In two bladder cancer cell lines with mutant p53, T24 and RT-112, we identified signaling crosstalk between the vitamin D receptor (VDR) and TAp73. Treatment with 1,25D3 and cisplatin, compared to either alone, results in greatest increase of TAp73 mRNA and protein, 2-fold (T24) and 15-fold (RT-112), as well as TAp73 transcriptional target BAX, 3-fold (T24), and 4-fold (RT-112). TAp73 and BAX induction is lost in cells transfected with VDR siRNA, indicating a requirement for VDR. Cells treated with 1,25D3 and cisplatin, compared to either alone, also show the greatest increase of VDR mRNA and protein, 3-fold (T24) and 4-fold (RT-112). CYP24A1, a VDR target gene, has the greatest induction after the combination treatment as well, with an increase of approx. 60-fold (T24), and 100-fold (RT-112). CYP24A1 induction requires TAp73, determined using TAp73 shRNA. These data demonstrate that VDR signaling is enhanced by cisplatin treatment, and TAp73 signaling is enhanced by 1,25D3. We expanded these findings in vivo by treating mice on a vitamin D3 sufficient diet (1,000 IU) or a vitamin D3 deficient diet (25 IU) with 5 mg/kg of cisplatin (IP, q.wk for 3 weeks). Initially, mice on both diets respond to cisplatin treatment, as evidence by a 30% reduction in tumor volume. After the second cycle of treatment, tumors in the deficient mice stopped responding and returned to their initial tumor volume within 24 days. In the sufficient mice, tumors continued to respond to cisplatin with a maximum reduction of 50%. This was maintained for approximately 40 days after treatment. Further study will determine the molecular response to confirm our in vitro mechanism. Our work suggests that vitamin D3 is important in and can increase the response to cisplatin, it also provides rationale for investigating TAp73 protein levels and serum vitamin D3 levels as potential markers to determine patients’ likelihood of responding to cisplatin.

Citation Format: Brittany L. Bunch, Donald Trump, Candace S. Johnson. Vitamin D3 increases the response to cisplatin in bladder cancer through VDR and TAp73 pathway crosstalk [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1086. doi:10.1158/1538-7445.AM2017-1086

Tyrosinemia type II: Mutation update, 11 novel mutations and description of 5 independent subjects with a novel founder mutation

BACKGROUND

Tyrosinemia type II, also known as Richner-Hanhart Syndrome, is an extremely rare autosomal recessive disorder, caused by mutations in the gene encoding hepatic cytosolic tyrosine aminotransferase, leading to the accumulation of tyrosine and its metabolites which cause ocular and skin lesions, that may be accompanied by neurological manifestations, mostly intellectual disability.

AIMS

To update disease-causing mutations and current clinical knowledge of the disease.

MATERIALS AND METHODS

Genetic and clinical information were obtained from a collection of both unreported and previously reported cases.

RESULTS

We report 106 families, represented by 143 individuals, carrying a total of 36 genetic variants, 11 of them not previously known to be associated with the disease. Variants include 3 large deletions, 21 non-synonymous and 5 nonsense amino-acid changes, 5 frameshifts and 2 splice variants. We also report 5 patients from Gran Canaria, representing the largest known group of unrelated families sharing the same P406L mutation.

CONCLUSIONS

Data analysis did not reveal a genotype-phenotype correlation, but stressed the need of early diagnosis: All patients improved the oculocutaneous lesions after dietary treatment but neurological symptoms prevailed. The discovery of founder mutations in isolated populations, and the benefits of early intervention, should increase diagnostic awareness in newborns.

Abstract 806: SNPs in vitamin D-related genes are associated with prostate cancer aggressiveness in the North Carolina-Louisiana Prostate Cancer Project (PCaP)

Introduction: African Americans have higher incidence of, and mortality from, prostate cancer (PCa) compared to other racial/ethnic groups. Frequency of polymorphisms in genes involved in vitamin D metabolism, transport, and activity differ by race/ethnicity. Examining the association between polymorphisms in vitamin D-related genes and PCa aggressiveness may explain differing susceptibility to aggressive PCa among individuals and across different racial/ethnic groups.

Methods: TagSNPs (n = 315) in 13 genes (VDR, GC, CYP24A1, CYP27A1, CYP27B1, CYP2R1, CYP3A4, DHCR7, CASR, NADSYN1, RXRA, RXRB, RXRG) were genotyped using Illumina GoldenGate or Sequenom assays in 524 African-American and 657 European-American men with newly-diagnosed PCa from PCaP. DNA extracted from blood samples collected at enrollment was stored at -80C prior to analyses. Research subjects were classified as high aggressive if Gleason sum ≥8, or Gleason score (4+3), or PSA &gt;20 ng/ml, or Gleason score (3+4) AND clinical stage = T3-T4. The comparison group (low aggressive) included research subjects with Gleason sum &lt;7 AND Stage T1-T2 AND PSA &lt; 9 ng/ml. Odds ratios (OR) and 95% confidence intervals (95%CI) were calculated for high aggressive PCa for each SNP using logistic regression with adjustment for age and proportion of African ancestry. Associations were considered statistically significant at p&lt;0.05. A polygenic score based on a previous study of SNP predictors of serum 25-hydroxy-vitamin D levels was calculated utilizing SNPs in the GC, CYP24A1, CYP2R1, and NADSYN1 genes.

Results: Among African Americans, 21 SNPs were associated with PCa aggressiveness. The variant allele was associated negatively or positively with high aggressive PCa in eleven and ten SNPs, respectively. For example, two SNPs in the vitamin D binding protein gene known as GC, were inversely associated (rs222054: OR, 0.55, 95%CI, 0.38-0.80; and rs16847028: OR, 0.61, 95%CI, 0.39-0.94). Among European Americans, the variant allele was inversely associated with high aggressive PCa for four SNPs in three genes (CASRrs3863977; CYP24A1rs4809960; RXRArs1007971; and RXRArs3118526), and positively associated with high aggressive PCa for three SNPs in the CYP27B1 gene (rs703842, rs4646536, and rs10877013). There was no association between higher number of ‘low vitamin D’ alleles in the four SNPs that comprised the polygenic score and PCa aggressiveness for either race.

Conclusions: Polymorphisms in genes involved in vitamin D etabolism and activity, the vitamin D binding protein and calcium sensing receptor were associated with PCa aggressiveness, and there was no overlap in SNPs between race groups. Our ongoing work will examine interaction between polymorphisms of vitamin D-related genes and vitamin D metabolite levels on PCa aggressiveness.

Citation Format: Susan E. Steck, Anna Woloszynska-Read, Samuel Antwi, Hongmei Zhang, Lenore Arab, Elizabeth T.H. Fontham, James Mohler, L. Joseph Su, Feifei Xiao, Gary Smith, Donald Trump, Candace Johnson, Jeannette Bensen. SNPs in vitamin D-related genes are associated with prostate cancer aggressiveness in the North Carolina-Louisiana Prostate Cancer Project (PCaP). [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 806.

Abstract 5056: PIM-1 kinase regulates vitamin D receptor signaling in human renal carcinoma cells

Dysregulation of vitamin D signaling and metabolism enzymes is a frequent change in many cancers and may confound approaches to vitamin -D based therapies. The mechanisms by which aberrant vitamin D signaling and metabolism lead to resistance to vitamin D action are poorly understood. The kidney plays a critical role in vitamin D synthesis and metabolism; in renal cell carcinoma (RCC) cells vitamin D metabolism is dysregulated. Recently, we discovered that an oncogenic protein kinase PIM-1 is involved in vitamin D-induced expression of 24-hydroxylase, a key catalytic enzyme of vitamin D encoded by CYP24A1 gene, in bladder and prostate cancer. To study the impact of PIM1 on vitamin D signaling and vitamin D-mediated anti-tumor activity in RCC, we analyzed 4 human renal cell carcinoma cell lines (Caki-1, ACHN, A498 and 786-O) and 25 samples of human RCC tumor tissue and 13 benign kidney tissues (including 10 matched tumor and benign tissue samples) by qRT-PCR, immunohistochemistry (IHC), Western blot analysis, MTT and clonogenic assays. VDR mRNA and protein were detected in all RCC cell lines. IHC showed that VDR was strongly expressed in the normal kidney tissues, but decreased in RCC tissues. As expected, VDR expression was significantly increased by treatment with 1,25-dihydroxyvitamin D3 (1,25D3) in RCC cell lines. MTT and clonogenic assays showed that 1,25D3 inhibited RCC cell growth (p&lt;0.05). We also noted a significant increase of CYP24A1 expression induced by vitamin D3 (p&lt;0.0001); and effect which would be expected to promote the catabolism of 1,25D3. qRT-PCR and Western blot analysis demonstrated that PIM-1 is expressed in RCC cells. PIM-1 inhibition by siRNA or PIM-1 inhibitor JP_11646 significantly reduced 1,25D3-induced CYP24A1 expression (p&lt;0.05). Therefore, we hypothesized that targeting PIM-1 kinase activity with a PIM-1 inhibitor may be an effective strategy to reduce 1,25D3 metabolism, thereby enhancing vitamin D-mediated anti-tumor activity. Inhibition of PIM1 kinase activity by JP_11646 reduced CYP24A1 expression at the transcriptional level in RCC cells. We further evaluated the efficacy of the PIM1 inhibitor alone or in combination with 1,25D3. Inhibition of PIM1 kinase activity by JP_11646 reduced cell growth in RCC cell lines in a dose-dependent manner as measured by MTT and clonogenic assays. Furthermore, inhibition of PIM1 kinase activity enhances 1,25D3-mediated inhibitory effect on cell growth in RCC cells (p&lt;0.05). This study indicates that PIM-1 is involved in the regulation of vitamin D signaling in RCC. Inhibition of PIM kinase activity combined with vitamin D may be an attractive new therapeutic strategy for RCC.

