Abstract S4-01: Identification of early versus late drivers of breast tumors and metastasis

Background: The molecular characterization of primary breast cancers has led to signatures identifying risk of future metastasis and survival; however the underlying biology driving metastasis development is largely unknown.

Methods: Utilizing a Rapid Autopsy Program, we have collected 61 metastatic breast cancer tumors from 7 individuals (4 triple negative, 2 HER2+, 1 ER+/HER2-) including primary tumors and 3-6 metastases/patient. We performed mRNA and DNA exome sequencing. We next used DawnRank, a novel network-based method that integrates DNA and RNA data to identify computationally determined "driver" genes (i.e. a DNA variant that significantly alters its gene expression-network) in each individual sample. Phylogenetic tree and clonal analysis were also performed, with the computationally determined drivers mapped onto these trees.

Results: The breast cancer primaries were molecularly subtyped as 5 Basal-like, 1 HER2-Enriched, and 1 Luminal A; in all cases, the metastases clustered immediately adjacent to their primary tumor by hierarchical clustering analysis. Widespread DNA copy number alterations identified in the primary tumors were typically maintained throughout metastasis. On average, 1.9 ± 1.3% of DNA copy number altered genes, and 2.4 ± 0.95% of the somatic mutations per tumor were identified as "drivers" by DawnRank. There were an average of 199 ± 72 total drivers per tumor due to copy number alterations (amplifications or deletions) and 12 ± 23 drivers per tumor from somatic mutations.

Phylogenetic tree analysis demonstrated that the majority of DNA copy number events occurred early in tumor development. Founding clones were defined as genetic events present in the primary and all matched metastases. Chr5q13 loss and TP53 mutation were the only consistent alterations in the founding clones of all 7 patients. Drivers on chr5q13 identified in this cohort include CCNB1, CDK7, and TAF9. Among the basal-like patients, all 5 patients' TP53 mutations were identified as a driver by DawnRank.

39% and 20% of drivers from copy number gains and losses, respectively, were identified in the primary tumor, while another 34% and 30% were not seen in the primary but were present in more than 1 metastasis within each patient. Metastasis-enriched copy number drivers not seen in any primary included FLT1, MAP2KR, and ARNT.

38% of the drivers resulting from somatic mutations were established in the primary and maintained in metastases. Of the remaining drivers from somatic mutation, only 18% were shared among metastases but not seen in the primary while 47% were not seen in any other tumor within a given patient (i.e. private to a single sample). TP53, PSEN1, CDC27, HDAC1, and BRCA1 were somatic mutation drivers established early in metastatic development, while CCNH was a consistent late driver.

Conclusions: We present a novel computationally determined genetic "driver" analysis of matched breast cancer primaries and multi-organ metastases. In this cohort, our results suggest that most genetic drivers in a single tumor are based on copy number aberrations, are established early, and are maintained in metastases. In contrast to copy number, drivers from somatic mutations are acquired later, and most of the metastases continued to acquire new genetic driving features.

Citation Format: Siegel MB, He X, Chen M, Hou JP, Garrett AL, Dye JB, Silva GO, Usary JE, Moylan VJ, Brady CM, Ma J, Thorne LB, Hoadley KA, Parker JS, Anders CK, Carey LA, Perou CM. Identification of early versus late drivers of breast tumors and metastasis. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr S4-01.

Methylphenidate-induced erections in a prepubertal child

Methylphenidate is a medication used routinely in the management of attention deficit hyperactivity disorder. We report a case of a prepubertal child who developed unwanted erections after commencing a response-adjusted dosing regimen of sustained release methylphenidate. Despite priapism being a rare adverse reaction associated with methylphenidate, physicians and parents need to be aware as it can have significant long-term complications.

The impact of the National Treatment Purchase Fund on numbers of core urology training cases at University Hospital Galway

Since the National Treatment Purchase Fund (NTPF) scheme was introduced in 2002, public patients waiting longer than three months for investigations and treatment are offered care in the private medical sector. Our aim was to assess the impact of the NTPF scheme on the number of training cases performed at University Hospital Galway (UHG). The number and type of urological procedures performed in the private medical sector under the NTFP scheme in 2008 were obtained from the UHG waiting list office. The number of these procedures performed on public patients by trainees at UHG in 2008 was determined retrospectively by reviewing theatre records. A significant number of core urology procedures were performed in the private sector via the NTPF scheme. Cancer centre designation and implementation of the EWTD will also place further pressures on urological training opportunities in Ireland.

