P212

ASSOCIATION FOR ACADEMIC SURGERY AND SOCIETY OF UNIVERSITY SURGEONS—ABSTRACTS

317

treatment. Methods: We reviewed all patients at the United States Army Institute of Surgical Research (USAISR) Burn Center Intensive Care Unit (ICU) admitted over 54 months with a minimum 7 day period of glucose control with insulin treatment. 156 subjects were included and all were treated with insulin managed by protocol. Point-of-care (POC) glucometer glucose values were collected for the first 7 days of admission, and matched between subjects for time of day drawn. Comparison was made among the pooled sample of patients and regression analysis used to investigate glucose trends. Frequency analysis was used to establish the periodicity of patterns in glucose regulation. Results: 86% of patients were hyperglycemic (glucose ⬎ 110 mg/dL) at admission, however values for the group trended down sharply over the first day after initiation of insulin treatment. Despite the decline, average glucose for the 7 day period remained elevated; 82% of measured values were greater than 110 mg/dL (Fig. 1). On day 2 through day 7, a strong diurnal pattern was observed, with troughs at 5 am and peaks at 5 pm, respectively. A paired t-test between a cosine wave and our data renders a correlation of 0.815 (p⬍0.001, Fig. 2). Conclusions: Glucose diurnal variations are preserved in ICU burn patients, with a sinusoidal pattern similar to that seen in normal subjects. Glucose dysregulation is pronounced at admission, and elevated levels persist despite attempts at control.

P212. MELATONIN SECRETION IN URBAN AND RURAL GAMBIANS. S. W. Bickler1, E. Williams2, M. Hayden1, W. Junger1, D. Hoyt1; 1University of California, San Diego, San Diego, CA, 2Medical Research Council Laboratories, Fajara, Gambia Little attention has been given to the neuroendocrine changes that occur with urbanization. To investigate the hypothesis that urban-

318

ASSOCIATION FOR ACADEMIC SURGERY AND SOCIETY OF UNIVERSITY SURGEONS—ABSTRACTS

ization alters pineal gland function, we compared daytime urine 6-sulfatoxymelatonin/Creatinine (6SM/Cr) ratios in rural and urban living adult Gambians (West Africa). Compared to urban living Gambians, Gambians living in a rural village secreted significantly lower levels of daytime 6SM/Cr (p ⬍ .001). We then pursued the hypothesis that lower levels of daytime melatonin in rural areas might be related to poorer sanitation by investigating whether gastrointestinal inflammation affected urine 6SM/Cr ratio in a rat colitis model. Rats administered intra-colonic 2,4,6-trinitrobenzesulfonic acid (TNBS) had significantly lower urine 6-SM/Cr levels on day 4 compared to controls (p ⬍ .05). Considered together, these preliminary data suggests that urbanization alters daytime melatonin secretion, and that one potential factor might be varying rates of gastrointestinal inflammation. Further research is needed to investigate the fundamental relationship between naturally occurring inflammation/infection and pineal gland function, and the neuroendocrine consequences of transitioning from a rural to an urban environment.

ONCOLOGY XI: CLINICAL OUTCOMES P213. RISK OF MALIGNANCY IN RESECTED CYSTIC TUMORS OF THE PANCREAS < 3 CM IN SIZE: IS IT SAFE TO OBSERVE ASYMPTOMATIC PATIENTS. C. Lee, J. Scheiman, D. Simeone; Uinversity of Michigan, Ann Arbor, MI Introduction: Recent international consensus guidelines for the management of cystic neoplasms of the pancreas propose that all cystic pancreatic tumors less than 3 cm in size in asymptomatic patients with no radiographic features concerning for malignancy are safe to observe, however there is little published data to support this recommendation. The purpose of this study was to determine the incidence of malignancy in this group of patients using a large, single center pancreatic resection database as an initial method to assess the appropriateness of these guidelines. Methods: All pancreatic resections performed for cystic neoplasms ⬍ 3 cm in size were evaluated over the time period of 1998-2006 at a high volume pancreatic surgical center. Sixty one cases were identified and the clinical, radiographic, and pathological data was reviewed. Factors analyzed as potential predictors of malignancy included age, gender, and symptoms (abdominal pain, nausea and vomiting, jaundice, presence of pancreatitis, and unexplained weight loss) and radiographic features suggestive of malignancy by either CT scanning or EUS (presence of solid component, dilated main pancreatic duct, or lymphadenopathy). Results: Among 115 pancreatic resections for cystic pancreatic neoplasms over the eight year period of study, 61 cases of resection for cystic tumors ⬍ 3 cm were identified. Of these 61 cases, 47 cases were of benign (15 serous cystadenomas, 13 mucinous cystic neoplasms (MCN), 18 intraductal papillary mucinous neoplasms (IPMN), and 1 cystic papillary tumor), while 12 cases were malignant (8 mucinous cystic adenocarcinoma, 4 carcinomas arising in a setting of IPMN). A greater incidence of cystic neoplasms was seen in females (39/61, 64%), however gender was not a predictor for malignant pathology. Older age was associated with malignancy (mean age 67 yrs. in patients with malignant disease vs. 60 yrs. in patients with benign lesions (p⬍0.05). All 14 patients with malignancy were symptomatic, with abdominal pain (83%) the most common symptom, followed by pancreatitis (20%), weight loss (13%), jaundice (13%), and nausea/vomiting (10%). In addition, all 14 patients with malignant lesions had radiographic features concerning for malignancy. Of the patients with benign disease, 14/47 (30%) were asymptomatic and had no radiographic features concerning for malignancy. Of the remaining 33 patients with benign disease, all were symptomatic and (8/33, 24%) had concerning radiographic features. Conclusions: As all patients with malignancy had both symptoms and abnormal imaging, our data from a single high volume center support the guidelines proposed by the International Consensus Conference. We conclude that the risk of malignancy in asymp-