Citation Format: Wei Luo, Yingyu Ma, Carmen Baldino, Justin Caserta, Swathi Ramakrishnan, Pili Roberto, Candace Johnson, Donald Trump. PIM-1 kinase regulates vitamin D receptor signaling in human renal carcinoma cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5056. doi:10.1158/1538-7445.AM2015-5056

Commentary on: "Randomized, controlled, double-blind, cross-over trial assessing treatment preference for pazopanib versus sunitinib in patients with metastatic renal cell carcinoma: PISCES study." Escudier B, Porta C, Bono P, Powles T, Eisen T, Sternberg CN, Gschwend JE, De Giorgi U, Parikh O, Hawkins R, Sevin E, Négrier S, Khan S, Diaz J, Redhu S, Mehmud F, Cella D. Bernard Escudier, Institut Gustave Roussy, Villejuif; Emmanuel Sevin, Centre François Baclesse, Caen; Sylvie Négrier, Leon Berard Cancer Center, Lyon, France; Camillo Porta, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Policlinico S. Matteo, Pavia; Cora N Sternberg, San Camillo Forlanini Hospital, Rome; Ugo De Giorgi, IRCCS Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori, Meldola, Italy; Petri Bono, Helsinki University Central Hospital, Helsinki, Finland; Thomas Powles, Barts Experimental Cancer Medicine Centre, Barts Cancer Institute, Queen Mary University of London, London; Tim Eisen, Cambridge University Health Partners, Cambridge; Omi Parikh, Royal Preston Hospital, Lancashire; Robert Hawkins, Christie Cancer Research UK, Manchester; Sadya Khan, Jose Diaz, and Faisal Mehmud, GlaxoSmithKline, Uxbridge, United Kingdom; Jürgen E Gschwend, Klinikum Rechts der Isar der Technischen Universität München, Munich, Germany; Suman Redhu, GlaxoSmithKline, Collegeville, PA; David Cella, Northwestern University Feinberg School of Medicine, Chicago, IL.: J Clin Oncol. 2014 May 10;32(14):1412-1418; doi: 10.1200/JCO.2013.50.8267. [Epub 2014 Mar 31]

PURPOSE

Patient-reported outcomes may help inform treatment choice in advanced/metastatic renal cell carcinoma (RCC), particularly between approved targeted therapies with similar efficacy. This double-blind crossover study evaluated patient preference for pazopanib or sunitinib and the influence of health-related quality of life (HRQoL) and safety factors on their stated preference.

PATIENTS AND METHODS

Patients with metastatic renal cell carcinoma were randomly assigned to pazopanib 800mg per day for 10 weeks, a 2-week washout, and then sunitinib 50mg per day (4 weeks on, 2 weeks off, 4weeks on) for 10 weeks, or the reverse sequence. The primary end point, patient preference for a specific treatment, was assessed by questionnaire at the end of the two treatment periods. Other end points and analyses included reasons for preference, physician preference, safety, and HRQoL.

RESULTS

Of 169 randomly assigned patients, 114 met the following prespecified modified intent-to-treat criteria for the primary analysis: exposure to both treatments, no disease progression before cross over, and completion of the preference questionnaire. Significantly more patients preferred pazopanib (70%) over sunitinib (22%); 8% expressed no preference (P<.001). All preplanned sensitivity analyses, including the intent-to-treat population, statistically favored pazopanib. Less fatigue and better overall quality of life were the main reasons for preferring pazopanib, with less diarrhea being the most cited reason for preferring sunitinib. Physicians also preferred pazopanib (61%) over sunitinib (22%); 17% expressed no preference. Adverse events were consistent with each drug׳s known profile. Pazopanib was superior to sunitinib in HRQoL measures evaluating fatigue, hand/foot soreness, and mouth/throat soreness.

CONCLUSION

This innovative crossover trial demonstrated a significant patient preference for pazopanib over sunitinib, with HRQoL and safety as key influencing factors.

Commentary on: "Enzalutamide monotherapy in hormone-naive prostate cancer: primary analysis of an open-label, single-arm, phase 2 study." Tombal B, Borre M, Rathenborg P, Werbrouck P, Van Poppel H, Heidenreich A, Iversen P, Braeckman J, Heracek J, Baskin-Bey E, Ouatas T, Perabo F, Phung D, Hirmand M, Smith MR. Institut de Recherche Clinique, Université Catholique de Louvain, Brussels, Belgium. Electronic address: bertrand.tombal@uclouvain.be. Aarhus University Hospital, Aarhus, Denmark. Herlev Hospital, Herlev, Denmark. AZ Groeninge Kortrijk, Kortrijk, Belgium. UZ Leuven, Leuven, Belgium. Klinik und Poliklinik für Urologie, RWTH University Aachen, Aachen, Germany. Rigshospitalet, University of Copenhagen, Copenhagen, Denmark. UZ Brussel, Brussels, Belgium. Univerzita Karlova v Praze, Prague, Czech Republic. Astellas Pharma Global Development, Leiden, Netherlands. Astellas Pharma Global Development, Northbrook, IL, USA. Medivation Inc, San Francisco, CA, USA. Massachusetts General Hospital Cancer Center, Boston, MA, USA: Lancet Oncol. 2014 May;15(6):592-600; doi: 10.1016/S1470-2045(14)70129-9. [Epub 2014 Apr 14]

BACKGROUND

The androgen receptor inhibitor enzalutamide is approved for the treatment of metastatic castration-resistant prostate cancer that has progressed on docetaxel. Our aim was to assess the activity and safety of enzalutamide monotherapy in men with hormone-naive prostate cancer.

METHODS

This trial is an ongoing open-label, single-arm, phase 2 study, done across 12 European sites. Men aged over 18 years with hormone-naive prostate cancer for whom hormone therapy was indicated, and who had noncastration levels of testosterone and prostate-specific antigen (PSA) of 2ng/mL or greater at screening, and an Eastern Cooperative Oncology Group score of 0, received oral enzalutamide 160mg/day. The primary outcome was the proportion of patients with an 80% or greater decline in PSA at week 25. All analyses included all patients who had received at least one dose of the study drug. This study is registered with ClinicalTrials.gov, number NCT01302041.

FINDINGS

67 men were enrolled into the study. 62 patients (92.5%, 95% CI: 86.2-98.8) had a decline in PSA of 80% or greater at week 25. The most commonly reported treatment-emergent adverse events up to week 25 were gynaecomastia (n = 24), fatigue (n = 23), nipple pain (n = 13), and hot flush (n = 12), all of which were of mild to moderate severity. Overall, 9 patients had a treatment-emergent adverse event of grade 3 or higher, most of which were reported in one patient each, except for pneumonia (grade 3, two patients) and hypertension (grade 3, four patients). Five patients reported serious adverse events, none of which were deemed to be treatment related.

INTERPRETATION

Our findings suggest that enzalutamide monotherapy in men with hormone-naive prostate cancer of varying severity provides a level of disease suppression and was generally well tolerated. These findings provide a rationale for further investigation of clinical response and outcomes with enzalutamide in noncastrated men with prostate cancer.

Commentary on: "Randomized phase III trial of temsirolimus and bevacizumab versus interferon alfa and bevacizumab in metastatic renal cell carcinoma: INTORACT trial." Rini BI, Bellmunt J, Clancy J, Wang K, Niethammer AG, Hariharan S, Escudier B. Brian I. Rini, Cleveland Clinic Taussig Cancer Institute, Cleveland, OH; Joaquim Bellmunt, University Hospital del Mar-IMIM, Barcelona, Spain; Jill Clancy, Kongming Wang, Andreas G. Niethammer, Subramanian Hariharan, Pfizer, New York, NY; and Bernard Escudier, Institut Gustave Roussy, Villejuif, France.: J Clin Oncol. 2014 Mar 10;32(8):752-9; doi: 10.1200/JCO.2013.50.5305. [Epub 2013 Dec 2]

PURPOSE

To prospectively determine the efficacy of combination therapy with temsirolimus plus bevacizumab versus interferon alfa (IFN) plus bevacizumab in metastatic renal cell carcinoma (mRCC).

PATIENTS AND METHODS

In a randomized, open-label, multicenter, phase III study, patients with previously untreated predominantly clear cell mRCC were randomly assigned, stratified by prior nephrectomy and Memorial Sloan-Kettering Cancer Center prognostic group, to receive the combination of either temsirolimus (25mg intravenously, weekly) or IFN (9MIU subcutaneously thrice weekly) with bevacizumab (10mg/kg intravenously, every 2weeks). The primary end point was independently assessed progression-free survival (PFS).