An open-label pilot study of cannabis-based extracts for bladder dysfunction in advanced multiple sclerosis

The majority of patients with multiple sclerosis (MS) develop troublesome lower urinary tract symptoms (LUTS). Anecdotal reports suggest that cannabis may alleviate LUTS, and cannabinoid receptors in the bladder and nervous system are potential pharmacological targets. In an open trial we evaluated the safety, tolerability, dose range, and efficacy of two whole-plant extracts of Cannabis sativa in patients with advanced MS and refractory LUTS. Patients took extracts containing delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD; 2.5 mg of each per spray) for eight weeks followed by THC-only (2.5 mg THC per spray) for a further eight weeks, and then into a long-term extension. Assessments included urinary frequency and volume charts, incontinence pad weights, cystometry and visual analogue scales for secondary troublesome symptoms. Twenty-one patients were recruited and data from 15 were evaluated. Urinary urgency, the number and volume of incontinence episodes, frequency and nocturia all decreased significantly following treatment (P <0.05, Wilcoxon's signed rank test). However, daily total voided, catheterized and urinary incontinence pad weights also decreased significantly on both extracts. Patient self-assessment of pain, spasticity and quality of sleep improved significantly (P <0.05, Wilcoxon's signed rank test) with pain improvement continuing up to median of 35 weeks. There were few troublesome side effects, suggesting that cannabis-based medicinal extracts are a safe and effective treatment for urinary and other problems in patients with advanced MS.

Parallel changes in bladder suburothelial vanilloid receptor TRPV1 and pan-neuronal marker PGP9.5 immunoreactivity in patients with neurogenic detrusor overactivity after intravesical resiniferatoxin treatment

OBJECTIVE

To compare PGP9.5 and transient receptor potential vanilloid receptor (TRPV1) suburothelial immunoreactivity between controls and patients with spinal neurogenic detrusor overactivity (NDO) before and after treatment with intravesical resiniferatoxin, as suburothelial PGP9.5-staining nerve fibres decrease in patients with spinal NDO who respond to intravesical capsaicin, and TRPV1 is present on these suburothelial nerve fibres in normal and overactive human urinary bladder.

PATIENTS AND METHODS

Patients with refractory NDO were enrolled in a prospective, randomized, parallel-group, double-blind, placebo-controlled trial using escalating doses of resiniferatoxin to a maximum of 1 micro mol/L. Flexible cystoscopic bladder biopsies obtained at baseline, 4 weeks after each instillation and at the time of maximum clinical response were compared with biopsies taken from control subjects. Frozen sections were incubated with rabbit antibodies to TRPV1 and PGP9.5, and assessed using standard immunohistochemical methods. PGP9.5 nerve density was analysed using a nerve-counting graticule by an observer unaware of sample origin. Another two independent observers unaware of each other's results used a random grading scale to evaluate TRPV1 nerve fibre density and intensity. The immunohistochemistry results were compared with histology findings (haematoxylin-eosin), and the Mann-Whitney test used to assess any differences (P < 0.05 significant) and the Pearson test for correlation.

RESULTS

There were eight controls and 20 patients with spinal NDO, 14 (five clinical responders and nine not) who received the maximum dose of resiniferatoxin. There were more PGP9.5 and TRPV1 nerve fibres in patients with NDO than in controls (P = 0.007 and 0.002, respectively). Immunoreactivity before resiniferatoxin was similar in both groups for both PGP9.5 and TRPV1. In responders there were fewer PGP9.5 and TRPV1-positive fibres after treatment (P = 0.008 for each) but no change in those not responding. Changes after treatment for TRPV1 correlated well with those for PGP9.5 (r = 0.88, P < 0.001).

CONCLUSIONS

The decrease of PGP9.5 and TRPV1 immunoreactive nerve fibres in responders to resiniferatoxin (to levels in control tissues) suggests that the increased numbers of nerve fibres in patients with NDO are mainly of sensory origin and express TRPV1. As baseline nerve fibre values were similar in responders and nonresponders, an additional factor may account for the difference in treatment outcome.

Endothelial nitric oxide synthase expression in neurogenic urinary bladders treated with intravesical resiniferatoxin

OBJECTIVE

To investigate endothelial nitric oxide synthase (eNOS) immunoreactivity in bladder biopsies from patients with neurogenic detrusor overactivity (NDO) before and after treatment with intravesical resiniferatoxin, and compare this with control material; the distribution of two other vascular markers, von Willebrand Factor (vWF) and the vascular endothelial growth factor (VEGF), was also studied.

PATIENTS AND METHODS

Flexible cystoscopic bladder biopsies from eight controls investigated for asymptomatic microhaematuria and 19 patients with refractory spinal NDO enrolled in a clinical trial of intravesical treatment with escalating doses of resiniferatoxin were immunostained with polyclonal rabbit antibodies for eNOS, vWF and VEGF. Fewer baseline NDO specimens (eight) were available for vWF and VEGF staining. Computerized image analysis was used to quantify immunoreactivity, and the Mann-Whitney test for statistical analysis.

RESULTS

eNOS immunoreactivity was found in the suburothelium and less often in the urothelium, with a distribution indicating a location in small blood vessels at the urothelium-suburothelium junction. Immunostaining for vWF showed a similar location. There was a trend to higher eNOS values before treatment in those responding than in those not responding to resiniferatoxin (P = 0.059), and a significant reduction in eNOS immunoreactivity after successful treatment (P = 0.016). VEGF staining was weaker but there was a significant increase in pretreatment biopsies of responders to resiniferatoxin (P = 0.048). Clinical and histopathology features were similar in both groups.