tomatic patients with pancreatic cystic tumors ⬍ 3 cm and no worrisome radiographic features is negligible. These data will be validated by a larger, multi-institutional study. P214. BREAST CANCER SUBTYPES IN PREMENOPAUSAL AFRICAN AMERICAN WOMEN. C. Ihemelandu 1, W. Federick 2; 1Howard University Cancer Center, Washington, DC, 2 Howard University Hospital, Washington, DC Introduction: Currently breast cancer is being viewed as a heterogeneous disease made up of various subtypes: luminal, basal, and HER-2, with distinct differences in prognosis and response to therapy. Our aim was to study the distribution, prevalence and clinical association for triple negative “basal cell-like” breast cancer and other breast cancer subtypes amongst pre-menopausal AfricanAmerican women. Methods: A retrospective analysis of data obtained from the Howard University tumor and pathology registry. The study population included all assessable pre-menopausal ⬍50yrs breast cancer patients, diagnosed between 1998-2005 at Howard University Hospital (n⫽129). These patients were stratified into two groups: - 1) ⬍ 35yrs, 2) ⬎ 35yrs. We studied the prevalence of triple negative (basal cell-like) breast cancer and other breast cancer subtypes amongst these cohorts of pre-menopausal AfricanAmerican women, and determined there clinical association with histology and histological grade of the tumors, tumor size, nodal status, p53 mutation status, and breast cancer-specific survival. The subtypes analyzed were: - (a) Luminal A: - (ER ⫹ and/or PR⫹, HER2-), (b) Luminal B: - (ER⫹ and/or PR⫹, HER2⫹), (c) Basal cell-like (ER-, PR-, HER2-), (d) HER2⫹: - (ER-, PR-, and HER2⫹). Results: The luminal A breast cancer subtype was more prevalent amongst the pre-menopausal African-American women (54.9%), compared with the basal cell-like breast cancer subtype (19.7%), luminal B breast cancer subtype (13%) and HER-2/neu breast cancer subtype (12.3%). However when stratified by age, our results showed the basal cell-like breast cancer subtype to be more prevalent (55%) (P⬍. 001) among the pre-menopausal African-American women ⬍ 35yrs old when compared to those ⬎ 35yrs old, and the luminal A breast cancer subtype to be more prevalent among the patients ⬎ 35yrs. The luminal B and HER-2/neu subtypes did not show any variation with age. Compared with luminal A, the basal cell-like breast cancer subtypes were more likely to be associated with p53 mutation (50% vs. 15.3%, P⫽ .003), and an under expression of the BCL-2 proto-oncogene. Breast cancer specific survival differed by subtype with the shortest survival among the basal cell-like subtype. Conclusion: Breast cancer in pre-menopausal African-American women ⬍ 35yrs old is more likely to be of the basal cell-like subtype, with associated p53 mutation, under expression of the BCL-2 protooncogene and shortened survival. This high prevalence of the basal cell-like subtype, with the associated p53 mutation and under expression of BCL-2 proto-oncogene could contribute to the poor prognosis of breast cancer in young pre-menopausal African-American women. P215. AN AUDIT OF LYMPH NODE RETRIEVAL IN COLORECTAL CANCER PATIENTS AT A RURAL ACADEMIC CENTER. R. S. Zuckerman, C. A. Henson; MIBH, Cooperstown, NY Background: Both the American Joint Committee on Cancer and The International Union Against Cancer recommend a minimum of 12 lymph nodes to accurately stage a colorectal cancer patient. In a recent national review of 116995 colorectal cancer cases by Baxter et al (Journal of the National Cancer Institute 2005;97:219-225) only 37% received adequate lymph node sampling at the time of tumor resection. Given the alarming implications of these findings, we conducted a review of lymph node retrieval in our own colorectal cancer cases. Methods: A retrospective review of newly diagnosed colorectal cancer cases from 2003 to mid-2004 was performed. Of the