RESULTS

Median PFS in patients treated with temsirolimus/bevacizumab (n = 400) versus IFN/bevacizumab (n = 391) was 9.1 and 9.3 months, respectively (hazard ratio [HR] = 1.1; 95% CI: 0.9 to 1.3; P = .8). There were no significant differences in overall survival (25.8 ν 25.5 months; HR = 1.0; P = .6) or objective response rate (27.0% ν 27.4%) with temsirolimus/bevacizumab versus IFN/bevacizumab, respectively. Patients receiving temsirolimus/bevacizumab reported significantly higher overall mean scores in the Functional Assessment of Cancer Therapy-Kidney Symptom Index (FKSI)-15 and FKSI Disease-Related Symptoms subscale compared with IFN/bevacizumab (indicating improvement); however, no differences in global health outcome measures were observed. Treatment-emergent all-causality grade≥3 adverse events more common (P<.001) with temsirolimus/bevacizumab were mucosal inflammation, stomatitis, hypophosphatemia, hyperglycemia, and hypercholesterolemia, whereas neutropenia was more common with IFN/bevacizumab. Incidence of pneumonitis with temsirolimus/bevacizumab was 4.8%, mostly grade 1 or 2.

CONCLUSION

Temsirolimus/bevacizumab combination therapy was not superior to IFN/bevacizumab for first-line treatment in clear-cell mRCC.

Commentary on: "Ipilimumab versus placebo after radiotherapy in patients with metastatic castration-resistant prostate cancer that had progressed after docetaxel chemotherapy (CA184-043): A multicentre, randomised, double-blind, phase 3 trial." Kwon ED, Drake CG, Scher HI, Fizazi K, Bossi A, van den Eertwegh AJ, Krainer M, Houede N, Santos R, Mahammedi H, Ng S, Maio M, Franke FA, Sundar S, Agarwal N, Bergman AM, Ciuleanu TE, Korbenfeld E, Sengeløv L, Hansen S, Logothetis C, Beer TM, McHenry MB, Gagnier P, Liu D, Gerritsen WR, CA184-043 Investigators. Departments of Urology and Immunology and Mayo Clinic Comprehensive Cancer Center, Mayo Clinic, Rochester, MN, USA, Electronic address: kwon.eugene@mayo.edu; Johns Hopkins Sidney Kimmel Comprehensive Cancer Center and Brady Urological Institute, Baltimore, MD, USA; Memorial Sloan Kettering Cancer Center and Weill Cornell Medical College, New York, NY, USA; Institut Gustave Roussy, University of Paris-Sud, Villejuif, France; Institut Gustave Roussy, Villejuif, France; VU University Medical Centre, Amsterdam, Netherlands; Vienna General Hospital, Medical University Vienna, Vienna, Austria; Institut Bergonié, Bordeaux, France; CHU Caremeau, Nimes, France; Centro Médico Austral, Buenos Aires, Argentina; Centre Jean Perrin, Clermont-Ferrand, France; St John of God Hospital, Subiaco, WA, Australia; University Hospital of Siena, Istituto Toscano Tumori, Siena, Italy; Hospital de Caridade de Ijuí, Ijuí, Brazil; Nottingham University Hospital, Nottingham, UK; Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA; Netherlands Cancer Institute and Antoni van Leeuwenhoek Hospital, Amsterdam, Netherlands; Institute of Oncology Ion Chiricuta and University of Medicine and Pharmacy Iuliu Hatieganu, Cluj-Napoca, Romania; Hospital Británico de Buenos Aires, Buenos Aires, Argentina; Herlev Hospital, Herlev, Denmark; Odense University Hospital, Odense, Denmark; University of Texas MD Anderson Cancer Center, Houston,

BACKGROUND

Ipilimumab is a fully human monoclonal antibody that binds cytotoxic T-lymphocyte antigen 4 to enhance antitumour immunity. Our aim was to assess the use of ipilimumab after radiotherapy in patients with metastatic castration-resistant prostate cancer that progressed after docetaxel chemotherapy.

METHODS

We did a multicentre, randomised, double-blind, phase 3 trial in which men with at least one bone metastasis from castration-resistant prostate cancer that had progressed after docetaxel treatment were randomly assigned in a 1:1 ratio to receive bone-directed radiotherapy (8Gy in one fraction) followed by either ipilimumab 10mg/kg or placebo every 3 weeks for up to four doses. Non-progressing patients could continue to receive ipilimumab at 10mg/kg or placebo as maintenance therapy every 3 months until disease progression, unacceptable toxic effect, or death. Patients were randomly assigned to either treatment group via a minimisation algorithm, and stratified by Eastern Cooperative Oncology Group performance status, alkaline phosphatase concentration, haemoglobin concentration, and investigator site. Patients and investigators were masked to treatment allocation. The primary endpoint was overall survival, assessed in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT00861614.

FINDINGS

From May 26, 2009, to Feb 15, 2012, 799 patients were randomly assigned (399 to ipilimumab and 400 to placebo), all of whom were included in the intention-to-treat analysis. Median overall survival was 11.2 months (95% CI: 9.5-12.7) with ipilimumab and 10.0 months (8.3-11.0) with placebo (hazard ratio [HR] = 0.85, 0.72-1.00; P = 0.053). However, the assessment of the proportional hazards assumption showed that it was violated (P = 0.0031). A piecewise hazard model showed that the HR changed over time: the HR for 0-5 months was 1.46 (95% CI: 1.10-1.95), for 5-12 months was 0.65 (0.50-0.85), and beyond 12 months was 0.60 (0.43-0.86). The most common grade 3-4 adverse events were immune-related, occurring in 101 (26%) patients in the ipilimumab group and 11 (3%) of patients in the placebo group. The most frequent grade 3-4 adverse events included diarrhoea (64 [16%] of 393 patients in the ipilimumab group vs seven [2%] of 396 in the placebo group), fatigue (40 [11%] vs 35 [9%]), anaemia (40 [10%] vs 43 [11%]), and colitis (18 [5%] vs 0). Four (1%) deaths occurred because of toxic effects of the study drug, all in the ipilimumab group.

INTERPRETATION

Although there was no significant difference between the ipilimumab group and the placebo group in terms of overall survival in the primary analysis, there were signs of activity with the drug that warrant further investigation.

FUNDING

Bristol-Myers Squibb.

Abstract B07: Ratio of plasma 1,25(OH)2D to 25(OH)D is inversely associated with aggressive prostate cancer in African Americans in the North Carolina-Louisiana Prostate Cancer Project (PCaP)

Introduction: Epidemiologic studies have reported conflicting results when examining the relationship between circulating vitamin D metabolites and risk of advanced prostate cancer. While 25-hydroxy vitamin D [25(OH)D] is used as a measure of vitamin D status, 1,25-dihydroxy vitamin D [1,25(OH)2D] is the biologically active form and its concentration is tightly regulated. We previously reported increased odds of aggressive prostate cancer among African Americans in the highest tertile of plasma 25(OH)D compared to the lowest, and have now examined plasma 1,25(OH)2D and the ratio of 1,25(OH)2D to 25(OH)D in relation to prostate cancer aggressiveness.

Methods: Plasma 1,25(OH)2D and 25(OH)D were measured using LC/MS/MS in 435 African-American and 563 European-American men with newly-diagnosed prostate cancer from the North Carolina-Louisiana Prostate Cancer Project (PCaP). Men were classified as highly aggressive cases at time of diagnosis if Gleason sum ≥8, or PSA &gt;20 ng/ml, or Gleason sum ≥7 AND clinical stage = T3-T4, or Gleason sum=7 with a pattern of (4+3). The comparison group (low aggressiveness) included men with Gleason sum &lt;7 AND Stage T1-T2 AND PSA &lt; 9 ng/ml. Plasma 1,25(OH)2D and the ratio of plasma 1,25(OH)2D to 25(OH)D were categorized into tertiles and quartiles, respectively, based on distributions among low aggressive research subjects in each race separately. Odds ratios (OR) and 95% confidence intervals (95%CI) were calculated for high aggressive prostate cancer by tertiles of 1,25(OH)2D or quartiles of the 1,25(OH)2D:25(OH)D ratio using logistic regression with adjustment for potential confounders.

Results: Plasma 1,25(OH)2D was not associated with odds of aggressive prostate cancer in either African Americans or European Americans in this study (OR=0.83, 95%CI=0.49, 1.41 and OR=0.67, 95%CI=0.40, 1.11, respectively, for highest tertile compared to lowest tertile). However, higher quartiles (as compared to the lowest quartile) of 1,25(OH)2D:25(OH)D ratio were associated with reduced odds of high aggressive disease among African Americans after adjustment for age, season, education, alcohol intake, smoking status, PSA screening history, physical activity, energy intake, use of non-steroidal anti-inflammatory drugs, study site and body mass index (OR=0.51, 95%CI=0.28, 0.91; OR=0.41, 95%CI=0.22, 0.76, and OR=0.46, 95%CI=0.25, 0.84 for 2nd, 3rd and 4th quartiles, respectively). Inverse associations were also observed for European Americans, but were not statistically significant (OR=0.64, 95%CI=0.35, 1.17 for 4th compared to 1st quartile).

Conclusions: The ratio of plasma 1,25(OH)2D to 25(OH)D was inversely associated with prostate cancer aggressiveness among African Americans. Blood samples were collected after diagnosis, thus, it is possible that effects of treatment or extent of disease or associated processes (e.g., weight loss) on plasma vitamin D metabolites may have affected their measurement. Future analyses in PCaP will include examining circulating parathyroid hormone, calcium and phosphorus, as well as genotyping of genes encoding enzymes involved in the vitamin D metabolism and activity, which may help to explain these findings.

