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Annual Meeting Proceedings Part 1 - American Society of Clinical ...

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1547 General Poster Session (Board #2D), Sat, 1:15 PM-5:15 PM<br />

Features <strong>of</strong> familiality in a cohort <strong>of</strong> patients (pts) with sarcoma. Presenting<br />

Author: Georgios Lypas, Dana-Farber Cancer Institute, Boston, MA<br />

Background: Sarcomas occur in a number <strong>of</strong> cancer predisposition syndromes,<br />

yet genetic evaluation is rarely recommended for sarcoma pts. We<br />

broadly reviewed the family cancer histories <strong>of</strong> unselected pts in a tertiary<br />

center sarcoma clinic to explore the potential relevance <strong>of</strong> genetic assessment.<br />

Methods: Between 2005 and 2008, 397 pts (median age 52 years)<br />

with documented sarcoma who consented to research use <strong>of</strong> medical<br />

records and tissues also completed a family history questionnaire. Patient<br />

and family histories were reviewed for features suggesting hereditary risk<br />

(e.g. early age at diagnosis or familial clustering <strong>of</strong> certain associated<br />

diagnoses). Results: A family history <strong>of</strong> malignancy was noted in 301 <strong>of</strong> 397<br />

pts (76%). Seventy-six pts (19%) were diagnosed with 99 additional<br />

malignancies, most frequently breast cancer (n�23), prostate cancer (12),<br />

melanoma (12), thyroid cancer (6) or a second sarcoma (10). Sarcoma was<br />

diagnosed prior to or synchronously (within 6 months) with another<br />

malignancy in 20 pts and metachronously in 56 pts. In 18 pts, sarcoma<br />

arose within a prior radiation field. Thirty-seven pts (9%) had a sarcoma<br />

subtype associated with a recognized syndrome: desmoid fibromatosis<br />

(n�16), malignant peripheral nerve sheath tumor (11), PEComa/<br />

angiomyolipoma (6), retinoblastoma (3), and GIST with paraganglioma (1).<br />

Based on additional features, the associated syndromes were confirmed in<br />

6 <strong>of</strong> them (1.5% <strong>of</strong> the cohort): familial adenomatous polyposis (n�1),<br />

neur<strong>of</strong>ibromatosis type 1 (2), familial retinoblastoma (2), and Carney-<br />

Stratakis dyad (1). Thirty-three pts (8% <strong>of</strong> the cohort, or 16% <strong>of</strong> pts age<br />

�50) fulfilled TP53 testing criteria (Chompret, Birch or classical Li-<br />

Fraumeni Syndrome [LFS] criteria). Another 147 pts (37% <strong>of</strong> the entire<br />

cohort) did not fulfill LFS testing criteria, but were diagnosed with sarcoma<br />

before age 50 and had at least one first or second degree relative with a<br />

diagnosis <strong>of</strong> malignancy before age 50. Conclusions: Sarcomas are rare and<br />

diverse cancers. Given the potential association with cancer predisposition<br />

syndromes, genetic evaluation should be strongly considered in sarcoma<br />

pts based on age at diagnosis, histology, and family cancer history.<br />

1549 General Poster Session (Board #2F), Sat, 1:15 PM-5:15 PM<br />

Predictors <strong>of</strong> contralateral prophylactic mastectomy among patients with<br />

ductal carcinoma in situ (DCIS) who underwent evaluation for BRCA<br />

genetic testing. Presenting Author: Nisreen Elsayegh, University <strong>of</strong> Texas<br />

M. D. Anderson Cancer Center, Houston, TX<br />

Background: Patients with DCIS are at increased risk for developing<br />

contralateral breast cancer (CBC). Therefore, an increasing number <strong>of</strong><br />

women with DCIS are electing for contralateral prophylactic mastectomy<br />

(CPM). In a previous study involving 2072 women with DCIS, 13.5% chose<br />

CPM. In this study, we aimed to evaluate factors associated with CPM in<br />

patients with DCIS who underwent genetic counseling for BRCA. Methods:<br />

165 women with pure DCIS, who underwent genetic counseling, were<br />

included in the study. Patients’ characteristics were obtained from a<br />

prospectively maintained research database at UT M.D. Anderson Cancer<br />

Center. Univariate and multivaraite logistic regression analysis were used to<br />

determine predictive factors associated with CPM. Patients’ characteristics<br />

included age, marital and educational status, tumor markers, nuclear<br />

grade, family history with breast (BC) and ovarian cancer (OC), race,<br />

Ashkenazi Jewish ancestry, and BRCA genetic test results. Results: Out <strong>of</strong><br />

165 patients, 17(10.3%) were found to have a BRCA deleterious mutation.<br />

44(26.7%) underwent CPM. Younger patients (median � 45 yr) were more<br />

likely to elect for CPM than older patients (p� 0.0098). Patients who<br />

tested positive for a BRCA mutation were more likely to elect for CPM than<br />

those who tested negative or were not tested (p� 0.0001). Patients who<br />

had a family history <strong>of</strong> OC (15 (57.7%) were more likely to choose CPM<br />

than those who did not (p� 0.0004). These three factors remained<br />

significant in the multivariate model (p �0.008). Marital and educational<br />

status, tumor markers, nuclear grade, and family history <strong>of</strong> breast cancer<br />

were not significant predictors <strong>of</strong> CPM. Conclusions: The rate <strong>of</strong> CPM in<br />

patients with DCIS is high. Factors associated with increased likelihood <strong>of</strong><br />

undergoing CPM include family history <strong>of</strong> OC, age, and BRCA positivity.<br />

