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

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94s Cancer Prevention/Epidemiology<br />

1535 Poster Discussion Session (Board #24), Sun, 8:00 AM-12:00 PM and<br />

11:30 AM-12:30 PM<br />

Genetic sequence variant (GSV) in TERT-CLPTM1L (5p15.33 locus) and<br />

survival in platinum-treated stage-IV non-small cell lung cancer (NSCLC).<br />

Presenting Author: Abul Kalam Azad, Ontario Cancer Institute, Princess<br />

Margaret Hospital, Toronto, ON, Canada<br />

Background: Lung cancer is a leading cause <strong>of</strong> cancer-related mortality in<br />

North America. Besides tobacco smoking, inherited genetic factors can<br />

also influence the development <strong>of</strong> lung cancer. These genetic factors may<br />

lead to biologically distinct subsets <strong>of</strong> cancers that have different outcomes.<br />

We evaluated whether GSVs associated with lung cancer risk are<br />

also associated with overall survival (OS) and progress free survival (PFS) in<br />

platinum-treated stage-IV NSCLC patients. We chose this subset <strong>of</strong><br />

patients with lung cancer because they are uniformly treated and followed<br />

up at our institute (Princess Margaret Hospital). Methods: A total <strong>of</strong> 32<br />

candidate GSVs in 21 genes previously reported to be associated with lung<br />

cancer risk were genotyped in 188 platinum-treated NSCLC stage-IV<br />

patients. Illumina Custom GoldenGate Genotyping Panel was used for the<br />

genotyping assay platform. Multivariate Cox proportional hazard models<br />

adjusted for the potential clinical prognostic factors were generated for OS<br />

and PFS. Results: Median age is 60 yr (range: 31-81); 73% with<br />

adenocarcinoma. Median follow-up time is 27 mo; median OS is 16 mo and<br />

PFS is 8 mo. The top significant GSV was rs4975616 (g.1315660G�A) in<br />

telomerase reverse transcriptase (TERT) and cleft lip and palate transmembrane<br />

1-like (CLPTM1L) gene on chromosome 5p15.33. The adjusted<br />

hazard ratio (aHR) for OS was 0.76 (95% CI: 0.58-0.99; p�0.04) and for<br />

PFS aHR was 0.70 (95% CI: 0.55-0.90; p�0.005) for each protective<br />

allele, respectively. This GSV has previously been associated with lung<br />

cancer risk in genome-wide association study (PMID: 19654303).<br />

Conclusions: The TERT-CLPTM1L:rs4975616 GSV is not only a risk factor<br />

for lung cancer but also is associated with survival in patients with stage-IV<br />

NSCLC treated with platinum based chemotherapy. GSVs may be able to<br />

define subsets <strong>of</strong> patients with different risk and prognosis <strong>of</strong> NSCLC.<br />

Future studies should evaluate whether this GSV is predictive or prognostic.<br />

1537 General Poster Session (Board #1A), Sat, 1:15 PM-5:15 PM<br />

Correlation <strong>of</strong> breast cancer risk in European BRCA2 mutation carriers with<br />

birth cohort. Presenting Author: Muy-Kheng Maria Tea, Medical University<br />

<strong>of</strong> Vienna, Department <strong>of</strong> OB/GYN, Division <strong>of</strong> Senology, Vienna, Austria<br />

Background: Mutations in the Breast Cancer Gene 1 (BRCA1) and Breast<br />

Cancer Gene 2 (BRCA2) lead to an elevated risk <strong>of</strong> developing breast (BC)<br />

and ovarian cancer (OC). However, risk estimates vary, depending on the<br />

study population. Furthermore, there are indications that birth cohort can<br />

influence the cancer risk. We investigated the risks for BC and OC<br />

associated with BRCA2 mutations in a cohort <strong>of</strong> female mutation carriers <strong>of</strong><br />

a genetically heterogeneous central European population who were identified<br />

by molecular genetic testing in our institute. Methods: This study<br />

included 171 Caucasian women from Austria who underwent genetic<br />

counseling and where molecular genetic analysis identified a mutation in<br />

the BRCA2 gene at the Medical University <strong>of</strong> Vienna, Division <strong>of</strong> Senology,<br />

in Austria. A total <strong>of</strong> 57 healthy and 114 affected BRCA2-carriers were<br />

detected. The risk was estimated using the product limit method. The log<br />

rank test was used to compare different strata. Results: The risk <strong>of</strong><br />

developing cancer to age 70 was found to be 85% for BC (95% CI<br />

77–93%) and 31% for OC (95% CI 16–46%) in our BRCA2 study<br />

population. Female BRCA2-carriers born in 1958 or later were at a<br />

significantly higher risk <strong>of</strong> developing BC (p�0.001; 88% vs. 46% to age<br />

40) but not <strong>of</strong> OC (p is not significant; 0% vs. 2% to age 40) compared to<br />

mutation carriers born earlier. Conclusions: We conclude that female<br />

BRCA2 mutation carriers should also be counseled about their cohortdependent<br />

cancer risk, especially for breast cancer. Further research about<br />

variables that may affect cancer risk like lifestyle-related factors should be<br />

considered.<br />

1536 Poster Discussion Session (Board #25), Sun, 8:00 AM-12:00 PM and<br />

11:30 AM-12:30 PM<br />

Second malignant neoplasms (SMN) among 18,627 testicular cancer<br />

survivors (TCS) after chemotherapy (CHEM) or surgery (SURG). Presenting<br />

Author: Chunkit Fung, James P. Wilmot Cancer Center, University <strong>of</strong><br />