Citation Format: Susan E. Steck, Anna Woloszynska-Read, Lenore Arab, Daria McMahon, Jeannette Bensen, John S. Adams, Elizabeth T.H. Fontham, James L. Mohler, L. Joseph Su, Hongmei Zhang, Donald Trump, Candace Johnson. Ratio of plasma 1,25(OH)2D to 25(OH)D is inversely associated with aggressive prostate cancer in African Americans in the North Carolina-Louisiana Prostate Cancer Project (PCaP). [abstract]. In: Proceedings of the Sixth AACR Conference: The Science of Cancer Health Disparities; Dec 6–9, 2013; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2014;23(11 Suppl):Abstract nr B07. doi:10.1158/1538-7755.DISP13-B07

Abstract 4946: Developing anti-angiogenic therapies for human hepatocellular cancer (HCC)- studies of suntinib in the woodchuck model of hepatitis B related HCC

Introduction: Better animal models that recapitulate the liver milieu of human HCC are needed. The eastern woodchuck is an established model of human hepatitis B viral infection and spontaneously develops HCC in the context of chronic woodchuck hepatitis viral infection (WHV). The translational relevance of this model for developing anti-angiogenic therapies was evaluated using sunitinib (S), a potent oral, anti-angiogenic agent.

Methods: Woodchucks were bred and inoculated at birth with titered infectious WHV pools obtained from chronic WHV carriers. By 12 months of age, the rate of chronic WHV infection was &gt;60%. Carriers were followed by USG, upon developing HCC, 12 animals were randomized 1:1 to S or placebo (P) given once orally daily for 30 days. From a single treatment S PK study at 4 dose levels, n=3/group, simulations showed 12mg/kg daily was expected to be optimal for achieving steady state serum concentrations between 50- 100 ng/ml in woodchucks. Tumor size and blood flow were assessed using dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) before treatment and on day 28 using standardized protocols. At study completion or when animals were humanely euthanized, tumors and any other small nodules were fixed overnight in 10% buffered formalin. After standard processing and embedding in paraffin, 4 μm sections were prepared, deparaffinized, stained with hematoxylin-eosin (H&E), studied with a Zeiss Axio Imager A1 microscope by a pathologist blinded to the treatment arm. Morphometric study of areas of necrosis were compared to the size of the tumor sections by counting view fields at medium objective magnification, and differences in percentages between the groups were compared by the Excel student's two tailed, two-sample unequal variance t-test.

Results: The median age was 30 months. Four animals died during the course of the study (1P, 3 S) and were replaced. Median therapy duration was 28 days. Morphologically, portal hepatitis and pre-neoplastic lesions (foci of altered hepatocytes [FAH]) and larger areas of altered hepatocytes (AAH) were seen in all livers. Areas of tumor necrosis of varying size (20-100%) adjacent to terminal hepatic venules seen in both high grade and in rare, low grade tumor sections of S treated woodchucks were rare in P animals. The difference was highly significant (p= 6.0 E-13) between the two groups. By DCE-MRI, median tumor volume change was + 17% and -13% and necrotic tumor volume change was +22% and +190% in P and S treated animals respectively. However all MRI parameters (k trans, AUC90, median tumor volume) were not statistically significantly different between the groups.

Conclusions: Angiogenic response across different stages of hepatocarcinogenesis can be studied in woodchucks. Histological necrosis in S treated woodchucks without significant DCE-MRI change and the toxicities seen with S have translational significance to human HCC.

Citation Format: Alexander Pomakov, Ilia Toshkov, Sandra Buitrago, Leslie Curtin, Donald Trump, Candace Johnson, Edward Ashton, Bud Tennant, Renuka Iyer. Developing anti-angiogenic therapies for human hepatocellular cancer (HCC)- studies of suntinib in the woodchuck model of hepatitis B related HCC. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4946. doi:10.1158/1538-7445.AM2014-4946

Abstract 2226: Loss of STAG2 in bladder cancer

Bladder cancer (BC), 90% of which have transitional cell histology, is the fourth most common malignancy in the US. Transitional cell carcinoma (TCC), which occurs predominantly in men and whose incidence appears to be increasing, occurs most frequently as superficial disease which, while prone to recurrence, is not life threatening. However, TCC which invades the muscle layer of the bladder (stage T2-T4) is lethal in ∼50% of individuals. Stage T2-T4 TCC is present at initial diagnosis in ∼30% of patients and superficial TCC progresses to T2-T4 disease 20% of the time. We sequenced whole exomes of 28 muscle-invasive bladder tumors and performed an additional screen of over 200 genes in 119 additional TCCs. We found frequent alterations (10%) in STAG2, a gene encoding a subunit of the cohesin complex, which regulates the sister chromatids segregation process. Most mutations identified on STAG2 were nonsense, missense or frameshift. Genetic disruption of the sister chromatid segregation process leads to aneuploidy, which is one of the hallmarks of cancer. Based on recently published studies, however, it is uncertain whether a loss of STAG2 causes aneuploidy or not. In this study we sought to elucidate the role of STAG2 loss of expression in bladder tumorigenesis. We have analyzed the expression of STAG2 in 14 urothelial cell lines at both mRNA and protein levels by means of q-PCR and western blots, respectively. We found that STAG2 expression was lost in 2 of the 14 urothelial cell lines (HB-CLS-2 and UM-UC-3) analyzed. We chose SV-HUC (immortalized normal urothelium cells) along with two bladder cancer cell lines that had high expression of STAG2 (HB-CLS-1 and TCC-SUP) to study effects of STAG2 loss by transient knockdown. Knockdown of STAG2 in SV-HUC, TCC-SUP and HB-CLS-1 cells did not affect proliferation. Cell cycle analysis on TCC-SUP cells revealed that STAG2 knockdown resulted in a lower percentage of cells in the G0/G1 phase in comparison to the scrambled control. Taken together, these data suggest that STAG2 has a role in modifying DNA content but not proliferation. Our ongoing studies utilizing bladder cancer tissue microarray (TMAs) and copy number variation (CNV) array will help to clarify the consequences of STAG2 loss in bladder cancer.

Citation Format: Nithya Krishnan, Anna Woloszynska-Read, Jianmin Wang, Song Liu, Carl Morrison, Khurshid Guru, Evelyn Smit, Donald Trump, Candace Johnson. Loss of STAG2 in bladder cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2226. doi:10.1158/1538-7445.AM2014-2226

Abstract 178: Vitamin D reduces lung cancer progression the N-nitroso-tris-chloroethylurea model of mouse lung squamous cell carcinoma

Vitamin D, an essential mediator of calcium homeostasis, acts through the vitamin D receptor to promote cellular differentiation and inhibit proliferation. Epidemiologic studies indicate that low serum levels of 25(OH)D3 are associated with increased risk and poor prognosis of lung cancer. Pre-clinical studies in mice show that dietary vitamin D and calcium deficiency promote carcinogenesis in mouse models of cancer. These data suggest that vitamin D may have a role as a chemopreventive agent. To investigate the role of vitamin D in lung cancer, a carcinogen-induced model of lung squamous cell carcinoma (SCC) was employed. N-nitroso-tris-chloroethylurea (NTCU) was applied topically each week to the back of SWR/J mice. Following ∼15 weeks of NTCU treatment, mice on a standard diet begin to develop flat atypia, which progresses through dysplasia to invasive lung SCC by 35 to 40 weeks.

We investigated the effects of vitamin D on cancer progression using different levels of dietary vitamin D3 and injections of the most active metabolite 1,25(OH)2D3 (calcitriol) in the NTCU model (80 mM/week). After 24 weeks of NTCU, mice on a deficient diet had more advanced disease than those on a sufficient diet. However, that study demonstrated that the 80 mM/week of NTCU was too toxic and resulted in premature death. A second vitamin D intervention study has now been completed using a less toxic dose of 40 mM/week of NTCU. In this study mice were randomized to 6 treatment groups (Table 1). Disease burden, as measured by histology (Table 1), was similar to that seen with higher dose NCTU. This study supports our earlier findings that vitamin D deficient mice develop disease at a more rapid rate when compared to mice that are sufficient. This also suggests that calcitriol administration may reduce the progression of lung SCC in mice that are vitamin D deficient. Further studies are on going to elucidate the mechanism by which vitamin D acts to slow the progression of lung SCC in this model.

Table 1. Serum 25(OH)D3 levels & incidence of high-grade dysplasia and lung SCC. Group Carcinogen (NTCU) Diet Vitamin D (IU/kg) Serum 25(OH)D3 Level (ng/ml) High-grade Dysplasia (%) Lung SCC (%) D deficient − 0 &lt;4 0/11 (0) 0/11 (0) D deficient +NTCU + 0 &lt;4 13/13 (100) 11/13 (85) D deficient +NTCU & calcitriol (i.p. 80 ug/kg/w) + 0 &lt;4 14/14 (100) 8/14 (57) D sufficient − 2,000 21 0/14 (0) 0/14 (0) D sufficient +NTCU + 2,000 19 13/14 (92) 4/14 (29) D sufficient +NTCU & calcitriol (i.p. 80 ug/kg/w) + 2,000 10 10/13 (76) 3/13 (20)

Citation Format: Sarah A. Mazzilli, Mary Reid, Paul Bogner, Donald Trump, Candace Johnson. Vitamin D reduces lung cancer progression the N-nitroso-tris-chloroethylurea model of mouse lung squamous cell carcinoma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 178. doi:10.1158/1538-7445.AM2013-178

X-linked retinoschisis maculopathy treated with topical dorzolamide, and relationship to genotype

PURPOSE

To correlate the response of topical dorzolamide (Trusopt; Merck) in patients with X-linked retinoschisis (XLRS) with genotype.