CONCLUSIONS

The trend for higher eNOS expression in patients with NDO who responded to resiniferatoxin suggests that increased vasculature or vasodilatation in the suburothelium may be necessary for successful intravesical treatment. Further studies with more patients are required to confirm this relationship and to examine the mechanisms underlying changes in vasculature with levels of bladder overactivity.

Treatment of erectile dysfunction with sildenafil citrate (Viagra) in parkinsonism due to Parkinson's disease or multiple system atrophy with observations on orthostatic hypotension

OBJECTIVES

To assess the efficacy and safety of sildenafil citrate (Viagra) in men with erectile dysfunction and parkinsonism due either to Parkinson's disease or multiple system atrophy.

METHODS

Twenty four patients with erectile disease were recruited, 12 with Parkinson's disease and 12 with multiple system atrophy, into a randomised, double blind, placebo controlled, crossover study of sildenafil citrate. The starting dose was 50 mg active or placebo medication with the opportunity for dose adjustment depending on efficacy and tolerability. The international index of erectile function questionnaire (IIEF) was used to assess treatment efficacy and a quality of life questionnaire to assess the effect of treatment on sex life and whole life. Criteria for entry included a definite neurological diagnosis and a standing systolic blood pressure of 90-180 mm Hg and diastolic blood pressure of 50-110 mm Hg, on treatment if necessary. Blood pressure was taken at randomisation (visit 2) and crossover (visit 5) lying, sitting, and standing, before and 1 hour after taking the study medication in hospital.

RESULTS

Sidenafil citrate was efficacious in men with parkinsonism with a significant improvement, as demonstrated in questionnaire responses, in ability to achieve and maintain an erection and improvement in quality of sex life. In Parkinson's disease there was minimal change in blood pressure between active and placebo medication. In multiple system atrophy, six patients were studied before recruitment was stopped because three men showed a severe drop in blood pressure 1 hour after taking the active medication. Two were already known to have orthostatic hypotension and were receiving treatment with ephedrine and midodrine but the third had asymptomatic hypotension. However, the blood pressures in all three had been within the inclusion criterion for the study protocol. Despite a significant postural fall in blood pressure after sildenafil, all patients with multiple system atrophy reported a good erectile response and were reluctant to discontinue the medication.

CONCLUSIONS

Sidenafil citrate (50 mg) is efficacious in the treatment of erectile dysfunction in parkinsonism due to Parkinson's disease or multiple system atrophy; however, it may unmask or exacerbate hypotension in multiple system atrophy. As Parkinson's disease may be diagnostically difficult to distinguish from multiple system atrophy, especially in the early stages, we recommend measurement of lying and standing blood pressure before prescribing sildenafil to men with parkinsonism. Furthermore, such patients should be made aware of seeking medical advice if they develop symptoms on treatment suggestive of orthostatic hypotension.

A prospective evaluation of the efficiency of early postoperative bladder emptying after the Stamey procedure or pubovaginal sling for stress urinary incontinence

PURPOSE

The pubovaginal sling has been criticized as having a higher incidence of postoperative voiding dysfunction than other surgical approaches for the management of stress urinary incontinence. In 2 similar patient groups we prospectively compared the rates of early postoperative voiding dysfunction after the pubovaginal sling or Stamey procedure.

MATERIALS AND METHODS

Between June 1995 and January 1997, 50 consecutive patients underwent the pubovaginal sling or Stamey procedure. Emptying efficiency was measured 48 hours postoperatively by suprapubic catheter in the Stamey group and intermittent catheterization in the pubovaginal sling group. When emptying efficiency was greater than 75%, intermittent catheterization was stopped or the suprapubic catheter was removed.

RESULTS

There was no statistically significant difference in emptying efficiency for the first 3 voids using the Dunn multiple comparison method. Median voiding efficiencies were 37%, 43% and 61% with the Stamey procedure in group 1 (mean 43%, 45% and 54%), and 60%, 75% and 75% with the pubovaginal sling in group 2 (mean 49%, 68% and 69%), respectively. The mean number of intermittent catheterizations performed in patients with the pubovaginal sling was 5.7 in less than 1 day. In the Stamey group the suprapubic catheter was removed an average of 6 days postoperatively. The mean duration of hospital stay was similar for the sling and Stamey groups (5.4 versus 6 days, respectively). There were 2 patients in each group who were voiding inefficiently after day 7. Voiding efficiency was restored at 53 and 86 days in the 2 patients with slings and at 18 days in 1 of the 2 who underwent the Stamey procedure, respectively. The second patient who underwent the Stamey procedure was able to void without using the catheter at all, and it was removed 30 days postoperatively when emptying efficiency was confirmed greater than 75%.

CONCLUSIONS

These data show that early postoperative voiding dysfunction, measured using bladder emptying efficiency, after the pubovaginal sling is no more common than after the Stamey procedure and help justify the broadened indications for pubovaginal sling for treatment of stress urinary incontinence.