P-279 Lung cancer-specific biomarkers of tumor suppressor gene silencing

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Posters/Early detection~Prevention

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RASSFIA methylatlon and k-ras In eputum of paUente with lung carcinoma F Thunnissen A Bolijn. B Hol. C Pnnsen Canisius-V~lhe/rnina Hospital, Ntjme#en, The Netherlands Background: K-ras mutations are present in about 30% of the patients with

adenocarcinoma RASSF1A expression is frequently altered in lung carcinoma RASSF1A protein contains a Ras association domain like that of Ras effectors and is predicted to exert its functJen through a Ras signal transduction pathway The aim of this study was to determine the percentage of sputum specimens from patients with lung cancer with K-ras mutations and RASSF1A hypermethylafion Method=i: We collected 3 day pooled sputum from 27 patients with lung cancer (15 squamous (:ell carcinomas. 5 small cell carcinomas. 4 adenocarcinomas. 3 large coil caranomas. 1 sample with tumour necrosis (cytology: non small cell carcinoma). One patient had a double turnour: squamous (:ell as well as adenocarcinoma. Sputum specimens were examined for K ras mutations vath the Po~nt4_XACCT method and RASSF1A promoter hypermethylation by MSR Results: K ras mutation was detected in 2 of the 27 sputum samples (8%). K-ras mutatJens in biopsy or resection specimens were detected in 2 of the 4 adenocarcinomas (50%). but not in the other carcinomas From one sputum specimen of one palJent with adenocarcinoma there was insufficient DNA material left. after K-r'as analysis, for further analysis of RASSF1A methylatJon RASSF 1A methylation was detected in 16 out of 26 sputum specimens (62%) RASSF1A methylation in sputum samples was detected in all 5 cases with small cell lung cancer, g out of 1,5 sduamous cell carcinomas. 1 out of 3 adenocarcinornas, and 1 out of 3 large cell carcinomas. With respect to the two sputum specimens with K4-as mutation, in one case the same TGT mutation for K ras was found in tumour and sputum as well as RASSF1A methylation in sputum. In the second case with K4-as mutation in the sputum (TGT) only a small biopsy of a large cell carcinoma was available. but negative for K4"as mutation in the tumour, while the sputum sample was unmethylated. Conclusion: K-ras mutation is infrequently detected in sputum of patients with lung cancer In contrast. RASSF1A hypermethylatJon is frequently present in sputum of patients with lung cancer and is a premising marker for detection of lung cancer in sputum

~Lung

cancer-specific blomarkers of tumor suppressor gene silencing

M Teekman I J Park~.L Chen ~.J Zhou ~.R Brena 2.M Chan 2 . T H u a n g 2. C. Plass 2. ~H. Lee Motttt Caner Center & Research lnstrtute, Tampa,

Flonda, USA: 20h/o State Un/verslty, Columl~us, OH, USA Background: We hypothesize that gene loci silenced by methylalJon in tumor bet not in adjacent uninvolved tissues correspond to specific pathways important for the induction/maintenance of olenal (neoplastic) expansion. Applying the technique of Restriction Landmark Genome Scanning (RLGS). we have conducted a genomewlde scan of leel that are hypermethylated in lung tumor compared to the adjacent, nor. involved lung tissue reseoted from the same incivldual (same genetic background, same exposure). The corollary is that by controlling for exposure and genetic venation, any differentially methylated loci discovered would be cancer specific. The robustness of this discovery approach is apparent from our data that descdbe 21 loci net previously associated with lung cancer inducing three recently reported to be silenced by methylalJon in cancers of other organs Our strategy develops a panel of hypermethylated loci by supplementing RLGS-detected genes with the methylated sequences detected by expression arrays The contribution of histone modifieatJon to silencing of these loci is determined by chromosome immunoprecipitatJon to fully charaetenze epigenetJc silencing Methods & Results: We present data that show (1) the association between hypermethylat]on and histone modification in the promoter raglan with gene silencing, and (2) the reversible epigenet]c control of ALEX5 expression. a differentially methylated key component of the lipoxygenase pathway not previously known to be epigenetically silenced in lung cancer, but recently implicated in colon cancer. We also examine expression of the genes in the Transforming Growth Factor ? type II receptor (T?R II) pathway. Conduslone: We believe this approach for select3on of epigenetJcally silenced loci in pathways critical to carcinogenesis is most likely to lead to a valid panel of sputum biomarkers of lung cancer

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Recruitment and firet ecreenlng reeulte of the Dutch-Belgian lung cancer ecreenlng trial (NELSON)

C van lersel %2 H de Koning I . R Vliegenthart ~. H Gietema 4. W Mall 4. E. Th Scholten ~. K. Nackaerts e. M. Oudkerk 3. R. van Klaverer~. 1Department