METHODS

We carried out a retrospective evaluation of four patients (seven eyes) with XLRS, treated with topical dorzolamide. The change in best-corrected visual acuity (VA) and central macular thickness (CMT; central 1 mm subfield thickness) from optical coherence tomography (OCT) was analysed over the follow-up period, using Student's t-test. Each patient also had genetic analysis for mutations in the retinoschisisgene (RS1).

RESULTS

The mean age at the start of treatment was 14.7±11 years, and mean follow-up duration was 21.7±7.7 months. Mean CMT at the final follow-up was significantly better than at baseline (291±123 vs 352±119 μm, P=0.007); however, mean VA was worse (0.38±0.25 vs 0.31±0.24 logMAR score, P=0.041). All four patients had a mutation in the RS1gene; there was no apparent association between the type of mutation and the response to topical dorzolamide.

CONCLUSION

Topical dorzolamide may have some effect in reducing central macular thickness in patients with XLRS, but this does not necessarily correlate with improvement in VA. In our case series, genotypic information did not predict the response to this treatment.

Abstract 942: Protein kinase CK2 contributes to 1, 25-dihydroxyvitamin D3-mediated CYP24A1 gene expression in prostate cancer cells

The active vitamin D metabolite 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) plays a major role in regulating calcium homeostasis and bone mineralization. 1,25(OH)2D3 also modulates cellular proliferation and differentiation in a variety of cell types through the activation of vitamin D receptor (VDR), by both genomic and nongenomic pathways. 1,25-(OH)2D3 has anti-tumor effects in several tumor models. 24-hydroxylase, encoded by the CYP24A1 gene, plays a key role in degrading 1,25(OH)2D3. Suppression of CYP24A1 function enhances the antitumor activity of vitamin D. In order to isolate regulators of CYP24A1 expression in prostate cancer cells, we established the prostate cancer cell line PC3 stably transfected with CYP24A1 promoter driving luciferase expression and used this cell line to screen for compounds that inhibit CYP24A1 promoter activity, using a drug library. From this screening, we identified, 4,5,6,7-tetrabromobenzimidazole (TBBz), a protein kinase CK2 selective inhibitor as a disruptor of CYP24A1 promoter activity. We show that TBBz specifically inhibits CYP24A1 promoter activity induced by 1,25(OH)2D3 in prostate cancer DU145 and PC3 cells. In addition, TBBz downregulates endogenous CYP24A1 mRNA level in TBBz treated PC3 cells. Furthermore, siRNA-mediated CK2 knockdown reduces 1,25(OH)2D3 induced CYP24A1 mRNA expression in PC3 cells. This inhibitory effect on CYP24A1 expression by CK2 siRNA is enhanced by the addition of TBBz. These results suggest that CK2 signaling contributes to 1,25(OH)2D3 mediated induction of CYP24A expression. This study provides among the first line of evidence that CK2 is linked to vitamin D metabolism. Future studies will elucidate the mechanism(s) underlying the mechanism by which CK2 regulates CYP24A1 expression. In summary, our findings reveal that protein kinase CK2 is involved in the regulation of CYP24A1 expression by 1,25(OH)2D3, and highlight a novel strategy to facilitate the optimization of antitumor therapy of vitamin D.

This study was supported by NIH/NCI grants 5R01CA067267 and 5R01CA095045

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 942. doi:10.1158/1538-7445.AM2011-942

Effect of 25-hydroxyvitamin D status on serological response to influenza vaccine in prostate cancer patients

BACKGROUND

Epidemiologic data suggest that there is an association between vitamin D deficiency and influenza infection. We conducted a prospective influenza vaccination study to determine the influence of vitamin D status on serological response to influenza vaccine in prostate cancer (CaP) patients.

METHODS

During the 2006-2007 influenza season, CaP patients treated at Roswell Park Cancer Institute were offered vaccination with the trivalent influenza vaccine (Fluzone®, 2006-2007) and sera collected for hemagglutination inhibition (HI) assay titers before and 3 months after vaccination. Response to vaccination was defined as ≥1:40 titer ratio or a fourfold increase in titer at 3 months, against any of the three strains. Serum 25-hydroxyvitamin D (25-D₃) levels were measured using DiaSorin ¹²⁵I radioimmunoassay kits.

RESULTS

Thirty-five patients with CaP participated in the study. Median baseline 25-D₃ level was 44.88 ng/ml (range: 9.16-71.98 ng/ml) Serological response against any of the three strains was noted in 80%. There was a significant effect of baseline 25-D3 level when tested as a continuous variable in relation to serological response (P = 0.0446). All patients in the upper quartile of 25-D3 level responded by mounting a serological response (P = 0.0344). None of the other baseline variables (age, race, chemotherapy status, or white cell count) had an effect on serological response.

CONCLUSIONS

In this study in CaP patients, a replete vitamin D status was associated with more frequent serological response to influenza vaccine.

Rates of loss of heterozygosity and mitotic recombination in NF2 schwannomas, sporadic vestibular schwannomas and schwannomatosis schwannomas

Biallelic inactivation of the NF2 gene occurs in the majority of schwannomas. This usually involves a combination of a point mutation or multiexon deletion, in conjunction with either a second point mutation or loss of heterozygosity (LOH). We have performed DNA sequence and dosage analysis of the NF2 gene in a panel of 239 schwannoma tumours: 97 neurofibromatosis type 2 (NF2)-related schwannomas, 104 sporadic vestibular schwannomas (VS) and 38 schwannomatosis-related schwannomas. In total, we identified germline NF2 mutations in 86 out of 97 (89%) NF2 patients and a second mutational event in 77 out of 97 (79%). LOH was by far the most common form of second hit. A combination of microsatellite analysis with either conventional comparative genomic hybridization (CGH) or multiplex ligation-dependent probe amplification (MLPA) identified mitotic recombination (MR) as the cause of LOH in 14 out of 72 (19%) total evaluable tumours. Among sporadic VS, at least one NF2 mutation was identified by sequence analysis or MLPA in 65 out of 98 (66%) tumours. LOH occurred in 54 out of 96 (56%) evaluable tumours, but MR only accounted for 5 out of 77 (6%) tested. LOH was present in 28 out of 34 (82%) schwannomatosis-related schwannomas. In all eight patients who had previously tested positive for a germline SMARCB1 mutation, this involved loss of the whole, or part of the long arm, of chromosome 22. In contrast, 5 out of 22 (23%) tumours from patients with no germline SMARCB1 mutation exhibited MR. High-resolution Affymetrix SNP6 genotyping and copy number (CN) analysis (Affymetrix, Santa Clara, CA, USA) were used to determine the chromosomal breakpoint locations in tumours with MR. A range of unique recombination sites, spanning approximately 11.4 Mb, were identified. This study shows that MR is a mechanism of LOH in NF2 and SMARCB1-negative schwannomatosis-related schwannomas, occurring less frequently in sporadic VS. We found no evidence of MR in SMARCB1-positive schwannomatosis, suggesting that susceptibility to MR varies according to the disease context.

SMARCB1 mutations are not a common cause of multiple meningiomas

BACKGROUND

Schwannomas and meningiomas are both part of the tumour spectrum of neurofibromatosis type 2 (NF2) and are associated with somatic loss of chromosome 22. They are also found commonly within the general population, unrelated to NF2. Germline SMARCB1 mutations have recently been identified as a pathogenic cause of a subset of familial schwannomatosis cases, and SMARCB1 is a candidate gene for causation of both schwannomas and meningiomas. Recently, Bacci et al reported a germline SMARCB1 mutation associated with familial schwannomatosis and multiple meningiomas. They concluded that SMARCB1 mutations can predispose to multiple meningiomas.

METHODS

We screened the SMARCB1 gene in a panel of 47 patients with multiple meningioma unrelated to NF2.

RESULTS

We found no germline mutations.

CONCLUSION

We conclude that while meningiomas may be associated with the schwannomatosis phenotype, SMARCB1 is not a major contributor to multiple meningioma disease.

Correlations between clinical and physiological consequences of the novel mutation R878C in a highly conserved pore residue in the cardiac Na+ channel

Aim:

We compared the clinical and physiological consequences of the novel mutation R878C in a highly conserved pore residue in domain II (S5-S6) of human, hNa_v1.5, cardiac Na⁺ channels.

Methods:

Full clinical evaluation of pedigree members through three generations of a Chinese family combined with SCN5A sequencing from genomic DNA was compared with patch and voltage-clamp results from two independent expression systems.

