Materials and method s: T1–2N0 OSCC patients who have to wait surgery more than 2 weeks from histologi cal diagnosis were admin- istered S-1 (80 mg/m 2/day) until surgery. We analyzed 48 patients who took S-1 orally more than 7 days about anti-tumor effect and prognosis .

Results: Mean administrati on period was 15.9 days (7–42 days),and mean total dosage was 1705.4 mg. Clinical anti-tu mor effect was CR:7, PR:7 and NC:34 patients. The clinical response rate was 29.2%. Histolo gical anti-tumor effect was CR:6, PR:11 and NC:31 patients and histological response rate was 35.4%. Local recurren ces and late metastases were seen in three patients (6.3%) and 9 patients (18.8%), respectivel y. Histolo gical NC cases developed local recurren ce (9.7%) and late metastasis (25.8%)whereas almost patients who revealed CR or PR did not. Three- year survival rate was 100% in CR and PR cases, and 87.8% in NCcases. Adverse effects more than grade 2 were not appeared. Atleast 2-weeks administrati on is necessary to obtain anti-tumor effect.

Conclusions: In histological ly effective cases, develop ment of local recurren ce and late metastasis was very low and prognosi s is excel- lent. The short term administrat ion of S-1 during waiting surgery issafe and useful for early stage OSCC patients.

doi:10.1016/j.oraloncolo gy.2013.03.427

PP185

Dental rehabili tation with distracti on osteogene sis and dental implant in patient s of oral cancer involved mandible Kil-Hwa Yoo, Seung-G on Jung, Min-Suk Kook, Hong-Ju Park,Sun-Youl Ryu, Hee-Kyun Oh

Departme nt of Oral and Maxillofaci al Surgery, School of Dentistry ,Dental Science Researc h Institute, Chonnam National University,Gwangju, Republic of Korea

Purpose: We are to report cases of dental rehabilitat ion with dis- traction osteogen esis (DO) and dental implant in patients of oral cancer which involved mandible and review of results.

Materials and method s: Patients who received DO and dental implant treatmen ts were selected for evaluation among the oral can- cer patients and their medica l records and radiograp hs were reviewed. Two patients underwent marginal mandibu lectomy and two patien ts underwent segmental mandibule ctomy and recon- struction with fibular free flap. After years of follow-up, all of them were received DO, dental implant installation, and prosthodonti ctreatment s.

Results: On average, 133 ± 33.7 days were taken from the day ofDO to implant installat ion and total 32 implants were installed.Mean follow- up periods after finishing implant prosthetic treat- ments were 47.8 months (27–95 month s), all of the implants were survived through the follow-up period. Patients were satisfied with their restored occlusal function but some of them complained ofrepeated operation and frequen t visiting hospital during the treat- ment period.

Conclusions: DO and subsequ ent dental implant treatmen t on dis- tracted bone, although it takes time and its frequent visiting hospital might be stressful to patients, seems to be safe and stable for dental rehabilitati on after mandibule ctomy.

doi:10.1016/j.oraloncolo gy.2013.03.428

PP186

Chylou s fistula of the neck as a postopera tive complicati on inneck dissection: report of 5 cases and review of the literature Margari ta Vafiadou, George Koloutsos , E. Bourli dou, Maria Lazarid ou,E. Antoniad es, N. Barbetakis, Konstantinos Vahtsevan os, D. Maggou di

Chyle is a milky fluid consisting of lymph/ interstitia l fluid and emulsified fats. The largest conduit of it is in the thoracic duct that starts in the abdomen ascend to the neck and enters the venous system at the junction of the internal jugular vein and the subclavian vein.

Neck dissection can lead to a profuse loss of this milky fluidwhich is protein rich and patients can therefor e become fluiddepleted and malnour ished rapidly with a high output chylous fis-tula. Special feeds can be instituted to decrease output, pressure can also help decrease output. Surgical exploratio n can sometimes localis e the leak. Occasional ly thoracoscop ic ligation of the duct inthe chest can be undertaken . Chylous fistula of the neck is an uncom- mon but significant complicat ion of radical neck dissection s that occurs in about 1–2% of all neck dissections . This complicatio nmay significantly increase the postoperat ive treatmen t or even the morbi dity.

We report five cases of chylous fistula in neck dissect ion that appeared a week to fifteen days following the surgery. The conserva -tive and operative treatment of this complicat ion are presented, aswell as a brief review of the literature.

doi:10.1016/j.oraloncology.2013.03.429

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Merkel cell carcinom a of head and neck region: A case series ofsix patients from northern Greece Ioannis Papadio chos, Margari ta Vafiadou, Nikolaos Kechagi as,C. Andreadi s, A. Patsatsi, B. Christoforid ou,Konstant inos Vahtseva nos, Doxa Mangoudi

Merkel Cell Carcinoma (MCC) is a rare and aggressive primary neuroen docrine carcinoma of the skin. Most patients are in their sev- enth decade or older and only 5% of all reported patients are below the age of 50.

MCC shows a propensity for sun-dama ged skin and it is charac- terized by increased rates of locoregiona l recurrences , distant metas- tases, and disease-relat ed deaths. It is estimated that more than one- half of all cases arise in the head and neck region.

In this retrospec tive study we included all registered cases of pri- mary MCCs of the head and neck which were managed in the Oral and Maxillofa cial Surgery (OMFS) department of Theagenei on Anti- cancer Hospital of Thessaloni ki during the last 11 years. Six patients – 4 women and 2 men – over 62 years of age were identified. Treat- ment selection, response and overall course are described in detail for all patien ts.

Managemen t of head and neck MCCs requires early and accurate diagnos is and includes surgery , radioth erapy, and/or chemothera py.Clinical staging is crucial for any treatment decisions. Since the majority of MCCs arise on the head and neck region, OMF surgeons are among those health care providers, who may be the first toencount er with this disease and should be aware of all treatmen tmodali ties.

doi:10.1016/j.oraloncology.2013.03.432

S156 Abstracts / Oral Oncology 49 (2013) S93–S156