2429 The Prognostic Significance of EGFR Expression in African American Patients With Squamous CellCarcinomas of the Head and Neck

K. M. Settle, R. Taylor, J. Papadimitriou, N. Carter-Monroe, N. Murali, J. Wolf, K. Cullen, M. Suntharalingam

University of Maryland School of Medicine, Baltimore, MD

Purpose/Objective(s): To determine the prognostic significance of EGFR expression in African American (AA) patients (pts)who received concurrent chemoradiation for locally advanced SCC H&N.

Materials/Methods: We performed a retrospective analysis of 103 patients with Stage III/IV SCC H&N, who were treated atthe University of Maryland between 1997 and 2003. All patients received daily RT, to a total dose of 70.2Gy (1.8Gy/day),concurrently with weekly Carboplatin (100mg/m2) and Paclitaxel (45mg/m2). This initial analysis revealed a significantlyworse outcome for AA pts in terms of median survival, disease recurrence, and distant failure. Based on these findings, acorrelative pathological study was performed on 20 AA pts tissue specimens to determine the impact of EGFR expression onoutcome.

A total of 20 paraffin tissue sections were stained for antibody against EGFR using the Ventana Benchmark system. Thestained slides were then analyzed using ChromaVision Automated Cellular Imaging System. Image capture technology wasused to quantify EGFR staining positivity based on color, color purity, and intensity. Staining Intensity (SI) was reported interms of staining intensity (SI) on a scale of 0 to 97. The ACIS score (SC) of 0 to 4� was documented in order to reflect IHCpositivity by visual inspection.

Results: The initial cohort of 103 patients (58% Caucasian and 42% AA) was similar with respect to age, gender, clinical stage,and tumor site. The median survival (MS) for the entire group was 30 months. AA pts had a higher rate of disease recurrencecompared to CAU pts, 57% versus 37% (p�0.05). In addition, AA pts had a higher rate of distant failure, 27% versus 12% (p�0.06). On multivariate analysis, factors which predicted for recurrence included race (p�0.02) and stage of disease (p�0.05).

Among the 20 AA tissue samples, all stained IHC positive for EGFR. Average SC staining based on tumor differentiationis as follows: Well to moderately differentiated SC� 3.2; moderately differentiated SC �2.9; moderately to poorly differen-tiated SC� 2.8; and poorly differentiated SC� 2.4. The median SI for the entire cohort was 67.5. Pts who’s SI ranged abovethe median, had a MS of 34 months and 2 year and 5 year OS 60% and 32%, respectively. Pts who’s SI ranged below themedian, had a MS of 71 months and a 2 year and 5 year OS of 75% and 60%, respectively.

Conclusions: This preliminary analysis of IHC staining among AA pts suggests that EGFR expression may play a role inpredicting response to concurrent chemoradiation. Further analysis of existing patient data will be necessary to validate theseinitial findings. Continued exploration of potential differences in cell surface receptor expression is critical as we continue tointegrate biologic therapies into current chemoradiation strategies.

Author Disclosure: K.M. Settle, None; R. Taylor, None; J. Papadimitriou, None; N. Carter-Monroe, None; N. Murali, None;J. Wolf, None; K. Cullen, None; M. Suntharalingam, BMS, Imclone, Aventis, Roche, MedImmune, B. Research Grant; BMS,Imclone, MedImmune, D. Speakers Bureau/Honoraria; BMS, Imclone, MedImmune, F. Consultant/Advisory Board.

2430 Prospective Phase II Trial of Concomitant Boost Radiotherapy for Stage II Nasopharyngeal Carcinoma

J. J. Lu1, L. Kong2,3, K. Loh1, T. P. Shakespeare1, A. Thiagarajan1, K. Tan1

1National University Hospital, ,Singapore, Singapore, 2Cancer Hospital of Fudan University, Shanghai, China,3National University Hospital, Singapore, Singapore

Background: The long-term local control rates for Stage II nasopharyngeal carcinoma (NPC) after conventional radiationtherapy is approximately 70%. Radiation therapy using accelerated concomitant boost schedule has been proven to beefficacious in treating locally advanced head and neck cancers.

Purpose/Objective(s): The aim of this trial is to study the outcome of Stage II NPC patients treated with external beamradiotherapy delivered using a concomitant boost schedule.

Materials/Methods: Forty-two patients with pathologically confirmed Stage II (1997 AJCC Classification) undifferentiatednasopharyngeal carcinoma were enrolled and analyzed in this prospective phase II trial. The primary tumor and clinicallyinvolved nodes received a total dose of 72 Gy in 42 fractions. Concomitant boost radiation for gross disease consisted of 18Gy in 12 fractions commencing on day 19 and was delivered at least 6 hours after the first daily dose of 1.8 Gy. All patientswere assessed for response, survival, and toxicity.

Results: With a median follow-up of 28 months, 5 patients developed pathologically confirmed local recurrence, necessitatingIMRT or surgery, 2 developed neck recurrence and were treated with neck dissection or chemotherapy, and 3 were treated withsystemic chemotherapy for their distant relapses. One patient who had persistent neck lymphadenopathy and declined furthertreatment developed and died of distant metastasis. In addition, 3 patients died of distant metastasis only, and 1 patient died frombleeding secondary to nasopharyngectomy for local recurrence. The 2-year local control, regional control, and overall survivalrates were 92.5%, 95.1%, and 90.7%, respectively; and those of three years were 82.4%, 89.5%, and 83.0 %, respectively.

All patients experienced some degree of acute and/or late toxicity. Grade 3 trismus, soft tissue fibrosis, hearing loss, andcranial nerve palsy were seen in 1, 1, 3, and 1 patients, respectively. No patient had grade 4 or 5 toxicity after their definitiveradiotherapy. The toxicity profile was comparable to that seen following standard fractionation. Acute or late toxicities directlyattributable to concomitant boost radiation were not observed.

Conclusions: This concomitant boost radiation regimen administers a substantially higher biologically effective dose comparedwith conventional radiation schedules. This radiation schedule may produce improved local and regional control rates withoutsignificant acute and/or late toxicities.

Author Disclosure: J.J. Lu, None; L. Kong, None; K. Loh, None; T.P. Shakespeare, None; A. Thiagarajan, None; K. Tan, None.

S448 I. J. Radiation Oncology ● Biology ● Physics Volume 66, Number 3, Supplement, 2006