Results:

The four mutation carriers showed bradycardia, and slowed sino-atrial, atrioventricular and intraventricular conduction. Two also showed sick sinus syndrome; two had ST elevation in leads V1 and V2. Unlike WT-hNa_v1.5, whole-cell patch-clamped HEK293 cells expressing R878C-hNa_v1.5 showed no detectable Na⁺ currents (i_Na), even with substitution of a similarly charged lysine residue. Voltage-clamped Xenopus oocytes injected with either 0.04 or 1.5 μg μL⁻¹ R878C-hNa_v1.5 cRNA similarly showed no i_Na, yet WT-hNa_v1.5 cRNA diluted to 0.0004–0.0008 ng μL⁻¹resulted in expression of detectable i_Na. i_Na was simply determined by the amount of injected WT-hNa_v1.5: doubling the dose of WT-hNa_v1.5 cRNA doubled i_Na. i_Na amplitudes and activation and inactivation characteristics were similar irrespective of whether WT-hNa_v1.5 cRNA was given alone or combined with equal doses of R878C-hNa_v1.5 cRNA therefore excluding dominant negative phenotypic effects. Na⁺ channel function in HEK293 cells transfected with R878C-hNa_v1.5 was not restored by exposure to mexiletine (200 μm) and lidocaine (100 μm). Fluorescence confocal microscopy using E3-Nav1.5 antibody demonstrated persistent membrane expression of both WT and R878C-hNa_v1.5. Modelling studies confirmed that such i_Na reductions reproduced the SSS phenotype.

Conclusion:

Clinical consequences of the novel R878C mutation correlate with results of physiological studies.

Molecular characterisation of SMARCB1 and NF2 in familial and sporadic schwannomatosis

BACKGROUND

Schwannomatosis is a rare condition characterised by multiple schwannomas and lack of involvement of the vestibular nerve. A recent report identified bi-allelic mutations in the SMARCB1/INI1 gene in a single family with schwannomatosis. We aimed to establish the contribution of the SMARCB1 and the NF2 genes to sporadic and familial schwannomatosis in our cohort.

METHODS

We performed DNA sequence and dosage analysis of SMARCB1 and NF2 in 28 sporadic cases and 15 families with schwannomatosis.

RESULTS

We identified germline mutations in SMARCB1 in 5 of 15 (33.3%) families with schwannomatosis and 2 of 28 (7.1%) individuals with sporadic schwannomatosis. In all individuals with a germline mutation in SMARCB1 in whom tumour tissue was available, we detected a second hit with loss of SMARCB1. In addition, in all affected individuals with SMARCB1 mutations and available tumour tissue, we detected bi-allelic somatic inactivation of the NF2 gene. SMARCB1 mutations were associated with a higher number of spinal tumours in patients with a positive family history (p = 0.004).

CONCLUSION

In contrast to the recent report where no NF2 mutations were identified in a schwannomatosis family with SMARCB1 mutations, in our cohort, a four hit model with mutations in both SMARCB1 and NF2 define a subset of patients with schwannomatosis.

Randomized trial of toremifene to reduce high grade prostatic intraepithelial neoplasia (HGPIN) prior to radical prostatectomy (RP)

5150

Background HGPIN may be a precursor lesion for prostate cancer (PCA). The selective estrogen-receptor modulator toremifene (TOR) has shown chemopreventive activity in preclinical models of PCA. The effect of TOR on HGPIN was studied in men with PCA prior to RP. Methods Men with biopsy-proven PCA, scheduled for RP were randomized (2:1) either to TOR 40 mg po qd for 3 to 6 weeks prior to RP or to no therapy. The primary endpoint was the proportion of HGPIN in the RP specimen. Planned sample sizes were 35 and 17 per arm respectively, providing 93% power if treatment increased the proportion of patients with no RP HGPIN from 15% to 35% and decreased the mean log nonzero HGPIN values from 1 to ¼ standard deviation. Expression of bcl2, ki67, and CD31 were determined on biopsy (BX), and RP tissues, separately for normal adjacent to tumor (NAT), HGPIN, and PCA tissues. Serum hormone levels and toxicity were also assessed. Results The treatment arm accrued 31 patients, the control arm 13 patients. RP HGPIN ranged from 0.5% to 12%. There was no difference in HGPIN means between treatment (3.8%) and control (3.3%) (P=0.77 one-sided Wilcoxon) HGPIN at baseline predicted HGPIN at RP (Spearman correlation=0.64, P=0.0005) but 66% of patients had no detected HGPIN at baseline. Bcl2, ki67, and CD31 were mutually positively correlated in all 3 tissues, in both BX and RP specimens. In both BX and RP specimens, bcl2 was highest by far in HGPIN, and lowest in PCA. Ki67 was lowest in NAT, elevated in HGPIN and highest in PCA. CD31 showed no differences. In treated patients but not in controls, dihydrotestosterone, testosterone, androstenedion, and estradiol increased significantly between baseline, day 14 and final. TOR was well tolerated. Conclusions These data do not support an effect of TOR on HGPIN over 3 to 6 weeks at 40 mg po qd.

No significant financial relationships to disclose.

Can 1H-Nuclear magnetic resonance (NMR) be used for early detection of hepatocellular cancer (HCC)?

15107

Background: HCC is a common and rapidly fatal cancer. Current screening tools are inadequate for identification of potentially curable cases. Our aim was to determine whether H-NMR can identify HCC compared to controls in the woodchuck (WC) model of hepatitis related HCC. Methods: Eastern WCs were bred and inoculated at birth with dilute sera from WCs that are chronic carriers of Woodchuck Hepatitis B Virus (WHV). This resulted in chronic hepatitis in ∼60% animals and all carriers developed HCC by 24–36 months. Serum from 10 chronic WHV carriers with HCC (group 1), 5 WHV carriers with no HCC (group 2) and 15 matched non-infected controls (group 3) was obtained. 45uL serum was diluted with 5uL of D2O containing 27mM formic acid + 0.9% saline. Spectra were collected on a 600 MHz INOVA spectrometer using a CapNMR flow probe with 10uL flow cell at 298K without knowledge of group assignments. The resulting 1D spectra were processed using Nuts from AcornNMR. Results: Principle component analysis and supervised PLS-DA was performed using Simca P+ from Umetrics. Despite general separation of groups, the Q2 value of this model was relatively low (0.20). We trained a Support Vector Machine (SVM) algorithm, a supervised machine-learning algorithm, to learn to identify the groups. Evaluation of the performance of the algorithm using 10-fold validation on the data set achieved a Kappa value of 0.43. This algorithm learnt to identify HCC [0.765 ROC, 0.8 sensitivity, and 0.727 positive predictive value (PPV)] and controls (0.75 ROC, 0.69 sensitivity and 0.73 PPV) but not the WHV carrier group, likely due to the small numbers. In a second analysis of 10 HCC and 15 controls, PLS-DA showed clear separation using three components (Q2= 0.5). The corresponding SVM model showed a kappa value of 0.52 and ROC values of 0.767 for both classes. Conclusions: Our preliminary results indicate that H-NMR spectra alone can be used to distinguish HCC from healthy controls using the machine-learning algorithm for classification. Further validation in a larger cohort of woodchucks is ongoing and confirmation of these preliminary findings would support investigation of this technique as a screening tool in patients at risk for developing HCC.

No significant financial relationships to disclose.

Inherited association of breast and colorectal cancer: limited role of CHEK2 compared with high-penetrance genes

We assessed the association between breast cancer (BC) and colorectal cancer (CRC) from referral pattern to the Regional Genetics Service including molecular analysis. Hospital computer records and/or department referral books were used to identify cases referred to the Regional Genetic Service during a 16-year period (1990-2005 inclusive). All files were reviewed along with associated demographic data, risk assessments, referral details and results from mutation testing. Families were assessed for hereditary breast and colorectal cancer (HBCC) criteria, and all families with eligible individuals were tested for the 1100delC mutation in CHEK2. A total of 8,612 families were identified. One hundred and sixteen of 1,631 (7.5%) families with a primary referral for CRC fulfilled the criteria for HBCC, whereas only 68/6981 (1%) BC referrals fulfilled these criteria. Blood samples were obtained from 113 individuals from 83/184 families. Only 1/113 (1%) has screened positive for the CHEK2 mutation, whereas 14 (17%) families segregate BRCA1/2 mutations and at least 7 (8.5%) carry MLH1/MSH2 mutations. HBCC syndrome, if it exists as a separate entity, is not likely to be due to CHEK2 mutations. Many families are explicable by existing high-penetrance genes, and further work is necessary to elucidate whether the remainder is due to chance or as yet undiscovered genes.