Rochester School <strong>of</strong> Medicine and Dentistry, Rochester, NY<br />

Background: Increased risks <strong>of</strong> SMN after radiotherapy (RT) for testicular<br />

cancer (TC) are well established. Few population-based studies, however,<br />

have focused on SMN risk among a contemporary group <strong>of</strong> TCS managed<br />

initially with non-RT approaches, including CHEM. Methods: Standardized<br />

incidence ratios (SIR) <strong>of</strong> SMN stratified by site and time since TC diagnosis<br />

were calculated for 18,627 TCS reported to the SEER program (1980-<br />

2008) who initially had CHEM (n�8,058) or SURG (n�10,569) alone<br />

without RT, with each cohort accruing 65,398 and 92,681 person-years<br />

(PY) <strong>of</strong> follow-up respectively. Results: After CHEM, significantly increased<br />

risks <strong>of</strong> solid cancers (n�154; SIR 1.3; 95% CI 1.1-1.5; absolute excess<br />

risk (AER) 5.4 per 10,000 PY) and leukemias (n�18, SIR 3.9; 95% CI<br />

2.3-6.1; AER 2.0) were observed. Solid cancer risk remained elevated for<br />

� 20 yrs, whereas excess leukemias were concentrated within 10 years<br />

after diagnosis. SIRs for solid cancers during the �1, 1-4, 5-9, 10-14,<br />

15-19, and 20� yr periods were 2.0 (95% CI 1.03-3.5), 1.4 (95% CI<br />

0.97-2.0), 0.8 (95% CI 0.5-1.2), 1.3 (95% CI 0.9-1.8), 1.6 (95% CI<br />

1.05-2.2), and 1.5 (95% CI 0.95-2.2) respectively (P-trend 0.5) whereas<br />

SIRs for leukemia were 3.2, 9.9 (P�0.05), 2.6, and 2.3 respectively, with<br />

no cases reported in the latter 2 intervals. Median latencies to the<br />

development <strong>of</strong> solid cancers and leukemia were 12.5 yr (0.1-28) and 2.5<br />

yr (0.1-14) respectively. Increased site-specific risks were apparent for<br />

cancers <strong>of</strong> liver (SIR 1.9; 95% CI 0.6-4.4); pancreas (SIR 2.1; 95% CI<br />

0.8-4.6); s<strong>of</strong>t tissue (SIR 4.9; 95% CI 2.1-9.7); bladder (SIR 1.9; 95% CI<br />

1.02-3.3); kidney (SIR 2.6; 95% CI 1.4-4.3); brain/CNS (SIR 1.8; 95% CI<br />

0.7-3.7), and thyroid (SIR 3.9; 95% CI 2.1-6.6). Secondary leukemias<br />

included 16 non-lymphocytic and 2 lymphocytic leukemias. In contrast,<br />

among TCS managed initially with SURG alone, no excess solid cancers<br />

were observed (n�198; SIR 1.0; 95% CI 0.8-1.1), albeit an increased risk<br />

<strong>of</strong> leukemia (n�15; SIR 1.9; 95% CI 1.1-3.2, AER 0.8) was seen.<br />

Conclusions: Future analytic studies should further evaluate the sitespecific<br />

risks <strong>of</strong> SMN after modern CHEM for TC and the baseline risk<br />

among patients managed with non-cytotoxic approaches.<br />

1538 General Poster Session (Board #1B), Sat, 1:15 PM-5:15 PM<br />

Identification <strong>of</strong> new susceptibility genes in familial breast cancer by<br />

exome sequencing. Presenting Author: Henry T. Lynch, Creighton University,<br />

Omaha, NE<br />

Background: Familial breast cancer was described in the early 1970s with<br />

its syndromy confirmed by the discovery <strong>of</strong> BRCA germline mutations in the<br />

1990s. BRCA mutations account for less than 10% <strong>of</strong> affected families.<br />

Efforts made in the past two decades have resulted in limited results in<br />

identifying additional susceptibility genes for familial breast cancer.<br />

Methods: Using exome sequencing, we analyzed eight members in a<br />

BRCA1-, BRCA2-, p53- and PTEN-negative breast cancer family; five with<br />

breast cancer and three unaffected. Mutation candidates were idenified by<br />

bioinformatics analysis, experimentally validated by Sanger sequencing<br />

and their damaging effect was predicted by the SIFT program. Validated<br />

mutations were also tested in 42 additional breast cancer samples from<br />

BRCA-negative breast cancer families. Results: We identified 55 nonsynonymous<br />

germline mutations affecting 49 genes in multiple members<br />

<strong>of</strong> this family, 20 <strong>of</strong> 22 selected mutations predicted to cause damaging<br />

effects were validated. As an exemplar, two mutations in the MYST4 gene<br />

were detected at the C terminal (p.D1516Y and p.R1577C), validated, and<br />

predicted to cause damaging consequences. MYST4 is a histone acetyltransferase<br />

(Champagne, N. et al. JBC. 274, 28528-28536,1999). It contains<br />

a C2HC-type finger and a PHD-type zinc finger. Its N-terminal is involved in<br />

transcriptional repression while its C-terminal is involved in transcriptional<br />

activation and interacts with important transcriptional regulators RUNX1<br />

and RUNX2. MYST4 is involved in DNA replication, transcriptional regulation,<br />

and epigenetic modification <strong>of</strong> chromatin structure. A translocation<br />

t(10;16)(q22;p13) between CREBBP and MYST4 was identified in acute<br />

myeloid leukemia. The 20 validated germline mutations were tested by<br />

Sanger sequencing in 42 additional breast cancer cases from 26 BRCAnegative<br />

families. None <strong>of</strong> the 20 mutations were detected. Conclusions:<br />

Results show that remaining unknown susceptibility genes are likely<br />

family-specific and can be detected in each affected family using genome<br />

sequencing approaches. These results may be the first reported in an exome<br />

sequencing study <strong>of</strong> BRCA-negative breast cancer families.<br />

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