Public Health, Erasmus MC, Rotterdam, The Nether~ands, 2Department Pulmonology, Erasmus MC, Rotterdam, The Netherlands, 3Department Radology, University Medical Canter Groningen, Groningen, The Nether~ands, 4Department of Radtolngy, Umverslty MeScal Center Utrecht, Utrecht, The Nether~ands, ~Department of Radiology, Kennemer Gasthu~s, Haarlem, The Ne~erlands, ~Department ct Pulmonology, Untversrty Hospital Gasthulst~erg, Leuven, Balgmm Background: Eady lung cancer detection with X4-ay was unable to reduce lung cancer mortality. Results of several completed cohort studies with low dose spiral CT screening have demonstrated that lung eancer ean be detected at an early stage To determine whether spiral CT screening leads to a lung cancer mortality benefit, and whether lung cancer screening is cost-effecOve the largescale randomised Dutch43elgian lung cancer screening tdal (NELSON) has been initiated Approximately 20.000 subjects will be randomized (1:1) to spiral CT screening and usual care Lung cancer mortality in both study arms will he traced by linldng our database to Statistics Netherlands and the NalJonal Cancer Registry. Methods: To identify subjects with a high rlsk for lung cancer, a health questionnaire was sent to 362.644 men aged 50-74 in seven Dutch public health disthcts and 14 municipalities in Belgium. Responders on the first mailing who smoked at least 16 cigarettes a day for at least 26 years or at least 11 cigarettes a day for at least 31 years were invited for participation. After giving informed consent, participants were randomized to screening or usual care CT screenings started in Apdl 2004 CT scans are performed with 16 detector multi slice Spiral CT scanners and Siemens Lungcare ® workstations and software for volumethc analyses. The Lungcare radiological data are automatically uploaded in the NELSON Management System (NMS). At baseline screening, the nodules are categorized into six groubs; Category 0 (no nodules or nodules < 15 mm3): Category I and II (non-significant nodules: annual repeat screening); Category III (Indeterminate: repeat screening after 3 months); Category IV (susp4aous for lung cancan work4Jp by pulmonologlst) and Category V (growing lesion on 3 months repeat screening: work up by pulmenologist). Results: 106.8,50 (29.5%) subjects responded on the first health questionnaire. At least 19.776 (18.5%) met the selection orlterla and were invited for participation. After sending a reminder. 11.000 people (55.6%) signed the informed consent form and were randomized (1:1) Of the first 2133 baseline screenings. 844 pa~cipants had Cat 0 nodules. ,506 Cat I nodules. 1802 Cat II nodules. 667 Cat III nodules, and 28 Cat IV nodules (in 27 participants) Our preliminary data show that at least ten of 28 Cat IV nodules were malignant Of the 213 participants who underwent a 3-month repeat scan. in at least 11 participants a growing nodule was found So far. in one participant the nodule was found to be malignant Evaluations of the other nodules are not completed yet. Conclusion: The response rate on the general health questionnaire (30%) and the number of eligible persons among them (19%) was lower than expected The high participation rate (56%) among the eligible persons was not sufficient to roach the set study am of appro~mately 29.000 participants. Therefore. a second recruitment round wlll start soon to recruit 3000-4000 adcit]onal participants. At the WCLC meeting data on lung cancer detection rates, disease stage and pathological diagnosis of the first 2900 screenees will be presented ~-~

Tberapeutlc choice of physicians on the aesumpUon that they

suffer from lung carolnoma: Survey D. Zlvkovlc~. A. Radosavijevic z, Z. Celeblc ~ . O. BoJovic~. 1Institute for Lung D~seases Montenegro, NlkSlC, Yu#oslawa; 2Institute for Lung Dtseases,

Baograd, Ser~a InlTodu¢tlon: Att~de of physicians towards current options of lung cancer (LC) Izeatmens vanes and depends on numerous factors. A survey of physicians was made in order to reveal thedr therapeutic options in a hypothebcal case that they were personally affected by LC. Methods: The questionnaire was filled in by 46 phys~aans pulmonologists. where the3, selected therapeutic regimes in different stages of SCLC and NSCLC 36 physicians worked in hospitals and 10 in out-patient clinics treating montNy 2 ,50 pts (meclan 1(3) with LC The average age of the physicians was 38 yrs (range 2?" ,56) and two thirds were women Results: In eases of NSCLC. stages I. I1. Ilia. IIIb and IV 41 (89%). 40 (87%). 29 (63%). 27 (,59%) and 2 (4%) physicians decided on surgery, in combinalJen with postoperative CT and/or RT in cases of squamous-cs and CT in eases of adene-ea. Nonsurglcal methods. CT and/or RT in the same stages of NSCLC wore selected by 1 (2%). 1 (2%). 10 (22%). 11 (24%) and 10 (22%) physicians. They preferred cisplat]ne, etoposide, mitornycin and vinctPalcaloids. Only symptomatic therapy was selected by 4 (9%). 5 (11%). 5 (11%). 7 (15%) and 29 (63%) physicians while 0.0. 2. 1 and 4 physicians decided on altematrve