A phase I study of vorinostat (suberoylanilide hydroxamic acid, SAHA) in combination with 5-fluorouracil, leucovorin, and oxaliplatin (FOLFOX) in patients with advanced colorectal cancer (CRC)

3592

Background: Vorinostat is a novel histone deacetylase (HDAC) inhibitor that potentiates 5-FU and platinum antitumor activity. This potentiation is associated with ∼ 40 fold decrease in thymidilate synthase (TS) expression, the main target of 5-FU, in preclinical models. We conducted a phase I study of vorinostat plus FOLFOX in patients with CRC to determine the recommended dose of this combination. Methods: Vorinostat was escalated in a standard 3+3 design. FOLFOX was administered at a fixed dose every 2 weeks: leucovorin 400mg/m2 and oxaliplatin 85mg/m2 over 2 hours followed by 5-FU bolus 400mg/m2 and 5-FU infusion 2400mg/m2 over 46 hours. Vorinostat started 3 days prior to FOLFOX and was given twice daily for 1 week followed by 1 week break. Investigated dose levels of vorinostat (twice daily) include 100, 200, and 300 mg. Tumor biopsies were obtained from patients with accessible liver metastases before and on the 4th day of vorinostat (prior to FOLFOX) to assess TS expression. Results: 9 patients (pts) enrolled (M/F: 8/1; median age: 57, ECOG 0/1: 5/4). All pts had failed prior FOLFOX, irinotecan, and cetuximab therapy. One pt at dose level (DL) 1 was not evaluable due to rapid clinical progression. No dose-limiting toxicities were noted among the 8 evaluable pts. No grade (G) 3 toxicities were noted on the first cycle of treatment (within 2 weeks after 1st FOLFOX) and accrual continues on DL3. Cycle 1 toxicities were attributed to FOLFOX and consisted of 1 G2 neutropenia, 1 G2 mucositis, and 2 G2 nausea/vomiting. Responses were evaluable in 6 pts: 1 pt with peritoneal carcinomatosis on DL 1 has stable disease 5 months + along with a stable CEA; 3 patients at DL2 have stable disease at 2 months along with declining CEA in 2/3 pts. Two pts (DL1) with liver metastases biopsies had a major decrease in TS expression by IHC after 4 days of vorinostat. Conclusions: Vorinostat at 100–200mg PO BID × 1 week every 2 weeks in combination with FOLFOX is well tolerated. The lowest DL of 100 mg PO BID is associated with down-regulation of TS. Disease stabilization in highly refractory patients is promising. The investigation of this regimen in the first or second-line treatment of metastatic CRC is warranted.

No significant financial relationships to disclose.

Phase I, pharmacokinetic (PK), pharmacodynamic study of paricalcitol [19-nor-1 alpha, 25-(OH)2 D2] in combination with gemcitabine [2’,2’ difluorodeoxycytidine] in patients with advanced malignancies

12010

Background: Calcitriol+ gemcitabine (gem) combination results in synergistic anti-tumor effect in preclinical models. Cytidine deaminase (CDD) inactivates gem into 2’,2’-difluorodeoxyuridine (dFdU) and its overexpression may lead to gem resistance. Calcitriol decreases CDD activity in peripheral blood mononuclear cells (PBM). Paricalcitol is cytotoxic in vitro and synergistic with several chemotherapeutic agents, including gem. We are conducting a phase I study of paricalcitol + fixed-dose gem. Objectives: The primary aim is to determine maximum tolerated dose (MTD) of the combination in patients (pts) with advanced cancer. Secondary aims are to evaluate toxicity, the effect of paricalcitol on gem PK, CDD activity in PBM and clinical outcome. Methods: Each cycle is 4 weeks: Gem 800 mg/m2 (over 80 min) weekly × 3, starting day 1; paricalcitol weekly, 24 h prior to gem, starting day 7. Standard 3+3 dose-escalation schema is used. Planned paricalcitol doses are 0.24, 0.72, 1.20, 1.8, 2.4 μg/kg, and 25% increments till MTD. Gem PK and CDD activity (PBM) are studied on days 1 and 8. Paricalcitol PK studies are obtained on day 7. Results: Fourteen pts with the following cancers: pancreatic (n=3), colon (n=3), lung (n=5), esophageal (n=1), bladder (n=1) and unknown primary (n=1) have been enrolled. No dose limiting toxicities have occurred. Median of 2 cycles were delivered (range 1–9). Grade 3 toxicities: anemia (n=3 pts), neutropenia (n=5), thrombocytopenia (n=3), thrombosis (n=2), anorexia (n=1), hypophosphatemia (n=1), dehydration (n=1), syncope (n=1), pneumonia (n=1) and chills (n=1). Grade 4 toxicities: anemia (n=1) and neutropenia (n=1). Hypercalcemia (> grade 1) did not occur. Stable disease occurred in 2 and progressive disease in 3. Conclusions: MTD was not reached at 1.8 μg/kg of paricalcitol with gem 800 mg/m2/week. Dose escalation is ongoing. PK data will be presented at meeting. Supported by NIH grants CA67267 and CA85142.

[Table: see text]

Immediate versus deferred androgen deprivation treatment in patients with node-positive prostate cancer after radical prostatectomy and pelvic lymphadenectomy

BACKGROUND

Appropriate timing of androgen deprivation treatment (ADT) for prostate cancer is controversial. Our aim was to determine whether immediate ADT extends survival in men with node-positive prostate cancer who have undergone radical prostatectomy and pelvic lymphadenectomy compared with those who received ADT only once disease progressed.

METHODS

Eligible patients from 36 institutes in the USA were randomly assigned in 1988-93 to receive immediate ADT (n=47) or to be observed (n=51), with ADT to be given on detection of distant metastases or symptomatic recurrences. Patients were followed up every 3 months for the first year and every 6 months thereafter. The primary endpoint was progression-free survival; secondary endpoints were overall and disease-specific survival. Analysis was by intention to treat. To ensure that the treatment groups were comparable, we did a retrospective central pathology review of slides and regraded the Gleason scores for available samples. This trial predates the requirement for clinical trial registration.

FINDINGS

At median follow-up of 11.9 years (range 9.7-14.5 for surviving patients), men assigned immediate ADT had a significant improvement in overall survival (hazard ratio 1.84 [95% CI 1.01-3.35], p=0.04), prostate-cancer-specific survival (4.09 [1.76-9.49], p=0.0004), and progression-free survival (3.42 [1.96-5.98], p<0.0001). Of 49 histopathology slides received (19 immediate ADT, 30 observation), 16 were downgraded from the original Gleason score (between groups < or = 6, 7, and > or = 8) and five were upgraded. We recorded similar proportions of score changes in each group (p=0.68), and no difference in score distribution by treatment (p=0.38). After adjustment for score, associations were still significant between treatment and survival (overall, p=0.02; disease-specific, p=0.002; progression-free survival, p<0.0001).

INTERPRETATION

Early ADT benefits patients with nodal metastases who have undergone prostatectomy and lymphadenectomy, compared with those who receive deferred treatment. The beneficial effects of early ADT, rather than an imbalance in risk factors, are likely to explain the differences in outcomes between treatments.

X-linked retinoschisis: clinical phenotype and RS1 genotype in 86 UK patients

BACKGROUND

Inactivating mutations of the gene RS1 lead to X-linked retinoschisis, a progressive retinal dystrophy characterised by schisis within the inner layers of the neuroretina. The mutation spectrum is large and the phenotype variable.

AIM

To determine whether there is a correlation between mutation type and disease severity.

METHODS

We identified the causative mutation in 86 affected patients and examined each of these patients in detail. Different categories of mutation were compared for each phenotypic characteristic.

RESULTS

We found a reduction in visual acuity with increasing age and worsening macular pathology in patients over 30 years old (p < or = 0.001), but there was no correlation between mutation type and severity of disease. Furthermore, we found a wide variation in phenotype even within families.

CONCLUSIONS

Identifying the causative mutation in patients with X-linked retinoschisis is helpful in confirming diagnosis and in counselling of family members but cannot be used to predict prognosis for an individual patient.

Is Optic Nerve Fibre Mis-Routing a Feature of Congenital Stationary Night Blindness?

PURPOSE

To determine whether patients with congenital stationary night blindness (CSNB) have electrophysiological evidence of optic nerve fibre mis-routing similar to that found in patients with ocular albinism (OA).

METHOD

We recorded the Pattern Onset VEP using a protocol optimised to detect mis-routing of optic nerve fibres in older children and adults. We tested 20 patients (age 15-69 yrs) with X-linked or autosomal recessive CSNB, 14 patients (age 9-56 yrs) with OA and 13 normally pigmented volunteers (age 21-66 yrs). We measured the amplitude and latency of the CI component at the occipital midline and over left and right occipital hemispheres. We also assessed the computed inter-hemispheric "difference" signal. Subjects with CSNB were classified as having the "complete" or "incomplete" phenotype on the basis of their ERG characteristics. Members of X-linked CSNB pedigrees underwent mutation screening of the NYX and CACNA1F genes.

RESULTS

CI was significantly smaller over the ipsilateral hemisphere and more prominent over the contralateral hemisphere in OA patients compared with both controls and CSNB patients. In CSNB patients CI response amplitudes were not significantly different from controls but peak latency was prolonged at all three electrodes compared with controls. The inter-hemispheric "difference" signal was abnormal for the OA group but not for the CSNB group. Contralateral dominance of CI could be identified in the majority of OA patients and the "difference" signal was opposite in polarity for left compared with right eye stimulation in every patient in this group. Only 3 of 20 patients with CSNB showed significant inter-hemispheric asymmetry similar to that seen in the OA patients. All 3 CSNB patients with evidence for optic nerve fibre mis-routing had X-linked pedigrees: 2 had an identified mutation in the NYX gene but no mutation in either the NYX or CACNA1F genes was identified in the third. VEP evidence of optic nerve fibre mis-routing was present in 3 of the 11 subjects with "complete" phenotype and none of the 9 patients with "incomplete" phenotype CSNB.

CONCLUSION

Mis-routing of optic nerve fibres does occur in CSNB but we found evidence of it in only 15% of our patients.

Molecular pathology of X linked retinoschisis: mutations interfere with retinoschisin secretion and oligomerisation

BACKGROUND/AIM

X linked retinoschisis (XLRS) is caused by mutations in RS1 which encodes the discoidin domain protein retinoschisin, secreted by photoreceptors and bipolar cells. Missense mutations occur throughout the gene and some of these are known to interfere with protein secretion. This study was designed to investigate the functional consequences of missense mutations at different locations in retinoschisin.

