Background There is growing evidence in the literature that older patients may not benefit from more intensive therapy for Head and Neck Squamous Cell Carcinoma (HNSCC). HNSCC patients. There has been an increasing Solithromycin IC50 trend in the receipt of CRT and a decrease in primary surgery. hypotheses, several interaction terms were tested in the models including: age with comorbidity, age with race, race with gender, race and SES indicators, and race with comorbidity. Of note, none of these interaction terms were found to be significant. Model fit was compared using 2-Log Likelihood. All analyses were performed using SAS v9.2. This study was approved by the Institutional Review Board at the University of North Carolina at Chapel Hill (study #10-1985). Results Patient and Treatment Characteristics Median age of all patients was 75 (range 66C106). The majority of patients were Caucasian, male, married, not eligible for Medicaid, and had no comorbidities based on the CCI (Table 2). Oral cavity was the most common primary site in the surgery vs. non-surgery model (43%) and hypopharynx + larynx was the most common in the CRT vs. RT model (49%). Most patients were treated between 2002 and 2007 at cooperative group affiliated hospitals (Table 2). Fifty eight percent (n=6,347) were treated with definitive surgery and Solithromycin IC50 20% (n=2,201) were treated with CRT, of which 30% (n=668) were treated postoperatively. Table 2 Patient clinical and treatment characteristics Surgery vs. Non-surgery Model On multivariate logistic regression comparing patients who received surgery as their primary treatment to those who received non-surgical treatment (i.e. RT or CRT), we observed Solithromycin IC50 that non-oral cavity primary site, regional or unknown stage, and later era of diagnosis were significantly associated with decreased receipt of surgical treatment (Table 3). Female patients were more likely to receive surgery. Of interest, older age (Figure 1a), race, comorbidity, socioeconomic status, SIX3 and hospital affiliation were not significantly associated with receipt of surgery. Figure 1 a: Trend in surgery vs. non-surgery with Solithromycin IC50 increasing age Table 3 Multivariate analysis of surgery vs. non-surgery. Chemoradiotherapy vs. Radiotherapy Model In this model older age (Figure 1b, Table 4), female gender, and hypopharynx/laryngeal cancers were significantly associated with decreased receipt of CRT. Non local stage and oropharyngeal site were significantly associated with Solithromycin IC50 receipt of CRT. Comorbidity status, race, marital status, socioeconomic status, and hospital affiliation correlates were not significantly associated with treatment. Table 4 Multivariate analysis of chemoradiation vs. radiation. Patterns of care over time We observed a decrease in use of surgery and associated increase in nonsurgical treatments (Figure 2a, Table 3) from 1992 to 2007, with the change in treatment trends occurring around the year 2003. In the year 2006 the number of patients treated with surgery and non-surgical treatment were similar (Figure 2a). Furthermore there was an increase in the use of chemotherapy with radiation over the same time period (Figure 2b, Table 4). Figure 2 a: Trend in surgery vs. non-surgery over time. Discussion The purpose of this study was to establish a baseline understanding of the patterns of care for older HNSCC patients and to gain insight into factors associated with receipt of CRT vs. RT and surgery vs. non surgery. Using our cohort of older patients treated in multiple different settings throughout the US, we found that age may be associated with decreased receipt of CRT: i.e. the older the patient, the less likely he/she will be treated with CRT (OR = 0.94; 95% CI 0.93C0.94). However, increasing age was not associated with receipt of surgery (OR 1.00; 95% CI 0.99C1.00). Similarly race and co-morbidity were not associated with receipt of treatment in either model. Not surprisingly, regional stage and non-oral cavity primary tumor site were associated with decreased likelihood of receiving surgery. We also observed that the rate of non-surgical treatment and CRT use has increased over time. The increased utilization is consistent with the publication of clinical trials in the 1990s.