Further studies are needed to evaluate patients perception <strong>of</strong> CBC risk, and<br />

if this may play a role in the high number <strong>of</strong> CPM.<br />

Cancer Prevention/Epidemiology<br />

97s<br />

1548 General Poster Session (Board #2E), Sat, 1:15 PM-5:15 PM<br />

Analysis <strong>of</strong> mutations in formalin-fixed paraffin-embedded (FFPE) tumor<br />

samples from two phase II clinical trials using a Sequenom-based approach.<br />

Presenting Author: Maria Orr, AstraZeneca, Macclesfield, United<br />

Kingdom<br />

Background: Analysis <strong>of</strong> tumour samples for biomarker discovery, personalised<br />

health care and disease stratification is becoming increasingly<br />

important. Methods to detect somatic mutations are <strong>of</strong>ten limited by the<br />

requirement for a significant amount <strong>of</strong> input DNA, low sensitivity or low<br />

sample throughput. The aim <strong>of</strong> this work was to obtain a comprehensive<br />

mutation pr<strong>of</strong>ile <strong>of</strong> tumour samples taken from patients enrolled on two<br />

Phase II clinical trials. A Sequenom based approach was used to determine<br />

mutation pr<strong>of</strong>iles for the samples so that these could be correlated with<br />

response at some future date. Methods: After successfully piloting the<br />

Sequenom MassArray 4 platform on formalin fixed paraffin embedded<br />

(FFPE) tumour samples and tumour cell line admixes, we ran an exploratory<br />

analysis <strong>of</strong> 177 melanoma and 230 non small cell lung cancer (NSCLC)<br />

FFPE samples collected from two phase II clinical trials. DNA was extracted<br />

from the FFPE samples using the QIAmp DNA FFPE Tissue Kit (Qiagen).<br />

We designed a panel <strong>of</strong> 86 assays in 14 genes covering approximately<br />

160� mutations. Mutations were chosen based on mutation frequency and<br />

biological significance in these tumour types. Results: Using this approach<br />

we were able to detect concomitant mutation pr<strong>of</strong>iles in a significant<br />

percentage <strong>of</strong> samples using only approximately 20uL <strong>of</strong> FFPE DNA (500<br />

copies/�L average). Mutation status concordance was over 97% in BRAF<br />

and KRAS when compared to data generated via other approaches<br />

(sequencing, ARMS). Conclusions: Using Sequenom to screen tumour<br />

material, collected during clinical trials, is a feasible, rapid and comprehensive<br />

approach. Such an approach can be used to identify mutation pr<strong>of</strong>iles<br />

which correlate with patient response, potentially identify further patient<br />

stratification and help generate new hypotheses for further exploration.<br />

1550 General Poster Session (Board #2G), Sat, 1:15 PM-5:15 PM<br />

Pr<strong>of</strong>iling uptake <strong>of</strong> single site testing (SST) for familial cancer (CA) risk in an<br />

administrative genetic testing database. Presenting Author: Michael J. Hall, Fox<br />

Chase Cancer Center, Philadelphia, PA<br />

Background: Among the anticipated social and cost-saving benefits to identifying<br />

a mutation in a CA predisposition gene in an individual is the subsequent<br />

opportunity to perform SST in close relatives to confirm risk status and to guide<br />

risk-reducing interventions. Despite ample research into uptake <strong>of</strong> primary<br />

genetic testing for Lynch syndrome (LS) and hereditary breast ovarian syndrome<br />

(HBOS) among moderate- and high-risk individuals, few studies have focused on<br />

the resultant cascade <strong>of</strong> SST that is predicted to follow in families. Methods:<br />

Administrative data on 2,631 consecutive single-site mutation tests performed<br />

over a 3-month interval (12/1/10-2/28/11) were obtained from a commercial<br />

genetic testing database maintained by Myriad Genetic Laboratories. 14<br />

subjects (29 tests) were excluded due to multiple entries. Demographic,<br />

personal/family history (hx), and provider data are collected on a Test Requisition<br />

Form included in kits. All statistical tests are 2-sided (��0.05). Results: Women<br />

had SST more <strong>of</strong>ten than men (HBOS 82.8%; LS 65.5%). Mean age at time <strong>of</strong><br />

SST was 42.7 yrs, and was higher for HBOS than LS (p�0.01). Among subjects<br />

with hx <strong>of</strong> CA, mean age at CA diagnosis (dx) was similar (HBOS 48.6; LS 48.7<br />

yrs). Subjects reported CA in �1 relatives (range 1-16) with a mean age at dx<br />

40.1 yrs. Compared to HBOS, those tested for LS were more likely to report CA in<br />

a 1st degree relative (81.3 vs 74.4%, p�0.001) and a lower age <strong>of</strong> youngest CA<br />

dx in the family (p�0.001). Non-European ancestry was more common for<br />

HBOS SST than LS (30.0 vs 24.8%) (p�0.05). SST positive test rate was no<br />

different by syndrome or ancestry, but was higher for men (47.5 vs 42.0%,<br />

p�0.02). Conclusions: Uptake <strong>of</strong> commercial SST in high-risk families is uneven<br />

by age, sex, ancestry and CA syndrome. While between-syndrome variability in<br />

CA risks may explain some differences, more research is needed to understand<br />

barriers to uptake <strong>of</strong> SST among at-risk individuals if CA prevention goals are to<br />

be realized.<br />

Characteristics <strong>of</strong> 2,602 subjects undergoing SST for familial CA risk.<br />

%<br />

Sex F 79.5<br />

M 20.5<br />

Cancer Hx Y 19.9<br />

N 71.6<br />

Unreported 8.5<br />

Ancestry European 70.5<br />

Other 29.5<br />

Syndrome (genes) HBOS (BRCA1/2) 82.7<br />

LS (MLH1/MSH2/MSH6) 13.1<br />

Other 4.2<br />

Visit abstract.asco.org and search by abstract for the full list <strong>of</strong> abstract authors and their disclosure information.

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