METHODS AND RESULTS

The authors developed a structural model of the retinoschisin discoidin domain and used this to predict the effects of missense mutations. They expressed disease associated mutations and found that those affecting conserved residues prevented retinoschisin secretion. Most of the remaining mutations cluster within a series of loops on the surface of the beta barrel structure and do not interfere with secretion, suggesting this region may be a ligand binding site. They also demonstrated that wild type retinoschisin octamerises and associates with the cell surface. A subgroup of secreted mutations reduce oligomerisation (C59S, C219G, C223R).

CONCLUSIONS

It is suggested that there are three different molecular mechanisms which lead to XLRS: mutations interfering with secretion, mutations interfering with oligomerisation, and mutations that allow secretion and oligomerisation but interfere with retinoschisin function. The authors conclude that binding of oligomerised retinoschisin at the cell surface is important in its presumed role in cell adhesion.

Results from a pilot Phase I trial of gefitinib combined with docetaxel and estramustine in patients with hormone-refractory prostate cancer

BACKGROUND

Gefitinib, which is an orally active epidermal growth factor receptor tyrosine kinase inhibitor, has demonstrated activity against hormone-refractory prostate cancer (HRPC) in preclinical studies. In this pilot Phase I trial, the authors evaluated the tolerability, efficacy, and pharmacokinetics of gefitinib combined with estramustine and docetaxel in patients with HRPC.

METHODS

Patients received gefitinib (at a dose of 250 mg/day or 500 mg/day) on each day of a 21-day treatment cycle. Docetaxel (at a dose of 60 mg/m(2)) was administered on Day 1, and estramustine (at a dose of 280 mg) was administered 3 times daily on Days 1 through 5.

RESULTS

Fifteen patients were recruited at each gefitinib dose level. The most common adverse events observed were consistent with the known profiles of gefitinib, docetaxel, and estramustine. No dose-limiting toxicity was observed. Adverse events considered to be gefitinib related included diarrhea (n = 23 patients), rash (n = 8 patients), nausea (n = 7 patients), dry skin (n = 6 patients), and emesis (n = 6 patients). Overall, 9 of 22 evaluable patients (40.9%) experienced a pain response. and 9 of 30 patients (30%) had a prostate-specific antigen response. A partial objective tumor response was demonstrated in 1 of 13 evaluable patients (7.7%) in each dose group; the median time to progression for both doses combined was 185 days (range, 28-233 days). Data comparisons within individual patients suggested that docetaxel and estramustine had no effect on gefitinib steady-state levels. Gefitinib had no effect on docetaxel exposure at the 250-mg dose but decreased exposure at the 500-mg dose. However, gefitinib may increase exposure to estramustine, particularly at the 500 mg/day dose.

CONCLUSIONS

The results of the current study demonstrated that gefitinib combined with estramustine and docetaxel had acceptable and predictable tolerability. However, it is unclear whether gefitinib provides an additional clinical benefit over docetaxel and estramustine alone.

Identification of XLRS1 gene mutation (608C > T) in a Portuguese family with juvenile retinoschisis

PURPOSE

To characterize electroretinogram (ERG) and molecular genetic findings in a family with XLRS1 mutation. The authors present two cases of a Portuguese family with juvenile retinoschisis with a mutation in exon 6.

METHODS

Two brothers and their parents, grandmother, and uncle underwent a full ophthalmic examination. The two brothers with ophthalmic disease were evaluated with color fundus photography, fluorescein angiography, optical coherence tomography (OCT), molecular genetic study (Group VI of Retinoschisis Consortium), pattern visual evoked potential (PVEP), and full field ERG.

RESULTS

Both patients presented funduscopic manifestations of vitre o retinal degeneration. They presented peripheral schisis and retinal detachment. However, foveal schisis had never been observed at funduscopy. A negative ERG was recorded in both. Six months after that, the younger brother showed a typical foveal schisis at fundus examination. A retinoschisis gene (XLRS1) mutation with transition of cytosine by thymine at position 608 (608C > T) had been identified in both.

CONCLUSIONS

Negative ERG is the most secure clinical marker to establish the diagnosis of juvenile retinoschisis. XLRS1 gene 608C > T mutation was described for the first time in a Portuguese family.

Identification of XLRS1 gene mutation (608C>T) in a Portuguese family with juvenile retinoschisis

PURPOSE

To characterize electroretinogram (ERG) and molecular genetic findings in a family with XLRS1 mutation. The authors present two cases of a Portuguese family with juvenile retinoschisis with a mutation in exon 6.

METHODS

Two brothers and their parents, grandmother, and uncle underwent a full ophthalmic examination. The two brothers with ophthalmic disease were evaluated with color fundus photography, fluorescein angiography, optical coherence tomography (OCT), molecular genetic study (Group VI of Retinoschisis Consortium), pattern visual evoked potential (PVEP), and full field ERG.

RESULTS

Both patients presented funduscopic manifestations of vitre o retinal degeneration. They presented peripheral schisis and retinal detachment. However, foveal schisis had never been observed at funduscopy. A negative ERG was recorded in both. Six months after that, the younger brother showed a typical foveal schisis at fundus examination. A retinoschisis gene (XLRS1) mutation with transition of cytosine by thymine at position 608 (608C>T) had been identified in both.

CONCLUSIONS

Negative ERG is the most secure clinical marker to establish the diagnosis of juvenile retinoschisis. XLRS1 gene 608C>T mutation was described for the first time in a Portuguese family. (Eur J Ophthalmol 2005; 15: 638-40 ).

Phase I and Pharmacokinetic Study of Weekly Docetaxel, Cisplatin, and Daily Capecitabine in Patients with Advanced Solid Tumors

Purpose: Docetaxel, cisplatin, and capecitabine are three active chemotherapeutic agents with different mechanisms of action. This phase I study investigated the feasibility and pharmacokinetics of this combination given on a weekly schedule.

Experimental Design: Docetaxel and cisplatin were given i.v. over 30 minutes on days 1 and 8 and capecitabine was given orally bid on days 1 to 14 (every 21 days). Escalation occurred in cohorts of three patients until the maximum tolerated dose was defined. Pharmacokinetics studies of docetaxel and total and ultrafiltrate platinum after cisplatin administration were done on cycle 1 (with capecitabine) and cycle 2 (without capecitabine).

Results: Twenty-five patients were enrolled. Two of six patients at dose level 5 had a dose-limiting infection and diarrhea. One of six evaluable patients at dose level 4 (27 mg/m2 docetaxel, 27 mg/m2 cisplatin, 825 mg/m2 capecitabine) had a dose-limiting hypomagnesemia. Pharmacokinetics of docetaxel were similar on cycles 1 and 2. Area under the plasma concentrations versus time curves of total platinum was significantly greater in cycle 2 compared with cycle 1 (P = 0.001). There was no difference in the disposition of docetaxel on cycles 1 and 2.

Conclusions: The recommended docetaxel, cisplatin, and capecitabine dose for phase II studies is 27/27/825 mg/m2. The alteration in total and ultrafiltrate platinum disposition on cycle 2 compared with cycle 1 may be inherent to sequential cisplatin administration; however, prior treatment with capecitabine cannot be ruled out as a factor.

Learning and behavioural difficulties but not microcephaly in three brothers resulting from undiagnosed maternal phenylketonuria

Universal screening introduced in the 1960s has reduced the incidence of learning disability resulting from phenylketonuria (PKU), which is a treatable condition. Nonetheless, PKU may still be having an impact on the paediatric-age population. We report a woman with previously undiagnosed PKU who was born before the onset of universal screening. She is of normal intelligence, and so the diagnosis was not suspected until after the birth of her three children. Her serum phenylalanine concentration was found to be in excess of 1 mmol/L, well into the toxic range. She has had three sons, all of whom have a significant degree of learning disability resulting from intrauterine exposure to toxic levels of phenylalanine. None of the sons had microcephaly, a physical sign that, if present, might have helped to point towards the correct diagnosis. We suggest that maternal PKU should be suspected where there is sibling recurrence of cognitive impairment, particularly where the mother was born before the initiation of the neonatal screening programme for PKU.

Genotype-phenotype correlation in British families with X linked congenital stationary night blindness

AIM

To correlate the phenotype of X linked congenital stationary night blindness (CSNBX) with genotype.

METHODS

11 CSNB families were diagnosed with the X linked form of the disease by clinical evaluation and mutation detection in either the NYX or CACNA1F gene. Phenotype of the CSNBX patients was defined by clinical examination, psychophysical, and standardised electrophysiological testing.

RESULTS

Comprehensive mutation screening identified NYX gene mutations in eight families and CACNA1F gene mutations in three families. Electrophysiological and psychophysical evidence of a functioning but impaired rod system was present in subjects from each genotype group, although the responses tended to be more severely affected in subjects with NYX gene mutations. Scotopic oscillatory potentials were absent in all subjects with NYX gene mutations while subnormal OFF responses were specific to subjects with CACNA1F gene mutations.

CONCLUSIONS

NYX gene mutations were a more frequent cause of CSNBX than CACNA1F gene mutations in the 11 British families studied. As evidence of a functioning rod system was identified in the majority of subjects tested, the clinical phenotypes "complete" and "incomplete" do not correlate with genotype. Instead, electrophysiological indicators of inner retinal function, specifically the characteristics of scotopic oscillatory potentials, 30 Hz flicker and the OFF response, may prove more discriminatory.