Endoscopic Margins of Skull-base Tumors: Oncologically Safe? Marc A. Cohen, MD (presenter); Jonathan Liang; Bert W O’Malley, Jr, MD; Jason G Newman, MD OBJECTIVE: 1) Learn if margins of resection in anterior skull base tumors that are entirely or endoscopic-assisted are com- parable with those undergoing traditional craniofacial resec- tion. 2) Understand if there is a difference in patient mortality with traditional CFR compared to endoscopic-assisted surgery. METHODS: Retrospective review was conducted of patients undergoing surgery at our institution for malignant lesions of the anterior skull base between 2000-2006. 46 patients were identified. 20 underwent endoscopic-assisted or total endo- scopic resection. Margins were evaluated by the pathologist. Recurrence rates were calculated based on the presence or absence of recurrence at the last office visit. Follow-up times ranged from 1 month to 5 years. RESULTS: Of the 20 patients undergoing endoscopic or en- doscopic assisted CFR of anterior skull base lesions, 15/20 patients had negative margins (75%), 4/20 had positive mar- gins (20%), and 1/20 had close margins (5%). In those patients undergoing traditional CFR, 17/26 patients had negative mar- gins (65%), 8/26 had positive margins (30%), and 1/26 (4%) had close margins. Recurrence was noted in 9/26 (35%) of those who underwent traditional CFR and 6/20 (30%) of those with endoscopic assistance. CONCLUSIONS: There does not appear to be increased risk of positive margins or recurrence in those undergoing end- scopic or endoscopic-assisted resection. Endoscopy may aid in identifying margins of tumor in the anterior skull base, leading to a greater likelihood of cure. Endoscopic resections have the potential to avoid morbity and should be considered oncologi- cally sound in the appropriate patient with a skull base lesion. FAS and FASL Polymorphisms in Oral / Oropharyngeal Cancer Carlos Neutzling Lehn, MD, PhD (presenter); Ivo Marquis Beserra, Jr; Paulo Carvalho, MD; Adriana Silva, MD; Marcos Carvalho, MD; Viviane Santos, MD OBJECTIVE: Examine the hypothesis if genetic polymor- phisms in FAS and FASL genes, alone or in combination, are associated with oral and oropharyngeal squamous-cell carci- noma. METHODS: Prospective study based on 225 pacients with oral and oropharyngeal squamous-cell carcinoma and 215 con- trols, analyzed with PCR-RFLP. RESULTS: We observed a statistically significantly increased risk of oral and oropharyngeal squamous-cell carcinoma asso- ciated with the FASL -844 CT genotype (p=0,031). An in- creased risk of oral and oropharyngeal squamous-cell carci- noma was also associated with the FASL -844 T allele (p=0,04). Gene-gene interactions of FAS and FASL polymor- phisms increased the risk of oral and oropharyngeal squamous- cell carcinoma in a multiplicative manner (p=0,04). CONCLUSIONS: The results suggest that the presence of the allele T of FASL and its combination with G allele potentially increase the risk of cancer development. Female Gender: A Post-Thyroidectomy Hypocalcemia Risk Factor Noah Benjamin Sands, BSc, MDCM (presenter); Valerie Cote, MD; Michael Tamilia, MD, FRCP; Michael P Hier, MD; Martin J Black, FRCS(C); Richard J Payne MD, MSc, FRCS OBJECTIVE: 1) To evaluate the role of patient gender as a potential risk factor for post-thyroidectomy hypocalcemia. 2)To elucidate, from previous studies, potential physiologic mechanisms underlying any identified gender disparity. 3)To help better predict post-thyroidectomy hypocalcemia and ulti- mately limit its incidence with prophylactic/early calcium sup- plementation. METHODS: A retrospective review of 270 consecutive total thyroidectomy patients (October 2004-December 2006) was conducted, consisting of 219 females and 51 males. Postoper- ative hypocalcemia was defined as any one of the following: total serum calcium of less than or equal to 1.90 mmol/L up to 1 month following surgery or symptoms of hypocalcemia. The following were evaluated as potential confounding factors in the study: age, menopause, pre-operative calcium and parathy- roid hormone levels, magnesium and phosphate levels, pathol- ogy and number of parathyroid glands preserved in situ. Chi- squared testing was used to evaluate for statistical significance. RESULTS: Female patients experienced transient postopera- tive hypocalcemia in 24.7% (54/219) of cases, which was significantly greater than the 11.8% (6/51) incidence detected in males (p less than 0.05). This represents a female:male relative risk ratio of 2.1 (C.I. 1.0-4.6). There was no significant difference in rates of hypocalcemia between pre-menopausal (age less than 50) and post-menopausal women (22.7% vs. 26.6%). CONCLUSIONS: These findings suggest that being female is a significant risk factor for transient post-thyroidectomy hy- pocalcemia. Furthermore, females appear to experience this postoperative complication more than twice as frequently as males. Additional research is needed in order to ascertain the physiologic mechanisms underlying this identified gender dif- ference. Fine Needle Aspiration Analysis of B-RAF in Thyroid Nodules Brandon G Bentz, MD (presenter); Brian Thomas Miller, MD; Joseph Holden, MD; Leslie R Rowe; Joel Bentz, MD P37 Scientific Oral Presentations SCI. ORALS