e17001 Background: For the treatment of head and neck cancer (HNC), different modalities (chemotherapy, radiation, surgery, or chemoradiotherapy) can be used either independently or in combination with others. Information regarding real-world treatment pattern is limited. The purpose of this study was to identify common treatment pathways and associated costs. Methods: The study was performed using data from a large U.S. commercial managed care claims database. Adult subjects (≥18) diagnosed with HNC between January 1, 2006, to December 31, 2006, (index-period) were identified based on a pre-selected ICD-9-CM codes. All subjects were HNC diagnosis-naïve 12 months prior to their index dates (first date of HNC diagnosis) and followed for 12 months post index date. Treatment modalities were identified based on the Healthcare Common Procedure Coding System used in the U.S. Pathways were constructed by reflecting time of and between modality administration claims. Results: 6,570 subjects were identified. The average age was 61 years (±14.9) and 44% (n = 2869) were female. Midwest (31%) and east (31%) region had a higher (p < 0.01) representation, compared to south (20%) and west (18%). Only 2,257 subjects (34%) received some type of treatment modality and were categorized into 20 mutually exclusive treatment pathways. Of these, 82% (n = 1,843) received single modality, 18% (n = 398) received a combination of 2, and 0.7% (n = 16) received a combination of 3 modalities. Among single modality pathways, radiation (34%; n = 619) was most common, however, cheomoradiotherapy (26%; n = 485) had the highest average patient cost ($98,440). Within double modalities, radiation followed by chemotherapy (24%; n = 95) was most common, however, chemoradiotherapy followed by surgery (4%; n = 16) had the highest average cost ($146,374). Within triple modalities, surgery followed by radiation then chemotherapy (50%; n = 8) was most common and costly ($95,868). Conclusions: The most common treatment pathways one year post HNC diagnosis used a single modality; however, the average patient costs within multiple modalities were higher. Further study is required to investigate if these patterns are comparable to current guideline recommendation. [Table: see text]